kernel-ark/drivers/gpio/wm8994-gpio.c
Mark Brown 4b66672901 gpiolib: Add WM8958 support to the WM8994 driver
Several of the GPIOs on the WM8994 are fixed function on the WM8958 so
error out if the user tries to request them with gpiolib.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
2010-11-26 15:16:19 +00:00

243 lines
5.8 KiB
C

/*
* 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/slab.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_request(struct gpio_chip *chip, unsigned offset)
{
struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
struct wm8994 *wm8994 = wm8994_gpio->wm8994;
switch (wm8994->type) {
case WM8958:
switch (offset) {
case 1:
case 2:
case 3:
case 4:
case 6:
return -EINVAL;
}
break;
default:
break;
}
return 0;
}
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);
}
static int wm8994_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
struct wm8994 *wm8994 = wm8994_gpio->wm8994;
if (!wm8994->irq_base)
return -EINVAL;
return wm8994->irq_base + offset;
}
#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,
.request = wm8994_gpio_request,
.direction_input = wm8994_gpio_direction_in,
.get = wm8994_gpio_get,
.direction_output = wm8994_gpio_direction_out,
.set = wm8994_gpio_set,
.to_irq = wm8994_gpio_to_irq,
.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");