gpio: add MSIC gpio driver
Add gpio support for Intel MSIC chips found in Intel Medfield platforms.
MSIC supports totally 24 GPIOs with 16 low voltage and 8 high voltage pins.
Driver uses MSIC mfd interface for MSIC access.
(Updated comment to indicate why locking is actually safe)
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 8ee6d29..5169a99 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -520,4 +520,12 @@
help
Select this option to enable GPIO driver for the TPS65910
chip family.
+
+config GPIO_MSIC
+ bool "Intel MSIC mixed signal gpio support"
+ depends on MFD_INTEL_MSIC
+ help
+ Enable support for GPIO on intel MSIC controllers found in
+ intel MID devices
+
endif
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 1c2f6c0..7862f49 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -33,6 +33,7 @@
obj-$(CONFIG_GPIO_ML_IOH) += gpio-ml-ioh.o
obj-$(CONFIG_GPIO_MPC5200) += gpio-mpc5200.o
obj-$(CONFIG_GPIO_MPC8XXX) += gpio-mpc8xxx.o
+obj-$(CONFIG_GPIO_MSIC) += gpio-msic.o
obj-$(CONFIG_GPIO_MSM_V1) += gpio-msm-v1.o
obj-$(CONFIG_GPIO_MSM_V2) += gpio-msm-v2.o
obj-$(CONFIG_GPIO_MXC) += gpio-mxc.o
diff --git a/drivers/gpio/gpio-msic.c b/drivers/gpio/gpio-msic.c
new file mode 100644
index 0000000..71a838f
--- /dev/null
+++ b/drivers/gpio/gpio-msic.c
@@ -0,0 +1,339 @@
+/*
+ * Intel Medfield MSIC GPIO driver>
+ * Copyright (c) 2011, Intel Corporation.
+ *
+ * Author: Mathias Nyman <mathias.nyman@linux.intel.com>
+ * Based on intel_pmic_gpio.c
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/intel_msic.h>
+
+/* the offset for the mapping of global gpio pin to irq */
+#define MSIC_GPIO_IRQ_OFFSET 0x100
+
+#define MSIC_GPIO_DIR_IN 0
+#define MSIC_GPIO_DIR_OUT BIT(5)
+#define MSIC_GPIO_TRIG_FALL BIT(1)
+#define MSIC_GPIO_TRIG_RISE BIT(2)
+
+/* masks for msic gpio output GPIOxxxxCTLO registers */
+#define MSIC_GPIO_DIR_MASK BIT(5)
+#define MSIC_GPIO_DRV_MASK BIT(4)
+#define MSIC_GPIO_REN_MASK BIT(3)
+#define MSIC_GPIO_RVAL_MASK (BIT(2) | BIT(1))
+#define MSIC_GPIO_DOUT_MASK BIT(0)
+
+/* masks for msic gpio input GPIOxxxxCTLI registers */
+#define MSIC_GPIO_GLBYP_MASK BIT(5)
+#define MSIC_GPIO_DBNC_MASK (BIT(4) | BIT(3))
+#define MSIC_GPIO_INTCNT_MASK (BIT(2) | BIT(1))
+#define MSIC_GPIO_DIN_MASK BIT(0)
+
+#define MSIC_NUM_GPIO 24
+
+struct msic_gpio {
+ struct platform_device *pdev;
+ struct mutex buslock;
+ struct gpio_chip chip;
+ int irq;
+ unsigned irq_base;
+ unsigned long trig_change_mask;
+ unsigned trig_type;
+};
+
+/*
+ * MSIC has 24 gpios, 16 low voltage (1.2-1.8v) and 8 high voltage (3v).
+ * Both the high and low voltage gpios are divided in two banks.
