u8 tx_threshold;
u8 rx_threshold;
u8 dma_burst_size;
- u32 timeout_microsecs;
+ u32 timeout;
u8 enable_loopback;
void (*cs_control)(u32 command);
};
to determine the correct value. An SSP configured for byte-wide transfers would
use a value of 8.
-The "pxa2xx_spi_chip.timeout_microsecs" fields is used to efficiently handle
+The "pxa2xx_spi_chip.timeout" fields is used to efficiently handle
trailing bytes in the SSP receiver fifo. The correct value for this field is
dependent on the SPI bus speed ("spi_board_info.max_speed_hz") and the specific
-slave device. Please note the the PXA2xx SSP 1 does not support trailing byte
+slave device. Please note that the PXA2xx SSP 1 does not support trailing byte
timeouts and must busy-wait any trailing bytes.
The "pxa2xx_spi_chip.enable_loopback" field is used to place the SSP porting
into internal loopback mode. In this mode the SSP controller internally
-connects the SSPTX pin the the SSPRX pin. This is useful for initial setup
+connects the SSPTX pin to the SSPRX pin. This is useful for initial setup
testing.
The "pxa2xx_spi_chip.cs_control" field is used to point to a board specific
}
static struct pxa2xx_spi_chip cs8415a_chip_info = {
- .tx_threshold = 12, /* SSP hardward FIFO threshold */
- .rx_threshold = 4, /* SSP hardward FIFO threshold */
+ .tx_threshold = 8, /* SSP hardward FIFO threshold */
+ .rx_threshold = 8, /* SSP hardward FIFO threshold */
.dma_burst_size = 8, /* Byte wide transfers used so 8 byte bursts */
- .timeout_microsecs = 64, /* Wait at least 64usec to handle trailing */
+ .timeout = 235, /* See Intel documentation */
.cs_control = cs8415a_cs_control, /* Use external chip select */
};
static struct pxa2xx_spi_chip cs8405a_chip_info = {
- .tx_threshold = 12, /* SSP hardward FIFO threshold */
- .rx_threshold = 4, /* SSP hardward FIFO threshold */
+ .tx_threshold = 8, /* SSP hardward FIFO threshold */
+ .rx_threshold = 8, /* SSP hardward FIFO threshold */
.dma_burst_size = 8, /* Byte wide transfers used so 8 byte bursts */
- .timeout_microsecs = 64, /* Wait at least 64usec to handle trailing */
+ .timeout = 235, /* See Intel documentation */
.cs_control = cs8405a_cs_control, /* Use external chip select */
};
-----------------------
The pxa2xx_spi driver support both DMA and interrupt driven PIO message
transfers. The driver defaults to PIO mode and DMA transfers must enabled by
-setting the "enable_dma" flag in the "pxa2xx_spi_master" structure and and
+setting the "enable_dma" flag in the "pxa2xx_spi_master" structure and
ensuring that the "pxa2xx_spi_chip.dma_burst_size" field is non-zero. The DMA
mode support both coherent and stream based DMA mappings.