linux/drivers/gpio/gpio-ts4900.c
Linus Torvalds 26803bac2b gpio fixes for v5.18-rc1
- grammar and formatting fixes in comments for gpio-ts4900
 - correct links in gpio-ts5500
 - fix a warning in doc generation for the core GPIO documentation
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEFp3rbAvDxGAT0sefEacuoBRx13IFAmJHBBQACgkQEacuoBRx
 13Ih3A//bkylULu9FUjRS+zFlpbN+BFFNtDTfVKic0wRsJhU+eJb4pbpC6ZokyqT
 NxkIm8qvZHb3RUFB6qPm44UbuELjeU09E4atxUfuiBNyb0t8WAW0YgFAQql7RweX
 mwTQ82+ARQm1qGhsqxKwRn0qFlMEdBLvYVGffVZp3NbOGaAIIKpCu5ZvWg9yC6rW
 ksAE0jmmxY1ak2H0q5D0VPj1aScZhXjaN94GTCYbTRAY0SSZMxbkuG3Mo6vLO8go
 u3jsZ7hGaGvadNcpmtmA0sqWLXVq7qCi6CdmUM6iTnIsPMHwUi9I722VKQzE2yS/
 bp8v7YOUhEAT+324QzLxTDZjZWSJnFf9tJ24pjUl0V9M6+31iSnf3uNWijfCJgG5
 SHdJeZUx6vqqyN2JObHng5zdYS38TksywmkijrVas/C7IHl9sRZLJPM5Qg9bKuGO
 PwOr0zuOlTxhi3R91dvOECZsan159gnnpnZFinYrqsIrOOt9VRkdv97en+4nV2p0
 vgnwLRBDanMF7y7/8yyZzDGip+qI+3L3j/6x6WvFhPWaXqda3Xoh6rSj0JHM0BOi
 x1qvzI/wokOZN6aBrbJoFfDcbL6nU+QWLBxlB2/prMMVh7KD7yDyE3wvQVZGx/xt
 zPQJksXIFLebtVQ1TGfClgsqYoPfk/E3epouOfdaryXb1tPiD0A=
 =9+Rg
 -----END PGP SIGNATURE-----

Merge tag 'gpio-fixes-for-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux

Pull gpio fixes from Bartosz Golaszewski:

 - grammar and formatting fixes in comments for gpio-ts4900

 - correct links in gpio-ts5500

 - fix a warning in doc generation for the core GPIO documentation

* tag 'gpio-fixes-for-v5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: ts5500: Fix Links to Technologic Systems web resources
  gpio: Properly document parent data union
  gpio: ts4900: Fix comment formatting and grammar
2022-04-01 10:26:09 -07:00

197 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Digital I/O driver for Technologic Systems I2C FPGA Core
*
* Copyright (C) 2015, 2018 Technologic Systems
* Copyright (C) 2016 Savoir-Faire Linux
*/
#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 a potential issue
* with OE and DAT 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
* GPIO's DAT bit to what is requested and then set the 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");