diff options
Diffstat (limited to 'drivers/gpio/wm8994-gpio.c')
| -rw-r--r-- | drivers/gpio/wm8994-gpio.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/gpio/wm8994-gpio.c b/drivers/gpio/wm8994-gpio.c new file mode 100644 index 000000000000..de28b4a470ea --- /dev/null +++ b/drivers/gpio/wm8994-gpio.c @@ -0,0 +1,204 @@ +/* + * wm8994-gpio.c -- gpiolib support for Wolfson WM8994 + * + * Copyright 2009 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/module.h> +#include <linux/gpio.h> +#include <linux/mfd/core.h> +#include <linux/platform_device.h> +#include <linux/seq_file.h> + +#include <linux/mfd/wm8994/core.h> +#include <linux/mfd/wm8994/pdata.h> +#include <linux/mfd/wm8994/gpio.h> +#include <linux/mfd/wm8994/registers.h> + +struct wm8994_gpio { + struct wm8994 *wm8994; + struct gpio_chip gpio_chip; +}; + +static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip) +{ + return container_of(chip, struct wm8994_gpio, gpio_chip); +} + +static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset) +{ + struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); + struct wm8994 *wm8994 = wm8994_gpio->wm8994; + + return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, + WM8994_GPN_DIR, WM8994_GPN_DIR); +} + +static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); + struct wm8994 *wm8994 = wm8994_gpio->wm8994; + int ret; + + ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset); + if (ret < 0) + return ret; + + if (ret & WM8994_GPN_LVL) + return 1; + else + return 0; +} + +static int wm8994_gpio_direction_out(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); + struct wm8994 *wm8994 = wm8994_gpio->wm8994; + + return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, + WM8994_GPN_DIR, 0); +} + +static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); + struct wm8994 *wm8994 = wm8994_gpio->wm8994; + + if (value) + value = WM8994_GPN_LVL; + + wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value); +} + +#ifdef CONFIG_DEBUG_FS +static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) +{ + struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); + struct wm8994 *wm8994 = wm8994_gpio->wm8994; + int i; + + for (i = 0; i < chip->ngpio; i++) { + int gpio = i + chip->base; + int reg; + const char *label; + + /* We report the GPIO even if it's not requested since + * we're also reporting things like alternate + * functions which apply even when the GPIO is not in + * use as a GPIO. + */ + label = gpiochip_is_requested(chip, i); + if (!label) + label = "Unrequested"; + + seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label); + + reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i); + if (reg < 0) { + dev_err(wm8994->dev, + "GPIO control %d read failed: %d\n", + gpio, reg); + seq_printf(s, "\n"); + continue; + } + + /* No decode yet; note that GPIO2 is special */ + seq_printf(s, "(%x)\n", reg); + } +} +#else +#define wm8994_gpio_dbg_show NULL +#endif + +static struct gpio_chip template_chip = { + .label = "wm8994", + .owner = THIS_MODULE, + .direction_input = wm8994_gpio_direction_in, + .get = wm8994_gpio_get, + .direction_output = wm8994_gpio_direction_out, + .set = wm8994_gpio_set, + .dbg_show = wm8994_gpio_dbg_show, + .can_sleep = 1, +}; + +static int __devinit wm8994_gpio_probe(struct platform_device *pdev) +{ + struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent); + struct wm8994_pdata *pdata = wm8994->dev->platform_data; + struct wm8994_gpio *wm8994_gpio; + int ret; + + wm8994_gpio = kzalloc(sizeof(*wm8994_gpio), GFP_KERNEL); + if (wm8994_gpio == NULL) + return -ENOMEM; + + wm8994_gpio->wm8994 = wm8994; + wm8994_gpio->gpio_chip = template_chip; + wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX; + wm8994_gpio->gpio_chip.dev = &pdev->dev; + if (pdata && pdata->gpio_base) + wm8994_gpio->gpio_chip.base = pdata->gpio_base; + else + wm8994_gpio->gpio_chip.base = -1; + + ret = gpiochip_add(&wm8994_gpio->gpio_chip); + if (ret < 0) { + dev_err(&pdev->dev, "Could not register gpiochip, %d\n", + ret); + goto err; + } + + platform_set_drvdata(pdev, wm8994_gpio); + + return ret; + +err: + kfree(wm8994_gpio); + return ret; +} + +static int __devexit wm8994_gpio_remove(struct platform_device *pdev) +{ + struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev); + int ret; + + ret = gpiochip_remove(&wm8994_gpio->gpio_chip); + if (ret == 0) + kfree(wm8994_gpio); + + return ret; +} + +static struct platform_driver wm8994_gpio_driver = { + .driver.name = "wm8994-gpio", + .driver.owner = THIS_MODULE, + .probe = wm8994_gpio_probe, + .remove = __devexit_p(wm8994_gpio_remove), +}; + +static int __init wm8994_gpio_init(void) +{ + return platform_driver_register(&wm8994_gpio_driver); +} +subsys_initcall(wm8994_gpio_init); + +static void __exit wm8994_gpio_exit(void) +{ + platform_driver_unregister(&wm8994_gpio_driver); +} +module_exit(wm8994_gpio_exit); + +MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); +MODULE_DESCRIPTION("GPIO interface for WM8994"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:wm8994-gpio"); |