i2c: Adding support for Intel iSMT SMBus 2.0 host controller
The iSMT (Intel SMBus Message Transport) supports multi-master I2C/SMBus,
as well as IPMI. It's operation is DMA-based and utilizes descriptors to
initiate transactions on the bus.
The iSMT hardware can act as both a master and a target, although this
driver only supports being a master.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Bill Brown <bill.e.brown@intel.com>
Tested-by: Seth Heasley <seth.heasley@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c
new file mode 100644
index 0000000..3f7a9cb
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ismt.c
@@ -0,0 +1,963 @@
+/*
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Copyright(c) 2012 Intel Corporation. All rights reserved.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ * The full GNU General Public License is included in this distribution
+ * in the file called LICENSE.GPL.
+ *
+ * BSD LICENSE
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Supports the SMBus Message Transport (SMT) in the Intel Atom Processor
+ * S12xx Product Family.
+ *
+ * Features supported by this driver:
+ * Hardware PEC yes
+ * Block buffer yes
+ * Block process call transaction no
+ * Slave mode no
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/stddef.h>
+#include <linux/completion.h>
+#include <linux/dma-mapping.h>
+#include <linux/i2c.h>
+#include <linux/acpi.h>
+#include <linux/interrupt.h>
+
+#include <asm-generic/io-64-nonatomic-lo-hi.h>
+
+/* PCI Address Constants */
+#define SMBBAR 0
+
+/* PCI DIDs for the Intel SMBus Message Transport (SMT) Devices */
+#define PCI_DEVICE_ID_INTEL_S1200_SMT0 0x0c59
+#define PCI_DEVICE_ID_INTEL_S1200_SMT1 0x0c5a
+
+#define ISMT_DESC_ENTRIES 32 /* number of descriptor entries */
+#define ISMT_MAX_RETRIES 3 /* number of SMBus retries to attempt */
+
+/* Hardware Descriptor Constants - Control Field */
+#define ISMT_DESC_CWRL 0x01 /* Command/Write Length */
+#define ISMT_DESC_BLK 0X04 /* Perform Block Transaction */
+#define ISMT_DESC_FAIR 0x08 /* Set fairness flag upon successful arbit. */
+#define ISMT_DESC_PEC 0x10 /* Packet Error Code */
+#define ISMT_DESC_I2C 0x20 /* I2C Enable */
+#define ISMT_DESC_INT 0x40 /* Interrupt */
+#define ISMT_DESC_SOE 0x80 /* Stop On Error */
+
+/* Hardware Descriptor Constants - Status Field */
+#define ISMT_DESC_SCS 0x01 /* Success */
+#define ISMT_DESC_DLTO 0x04 /* Data Low Time Out */
+#define ISMT_DESC_NAK 0x08 /* NAK Received */
+#define ISMT_DESC_CRC 0x10 /* CRC Error */
+#define ISMT_DESC_CLTO 0x20 /* Clock Low Time Out */
+#define ISMT_DESC_COL 0x40 /* Collisions */
+#define ISMT_DESC_LPR 0x80 /* Large Packet Received */
+
+/* Macros */
+#define ISMT_DESC_ADDR_RW(addr, rw) (((addr) << 1) | (rw))
+
+/* iSMT General Register address offsets (SMBBAR + <addr>) */
+#define ISMT_GR_GCTRL 0x000 /* General Control */
+#define ISMT_GR_SMTICL 0x008 /* SMT Interrupt Cause Location */
+#define ISMT_GR_ERRINTMSK 0x010 /* Error Interrupt Mask */
+#define ISMT_GR_ERRAERMSK 0x014 /* Error AER Mask */
+#define ISMT_GR_ERRSTS 0x018 /* Error Status */
+#define ISMT_GR_ERRINFO 0x01c /* Error Information */
+
+/* iSMT Master Registers */
