diff options
| author | Lars-Peter Clausen <lars@metafoo.de> | 2013-11-25 12:42:00 +0000 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2013-12-03 20:22:27 +0000 |
| commit | 93dbad639d93300977ed76acc0db20771cca98f7 (patch) | |
| tree | fb2fa3c449799c093a6d8360c480961390fed7f1 /drivers/staging/iio | |
| parent | b39c47d1930191120d290e664740ba7ae04d0134 (diff) | |
staging:iio:ad7280a: Do not store transfer buffer on the stack
Some I2C controllers may not be able to handle transfer buffers that are placed
on the stack.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/staging/iio')
| -rw-r--r-- | drivers/staging/iio/adc/ad7280a.c | 29 |
1 files changed, 15 insertions, 14 deletions
diff --git a/drivers/staging/iio/adc/ad7280a.c b/drivers/staging/iio/adc/ad7280a.c index 89ee65bdc27..1ac11f64827 100644 --- a/drivers/staging/iio/adc/ad7280a.c +++ b/drivers/staging/iio/adc/ad7280a.c @@ -134,6 +134,8 @@ struct ad7280_state { unsigned char aux_threshhigh; unsigned char aux_threshlow; unsigned char cb_mask[AD7280A_MAX_CHAIN]; + + __be32 buf[2] ____cacheline_aligned; }; static void ad7280_crc8_build_table(unsigned char *crc_tab) @@ -189,22 +191,22 @@ static void ad7280_delay(struct ad7280_state *st) msleep(1); } -static int __ad7280_read32(struct spi_device *spi, unsigned *val) +static int __ad7280_read32(struct ad7280_state *st, unsigned *val) { - __be32 rx_buf, tx_buf = cpu_to_be32(AD7280A_READ_TXVAL); int ret; - struct spi_transfer t = { - .tx_buf = &tx_buf, - .rx_buf = &rx_buf, + .tx_buf = &st->buf[0], + .rx_buf = &st->buf[1], .len = 4, }; - ret = spi_sync_transfer(spi, &t, 1); + st->buf[0] = cpu_to_be32(AD7280A_READ_TXVAL); + + ret = spi_sync_transfer(st->spi, &t, 1); if (ret) return ret; - *val = be32_to_cpu(rx_buf); + *val = be32_to_cpu(st->buf[1]); return 0; } @@ -214,12 +216,11 @@ static int ad7280_write(struct ad7280_state *st, unsigned devaddr, { unsigned reg = (devaddr << 27 | addr << 21 | (val & 0xFF) << 13 | all << 12); - __be32 tx_buf; reg |= ad7280_calc_crc8(st->crc_tab, reg >> 11) << 3 | 0x2; - tx_buf = cpu_to_be32(reg); + st->buf[0] = cpu_to_be32(reg); - return spi_write(st->spi, &tx_buf, 4); + return spi_write(st->spi, &st->buf[0], 4); } static int ad7280_read(struct ad7280_state *st, unsigned devaddr, @@ -249,7 +250,7 @@ static int ad7280_read(struct ad7280_state *st, unsigned devaddr, if (ret) return ret; - __ad7280_read32(st->spi, &tmp); + __ad7280_read32(st, &tmp); if (ad7280_check_crc(st, tmp)) return -EIO; @@ -287,7 +288,7 @@ static int ad7280_read_channel(struct ad7280_state *st, unsigned devaddr, ad7280_delay(st); - __ad7280_read32(st->spi, &tmp); + __ad7280_read32(st, &tmp); if (ad7280_check_crc(st, tmp)) return -EIO; @@ -320,7 +321,7 @@ static int ad7280_read_all_channels(struct ad7280_state *st, unsigned cnt, ad7280_delay(st); for (i = 0; i < cnt; i++) { - __ad7280_read32(st->spi, &tmp); + __ad7280_read32(st, &tmp); if (ad7280_check_crc(st, tmp)) return -EIO; @@ -363,7 +364,7 @@ static int ad7280_chain_setup(struct ad7280_state *st) return ret; for (n = 0; n <= AD7280A_MAX_CHAIN; n++) { - __ad7280_read32(st->spi, &val); + __ad7280_read32(st, &val); if (val == 0) return n - 1; |