// SPDX-License-Identifier: GPL-2.0
/*
* GPIO driver for TI TPS65219 PMICs
*
* Copyright (C) 2022 Texas Instruments Incorporated - http://www.ti.com/
*/
#include <linux/bits.h>
#include <linux/gpio/driver.h>
#include <linux/mfd/tps65219.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#define TPS65219_GPIO0_DIR_MASK BIT(3)
#define TPS65219_GPIO0_OFFSET 2
#define TPS65219_GPIO0_IDX 0
#define TPS65219_GPIO_DIR_IN 1
#define TPS65219_GPIO_DIR_OUT 0
struct tps65219_gpio {
struct gpio_chip gpio_chip;
struct tps65219 *tps;
};
static int tps65219_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
struct tps65219_gpio *gpio = gpiochip_get_data(gc);
int ret, val;
if (offset != TPS65219_GPIO0_IDX)
return GPIO_LINE_DIRECTION_OUT;
ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG, &val);
if (ret)
return ret;
return !!(val & TPS65219_GPIO0_DIR_MASK);
}
static int tps65219_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
struct tps65219_gpio *gpio = gpiochip_get_data(gc);
struct device *dev = gpio->tps->dev;
int ret, val;
if (offset != TPS65219_GPIO0_IDX) {
dev_err(dev, "GPIO%d is output only, cannot get\n", offset);
return -ENOTSUPP;
}
ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_CTRL, &val);
if (ret)
return ret;
ret = !!(val & BIT(TPS65219_MFP_GPIO_STATUS_MASK));
dev_warn(dev, "GPIO%d = %d, MULTI_DEVICE_ENABLE, not a standard GPIO\n", offset, ret);
/*
* Depending on NVM config, return an error if direction is output, otherwise the GPIO0
* status bit.
*/
if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_OUT)
return -ENOTSUPP;
return ret;
}
static void tps65219_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
{
struct tps65219_gpio *gpio = gpiochip_get_data(gc);
struct device *dev = gpio->tps->dev;
int v, mask, bit;
bit = (offset == TPS65219_GPIO0_IDX) ? TPS65219_GPIO0_OFFSET : offset - 1;
mask = BIT(bit);
v = value ? mask : 0;
if (regmap_update_bits(gpio->tps->regmap, TPS65219_REG_GENERAL_CONFIG, mask, v))
dev_err(dev, "GPIO%d, set to value %d failed.\n", offset, value);
}
static int tps65219_gpio_change_direction(struct gpio_chip *gc, unsigned int offset,
unsigned int direction)
{
struct tps65219_gpio *gpio = gpiochip_get_data(gc);
struct device *dev = gpio->tps->dev;
/*
* Documentation is stating that GPIO0 direction must not be changed in Linux:
* Table 8-34. MFP_1_CONFIG(3): MULTI_DEVICE_ENABLE, should only be changed in INITIALIZE
* state (prior to ON Request).
* Set statically by NVM, changing direction in application can cause a hang.
* Below can be used for test purpose only.
*/
if (IS_ENABLED(CONFIG_DEBUG_GPIO)) {
int ret = regmap_update_bits(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG,
TPS65219_GPIO0_DIR_MASK, direction);
if (ret) {
dev_err(dev,
"GPIO DEBUG enabled: Fail to change direction to %u for GPIO%d.\n",
direction, offset);
return ret;
}
}
dev_err(dev,
"GPIO%d direction set by NVM, change to %u failed, not allowed by specification\n",
offset, direction);
return -ENOTSUPP;
}
static int tps65219_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
{
struct tps65219_gpio *gpio = gpiochip_get_data(gc);
struct device *dev = gpio->tps->dev;
if (offset != TPS65219_GPIO0_IDX) {
dev_err(dev, "GPIO%d is output only, cannot change to input\n", offset);
return -ENOTSUPP;
}
if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_IN)
return 0;
return tps65219_gpio_change_direction(gc, offset, TPS65219_GPIO_DIR_IN);
}
static int tps65219_gpio_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
{
tps65219_gpio_set(gc, offset, value);
if (offset != TPS65219_GPIO0_IDX)
return 0;
if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_OUT)
return 0;
return tps65219_gpio_change_direction(gc, offset, TPS65219_GPIO_DIR_OUT);
}
static const struct gpio_chip tps65219_template_chip = {
.label = "tps65219-gpio",
.owner = THIS_MODULE,
.get_direction = tps65219_gpio_get_direction,
.direction_input = tps65219_gpio_direction_input,
.direction_output = tps65219_gpio_direction_output,
.get = tps65219_gpio_get,
.set = tps65219_gpio_set,
.base = -1,
.ngpio = 3,
.can_sleep = true,
};
static int tps65219_gpio_probe(struct platform_device *pdev)
{
struct tps65219 *tps = dev_get_drvdata(pdev->dev.parent);
struct tps65219_gpio *gpio;
gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return -ENOMEM;
gpio->tps = tps;
gpio->gpio_chip = tps65219_template_chip;
gpio->gpio_chip.parent = tps->dev;
return devm_gpiochip_add_data(&pdev->dev, &gpio->gpio_chip, gpio);
}
static struct platform_driver tps65219_gpio_driver = {
.driver = {
.name = "tps65219-gpio",
},
.probe = tps65219_gpio_probe,
};
module_platform_driver(tps65219_gpio_driver);
MODULE_ALIAS("platform:tps65219-gpio");
MODULE_AUTHOR("Jonathan Cormier <jcormier@criticallink.com>");
MODULE_DESCRIPTION("TPS65219 GPIO driver");
MODULE_LICENSE("GPL");