+#define ISMT_MSTR_MDBA 0x100 /* Master Descriptor Base Address */
+#define ISMT_MSTR_MCTRL 0x108 /* Master Control */
+#define ISMT_MSTR_MSTS 0x10c /* Master Status */
+#define ISMT_MSTR_MDS 0x110 /* Master Descriptor Size */
+#define ISMT_MSTR_RPOLICY 0x114 /* Retry Policy */
+
+/* iSMT Miscellaneous Registers */
+#define ISMT_SPGT 0x300 /* SMBus PHY Global Timing */
+
+/* General Control Register (GCTRL) bit definitions */
+#define ISMT_GCTRL_TRST 0x04 /* Target Reset */
+#define ISMT_GCTRL_KILL 0x08 /* Kill */
+#define ISMT_GCTRL_SRST 0x40 /* Soft Reset */
+
+/* Master Control Register (MCTRL) bit definitions */
+#define ISMT_MCTRL_SS 0x01 /* Start/Stop */
+#define ISMT_MCTRL_MEIE 0x10 /* Master Error Interrupt Enable */
+#define ISMT_MCTRL_FMHP 0x00ff0000 /* Firmware Master Head Ptr (FMHP) */
+
+/* Master Status Register (MSTS) bit definitions */
+#define ISMT_MSTS_HMTP 0xff0000 /* HW Master Tail Pointer (HMTP) */
+#define ISMT_MSTS_MIS 0x20 /* Master Interrupt Status (MIS) */
+#define ISMT_MSTS_MEIS 0x10 /* Master Error Int Status (MEIS) */
+#define ISMT_MSTS_IP 0x01 /* In Progress */
+
+/* Master Descriptor Size (MDS) bit definitions */
+#define ISMT_MDS_MASK 0xff /* Master Descriptor Size mask (MDS) */
+
+/* SMBus PHY Global Timing Register (SPGT) bit definitions */
+#define ISMT_SPGT_SPD_MASK 0xc0000000 /* SMBus Speed mask */
+#define ISMT_SPGT_SPD_80K 0x00 /* 80 kHz */
+#define ISMT_SPGT_SPD_100K (0x1 << 30) /* 100 kHz */
+#define ISMT_SPGT_SPD_400K (0x2 << 30) /* 400 kHz */
+#define ISMT_SPGT_SPD_1M (0x3 << 30) /* 1 MHz */
+
+
+/* MSI Control Register (MSICTL) bit definitions */
+#define ISMT_MSICTL_MSIE 0x01 /* MSI Enable */
+
+/* iSMT Hardware Descriptor */
+struct ismt_desc {
+ u8 tgtaddr_rw; /* target address & r/w bit */
+ u8 wr_len_cmd; /* write length in bytes or a command */
+ u8 rd_len; /* read length */
+ u8 control; /* control bits */
+ u8 status; /* status bits */
+ u8 retry; /* collision retry and retry count */
+ u8 rxbytes; /* received bytes */
+ u8 txbytes; /* transmitted bytes */
+ u32 dptr_low; /* lower 32 bit of the data pointer */
+ u32 dptr_high; /* upper 32 bit of the data pointer */
+} __packed;
+
+struct ismt_priv {
+ struct i2c_adapter adapter;
+ void *smba; /* PCI BAR */
+ struct pci_dev *pci_dev;
+ struct ismt_desc *hw; /* descriptor virt base addr */
+ dma_addr_t io_rng_dma; /* descriptor HW base addr */
+ u8 head; /* ring buffer head pointer */
+ struct completion cmp; /* interrupt completion */
+ u8 dma_buffer[I2C_SMBUS_BLOCK_MAX + 1]; /* temp R/W data buffer */
+ bool using_msi; /* type of interrupt flag */
+};
+
+/**
+ * ismt_ids - PCI device IDs supported by this driver
+ */
+static const DEFINE_PCI_DEVICE_TABLE(ismt_ids) = {
+ { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT0) },
+ { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_S1200_SMT1) },
+ { 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, ismt_ids);
+
+/* Bus speed control bits for slow debuggers - refer to the docs for usage */
+static unsigned int bus_speed;
+module_param(bus_speed, uint, S_IRUGO);
+MODULE_PARM_DESC(bus_speed, "Bus Speed in kHz (0 = BIOS default)");
+
+/**
+ * __ismt_desc_dump() - dump the contents of a specific descriptor
+ */
