diff options
Diffstat (limited to 'drivers/gpio/gpio-arizona.c')
| -rw-r--r-- | drivers/gpio/gpio-arizona.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-arizona.c b/drivers/gpio/gpio-arizona.c new file mode 100644 index 000000000..c6cf27003 --- /dev/null +++ b/drivers/gpio/gpio-arizona.c @@ -0,0 +1,218 @@ +/* + * gpiolib support for Wolfson Arizona class devices + * + * Copyright 2012 Wolfson Microelectronics PLC. + * + * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/gpio/driver.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/seq_file.h> + +#include <linux/mfd/arizona/core.h> +#include <linux/mfd/arizona/pdata.h> +#include <linux/mfd/arizona/registers.h> + +struct arizona_gpio { + struct arizona *arizona; + struct gpio_chip gpio_chip; +}; + +static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset) +{ + struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip); + struct arizona *arizona = arizona_gpio->arizona; + bool persistent = gpiochip_line_is_persistent(chip, offset); + bool change; + int ret; + + ret = regmap_update_bits_check(arizona->regmap, + ARIZONA_GPIO1_CTRL + offset, + ARIZONA_GPN_DIR, ARIZONA_GPN_DIR, + &change); + if (ret < 0) + return ret; + + if (change && persistent) { + pm_runtime_mark_last_busy(chip->parent); + pm_runtime_put_autosuspend(chip->parent); + } + + return 0; +} + +static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip); + struct arizona *arizona = arizona_gpio->arizona; + unsigned int reg, val; + int ret; + + reg = ARIZONA_GPIO1_CTRL + offset; + ret = regmap_read(arizona->regmap, reg, &val); + if (ret < 0) + return ret; + + /* Resume to read actual registers for input pins */ + if (val & ARIZONA_GPN_DIR) { + ret = pm_runtime_get_sync(chip->parent); + if (ret < 0) { + dev_err(chip->parent, "Failed to resume: %d\n", ret); + pm_runtime_put_autosuspend(chip->parent); + return ret; + } + + /* Register is cached, drop it to ensure a physical read */ + ret = regcache_drop_region(arizona->regmap, reg, reg); + if (ret < 0) { + dev_err(chip->parent, "Failed to drop cache: %d\n", + ret); + pm_runtime_put_autosuspend(chip->parent); + return ret; + } + + ret = regmap_read(arizona->regmap, reg, &val); + if (ret < 0) { + pm_runtime_put_autosuspend(chip->parent); + return ret; + } + + pm_runtime_mark_last_busy(chip->parent); + pm_runtime_put_autosuspend(chip->parent); + } + + if (val & ARIZONA_GPN_LVL) + return 1; + else + return 0; +} + +static int arizona_gpio_direction_out(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip); + struct arizona *arizona = arizona_gpio->arizona; + bool persistent = gpiochip_line_is_persistent(chip, offset); + unsigned int val; + int ret; + + ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val); + if (ret < 0) + return ret; + + if ((val & ARIZONA_GPN_DIR) && persistent) { + ret = pm_runtime_get_sync(chip->parent); + if (ret < 0) { + dev_err(chip->parent, "Failed to resume: %d\n", ret); + pm_runtime_put(chip->parent); + return ret; + } + } + + if (value) + value = ARIZONA_GPN_LVL; + + return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, + ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value); +} + +static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip); + struct arizona *arizona = arizona_gpio->arizona; + + if (value) + value = ARIZONA_GPN_LVL; + + regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, + ARIZONA_GPN_LVL, value); +} + +static const struct gpio_chip template_chip = { + .label = "arizona", + .owner = THIS_MODULE, + .direction_input = arizona_gpio_direction_in, + .get = arizona_gpio_get, + .direction_output = arizona_gpio_direction_out, + .set = arizona_gpio_set, + .can_sleep = true, +}; + +static int arizona_gpio_probe(struct platform_device *pdev) +{ + struct arizona *arizona = dev_get_drvdata(pdev->dev.parent); + struct arizona_pdata *pdata = dev_get_platdata(arizona->dev); + struct arizona_gpio *arizona_gpio; + int ret; + + arizona_gpio = devm_kzalloc(&pdev->dev, sizeof(*arizona_gpio), + GFP_KERNEL); + if (!arizona_gpio) + return -ENOMEM; + + arizona_gpio->arizona = arizona; + arizona_gpio->gpio_chip = template_chip; + arizona_gpio->gpio_chip.parent = &pdev->dev; +#ifdef CONFIG_OF_GPIO + arizona_gpio->gpio_chip.of_node = arizona->dev->of_node; +#endif + + switch (arizona->type) { + case WM5102: + case WM5110: + case WM8280: + case WM8997: + case WM8998: + case WM1814: + arizona_gpio->gpio_chip.ngpio = 5; + break; + case WM1831: + case CS47L24: + arizona_gpio->gpio_chip.ngpio = 2; + break; + default: + dev_err(&pdev->dev, "Unknown chip variant %d\n", + arizona->type); + return -EINVAL; + } + + if (pdata && pdata->gpio_base) + arizona_gpio->gpio_chip.base = pdata->gpio_base; + else + arizona_gpio->gpio_chip.base = -1; + + pm_runtime_enable(&pdev->dev); + + ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip, + arizona_gpio); + if (ret < 0) { + dev_err(&pdev->dev, "Could not register gpiochip, %d\n", + ret); + return ret; + } + + return 0; +} + +static struct platform_driver arizona_gpio_driver = { + .driver.name = "arizona-gpio", + .probe = arizona_gpio_probe, +}; + +module_platform_driver(arizona_gpio_driver); + +MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); +MODULE_DESCRIPTION("GPIO interface for Arizona devices"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:arizona-gpio"); |