149 lines
3.2 KiB
C
149 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Driver for PCA9570 I2C GPO expander
|
|
*
|
|
* Copyright (C) 2020 Sungbo Eo <mans0n@gorani.run>
|
|
*
|
|
* Based on gpio-tpic2810.c
|
|
* Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
|
|
* Andrew F. Davis <afd@ti.com>
|
|
*/
|
|
|
|
#include <linux/gpio/driver.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/property.h>
|
|
|
|
/**
|
|
* struct pca9570 - GPIO driver data
|
|
* @chip: GPIO controller chip
|
|
* @lock: Protects write sequences
|
|
* @out: Buffer for device register
|
|
*/
|
|
struct pca9570 {
|
|
struct gpio_chip chip;
|
|
struct mutex lock;
|
|
u8 out;
|
|
};
|
|
|
|
static int pca9570_read(struct pca9570 *gpio, u8 *value)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(gpio->chip.parent);
|
|
int ret;
|
|
|
|
ret = i2c_smbus_read_byte(client);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
*value = ret;
|
|
return 0;
|
|
}
|
|
|
|
static int pca9570_write(struct pca9570 *gpio, u8 value)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(gpio->chip.parent);
|
|
|
|
return i2c_smbus_write_byte(client, value);
|
|
}
|
|
|
|
static int pca9570_get_direction(struct gpio_chip *chip,
|
|
unsigned offset)
|
|
{
|
|
/* This device always output */
|
|
return GPIO_LINE_DIRECTION_OUT;
|
|
}
|
|
|
|
static int pca9570_get(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
struct pca9570 *gpio = gpiochip_get_data(chip);
|
|
u8 buffer;
|
|
int ret;
|
|
|
|
ret = pca9570_read(gpio, &buffer);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return !!(buffer & BIT(offset));
|
|
}
|
|
|
|
static void pca9570_set(struct gpio_chip *chip, unsigned offset, int value)
|
|
{
|
|
struct pca9570 *gpio = gpiochip_get_data(chip);
|
|
u8 buffer;
|
|
int ret;
|
|
|
|
mutex_lock(&gpio->lock);
|
|
|
|
buffer = gpio->out;
|
|
if (value)
|
|
buffer |= BIT(offset);
|
|
else
|
|
buffer &= ~BIT(offset);
|
|
|
|
ret = pca9570_write(gpio, buffer);
|
|
if (ret)
|
|
goto out;
|
|
|
|
gpio->out = buffer;
|
|
|
|
out:
|
|
mutex_unlock(&gpio->lock);
|
|
}
|
|
|
|
static int pca9570_probe(struct i2c_client *client)
|
|
{
|
|
struct pca9570 *gpio;
|
|
|
|
gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
|
|
if (!gpio)
|
|
return -ENOMEM;
|
|
|
|
gpio->chip.label = client->name;
|
|
gpio->chip.parent = &client->dev;
|
|
gpio->chip.owner = THIS_MODULE;
|
|
gpio->chip.get_direction = pca9570_get_direction;
|
|
gpio->chip.get = pca9570_get;
|
|
gpio->chip.set = pca9570_set;
|
|
gpio->chip.base = -1;
|
|
gpio->chip.ngpio = (uintptr_t)device_get_match_data(&client->dev);
|
|
gpio->chip.can_sleep = true;
|
|
|
|
mutex_init(&gpio->lock);
|
|
|
|
/* Read the current output level */
|
|
pca9570_read(gpio, &gpio->out);
|
|
|
|
i2c_set_clientdata(client, gpio);
|
|
|
|
return devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio);
|
|
}
|
|
|
|
static const struct i2c_device_id pca9570_id_table[] = {
|
|
{ "pca9570", 4 },
|
|
{ "pca9571", 8 },
|
|
{ /* sentinel */ }
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, pca9570_id_table);
|
|
|
|
static const struct of_device_id pca9570_of_match_table[] = {
|
|
{ .compatible = "nxp,pca9570", .data = (void *)4 },
|
|
{ .compatible = "nxp,pca9571", .data = (void *)8 },
|
|
{ /* sentinel */ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, pca9570_of_match_table);
|
|
|
|
static struct i2c_driver pca9570_driver = {
|
|
.driver = {
|
|
.name = "pca9570",
|
|
.of_match_table = pca9570_of_match_table,
|
|
},
|
|
.probe_new = pca9570_probe,
|
|
.id_table = pca9570_id_table,
|
|
};
|
|
module_i2c_driver(pca9570_driver);
|
|
|
|
MODULE_AUTHOR("Sungbo Eo <mans0n@gorani.run>");
|
|
MODULE_DESCRIPTION("GPIO expander driver for PCA9570");
|
|
MODULE_LICENSE("GPL v2");
|