linux-stable/drivers/gpio/gpio-lp873x.c
Mika Westerberg 2956b5d94a pinctrl / gpio: Introduce .set_config() callback for GPIO chips
Currently we already have two pin configuration related callbacks
available for GPIO chips .set_single_ended() and .set_debounce(). In
future we expect to have even more, which does not scale well if we need
to add yet another callback to the GPIO chip structure for each possible
configuration parameter.

Better solution is to reuse what we already have available in the
generic pinconf.

To support this, we introduce a new .set_config() callback for GPIO
chips. The callback takes a single packed pin configuration value as
parameter. This can then be extended easily beyond what is currently
supported by just adding new types to the generic pinconf enum.

If the GPIO driver is backed up by a pinctrl driver the GPIO driver can
just assign gpiochip_generic_config() (introduced in this patch) to
.set_config and that will take care configuration requests are directed
to the pinctrl driver.

We then convert the existing drivers over .set_config() and finally
remove the .set_single_ended() and .set_debounce() callbacks.

Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-26 15:27:37 +01:00

183 lines
4.5 KiB
C

/*
* Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
* Keerthy <j-keerthy@ti.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether expressed or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License version 2 for more details.
*
* Based on the TPS65218 driver
*/
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/lp873x.h>
#define BITS_PER_GPO 0x4
#define LP873X_GPO_CTRL_OD 0x2
struct lp873x_gpio {
struct gpio_chip chip;
struct lp873x *lp873;
};
static int lp873x_gpio_get_direction(struct gpio_chip *chip,
unsigned int offset)
{
/* This device is output only */
return 0;
}
static int lp873x_gpio_direction_input(struct gpio_chip *chip,
unsigned int offset)
{
/* This device is output only */
return -EINVAL;
}
static int lp873x_gpio_direction_output(struct gpio_chip *chip,
unsigned int offset, int value)
{
struct lp873x_gpio *gpio = gpiochip_get_data(chip);
/* Set the initial value */
return regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
BIT(offset * BITS_PER_GPO),
value ? BIT(offset * BITS_PER_GPO) : 0);
}
static int lp873x_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct lp873x_gpio *gpio = gpiochip_get_data(chip);
int ret, val;
ret = regmap_read(gpio->lp873->regmap, LP873X_REG_GPO_CTRL, &val);
if (ret < 0)
return ret;
return val & BIT(offset * BITS_PER_GPO);
}
static void lp873x_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
struct lp873x_gpio *gpio = gpiochip_get_data(chip);
regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
BIT(offset * BITS_PER_GPO),
value ? BIT(offset * BITS_PER_GPO) : 0);
}
static int lp873x_gpio_request(struct gpio_chip *gc, unsigned int offset)
{
struct lp873x_gpio *gpio = gpiochip_get_data(gc);
int ret;
switch (offset) {
case 0:
/* No MUX Set up Needed for GPO */
break;
case 1:
/* Setup the CLKIN_PIN_SEL MUX to GPO2 */
ret = regmap_update_bits(gpio->lp873->regmap, LP873X_REG_CONFIG,
LP873X_CONFIG_CLKIN_PIN_SEL, 0);
if (ret)
return ret;
break;
default:
return -EINVAL;
}
return 0;
}
static int lp873x_gpio_set_config(struct gpio_chip *gc, unsigned offset,
unsigned long config)
{
struct lp873x_gpio *gpio = gpiochip_get_data(gc);
switch (pinconf_to_config_param(config)) {
case PIN_CONFIG_DRIVE_OPEN_DRAIN:
return regmap_update_bits(gpio->lp873->regmap,
LP873X_REG_GPO_CTRL,
BIT(offset * BITS_PER_GPO +
LP873X_GPO_CTRL_OD),
BIT(offset * BITS_PER_GPO +
LP873X_GPO_CTRL_OD));
case PIN_CONFIG_DRIVE_PUSH_PULL:
return regmap_update_bits(gpio->lp873->regmap,
LP873X_REG_GPO_CTRL,
BIT(offset * BITS_PER_GPO +
LP873X_GPO_CTRL_OD), 0);
default:
return -ENOTSUPP;
}
}
static const struct gpio_chip template_chip = {
.label = "lp873x-gpio",
.owner = THIS_MODULE,
.request = lp873x_gpio_request,
.get_direction = lp873x_gpio_get_direction,
.direction_input = lp873x_gpio_direction_input,
.direction_output = lp873x_gpio_direction_output,
.get = lp873x_gpio_get,
.set = lp873x_gpio_set,
.set_config = lp873x_gpio_set_config,
.base = -1,
.ngpio = 2,
.can_sleep = true,
};
static int lp873x_gpio_probe(struct platform_device *pdev)
{
struct lp873x_gpio *gpio;
int ret;
gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return -ENOMEM;
platform_set_drvdata(pdev, gpio);
gpio->lp873 = dev_get_drvdata(pdev->dev.parent);
gpio->chip = template_chip;
gpio->chip.parent = gpio->lp873->dev;
ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
if (ret < 0) {
dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
return ret;
}
return 0;
}
static const struct platform_device_id lp873x_gpio_id_table[] = {
{ "lp873x-gpio", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, lp873x_gpio_id_table);
static struct platform_driver lp873x_gpio_driver = {
.driver = {
.name = "lp873x-gpio",
},
.probe = lp873x_gpio_probe,
.id_table = lp873x_gpio_id_table,
};
module_platform_driver(lp873x_gpio_driver);
MODULE_AUTHOR("Keerthy <j-keerthy@ti.com>");
MODULE_DESCRIPTION("LP873X GPIO driver");
MODULE_LICENSE("GPL v2");