diff options
| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2018-12-07 13:07:55 +0000 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2018-12-21 09:23:45 +0100 |
| commit | abf221d2f51b8ce7b9959a8953f880a8b0a1400d (patch) | |
| tree | a894dff1b03d8d9a526a0f57a378a60fab1b0984 /drivers/gpio/gpio-max7301.c | |
| parent | 00ded24c33c586eaaf32764898c56f4a7d8c6d5c (diff) | |
gpio: max7301: fix driver for use with CONFIG_VMAP_STACK
spi_read() and spi_write() require DMA-safe memory. When
CONFIG_VMAP_STACK is selected, those functions cannot be used
with buffers on stack.
This patch replaces calls to spi_read() and spi_write() by
spi_write_then_read() which doesn't require DMA-safe buffers.
Fixes: 0c36ec314735 ("gpio: gpio driver for max7301 SPI GPIO expander")
Cc: <stable@vger.kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpio-max7301.c')
| -rw-r--r-- | drivers/gpio/gpio-max7301.c | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/drivers/gpio/gpio-max7301.c b/drivers/gpio/gpio-max7301.c index 05813fbf3daf..647dfbbc4e1c 100644 --- a/drivers/gpio/gpio-max7301.c +++ b/drivers/gpio/gpio-max7301.c @@ -25,7 +25,7 @@ static int max7301_spi_write(struct device *dev, unsigned int reg, struct spi_device *spi = to_spi_device(dev); u16 word = ((reg & 0x7F) << 8) | (val & 0xFF); - return spi_write(spi, (const u8 *)&word, sizeof(word)); + return spi_write_then_read(spi, &word, sizeof(word), NULL, 0); } /* A read from the MAX7301 means two transfers; here, one message each */ @@ -37,14 +37,8 @@ static int max7301_spi_read(struct device *dev, unsigned int reg) struct spi_device *spi = to_spi_device(dev); word = 0x8000 | (reg << 8); - ret = spi_write(spi, (const u8 *)&word, sizeof(word)); - if (ret) - return ret; - /* - * This relies on the fact, that a transfer with NULL tx_buf shifts out - * zero bytes (=NOOP for MAX7301) - */ - ret = spi_read(spi, (u8 *)&word, sizeof(word)); + ret = spi_write_then_read(spi, &word, sizeof(word), &word, + sizeof(word)); if (ret) return ret; return word & 0xff; |