+static void __ismt_desc_dump(struct device *dev, const struct ismt_desc *desc)
+{
+
+ dev_dbg(dev, "Descriptor struct: %p\n", desc);
+ dev_dbg(dev, "\ttgtaddr_rw=0x%02X\n", desc->tgtaddr_rw);
+ dev_dbg(dev, "\twr_len_cmd=0x%02X\n", desc->wr_len_cmd);
+ dev_dbg(dev, "\trd_len= 0x%02X\n", desc->rd_len);
+ dev_dbg(dev, "\tcontrol= 0x%02X\n", desc->control);
+ dev_dbg(dev, "\tstatus= 0x%02X\n", desc->status);
+ dev_dbg(dev, "\tretry= 0x%02X\n", desc->retry);
+ dev_dbg(dev, "\trxbytes= 0x%02X\n", desc->rxbytes);
+ dev_dbg(dev, "\ttxbytes= 0x%02X\n", desc->txbytes);
+ dev_dbg(dev, "\tdptr_low= 0x%08X\n", desc->dptr_low);
+ dev_dbg(dev, "\tdptr_high= 0x%08X\n", desc->dptr_high);
+}
+/**
+ * ismt_desc_dump() - dump the contents of a descriptor for debug purposes
+ * @priv: iSMT private data
+ */
+static void ismt_desc_dump(struct ismt_priv *priv)
+{
+ struct device *dev = &priv->pci_dev->dev;
+ struct ismt_desc *desc = &priv->hw[priv->head];
+
+ dev_dbg(dev, "Dump of the descriptor struct: 0x%X\n", priv->head);
+ __ismt_desc_dump(dev, desc);
+}
+
+/**
+ * ismt_gen_reg_dump() - dump the iSMT General Registers
+ * @priv: iSMT private data
+ */
+static void ismt_gen_reg_dump(struct ismt_priv *priv)
+{
+ struct device *dev = &priv->pci_dev->dev;
+
+ dev_dbg(dev, "Dump of the iSMT General Registers\n");
+ dev_dbg(dev, " GCTRL.... : (0x%p)=0x%X\n",
+ priv->smba + ISMT_GR_GCTRL,
+ readl(priv->smba + ISMT_GR_GCTRL));
+ dev_dbg(dev, " SMTICL... : (0x%p)=0x%016llX\n",
+ priv->smba + ISMT_GR_SMTICL,
+ (long long unsigned int)readq(priv->smba + ISMT_GR_SMTICL));
+ dev_dbg(dev, " ERRINTMSK : (0x%p)=0x%X\n",
+ priv->smba + ISMT_GR_ERRINTMSK,
+ readl(priv->smba + ISMT_GR_ERRINTMSK));
+ dev_dbg(dev, " ERRAERMSK : (0x%p)=0x%X\n",
+ priv->smba + ISMT_GR_ERRAERMSK,
+ readl(priv->smba + ISMT_GR_ERRAERMSK));
+ dev_dbg(dev, " ERRSTS... : (0x%p)=0x%X\n",
+ priv->smba + ISMT_GR_ERRSTS,
+ readl(priv->smba + ISMT_GR_ERRSTS));
+ dev_dbg(dev, " ERRINFO.. : (0x%p)=0x%X\n",
+ priv->smba + ISMT_GR_ERRINFO,
+ readl(priv->smba + ISMT_GR_ERRINFO));
+}
+
+/**
+ * ismt_mstr_reg_dump() - dump the iSMT Master Registers
+ * @priv: iSMT private data
+ */
+static void ismt_mstr_reg_dump(struct ismt_priv *priv)
+{
+ struct device *dev = &priv->pci_dev->dev;
+
+ dev_dbg(dev, "Dump of the iSMT Master Registers\n");
+ dev_dbg(dev, " MDBA..... : (0x%p)=0x%016llX\n",
+ priv->smba + ISMT_MSTR_MDBA,
+ (long long unsigned int)readq(priv->smba + ISMT_MSTR_MDBA));
+ dev_dbg(dev, " MCTRL.... : (0x%p)=0x%X\n",
+ priv->smba + ISMT_MSTR_MCTRL,
+ readl(priv->smba + ISMT_MSTR_MCTRL));
+ dev_dbg(dev, " MSTS..... : (0x%p)=0x%X\n",
+ priv->smba + ISMT_MSTR_MSTS,
+ readl(priv->smba + ISMT_MSTR_MSTS));
+ dev_dbg(dev, " MDS...... : (0x%p)=0x%X\n",
+ priv->smba + ISMT_MSTR_MDS,
+ readl(priv->smba + ISMT_MSTR_MDS));
+ dev_dbg(dev, " RPOLICY.. : (0x%p)=0x%X\n",
+ priv->smba + ISMT_MSTR_RPOLICY,
+ readl(priv->smba + ISMT_MSTR_RPOLICY));
+ dev_dbg(dev, " SPGT..... : (0x%p)=0x%X\n",
+ priv->smba + ISMT_SPGT,
+ readl(priv->smba + ISMT_SPGT));
+}
+
+/**
+ * ismt_submit_desc() - add a descriptor to the ring
+ * @priv: iSMT private data
+ */
+static void ismt_submit_desc(struct ismt_priv *priv)
+{
+ uint fmhp;
+ uint val;
+
