bif: Add BIF core framework driver
Add a BIF framework which implements core features of the MIPI
(Mobile Industry Processor Interace) BIF (Battery Interface)
specification. MIPI-BIF defines an interface which can be used
to communicate with smart battery packs.
BIF controller drivers register with the BIF framework and
implement hardware specific features. BIF consumers can make use
of an extensive API to communicate with BIF slaves present on a
BIF bus.
Change-Id: Id640344aadf878a49e93b12b16a5ecb181dd5aeb
Signed-off-by: David Collins <collinsd@codeaurora.org>
diff --git a/drivers/Kconfig b/drivers/Kconfig
index a73d713..adead10 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -150,4 +150,6 @@
source "drivers/coresight/Kconfig"
+source "drivers/bif/Kconfig"
+
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index f461e83..d55b035 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -142,3 +142,5 @@
obj-$(CONFIG_MOBICORE_SUPPORT) += gud/
obj-$(CONFIG_CORESIGHT) += coresight/
+
+obj-$(CONFIG_BIF) += bif/
diff --git a/drivers/bif/Kconfig b/drivers/bif/Kconfig
new file mode 100644
index 0000000..502b92b
--- /dev/null
+++ b/drivers/bif/Kconfig
@@ -0,0 +1,12 @@
+#
+# BIF framework and drivers
+#
+menuconfig BIF
+ bool "MIPI-BIF support"
+ select CRC_CCITT
+ select BITREVERSE
+ help
+ MIPI-BIF (battery interface) is a one-wire serial interface between a
+ host master device and one or more slave devices which are located in
+ a battery pack or also on the host. Enabling this option allows for
+ BIF consumer drivers to issue transactions via BIF controller drivers.
diff --git a/drivers/bif/Makefile b/drivers/bif/Makefile
new file mode 100644
index 0000000..02528c1
--- /dev/null
+++ b/drivers/bif/Makefile
@@ -0,0 +1,4 @@
+#
+# Makefile for kernel BIF framework.
+#
+obj-$(CONFIG_BIF) += bif-core.o
diff --git a/drivers/bif/bif-core.c b/drivers/bif/bif-core.c
new file mode 100644
index 0000000..e11e6ba4
--- /dev/null
+++ b/drivers/bif/bif-core.c
@@ -0,0 +1,2934 @@
+/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/bitrev.h>
+#include <linux/crc-ccitt.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/workqueue.h>
+#include <linux/bif/consumer.h>
+#include <linux/bif/driver.h>
+
+/**
+ * struct bif_ctrl_dev - holds controller device specific information
+ * @list: Doubly-linked list parameter linking to other
+ * BIF controllers registered in the system
+ * @desc: Description structure for this BIF controller
+ * @mutex: Mutex lock that is used to ensure mutual
+ * exclusion between transactions performed on the
+ * BIF bus for this controller
+ * @ctrl_dev: Device pointer to the BIF controller device
+ * @driver_data: Private data used by the BIF controller
+ * @selected_sdev: Slave device that is currently selected on
+ * the BIF bus of this controller
+ * @bus_change_notifier: Head of a notifier list containing notifier
+ * blocks that are notified when the battery
+ * presence changes
+ * @enter_irq_mode_work: Work task that is scheduled after a transaction
+ * completes when there are consumers that are
+ * actively monitoring BIF slave interrupts
+ * @irq_count: This is a count of the total number of BIF slave
+ * interrupts that are currently being monitored
+ * for the BIF slaves connected to this BIF
+ * controller
+ * @irq_mode_delay_jiffies: Number of jiffies to wait before scheduling the
+ * enter IRQ mode task. Using a larger value
+ * helps to improve the performance of BIF
+ * consumers that perform many BIF transactions.
+ * Using a smaller value reduces the latency of
+ * BIF slave interrupts.
+ * @battery_present: Cached value of the battery presence. This is
+ * used to filter out spurious presence update
+ * calls when the battery presence state has not
+ * changed.
+ */
+struct bif_ctrl_dev {
+ struct list_head list;
+ struct bif_ctrl_desc *desc;
+ struct mutex mutex;
+ struct device *ctrl_dev;
+ void *driver_data;
+ struct bif_slave_dev *selected_sdev;
+ struct blocking_notifier_head bus_change_notifier;
+ struct delayed_work enter_irq_mode_work;
+ int irq_count;
+ int irq_mode_delay_jiffies;
+ bool battery_present;
+};
+
+/**
+ * struct bif_ctrl - handle used by BIF consumers for bus oriented BIF
+ * operations
+ * @bdev: Pointer to BIF controller device
+ * @exclusive_lock: Flag which indicates that the BIF consumer responsible
+ * for this handle has locked the BIF bus of this
+ * controller. BIF transactions from other consumers are
+ * blocked until the bus is unlocked.
+ */
+struct bif_ctrl {
+ struct bif_ctrl_dev *bdev;
+ bool exclusive_lock;
+};
+
+/**
+ * struct bif_slave_dev - holds BIF slave device information
+ * @list: Doubly-linked list parameter linking to other
+ * BIF slaves that have been enumerated
+ * @bdev: Pointer to the BIF controller device that this
+ * slave is physically connected to
+ * @slave_addr: 8-bit BIF DEV_ADR assigned to this slave
+ * @unique_id: 80-bit BIF unique ID of the slave
+ * @unique_id_bits_known: Number of bits of the UID that are currently
+ * known. This number starts is incremented during
+ * a UID search and must end at 80 if the slave
+ * responds to the search properly.
+ * @present: Boolean value showing if this slave is
+* physically present in the system at a given
+* point in time. The value is set to false if the
+* battery pack containing the slave is
+* disconnected.
+ * @l1_data: BIF DDB L1 data of the slave as read from the
+ * slave's memory
+ * @function_directory: Pointer to the BIF DDB L2 function directory
+ * list as read from the slave's memory
+ * @protocol_function: Pointer to constant protocol function data as
+ * well as software state information if the slave
+ * has a protocol function
+ * @slave_ctrl_function: Pointer to constant slave control function data
+ * as well as software state information if the
+ * slave has a slave control function
+ * @nvm_function: Pointer to constant non-volatile memory function
+ * data as well as software state information if
+ * the slave has a non-volatile memory function
+ *
+ * bif_slave_dev objects are stored indefinitely after enumeration in order to
+ * speed up battery reinsertion. Only a UID check is needed after inserting a
+ * battery assuming it has been enumerated before.
+ *
+ * unique_id bytes are stored such that unique_id[0] = MSB and
+ * unique_id[BIF_UNIQUE_ID_BYTE_LENGTH - 1] = LSB
+ */
+struct bif_slave_dev {
+ struct list_head list;
+ struct bif_ctrl_dev *bdev;
+ u8 slave_addr;
+ u8 unique_id[BIF_UNIQUE_ID_BYTE_LENGTH];
+ int unique_id_bits_known;
+ bool present;
+ struct bif_ddb_l1_data l1_data;
+ struct bif_ddb_l2_data *function_directory;
+ struct bif_protocol_function *protocol_function;
+ struct bif_slave_control_function *slave_ctrl_function;
+ struct bif_nvm_function *nvm_function;
+};
+
+/**
+ * struct bif_slave - handle used by BIF consumers for slave oriented BIF
+ * operations
+ * @ctrl: Consumer BIF controller handle data
+ * @sdev: Pointer to BIF slave device
+ */
+struct bif_slave {
+ struct bif_ctrl ctrl;
+ struct bif_slave_dev *sdev;
+};
+
+/* Number of times to retry a full BIF transaction before returning an error. */
+#define BIF_TRANSACTION_RETRY_COUNT 5
+
+static DEFINE_MUTEX(bif_ctrl_list_mutex);
+static LIST_HEAD(bif_ctrl_list);
+static DEFINE_MUTEX(bif_sdev_list_mutex);
+static LIST_HEAD(bif_sdev_list);
+
+static u8 next_dev_addr = 0x02;
+
+#define DEBUG_PRINT_BUFFER_SIZE 256
+static void fill_string(char *str, size_t str_len, u8 *buf, int buf_len)
+{
+ int pos = 0;
+ int i;
+
+ for (i = 0; i < buf_len; i++) {
+ pos += scnprintf(str + pos, str_len - pos, "0x%02X", buf[i]);
+ if (i < buf_len - 1)
+ pos += scnprintf(str + pos, str_len - pos, ", ");
+ }
+}
+
+static void bif_print_slave_data(struct bif_slave_dev *sdev)
+{
+ char str[DEBUG_PRINT_BUFFER_SIZE];
+ u8 *uid;
+ int i, j;
+ struct bif_object *object;
+
+ if (sdev->unique_id_bits_known != BIF_UNIQUE_ID_BIT_LENGTH)
+ return;
+
+ uid = sdev->unique_id;
+ pr_debug("BIF slave: 0x%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X\n",
+ uid[0], uid[1], uid[2], uid[3], uid[4], uid[5], uid[6],
+ uid[7], uid[8], uid[9]);
+ pr_debug(" present=%d, dev_adr=0x%02X\n", sdev->present,
+ sdev->slave_addr);
+ pr_debug(" revision=0x%02X, level=0x%02X, device class=0x%04X\n",
+ sdev->l1_data.revision, sdev->l1_data.level,
+ sdev->l1_data.device_class);
+ pr_debug(" manufacturer ID=0x%04X, product ID=0x%04X\n",
+ sdev->l1_data.manufacturer_id, sdev->l1_data.product_id);
+ pr_debug(" function directory length=%d\n", sdev->l1_data.length);
+
+ for (i = 0; i < sdev->l1_data.length / 4; i++) {
+ pr_debug(" Function %d: type=0x%02X, version=0x%02X, pointer=0x%04X\n",
+ i, sdev->function_directory[i].function_type,
+ sdev->function_directory[i].function_version,
+ sdev->function_directory[i].function_pointer);
+ }
+
+ if (sdev->nvm_function) {
+ pr_debug(" NVM function: pointer=0x%04X, task=%d, wr_buf_size=%d, nvm_base=0x%04X, nvm_size=%d\n",
+ sdev->nvm_function->nvm_pointer,
+ sdev->nvm_function->slave_control_channel,
+ (sdev->nvm_function->write_buffer_size
+ ? sdev->nvm_function->write_buffer_size : 0),
+ sdev->nvm_function->nvm_base_address,
+ sdev->nvm_function->nvm_size);
+ if (sdev->nvm_function->object_count)
+ pr_debug(" NVM objects:\n");
+ i = 0;
+ list_for_each_entry(object, &sdev->nvm_function->object_list,
+ list) {
+ pr_debug(" Object %d - addr=0x%04X, data len=%d, type=0x%02X, version=0x%02X, manufacturer ID=0x%04X, crc=0x%04X\n",
+ i, object->addr, object->length - 8,
+ object->type, object->version,
+ object->manufacturer_id, object->crc);
+ for (j = 0; j < DIV_ROUND_UP(object->length - 8, 16);
+ j++) {
+ fill_string(str, DEBUG_PRINT_BUFFER_SIZE,