+ * GPIOs are numbered with GPIO0LV0 as gpio_base in the following order:
+ * GPIO0LV0..GPIO0LV7: low voltage, bank 0, gpio_base
+ * GPIO1LV0..GPIO1LV7: low voltage, bank 1, gpio_base + 8
+ * GPIO0HV0..GPIO0HV3: high voltage, bank 0, gpio_base + 16
+ * GPIO1HV0..GPIO1HV3: high voltage, bank 1, gpio_base + 20
+ */
+
+static int msic_gpio_to_ireg(unsigned offset)
+{
+ if (offset >= MSIC_NUM_GPIO)
+ return -EINVAL;
+
+ if (offset < 8)
+ return INTEL_MSIC_GPIO0LV0CTLI - offset;
+ if (offset < 16)
+ return INTEL_MSIC_GPIO1LV0CTLI - offset + 8;
+ if (offset < 20)
+ return INTEL_MSIC_GPIO0HV0CTLI - offset + 16;
+
+ return INTEL_MSIC_GPIO1HV0CTLI - offset + 20;
+}
+
+static int msic_gpio_to_oreg(unsigned offset)
+{
+ if (offset >= MSIC_NUM_GPIO)
+ return -EINVAL;
+
+ if (offset < 8)
+ return INTEL_MSIC_GPIO0LV0CTLO - offset;
+ if (offset < 16)
+ return INTEL_MSIC_GPIO1LV0CTLO - offset + 8;
+ if (offset < 20)
+ return INTEL_MSIC_GPIO0HV0CTLO - offset + 16;
+
+ return INTEL_MSIC_GPIO1HV0CTLO + offset + 20;
+}
+
+static int msic_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+ int reg;
+
+ reg = msic_gpio_to_oreg(offset);
+ if (reg < 0)
+ return reg;
+
+ return intel_msic_reg_update(reg, MSIC_GPIO_DIR_IN, MSIC_GPIO_DIR_MASK);
+}
+
+static int msic_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ int reg;
+ unsigned mask;
+
+ value = (!!value) | MSIC_GPIO_DIR_OUT;
+ mask = MSIC_GPIO_DIR_MASK | MSIC_GPIO_DOUT_MASK;
+
+ reg = msic_gpio_to_oreg(offset);
+ if (reg < 0)
+ return reg;
+
+ return intel_msic_reg_update(reg, value, mask);
+}
+
+static int msic_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ u8 r;
+ int ret;
+ int reg;
+
+ reg = msic_gpio_to_ireg(offset);
+ if (reg < 0)
+ return reg;
+
+ ret = intel_msic_reg_read(reg, &r);
+ if (ret < 0)
+ return ret;
+
+ return r & MSIC_GPIO_DIN_MASK;
+}
+
+static void msic_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ int reg;
+
+ reg = msic_gpio_to_oreg(offset);
+ if (reg < 0)
+ return;
+
+ intel_msic_reg_update(reg, !!value , MSIC_GPIO_DOUT_MASK);
+}
+
+/*
+ * This is called from genirq with mg->buslock locked and
+ * irq_desc->lock held. We can not access the scu bus here, so we
+ * store the change and update in the bus_sync_unlock() function below
+ */
+static int msic_irq_type(struct irq_data *data, unsigned type)
+{
+ struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
+ u32 gpio = data->irq - mg->irq_base;
+
+ if (gpio >= mg->chip.ngpio)
+ return -EINVAL;
+
+ /* mark for which gpio the trigger changed, protected by buslock */
+ mg->trig_change_mask |= (1 << gpio);
+ mg->trig_type = type;
+
+ return 0;
+}
+
+static int msic_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+ struct msic_gpio *mg = container_of(chip, struct msic_gpio, chip);
+ return mg->irq_base + offset;
+}
+
+static void msic_bus_lock(struct irq_data *data)
+{
+ struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
+ mutex_lock(&mg->buslock);
+}
+
+static void msic_bus_sync_unlock(struct irq_data *data)
+{
+ struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
+ int offset;
+ int reg;
+ u8 trig = 0;
+
+ /* We can only get one change at a time as the buslock covers the
+ entire transaction. The irq_desc->lock is dropped before we are
+ called but that is fine */
+ if (mg->trig_change_mask) {
+ offset = __ffs(mg->trig_change_mask);
+
+ reg = msic_gpio_to_ireg(offset);
