gpio-madera.c
// SPDX-License-Identifier: GPL-2.0
/*
* GPIO support for Cirrus Logic Madera codecs
*
* Copyright (C) 2015-2018 Cirrus Logic
*
* 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; version 2.
*/
#include <linux/gpio/driver.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mfd/madera/core.h>
#include <linux/mfd/madera/pdata.h>
#include <linux/mfd/madera/registers.h>
struct madera_gpio {
struct madera *madera;
/* storage space for the gpio_chip we're using */
struct gpio_chip gpio_chip;
};
static int madera_gpio_get_direction(struct gpio_chip *chip,
unsigned int offset)
{
struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
struct madera *madera = madera_gpio->madera;
unsigned int reg_offset = 2 * offset;
unsigned int val;
int ret;
ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_2 + reg_offset,
&val);
if (ret < 0)
return ret;
return !!(val & MADERA_GP1_DIR_MASK);
}
static int madera_gpio_direction_in(struct gpio_chip *chip, unsigned int offset)
{
struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
struct madera *madera = madera_gpio->madera;
unsigned int reg_offset = 2 * offset;
return regmap_update_bits(madera->regmap,
MADERA_GPIO1_CTRL_2 + reg_offset,
MADERA_GP1_DIR_MASK, MADERA_GP1_DIR);
}
static int madera_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
struct madera *madera = madera_gpio->madera;
unsigned int reg_offset = 2 * offset;
unsigned int val;
int ret;
ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_1 + reg_offset,
&val);
if (ret < 0)
return ret;
return !!(val & MADERA_GP1_LVL_MASK);
}
static int madera_gpio_direction_out(struct gpio_chip *chip,
unsigned int offset, int value)
{
struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
struct madera *madera = madera_gpio->madera;
unsigned int reg_offset = 2 * offset;
unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
int ret;
ret = regmap_update_bits(madera->regmap,
MADERA_GPIO1_CTRL_2 + reg_offset,
MADERA_GP1_DIR_MASK, 0);
if (ret < 0)
return ret;
return regmap_update_bits(madera->regmap,
MADERA_GPIO1_CTRL_1 + reg_offset,
MADERA_GP1_LVL_MASK, reg_val);
}
static void madera_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
struct madera *madera = madera_gpio->madera;
unsigned int reg_offset = 2 * offset;
unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
int ret;
ret = regmap_update_bits(madera->regmap,
MADERA_GPIO1_CTRL_1 + reg_offset,
MADERA_GP1_LVL_MASK, reg_val);
/* set() doesn't return an error so log a warning */
if (ret)
dev_warn(madera->dev, "Failed to write to 0x%x (%d)\n",
MADERA_GPIO1_CTRL_1 + reg_offset, ret);
}
static const struct gpio_chip madera_gpio_chip = {
.label = "madera",
.owner = THIS_MODULE,
.request = gpiochip_generic_request,
.free = gpiochip_generic_free,
.get_direction = madera_gpio_get_direction,
.direction_input = madera_gpio_direction_in,
.get = madera_gpio_get,
.direction_output = madera_gpio_direction_out,
.set = madera_gpio_set,
.set_config = gpiochip_generic_config,
.can_sleep = true,
};
static int madera_gpio_probe(struct platform_device *pdev)
{
struct madera *madera = dev_get_drvdata(pdev->dev.parent);
struct madera_pdata *pdata = dev_get_platdata(madera->dev);
struct madera_gpio *madera_gpio;
int ret;
madera_gpio = devm_kzalloc(&pdev->dev, sizeof(*madera_gpio),
GFP_KERNEL);
if (!madera_gpio)
return -ENOMEM;
madera_gpio->madera = madera;
/* Construct suitable gpio_chip from the template in madera_gpio_chip */
madera_gpio->gpio_chip = madera_gpio_chip;
madera_gpio->gpio_chip.parent = pdev->dev.parent;
switch (madera->type) {
case CS47L35:
madera_gpio->gpio_chip.ngpio = CS47L35_NUM_GPIOS;
break;
case CS47L85:
case WM1840:
madera_gpio->gpio_chip.ngpio = CS47L85_NUM_GPIOS;
break;
case CS47L90:
case CS47L91:
madera_gpio->gpio_chip.ngpio = CS47L90_NUM_GPIOS;
break;
default:
dev_err(&pdev->dev, "Unknown chip variant %d\n", madera->type);
return -EINVAL;
}
/* We want to be usable on systems that don't use devicetree or acpi */
if (pdata && pdata->gpio_base)
madera_gpio->gpio_chip.base = pdata->gpio_base;
else
madera_gpio->gpio_chip.base = -1;
ret = devm_gpiochip_add_data(&pdev->dev,
&madera_gpio->gpio_chip,
madera_gpio);
if (ret < 0) {
dev_dbg(&pdev->dev, "Could not register gpiochip, %d\n", ret);
return ret;
}
/*
* This is part of a composite MFD device which can only be used with
* the corresponding pinctrl driver. On all supported silicon the GPIO
* to pinctrl mapping is fixed in the silicon, so we register it
* explicitly instead of requiring a redundant gpio-ranges in the
* devicetree.
* In any case we also want to work on systems that don't use devicetree
* or acpi.
*/
ret = gpiochip_add_pin_range(&madera_gpio->gpio_chip, "madera-pinctrl",
0, 0, madera_gpio->gpio_chip.ngpio);
if (ret) {
dev_dbg(&pdev->dev, "Failed to add pin range (%d)\n", ret);
return ret;
}
return 0;
}
static struct platform_driver madera_gpio_driver = {
.driver = {
.name = "madera-gpio",
},
.probe = madera_gpio_probe,
};
module_platform_driver(madera_gpio_driver);
MODULE_SOFTDEP("pre: pinctrl-madera");
MODULE_DESCRIPTION("GPIO interface for Madera codecs");
MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>");
MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:madera-gpio");