+ object->data + j * 16,
+ min(16, object->length - 8 - (j * 16)));
+ pr_debug(" data(0x%04X): %s\n", j * 16,
+ str);
+ }
+ i++;
+ }
+ }
+}
+
+static void bif_print_slaves(void)
+{
+ struct bif_slave_dev *sdev;
+
+ mutex_lock(&bif_sdev_list_mutex);
+
+ list_for_each_entry(sdev, &bif_sdev_list, list) {
+ /* Skip slaves without fully known UIDs. */
+ if (sdev->unique_id_bits_known != BIF_UNIQUE_ID_BIT_LENGTH)
+ continue;
+ bif_print_slave_data(sdev);
+ }
+
+ mutex_unlock(&bif_sdev_list_mutex);
+}
+
+static struct bif_slave_dev *bif_add_slave(struct bif_ctrl_dev *bdev)
+{
+ struct bif_slave_dev *sdev;
+
+ sdev = kzalloc(sizeof(struct bif_slave_dev), GFP_KERNEL);
+ if (sdev == NULL) {
+ pr_err("Memory allocation failed for bif_slave_dev\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ sdev->bdev = bdev;
+ INIT_LIST_HEAD(&sdev->list);
+ list_add_tail(&sdev->list, &bif_sdev_list);
+
+ return sdev;
+}
+
+static void bif_remove_slave(struct bif_slave_dev *sdev)
+{
+ list_del(&sdev->list);
+ if (sdev->bdev->selected_sdev == sdev)
+ sdev->bdev->selected_sdev = NULL;
+
+ if (sdev->slave_ctrl_function)
+ kfree(sdev->slave_ctrl_function->irq_notifier_list);
+ kfree(sdev->slave_ctrl_function);
+ kfree(sdev->protocol_function);
+ kfree(sdev->function_directory);
+
+ kfree(sdev);
+}
+
+/* This function assumes that the uid array is all 0 to start with. */
+static void set_uid_bit(u8 uid[BIF_UNIQUE_ID_BYTE_LENGTH], unsigned int bit,
+ unsigned int value)
+{
+ u8 mask;
+
+ if (bit >= BIF_UNIQUE_ID_BIT_LENGTH)
+ return;
+
+ mask = 1 << (7 - (bit % 8));
+
+ uid[bit / 8] &= ~mask;
+ uid[bit / 8] |= value << (7 - (bit % 8));
+}
+
+static unsigned int get_uid_bit(u8 uid[BIF_UNIQUE_ID_BYTE_LENGTH],
+ unsigned int bit)
+{
+ if (bit >= BIF_UNIQUE_ID_BIT_LENGTH)
+ return 0;
+
+ return (uid[bit / 8] & (1 << (7 - (bit % 8)))) ? 1 : 0;
+}
+
+static void bif_enter_irq_mode_work(struct work_struct *work)
+{
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct bif_ctrl_dev *bdev
+ = container_of(dwork, struct bif_ctrl_dev, enter_irq_mode_work);
+ int rc, i;
+
+ mutex_lock(&bdev->mutex);
+ for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+ rc = bdev->desc->ops->set_bus_state(bdev,
+ BIF_BUS_STATE_INTERRUPT);
+ if (rc == 0)
+ break;
+ }
+ mutex_unlock(&bdev->mutex);
+
+ /* Reschedule the task if the transaction failed. */
+ if (rc) {
+ pr_err("Could not set BIF bus to interrupt mode, rc=%d\n", rc);
+ schedule_delayed_work(&bdev->enter_irq_mode_work,
+ bdev->irq_mode_delay_jiffies);
+ }
+}
+
+static void bif_cancel_irq_mode_work(struct bif_ctrl_dev *bdev)
+{
+ cancel_delayed_work(&bdev->enter_irq_mode_work);
+}
+
+static void bif_schedule_irq_mode_work(struct bif_ctrl_dev *bdev)
+{
+ if (bdev->irq_count > 0 &&
+ bdev->desc->ops->get_bus_state(bdev) != BIF_BUS_STATE_INTERRUPT)
+ schedule_delayed_work(&bdev->enter_irq_mode_work,
+ bdev->irq_mode_delay_jiffies);
+}
+
+static int _bif_select_slave_no_retry(struct bif_slave_dev *sdev)
+{
+ struct bif_ctrl_dev *bdev = sdev->bdev;
+ int rc = 0;
+ int i;
+
+ /* Check if the slave is already selected. */
+ if (sdev->bdev->selected_sdev == sdev)
+ return 0;
+
+ if (sdev->slave_addr) {
+ /* Select using DEV_ADR. */
+ rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_SDA,
+ sdev->slave_addr);
+ if (!rc)
+ sdev->bdev->selected_sdev = sdev;
+ } else if (sdev->unique_id_bits_known == BIF_UNIQUE_ID_BIT_LENGTH) {
+ /* Select using full UID. */
+ for (i = 0; i < BIF_UNIQUE_ID_BYTE_LENGTH - 1; i++) {
+ rc = bdev->desc->ops->bus_transaction(bdev,
+ BIF_TRANS_EDA, sdev->unique_id[i]);
+ if (rc)
+ goto out;
+ }
+
+ rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_SDA,
+ sdev->unique_id[BIF_UNIQUE_ID_BYTE_LENGTH - 1]);
+ if (rc)
+ goto out;
+ } else {
+ pr_err("Cannot select slave because it has neither UID nor DEV_ADR.\n");
+ return -EINVAL;
+ }
+
+ sdev->bdev->selected_sdev = sdev;
+
+ return 0;
+out:
+ pr_err("bus_transaction failed, rc=%d\n", rc);
+ return rc;
+}
+
+static int bif_select_slave(struct bif_slave_dev *sdev)
+{
+ int rc = -EPERM;
+ int i;
+
+ for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+ rc = _bif_select_slave_no_retry(sdev);
+ if (rc == 0)
+ break;
+ /* Force slave reselection. */
+ sdev->bdev->selected_sdev = NULL;
+ }
+
+ return rc;
+}
+
+/*
+ * Returns 1 if slave is selected, 0 if slave is not selected, or errno if
+ * error.
+ */
+static int bif_is_slave_selected(struct bif_ctrl_dev *bdev)
+{
+ int rc = -EPERM;
+ int tack, i;
+
+ for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+ /* Attempt a transaction query. */
+ rc = bdev->desc->ops->bus_transaction_read(bdev, BIF_TRANS_BC,
+ BIF_CMD_TQ, &tack);
+ if (rc == 0 || rc == -ETIMEDOUT)
+ break;
+ }
+
+ if (rc == 0)
+ rc = 1;
+ else if (rc == -ETIMEDOUT)
+ rc = 0;
+ else
+ pr_err("BIF bus_transaction_read failed, rc=%d\n", rc);
+
+ return rc;
+}
+
+/* Read from a specified number of consecutive registers. */
+static int _bif_slave_read_no_retry(struct bif_slave_dev *sdev, u16 addr,
+ u8 *buf, int len)
+{
+ struct bif_ctrl_dev *bdev = sdev->bdev;
+ int rc = 0;
+ int i, response;
+
+ rc = bif_select_slave(sdev);
+ if (rc)
+ return rc;
+
+ if (bdev->desc->ops->read_slave_registers) {
+ /*
+ * Use low level slave register read implementation in order to
+ * receive the benefits of BIF burst reads.
+ */
+ rc = bdev->desc->ops->read_slave_registers(bdev, addr, buf,
+ len);
+ if (rc)
+ pr_err("read_slave_registers failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ for (i = 0; i < len; i++) {
+ rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_ERA,
+ addr >> 8);
+ if (rc) {
+ pr_err("bus_transaction failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ rc = bdev->desc->ops->bus_transaction_read(bdev, BIF_TRANS_RRA,
+ addr & 0xFF, &response);
+ if (rc) {
+ pr_err("bus_transaction_read failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ if (!(response & BIF_SLAVE_RD_ACK)) {
+ pr_err("BIF register read error=0x%02X\n",
+ response & BIF_SLAVE_RD_ERR);
+ return -EIO;
+ }
+
+ buf[i] = response & BIF_SLAVE_RD_DATA;
+ addr++;
+ }
+
+ return rc;
+}
+
+/*
+ * Read from a specified number of consecutive registers. Retry the transaction
+ * several times in case of communcation failures.
+ */
+static int _bif_slave_read(struct bif_slave_dev *sdev, u16 addr, u8 *buf,
+ int len)
+{
+ int rc = -EPERM;
+ int i;
+
+ for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+ rc = _bif_slave_read_no_retry(sdev, addr, buf, len);
+ if (rc == 0)
+ break;
+ /* Force slave reselection. */
+ sdev->bdev->selected_sdev = NULL;
+ }
+
+ return rc;
+}
+
+/* Write to a specified number of consecutive registers. */
+static int _bif_slave_write_no_retry(struct bif_slave_dev *sdev, u16 addr,
+ u8 *buf, int len)
+{
+ struct bif_ctrl_dev *bdev = sdev->bdev;
+ int rc = 0;
+ int i;
+
+ rc = bif_select_slave(sdev);
+ if (rc)
+ return rc;
+
+ if (bdev->desc->ops->write_slave_registers) {
+ /*
+ * Use low level slave register write implementation in order to
+ * receive the benefits of BIF burst writes.
+ */
+ rc = bdev->desc->ops->write_slave_registers(bdev, addr, buf,
+ len);
+ if (rc)
+ pr_err("write_slave_registers failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_ERA, addr >> 8);
+ if (rc)
+ goto out;
+
+ rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_WRA, addr & 0xFF);
+ if (rc)
+ goto out;
+
+ for (i = 0; i < len; i++) {
+ rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_WD,
+ buf[i]);
+ if (rc)
+ goto out;
+ }
+
+ return 0;
+out:
+ pr_err("bus_transaction failed, rc=%d\n", rc);
+ return rc;
+}
+
+/*
+ * Write to a specified number of consecutive registers. Retry the transaction
+ * several times in case of communcation failures.
+ */
+static int _bif_slave_write(struct bif_slave_dev *sdev, u16 addr, u8 *buf,
+ int len)
+{
+ int rc = -EPERM;
+ int i;
+
+ for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+ rc = _bif_slave_write_no_retry(sdev, addr, buf, len);
+ if (rc == 0)
+ break;
+ /* Force slave reselection. */
+ sdev->bdev->selected_sdev = NULL;
+ }
+
+ return rc;
+}
+
+/* Takes a mutex if this consumer is not an exclusive bus user. */
+static void bif_ctrl_lock(struct bif_ctrl *ctrl)
+{
+ if (!ctrl->exclusive_lock) {
+ mutex_lock(&ctrl->bdev->mutex);
+ bif_cancel_irq_mode_work(ctrl->bdev);
+ }
+}
+
+/* Releases a mutex if this consumer is not an exclusive bus user. */
+static void bif_ctrl_unlock(struct bif_ctrl *ctrl)
+{
+ if (!ctrl->exclusive_lock) {
+ bif_schedule_irq_mode_work(ctrl->bdev);
+ mutex_unlock(&ctrl->bdev->mutex);
+ }
+}
+
+static void bif_slave_ctrl_lock(struct bif_slave *slave)
+{
+ bif_ctrl_lock(&slave->ctrl);
+}
+
+static void bif_slave_ctrl_unlock(struct bif_slave *slave)
+{
+ bif_ctrl_unlock(&slave->ctrl);
+}
+
+static int bif_check_task(struct bif_slave *slave, unsigned int task)
+{
+ if (IS_ERR_OR_NULL(slave)) {
+ pr_err("Invalid slave handle.\n");
+ return -EINVAL;
+ } else if (!slave->sdev->bdev) {
+ pr_err("BIF controller has been removed.\n");
+ return -ENXIO;
+ } else if (!slave->sdev->slave_ctrl_function
+ || slave->sdev->slave_ctrl_function->task_count == 0) {
+ pr_err("BIF slave does not support slave control.\n");
+ return -ENODEV;
+ } else if (task >= slave->sdev->slave_ctrl_function->task_count) {
+ pr_err("Requested task: %u greater than max: %u for this slave\n",
+ task, slave->sdev->slave_ctrl_function->task_count);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * bif_request_irq() - request a BIF slave IRQ by slave task number
+ * @slave: BIF slave handle
+ * @task: BIF task number of the IRQ inside of the slave. This
+ * corresponds to the slave control channel specified for a given
+ * BIF function inside of the slave.
