diff options
Diffstat (limited to 'drivers/gpio/gpio-bd71828.c')
| -rw-r--r-- | drivers/gpio/gpio-bd71828.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-bd71828.c b/drivers/gpio/gpio-bd71828.c new file mode 100644 index 000000000..b2ccc320c --- /dev/null +++ b/drivers/gpio/gpio-bd71828.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (C) 2018 ROHM Semiconductors + +#include <linux/gpio/driver.h> +#include <linux/mfd/rohm-bd71828.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#define GPIO_OUT_REG(off) (BD71828_REG_GPIO_CTRL1 + (off)) +#define HALL_GPIO_OFFSET 3 + +struct bd71828_gpio { + struct regmap *regmap; + struct device *dev; + struct gpio_chip gpio; +}; + +static void bd71828_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + int ret; + struct bd71828_gpio *bdgpio = gpiochip_get_data(chip); + u8 val = (value) ? BD71828_GPIO_OUT_HI : BD71828_GPIO_OUT_LO; + + /* + * The HALL input pin can only be used as input. If this is the pin + * we are dealing with - then we are done + */ + if (offset == HALL_GPIO_OFFSET) + return; + + ret = regmap_update_bits(bdgpio->regmap, GPIO_OUT_REG(offset), + BD71828_GPIO_OUT_MASK, val); + if (ret) + dev_err(bdgpio->dev, "Could not set gpio to %d\n", value); +} + +static int bd71828_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + int ret; + unsigned int val; + struct bd71828_gpio *bdgpio = gpiochip_get_data(chip); + + if (offset == HALL_GPIO_OFFSET) + ret = regmap_read(bdgpio->regmap, BD71828_REG_IO_STAT, + &val); + else + ret = regmap_read(bdgpio->regmap, GPIO_OUT_REG(offset), + &val); + if (!ret) + ret = (val & BD71828_GPIO_OUT_MASK); + + return ret; +} + +static int bd71828_gpio_set_config(struct gpio_chip *chip, unsigned int offset, + unsigned long config) +{ + struct bd71828_gpio *bdgpio = gpiochip_get_data(chip); + + if (offset == HALL_GPIO_OFFSET) + return -ENOTSUPP; + + switch (pinconf_to_config_param(config)) { + case PIN_CONFIG_DRIVE_OPEN_DRAIN: + return regmap_update_bits(bdgpio->regmap, + GPIO_OUT_REG(offset), + BD71828_GPIO_DRIVE_MASK, + BD71828_GPIO_OPEN_DRAIN); + case PIN_CONFIG_DRIVE_PUSH_PULL: + return regmap_update_bits(bdgpio->regmap, + GPIO_OUT_REG(offset), + BD71828_GPIO_DRIVE_MASK, + BD71828_GPIO_PUSH_PULL); + default: + break; + } + return -ENOTSUPP; +} + +static int bd71828_get_direction(struct gpio_chip *chip, unsigned int offset) +{ + /* + * Pin usage is selected by OTP data. We can't read it runtime. Hence + * we trust that if the pin is not excluded by "gpio-reserved-ranges" + * the OTP configuration is set to OUT. (Other pins but HALL input pin + * on BD71828 can't really be used for general purpose input - input + * states are used for specific cases like regulator control or + * PMIC_ON_REQ. + */ + if (offset == HALL_GPIO_OFFSET) + return GPIO_LINE_DIRECTION_IN; + + return GPIO_LINE_DIRECTION_OUT; +} + +static int bd71828_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct bd71828_gpio *bdgpio; + + bdgpio = devm_kzalloc(dev, sizeof(*bdgpio), GFP_KERNEL); + if (!bdgpio) + return -ENOMEM; + + bdgpio->dev = dev; + bdgpio->gpio.parent = dev->parent; + bdgpio->gpio.label = "bd71828-gpio"; + bdgpio->gpio.owner = THIS_MODULE; + bdgpio->gpio.get_direction = bd71828_get_direction; + bdgpio->gpio.set_config = bd71828_gpio_set_config; + bdgpio->gpio.can_sleep = true; + bdgpio->gpio.get = bd71828_gpio_get; + bdgpio->gpio.set = bd71828_gpio_set; + bdgpio->gpio.base = -1; + + /* + * See if we need some implementation to mark some PINs as + * not controllable based on DT info or if core can handle + * "gpio-reserved-ranges" and exclude them from control + */ + bdgpio->gpio.ngpio = 4; + bdgpio->regmap = dev_get_regmap(dev->parent, NULL); + if (!bdgpio->regmap) + return -ENODEV; + + return devm_gpiochip_add_data(dev, &bdgpio->gpio, bdgpio); +} + +static struct platform_driver bd71828_gpio = { + .driver = { + .name = "bd71828-gpio" + }, + .probe = bd71828_probe, +}; + +module_platform_driver(bd71828_gpio); + +MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>"); +MODULE_DESCRIPTION("BD71828 voltage regulator driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:bd71828-gpio"); |