diff options
author | wangyuhang <wangyuhang2014@gmail.com> | 2013-08-11 18:15:17 +0800 |
---|---|---|
committer | Mark Brown <broonie@linaro.org> | 2013-08-22 13:47:29 +0100 |
commit | f477b7fb13df2b843997559ff34e87d054ba6538 (patch) | |
tree | 137825623bdd941ebd91a22f985c0352ee83a211 /include/linux/spi | |
parent | 56ede94a000bb9635b326db38baf66da6dfc174e (diff) | |
download | linux-stable-f477b7fb13df2b843997559ff34e87d054ba6538.tar.gz linux-stable-f477b7fb13df2b843997559ff34e87d054ba6538.tar.bz2 linux-stable-f477b7fb13df2b843997559ff34e87d054ba6538.zip |
spi: DUAL and QUAD support
fix the previous patch some mistake below:
1. DT in slave node, use "spi-tx-nbits = <1/2/4>" in place of using
"spi-tx-dual, spi-tx-quad" directly, same to rx. So correct the
previous way to get the property in @of_register_spi_devices().
2. Change the value of transfer bit macro(SPI_NBITS_SINGLE, SPI_NBITS_DUAL
SPI_NBITS_QUAD) to 0x01, 0x02 and 0x04 to match the actual wires.
3. Add the following check
(1)keep the tx_nbits and rx_nbits in spi_transfer is not beyond the
single, dual and quad.
(2)keep tx_nbits and rx_nbits are contained by @spi_device->mode
example: if @spi_device->mode = DUAL, then tx/rx_nbits can not be set
to QUAD(SPI_NBITS_QUAD)
(3)if "@spi_device->mode & SPI_3WIRE", then tx/rx_nbits should be in
single(SPI_NBITS_SINGLE)
Signed-off-by: wangyuhang <wangyuhang2014@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'include/linux/spi')
-rw-r--r-- | include/linux/spi/spi.h | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index cdf668156154..ccd7840c4507 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -74,7 +74,7 @@ struct spi_device { struct spi_master *master; u32 max_speed_hz; u8 chip_select; - u8 mode; + u16 mode; #define SPI_CPHA 0x01 /* clock phase */ #define SPI_CPOL 0x02 /* clock polarity */ #define SPI_MODE_0 (0|0) /* (original MicroWire) */ @@ -87,6 +87,10 @@ struct spi_device { #define SPI_LOOP 0x20 /* loopback mode */ #define SPI_NO_CS 0x40 /* 1 dev/bus, no chipselect */ #define SPI_READY 0x80 /* slave pulls low to pause */ +#define SPI_TX_DUAL 0x100 /* transmit with 2 wires */ +#define SPI_TX_QUAD 0x200 /* transmit with 4 wires */ +#define SPI_RX_DUAL 0x400 /* receive with 2 wires */ +#define SPI_RX_QUAD 0x800 /* receive with 4 wires */ u8 bits_per_word; int irq; void *controller_state; @@ -454,6 +458,10 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum); * @rx_buf: data to be read (dma-safe memory), or NULL * @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped * @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped + * @tx_nbits: number of bits used for writting. If 0 the default + * (SPI_NBITS_SINGLE) is used. + * @rx_nbits: number of bits used for reading. If 0 the default + * (SPI_NBITS_SINGLE) is used. * @len: size of rx and tx buffers (in bytes) * @speed_hz: Select a speed other than the device default for this * transfer. If 0 the default (from @spi_device) is used. @@ -508,6 +516,11 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum); * by the results of previous messages and where the whole transaction * ends when the chipselect goes intactive. * + * When SPI can transfer in 1x,2x or 4x. It can get this tranfer information + * from device through @tx_nbits and @rx_nbits. In Bi-direction, these + * two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x) + * SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer. + * * The code that submits an spi_message (and its spi_transfers) * to the lower layers is responsible for managing its memory. * Zero-initialize every field you don't set up explicitly, to @@ -528,6 +541,11 @@ struct spi_transfer { dma_addr_t rx_dma; unsigned cs_change:1; + u8 tx_nbits; + u8 rx_nbits; +#define SPI_NBITS_SINGLE 0x01 /* 1bit transfer */ +#define SPI_NBITS_DUAL 0x02 /* 2bits transfer */ +#define SPI_NBITS_QUAD 0x04 /* 4bits transfer */ u8 bits_per_word; u16 delay_usecs; u32 speed_hz; @@ -875,7 +893,7 @@ struct spi_board_info { /* mode becomes spi_device.mode, and is essential for chips * where the default of SPI_CS_HIGH = 0 is wrong. */ - u8 mode; + u16 mode; /* ... may need additional spi_device chip config data here. * avoid stuff protocol drivers can set; but include stuff |