lkml.org 
[lkml]   [2010]   [Jun]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/3 V3] gpio: add STMPE811 gpio controller support
Date
This one adds a driver for STMPE811 GPIO controller. STMPE811 is a
multifunction device. Hence this driver depends on stmpe811_core
driver for core functionalities. The gpio chip is registered to
gpiolib. Interrupts are currently not supported.

Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
---
V2 changes:
* include subsystem headers since they are now removed from the mfd
core header file
V3 Changes:
* reformated platform data comments to kernel-doc style
* move platform data stuff from core patch to herein.

drivers/gpio/Kconfig | 10 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/stmpe811_gpio.c | 238 ++++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/stmpe811.h | 16 +++
4 files changed, 265 insertions(+), 0 deletions(-)
create mode 100644 drivers/gpio/stmpe811_gpio.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 724038d..38307e5 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -249,6 +249,16 @@ config GPIO_ADP5588
To compile this driver as a module, choose M here: the module will be
called adp5588-gpio.

+config GPIO_STMPE811
+ tristate "STMPE811 I2C MFD GPIO expander"
+ depends on I2C
+ depends on MFD_STMPE811
+ help
+ This option enables support for 8 GPIOs found
+ on STMicroelectronics STMPE811 multifunction devices.
+ To compile this driver as a module, choose M here: the module will be
+ called stmpe811_gpio.
+
comment "PCI GPIO expanders:"

