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spi: xilinx: Move timeout calculation out of the loop 

Timeout calculation should be out of the data loop.
This patch increase spi bandwidth for 30%.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
This commit is contained in:
Michal Simek 2014-01-22 09:48:55 +01:00 committed by Jagannadha Sutradharudu Teki
parent 22a240c32c
commit 999c39a45f
1 changed files with 5 additions and 3 deletions
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8
drivers/spi/xilinx_spi.c
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@ -149,6 +149,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
const unsigned char *txp = dout; const unsigned char *txp = dout;
unsigned char *rxp = din; unsigned char *rxp = din;
unsigned rxecount = 17; /* max. 16 elements in FIFO, leftover 1 */ unsigned rxecount = 17; /* max. 16 elements in FIFO, leftover 1 */
unsigned global_timeout;
debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__, debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
slave->bus, slave->cs, bitlen, bytes, flags); slave->bus, slave->cs, bitlen, bytes, flags);
@ -176,11 +177,12 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
if (flags & SPI_XFER_BEGIN) if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave); spi_cs_activate(slave);
while (bytes--) { /* at least 1usec or greater, leftover 1 */
unsigned timeout = /* at least 1usec or greater, leftover 1 */ global_timeout = xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
(XILSPI_MAX_XFER_BITS * 1000000 / xilspi->freq) + 1; (XILSPI_MAX_XFER_BITS * 1000000 / xilspi->freq) + 1;
while (bytes--) {
unsigned timeout = global_timeout;
/* get Tx element from data out buffer and count up */ /* get Tx element from data out buffer and count up */
unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL; unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL;
debug("%s: tx:%x ", __func__, d); debug("%s: tx:%x ", __func__, d);