diff options
Diffstat (limited to 'drivers/spi/spidev.c')
-rw-r--r-- | drivers/spi/spidev.c | 17 |
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 | ||
71 | struct spidev_data { | 76 | struct spidev_data { |
72 | dev_t devt; | 77 | dev_t devt; |