config GPIO_CS5535
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 51c3cdd..7b184aa 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -31,3 +31,4 @@ obj-$(CONFIG_GPIO_WM8994) += wm8994-gpio.o
obj-$(CONFIG_GPIO_SCH) += sch_gpio.o
obj-$(CONFIG_GPIO_RDC321X) += rdc321x-gpio.o
obj-$(CONFIG_GPIO_JANZ_TTL) += janz-ttl.o
+obj-$(CONFIG_GPIO_STMPE811) += stmpe811_gpio.o
diff --git a/drivers/gpio/stmpe811_gpio.c b/drivers/gpio/stmpe811_gpio.c
new file mode 100644
index 0000000..507fb5b
--- /dev/null
+++ b/drivers/gpio/stmpe811_gpio.c
@@ -0,0 +1,238 @@
+/*
+ * stmpe811_gpio.c -- gpiolib support for STMicroelectronics STMPE811 chip.
+ *
+ * (c)2010 Luotao Fu <l.fu@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/workqueue.h>
+
+#include <linux/mfd/stmpe811.h>
+
+#define STMPE811_GPIO_NAME "stmpe811-gpio"
+
+struct stmpe811_gpio {
+ struct stmpe811 *stm;
+ struct gpio_chip gpio;
+};
+
+static inline struct stmpe811_gpio *to_stmpe811_gpio(struct gpio_chip *chip)
+{
+ return container_of(chip, struct stmpe811_gpio, gpio);
+}
+
+static int stmpe811_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+ struct stmpe811_gpio *stm_gpio = to_stmpe811_gpio(chip);
+
+ return stmpe811_reg_clear_bits(stm_gpio->stm,
+ STMPE811_REG_GPIO_DIR, BIT(offset));
+}
+
+static int stmpe811_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct stmpe811_gpio *stm_gpio = to_stmpe811_gpio(chip);
+ uint8_t gpio_sta;
+ int ret;
+
+ ret = stmpe811_reg_read(stm_gpio->stm,
+ STMPE811_REG_GPIO_MP_STA, &gpio_sta);
+ if (ret)
+ return ret;
+
+ if (gpio_sta & BIT(offset))
+ return 1;
+ else
+ return 0;
+}
+
+static inline int __stmpe811_gpio_set(struct stmpe811 *stm,
+ unsigned offset, int value)
+{
+ int ret;
+
+ if (value)
+ ret = stmpe811_reg_write(stm, STMPE811_REG_GPIO_SET_PIN,
+ BIT(offset));
+ else
+ ret = stmpe811_reg_write(stm, STMPE811_REG_GPIO_CLR_PIN,
+ BIT(offset));
+
+ return ret;
+}
+
+static int stmpe811_gpio_direction_out(struct gpio_chip *chip, unsigned offset,
+ int value)
+{
+ struct stmpe811_gpio *stm_gpio = to_stmpe811_gpio(chip);
+ struct stmpe811 *stm = stm_gpio->stm;
+ int ret;
+
+ ret = stmpe811_reg_set_bits(stm, STMPE811_REG_GPIO_DIR, BIT(offset));
+ if (ret)
+ goto out;
+
+ ret = __stmpe811_gpio_set(stm, offset, value);
+out:
+ return ret;
+}
+
+static void stmpe811_gpio_set(struct gpio_chip *chip, unsigned offset,
+ int value)
+{
+ struct stmpe811_gpio *stm_gpio = to_stmpe811_gpio(chip);
+
+ __stmpe811_gpio_set(stm_gpio->stm, offset, value);
+}
+
+static int stmpe811_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+ struct stmpe811_gpio *stm_gpio = to_stmpe811_gpio(chip);
+ struct stmpe811 *stm = stm_gpio->stm;
+
+ if (offset > 3 && (stm->active_flag & STMPE811_USE_TS))
+ return 1;
+ else
+ return stmpe811_reg_set_bits(stm, STMPE811_REG_GPIO_AF,
+ BIT(offset));
+}
+
+static struct gpio_chip gpio_chip = {
+ .label = STMPE811_GPIO_NAME,
+ .owner = THIS_MODULE,
+ .direction_input = stmpe811_gpio_direction_in,
+ .get = stmpe811_gpio_get,
+ .direction_output = stmpe811_gpio_direction_out,
+ .set = stmpe811_gpio_set,
+ .request = stmpe811_gpio_request,
+ .can_sleep = 1,
+};
+
+static int __devinit stmpe811_gpio_probe(struct platform_device *pdev)
+{
+ struct stmpe811 *stm = dev_get_drvdata(pdev->dev.parent);
+ struct stmpe811_platform_data *pdata = stm->pdata;
+ struct stmpe811_gpio_platform_data *gpio_pdata = NULL;
+ struct stmpe811_gpio *stm_gpio;
+
+ int ret, tmp;
+
+ stm_gpio = kzalloc(sizeof(*stm_gpio), GFP_KERNEL);
+ if (!stm_gpio)
+ return -ENOMEM;
+
+ stm_gpio->stm = stm;
+ stm_gpio->gpio = gpio_chip;
+ stm_gpio->gpio.ngpio = 8;
+ stm_gpio->gpio.dev = &pdev->dev;
+
+ if (pdata)
+ gpio_pdata = pdata->gpio_pdata;
+
+ if (gpio_pdata && gpio_pdata->gpio_base)
+ stm_gpio->gpio.base = gpio_pdata->gpio_base;
+ else
+ stm_gpio->gpio.base = -1;
+
+ ret = gpiochip_add(&stm_gpio->gpio);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
+ goto err_free_stmgpio;
+ }
+ /* enable clock supply */
+ ret = stmpe811_reg_clear_bits(stm, STMPE811_REG_SYS_CTRL2,
+ STMPE811_SYS_CTRL2_GPIO_OFF);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not enable clock for gpio\n");
+ goto err_free_gpiochip;
+ }
+
+ if (gpio_pdata && gpio_pdata->setup) {
+ ret = gpio_pdata->setup(stm);
+
+ if (ret != 0) {
+ dev_err(&pdev->dev, "setup hook failed, %d\n",
+ ret);
+ goto err_free_gpiochip;
+ }
+ }
+
+ dev_info(&pdev->dev, "registerd gpios %d..%d on a stmpe811\n",
+ stm_gpio->gpio.base,
+ stm_gpio->gpio.base + stm_gpio->gpio.ngpio - 1);
+ platform_set_drvdata(pdev, stm_gpio);
+
+ return ret;
+
+err_free_gpiochip:
+ tmp = gpiochip_remove(&stm_gpio->gpio);
+ if (tmp) {
+ dev_err(&pdev->dev, "Could net remove gpio chip\n");
+ return ret;
+ }
+err_free_stmgpio:
+ kfree(stm_gpio);
+ return ret;
+}
+
+static int __devexit stmpe811_gpio_remove(struct platform_device *pdev)
+{
+ struct stmpe811_gpio *stm_gpio = platform_get_drvdata(pdev);
+ struct stmpe811_platform_data *pdata = stm_gpio->stm->pdata;
+ struct stmpe811_gpio_platform_data *gpio_pdata = NULL;
+ int ret;
+
+ if (pdata)
+ gpio_pdata = pdata->gpio_pdata;
+
+ if (gpio_pdata && gpio_pdata->remove)
+ gpio_pdata->remove(stm_gpio->stm);
+
+ /* disable clock supply */
+ stmpe811_reg_set_bits(stm_gpio->stm, STMPE811_REG_SYS_CTRL2,
+ STMPE811_SYS_CTRL2_GPIO_OFF);
+
+ ret = gpiochip_remove(&stm_gpio->gpio);
+ if (ret == 0)
+ kfree(stm_gpio);
+
+ return ret;
+}
+
+static struct platform_driver stmpe811_gpio_driver = {
+ .driver.name = STMPE811_GPIO_NAME,
+ .driver.owner = THIS_MODULE,
+ .probe = stmpe811_gpio_probe,
+ .remove = __devexit_p(stmpe811_gpio_remove),
+};
+
+static int __init stmpe811_gpio_init(void)
+{
+ return platform_driver_register(&stmpe811_gpio_driver);
+}
+
+subsys_initcall(stmpe811_gpio_init);
+
+static void __exit stmpe811_gpio_exit(void)
+{
+ platform_driver_unregister(&stmpe811_gpio_driver);
+}
+
+module_exit(stmpe811_gpio_exit);
+
+MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
+MODULE_DESCRIPTION("GPIO interface for STMicroelectronics STMPE811");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" STMPE811_GPIO_NAME);
diff --git a/include/linux/mfd/stmpe811.h b/include/linux/mfd/stmpe811.h
index 8e2b55e..736b4eb 100644
--- a/include/linux/mfd/stmpe811.h
+++ b/include/linux/mfd/stmpe811.h
@@ -94,12 +94,27 @@ struct stmpe811 {
};