+ ismt_desc_dump(priv);
+ ismt_gen_reg_dump(priv);
+ ismt_mstr_reg_dump(priv);
+
+ /* Set the FMHP (Firmware Master Head Pointer)*/
+ fmhp = ((priv->head + 1) % ISMT_DESC_ENTRIES) << 16;
+ val = readl(priv->smba + ISMT_MSTR_MCTRL);
+ writel((val & ~ISMT_MCTRL_FMHP) | fmhp,
+ priv->smba + ISMT_MSTR_MCTRL);
+
+ /* Set the start bit */
+ val = readl(priv->smba + ISMT_MSTR_MCTRL);
+ writel(val | ISMT_MCTRL_SS,
+ priv->smba + ISMT_MSTR_MCTRL);
+}
+
+/**
+ * ismt_process_desc() - handle the completion of the descriptor
+ * @desc: the iSMT hardware descriptor
+ * @data: data buffer from the upper layer
+ * @priv: ismt_priv struct holding our dma buffer
+ * @size: SMBus transaction type
+ * @read_write: flag to indicate if this is a read or write
+ */
+static int ismt_process_desc(const struct ismt_desc *desc,
+ union i2c_smbus_data *data,
+ struct ismt_priv *priv, int size,
+ char read_write)
+{
+ u8 *dma_buffer = priv->dma_buffer;
+
+ dev_dbg(&priv->pci_dev->dev, "Processing completed descriptor\n");
+ __ismt_desc_dump(&priv->pci_dev->dev, desc);
+
+ if (desc->status & ISMT_DESC_SCS) {
+ if (read_write == I2C_SMBUS_WRITE &&
+ size != I2C_SMBUS_PROC_CALL)
+ return 0;
+
+ switch (size) {
+ case I2C_SMBUS_BYTE:
+ case I2C_SMBUS_BYTE_DATA:
+ data->byte = dma_buffer[0];
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ case I2C_SMBUS_PROC_CALL:
+ data->word = dma_buffer[0] | (dma_buffer[1] << 8);
+ break;
+ case I2C_SMBUS_BLOCK_DATA:
+ memcpy(&data->block[1], dma_buffer, desc->rxbytes);
+ data->block[0] = desc->rxbytes;
+ break;
+ }
+ return 0;
+ }
+
+ if (likely(desc->status & ISMT_DESC_NAK))
+ return -ENXIO;
+
+ if (desc->status & ISMT_DESC_CRC)
+ return -EBADMSG;
+
+ if (desc->status & ISMT_DESC_COL)
+ return -EAGAIN;
+
+ if (desc->status & ISMT_DESC_LPR)
+ return -EPROTO;
+
+ if (desc->status & (ISMT_DESC_DLTO | ISMT_DESC_CLTO))
+ return -ETIMEDOUT;
+
+ return -EIO;
+}
+
+/**
+ * ismt_access() - process an SMBus command
+ * @adap: the i2c host adapter
+ * @addr: address of the i2c/SMBus target
+ * @flags: command options
+ * @read_write: read from or write to device
+ * @command: the i2c/SMBus command to issue
+ * @size: SMBus transaction type
+ * @data: read/write data buffer
+ */
+static int ismt_access(struct i2c_adapter *adap, u16 addr,
+ unsigned short flags, char read_write, u8 command,
+ int size, union i2c_smbus_data *data)
+{
+ int ret;
+ dma_addr_t dma_addr = 0; /* address of the data buffer */
+ u8 dma_size = 0;
+ enum dma_data_direction dma_direction = 0;
+ struct ismt_desc *desc;
+ struct ismt_priv *priv = i2c_get_adapdata(adap);
+ struct device *dev = &priv->pci_dev->dev;
+
+ desc = &priv->hw[priv->head];
+
+ /* Initialize the descriptor */
+ memset(desc, 0, sizeof(struct ismt_desc));
+ desc->tgtaddr_rw = ISMT_DESC_ADDR_RW(addr, read_write);
+
+ /* Initialize common control bits */
+ if (likely(priv->using_msi))
+ desc->control = ISMT_DESC_INT | ISMT_DESC_FAIR;
+ else
+ desc->control = ISMT_DESC_FAIR;
+
+ if ((flags & I2C_CLIENT_PEC) && (size != I2C_SMBUS_QUICK)
+ && (size != I2C_SMBUS_I2C_BLOCK_DATA))
+ desc->control |= ISMT_DESC_PEC;
+
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ dev_dbg(dev, "I2C_SMBUS_QUICK\n");
+ break;
+
