gpio: Congatec Board Controller gpio driver

Add gpio support for the Congatec Board Controller.
This Board Controller has 14 GPIO pins.

The driver is probed by the Congatec Board Controller MFD driver.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20241001-congatec-board-controller-v3-2-39ceceed5c47@bootlin.com
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Thomas Richard 2024-10-01 13:53:28 +02:00 committed by Lee Jones
parent 6f1067cfbe
commit 4342bf63b6
3 changed files with 207 additions and 0 deletions

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@ -1287,6 +1287,16 @@ config GPIO_BD9571MWV
This driver can also be built as a module. If so, the module
will be called gpio-bd9571mwv.
config GPIO_CGBC
tristate "Congatec Board Controller GPIO support"
depends on MFD_CGBC
help
Select this option to enable GPIO support for the Congatec Board
Controller.
This driver can also be built as a module. If so, the module will be
called gpio-cgbc.
config GPIO_CROS_EC
tristate "ChromeOS EC GPIO support"
depends on CROS_EC

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@ -45,6 +45,7 @@ obj-$(CONFIG_GPIO_BD9571MWV) += gpio-bd9571mwv.o
obj-$(CONFIG_GPIO_BRCMSTB) += gpio-brcmstb.o
obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o
obj-$(CONFIG_GPIO_CADENCE) += gpio-cadence.o
obj-$(CONFIG_GPIO_CGBC) += gpio-cgbc.o
obj-$(CONFIG_GPIO_CLPS711X) += gpio-clps711x.o
obj-$(CONFIG_GPIO_SNPS_CREG) += gpio-creg-snps.o
obj-$(CONFIG_GPIO_CROS_EC) += gpio-cros-ec.o

