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Input: ad7879 - support auxiliary GPIOs via gpiolib
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Drop the simple fancy sysfs hooks for the aux GPIOs and expose these via
the gpiolib interface so that other drivers can use them.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
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Michael Hennerich authored and Dmitry Torokhov committed Jan 19, 2010
1 parent c332e9f commit ec51b7f
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Showing 2 changed files with 149 additions and 60 deletions.
197 changes: 141 additions & 56 deletions drivers/input/touchscreen/ad7879.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -47,6 +47,7 @@
#include <linux/workqueue.h>
#include <linux/spi/spi.h>
#include <linux/i2c.h>
#include <linux/gpio.h>

#include <linux/spi/ad7879.h>

Expand Down Expand Up @@ -132,7 +133,9 @@ struct ad7879 {
struct input_dev *input;
struct work_struct work;
struct timer_list timer;

#ifdef CONFIG_GPIOLIB
struct gpio_chip gc;
#endif
struct mutex mutex;
unsigned disabled:1; /* P: mutex */

Expand All @@ -150,11 +153,9 @@ struct ad7879 {
u8 median;
u16 x_plate_ohms;
u16 pressure_max;
u16 gpio_init;
u16 cmd_crtl1;
u16 cmd_crtl2;
u16 cmd_crtl3;
unsigned gpio:1;
};

static int ad7879_read(bus_device *, u8);
Expand Down Expand Up @@ -237,24 +238,6 @@ static irqreturn_t ad7879_irq(int irq, void *handle)

static void ad7879_setup(struct ad7879 *ts)
{
ts->cmd_crtl3 = AD7879_YPLUS_BIT |
AD7879_XPLUS_BIT |
AD7879_Z2_BIT |
AD7879_Z1_BIT |
AD7879_TEMPMASK_BIT |
AD7879_AUXVBATMASK_BIT |
AD7879_GPIOALERTMASK_BIT;

ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
AD7879_AVG(ts->averaging) |
AD7879_MFS(ts->median) |
AD7879_FCD(ts->first_conversion_delay) |
ts->gpio_init;

ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
AD7879_ACQ(ts->acquisition_time) |
AD7879_TMR(ts->pen_down_acc_interval);

ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
ad7879_write(ts->bus, AD7879_REG_CTRL3, ts->cmd_crtl3);
ad7879_write(ts->bus, AD7879_REG_CTRL1, ts->cmd_crtl1);
Expand Down Expand Up @@ -324,48 +307,132 @@ static ssize_t ad7879_disable_store(struct device *dev,

static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);

static ssize_t ad7879_gpio_show(struct device *dev,
struct device_attribute *attr, char *buf)
static struct attribute *ad7879_attributes[] = {
&dev_attr_disable.attr,
NULL
};

static const struct attribute_group ad7879_attr_group = {
.attrs = ad7879_attributes,
};

#ifdef CONFIG_GPIOLIB
static int ad7879_gpio_direction_input(struct gpio_chip *chip,
unsigned gpio)
{
struct ad7879 *ts = dev_get_drvdata(dev);
struct ad7879 *ts = container_of(chip, struct ad7879, gc);
int err;

return sprintf(buf, "%u\n", ts->gpio);
mutex_lock(&ts->mutex);
ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
err = ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
mutex_unlock(&ts->mutex);

return err;
}

static ssize_t ad7879_gpio_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
static int ad7879_gpio_direction_output(struct gpio_chip *chip,
unsigned gpio, int level)
{
struct ad7879 *ts = dev_get_drvdata(dev);
unsigned long val;
int error;
struct ad7879 *ts = container_of(chip, struct ad7879, gc);
int err;

error = strict_strtoul(buf, 10, &val);
if (error)
return error;
mutex_lock(&ts->mutex);
ts->cmd_crtl2 &= ~AD7879_GPIODIR;
ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
if (level)
ts->cmd_crtl2 |= AD7879_GPIO_DATA;
else
ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;

err = ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
mutex_unlock(&ts->mutex);

return err;
}

static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
struct ad7879 *ts = container_of(chip, struct ad7879, gc);
u16 val;

mutex_lock(&ts->mutex);
ts->gpio = !!val;
error = ad7879_write(ts->bus, AD7879_REG_CTRL2,
ts->gpio ?
ts->cmd_crtl2 & ~AD7879_GPIO_DATA :
ts->cmd_crtl2 | AD7879_GPIO_DATA);
val = ad7879_read(ts->bus, AD7879_REG_CTRL2);
mutex_unlock(&ts->mutex);

return error ? : count;
return !!(val & AD7879_GPIO_DATA);
}

static DEVICE_ATTR(gpio, 0664, ad7879_gpio_show, ad7879_gpio_store);
static void ad7879_gpio_set_value(struct gpio_chip *chip,
unsigned gpio, int value)
{
struct ad7879 *ts = container_of(chip, struct ad7879, gc);