+ case I2C_SMBUS_BYTE:
+ if (read_write == I2C_SMBUS_WRITE) {
+ /*
+ * Send Byte
+ * The command field contains the write data
+ */
+ dev_dbg(dev, "I2C_SMBUS_BYTE: WRITE\n");
+ desc->control |= ISMT_DESC_CWRL;
+ desc->wr_len_cmd = command;
+ } else {
+ /* Receive Byte */
+ dev_dbg(dev, "I2C_SMBUS_BYTE: READ\n");
+ dma_size = 1;
+ dma_direction = DMA_FROM_DEVICE;
+ desc->rd_len = 1;
+ }
+ break;
+
+ case I2C_SMBUS_BYTE_DATA:
+ if (read_write == I2C_SMBUS_WRITE) {
+ /*
+ * Write Byte
+ * Command plus 1 data byte
+ */
+ dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: WRITE\n");
+ desc->wr_len_cmd = 2;
+ dma_size = 2;
+ dma_direction = DMA_TO_DEVICE;
+ priv->dma_buffer[0] = command;
+ priv->dma_buffer[1] = data->byte;
+ } else {
+ /* Read Byte */
+ dev_dbg(dev, "I2C_SMBUS_BYTE_DATA: READ\n");
+ desc->control |= ISMT_DESC_CWRL;
+ desc->wr_len_cmd = command;
+ desc->rd_len = 1;
+ dma_size = 1;
+ dma_direction = DMA_FROM_DEVICE;
+ }
+ break;
+
+ case I2C_SMBUS_WORD_DATA:
+ if (read_write == I2C_SMBUS_WRITE) {
+ /* Write Word */
+ dev_dbg(dev, "I2C_SMBUS_WORD_DATA: WRITE\n");
+ desc->wr_len_cmd = 3;
+ dma_size = 3;
+ dma_direction = DMA_TO_DEVICE;
+ priv->dma_buffer[0] = command;
+ priv->dma_buffer[1] = data->word & 0xff;
+ priv->dma_buffer[2] = data->word >> 8;
+ } else {
+ /* Read Word */
+ dev_dbg(dev, "I2C_SMBUS_WORD_DATA: READ\n");
+ desc->wr_len_cmd = command;
+ desc->control |= ISMT_DESC_CWRL;
+ desc->rd_len = 2;
+ dma_size = 2;
+ dma_direction = DMA_FROM_DEVICE;
+ }
+ break;
+
+ case I2C_SMBUS_PROC_CALL:
+ dev_dbg(dev, "I2C_SMBUS_PROC_CALL\n");
+ desc->wr_len_cmd = 3;
+ desc->rd_len = 2;
+ dma_size = 3;
+ dma_direction = DMA_BIDIRECTIONAL;
+ priv->dma_buffer[0] = command;
+ priv->dma_buffer[1] = data->word & 0xff;
+ priv->dma_buffer[2] = data->word >> 8;
+ break;
+
+ case I2C_SMBUS_BLOCK_DATA:
+ if (read_write == I2C_SMBUS_WRITE) {
+ /* Block Write */
+ dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: WRITE\n");
+ dma_size = data->block[0] + 1;
+ dma_direction = DMA_TO_DEVICE;
+ desc->wr_len_cmd = dma_size;
+ desc->control |= ISMT_DESC_BLK;
+ priv->dma_buffer[0] = command;
+ memcpy(&priv->dma_buffer[1], &data->block[1], dma_size);
+ } else {
+ /* Block Read */
+ dev_dbg(dev, "I2C_SMBUS_BLOCK_DATA: READ\n");
+ dma_size = I2C_SMBUS_BLOCK_MAX;
+ dma_direction = DMA_FROM_DEVICE;
+ desc->rd_len = dma_size;
+ desc->wr_len_cmd = command;
+ desc->control |= (ISMT_DESC_BLK | ISMT_DESC_CWRL);
+ }
+ break;
+
+ default:
+ dev_err(dev, "Unsupported transaction %d\n",
+ size);
+ return -EOPNOTSUPP;
+ }
+
+ /* map the data buffer */
+ if (dma_size != 0) {
+ dev_dbg(dev, " dev=%p\n", dev);
+ dev_dbg(dev, " data=%p\n", data);
+ dev_dbg(dev, " dma_buffer=%p\n", priv->dma_buffer);
+ dev_dbg(dev, " dma_size=%d\n", dma_size);
+ dev_dbg(dev, " dma_direction=%d\n", dma_direction);
+
+ dma_addr = dma_map_single(dev,
+ priv->dma_buffer,
+ dma_size,
+ dma_direction);
+
+ if (dma_mapping_error(dev, dma_addr)) {
+ dev_err(dev, "Error in mapping dma buffer %p\n",
+ priv->dma_buffer);
+ return -EIO;
+ }
+
+ dev_dbg(dev, " dma_addr = 0x%016llX\n",
+ dma_addr);
+
+ desc->dptr_low = lower_32_bits(dma_addr);
+ desc->dptr_high = upper_32_bits(dma_addr);
+ }
+
+ INIT_COMPLETION(priv->cmp);
