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authorBarry Song <barry.song@analog.com>2010-04-06 03:36:24 +0000
committerMike Frysinger <vapier@gentoo.org>2010-10-18 02:49:43 -0400
commit4190f6a51f3f9c7c8298202d31b3ead9381c33f1 (patch)
treeb1afa6ba60935d2a8036714ea46d4acd8b36a877 /drivers
parente72dcde72c712708e2145ab0ecff539ff4a4c7fb (diff)
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spi/bfin_spi: warn when CS is driven by hardware (CPHA=0)
When the hardware is controlling the CS, there are some SPI options we are unable to support. So issue a warning in the hopes that the user will change to a SPI mode where we can support things sanely. Signed-off-by: Barry Song <barry.song@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/spi/spi_bfin5xx.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index 7882afcd580f..21de8605dbce 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -1040,9 +1040,14 @@ static int bfin_spi_setup(struct spi_device *spi)
*/
chip->baud = hz_to_spi_baud(spi->max_speed_hz);
chip->chip_select_num = spi->chip_select;
- if (chip->chip_select_num < MAX_CTRL_CS)
+ if (chip->chip_select_num < MAX_CTRL_CS) {
+ if (!(spi->mode & SPI_CPHA))
+ dev_warn(&spi->dev, "Warning: SPI CPHA not set:"
+ " Slave Select not under software control!\n"
+ " See Documentation/blackfin/bfin-spi-notes.txt");
+
chip->flag = (1 << spi->chip_select) << 8;
- else
+ } else
chip->cs_gpio = chip->chip_select_num - MAX_CTRL_CS;
if (chip->enable_dma && chip->pio_interrupt) {