diff options
| author | Magnus Damm <damm@opensource.se> | 2009-11-26 11:10:05 +0000 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2009-12-13 00:48:27 -0700 |
| commit | 8051effcbced8478119167b93b0e9554cb82d28e (patch) | |
| tree | 03ce88851ca697c8ed5f1d8eadcb32972342dbac /include | |
| parent | 41df70d9ac2d0d36b23a0ec4866f67e540f366ff (diff) | |
spi: SuperH MSIOF SPI Master driver V2
This patch is V2 of SPI Master support for the SuperH MSIOF.
Full duplex, spi mode 0-3, active high cs, 3-wire and lsb
first should all be supported, but the driver has so far
only been tested with "mmc_spi".
The MSIOF hardware comes with 32-bit FIFOs for receive and
transmit, and this driver simply breaks the SPI messages
into FIFO-sized chunks. The MSIOF hardware manages the pins
for clock, receive and transmit (sck/miso/mosi), but the chip
select pin is managed by software and must be configured as
a regular GPIO pin by the board code.
Performance wise there is still room for improvement, but
on a Ecovec board with the built-in sh7724 MSIOF0 this driver
gets Mini-sd read speeds of about half a megabyte per second.
Future work include better clock setup and merging of 8-bit
transfers into 32-bit words to reduce interrupt load and
improve throughput.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/spi/sh_msiof.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/spi/sh_msiof.h b/include/linux/spi/sh_msiof.h new file mode 100644 index 00000000000..2e8db3d2d2e --- /dev/null +++ b/include/linux/spi/sh_msiof.h @@ -0,0 +1,10 @@ +#ifndef __SPI_SH_MSIOF_H__ +#define __SPI_SH_MSIOF_H__ + +struct sh_msiof_spi_info { + int tx_fifo_override; + int rx_fifo_override; + u16 num_chipselect; +}; + +#endif /* __SPI_SH_MSIOF_H__ */ |