Orange Pi5 kernel

// 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 },
<------>{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, pca9570_id_table);
 
static const struct of_device_id pca9570_of_match_table[] = {
<------>{ .compatible = "nxp,pca9570", .data = (void *)4 },
<------>{ /* 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");