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linux/drivers/gpio/gpio-wm8994.c
Mark Brown 8cd578b6e2 gpiolib: wm8994: Pay attention to the value set when enabling as output 
Not paying attention to the value being set is a bad thing because it
means that we'll not set the hardware up to reflect what was requested.
Not setting the hardware up to reflect what was requested means that the
caller won't get the results they wanted.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-07-05 14:49:10 +02:00

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7.5 KiB
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/*
* 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;
if (value)
value = WM8994_GPN_LVL;
return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
WM8994_GPN_DIR | WM8994_GPN_LVL, value);
}
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 const char *wm8994_gpio_fn(u16 fn)
{
switch (fn) {
case WM8994_GP_FN_PIN_SPECIFIC:
return "pin-specific";
case WM8994_GP_FN_GPIO:
return "GPIO";
case WM8994_GP_FN_SDOUT:
return "SDOUT";
case WM8994_GP_FN_IRQ:
return "IRQ";
case WM8994_GP_FN_TEMPERATURE:
return "Temperature";
case WM8994_GP_FN_MICBIAS1_DET:
return "MICBIAS1 detect";
case WM8994_GP_FN_MICBIAS1_SHORT:
return "MICBIAS1 short";
case WM8994_GP_FN_MICBIAS2_DET:
return "MICBIAS2 detect";
case WM8994_GP_FN_MICBIAS2_SHORT:
return "MICBIAS2 short";
case WM8994_GP_FN_FLL1_LOCK:
return "FLL1 lock";
case WM8994_GP_FN_FLL2_LOCK:
return "FLL2 lock";
case WM8994_GP_FN_SRC1_LOCK:
return "SRC1 lock";
case WM8994_GP_FN_SRC2_LOCK:
return "SRC2 lock";
case WM8994_GP_FN_DRC1_ACT:
return "DRC1 activity";
case WM8994_GP_FN_DRC2_ACT:
return "DRC2 activity";
case WM8994_GP_FN_DRC3_ACT:
return "DRC3 activity";
case WM8994_GP_FN_WSEQ_STATUS:
return "Write sequencer";
case WM8994_GP_FN_FIFO_ERROR:
return "FIFO error";
case WM8994_GP_FN_OPCLK:
return "OPCLK";
case WM8994_GP_FN_THW:
return "Thermal warning";
case WM8994_GP_FN_DCS_DONE:
return "DC servo";
case WM8994_GP_FN_FLL1_OUT:
return "FLL1 output";
case WM8994_GP_FN_FLL2_OUT:
return "FLL1 output";
default:
return "Unknown";
}
}
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;
}
if (reg & WM8994_GPN_DIR)
seq_printf(s, "in ");
else
seq_printf(s, "out ");
if (reg & WM8994_GPN_PU)
seq_printf(s, "pull up ");
if (reg & WM8994_GPN_PD)
seq_printf(s, "pull down ");
if (reg & WM8994_GPN_POL)
seq_printf(s, "inverted ");
else
seq_printf(s, "noninverted ");
if (reg & WM8994_GPN_OP_CFG)
seq_printf(s, "open drain ");
else
seq_printf(s, "CMOS ");
seq_printf(s, "%s (%x)\n",
wm8994_gpio_fn(reg & WM8994_GPN_FN_MASK), 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");
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