static struct attribute *ad7879_attributes[] = {
&dev_attr_disable.attr,
&dev_attr_gpio.attr,
NULL
};
mutex_lock(&ts->mutex);
if (value)
ts->cmd_crtl2 |= AD7879_GPIO_DATA;
else
ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;

static const struct attribute_group ad7879_attr_group = {
.attrs = ad7879_attributes,
};
ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
mutex_unlock(&ts->mutex);
}

static int __devinit ad7879_gpio_add(struct device *dev)
{
struct ad7879 *ts = dev_get_drvdata(dev);
struct ad7879_platform_data *pdata = dev->platform_data;
int ret = 0;

if (pdata->gpio_export) {
ts->gc.direction_input = ad7879_gpio_direction_input;
ts->gc.direction_output = ad7879_gpio_direction_output;
ts->gc.get = ad7879_gpio_get_value;
ts->gc.set = ad7879_gpio_set_value;
ts->gc.can_sleep = 1;
ts->gc.base = pdata->gpio_base;
ts->gc.ngpio = 1;
ts->gc.label = "AD7879-GPIO";
ts->gc.owner = THIS_MODULE;
ts->gc.dev = dev;

ret = gpiochip_add(&ts->gc);
if (ret)
dev_err(dev, "failed to register gpio %d\n",
ts->gc.base);
}

return ret;
}

/*
* We mark ad7879_gpio_remove inline so there is a chance the code
* gets discarded when not needed. We can't do __devinit/__devexit
* markup since it is used in both probe and remove methods.
*/
static inline void ad7879_gpio_remove(struct device *dev)
{
struct ad7879 *ts = dev_get_drvdata(dev);
struct ad7879_platform_data *pdata = dev->platform_data;
int ret;

if (pdata->gpio_export) {
ret = gpiochip_remove(&ts->gc);
if (ret)
dev_err(dev, "failed to remove gpio %d\n",
ts->gc.base);
}
}
#else
static inline int ad7879_gpio_add(struct device *dev)
{
return 0;
}

static inline void ad7879_gpio_remove(struct device *dev)
{
}
#endif

static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
{
Expand Down Expand Up @@ -403,12 +470,6 @@ static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
ts->median = pdata->median;

if (pdata->gpio_output)
ts->gpio_init = AD7879_GPIO_EN |
(pdata->gpio_default ? 0 : AD7879_GPIO_DATA);
else
ts->gpio_init = AD7879_GPIO_EN | AD7879_GPIODIR;

snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&bus->dev));

input_dev->name = "AD7879 Touchscreen";
Expand Down Expand Up @@ -446,6 +507,23 @@ static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
goto err_free_mem;
}

ts->cmd_crtl3 = AD7879_YPLUS_BIT |
AD7879_XPLUS_BIT |
AD7879_Z2_BIT |
AD7879_Z1_BIT |
AD7879_TEMPMASK_BIT |
AD7879_AUXVBATMASK_BIT |
AD7879_GPIOALERTMASK_BIT;

ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
AD7879_AVG(ts->averaging) |
AD7879_MFS(ts->median) |
AD7879_FCD(ts->first_conversion_delay);

ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
AD7879_ACQ(ts->acquisition_time) |
AD7879_TMR(ts->pen_down_acc_interval);

ad7879_setup(ts);

err = request_irq(bus->irq, ad7879_irq,
Expand All @@ -460,15 +538,21 @@ static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
if (err)
goto err_free_irq;

err = input_register_device(input_dev);
err = ad7879_gpio_add(&bus->dev);
if (err)
goto err_remove_attr;

err = input_register_device(input_dev);
if (err)
goto err_remove_gpio;

dev_info(&bus->dev, "Rev.%d touchscreen, irq %d\n",
revid >> 8, bus->irq);

return 0;

err_remove_gpio:
ad7879_gpio_remove(&bus->dev);
err_remove_attr:
sysfs_remove_group(&bus->dev.kobj, &ad7879_attr_group);
err_free_irq:
Expand All @@ -481,6 +565,7 @@ static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)

static int __devexit ad7879_destroy(bus_device *bus, struct ad7879 *ts)
{
ad7879_gpio_remove(&bus->dev);
ad7879_disable(ts);
sysfs_remove_group(&ts->bus->dev.kobj, &ad7879_attr_group);
free_irq(ts->bus->irq, ts);
Expand Down
12 changes: 8 additions & 4 deletions include/linux/spi/ad7879.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,8 +28,12 @@ struct ad7879_platform_data {
* 1 = 4, 2 = 8, 3 = 16 (median > averaging)
*/
u8 median;
/* 1 = AUX/VBAT/GPIO set to GPIO Output */
u8 gpio_output;
/* Initial GPIO pin state (valid if gpio_output = 1) */
u8 gpio_default;
/* 1 = AUX/VBAT/GPIO export GPIO to gpiolib
* requires CONFIG_GPIOLIB
*/
bool gpio_export;
/* identifies the first GPIO number handled by this chip;
* or, if negative, requests dynamic ID allocation.
*/
s32 gpio_base;
};

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