+ * @nb: Notifier block to call when the IRQ fires
+ *
+ * This function registers a notifier block to call when the BIF slave interrupt
+ * is triggered and also enables the interrupt. The interrupt is enabled inside
+ * of the BIF slave's slave control function and also the BIF bus is put into
+ * interrupt mode.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_request_irq(struct bif_slave *slave, unsigned int task,
+ struct notifier_block *nb)
+{
+ int rc;
+ u16 addr;
+ u8 reg, mask;
+
+ rc = bif_check_task(slave, task);
+ if (rc) {
+ pr_err("Invalid slave or task, rc=%d\n", rc);
+ return rc;
+ }
+
+ bif_slave_ctrl_lock(slave);
+
+ rc = blocking_notifier_chain_register(
+ &slave->sdev->slave_ctrl_function->irq_notifier_list[task], nb);
+ if (rc) {
+ pr_err("Notifier registration failed, rc=%d\n", rc);
+ goto done;
+ }
+
+ /* Enable the interrupt within the slave */
+ mask = BIT(task % SLAVE_CTRL_TASKS_PER_SET);
+ addr = SLAVE_CTRL_FUNC_IRQ_EN_ADDR(
+ slave->sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+ if (task / SLAVE_CTRL_TASKS_PER_SET == 0) {
+ /* Set global interrupt enable. */
+ mask |= BIT(0);
+ }
+ rc = _bif_slave_read(slave->sdev, addr, ®, 1);
+ if (rc) {
+ pr_err("BIF slave register read failed, rc=%d\n", rc);
+ goto notifier_unregister;
+ }
+ reg |= mask;
+ rc = _bif_slave_write(slave->sdev, addr, ®, 1);
+ if (rc) {
+ pr_err("BIF slave register write failed, rc=%d\n", rc);
+ goto notifier_unregister;
+ }
+
+ /* Set global interrupt enable if task not in set 0. */
+ if (task / SLAVE_CTRL_TASKS_PER_SET != 0) {
+ mask = BIT(0);
+ addr = SLAVE_CTRL_FUNC_IRQ_EN_ADDR(
+ slave->sdev->slave_ctrl_function->slave_ctrl_pointer, 0);
+ rc = _bif_slave_read(slave->sdev, addr, ®, 1);
+ if (rc) {
+ pr_err("BIF slave register read failed, rc=%d\n", rc);
+ goto notifier_unregister;
+ }
+ reg |= mask;
+ rc = _bif_slave_write(slave->sdev, addr, ®, 1);
+ if (rc) {
+ pr_err("BIF slave register write failed, rc=%d\n", rc);
+ goto notifier_unregister;
+ }
+ }
+
+ rc = slave->sdev->bdev->desc->ops->set_bus_state(slave->sdev->bdev,
+ BIF_BUS_STATE_INTERRUPT);
+ if (rc) {
+ pr_err("Could not set BIF bus to interrupt mode, rc=%d\n", rc);
+ goto notifier_unregister;
+ }
+
+ slave->sdev->bdev->irq_count++;
+done:
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+
+notifier_unregister:
+ blocking_notifier_chain_unregister(
+ &slave->sdev->slave_ctrl_function->irq_notifier_list[task],
+ nb);
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+
+}
+EXPORT_SYMBOL(bif_request_irq);
+
+/**
+ * bif_free_irq() - free a BIF slave IRQ by slave task number
+ * @slave: BIF slave handle
+ * @task: BIF task number of the IRQ inside of the slave. This
+ * corresponds to the slave control channel specified for a given
+ * BIF function inside of the slave.
+ * @nb: Notifier block previously registered with this interrupt
+ *
+ * This function unregisters a notifier block that was previously registered
+ * with bif_request_irq().
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_free_irq(struct bif_slave *slave, unsigned int task,
+ struct notifier_block *nb)
+{
+ int rc;
+ u16 addr;
+ u8 reg;
+
+ rc = bif_check_task(slave, task);
+ if (rc) {
+ pr_err("Invalid slave or task, rc=%d\n", rc);
+ return rc;
+ }
+
+ bif_slave_ctrl_lock(slave);
+
+ /* Disable the interrupt within the slave */
+ reg = BIT(task % SLAVE_CTRL_TASKS_PER_SET);
+ addr = SLAVE_CTRL_FUNC_IRQ_CLEAR_ADDR(
+ slave->sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+ rc = _bif_slave_write(slave->sdev, addr, ®, 1);
+ if (rc) {
+ pr_err("BIF slave register write failed, rc=%d\n", rc);
+ goto done;
+ }
+
+ rc = blocking_notifier_chain_unregister(
+ &slave->sdev->slave_ctrl_function->irq_notifier_list[task], nb);
+ if (rc) {
+ pr_err("Notifier unregistration failed, rc=%d\n", rc);
+ goto done;
+ }
+
+ slave->sdev->bdev->irq_count--;
+
+ if (slave->sdev->bdev->irq_count == 0) {
+ bif_cancel_irq_mode_work(slave->sdev->bdev);
+ } else if (slave->sdev->bdev->irq_count < 0) {
+ pr_err("Unbalanced IRQ free.\n");
+ rc = -EINVAL;
+ slave->sdev->bdev->irq_count = 0;
+ }
+done:
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_free_irq);
+
+/**
+ * bif_trigger_task() - trigger a task within a BIF slave
+ * @slave: BIF slave handle
+ * @task: BIF task inside of the slave to trigger. This corresponds to
+ * the slave control channel specified for a given BIF function
+ * inside of the slave.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_trigger_task(struct bif_slave *slave, unsigned int task)
+{
+ int rc;
+ u16 addr;
+ u8 reg;
+
+ rc = bif_check_task(slave, task);
+ if (rc) {
+ pr_err("Invalid slave or task, rc=%d\n", rc);
+ return rc;
+ }
+
+ bif_slave_ctrl_lock(slave);
+
+ /* Trigger the task within the slave. */
+ reg = BIT(task % SLAVE_CTRL_TASKS_PER_SET);
+ addr = SLAVE_CTRL_FUNC_TASK_TRIGGER_ADDR(
+ slave->sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+ rc = _bif_slave_write(slave->sdev, addr, ®, 1);
+ if (rc) {
+ pr_err("BIF slave register write failed, rc=%d\n", rc);
+ goto done;
+ }
+
+done:
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_trigger_task);
+
+/**
+ * bif_task_is_busy() - checks the state of a BIF slave task
+ * @slave: BIF slave handle
+ * @task: BIF task inside of the slave to trigger. This corresponds to
+ * the slave control channel specified for a given BIF function
+ * inside of the slave.
+ *
+ * Returns 1 if the task is busy, 0 if it is not busy, and errno on error.
+ */
+int bif_task_is_busy(struct bif_slave *slave, unsigned int task)
+{
+ int rc;
+ u16 addr;
+ u8 reg;
+
+ rc = bif_check_task(slave, task);
+ if (rc) {
+ pr_err("Invalid slave or task, rc=%d\n", rc);
+ return rc;
+ }
+
+ bif_slave_ctrl_lock(slave);
+
+ /* Check the task busy state. */
+ addr = SLAVE_CTRL_FUNC_TASK_BUSY_ADDR(
+ slave->sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+ rc = _bif_slave_read(slave->sdev, addr, ®, 1);
+ if (rc) {
+ pr_err("BIF slave register read failed, rc=%d\n", rc);
+ goto done;
+ }
+
+ rc = (reg & BIT(task % SLAVE_CTRL_TASKS_PER_SET)) ? 1 : 0;
+done:
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_task_is_busy);
+
+static int bif_slave_notify_irqs(struct bif_slave_dev *sdev, int set, u8 val)
+{
+ int rc = 0;
+ int i, task;
+
+ for (i = 0; i < SLAVE_CTRL_TASKS_PER_SET; i++) {
+ if (val & (1 << i)) {
+ task = set * SLAVE_CTRL_TASKS_PER_SET + i;
+
+ rc = blocking_notifier_call_chain(
+ &sdev->slave_ctrl_function->irq_notifier_list[task],
+ task, sdev->bdev);
+ rc = notifier_to_errno(rc);
+ if (rc)
+ pr_err("Notification failed for task %d\n",
+ task);
+ }
+ }
+
+ return rc;
+}
+
+static int bif_slave_handle_irq(struct bif_slave_dev *sdev)
+{
+ struct bif_ctrl_dev *bdev = sdev->bdev;
+ bool resp = false;
+ int rc = 0;
+ int i;
+ u16 addr;
+ u8 reg;
+
+ mutex_lock(&sdev->bdev->mutex);
+ bif_cancel_irq_mode_work(sdev->bdev);
+
+ rc = bif_select_slave(sdev);
+ if (rc) {
+ pr_err("Could not select slave, rc=%d\n", rc);
+ goto done;
+ }
+
+ /* Check overall slave interrupt status. */
+ rc = bdev->desc->ops->bus_transaction_query(bdev, BIF_TRANS_BC,
+ BIF_CMD_ISTS, &resp);
+ if (rc) {
+ pr_err("Could not query slave interrupt status, rc=%d\n", rc);
+ goto done;
+ }
+
+ if (resp) {
+ for (i = 0; i < sdev->slave_ctrl_function->task_count
+ / SLAVE_CTRL_TASKS_PER_SET; i++) {
+ addr = sdev->slave_ctrl_function->slave_ctrl_pointer
+ + 4 * i + 1;
+ rc = _bif_slave_read(sdev, addr, ®, 1);
+ if (rc) {
+ pr_err("BIF slave register read failed, rc=%d\n",
+ rc);
+ goto done;
+ }
+
+ /* Ensure that interrupts are pending in the set. */
+ if (reg != 0x00) {
+ /*
+ * Release mutex before notifying consumers so
+ * that they can use the bus.
+ */
+ mutex_unlock(&sdev->bdev->mutex);
+ rc = bif_slave_notify_irqs(sdev, i, reg);
+ if (rc) {
+ pr_err("BIF slave irq notification failed, rc=%d\n",
+ rc);
+ goto notification_failed;
+ }
+ mutex_lock(&sdev->bdev->mutex);
+
+ rc = bif_select_slave(sdev);
+ if (rc) {
+ pr_err("Could not select slave, rc=%d\n",
+ rc);
+ goto done;
+ }
+
+ /* Clear all interrupts in this set. */
+ rc = _bif_slave_write(sdev, addr, ®, 1);
+ if (rc) {
+ pr_err("BIF slave register write failed, rc=%d\n",
+ rc);
+ goto done;
+ }
+ }
+ }
+ }
+
+done:
+ bif_schedule_irq_mode_work(sdev->bdev);
+ mutex_unlock(&sdev->bdev->mutex);
+notification_failed:
+ if (rc == 0)
+ rc = resp;
+ return rc;
+}
+
+/**
+ * bif_ctrl_notify_slave_irq() - notify the BIF framework that a slave interrupt
+ * was received by a BIF controller
+ * @bdev: BIF controller device pointer
+ *
+ * This function should only be called from a BIF controller driver.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_ctrl_notify_slave_irq(struct bif_ctrl_dev *bdev)
+{
+ struct bif_slave_dev *sdev;
+ int rc = 0, handled = 0;
+
+ if (IS_ERR_OR_NULL(bdev))
+ return -EINVAL;
+
+ mutex_lock(&bif_sdev_list_mutex);
+
+ list_for_each_entry(sdev, &bif_sdev_list, list) {
+ if (sdev->bdev == bdev && sdev->present) {
+ rc = bif_slave_handle_irq(sdev);
+ if (rc < 0) {
+ pr_err("Could not handle BIF slave irq, rc=%d\n",
+ rc);
+ break;
+ }
+ handled += rc;
+ }
+ }
+
+ mutex_unlock(&bif_sdev_list_mutex);
+
+ if (handled == 0)
+ pr_info("Spurious BIF slave interrupt detected.\n");
+
+ if (rc > 0)
+ rc = 0;
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_notify_slave_irq);
+
+/**
+ * bif_ctrl_notify_battery_changed() - notify the BIF framework that a battery
+ * pack has been inserted or removed
+ * @bdev: BIF controller device pointer
+ *
+ * This function should only be called from a BIF controller driver.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_ctrl_notify_battery_changed(struct bif_ctrl_dev *bdev)
+{
+ int rc = 0;
+ int present;
+
+ if (IS_ERR_OR_NULL(bdev))
+ return -EINVAL;
+
+ if (bdev->desc->ops->get_battery_presence) {
+ present = bdev->desc->ops->get_battery_presence(bdev);
+ if (present < 0) {
+ pr_err("Could not determine battery presence, rc=%d\n",
+ rc);
+ return rc;
+ }
+
+ if (bdev->battery_present == !!present)
+ return 0;
+
+ bdev->battery_present = present;
+
+ rc = blocking_notifier_call_chain(&bdev->bus_change_notifier,
+ present ? BIF_BUS_EVENT_BATTERY_INSERTED
+ : BIF_BUS_EVENT_BATTERY_REMOVED, bdev);
+ if (rc)
+ pr_err("Call chain noification failed, rc=%d\n", rc);
+ }
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_notify_battery_changed);
+
+/**
+ * bif_ctrl_signal_battery_changed() - notify the BIF framework that a battery
+ * pack has been inserted or removed
+ * @ctrl: BIF controller consumer handle
+ *
+ * This function should only be called by a BIF consumer driver on systems where
+ * the BIF controller driver is unable to determine when a battery is inserted
+ * or removed.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_ctrl_signal_battery_changed(struct bif_ctrl *ctrl)
+{
+ if (IS_ERR_OR_NULL(ctrl))
+ return -EINVAL;
+
+ return bif_ctrl_notify_battery_changed(ctrl->bdev);
+}
+EXPORT_SYMBOL(bif_ctrl_signal_battery_changed);
+
+/**
+ * bif_ctrl_notifier_register() - register a notifier block to be called when
+ * a battery pack is inserted or removed
+ * @ctrl: BIF controller consumer handle
+ *
+ * The value passed into the notifier when it is called is one of
+ * enum bif_bus_event.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_ctrl_notifier_register(struct bif_ctrl *ctrl, struct notifier_block *nb)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(ctrl))
+ return -EINVAL;
+
+ rc = blocking_notifier_chain_register(&ctrl->bdev->bus_change_notifier,
+ nb);
+ if (rc)
+ pr_err("Notifier registration failed, rc=%d\n", rc);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_notifier_register);
+
+/**
+ * bif_ctrl_notifier_unregister() - unregister a battery status change notifier
+ * block that was previously registered
+ * @ctrl: BIF controller consumer handle
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_ctrl_notifier_unregister(struct bif_ctrl *ctrl,
+ struct notifier_block *nb)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(ctrl))
+ return -EINVAL;
+
+ rc =
+ blocking_notifier_chain_unregister(&ctrl->bdev->bus_change_notifier,
+ nb);
+ if (rc)
+ pr_err("Notifier unregistration failed, rc=%d\n", rc);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_notifier_unregister);
+
+/**
+ * bif_get_bus_handle() - returns the BIF controller consumer handle associated
+ * with a BIF slave handle
+ * @slave: BIF slave handle
+ *
+ * Note, bif_ctrl_put() should never be called for the pointer output by
+ * bif_get_bus_handle().
