diff options
-rw-r--r-- | drivers/gpio/gpio-74x164.c | 47 |
1 files changed, 15 insertions, 32 deletions
diff --git a/drivers/gpio/gpio-74x164.c b/drivers/gpio/gpio-74x164.c index b0939e0ff0b9..54a4147fba52 100644 --- a/drivers/gpio/gpio-74x164.c +++ b/drivers/gpio/gpio-74x164.c @@ -23,6 +23,13 @@ struct gen_74x164_chip { struct gpio_chip gpio_chip; struct mutex lock; u32 registers; + /* + * 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 sent will end up in the last + * register at the end of the transfer. So, to have a logical + * numbering, store the bytes in reverse order. + */ u8 buffer[0]; }; @@ -33,43 +40,19 @@ static struct gen_74x164_chip *gpio_to_74x164_chip(struct gpio_chip *gc) static int __gen_74x164_write_config(struct gen_74x164_chip *chip) { - struct spi_device *spi = to_spi_device(chip->gpio_chip.parent); - 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); + struct spi_transfer xfer = { + .tx_buf = chip->buffer, + .len = chip->registers, + }; - /* - * 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 - * 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. - */ - 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); - - kfree(msg_buf); - - 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; + u8 bank = chip->registers - 1 - offset / 8; u8 pin = offset % 8; int ret; @@ -84,7 +67,7 @@ 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; + u8 bank = chip->registers - 1 - offset / 8; u8 pin = offset % 8; mutex_lock(&chip->lock); |