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linux/drivers/gpio/gpio-wm831x.c
Mark Brown cd99758ba3 mfd: Convert wm831x to irq_domain 
The modern idiom is to use irq_domain to allocate interrupts. This is
useful partly to allow further infrastructure to be based on the domains
and partly because it makes it much easier to allocate virtual interrupts
to devices as we don't need to allocate a contiguous range of interrupt
numbers.

Convert the wm831x driver over to this infrastructure, using a legacy
IRQ mapping if an irq_base is specified in platform data and otherwise
using a linear mapping, always registering the interrupts even if they
won't ever be used. Only boards which need to use the GPIOs as
interrupts should need to use an irq_base.

This means that we can't use the MFD irq_base management since the
unless we're using an explicit irq_base from platform data we can't rely
on a linear mapping of interrupts.  Instead we need to map things via
the irq_domain - provide a conveniencem function wm831x_irq() to save a
small amount of typing when doing so. Looking at this I couldn't clearly
see anything the MFD core could do to make this nicer.

Since we're not supporting device tree yet there's no meaningful
advantage if we don't do this conversion in one, the fact that the
interrupt resources are used for repeated IP blocks makes accessor
functions for the irq_domain more trouble to do than they're worth.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
2012-05-20 17:27:07 +02:00

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/*
* 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/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/wm831x/core.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/mfd/wm831x/gpio.h>
#include <linux/mfd/wm831x/irq.h>
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;
int val = WM831X_GPN_DIR;
if (wm831x->has_gpio_ena)
val |= WM831X_GPN_TRI;
return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
WM831X_GPN_DIR | WM831X_GPN_TRI |
WM831X_GPN_FN_MASK, val);
}
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 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);
}
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;
int val = 0;
int ret;
if (wm831x->has_gpio_ena)
val |= WM831X_GPN_TRI;
ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
WM831X_GPN_DIR | WM831X_GPN_TRI |
WM831X_GPN_FN_MASK, val);
if (ret < 0)
return ret;
/* Can only set GPIO state once it's in output mode */
wm831x_gpio_set(chip, offset, value);
return 0;
}
static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
struct wm831x *wm831x = wm831x_gpio->wm831x;
return irq_create_mapping(wm831x->irq_domain,
WM831X_IRQ_GPIO_1 + offset);
}
static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
unsigned debounce)
{
struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
struct wm831x *wm831x = wm831x_gpio->wm831x;
int reg = WM831X_GPIO1_CONTROL + offset;
int ret, fn;
ret = wm831x_reg_read(wm831x, reg);
if (ret < 0)
return ret;
switch (ret & WM831X_GPN_FN_MASK) {
case 0:
case 1:
break;
default:
/* Not in GPIO mode */
return -EBUSY;
}
if (debounce >= 32 && debounce <= 64)
fn = 0;
else if (debounce >= 4000 && debounce <= 8000)
fn = 1;
else
return -EINVAL;
return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
}
#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, tristated;
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";
break;
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;
}
tristated = reg & WM831X_GPN_TRI;
if (wm831x->has_gpio_ena)
tristated = !tristated;
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",
tristated ? " 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,
.to_irq = wm831x_gpio_to_irq,
.set_debounce = wm831x_gpio_set_debounce,
.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->num_gpio;
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");
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