diff options
Diffstat (limited to 'drivers/gpio/gpio-bd70528.c')
| -rw-r--r-- | drivers/gpio/gpio-bd70528.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-bd70528.c b/drivers/gpio/gpio-bd70528.c new file mode 100644 index 000000000000..fd85605d2dab --- /dev/null +++ b/drivers/gpio/gpio-bd70528.c @@ -0,0 +1,232 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2018 ROHM Semiconductors +// gpio-bd70528.c ROHM BD70528MWV gpio driver + +#include <linux/gpio/driver.h> +#include <linux/mfd/rohm-bd70528.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#define GPIO_IN_REG(offset) (BD70528_REG_GPIO1_IN + (offset) * 2) +#define GPIO_OUT_REG(offset) (BD70528_REG_GPIO1_OUT + (offset) * 2) + +struct bd70528_gpio { + struct rohm_regmap_dev chip; + struct gpio_chip gpio; +}; + +static int bd70528_set_debounce(struct bd70528_gpio *bdgpio, + unsigned int offset, unsigned int debounce) +{ + u8 val; + + switch (debounce) { + case 0: + val = BD70528_DEBOUNCE_DISABLE; + break; + case 1 ... 15: + val = BD70528_DEBOUNCE_15MS; + break; + case 16 ... 30: + val = BD70528_DEBOUNCE_30MS; + break; + case 31 ... 50: + val = BD70528_DEBOUNCE_50MS; + break; + default: + dev_err(bdgpio->chip.dev, + "Invalid debouce value %u\n", debounce); + return -EINVAL; + } + return regmap_update_bits(bdgpio->chip.regmap, GPIO_IN_REG(offset), + BD70528_DEBOUNCE_MASK, val); +} + +static int bd70528_get_direction(struct gpio_chip *chip, unsigned int offset) +{ + struct bd70528_gpio *bdgpio = gpiochip_get_data(chip); + int val, ret; + + /* Do we need to do something to IRQs here? */ + ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset), &val); + if (ret) { + dev_err(bdgpio->chip.dev, "Could not read gpio direction\n"); + return ret; + } + + return !(val & BD70528_GPIO_OUT_EN_MASK); +} + +static int bd70528_gpio_set_config(struct gpio_chip *chip, unsigned int offset, + unsigned long config) +{ + struct bd70528_gpio *bdgpio = gpiochip_get_data(chip); + + switch (pinconf_to_config_param(config)) { + case PIN_CONFIG_DRIVE_OPEN_DRAIN: + return regmap_update_bits(bdgpio->chip.regmap, + GPIO_OUT_REG(offset), + BD70528_GPIO_DRIVE_MASK, + BD70528_GPIO_OPEN_DRAIN); + break; + case PIN_CONFIG_DRIVE_PUSH_PULL: + return regmap_update_bits(bdgpio->chip.regmap, + GPIO_OUT_REG(offset), + BD70528_GPIO_DRIVE_MASK, + BD70528_GPIO_PUSH_PULL); + break; + case PIN_CONFIG_INPUT_DEBOUNCE: + return bd70528_set_debounce(bdgpio, offset, + pinconf_to_config_argument(config)); + break; + default: + break; + } + return -ENOTSUPP; +} + +static int bd70528_direction_input(struct gpio_chip *chip, unsigned int offset) +{ + struct bd70528_gpio *bdgpio = gpiochip_get_data(chip); + + /* Do we need to do something to IRQs here? */ + return regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset), + BD70528_GPIO_OUT_EN_MASK, + BD70528_GPIO_OUT_DISABLE); +} + +static void bd70528_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + int ret; + struct bd70528_gpio *bdgpio = gpiochip_get_data(chip); + u8 val = (value) ? BD70528_GPIO_OUT_HI : BD70528_GPIO_OUT_LO; + + ret = regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset), + BD70528_GPIO_OUT_MASK, val); + if (ret) + dev_err(bdgpio->chip.dev, "Could not set gpio to %d\n", value); +} + +static int bd70528_direction_output(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct bd70528_gpio *bdgpio = gpiochip_get_data(chip); + + bd70528_gpio_set(chip, offset, value); + return regmap_update_bits(bdgpio->chip.regmap, GPIO_OUT_REG(offset), + BD70528_GPIO_OUT_EN_MASK, + BD70528_GPIO_OUT_ENABLE); +} + +#define GPIO_IN_STATE_MASK(offset) (BD70528_GPIO_IN_STATE_BASE << (offset)) + +static int bd70528_gpio_get_o(struct bd70528_gpio *bdgpio, unsigned int offset) +{ + int ret; + unsigned int val; + + ret = regmap_read(bdgpio->chip.regmap, GPIO_OUT_REG(offset), &val); + if (!ret) + ret = !!(val & BD70528_GPIO_OUT_MASK); + else + dev_err(bdgpio->chip.dev, "GPIO (out) state read failed\n"); + + return ret; +} + +static int bd70528_gpio_get_i(struct bd70528_gpio *bdgpio, unsigned int offset) +{ + unsigned int val; + int ret; + + ret = regmap_read(bdgpio->chip.regmap, BD70528_REG_GPIO_STATE, &val); + + if (!ret) + ret = !(val & GPIO_IN_STATE_MASK(offset)); + else + dev_err(bdgpio->chip.dev, "GPIO (in) state read failed\n"); + + return ret; +} + +static int bd70528_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + int ret = -EINVAL; + struct bd70528_gpio *bdgpio = gpiochip_get_data(chip); + + /* + * There is a race condition where someone might be changing the + * GPIO direction after we get it but before we read the value. But + * application design where GPIO direction may be changed just when + * we read GPIO value would be pointless as reader could not know + * whether the returned high/low state is caused by input or output. + * Or then there must be other ways to mitigate the issue. Thus + * locking would make no sense. + */ + ret = bd70528_get_direction(chip, offset); + if (ret == 0) + ret = bd70528_gpio_get_o(bdgpio, offset); + else if (ret == 1) + ret = bd70528_gpio_get_i(bdgpio, offset); + else + dev_err(bdgpio->chip.dev, "failed to read GPIO direction\n"); + + return ret; +} + +static int bd70528_probe(struct platform_device *pdev) +{ + struct bd70528_gpio *bdgpio; + struct rohm_regmap_dev *bd70528; + int ret; + + bd70528 = dev_get_drvdata(pdev->dev.parent); + if (!bd70528) { + dev_err(&pdev->dev, "No MFD driver data\n"); + return -EINVAL; + } + + bdgpio = devm_kzalloc(&pdev->dev, sizeof(*bdgpio), + GFP_KERNEL); + if (!bdgpio) + return -ENOMEM; + bdgpio->chip.dev = &pdev->dev; + bdgpio->gpio.parent = pdev->dev.parent; + bdgpio->gpio.label = "bd70528-gpio"; + bdgpio->gpio.owner = THIS_MODULE; + bdgpio->gpio.get_direction = bd70528_get_direction; + bdgpio->gpio.direction_input = bd70528_direction_input; + bdgpio->gpio.direction_output = bd70528_direction_output; + bdgpio->gpio.set_config = bd70528_gpio_set_config; + bdgpio->gpio.can_sleep = true; + bdgpio->gpio.get = bd70528_gpio_get; + bdgpio->gpio.set = bd70528_gpio_set; + bdgpio->gpio.ngpio = 4; + bdgpio->gpio.base = -1; +#ifdef CONFIG_OF_GPIO + bdgpio->gpio.of_node = pdev->dev.parent->of_node; +#endif + bdgpio->chip.regmap = bd70528->regmap; + + ret = devm_gpiochip_add_data(&pdev->dev, &bdgpio->gpio, + bdgpio); + if (ret) + dev_err(&pdev->dev, "gpio_init: Failed to add bd70528-gpio\n"); + + return ret; +} + +static struct platform_driver bd70528_gpio = { + .driver = { + .name = "bd70528-gpio" + }, + .probe = bd70528_probe, +}; + +module_platform_driver(bd70528_gpio); + +MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>"); +MODULE_DESCRIPTION("BD70528 voltage regulator driver"); +MODULE_LICENSE("GPL"); |