196
drivers/gpio/gpio-cgbc.c Normal file
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@ -0,0 +1,196 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Congatec Board Controller GPIO driver
*
* Copyright (C) 2024 Bootlin
* Author: Thomas Richard <thomas.richard@bootlin.com>
*/
#include <linux/gpio/driver.h>
#include <linux/mfd/cgbc.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#define CGBC_GPIO_NGPIO 14
#define CGBC_GPIO_CMD_GET 0x64
#define CGBC_GPIO_CMD_SET 0x65
#define CGBC_GPIO_CMD_DIR_GET 0x66
#define CGBC_GPIO_CMD_DIR_SET 0x67
struct cgbc_gpio_data {
struct gpio_chip chip;
struct cgbc_device_data *cgbc;
struct mutex lock;
};
static int cgbc_gpio_cmd(struct cgbc_device_data *cgbc,
u8 cmd0, u8 cmd1, u8 cmd2, u8 *value)
{
u8 cmd[3] = {cmd0, cmd1, cmd2};
return cgbc_command(cgbc, cmd, sizeof(cmd), value, 1, NULL);
}
static int cgbc_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct cgbc_gpio_data *gpio = gpiochip_get_data(chip);
struct cgbc_device_data *cgbc = gpio->cgbc;
int ret;
u8 val;
scoped_guard(mutex, &gpio->lock)
ret = cgbc_gpio_cmd(cgbc, CGBC_GPIO_CMD_GET, (offset > 7) ? 1 : 0, 0, &val);
offset %= 8;
if (ret)
return ret;
else
return (int)(val & (u8)BIT(offset));
}
static void __cgbc_gpio_set(struct gpio_chip *chip,
unsigned int offset, int value)
{
struct cgbc_gpio_data *gpio = gpiochip_get_data(chip);
struct cgbc_device_data *cgbc = gpio->cgbc;
u8 val;
int ret;
ret = cgbc_gpio_cmd(cgbc, CGBC_GPIO_CMD_GET, (offset > 7) ? 1 : 0, 0, &val);
if (ret)
return;
if (value)
val |= BIT(offset % 8);
else
val &= ~(BIT(offset % 8));
cgbc_gpio_cmd(cgbc, CGBC_GPIO_CMD_SET, (offset > 7) ? 1 : 0, val, &val);
}
static void cgbc_gpio_set(struct gpio_chip *chip,
unsigned int offset, int value)
{
struct cgbc_gpio_data *gpio = gpiochip_get_data(chip);
scoped_guard(mutex, &gpio->lock)
__cgbc_gpio_set(chip, offset, value);
}
static int cgbc_gpio_direction_set(struct gpio_chip *chip,
unsigned int offset, int direction)
{
struct cgbc_gpio_data *gpio = gpiochip_get_data(chip);
struct cgbc_device_data *cgbc = gpio->cgbc;
int ret;
u8 val;
ret = cgbc_gpio_cmd(cgbc, CGBC_GPIO_CMD_DIR_GET, (offset > 7) ? 1 : 0, 0, &val);
if (ret)
goto end;
if (direction == GPIO_LINE_DIRECTION_IN)
val &= ~(BIT(offset % 8));
else
val |= BIT(offset % 8);
ret = cgbc_gpio_cmd(cgbc, CGBC_GPIO_CMD_DIR_SET, (offset > 7) ? 1 : 0, val, &val);
end:
return ret;
}
static int cgbc_gpio_direction_input(struct gpio_chip *chip,
unsigned int offset)
{
struct cgbc_gpio_data *gpio = gpiochip_get_data(chip);
guard(mutex)(&gpio->lock);
return cgbc_gpio_direction_set(chip, offset, GPIO_LINE_DIRECTION_IN);
}
static int cgbc_gpio_direction_output(struct gpio_chip *chip,
unsigned int offset, int value)
{
struct cgbc_gpio_data *gpio = gpiochip_get_data(chip);
guard(mutex)(&gpio->lock);
__cgbc_gpio_set(chip, offset, value);
return cgbc_gpio_direction_set(chip, offset, GPIO_LINE_DIRECTION_OUT);
}
static int cgbc_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
{
struct cgbc_gpio_data *gpio = gpiochip_get_data(chip);
struct cgbc_device_data *cgbc = gpio->cgbc;
int ret;
u8 val;
scoped_guard(mutex, &gpio->lock)
ret = cgbc_gpio_cmd(cgbc, CGBC_GPIO_CMD_DIR_GET, (offset > 7) ? 1 : 0, 0, &val);
if (ret)
return ret;
if (val & BIT(offset % 8))
return GPIO_LINE_DIRECTION_OUT;
else
return GPIO_LINE_DIRECTION_IN;
}
static int cgbc_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct cgbc_device_data *cgbc = dev_get_drvdata(dev->parent);
struct cgbc_gpio_data *gpio;
struct gpio_chip *chip;
int ret;
gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return -ENOMEM;
gpio->cgbc = cgbc;
platform_set_drvdata(pdev, gpio);
chip = &gpio->chip;
chip->label = dev_name(&pdev->dev);
chip->owner = THIS_MODULE;
chip->parent = dev;
chip->base = -1;
chip->direction_input = cgbc_gpio_direction_input;
chip->direction_output = cgbc_gpio_direction_output;
chip->get_direction = cgbc_gpio_get_direction;
chip->get = cgbc_gpio_get;
chip->set = cgbc_gpio_set;
chip->ngpio = CGBC_GPIO_NGPIO;
ret = devm_mutex_init(dev, &gpio->lock);
if (ret)
return ret;
ret = devm_gpiochip_add_data(dev, chip, gpio);
if (ret)
return dev_err_probe(dev, ret, "Could not register GPIO chip\n");
return 0;
}
static struct platform_driver cgbc_gpio_driver = {
.driver = {
.name = "cgbc-gpio",
},
.probe = cgbc_gpio_probe,
};
module_platform_driver(cgbc_gpio_driver);
MODULE_DESCRIPTION("Congatec Board Controller GPIO Driver");
MODULE_AUTHOR("Thomas Richard <thomas.richard@bootlin.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:cgbc-gpio");