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authorMagnus Damm <damm@opensource.se>2009-11-26 11:10:05 +0000
committerGrant Likely <grant.likely@secretlab.ca>2009-12-13 00:48:27 -0700
commit8051effcbced8478119167b93b0e9554cb82d28e (patch)
tree03ce88851ca697c8ed5f1d8eadcb32972342dbac /include/linux/spi
parent41df70d9ac2d0d36b23a0ec4866f67e540f366ff (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/linux/spi')
-rw-r--r--include/linux/spi/sh_msiof.h10
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 000000000000..2e8db3d2d2e5
--- /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__ */