+ */
+struct bif_ctrl *bif_get_bus_handle(struct bif_slave *slave)
+{
+ if (IS_ERR_OR_NULL(slave))
+ return ERR_PTR(-EINVAL);
+
+ return &slave->ctrl;
+}
+EXPORT_SYMBOL(bif_get_bus_handle);
+
+/**
+ * bif_ctrl_count() - returns the number of registered BIF controllers
+ */
+int bif_ctrl_count(void)
+{
+ struct bif_ctrl_dev *bdev;
+ int count = 0;
+
+ mutex_lock(&bif_ctrl_list_mutex);
+
+ list_for_each_entry(bdev, &bif_ctrl_list, list) {
+ count++;
+ }
+ mutex_unlock(&bif_ctrl_list_mutex);
+
+ return count;
+}
+EXPORT_SYMBOL(bif_ctrl_count);
+
+/**
+ * bif_ctrl_get_by_id() - get a handle for the id'th BIF controller registered
+ * in the system
+ * @id: Arbitrary number associated with the BIF bus in the system
+ *
+ * id must be in the range [0, bif_ctrl_count() - 1]. This function should only
+ * need to be called by a BIF consumer that is unable to link to a given BIF
+ * controller via a device tree binding.
+ *
+ * Returns a BIF controller consumer handle if successful or an ERR_PTR if not.
+ */
+struct bif_ctrl *bif_ctrl_get_by_id(unsigned int id)
+{
+ struct bif_ctrl_dev *bdev;
+ struct bif_ctrl_dev *bdev_found = NULL;
+ struct bif_ctrl *ctrl = ERR_PTR(-ENODEV);
+
+ mutex_lock(&bif_ctrl_list_mutex);
+
+ list_for_each_entry(bdev, &bif_ctrl_list, list) {
+ if (id == 0) {
+ bdev_found = bdev;
+ break;
+ }
+ id--;
+ }
+ mutex_unlock(&bif_ctrl_list_mutex);
+
+ if (bdev_found) {
+ ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
+ if (!ctrl) {
+ pr_err("Bus handle allocation failed\n");
+ ctrl = ERR_PTR(-ENOMEM);
+ } else {
+ ctrl->bdev = bdev_found;
+ }
+ }
+
+ return ctrl;
+}
+EXPORT_SYMBOL(bif_ctrl_get_by_id);
+
+/**
+ * bif_ctrl_get() - get a handle for the BIF controller that is linked to the
+ * consumer device in the device tree
+ * @consumer_dev: Pointer to the consumer's device
+ *
+ * In order to use this function, the BIF consumer's device must specify the
+ * "qcom,bif-ctrl" property in its device tree node which points to a BIF
+ * controller device node.
+ *
+ * Returns a BIF controller consumer handle if successful or an ERR_PTR if not.
+ * If the BIF controller linked to the consumer device has not yet probed, then
+ * ERR_PTR(-EPROBE_DEFER) is returned.
+ */
+struct bif_ctrl *bif_ctrl_get(struct device *consumer_dev)
+{
+ struct device_node *ctrl_node = NULL;
+ struct bif_ctrl_dev *bdev_found = NULL;
+ struct bif_ctrl *ctrl = ERR_PTR(-EPROBE_DEFER);
+ struct bif_ctrl_dev *bdev = NULL;
+
+ if (!consumer_dev || !consumer_dev->of_node) {
+ pr_err("Invalid device node\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ ctrl_node = of_parse_phandle(consumer_dev->of_node, "qcom,bif-ctrl", 0);
+ if (!ctrl_node) {
+ pr_err("Could not find qcom,bif-ctrl property in %s\n",
+ consumer_dev->of_node->full_name);
+ return ERR_PTR(-ENXIO);
+ }
+
+ mutex_lock(&bif_ctrl_list_mutex);
+ list_for_each_entry(bdev, &bif_ctrl_list, list) {
+ if (bdev->ctrl_dev && bdev->ctrl_dev->of_node == ctrl_node) {
+ bdev_found = bdev;
+ break;
+ }
+ }
+ mutex_unlock(&bif_ctrl_list_mutex);
+
+ if (bdev_found) {
+ ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
+ if (!ctrl) {
+ pr_err("Bus handle allocation failed\n");
+ ctrl = ERR_PTR(-ENOMEM);
+ } else {
+ ctrl->bdev = bdev_found;
+ }
+ }
+
+ return ctrl;
+}
+EXPORT_SYMBOL(bif_ctrl_get);
+
+/**
+ * bif_ctrl_put() - frees a BIF controller handle
+ * @ctrl: BIF controller consumer handle
+ */
+void bif_ctrl_put(struct bif_ctrl *ctrl)
+{
+ if (!IS_ERR_OR_NULL(ctrl) && ctrl->exclusive_lock)
+ mutex_unlock(&ctrl->bdev->mutex);
+ kfree(ctrl);
+}
+EXPORT_SYMBOL(bif_ctrl_put);
+
+/*
+ * Returns true if all parameters are matched, otherwise false.
+ * function_type and function_version mean that their exists some function in
+ * the slave which has the specified type and subtype. ctrl == NULL is treated
+ * as a wildcard.
+ */
+static bool bif_slave_match(const struct bif_ctrl *ctrl,
+ struct bif_slave_dev *sdev, const struct bif_match_criteria *criteria)
+{
+ int i, type, version;
+
+ if (ctrl && (ctrl->bdev != sdev->bdev))
+ return false;
+
+ if (!sdev->present
+ && (!(criteria->match_mask & BIF_MATCH_IGNORE_PRESENCE)
+ || ((criteria->match_mask & BIF_MATCH_IGNORE_PRESENCE)
+ && !criteria->ignore_presence)))
+ return false;
+
+ if ((criteria->match_mask & BIF_MATCH_MANUFACTURER_ID)
+ && sdev->l1_data.manufacturer_id != criteria->manufacturer_id)
+ return false;
+
+ if ((criteria->match_mask & BIF_MATCH_PRODUCT_ID)
+ && sdev->l1_data.product_id != criteria->product_id)
+ return false;
+
+ if (criteria->match_mask & BIF_MATCH_FUNCTION_TYPE) {
+ if (!sdev->function_directory)
+ return false;
+ for (i = 0; i < sdev->l1_data.length / 4; i++) {
+ type = sdev->function_directory[i].function_type;
+ version = sdev->function_directory[i].function_version;
+ if (type == criteria->function_type &&
+ (version == criteria->function_version
+ || !(criteria->match_mask
+ & BIF_MATCH_FUNCTION_VERSION)))
+ return true;
+ }
+ return false;
+ }
+
+ return true;
+}
+
+/**
+ * bif_slave_match_count() - returns the number of slaves associated with the
+ * specified BIF controller which fit the matching
+ * criteria
+ * @ctrl: BIF controller consumer handle
+ * @match_criteria: Matching criteria used to filter slaves
+ */
+int bif_slave_match_count(const struct bif_ctrl *ctrl,
+ const struct bif_match_criteria *match_criteria)
+{
+ struct bif_slave_dev *sdev;
+ int count = 0;
+
+ mutex_lock(&bif_sdev_list_mutex);
+
+ list_for_each_entry(sdev, &bif_sdev_list, list) {
+ if (bif_slave_match(ctrl, sdev, match_criteria))
+ count++;
+ }
+
+ mutex_unlock(&bif_sdev_list_mutex);
+
+ return count;
+}
+EXPORT_SYMBOL(bif_slave_match_count);
+
+/**
+ * bif_slave_match_get() - get a slave handle for the id'th slave associated
+ * with the specified BIF controller which fits the
+ * matching criteria
+ * @ctrl: BIF controller consumer handle
+ * @id: Index into the set of matching slaves
+ * @match_criteria: Matching criteria used to filter slaves
+ *
+ * id must be in the range [0, bif_slave_match_count(ctrl, match_criteria) - 1].
+ *
+ * Returns a BIF slave handle if successful or an ERR_PTR if not.
+ */
+struct bif_slave *bif_slave_match_get(const struct bif_ctrl *ctrl,
+ unsigned int id, const struct bif_match_criteria *match_criteria)
+{
+ struct bif_slave_dev *sdev;
+ struct bif_slave *slave = ERR_PTR(-ENODEV);
+ struct bif_slave_dev *sdev_found = NULL;
+ int count = 0;
+
+ mutex_lock(&bif_sdev_list_mutex);
+
+ list_for_each_entry(sdev, &bif_sdev_list, list) {
+ if (bif_slave_match(ctrl, sdev, match_criteria))
+ count++;
+ if (count == id + 1) {
+ sdev_found = sdev;
+ break;
+ }
+ }
+
+ mutex_unlock(&bif_sdev_list_mutex);
+
+ if (sdev_found) {
+ slave = kzalloc(sizeof(*slave), GFP_KERNEL);
+ if (!slave) {
+ pr_err("Slave allocation failed\n");
+ slave = ERR_PTR(-ENOMEM);
+ } else {
+ slave->sdev = sdev_found;
+ slave->ctrl.bdev = sdev_found->bdev;
+ }
+ }
+
+ return slave;
+}
+EXPORT_SYMBOL(bif_slave_match_get);
+
+/**
+ * bif_slave_put() - frees a BIF slave handle
+ * @slave: BIF slave handle
+ */
+void bif_slave_put(struct bif_slave *slave)
+{
+ if (!IS_ERR_OR_NULL(slave) && slave->ctrl.exclusive_lock)
+ mutex_unlock(&slave->sdev->bdev->mutex);
+ kfree(slave);
+}
+EXPORT_SYMBOL(bif_slave_put);
+
+/**
+ * bif_slave_find_function() - get the function pointer and version of a
+ * BIF function if it is present on the specified slave
+ * @slave: BIF slave handle
+ * @function: BIF function to search for inside of the slave
+ * @version: If the function is found, then 'version' is set to the
+ * version value of the function
+ * @function_pointer: If the function is found, then 'function_pointer' is set
+ * to the BIF slave address of the function
+ *
+ * Returns 0 for success or errno if an error occurred. If the function is not
+ * found in the slave, then -ENODEV is returned.
+ */
+int bif_slave_find_function(struct bif_slave *slave, u8 function, u8 *version,
+ u16 *function_pointer)
+{
+ int rc = -ENODEV;
+ struct bif_ddb_l2_data *func;
+ int i;
+
+ if (IS_ERR_OR_NULL(slave) || IS_ERR_OR_NULL(version)
+ || IS_ERR_OR_NULL(function_pointer)) {
+ pr_err("Invalid pointer input.\n");
+ return -EINVAL;
+ }
+
+ func = slave->sdev->function_directory;
+
+ for (i = 0; i < slave->sdev->l1_data.length / 4; i++) {
+ if (function == func[i].function_type) {
+ *version = func[i].function_version;
+ *function_pointer = func[i].function_pointer;
+ rc = 0;
+ break;
+ }
+ }
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_slave_find_function);
+
+/**
+ * bif_slave_read() - read contiguous memory values from a BIF slave
+ * @slave: BIF slave handle
+ * @addr: BIF slave address to begin reading at
+ * @buf: Buffer to fill with memory values
+ * @len: Number of byte to read
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_slave_read(struct bif_slave *slave, u16 addr, u8 *buf, int len)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(slave) || IS_ERR_OR_NULL(buf)) {
+ pr_err("Invalid pointer input.\n");
+ return -EINVAL;
+ }
+
+ bif_slave_ctrl_lock(slave);
+
+ rc = _bif_slave_read(slave->sdev, addr, buf, len);
+ if (rc)
+ pr_err("BIF slave read failed, rc=%d\n", rc);
+
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_slave_read);
+
+/**
+ * bif_slave_write() - write contiguous memory values to a BIF slave
+ * @slave: BIF slave handle
+ * @addr: BIF slave address to begin writing at
+ * @buf: Buffer containing values to write
+ * @len: Number of byte to write
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_slave_write(struct bif_slave *slave, u16 addr, u8 *buf, int len)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(slave) || IS_ERR_OR_NULL(buf)) {
+ pr_err("Invalid pointer input.\n");
+ return -EINVAL;
+ }
+
+ bif_slave_ctrl_lock(slave);
+
+ rc = _bif_slave_write(slave->sdev, addr, buf, len);
+ if (rc)
+ pr_err("BIF slave write failed, rc=%d\n", rc);
+
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_slave_write);
+
+/**
+ * bif_slave_is_present() - check if a slave is currently physically present
+ * in the system
+ * @slave: BIF slave handle
+ *
+ * Returns 1 if the slave is present, 0 if the slave is not present, or errno
+ * if an error occurred.
