Orange Pi5 kernel

/*
 * Digital I/O driver for Technologic Systems I2C FPGA Core
 *
 * Copyright (C) 2015, 2018 Technologic Systems
 * Copyright (C) 2016 Savoir-Faire Linux
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether expressed or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License version 2 for more details.
 */
 
#include <linux/gpio/driver.h>
#include <linux/i2c.h>
#include <linux/of_device.h>
#include <linux/module.h>
#include <linux/regmap.h>
 
#define DEFAULT_PIN_NUMBER	32
/*
 * Register bits used by the GPIO device
 * Some boards, such as TS-7970 do not have a separate input bit
 */
#define TS4900_GPIO_OE		0x01
#define TS4900_GPIO_OUT		0x02
#define TS4900_GPIO_IN		0x04
#define TS7970_GPIO_IN		0x02
 
struct ts4900_gpio_priv {
<------>struct regmap *regmap;
<------>struct gpio_chip gpio_chip;
<------>unsigned int input_bit;
};
 
static int ts4900_gpio_get_direction(struct gpio_chip *chip,
<------><------><------><------>     unsigned int offset)
{
<------>struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
<------>unsigned int reg;
 
<------>regmap_read(priv->regmap, offset, &reg);
 
<------>if (reg & TS4900_GPIO_OE)
<------><------>return GPIO_LINE_DIRECTION_OUT;
 
<------>return GPIO_LINE_DIRECTION_IN;
}
 
static int ts4900_gpio_direction_input(struct gpio_chip *chip,
<------><------><------><------>       unsigned int offset)
{
<------>struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
 
<------>/* Only clear the OE bit here, requires a RMW. Prevents potential issue
<------> * with OE and data getting to the physical pin at different times.
<------> */
<------>return regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OE, 0);
}
 
static int ts4900_gpio_direction_output(struct gpio_chip *chip,
<------><------><------><------><------>unsigned int offset, int value)
{
<------>struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
<------>unsigned int reg;
<------>int ret;
 
<------>/* If changing from an input to an output, we need to first set the
<------> * proper data bit to what is requested and then set OE bit. This
<------> * prevents a glitch that can occur on the IO line
<------> */
<------>regmap_read(priv->regmap, offset, &reg);
<------>if (!(reg & TS4900_GPIO_OE)) {
<------><------>if (value)
<------><------><------>reg = TS4900_GPIO_OUT;
<------><------>else
<------><------><------>reg &= ~TS4900_GPIO_OUT;
 
<------><------>regmap_write(priv->regmap, offset, reg);
<------>}
 
<------>if (value)
<------><------>ret = regmap_write(priv->regmap, offset, TS4900_GPIO_OE |
<------><------><------><------><------><------><------> TS4900_GPIO_OUT);
<------>else
<------><------>ret = regmap_write(priv->regmap, offset, TS4900_GPIO_OE);
 
<------>return ret;
}
 
static int ts4900_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
<------>struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
<------>unsigned int reg;
 
<------>regmap_read(priv->regmap, offset, &reg);
 
<------>return !!(reg & priv->input_bit);
}
 
static void ts4900_gpio_set(struct gpio_chip *chip, unsigned int offset,
<------><------><------>    int value)
{
<------>struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
 
<------>if (value)
<------><------>regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OUT,
<------><------><------><------>   TS4900_GPIO_OUT);
<------>else
<------><------>regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OUT, 0);
}
 
static const struct regmap_config ts4900_regmap_config = {
<------>.reg_bits = 16,
<------>.val_bits = 8,
};
 
static const struct gpio_chip template_chip = {
<------>.label			= "ts4900-gpio",
<------>.owner			= THIS_MODULE,
<------>.get_direction		= ts4900_gpio_get_direction,
<------>.direction_input	= ts4900_gpio_direction_input,
<------>.direction_output	= ts4900_gpio_direction_output,
<------>.get			= ts4900_gpio_get,
<------>.set			= ts4900_gpio_set,
<------>.base			= -1,
<------>.can_sleep		= true,
};
 
static const struct of_device_id ts4900_gpio_of_match_table[] = {
<------>{
<------><------>.compatible = "technologic,ts4900-gpio",
<------><------>.data = (void *)TS4900_GPIO_IN,
<------>}, {
<------><------>.compatible = "technologic,ts7970-gpio",
<------><------>.data = (void *)TS7970_GPIO_IN,
<------>},
<------>{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, ts4900_gpio_of_match_table);
 
static int ts4900_gpio_probe(struct i2c_client *client,
<------><------><------>const struct i2c_device_id *id)
{
<------>struct ts4900_gpio_priv *priv;
<------>u32 ngpio;
<------>int ret;
 
<------>if (of_property_read_u32(client->dev.of_node, "ngpios", &ngpio))
<------><------>ngpio = DEFAULT_PIN_NUMBER;
 
<------>priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
<------>if (!priv)
<------><------>return -ENOMEM;
 
<------>priv->gpio_chip = template_chip;
<------>priv->gpio_chip.label = "ts4900-gpio";
<------>priv->gpio_chip.ngpio = ngpio;
<------>priv->gpio_chip.parent = &client->dev;
<------>priv->input_bit = (uintptr_t)of_device_get_match_data(&client->dev);
 
<------>priv->regmap = devm_regmap_init_i2c(client, &ts4900_regmap_config);
<------>if (IS_ERR(priv->regmap)) {
<------><------>ret = PTR_ERR(priv->regmap);
<------><------>dev_err(&client->dev, "Failed to allocate register map: %d\n",
<------><------><------>ret);
<------><------>return ret;
<------>}
 
<------>ret = devm_gpiochip_add_data(&client->dev, &priv->gpio_chip, priv);
<------>if (ret < 0) {
<------><------>dev_err(&client->dev, "Unable to register gpiochip\n");
<------><------>return ret;
<------>}
 
<------>i2c_set_clientdata(client, priv);
 
<------>return 0;
}
 
static const struct i2c_device_id ts4900_gpio_id_table[] = {
<------>{ "ts4900-gpio", },
<------>{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, ts4900_gpio_id_table);
 
static struct i2c_driver ts4900_gpio_driver = {
<------>.driver = {
<------><------>.name = "ts4900-gpio",
<------><------>.of_match_table = ts4900_gpio_of_match_table,
<------>},
<------>.probe = ts4900_gpio_probe,
<------>.id_table = ts4900_gpio_id_table,
};
module_i2c_driver(ts4900_gpio_driver);
 
MODULE_AUTHOR("Technologic Systems");
MODULE_DESCRIPTION("GPIO interface for Technologic Systems I2C-FPGA core");
MODULE_LICENSE("GPL");