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clt.c
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clt.c
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#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/spi/spi.h>
struct clt_device {
struct spi_device *spi;
struct gpio_chip gpio_chip;
};
static int clt_read(struct spi_device *spi, u8 *val)
{
u8 buf[2];
struct spi_transfer xfer = {
.rx_buf = buf,
.len = 2,
};
int ret;
ret = spi_sync_transfer(spi, &xfer, 1);
if (ret < 0)
return ret;
*val = buf[0];
return 0;
}
static int clt_get_direction(struct gpio_chip *chip, unsigned int offset)
{
return GPIOF_DIR_IN;
}
static int clt_get(struct gpio_chip *chip, unsigned int offset)
{
struct clt_device *data = container_of(chip, struct clt_device, gpio_chip);
u8 val;
int ret;
ret = clt_read(data->spi, &val);
if (ret < 0)
return ret;
val >>= offset;
return val & 0x1;
}
static int clt_probe(struct spi_device *spi)
{
struct clt_device *data;
int ret;
spi->bits_per_word = 8;
ret = spi_setup(spi);
if (ret)
return ret;
data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->spi = spi;
data->gpio_chip.parent = &spi->dev;
data->gpio_chip.of_node = spi->dev.of_node;
data->gpio_chip.of_gpio_n_cells = 2;
data->gpio_chip.of_xlate = of_gpio_simple_xlate;
data->gpio_chip.base = -1;
data->gpio_chip.ngpio = 8;
data->gpio_chip.get_direction = clt_get_direction;
data->gpio_chip.get = clt_get;
ret = devm_gpiochip_add_data(&spi->dev, &data->gpio_chip, NULL);
if (ret) {
dev_err(&spi->dev, "Adding GPIO chip failed\n");
return ret;
}
spi_set_drvdata(spi, data);
dev_info(&spi->dev, "CLT01-38SQ7 probed\n");
return 0;
}
static int clt_remove(struct spi_device *spi)
{
//struct clt_device *data = spi_get_drvdata(spi);
//devm_gpiochip_remove(&data->gpio_chip);
return 0;
}
static const struct of_device_id clt_dt_ids[] = {
{ .compatible = "st,clt01-38sq7" },
{}
};
MODULE_DEVICE_TABLE(of, clt_dt_ids);
static struct spi_driver clt_spi_driver = {
.driver = {
.name = "clt01-38sq7",
.of_match_table = clt_dt_ids,
},
.probe = clt_probe,
.remove = clt_remove,
};
module_spi_driver(clt_spi_driver);
MODULE_LICENSE("GPL");