+ *
+ * This function can be used by BIF consumer drivers to check if their slave
+ * handles are still meaningful after battery reinsertion.
+ */
+int bif_slave_is_present(struct bif_slave *slave)
+{
+ if (IS_ERR_OR_NULL(slave)) {
+ pr_err("Invalid pointer input.\n");
+ return -EINVAL;
+ }
+
+ return slave->sdev->present;
+}
+EXPORT_SYMBOL(bif_slave_is_present);
+
+/**
+ * bif_slave_is_selected() - check if a slave is currently selected on the BIF
+ * bus
+ * @slave: BIF slave handle
+ *
+ * Returns 1 if the slave is selected, 0 if the slave is not selected, or errno
+ * if an error occurred.
+ *
+ * This function should not be required under normal circumstances since the
+ * bif-core framework ensures that slaves are always selected when needed.
+ * It would be most useful when used as a helper in conjunction with
+ * bif_ctrl_bus_lock() and the raw transaction functions.
+ */
+int bif_slave_is_selected(struct bif_slave *slave)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(slave)) {
+ pr_err("Invalid pointer input.\n");
+ return -EINVAL;
+ }
+
+ if (slave->sdev->bdev->selected_sdev != slave->sdev)
+ return false;
+
+ bif_slave_ctrl_lock(slave);
+ rc = bif_is_slave_selected(slave->sdev->bdev);
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_slave_is_selected);
+
+/**
+ * bif_slave_select() - select a slave on the BIF bus
+ * @slave: BIF slave handle
+ *
+ * Returns 0 on success or errno if an error occurred.
+ *
+ * This function should not be required under normal circumstances since the
+ * bif-core framework ensures that slaves are always selected when needed.
+ * It would be most useful when used as a helper in conjunction with
+ * bif_ctrl_bus_lock() and the raw transaction functions.
+ */
+int bif_slave_select(struct bif_slave *slave)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(slave)) {
+ pr_err("Invalid pointer input.\n");
+ return -EINVAL;
+ }
+
+ bif_slave_ctrl_lock(slave);
+ slave->sdev->bdev->selected_sdev = NULL;
+ rc = bif_select_slave(slave->sdev);
+ bif_slave_ctrl_unlock(slave);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_slave_select);
+
+/**
+ * bif_ctrl_raw_transaction() - perform a raw BIF transaction on the bus which
+ * expects no slave response
+ * @ctrl: BIF controller consumer handle
+ * @transaction: BIF transaction to carry out. This should be one of the
+ * values in enum bif_transaction.
+ * @data: 8-bit data to use in the transaction. The meaning of
+ * this data depends upon the transaction that is to be
+ * performed.
+ *
+ * When performing a bus command (BC) transaction, values in enum
+ * bif_bus_command may be used for the data parameter. Additional manufacturer
+ * specific values may also be used in a BC transaction.
+ *
+ * Returns 0 on success or errno if an error occurred.
+ *
+ * This function should only need to be used when BIF transactions are required
+ * that are not handled by the bif-core directly.
+ */
+int bif_ctrl_raw_transaction(struct bif_ctrl *ctrl, int transaction, u8 data)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(ctrl)) {
+ pr_err("Invalid pointer input.\n");
+ return -EINVAL;
+ }
+
+ bif_ctrl_lock(ctrl);
+
+ rc = ctrl->bdev->desc->ops->bus_transaction(ctrl->bdev, transaction,
+ data);
+ if (rc)
+ pr_err("BIF bus transaction failed, rc=%d\n", rc);
+
+ bif_ctrl_unlock(ctrl);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_raw_transaction);
+
+/**
+ * bif_ctrl_raw_transaction_read() - perform a raw BIF transaction on the bus
+ * which expects an RD or TACK slave response word
+ * @ctrl: BIF controller consumer handle
+ * @transaction: BIF transaction to carry out. This should be one of the
+ * values in enum bif_transaction.
+ * @data: 8-bit data to use in the transaction. The meaning of
+ * this data depends upon the transaction that is to be
+ * performed.
+ * @response: Pointer to an integer which is filled with the 11-bit
+ * slave response word upon success. The 11-bit format is
+ * (MSB to LSB) BCF, ACK, EOT, D7-D0.
+ *
+ * When performing a bus command (BC) transaction, values in enum
+ * bif_bus_command may be used for the data parameter. Additional manufacturer
+ * specific values may also be used in a BC transaction.
+ *
+ * Returns 0 on success or errno if an error occurred.
+ *
+ * This function should only need to be used when BIF transactions are required
+ * that are not handled by the bif-core directly.
+ */
+int bif_ctrl_raw_transaction_read(struct bif_ctrl *ctrl, int transaction,
+ u8 data, int *response)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(ctrl) || IS_ERR_OR_NULL(response)) {
+ pr_err("Invalid pointer input.\n");
+ return -EINVAL;
+ }
+
+ bif_ctrl_lock(ctrl);
+
+ rc = ctrl->bdev->desc->ops->bus_transaction_read(ctrl->bdev,
+ transaction, data, response);
+ if (rc)
+ pr_err("BIF bus transaction failed, rc=%d\n", rc);
+
+ bif_ctrl_unlock(ctrl);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_raw_transaction_read);
+
+/**
+ * bif_ctrl_raw_transaction_query() - perform a raw BIF transaction on the bus
+ * which expects a BQ slave response
+ * @ctrl: BIF controller consumer handle
+ * @transaction: BIF transaction to carry out. This should be one of the
+ * values in enum bif_transaction.
+ * @data: 8-bit data to use in the transaction. The meaning of
+ * this data depends upon the transaction that is to be
+ * performed.
+ * @query_response: Pointer to boolean which is set to true if a BQ pulse
+ * is receieved, or false if no BQ pulse is received before
+ * timing out.
+ *
+ * When performing a bus command (BC) transaction, values in enum
+ * bif_bus_command may be used for the data parameter. Additional manufacturer
+ * specific values may also be used in a BC transaction.
+ *
+ * Returns 0 on success or errno if an error occurred.
+ *
+ * This function should only need to be used when BIF transactions are required
+ * that are not handled by the bif-core directly.
+ */
+int bif_ctrl_raw_transaction_query(struct bif_ctrl *ctrl, int transaction,
+ u8 data, bool *query_response)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(ctrl) || IS_ERR_OR_NULL(query_response)) {
+ pr_err("Invalid pointer input.\n");
+ return -EINVAL;
+ }
+
+ bif_ctrl_lock(ctrl);
+
+ rc = ctrl->bdev->desc->ops->bus_transaction_query(ctrl->bdev,
+ transaction, data, query_response);
+ if (rc)
+ pr_err("BIF bus transaction failed, rc=%d\n", rc);
+
+ bif_ctrl_unlock(ctrl);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_raw_transaction_query);
+
+/**
+ * bif_ctrl_bus_lock() - lock the BIF bus of a controller for exclusive access
+ * @ctrl: BIF controller consumer handle
+ *
+ * This function should only need to be called in circumstances where a BIF
+ * consumer is issuing special BIF bus commands that have strict ordering
+ * requirements.
+ */
+void bif_ctrl_bus_lock(struct bif_ctrl *ctrl)
+{
+ if (IS_ERR_OR_NULL(ctrl)) {
+ pr_err("Invalid controller handle.\n");
+ return;
+ }
+
+ if (ctrl->exclusive_lock) {
+ pr_err("BIF bus exclusive lock already held\n");
+ return;
+ }
+
+ mutex_lock(&ctrl->bdev->mutex);
+ ctrl->exclusive_lock = true;
+ bif_cancel_irq_mode_work(ctrl->bdev);
+}
+EXPORT_SYMBOL(bif_ctrl_bus_lock);
+
+/**
+ * bif_ctrl_bus_unlock() - lock the BIF bus of a controller that was previously
+ * locked for exclusive access
+ * @ctrl: BIF controller consumer handle
+ *
+ * This function must only be called after first calling bif_ctrl_bus_lock().
+ */
+void bif_ctrl_bus_unlock(struct bif_ctrl *ctrl)
+{
+ if (IS_ERR_OR_NULL(ctrl)) {
+ pr_err("Invalid controller handle.\n");
+ return;
+ }
+
+ if (!ctrl->exclusive_lock) {
+ pr_err("BIF bus exclusive lock not already held\n");
+ return;
+ }
+
+ ctrl->exclusive_lock = false;
+ bif_schedule_irq_mode_work(ctrl->bdev);
+ mutex_unlock(&ctrl->bdev->mutex);
+}
+EXPORT_SYMBOL(bif_ctrl_bus_unlock);
+
+/**
+ * bif_ctrl_measure_rid() - measure the battery pack Rid pull-down resistance
+ * in ohms
+ * @ctrl: BIF controller consumer handle
+ *
+ * Returns the resistance of the Rid resistor in ohms if successful or errno
+ * if an error occurred.
+ */
+int bif_ctrl_measure_rid(struct bif_ctrl *ctrl)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(ctrl)) {
+ pr_err("Invalid controller handle.\n");
+ return -ENODEV;
+ }
+
+ if (!ctrl->bdev->desc->ops->get_battery_rid) {
+ pr_err("Cannot measure Rid.\n");
+ return -ENXIO;
+ }
+
+ bif_ctrl_lock(ctrl);
+
+ rc = ctrl->bdev->desc->ops->get_battery_rid(ctrl->bdev);
+ if (rc < 0)
+ pr_err("Error during Rid measurement, rc=%d\n", rc);
+
+ bif_ctrl_unlock(ctrl);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_measure_rid);
+
+/**
+ * bif_ctrl_get_bus_period() - get the BIF bus period (tau_bif) in nanoseconds
+ * @ctrl: BIF controller consumer handle
+ *
+ * Returns the currently configured bus period in nanoseconds if successful or
+ * errno if an error occurred.
+ */
+int bif_ctrl_get_bus_period(struct bif_ctrl *ctrl)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(ctrl)) {
+ pr_err("Invalid controller handle.\n");
+ return -ENODEV;
+ }
+
+ if (!ctrl->bdev->desc->ops->get_bus_period) {
+ pr_err("Cannot get the BIF bus period.\n");
+ return -ENXIO;
+ }
+
+ rc = ctrl->bdev->desc->ops->get_bus_period(ctrl->bdev);
+ if (rc < 0)
+ pr_err("Error during bus period retrieval, rc=%d\n", rc);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_get_bus_period);
+
+/**
+ * bif_ctrl_set_bus_period() - set the BIF bus period (tau_bif) in nanoseconds
+ * @ctrl: BIF controller consumer handle
+ * @period_ns: BIF bus period in nanoseconds to use
+ *
+ * If the exact period is not supported by the BIF controller hardware, then the
+ * next larger supported period will be used.
+ *
+ * Returns 0 on success or errno if an error occurred.
+ */
+int bif_ctrl_set_bus_period(struct bif_ctrl *ctrl, int period_ns)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(ctrl)) {
+ pr_err("Invalid controller handle.\n");
+ return -ENODEV;
+ }
+
+ if (!ctrl->bdev->desc->ops->set_bus_period) {
+ pr_err("Cannot set the BIF bus period.\n");
+ return -ENXIO;
+ }
+
+ bif_ctrl_lock(ctrl);
+ rc = ctrl->bdev->desc->ops->set_bus_period(ctrl->bdev, period_ns);
+ if (rc)
+ pr_err("Error during bus period configuration, rc=%d\n", rc);
+ bif_ctrl_unlock(ctrl);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_set_bus_period);
+
+/**
+ * bif_ctrl_get_bus_state() - get the current state of the BIF bus
+ * @ctrl: BIF controller consumer handle
+ *
+ * Returns a bus state from enum bif_bus_state if successful or errno if an
+ * error occurred.
