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![Rob Herring](/assets/img/avatar_default.png)
The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Acked-by: Romain Perier <romain.perier@gmail.com> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
195 lines
4.8 KiB
C
195 lines
4.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Digital I/O driver for Technologic Systems I2C FPGA Core
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*
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* Copyright (C) 2015, 2018 Technologic Systems
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* Copyright (C) 2016 Savoir-Faire Linux
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*/
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#include <linux/gpio/driver.h>
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#include <linux/i2c.h>
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#include <linux/of.h>
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#include <linux/module.h>
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#include <linux/regmap.h>
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#define DEFAULT_PIN_NUMBER 32
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/*
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* Register bits used by the GPIO device
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* Some boards, such as TS-7970 do not have a separate input bit
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*/
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#define TS4900_GPIO_OE 0x01
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#define TS4900_GPIO_OUT 0x02
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#define TS4900_GPIO_IN 0x04
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#define TS7970_GPIO_IN 0x02
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struct ts4900_gpio_priv {
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struct regmap *regmap;
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struct gpio_chip gpio_chip;
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unsigned int input_bit;
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};
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static int ts4900_gpio_get_direction(struct gpio_chip *chip,
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unsigned int offset)
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{
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struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
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unsigned int reg;
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regmap_read(priv->regmap, offset, ®);
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if (reg & TS4900_GPIO_OE)
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return GPIO_LINE_DIRECTION_OUT;
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return GPIO_LINE_DIRECTION_IN;
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}
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static int ts4900_gpio_direction_input(struct gpio_chip *chip,
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unsigned int offset)
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{
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struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
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/*
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* Only clear the OE bit here, requires a RMW. Prevents a potential issue
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* with OE and DAT getting to the physical pin at different times.
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*/
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return regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OE, 0);
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}
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static int ts4900_gpio_direction_output(struct gpio_chip *chip,
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unsigned int offset, int value)
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{
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struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
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unsigned int reg;
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int ret;
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/*
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* If changing from an input to an output, we need to first set the
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* GPIO's DAT bit to what is requested and then set the OE bit. This
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* prevents a glitch that can occur on the IO line.
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*/
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regmap_read(priv->regmap, offset, ®);
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if (!(reg & TS4900_GPIO_OE)) {
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if (value)
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reg = TS4900_GPIO_OUT;
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else
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reg &= ~TS4900_GPIO_OUT;
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regmap_write(priv->regmap, offset, reg);
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}
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if (value)
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ret = regmap_write(priv->regmap, offset, TS4900_GPIO_OE |
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TS4900_GPIO_OUT);
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else
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ret = regmap_write(priv->regmap, offset, TS4900_GPIO_OE);
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return ret;
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}
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static int ts4900_gpio_get(struct gpio_chip *chip, unsigned int offset)
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{
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struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
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unsigned int reg;
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regmap_read(priv->regmap, offset, ®);
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return !!(reg & priv->input_bit);
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}
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static void ts4900_gpio_set(struct gpio_chip *chip, unsigned int offset,
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int value)
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{
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struct ts4900_gpio_priv *priv = gpiochip_get_data(chip);
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if (value)
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regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OUT,
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TS4900_GPIO_OUT);
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else
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regmap_update_bits(priv->regmap, offset, TS4900_GPIO_OUT, 0);
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}
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static const struct regmap_config ts4900_regmap_config = {
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.reg_bits = 16,
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.val_bits = 8,
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};
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static const struct gpio_chip template_chip = {
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.label = "ts4900-gpio",
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.owner = THIS_MODULE,
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.get_direction = ts4900_gpio_get_direction,
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.direction_input = ts4900_gpio_direction_input,
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.direction_output = ts4900_gpio_direction_output,
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.get = ts4900_gpio_get,
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.set = ts4900_gpio_set,
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.base = -1,
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.can_sleep = true,
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};
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static const struct of_device_id ts4900_gpio_of_match_table[] = {
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{
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.compatible = "technologic,ts4900-gpio",
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.data = (void *)TS4900_GPIO_IN,
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}, {
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.compatible = "technologic,ts7970-gpio",
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.data = (void *)TS7970_GPIO_IN,
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},
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{ /* sentinel */ },
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};
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MODULE_DEVICE_TABLE(of, ts4900_gpio_of_match_table);
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static int ts4900_gpio_probe(struct i2c_client *client)
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{
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struct ts4900_gpio_priv *priv;
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u32 ngpio;
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int ret;
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if (of_property_read_u32(client->dev.of_node, "ngpios", &ngpio))
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ngpio = DEFAULT_PIN_NUMBER;
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priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->gpio_chip = template_chip;
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priv->gpio_chip.label = "ts4900-gpio";
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priv->gpio_chip.ngpio = ngpio;
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priv->gpio_chip.parent = &client->dev;
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priv->input_bit = (uintptr_t)of_device_get_match_data(&client->dev);
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priv->regmap = devm_regmap_init_i2c(client, &ts4900_regmap_config);
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if (IS_ERR(priv->regmap)) {
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ret = PTR_ERR(priv->regmap);
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dev_err(&client->dev, "Failed to allocate register map: %d\n",
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ret);
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return ret;
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}
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ret = devm_gpiochip_add_data(&client->dev, &priv->gpio_chip, priv);
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if (ret < 0) {
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dev_err(&client->dev, "Unable to register gpiochip\n");
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return ret;
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}
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i2c_set_clientdata(client, priv);
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return 0;
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}
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static const struct i2c_device_id ts4900_gpio_id_table[] = {
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{ "ts4900-gpio", },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(i2c, ts4900_gpio_id_table);
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static struct i2c_driver ts4900_gpio_driver = {
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.driver = {
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.name = "ts4900-gpio",
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.of_match_table = ts4900_gpio_of_match_table,
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},
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.probe = ts4900_gpio_probe,
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.id_table = ts4900_gpio_id_table,
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};
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module_i2c_driver(ts4900_gpio_driver);
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MODULE_AUTHOR("Technologic Systems");
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MODULE_DESCRIPTION("GPIO interface for Technologic Systems I2C-FPGA core");
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MODULE_LICENSE("GPL");
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