+ if (reg < 0)
+ goto out;
+
+ if (mg->trig_type & IRQ_TYPE_EDGE_RISING)
+ trig |= MSIC_GPIO_TRIG_RISE;
+ if (mg->trig_type & IRQ_TYPE_EDGE_FALLING)
+ trig |= MSIC_GPIO_TRIG_FALL;
+
+ intel_msic_reg_update(reg, trig, MSIC_GPIO_INTCNT_MASK);
+ mg->trig_change_mask = 0;
+ }
+out:
+ mutex_unlock(&mg->buslock);
+}
+
+/* Firmware does all the masking and unmasking for us, no masking here. */
+static void msic_irq_unmask(struct irq_data *data) { }
+
+static void msic_irq_mask(struct irq_data *data) { }
+
+static struct irq_chip msic_irqchip = {
+ .name = "MSIC-GPIO",
+ .irq_mask = msic_irq_mask,
+ .irq_unmask = msic_irq_unmask,
+ .irq_set_type = msic_irq_type,
+ .irq_bus_lock = msic_bus_lock,
+ .irq_bus_sync_unlock = msic_bus_sync_unlock,
+};
+
+static void msic_gpio_irq_handler(unsigned irq, struct irq_desc *desc)
+{
+ struct irq_data *data = irq_desc_get_irq_data(desc);
+ struct msic_gpio *mg = irq_data_get_irq_handler_data(data);
+ struct irq_chip *chip = irq_data_get_irq_chip(data);
+ struct intel_msic *msic = pdev_to_intel_msic(mg->pdev);
+ int i;
+ int bitnr;
+ u8 pin;
+ unsigned long pending = 0;
+
+ for (i = 0; i < (mg->chip.ngpio / BITS_PER_BYTE); i++) {
+ intel_msic_irq_read(msic, INTEL_MSIC_GPIO0LVIRQ + i, &pin);
+ pending = pin;
+
+ if (pending) {
+ for_each_set_bit(bitnr, &pending, BITS_PER_BYTE)
+ generic_handle_irq(mg->irq_base +
+ (i * BITS_PER_BYTE) + bitnr);
+ }
+ }
+ chip->irq_eoi(data);
+}
+
+static int __devinit platform_msic_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct intel_msic_gpio_pdata *pdata = dev->platform_data;
+ struct msic_gpio *mg;
+ int irq = platform_get_irq(pdev, 0);
+ int retval;
+ int i;
+
+ if (irq < 0) {
+ dev_err(dev, "no IRQ line\n");
+ return -EINVAL;
+ }
+
+ if (!pdata || !pdata->gpio_base) {
+ dev_err(dev, "incorrect or missing platform data\n");
+ return -EINVAL;
+ }
+
+ mg = kzalloc(sizeof(*mg), GFP_KERNEL);
+ if (!mg)
+ return -ENOMEM;
+
+ dev_set_drvdata(dev, mg);
+
+ mg->pdev = pdev;
+ mg->irq = irq;
+ mg->irq_base = pdata->gpio_base + MSIC_GPIO_IRQ_OFFSET;
+ mg->chip.label = "msic_gpio";
+ mg->chip.direction_input = msic_gpio_direction_input;
+ mg->chip.direction_output = msic_gpio_direction_output;
+ mg->chip.get = msic_gpio_get;
+ mg->chip.set = msic_gpio_set;
+ mg->chip.to_irq = msic_gpio_to_irq;
+ mg->chip.base = pdata->gpio_base;
+ mg->chip.ngpio = MSIC_NUM_GPIO;
+ mg->chip.can_sleep = 1;
+ mg->chip.dev = dev;
+
+ mutex_init(&mg->buslock);
+
+ retval = gpiochip_add(&mg->chip);
+ if (retval) {
+ dev_err(dev, "Adding MSIC gpio chip failed\n");
+ goto err;
+ }
+
+ for (i = 0; i < mg->chip.ngpio; i++) {
+ irq_set_chip_data(i + mg->irq_base, mg);
+ irq_set_chip_and_handler_name(i + mg->irq_base,
+ &msic_irqchip,
+ handle_simple_irq,
+ "demux");
+ }
+ irq_set_chained_handler(mg->irq, msic_gpio_irq_handler);
+ irq_set_handler_data(mg->irq, mg);
+
+ return 0;
+err:
+ kfree(mg);
+ return retval;
+}
+
+static struct platform_driver platform_msic_gpio_driver = {
+ .driver = {
+ .name = "msic_gpio",
+ .owner = THIS_MODULE,
+ },
+ .probe = platform_msic_gpio_probe,
+};
+
+static int __init platform_msic_gpio_init(void)
+{
+ return platform_driver_register(&platform_msic_gpio_driver);
+}
+
+subsys_initcall(platform_msic_gpio_init);
+
+MODULE_AUTHOR("Mathias Nyman <mathias.nyman@linux.intel.com>");
+MODULE_DESCRIPTION("Intel Medfield MSIC GPIO driver");
+MODULE_LICENSE("GPL v2");