+ */
+int bif_ctrl_get_bus_state(struct bif_ctrl *ctrl)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(ctrl)) {
+ pr_err("Invalid controller handle.\n");
+ return -ENODEV;
+ }
+
+ rc = ctrl->bdev->desc->ops->get_bus_state(ctrl->bdev);
+ if (rc < 0)
+ pr_err("Error during bus state retrieval, rc=%d\n", rc);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_get_bus_state);
+
+/**
+ * bif_ctrl_set_bus_state() - set the state of the BIF bus
+ * @ctrl: BIF controller consumer handle
+ * @state: State for the BIF bus to enter
+ *
+ * Returns 0 on success or errno if an error occurred.
+ */
+int bif_ctrl_set_bus_state(struct bif_ctrl *ctrl, enum bif_bus_state state)
+{
+ int rc;
+
+ if (IS_ERR_OR_NULL(ctrl)) {
+ pr_err("Invalid controller handle.\n");
+ return -ENODEV;
+ }
+
+ bif_ctrl_lock(ctrl);
+
+ rc = ctrl->bdev->desc->ops->set_bus_state(ctrl->bdev, state);
+ if (rc < 0)
+ pr_err("Error during bus state configuration, rc=%d\n", rc);
+
+ /*
+ * Uncache the selected slave if the new bus state results in the slave
+ * becoming unselected.
+ */
+ if (state == BIF_BUS_STATE_MASTER_DISABLED
+ || state == BIF_BUS_STATE_POWER_DOWN
+ || state == BIF_BUS_STATE_STANDBY)
+ ctrl->bdev->selected_sdev = NULL;
+
+ bif_ctrl_unlock(ctrl);
+
+ return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_set_bus_state);
+
+/*
+ * Check if the specified function is a protocol function and if it is, then
+ * instantiate protocol function data for the slave.
+ */
+static int bif_initialize_protocol_function(struct bif_slave_dev *sdev,
+ struct bif_ddb_l2_data *func)
+{
+ int rc = 0;
+ u8 buf[4];
+
+ /* Ensure that this is a protocol function. */
+ if (func->function_type != BIF_FUNC_PROTOCOL)
+ return 0;
+
+ if (sdev->protocol_function) {
+ pr_err("Duplicate protocol function found for BIF slave; DEV_ADR=0x%02X\n",
+ sdev->slave_addr);
+ return -EPERM;
+ }
+
+ sdev->protocol_function = kzalloc(sizeof(struct bif_protocol_function),
+ GFP_KERNEL);
+ if (!sdev->protocol_function) {
+ pr_err("out of memory\n");
+ return -ENOMEM;
+ }
+
+ rc = _bif_slave_read(sdev, func->function_pointer, buf, 4);
+ if (rc) {
+ pr_err("Protocol function data read failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ sdev->protocol_function->protocol_pointer = buf[0] << 8 | buf[1];
+ sdev->protocol_function->device_id_pointer = buf[2] << 8 | buf[3];
+ sdev->protocol_function->l2_entry = func;
+
+ rc = _bif_slave_read(sdev, sdev->protocol_function->device_id_pointer,
+ sdev->protocol_function->device_id, BIF_DEVICE_ID_BYTE_LENGTH);
+ if (rc) {
+ pr_err("Device ID read failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ /* Check if this slave does not have a UID value stored. */
+ if (sdev->unique_id_bits_known == 0) {
+ sdev->unique_id_bits_known = BIF_UNIQUE_ID_BIT_LENGTH;
+ /* Fill in UID using manufacturer ID and device ID. */
+ sdev->unique_id[0] = sdev->l1_data.manufacturer_id >> 8;
+ sdev->unique_id[1] = sdev->l1_data.manufacturer_id;
+ memcpy(&sdev->unique_id[2],
+ sdev->protocol_function->device_id,
+ BIF_DEVICE_ID_BYTE_LENGTH);
+ }
+
+ return rc;
+}
+
+/*
+ * Check if the specified function is a slave control function and if it is,
+ * then instantiate slave control function data for the slave.
+ */
+static int bif_initialize_slave_control_function(struct bif_slave_dev *sdev,
+ struct bif_ddb_l2_data *func)
+{
+ int rc = 0;
+ int i;
+ u8 buf[3];
+
+ /* Ensure that this is a slave control function. */
+ if (func->function_type != BIF_FUNC_SLAVE_CONTROL)
+ return 0;
+
+ if (sdev->slave_ctrl_function) {
+ pr_err("Duplicate slave control function found for BIF slave; DEV_ADR=0x%02X\n",
+ sdev->slave_addr);
+ return -EPERM;
+ }
+
+ sdev->slave_ctrl_function
+ = kzalloc(sizeof(struct bif_protocol_function), GFP_KERNEL);
+ if (!sdev->slave_ctrl_function) {
+ pr_err("out of memory\n");
+ return -ENOMEM;
+ }
+
+ rc = _bif_slave_read(sdev, func->function_pointer, buf, 3);
+ if (rc) {
+ pr_err("Slave control function data read failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ sdev->slave_ctrl_function->slave_ctrl_pointer = buf[0] << 8 | buf[1];
+ sdev->slave_ctrl_function->task_count
+ = buf[2] * SLAVE_CTRL_TASKS_PER_SET;
+ sdev->slave_ctrl_function->l2_entry = func;
+
+ if (sdev->slave_ctrl_function->task_count > 0) {
+ sdev->slave_ctrl_function->irq_notifier_list =
+ kzalloc(sizeof(struct blocking_notifier_head)
+ * sdev->slave_ctrl_function->task_count,
+ GFP_KERNEL);
+ if (!sdev->slave_ctrl_function->irq_notifier_list) {
+ pr_err("out of memory\n");
+ kfree(sdev->slave_ctrl_function);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < sdev->slave_ctrl_function->task_count; i++) {
+ BLOCKING_INIT_NOTIFIER_HEAD(
+ &sdev->slave_ctrl_function->irq_notifier_list[i]);
+ }
+ }
+
+ return rc;
+}
+
+/**
+ * bif_crc_ccitt() - calculate the CRC-CCITT CRC value of the data specified
+ * @buffer: Data to calculate the CRC of
+ * @len: Length of the data buffer in bytes
+ *
+ * MIPI-BIF specifies the usage of CRC-CCITT for BIF data objects. This
+ * function performs the CRC calculation while taking into account the bit
+ * ordering used by BIF.
+ */
+u16 bif_crc_ccitt(const u8 *buffer, unsigned int len)
+{
+ u16 crc = 0xFFFF;
+
+ while (len--) {
+ crc = crc_ccitt_byte(crc, bitrev8(*buffer));
+ buffer++;
+ }
+ return bitrev16(crc);
+}
+EXPORT_SYMBOL(bif_crc_ccitt);
+
+static u16 bif_object_crc_ccitt(const struct bif_object *object)
+{
+ u16 crc = 0xFFFF;
+ int i;
+
+ crc = crc_ccitt_byte(crc, bitrev8(object->type));
+ crc = crc_ccitt_byte(crc, bitrev8(object->version));
+ crc = crc_ccitt_byte(crc, bitrev8(object->manufacturer_id >> 8));
+ crc = crc_ccitt_byte(crc, bitrev8(object->manufacturer_id));
+ crc = crc_ccitt_byte(crc, bitrev8(object->length >> 8));
+ crc = crc_ccitt_byte(crc, bitrev8(object->length));
+
+ for (i = 0; i < object->length - 8; i++)
+ crc = crc_ccitt_byte(crc, bitrev8(object->data[i]));
+
+ return bitrev16(crc);
+}
+
+/*
+ * Check if the specified function is an NVM function and if it is, then
+ * instantiate NVM function data for the slave and read all objects.
+ */
+static int bif_initialize_nvm_function(struct bif_slave_dev *sdev,
+ struct bif_ddb_l2_data *func)
+{
+ int rc = 0;
+ int data_len;
+ u8 buf[8], object_type;
+ struct bif_object *object;
+ struct bif_object *temp;
+ u16 addr;
+ u16 crc;
+
+ /* Ensure that this is an NVM function. */
+ if (func->function_type != BIF_FUNC_NVM)
+ return 0;
+
+ if (sdev->nvm_function) {
+ pr_err("Duplicate NVM function found for BIF slave; DEV_ADR=0x%02X\n",
+ sdev->slave_addr);
+ return -EPERM;
+ }
+
+ sdev->nvm_function
+ = kzalloc(sizeof(*sdev->nvm_function), GFP_KERNEL);
+ if (!sdev->nvm_function) {
+ pr_err("out of memory\n");
+ return -ENOMEM;
+ }
+
+ rc = _bif_slave_read(sdev, func->function_pointer, buf, 8);
+ if (rc) {
+ pr_err("NVM function data read failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ sdev->nvm_function->nvm_pointer = buf[0] << 8 | buf[1];
+ sdev->nvm_function->slave_control_channel = buf[2];
+ sdev->nvm_function->write_buffer_size = buf[3];
+ sdev->nvm_function->nvm_base_address = buf[4] << 8 | buf[5];
+ sdev->nvm_function->nvm_size = buf[6] << 8 | buf[7];
+
+ INIT_LIST_HEAD(&sdev->nvm_function->object_list);
+
+ /* Read object list */
+ addr = sdev->nvm_function->nvm_base_address;
+ rc = _bif_slave_read(sdev, addr, &object_type, 1);
+ if (rc) {
+ pr_err("Slave memory read failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ /* Object type == 0x00 corresponds to the end of the object list. */
+ while (object_type != 0x00) {
+ object = kzalloc(sizeof(*object), GFP_KERNEL);
+ if (!object) {
+ pr_err("out of memory\n");
+ rc = -ENOMEM;
+ goto free_data;
+ }
+ list_add_tail(&object->list, &sdev->nvm_function->object_list);
+
+ rc = _bif_slave_read(sdev, addr + 1, buf + 1, 5);
+ if (rc) {
+ pr_err("Slave memory read of object header failed; addr=0x%04X, len=%d, rc=%d\n",
+ addr + 1, 5, rc);
+ goto free_data;
+ }
+
+ object->addr = addr;
+ object->type = object_type;
+ object->version = buf[1];
+ object->manufacturer_id = buf[2] << 8 | buf[3];
+ object->length = buf[4] << 8 | buf[5];
+
+ if ((object->addr + object->length)
+ > (sdev->nvm_function->nvm_base_address
+ + sdev->nvm_function->nvm_size)) {
