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linux-next/drivers/gpio/gpio-wm831x.c
Charles Keepax 9674a8dc5b gpio: wm831x: Add basic device tree support
Now the wm831x-core has basic DT support we can update this driver to
allow use of the GPIOs within a device tree system.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2017-03-23 11:45:55 +00:00

320 lines
7.7 KiB
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/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 int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
{
struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(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 = gpiochip_get_data(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 = gpiochip_get_data(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 = gpiochip_get_data(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 = gpiochip_get_data(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 wm831x *wm831x, unsigned offset,
unsigned debounce)
{
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);
}
static int wm831x_set_config(struct gpio_chip *chip, unsigned int offset,
unsigned long config)
{
struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
struct wm831x *wm831x = wm831x_gpio->wm831x;
int reg = WM831X_GPIO1_CONTROL + offset;
switch (pinconf_to_config_param(config)) {
case PIN_CONFIG_DRIVE_OPEN_DRAIN:
return wm831x_set_bits(wm831x, reg,
WM831X_GPN_OD_MASK, WM831X_GPN_OD);
case PIN_CONFIG_DRIVE_PUSH_PULL:
return wm831x_set_bits(wm831x, reg,
WM831X_GPN_OD_MASK, 0);
case PIN_CONFIG_INPUT_DEBOUNCE:
return wm831x_gpio_set_debounce(wm831x, offset,
pinconf_to_config_argument(config));
default:
break;
}
return -ENOTSUPP;
}
#ifdef CONFIG_DEBUG_FS
static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(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" : "push-pull",
tristated ? " tristated" : "",
reg);
}
}
#else
#define wm831x_gpio_dbg_show NULL
#endif
static const 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_config = wm831x_set_config,
.dbg_show = wm831x_gpio_dbg_show,
.can_sleep = true,
};
static int wm831x_gpio_probe(struct platform_device *pdev)
{
struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
struct wm831x_pdata *pdata = &wm831x->pdata;
struct wm831x_gpio *wm831x_gpio;
int ret;
wm831x_gpio = devm_kzalloc(&pdev->dev, 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.parent = &pdev->dev;
if (pdata && pdata->gpio_base)
wm831x_gpio->gpio_chip.base = pdata->gpio_base;
else
wm831x_gpio->gpio_chip.base = -1;
#ifdef CONFIG_OF_GPIO
wm831x_gpio->gpio_chip.of_node = wm831x->dev->of_node;
#endif
ret = devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip,
wm831x_gpio);
if (ret < 0) {
dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, wm831x_gpio);
return ret;
}
static struct platform_driver wm831x_gpio_driver = {
.driver.name = "wm831x-gpio",
.probe = wm831x_gpio_probe,
};
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");