+
+ /* Add the descriptor */
+ ismt_submit_desc(priv);
+
+ /* Now we wait for interrupt completion, 1s */
+ ret = wait_for_completion_timeout(&priv->cmp, HZ*1);
+
+ /* unmap the data buffer */
+ if (dma_size != 0)
+ dma_unmap_single(&adap->dev, dma_addr, dma_size, dma_direction);
+
+ if (unlikely(!ret)) {
+ dev_err(dev, "completion wait timed out\n");
+ ret = -ETIMEDOUT;
+ goto out;
+ }
+
+ /* do any post processing of the descriptor here */
+ ret = ismt_process_desc(desc, data, priv, size, read_write);
+
+out:
+ /* Update the ring pointer */
+ priv->head++;
+ priv->head %= ISMT_DESC_ENTRIES;
+
+ return ret;
+}
+
+/**
+ * ismt_func() - report which i2c commands are supported by this adapter
+ * @adap: the i2c host adapter
+ */
+static u32 ismt_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_SMBUS_QUICK |
+ I2C_FUNC_SMBUS_BYTE |
+ I2C_FUNC_SMBUS_BYTE_DATA |
+ I2C_FUNC_SMBUS_WORD_DATA |
+ I2C_FUNC_SMBUS_PROC_CALL |
+ I2C_FUNC_SMBUS_BLOCK_DATA |
+ I2C_FUNC_SMBUS_PEC;
+}
+
+/**
+ * smbus_algorithm - the adapter algorithm and supported functionality
+ * @smbus_xfer: the adapter algorithm
+ * @functionality: functionality supported by the adapter
+ */
+static const struct i2c_algorithm smbus_algorithm = {
+ .smbus_xfer = ismt_access,
+ .functionality = ismt_func,
+};
+
+/**
+ * ismt_handle_isr() - interrupt handler bottom half
+ * @priv: iSMT private data
+ */
+static irqreturn_t ismt_handle_isr(struct ismt_priv *priv)
+{
+ complete(&priv->cmp);
+
+ return IRQ_HANDLED;
+}
+
+
+/**
+ * ismt_do_interrupt() - IRQ interrupt handler
+ * @vec: interrupt vector
+ * @data: iSMT private data
+ */
+static irqreturn_t ismt_do_interrupt(int vec, void *data)
+{
+ u32 val;
+ struct ismt_priv *priv = data;
+
+ /*
+ * check to see it's our interrupt, return IRQ_NONE if not ours
+ * since we are sharing interrupt
+ */
+ val = readl(priv->smba + ISMT_MSTR_MSTS);
+
+ if (!(val & (ISMT_MSTS_MIS | ISMT_MSTS_MEIS)))
+ return IRQ_NONE;
+ else
+ writel(val | ISMT_MSTS_MIS | ISMT_MSTS_MEIS,
+ priv->smba + ISMT_MSTR_MSTS);
+
+ return ismt_handle_isr(priv);
+}
+
+/**
+ * ismt_do_msi_interrupt() - MSI interrupt handler
+ * @vec: interrupt vector
+ * @data: iSMT private data
+ */
+static irqreturn_t ismt_do_msi_interrupt(int vec, void *data)
+{
+ return ismt_handle_isr(data);
+}
+
+/**
+ * ismt_hw_init() - initialize the iSMT hardware
+ * @priv: iSMT private data
+ */
+static void ismt_hw_init(struct ismt_priv *priv)
+{
+ u32 val;
+ struct device *dev = &priv->pci_dev->dev;
+
+ /* initialize the Master Descriptor Base Address (MDBA) */
+ writeq(priv->io_rng_dma, priv->smba + ISMT_MSTR_MDBA);
+
+ /* initialize the Master Control Register (MCTRL) */
+ writel(ISMT_MCTRL_MEIE, priv->smba + ISMT_MSTR_MCTRL);
+
+ /* initialize the Master Status Register (MSTS) */
+ writel(0, priv->smba + ISMT_MSTR_MSTS);
+
+ /* initialize the Master Descriptor Size (MDS) */
+ val = readl(priv->smba + ISMT_MSTR_MDS);
+ writel((val & ~ISMT_MDS_MASK) | (ISMT_DESC_ENTRIES - 1),
+ priv->smba + ISMT_MSTR_MDS);
+
+ /*
+ * Set the SMBus speed (could use this for slow HW debuggers)
+ */
+
+ val = readl(priv->smba + ISMT_SPGT);
+
+ switch (bus_speed) {
+ case 0:
+ break;
+
+ case 80:
