[U-Boot] [PATCH] xilinx_spi: Move timeout calculation out of the loop
Michal Simek
michal.simek at xilinx.com
Wed Jan 22 09:48:55 CET 2014
Timeout calculation should be out of the data loop.
This patch increase spi bandwidth for 30%.
Signed-off-by: Michal Simek <michal.simek at xilinx.com>
---
drivers/spi/xilinx_spi.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/spi/xilinx_spi.c b/drivers/spi/xilinx_spi.c
index 5ac0184..56d99d1 100644
--- a/drivers/spi/xilinx_spi.c
+++ b/drivers/spi/xilinx_spi.c
@@ -149,6 +149,7 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
const unsigned char *txp = dout;
unsigned char *rxp = din;
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__,
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)
spi_cs_activate(slave);
- while (bytes--) {
- unsigned timeout = /* at least 1usec or greater, leftover 1 */
- xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
+ /* at least 1usec or greater, leftover 1 */
+ global_timeout = xilspi->freq > XILSPI_MAX_XFER_BITS * 1000000 ? 2 :
(XILSPI_MAX_XFER_BITS * 1000000 / xilspi->freq) + 1;
+ while (bytes--) {
+ unsigned timeout = global_timeout;
/* get Tx element from data out buffer and count up */
unsigned char d = txp ? *txp++ : CONFIG_XILINX_SPI_IDLE_VAL;
debug("%s: tx:%x ", __func__, d);
--
1.8.2.3
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