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Diffstat (limited to 'drivers/spi/spidev.c')
-rw-r--r--drivers/spi/spidev.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 5d869c4d3eb2..606e7a40a8da 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -58,15 +58,20 @@ static unsigned long minors[N_SPI_MINORS / BITS_PER_LONG];
58 58
59 59
60/* Bit masks for spi_device.mode management. Note that incorrect 60/* Bit masks for spi_device.mode management. Note that incorrect
61 * settings for CS_HIGH and 3WIRE can cause *lots* of trouble for other 61 * settings for some settings can cause *lots* of trouble for other
62 * devices on a shared bus: CS_HIGH, because this device will be 62 * devices on a shared bus:
63 * active when it shouldn't be; 3WIRE, because when active it won't
64 * behave as it should.
65 * 63 *
66 * REVISIT should changing those two modes be privileged? 64 * - CS_HIGH ... this device will be active when it shouldn't be
65 * - 3WIRE ... when active, it won't behave as it should
66 * - NO_CS ... there will be no explicit message boundaries; this
67 * is completely incompatible with the shared bus model
68 * - READY ... transfers may proceed when they shouldn't.
69 *
70 * REVISIT should changing those flags be privileged?
67 */ 71 */
68#define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \ 72#define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \
69 | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP) 73 | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \
74 | SPI_NO_CS | SPI_READY)
70 75
71struct spidev_data { 76struct spidev_data {
72 dev_t devt; 77 dev_t devt;