/**
+ * struct stmpe811_gpio_platform_data - stmpe811 gpio controller platform data
+ *
+ * @gpio_base: number of the chip's first GPIO
+ * @setup: optional callback issued once the GPIOs are valid
+ * @remove: optional callback issued before the GPIOs are invalidated
+ *
+ * */
+struct stmpe811_gpio_platform_data {
+ unsigned int gpio_base;
+ int (*setup) (struct stmpe811 *stm);
+ void (*remove) (struct stmpe811 *stm);
+};
+
+/**
* struct stmpe811_platform_data - stmpe811 core platform data
*
* @flags: define which subdevices should be supported
* @irq_high: IRQ is active high.
* @irq_rev_pol: IRQ line is connected with reversed polarity
* @irq_base: board dependt irq number of the first irq for the irq chip
+ * @gpio_pdata: pointer to gpio controller platform data
* registered by the core.
*
* */
@@ -110,6 +125,7 @@ struct stmpe811_platform_data {
unsigned int irq_high;
unsigned int irq_rev_pol;
int irq_base;
+ struct stmpe811_gpio_platform_data *gpio_pdata;
};

int stmpe811_block_read(struct stmpe811 *stm, u8 reg, uint len, u8 *val);
--
1.7.1


\
 
 \ /
  Last update: 2010-06-15 11:05    [from the cache]
©2003-2011 Jasper Spaans