+ pr_warn("warning: BIF slave object is not formatted correctly; NVM base=0x%04X, NVM len=%d, object addr=0x%04X, object len=%d\n",
+ sdev->nvm_function->nvm_base_address,
+ sdev->nvm_function->nvm_size,
+ object->addr,
+ object->length);
+ /* Limit object size to remaining NVM size. */
+ object->length = sdev->nvm_function->nvm_size
+ + sdev->nvm_function->nvm_base_address
+ - object->addr;
+ }
+
+ /* Object header + CRC takes up 8 bytes. */
+ data_len = object->length - 8;
+ object->data = kmalloc(data_len, GFP_KERNEL);
+ if (!object->data) {
+ pr_err("out of memory\n");
+ rc = -ENOMEM;
+ goto free_data;
+ }
+
+ rc = _bif_slave_read(sdev, addr + 6, object->data, data_len);
+ if (rc) {
+ pr_err("Slave memory read of object data failed; addr=0x%04X, len=%d, rc=%d\n",
+ addr + 6, data_len, rc);
+ goto free_data;
+ }
+
+ rc = _bif_slave_read(sdev, addr + 6 + data_len, buf, 3);
+ if (rc) {
+ pr_err("Slave memory read of object CRC failed; addr=0x%04X, len=%d, rc=%d\n",
+ addr + 6 + data_len, 3, rc);
+ goto free_data;
+ }
+
+ object->crc = buf[0] << 8 | buf[1];
+ object_type = buf[2];
+ sdev->nvm_function->object_count++;
+
+ crc = bif_object_crc_ccitt(object);
+ if (crc != object->crc)
+ pr_info("BIF object at addr=0x%04X has invalid CRC; crc calc=0x%04X, crc exp=0x%04X\n",
+ object->addr, crc, object->crc);
+
+ addr += object->length;
+ }
+
+ return rc;
+
+free_data:
+ list_for_each_entry_safe(object, temp,
+ &sdev->nvm_function->object_list, list) {
+ list_del(&object->list);
+ kfree(object->data);
+ kfree(object);
+ }
+ kfree(sdev->nvm_function);
+ sdev->nvm_function = NULL;
+ return rc;
+}
+
+static int bif_parse_slave_data(struct bif_slave_dev *sdev)
+{
+ int rc = 0;
+ u8 buf[10];
+ u8 *func_buf;
+ struct bif_ddb_l2_data *func;
+ int function_count, i;
+
+ rc = _bif_slave_read(sdev, BIF_DDB_L1_BASE_ADDR, buf, 10);
+ if (rc) {
+ pr_err("DDB L1 data read failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ sdev->l1_data.revision = buf[0];
+ sdev->l1_data.level = buf[1];
+ sdev->l1_data.device_class = buf[2] << 8 | buf[3];
+ sdev->l1_data.manufacturer_id = buf[4] << 8 | buf[5];
+ sdev->l1_data.product_id = buf[6] << 8 | buf[7];
+ sdev->l1_data.length = buf[8] << 8 | buf[9];
+
+ function_count = sdev->l1_data.length / 4;
+ if (sdev->l1_data.length % 4) {
+ pr_err("Function directory length=%d is invalid\n",
+ sdev->l1_data.length);
+ return -EPROTO;
+ }
+
+ /* No DDB L2 function directory */
+ if (function_count == 0)
+ return 0;
+
+ func_buf = kmalloc(sdev->l1_data.length, GFP_KERNEL);
+ if (!func_buf) {
+ pr_err("out of memory\n");
+ return -ENOMEM;
+ }
+
+ sdev->function_directory = kzalloc(
+ function_count * sizeof(struct bif_ddb_l2_data), GFP_KERNEL);
+ if (!sdev->function_directory) {
+ pr_err("out of memory\n");
+ return -ENOMEM;
+ }
+
+ rc = _bif_slave_read(sdev, BIF_DDB_L2_BASE_ADDR, func_buf,
+ sdev->l1_data.length);
+ if (rc) {
+ pr_err("DDB L2 data read failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ for (i = 0; i < function_count; i++) {
+ func = &sdev->function_directory[i];
+ func->function_type = func_buf[i * 4];
+ func->function_version = func_buf[i * 4 + 1];
+ func->function_pointer = func_buf[i * 4 + 2] << 8
+ | func_buf[i * 4 + 3];
+ rc = bif_initialize_protocol_function(sdev, func);
+ if (rc)
+ goto done;
+ rc = bif_initialize_slave_control_function(sdev, func);
+ if (rc)
+ goto done;
+ rc = bif_initialize_nvm_function(sdev, func);
+ if (rc)
+ goto done;
+ }
+done:
+ kfree(func_buf);
+ return rc;
+}
+
+static int bif_add_secondary_slaves(struct bif_slave_dev *primary_slave)
+{
+ int rc = 0;
+ int data_len, i;
+ u16 crc;
+ struct bif_slave_dev *sdev;
+ struct bif_object *object;
+
+ list_for_each_entry(object, &primary_slave->nvm_function->object_list,
+ list) {
+ if (object->type != BIF_OBJ_SEC_SLAVE)
+ continue;
+
+ data_len = object->length - 8;
+ if (data_len % BIF_UNIQUE_ID_BYTE_LENGTH) {
+ pr_info("Invalid secondary slave object found, addr=0x%04X, data len=%d\n",
+ object->addr, data_len);
+ continue;
+ }
+
+ crc = bif_object_crc_ccitt(object);
+ if (crc != object->crc) {
+ pr_info("BIF object at addr=0x%04X has invalid CRC; crc calc=0x%04X, crc exp=0x%04X\n",
+ object->addr, crc, object->crc);
+ continue;
+ }
+
+ for (i = 0; i < data_len / BIF_UNIQUE_ID_BYTE_LENGTH; i++) {
+ sdev = bif_add_slave(primary_slave->bdev);
+ if (IS_ERR(sdev)) {
+ rc = PTR_ERR(sdev);
+ pr_err("bif_add_slave failed, rc=%d\n", rc);
+ return rc;
+ }
+ memcpy(sdev->unique_id,
+ &object->data[i * BIF_UNIQUE_ID_BYTE_LENGTH],
+ BIF_UNIQUE_ID_BYTE_LENGTH);
+ sdev->unique_id_bits_known = BIF_UNIQUE_ID_BIT_LENGTH;
+
+ rc = bif_select_slave(sdev);
+ if (rc) {
+ pr_err("Could not select slave, rc=%d\n", rc);
+ goto free_slave;
+ }
+
+ rc = bif_is_slave_selected(sdev->bdev);
+ if (rc < 0) {
+ pr_err("Transaction failed, rc=%d\n", rc);
+ goto free_slave;
+ } else if (rc == 1) {
+ sdev->present = true;
+ sdev->bdev->selected_sdev = sdev;
+ } else {
+ sdev->present = false;
+ sdev->bdev->selected_sdev = NULL;
+ }
+ }
+ }
+
+ return rc;
+
+free_slave:
+ bif_remove_slave(sdev);
+ return rc;
+}
+
+/*
+ * Performs UID search to identify all slaves attached to the bus. Assumes that
+ * all necessary locks are held.
+ */
+static int bif_perform_uid_search(struct bif_ctrl_dev *bdev)
+{
+ struct bif_slave_dev *sdev;
+ struct bif_slave_dev *new_slave;
+ bool resp[2], resp_dilc;
+ int i;
+ int rc = 0;
+ u8 cmd_probe[2] = {BIF_CMD_DIP0, BIF_CMD_DIP1};
+ u8 cmd_enter[2] = {BIF_CMD_DIE0, BIF_CMD_DIE1};
+
+ /*
+ * Iterate over all partially known UIDs adding new ones as they are
+ * found.
+ */
+ list_for_each_entry(sdev, &bif_sdev_list, list) {
+ /* Skip slaves with fully known UIDs. */
+ if (sdev->unique_id_bits_known == BIF_UNIQUE_ID_BIT_LENGTH
+ || sdev->bdev != bdev)
+ continue;
+
+ /* Begin a new UID search. */
+ rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_BC,
+ BIF_CMD_DISS);
+ if (rc) {
+ pr_err("bus_transaction failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ /* Step through all known UID bits (MSB to LSB). */
+ for (i = 0; i < sdev->unique_id_bits_known; i++) {
+ rc = bdev->desc->ops->bus_transaction(bdev,
+ BIF_TRANS_BC,
+ cmd_enter[get_uid_bit(sdev->unique_id, i)]);
+ if (rc) {
+ pr_err("bus_transaction failed, rc=%d\n", rc);
+ return rc;
+ }
+ }
+
+ /* Step through unknown UID bits. */
+ for (i = sdev->unique_id_bits_known;
+ i < BIF_UNIQUE_ID_BIT_LENGTH; i++) {
+ rc = bdev->desc->ops->bus_transaction_query(bdev,
+ BIF_TRANS_BC, cmd_probe[0], &resp[0]);
+ if (rc) {
+ pr_err("bus_transaction failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ rc = bdev->desc->ops->bus_transaction_query(bdev,
+ BIF_TRANS_BC, cmd_probe[1], &resp[1]);
+ if (rc) {
+ pr_err("bus_transaction failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ if (resp[0] && resp[1]) {
+ /* Create an entry for the new UID branch. */
+ new_slave = bif_add_slave(bdev);
+ if (IS_ERR(new_slave)) {
+ rc = PTR_ERR(sdev);
+ pr_err("bif_add_slave failed, rc=%d\n",
+ rc);
+ return rc;
+ }
+ memcpy(new_slave->unique_id, sdev->unique_id,
+ BIF_UNIQUE_ID_BYTE_LENGTH);
+ new_slave->bdev = sdev->bdev;
+
+ set_uid_bit(sdev->unique_id, i, 0);
+ sdev->unique_id_bits_known = i + 1;
+
+ set_uid_bit(new_slave->unique_id, i, 1);
+ new_slave->unique_id_bits_known = i + 1;
+ } else if (resp[0]) {
+ set_uid_bit(sdev->unique_id, i, 0);
+ sdev->unique_id_bits_known = i + 1;
+ } else if (resp[1]) {
+ set_uid_bit(sdev->unique_id, i, 1);
+ sdev->unique_id_bits_known = i + 1;
+ } else {
+ pr_debug("no bus query response received\n");
+ rc = -ENXIO;
+ return rc;
+ }
+
+ rc = bdev->desc->ops->bus_transaction(bdev,
+ BIF_TRANS_BC, cmd_enter[resp[0] ? 0 : 1]);
+ if (rc) {
+ pr_err("bus_transaction failed, rc=%d\n", rc);
+ return rc;
+ }
+ }
+
+ rc = bdev->desc->ops->bus_transaction_query(bdev,
+ BIF_TRANS_BC, BIF_CMD_DILC, &resp_dilc);
+ if (rc) {
+ pr_err("bus_transaction failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ if (resp_dilc) {
+ sdev->present = true;
+ sdev->bdev->selected_sdev = sdev;
+ rc = bif_parse_slave_data(sdev);
+ } else {
+ pr_err("Slave failed to respond to DILC bus command; its UID is thus unverified.\n");
+ sdev->unique_id_bits_known = 0;
+ rc = -ENXIO;
+ return rc;
+ }
+ }
+
+ return rc;
+}
+
+/*
+ * Removes slaves from the bif_sdev_list which have the same UID as previous
+ * slaves in the list.
