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// SPDX-License-Identifier: GPL-2.0-only
/*
* regmap based generic GPIO driver
*
* Copyright 2020 Michael Walle <michael@walle.cc>
*/
#include <linux/gpio/driver.h>
#include <linux/gpio/regmap.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regmap.h>
struct gpio_regmap {
struct device *parent;
struct regmap *regmap;
struct gpio_chip gpio_chip;
int reg_stride;
int ngpio_per_reg;
unsigned int reg_dat_base;
unsigned int reg_set_base;
unsigned int reg_clr_base;
unsigned int reg_dir_in_base;
unsigned int reg_dir_out_base;
int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
unsigned int offset, unsigned int *reg,
unsigned int *mask);
void *driver_data;
};
static unsigned int gpio_regmap_addr(unsigned int addr)
{
if (addr == GPIO_REGMAP_ADDR_ZERO)
return 0;
return addr;
}
static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
unsigned int base, unsigned int offset,
unsigned int *reg, unsigned int *mask)
{
unsigned int line = offset % gpio->ngpio_per_reg;
unsigned int stride = offset / gpio->ngpio_per_reg;
*reg = base + stride * gpio->reg_stride;
*mask = BIT(line);
return 0;
}
static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
{
struct gpio_regmap *gpio = gpiochip_get_data(chip);
unsigned int base, val, reg, mask;
int ret;
/* we might not have an output register if we are input only */
if (gpio->reg_dat_base)
base = gpio_regmap_addr(gpio->reg_dat_base);
else
base = gpio_regmap_addr(gpio->reg_set_base);
ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
if (ret)
return ret;
ret = regmap_read(gpio->regmap, reg, &val);
if (ret)
return ret;
return !!(val & mask);
}
static void gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
int val)
{
struct gpio_regmap *gpio = gpiochip_get_data(chip);
unsigned int base = gpio_regmap_addr(gpio->reg_set_base);
unsigned int reg, mask;
gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
if (val)
regmap_update_bits(gpio->regmap, reg, mask, mask);
else
regmap_update_bits(gpio->regmap, reg, mask, 0);
}
static void gpio_regmap_set_with_clear(struct gpio_chip *chip,
unsigned int offset, int val)
{
struct gpio_regmap *gpio = gpiochip_get_data(chip);
unsigned int base, reg, mask;
if (val)
base = gpio_regmap_addr(gpio->reg_set_base);
else
base = gpio_regmap_addr(gpio->reg_clr_base);
gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
regmap_write(gpio->regmap, reg, mask);
}
static int gpio_regmap_get_direction(struct gpio_chip *chip,
unsigned int offset)
{
struct gpio_regmap *gpio = gpiochip_get_data(chip);
unsigned int base, val, reg, mask;
int invert, ret;
if (gpio->reg_dir_out_base) {
base = gpio_regmap_addr(gpio->reg_dir_out_base);
invert = 0;
} else if (gpio->reg_dir_in_base) {
base = gpio_regmap_addr(gpio->reg_dir_in_base);
invert = 1;
} else {
return -EOPNOTSUPP;
}
ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
if (ret)
return ret;
ret = regmap_read(gpio->regmap, reg, &val);
if (ret)
return ret;
if (!!(val & mask) ^ invert)
return GPIO_LINE_DIRECTION_OUT;
else
return GPIO_LINE_DIRECTION_IN;
}
static int gpio_regmap_set_direction(struct gpio_chip *chip,
unsigned int offset, bool output)
{
struct gpio_regmap *gpio = gpiochip_get_data(chip);
unsigned int base, val, reg, mask;
int invert, ret;
if (gpio->reg_dir_out_base) {
base = gpio_regmap_addr(gpio->reg_dir_out_base);
invert = 0;
} else if (gpio->reg_dir_in_base) {
base = gpio_regmap_addr(gpio->reg_dir_in_base);
invert = 1;
} else {
return -EOPNOTSUPP;
}
ret = gpio->reg_mask_xlate(gpio, base, offset, &reg, &mask);
if (ret)
return ret;
if (invert)
val = output ? 0 : mask;
else
val = output ? mask : 0;
return regmap_update_bits(gpio->regmap, reg, mask, val);
}
static int gpio_regmap_direction_input(struct gpio_chip *chip,
unsigned int offset)
{
return gpio_regmap_set_direction(chip, offset, false);
}
static int gpio_regmap_direction_output(struct gpio_chip *chip,
unsigned int offset, int value)
{
gpio_regmap_set(chip, offset, value);
return gpio_regmap_set_direction(chip, offset, true);
}
void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio)
{
return gpio->driver_data;
}
EXPORT_SYMBOL_GPL(gpio_regmap_get_drvdata);
/**
* gpio_regmap_register() - Register a generic regmap GPIO controller