+ dev_dbg(dev, "Setting SMBus clock to 80 kHz\n");
+ writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_80K),
+ priv->smba + ISMT_SPGT);
+ break;
+
+ case 100:
+ dev_dbg(dev, "Setting SMBus clock to 100 kHz\n");
+ writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_100K),
+ priv->smba + ISMT_SPGT);
+ break;
+
+ case 400:
+ dev_dbg(dev, "Setting SMBus clock to 400 kHz\n");
+ writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_400K),
+ priv->smba + ISMT_SPGT);
+ break;
+
+ case 1000:
+ dev_dbg(dev, "Setting SMBus clock to 1000 kHz\n");
+ writel(((val & ~ISMT_SPGT_SPD_MASK) | ISMT_SPGT_SPD_1M),
+ priv->smba + ISMT_SPGT);
+ break;
+
+ default:
+ dev_warn(dev, "Invalid SMBus clock speed, only 0, 80, 100, 400, and 1000 are valid\n");
+ break;
+ }
+
+ val = readl(priv->smba + ISMT_SPGT);
+
+ switch (val & ISMT_SPGT_SPD_MASK) {
+ case ISMT_SPGT_SPD_80K:
+ bus_speed = 80;
+ break;
+ case ISMT_SPGT_SPD_100K:
+ bus_speed = 100;
+ break;
+ case ISMT_SPGT_SPD_400K:
+ bus_speed = 400;
+ break;
+ case ISMT_SPGT_SPD_1M:
+ bus_speed = 1000;
+ break;
+ }
+ dev_dbg(dev, "SMBus clock is running at %d kHz\n", bus_speed);
+}
+
+/**
+ * ismt_dev_init() - initialize the iSMT data structures
+ * @priv: iSMT private data
+ */
+static int ismt_dev_init(struct ismt_priv *priv)
+{
+ /* allocate memory for the descriptor */
+ priv->hw = dmam_alloc_coherent(&priv->pci_dev->dev,
+ (ISMT_DESC_ENTRIES
+ * sizeof(struct ismt_desc)),
+ &priv->io_rng_dma,
+ GFP_KERNEL);
+ if (!priv->hw)
+ return -ENOMEM;
+
+ memset(priv->hw, 0, (ISMT_DESC_ENTRIES * sizeof(struct ismt_desc)));
+
+ priv->head = 0;
+ init_completion(&priv->cmp);
+
+ return 0;
+}
+
+/**
+ * ismt_int_init() - initialize interrupts
+ * @priv: iSMT private data
+ */
+static int ismt_int_init(struct ismt_priv *priv)
+{
+ int err;
+
+ /* Try using MSI interrupts */
+ err = pci_enable_msi(priv->pci_dev);
+ if (err) {
+ dev_warn(&priv->pci_dev->dev,
+ "Unable to use MSI interrupts, falling back to legacy\n");
+ goto intx;
+ }
+
+ err = devm_request_irq(&priv->pci_dev->dev,
+ priv->pci_dev->irq,
+ ismt_do_msi_interrupt,
+ 0,
+ "ismt-msi",
+ priv);
+ if (err) {
+ pci_disable_msi(priv->pci_dev);
+ goto intx;
+ }
+
+ priv->using_msi = true;
+ goto done;
+
+ /* Try using legacy interrupts */
+intx:
+ err = devm_request_irq(&priv->pci_dev->dev,
+ priv->pci_dev->irq,
+ ismt_do_interrupt,
+ IRQF_SHARED,
+ "ismt-intx",
+ priv);
+ if (err) {
+ dev_err(&priv->pci_dev->dev, "no usable interrupts\n");
+ return -ENODEV;
+ }
+
+ priv->using_msi = false;
+
+done:
+ return 0;
+}
+
+static struct pci_driver ismt_driver;
+
+/**
+ * ismt_probe() - probe for iSMT devices
+ * @pdev: PCI-Express device
+ * @id: PCI-Express device ID
+ */
+static int
+ismt_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+ int err;
+ struct ismt_priv *priv;
+ unsigned long start, len;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ pci_set_drvdata(pdev, priv);
+ i2c_set_adapdata(&priv->adapter, priv);
+ priv->adapter.owner = THIS_MODULE;
+
+ priv->adapter.class = I2C_CLASS_HWMON;
+
+ priv->adapter.algo = &smbus_algorithm;
+
+ /* set up the sysfs linkage to our parent device */
+ priv->adapter.dev.parent = &pdev->dev;
+
+ /* number of retries on lost arbitration */
