diff options
Diffstat (limited to 'drivers/gpio/wm831x-gpio.c')
| -rw-r--r-- | drivers/gpio/wm831x-gpio.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/drivers/gpio/wm831x-gpio.c b/drivers/gpio/wm831x-gpio.c new file mode 100644 index 00000000000..f9c09a54ec7 --- /dev/null +++ b/drivers/gpio/wm831x-gpio.c @@ -0,0 +1,252 @@ +/* + * wm831x-gpio.c -- gpiolib support for Wolfson WM831x PMICs + * + * 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/wm831x/core.h> +#include <linux/mfd/wm831x/pdata.h> +#include <linux/mfd/wm831x/gpio.h> + +#define WM831X_GPIO_MAX 16 + +struct wm831x_gpio { + struct wm831x *wm831x; + struct gpio_chip gpio_chip; +}; + +static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip) +{ + return container_of(chip, struct wm831x_gpio, gpio_chip); +} + +static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset) +{ + struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip); + struct wm831x *wm831x = wm831x_gpio->wm831x; + + return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset, + WM831X_GPN_DIR | WM831X_GPN_TRI, + WM831X_GPN_DIR); +} + +static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip); + struct wm831x *wm831x = wm831x_gpio->wm831x; + int ret; + + ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL); + if (ret < 0) + return ret; + + if (ret & 1 << offset) + return 1; + else + return 0; +} + +static int wm831x_gpio_direction_out(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip); + struct wm831x *wm831x = wm831x_gpio->wm831x; + + return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset, + WM831X_GPN_DIR | WM831X_GPN_TRI, 0); +} + +static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip); + struct wm831x *wm831x = wm831x_gpio->wm831x; + + wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset, + value << offset); +} + +#ifdef CONFIG_DEBUG_FS +static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) +{ + struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip); + struct wm831x *wm831x = wm831x_gpio->wm831x; + int i; + + for (i = 0; i < chip->ngpio; i++) { + int gpio = i + chip->base; + int reg; + const char *label, *pull, *powerdomain; + + /* 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 = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i); + if (reg < 0) { + dev_err(wm831x->dev, + "GPIO control %d read failed: %d\n", + gpio, reg); + seq_printf(s, "\n"); + continue; + } + + switch (reg & WM831X_GPN_PULL_MASK) { + case WM831X_GPIO_PULL_NONE: + pull = "nopull"; + break; + case WM831X_GPIO_PULL_DOWN: + pull = "pulldown"; + break; + case WM831X_GPIO_PULL_UP: + pull = "pullup"; + default: + pull = "INVALID PULL"; + break; + } + + switch (i + 1) { + case 1 ... 3: + case 7 ... 9: + if (reg & WM831X_GPN_PWR_DOM) + powerdomain = "VPMIC"; + else + powerdomain = "DBVDD"; + break; + + case 4 ... 6: + case 10 ... 12: + if (reg & WM831X_GPN_PWR_DOM) + powerdomain = "SYSVDD"; + else + powerdomain = "DBVDD"; + break; + + case 13 ... 16: + powerdomain = "TPVDD"; + break; + + default: + BUG(); + break; + } + + seq_printf(s, " %s %s %s %s%s\n" + " %s%s (0x%4x)\n", + reg & WM831X_GPN_DIR ? "in" : "out", + wm831x_gpio_get(chip, i) ? "high" : "low", + pull, + powerdomain, + reg & WM831X_GPN_POL ? " inverted" : "", + reg & WM831X_GPN_OD ? "open-drain" : "CMOS", + reg & WM831X_GPN_TRI ? " tristated" : "", + reg); + } +} +#else +#define wm831x_gpio_dbg_show NULL +#endif + +static struct gpio_chip template_chip = { + .label = "wm831x", + .owner = THIS_MODULE, + .direction_input = wm831x_gpio_direction_in, + .get = wm831x_gpio_get, + .direction_output = wm831x_gpio_direction_out, + .set = wm831x_gpio_set, + .dbg_show = wm831x_gpio_dbg_show, + .can_sleep = 1, +}; + +static int __devinit wm831x_gpio_probe(struct platform_device *pdev) +{ + struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); + struct wm831x_pdata *pdata = wm831x->dev->platform_data; + struct wm831x_gpio *wm831x_gpio; + int ret; + + wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL); + if (wm831x_gpio == NULL) + return -ENOMEM; + + wm831x_gpio->wm831x = wm831x; + wm831x_gpio->gpio_chip = template_chip; + wm831x_gpio->gpio_chip.ngpio = WM831X_GPIO_MAX; + wm831x_gpio->gpio_chip.dev = &pdev->dev; + if (pdata && pdata->gpio_base) + wm831x_gpio->gpio_chip.base = pdata->gpio_base; + else + wm831x_gpio->gpio_chip.base = -1; + + ret = gpiochip_add(&wm831x_gpio->gpio_chip); + if (ret < 0) { + dev_err(&pdev->dev, "Could not register gpiochip, %d\n", + ret); + goto err; + } + + platform_set_drvdata(pdev, wm831x_gpio); + + return ret; + +err: + kfree(wm831x_gpio); + return ret; +} + +static int __devexit wm831x_gpio_remove(struct platform_device *pdev) +{ + struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev); + int ret; + + ret = gpiochip_remove(&wm831x_gpio->gpio_chip); + if (ret == 0) + kfree(wm831x_gpio); + + return ret; +} + +static struct platform_driver wm831x_gpio_driver = { + .driver.name = "wm831x-gpio", + .driver.owner = THIS_MODULE, + .probe = wm831x_gpio_probe, + .remove = __devexit_p(wm831x_gpio_remove), +}; + +static int __init wm831x_gpio_init(void) +{ + return platform_driver_register(&wm831x_gpio_driver); +} +subsys_initcall(wm831x_gpio_init); + +static void __exit wm831x_gpio_exit(void) +{ + platform_driver_unregister(&wm831x_gpio_driver); +} +module_exit(wm831x_gpio_exit); + +MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); +MODULE_DESCRIPTION("GPIO interface for WM831x PMICs"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:wm831x-gpio"); |