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>
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index cdf6681..ccd7840 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -74,7 +74,7 @@
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 @@
#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 @@
* @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 @@
* 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 @@
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 @@
/* 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