+ priv->adapter.retries = ISMT_MAX_RETRIES;
+
+ priv->pci_dev = pdev;
+
+ err = pcim_enable_device(pdev);
+ if (err) {
+ dev_err(&pdev->dev, "Failed to enable SMBus PCI device (%d)\n",
+ err);
+ return err;
+ }
+
+ /* enable bus mastering */
+ pci_set_master(pdev);
+
+ /* Determine the address of the SMBus area */
+ start = pci_resource_start(pdev, SMBBAR);
+ len = pci_resource_len(pdev, SMBBAR);
+ if (!start || !len) {
+ dev_err(&pdev->dev,
+ "SMBus base address uninitialized, upgrade BIOS\n");
+ return -ENODEV;
+ }
+
+ snprintf(priv->adapter.name, sizeof(priv->adapter.name),
+ "SMBus iSMT adapter at %lx", start);
+
+ dev_dbg(&priv->pci_dev->dev, " start=0x%lX\n", start);
+ dev_dbg(&priv->pci_dev->dev, " len=0x%lX\n", len);
+
+ err = acpi_check_resource_conflict(&pdev->resource[SMBBAR]);
+ if (err) {
+ dev_err(&pdev->dev, "ACPI resource conflict!\n");
+ return err;
+ }
+
+ err = pci_request_region(pdev, SMBBAR, ismt_driver.name);
+ if (err) {
+ dev_err(&pdev->dev,
+ "Failed to request SMBus region 0x%lx-0x%lx\n",
+ start, start + len);
+ return err;
+ }
+
+ priv->smba = pcim_iomap(pdev, SMBBAR, len);
+ if (!priv->smba) {
+ dev_err(&pdev->dev, "Unable to ioremap SMBus BAR\n");
+ err = -ENODEV;
+ goto fail;
+ }
+
+ if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(64)) != 0) ||
+ (pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)) != 0)) {
+ if ((pci_set_dma_mask(pdev, DMA_BIT_MASK(32)) != 0) ||
+ (pci_set_consistent_dma_mask(pdev,
+ DMA_BIT_MASK(32)) != 0)) {
+ dev_err(&pdev->dev, "pci_set_dma_mask fail %p\n",
+ pdev);
+ goto fail;
+ }
+ }
+
+ err = ismt_dev_init(priv);
+ if (err)
+ goto fail;
+
+ ismt_hw_init(priv);
+
+ err = ismt_int_init(priv);
+ if (err)
+ goto fail;
+
+ err = i2c_add_adapter(&priv->adapter);
+ if (err) {
+ dev_err(&pdev->dev, "Failed to add SMBus iSMT adapter\n");
+ err = -ENODEV;
+ goto fail;
+ }
+ return 0;
+
+fail:
+ pci_release_region(pdev, SMBBAR);
+ return err;
+}
+
+/**
+ * ismt_remove() - release driver resources
+ * @pdev: PCI-Express device
+ */
+static void ismt_remove(struct pci_dev *pdev)
+{
+ struct ismt_priv *priv = pci_get_drvdata(pdev);
+
+ i2c_del_adapter(&priv->adapter);
+ pci_release_region(pdev, SMBBAR);
+}
+
+/**
+ * ismt_suspend() - place the device in suspend
+ * @pdev: PCI-Express device
+ * @mesg: PM message
+ */
+#ifdef CONFIG_PM
+static int ismt_suspend(struct pci_dev *pdev, pm_message_t mesg)
+{
+ pci_save_state(pdev);
+ pci_set_power_state(pdev, pci_choose_state(pdev, mesg));
+ return 0;
+}
+
+/**
+ * ismt_resume() - PCI resume code
+ * @pdev: PCI-Express device
+ */
+static int ismt_resume(struct pci_dev *pdev)
+{
+ pci_set_power_state(pdev, PCI_D0);
+ pci_restore_state(pdev);
+ return pci_enable_device(pdev);
+}
+
+#else
+
+#define ismt_suspend NULL
+#define ismt_resume NULL
+
+#endif
+
+static struct pci_driver ismt_driver = {
+ .name = "ismt_smbus",
+ .id_table = ismt_ids,
+ .probe = ismt_probe,
+ .remove = ismt_remove,
+ .suspend = ismt_suspend,
+ .resume = ismt_resume,
+};
+
+module_pci_driver(ismt_driver);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Bill E. Brown <bill.e.brown@intel.com>");
+MODULE_DESCRIPTION("Intel SMBus Message Transport (iSMT) driver");