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path: root/drivers/gpio/gpio-74x164.c
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Diffstat (limited to 'drivers/gpio/gpio-74x164.c')
-rw-r--r--drivers/gpio/gpio-74x164.c79
1 files changed, 28 insertions, 51 deletions
diff --git a/drivers/gpio/gpio-74x164.c b/drivers/gpio/gpio-74x164.c
index 60172f835..c81224ff2 100644
--- a/drivers/gpio/gpio-74x164.c
+++ b/drivers/gpio/gpio-74x164.c
@@ -20,56 +20,34 @@
#define GEN_74X164_NUMBER_GPIOS 8
struct gen_74x164_chip {
- u8 *buffer;
struct gpio_chip gpio_chip;
struct mutex lock;
u32 registers;
-};
-
-static struct gen_74x164_chip *gpio_to_74x164_chip(struct gpio_chip *gc)
-{
- return container_of(gc, struct gen_74x164_chip, gpio_chip);
-}
-
-static int __gen_74x164_write_config(struct gen_74x164_chip *chip)
-{
- struct spi_device *spi = to_spi_device(chip->gpio_chip.dev);
- struct spi_message message;
- struct spi_transfer *msg_buf;
- int i, ret = 0;
-
- msg_buf = kzalloc(chip->registers * sizeof(struct spi_transfer),
- GFP_KERNEL);
- if (!msg_buf)
- return -ENOMEM;
-
- spi_message_init(&message);
-
/*
* Since the registers are chained, every byte sent will make
* the previous byte shift to the next register in the
- * chain. Thus, the first byte send will end up in the last
+ * chain. Thus, the first byte sent will end up in the last
* register at the end of the transfer. So, to have a logical
- * numbering, send the bytes in reverse order so that the last
- * byte of the buffer will end up in the last register.
+ * numbering, store the bytes in reverse order.
*/
- for (i = chip->registers - 1; i >= 0; i--) {
- msg_buf[i].tx_buf = chip->buffer + i;
- msg_buf[i].len = sizeof(u8);
- spi_message_add_tail(msg_buf + i, &message);
- }
-
- ret = spi_sync(spi, &message);
+ u8 buffer[0];
+};
- kfree(msg_buf);
+static int __gen_74x164_write_config(struct gen_74x164_chip *chip)
+{
+ struct spi_transfer xfer = {
+ .tx_buf = chip->buffer,
+ .len = chip->registers,
+ };
- return ret;
+ return spi_sync_transfer(to_spi_device(chip->gpio_chip.parent),
+ &xfer, 1);
}
static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset)
{
- struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
- u8 bank = offset / 8;
+ struct gen_74x164_chip *chip = gpiochip_get_data(gc);
+ u8 bank = chip->registers - 1 - offset / 8;
u8 pin = offset % 8;
int ret;
@@ -83,8 +61,8 @@ static int gen_74x164_get_value(struct gpio_chip *gc, unsigned offset)
static void gen_74x164_set_value(struct gpio_chip *gc,
unsigned offset, int val)
{
- struct gen_74x164_chip *chip = gpio_to_74x164_chip(gc);
- u8 bank = offset / 8;
+ struct gen_74x164_chip *chip = gpiochip_get_data(gc);
+ u8 bank = chip->registers - 1 - offset / 8;
u8 pin = offset % 8;
mutex_lock(&chip->lock);
@@ -107,6 +85,7 @@ static int gen_74x164_direction_output(struct gpio_chip *gc,
static int gen_74x164_probe(struct spi_device *spi)
{
struct gen_74x164_chip *chip;
+ u32 nregs;
int ret;
/*
@@ -118,7 +97,14 @@ static int gen_74x164_probe(struct spi_device *spi)
if (ret < 0)
return ret;
- chip = devm_kzalloc(&spi->dev, sizeof(*chip), GFP_KERNEL);
+ if (of_property_read_u32(spi->dev.of_node, "registers-number",
+ &nregs)) {
+ dev_err(&spi->dev,
+ "Missing registers-number property in the DT.\n");
+ return -EINVAL;
+ }
+
+ chip = devm_kzalloc(&spi->dev, sizeof(*chip) + nregs, GFP_KERNEL);
if (!chip)
return -ENOMEM;
@@ -130,20 +116,11 @@ static int gen_74x164_probe(struct spi_device *spi)
chip->gpio_chip.set = gen_74x164_set_value;
chip->gpio_chip.base = -1;
- if (of_property_read_u32(spi->dev.of_node, "registers-number",
- &chip->registers)) {
- dev_err(&spi->dev,
- "Missing registers-number property in the DT.\n");
- return -EINVAL;
- }
-
+ chip->registers = nregs;
chip->gpio_chip.ngpio = GEN_74X164_NUMBER_GPIOS * chip->registers;
- chip->buffer = devm_kzalloc(&spi->dev, chip->registers, GFP_KERNEL);
- if (!chip->buffer)
- return -ENOMEM;
chip->gpio_chip.can_sleep = true;
- chip->gpio_chip.dev = &spi->dev;
+ chip->gpio_chip.parent = &spi->dev;
chip->gpio_chip.owner = THIS_MODULE;
mutex_init(&chip->lock);
@@ -154,7 +131,7 @@ static int gen_74x164_probe(struct spi_device *spi)
goto exit_destroy;
}
- ret = gpiochip_add(&chip->gpio_chip);
+ ret = gpiochip_add_data(&chip->gpio_chip, chip);
if (!ret)
return 0;