+ */
+static int bif_remove_duplicate_slaves(struct bif_ctrl_dev *bdev)
+{
+ struct bif_slave_dev *sdev;
+ struct bif_slave_dev *last_slave;
+ struct bif_slave_dev *temp;
+
+ list_for_each_entry_safe(last_slave, temp, &bif_sdev_list, list) {
+ list_for_each_entry(sdev, &bif_sdev_list, list) {
+ if (last_slave == sdev) {
+ break;
+ } else if (memcmp(last_slave->unique_id,
+ sdev->unique_id,
+ BIF_UNIQUE_ID_BYTE_LENGTH) == 0) {
+ bif_remove_slave(last_slave);
+ break;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static int bif_add_all_slaves(struct bif_ctrl_dev *bdev)
+{
+ struct bif_slave_dev *sdev;
+ int rc = 0;
+ int i;
+ bool has_slave = false, is_primary_slave = false;
+
+ mutex_lock(&bif_sdev_list_mutex);
+ mutex_lock(&bdev->mutex);
+
+ list_for_each_entry(sdev, &bif_sdev_list, list) {
+ if (sdev->bdev == bdev) {
+ has_slave = true;
+ break;
+ }
+ }
+
+ if (!has_slave) {
+ /* Create a single empty slave to start the search algorithm. */
+ sdev = bif_add_slave(bdev);
+ if (IS_ERR(sdev)) {
+ rc = PTR_ERR(sdev);
+ pr_err("bif_add_slave failed, rc=%d\n", rc);
+ goto out;
+ }
+
+ for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+ /* Attempt to select primary slave in battery pack. */
+ rc = bdev->desc->ops->bus_transaction(bdev,
+ BIF_TRANS_SDA, BIF_PRIMARY_SLAVE_DEV_ADR);
+ if (rc == 0)
+ break;
+ }
+ if (rc) {
+ pr_err("BIF bus_transaction failed, rc=%d\n", rc);
+ goto out;
+ }
+
+ /* Check if a slave is selected. */
+ rc = bif_is_slave_selected(bdev);
+ if (rc < 0) {
+ pr_err("BIF bus_transaction failed, rc=%d\n", rc);
+ goto out;
+ } else {
+ is_primary_slave = rc;
+ }
+ }
+
+ if (is_primary_slave) {
+ pr_debug("Using primary slave at DEV_ADR==0x%02X\n",
+ BIF_PRIMARY_SLAVE_DEV_ADR);
+ sdev->bdev->selected_sdev = sdev;
+ sdev->present = true;
+ sdev->slave_addr = BIF_PRIMARY_SLAVE_DEV_ADR;
+ rc = bif_parse_slave_data(sdev);
+ if (rc) {
+ pr_err("Failed to parse primary slave data, rc=%d\n",
+ rc);
+ goto out;
+ }
+ rc = bif_add_secondary_slaves(sdev);
+ if (rc) {
+ pr_err("Failed to add secondary slaves, rc=%d\n", rc);
+ goto out;
+ }
+ } else {
+ pr_debug("Falling back on full UID search.\n");
+ for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+ rc = bif_perform_uid_search(bdev);
+ if (rc == 0)
+ break;
+ }
+ if (rc) {
+ pr_debug("BIF UID search failed, rc=%d\n", rc);
+ goto out;
+ }
+ }
+
+ bif_remove_duplicate_slaves(bdev);
+
+ mutex_unlock(&bdev->mutex);
+ mutex_unlock(&bif_sdev_list_mutex);
+
+ return rc;
+
+out:
+ mutex_unlock(&bdev->mutex);
+ mutex_unlock(&bif_sdev_list_mutex);
+ pr_debug("BIF slave search failed, rc=%d\n", rc);
+ return rc;
+}
+
+static int bif_add_known_slave(struct bif_ctrl_dev *bdev, u8 slave_addr)
+{
+ struct bif_slave_dev *sdev;
+ int rc = 0;
+ int i;
+
+ for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+ /* Attempt to select the slave. */
+ rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_SDA,
+ slave_addr);
+ if (rc == 0)
+ break;
+ }
+ if (rc) {
+ pr_err("BIF bus_transaction failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ /* Check if a slave is selected. */
+ rc = bif_is_slave_selected(bdev);
+ if (rc < 0) {
+ pr_err("BIF bus_transaction failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ sdev = bif_add_slave(bdev);
+ if (IS_ERR(sdev)) {
+ rc = PTR_ERR(sdev);
+ pr_err("bif_add_slave failed, rc=%d\n", rc);
+ return rc;
+ }
+
+ sdev->bdev->selected_sdev = sdev;
+ sdev->present = true;
+ sdev->slave_addr = slave_addr;
+ rc = bif_parse_slave_data(sdev);
+ if (rc) {
+ pr_err("Failed to parse slave data, addr=0x%02X, rc=%d\n",
+ slave_addr, rc);
+ return rc;
+ }
+
+ return rc;
+}
+
+static int bif_add_known_slaves_from_dt(struct bif_ctrl_dev *bdev,
+ struct device_node *of_node)
+{
+ int len = 0;
+ int rc, i;
+ u32 addr;
+ const __be32 *val;
+
+ mutex_lock(&bif_sdev_list_mutex);
+ mutex_lock(&bdev->mutex);
+
+ val = of_get_property(of_node, "qcom,known-device-addresses", &len);
+ len /= sizeof(u32);
+ if (val && len == 0) {
+ pr_err("qcom,known-device-addresses property is invalid\n");
+ rc = -EINVAL;
+ goto out;
+ }
+
+ for (i = 0; i < len; i++) {
+ addr = be32_to_cpup(val++);
+ if (addr == 0x00 || addr > 0xFF) {
+ rc = -EINVAL;
+ pr_err("qcom,known-device-addresses property contains invalid address=0x%X\n",
+ addr);
+ goto out;
+ }
+ rc = bif_add_known_slave(bdev, addr);
+ if (rc) {
+ pr_err("bif_add_known_slave() failed, rc=%d\n", rc);
+ goto out;
+ }
+ }
+
+out:
+ if (len > 0)
+ bif_remove_duplicate_slaves(bdev);
+
+ mutex_unlock(&bdev->mutex);
+ mutex_unlock(&bif_sdev_list_mutex);
+
+ return rc;
+}
+
+/*
+ * Programs a device address for the specified slave in order to simplify
+ * slave selection in the future.
+ */
+static int bif_assign_slave_dev_addr(struct bif_slave_dev *sdev, u8 dev_addr)
+{
+ int rc;
+ u16 addr;
+
+ if (!sdev->protocol_function) {
+ pr_err("Protocol function not present; cannot set device address.\n");
+ return -ENODEV;
+ }
+
+ addr = PROTOCOL_FUNC_DEV_ADR_ADDR(
+ sdev->protocol_function->protocol_pointer);
+
+ rc = _bif_slave_write(sdev, addr, &dev_addr, 1);
+ if (rc)
+ pr_err("Failed to set slave device address.\n");
+ else
+ sdev->slave_addr = dev_addr;
+
+ return rc;
+}
+
+/* Assigns a unique device address to all slaves which do not have one. */
+static int bif_assign_all_slaves_dev_addr(struct bif_ctrl_dev *bdev)
+{
+ struct bif_slave_dev *sdev;
+ struct bif_slave_dev *sibling;
+ bool duplicate;
+ int rc = 0;
+ u8 dev_addr, first_dev_addr;
+
+ mutex_lock(&bif_sdev_list_mutex);
+ mutex_lock(&bdev->mutex);
+
+ first_dev_addr = next_dev_addr;
+ /*
+ * Iterate over all partially known UIDs adding new ones as they are
+ * found.
+ */
+ list_for_each_entry(sdev, &bif_sdev_list, list) {
+ /*
+ * Skip slaves without known UIDs, which already have a device
+ * address or which aren't present.
+ */
+ if (sdev->unique_id_bits_known != BIF_UNIQUE_ID_BIT_LENGTH
+ || sdev->slave_addr != 0x00 || !sdev->present)
+ continue;
+
+ do {
+ dev_addr = next_dev_addr;
+ duplicate = false;
+ list_for_each_entry(sibling, &bif_sdev_list, list) {
+ if (sibling->slave_addr == dev_addr) {
+ duplicate = true;
+ break;
+ }
+ }
+
+ next_dev_addr = dev_addr + 1;
+ } while (duplicate && (next_dev_addr != first_dev_addr));
+
+ if (next_dev_addr == first_dev_addr) {
+ pr_err("No more BIF slave device addresses available.\n");
+ rc = -ENODEV;
+ goto out;
+ }
+
+ rc = bif_assign_slave_dev_addr(sdev, dev_addr);
+ if (rc) {
+ pr_err("Failed to set slave address.\n");
+ goto out;
+ }
+ }
+
+ mutex_unlock(&bdev->mutex);
+ mutex_unlock(&bif_sdev_list_mutex);
+
+ return rc;
+
+out:
+ mutex_unlock(&bdev->mutex);
+ mutex_unlock(&bif_sdev_list_mutex);
+ pr_err("BIF slave device address setting failed, rc=%d\n", rc);
+ return rc;
+}
+
+/**
+ * bdev_get_drvdata() - get the private BIF controller driver data
+ * @bdev: BIF controller device pointer
+ */
+void *bdev_get_drvdata(struct bif_ctrl_dev *bdev)
+{
+ return bdev->driver_data;
+}
+EXPORT_SYMBOL(bdev_get_drvdata);
+
+static const char * const battery_label[] = {
+ "unknown",
+ "none",
+ "special 1",
+ "special 2",
+ "special 3",
+ "low cost",
+ "smart",
+};
+
+static const char *bif_get_battery_pack_type(int rid_ohm)
+{
+ const char *label = battery_label[0];
+
+ if (rid_ohm > BIF_BATT_RID_SMART_MAX)
+ label = battery_label[1];
+ else if (rid_ohm >= BIF_BATT_RID_SMART_MIN)
+ label = battery_label[6];
+ else if (rid_ohm >= BIF_BATT_RID_LOW_COST_MIN
+ && rid_ohm <= BIF_BATT_RID_LOW_COST_MAX)
+ label = battery_label[5];
+ else if (rid_ohm >= BIF_BATT_RID_SPECIAL3_MIN
+ && rid_ohm <= BIF_BATT_RID_SPECIAL3_MAX)
+ label = battery_label[4];
+ else if (rid_ohm >= BIF_BATT_RID_SPECIAL2_MIN
+ && rid_ohm <= BIF_BATT_RID_SPECIAL2_MAX)
+ label = battery_label[3];
+ else if (rid_ohm >= BIF_BATT_RID_SPECIAL1_MIN
+ && rid_ohm <= BIF_BATT_RID_SPECIAL1_MAX)
+ label = battery_label[2];
+
+ return label;
+}
+
+/**
+ * bif_ctrl_register() - register a BIF controller with the BIF framework
+ * @bif_desc: Pointer to BIF controller descriptor
+ * @dev: Device pointer of the BIF controller
+ * @driver_data: Private driver data to associate with the BIF controller
+ * @of_node Pointer to the device tree node of the BIF controller
+ *
+ * Returns a BIF controller device pointer for the controller if registration
+ * is successful or an ERR_PTR if an error occurred.
+ */
+struct bif_ctrl_dev *bif_ctrl_register(struct bif_ctrl_desc *bif_desc,
+ struct device *dev, void *driver_data, struct device_node *of_node)
+{
+ struct bif_ctrl_dev *bdev = ERR_PTR(-EINVAL);
+ struct bif_slave_dev *sdev;
+ bool battery_present = false;
+ int rc, rid_ohm;
+
+ if (!bif_desc) {
+ pr_err("Invalid bif_desc specified\n");
+ return bdev;
+ } else if (!bif_desc->name) {
+ pr_err("BIF name missing\n");
+ return bdev;
+ } else if (!bif_desc->ops) {
+ pr_err("BIF operations missing\n");
+ return bdev;
+ } else if (!bif_desc->ops->bus_transaction
+ || !bif_desc->ops->bus_transaction_query
+ || !bif_desc->ops->bus_transaction_read
+ || !bif_desc->ops->get_bus_state
+ || !bif_desc->ops->set_bus_state) {
+ pr_err("BIF operation callback function(s) missing\n");
+ return bdev;
+ }
+
+ bdev = kzalloc(sizeof(struct bif_ctrl_dev), GFP_KERNEL);
+ if (bdev == NULL) {
+ pr_err("Memory allocation failed for bif_ctrl_dev\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ mutex_init(&bdev->mutex);
+ INIT_LIST_HEAD(&bdev->list);
+ INIT_DELAYED_WORK(&bdev->enter_irq_mode_work, bif_enter_irq_mode_work);
+ bdev->desc = bif_desc;
+ bdev->ctrl_dev = dev;
+ bdev->driver_data = driver_data;
+ bdev->irq_mode_delay_jiffies = 2;
+
+ mutex_lock(&bif_ctrl_list_mutex);
+ list_add_tail(&bdev->list, &bif_ctrl_list);
+ mutex_unlock(&bif_ctrl_list_mutex);
+
+ rc = bif_add_all_slaves(bdev);
+ if (rc)
+ pr_debug("Search for all slaves failed, rc=%d\n", rc);
+ rc = bif_add_known_slaves_from_dt(bdev, of_node);
+ if (rc)
+ pr_err("Adding slaves based on device tree addressed failed, rc=%d.\n",
+ rc);
+ rc = bif_assign_all_slaves_dev_addr(bdev);
+ if (rc)
+ pr_err("Failed to set slave device address, rc=%d\n", rc);
+
+ bif_print_slaves();
+
+ if (bdev->desc->ops->get_battery_presence) {
+ rc = bdev->desc->ops->get_battery_presence(bdev);
+ if (rc < 0) {
+ pr_err("Could not determine battery presence, rc=%d\n",
+ rc);
+ } else {
+ battery_present = rc;
+ pr_info("Battery pack present = %c\n", rc ? 'Y' : 'N');
+ }
+ }
+
+ if (bdev->desc->ops->get_battery_rid) {
+ rid_ohm = bdev->desc->ops->get_battery_rid(bdev);
+ if (rid_ohm >= 0)
+ pr_info("Battery pack type = %s (Rid=%d ohm)\n",
+ bif_get_battery_pack_type(rid_ohm), rid_ohm);
+ else
+ pr_err("Could not read Rid, rc=%d\n", rid_ohm);
+ }
+
+ list_for_each_entry(sdev, &bif_sdev_list, list) {
+ if (sdev->present) {
+ battery_present = true;
+ break;
+ }
+ }
+
+ BLOCKING_INIT_NOTIFIER_HEAD(&bdev->bus_change_notifier);
+
+ if (battery_present) {
+ bdev->battery_present = true;
+ rc = blocking_notifier_call_chain(&bdev->bus_change_notifier,
+ BIF_BUS_EVENT_BATTERY_INSERTED, bdev);
+ if (rc)
+ pr_err("Call chain noification failed, rc=%d\n", rc);
+ }
+
+ return bdev;
+}
+EXPORT_SYMBOL(bif_ctrl_register);
+
+/**
+ * bif_ctrl_unregister() - unregisters a BIF controller
+ * @bdev: BIF controller device pointer
+ */
+void bif_ctrl_unregister(struct bif_ctrl_dev *bdev)
+{
+ if (bdev) {
+ mutex_lock(&bif_ctrl_list_mutex);
+ list_del(&bdev->list);
+ mutex_unlock(&bif_ctrl_list_mutex);
+ }
+}
+EXPORT_SYMBOL(bif_ctrl_unregister);