* @config: configuration for gpio_regmap
*
* Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
*/
struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config)
{
struct gpio_regmap *gpio;
struct gpio_chip *chip;
int ret;
if (!config->parent)
return ERR_PTR(-EINVAL);
if (!config->ngpio)
return ERR_PTR(-EINVAL);
/* we need at least one */
if (!config->reg_dat_base && !config->reg_set_base)
return ERR_PTR(-EINVAL);
/* if we have a direction register we need both input and output */
if ((config->reg_dir_out_base || config->reg_dir_in_base) &&
(!config->reg_dat_base || !config->reg_set_base))
return ERR_PTR(-EINVAL);
/* we don't support having both registers simultaneously for now */
if (config->reg_dir_out_base && config->reg_dir_in_base)
return ERR_PTR(-EINVAL);
gpio = kzalloc(sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return ERR_PTR(-ENOMEM);
gpio->parent = config->parent;
gpio->driver_data = config->drvdata;
gpio->regmap = config->regmap;
gpio->ngpio_per_reg = config->ngpio_per_reg;
gpio->reg_stride = config->reg_stride;
gpio->reg_mask_xlate = config->reg_mask_xlate;
gpio->reg_dat_base = config->reg_dat_base;
gpio->reg_set_base = config->reg_set_base;
gpio->reg_clr_base = config->reg_clr_base;
gpio->reg_dir_in_base = config->reg_dir_in_base;
gpio->reg_dir_out_base = config->reg_dir_out_base;
/* if not set, assume there is only one register */
if (!gpio->ngpio_per_reg)
gpio->ngpio_per_reg = config->ngpio;
/* if not set, assume they are consecutive */
if (!gpio->reg_stride)
gpio->reg_stride = 1;
if (!gpio->reg_mask_xlate)
gpio->reg_mask_xlate = gpio_regmap_simple_xlate;
chip = &gpio->gpio_chip;
chip->parent = config->parent;
chip->fwnode = config->fwnode;
chip->base = -1;
chip->ngpio = config->ngpio;
chip->names = config->names;
chip->label = config->label ?: dev_name(config->parent);
/*
* If our regmap is fast_io we should probably set can_sleep to false.
* Right now, the regmap doesn't save this property, nor is there any
* access function for it.
* The only regmap type which uses fast_io is regmap-mmio. For now,
* assume a safe default of true here.
*/
chip->can_sleep = true;
chip->get = gpio_regmap_get;
if (gpio->reg_set_base && gpio->reg_clr_base)
chip->set = gpio_regmap_set_with_clear;
else if (gpio->reg_set_base)
chip->set = gpio_regmap_set;
if (gpio->reg_dir_in_base || gpio->reg_dir_out_base) {
chip->get_direction = gpio_regmap_get_direction;
chip->direction_input = gpio_regmap_direction_input;
chip->direction_output = gpio_regmap_direction_output;
}
ret = gpiochip_add_data(chip, gpio);
if (ret < 0)
goto err_free_gpio;
if (config->irq_domain) {
ret = gpiochip_irqchip_add_domain(chip, config->irq_domain);
if (ret)
goto err_remove_gpiochip;
}
return gpio;
err_remove_gpiochip:
gpiochip_remove(chip);
err_free_gpio:
kfree(gpio);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(gpio_regmap_register);
/**
* gpio_regmap_unregister() - Unregister a generic regmap GPIO controller
* @gpio: gpio_regmap device to unregister
*/
void gpio_regmap_unregister(struct gpio_regmap *gpio)
{
gpiochip_remove(&gpio->gpio_chip);
kfree(gpio);
}
EXPORT_SYMBOL_GPL(gpio_regmap_unregister);
static void devm_gpio_regmap_unregister(void *res)
{
gpio_regmap_unregister(res);
}
/**
* devm_gpio_regmap_register() - resource managed gpio_regmap_register()
* @dev: device that is registering this GPIO device
* @config: configuration for gpio_regmap
*
* Managed gpio_regmap_register(). For generic regmap GPIO device registered by
* this function, gpio_regmap_unregister() is automatically called on driver
* detach. See gpio_regmap_register() for more information.
*
* Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
*/
struct gpio_regmap *devm_gpio_regmap_register(struct device *dev,
const struct gpio_regmap_config *config)
{
struct gpio_regmap *gpio;
int ret;
gpio = gpio_regmap_register(config);
if (IS_ERR(gpio))
return gpio;
ret = devm_add_action_or_reset(dev, devm_gpio_regmap_unregister, gpio);
if (ret)
return ERR_PTR(ret);
return gpio;
}
EXPORT_SYMBOL_GPL(devm_gpio_regmap_register);
MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
MODULE_DESCRIPTION("GPIO generic regmap driver core");
MODULE_LICENSE("GPL");