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authorTom Warren <twarren@nvidia.com>2012-05-15 14:32:40 -0700
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2012-07-07 14:07:17 +0200
commit078078cfa91f72331421e6f7a46938a58a9b21a7 (patch)
tree236b72582ed1f21e966b1d1fc89270cd36d9245d /drivers
parent558cd995d6d3eaa94fb342d142289a1fa2f76ba3 (diff)
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spi: Tegra2: Seaboard: fix UART corruption during SPI transactions
Simon Glass's proposal to fix this on Seaboard was NAK'd, so I removed his NS16550 references and added a small delay before SPI/UART muxing. Tested on my Seaboard with large SPI reads/writes and saw no corruption (crc's matched) and no spurious comm chars. Signed-off-by: Tom Warren <twarren@nvidia.com> Acked-by: Simon Glass <sjg@chromium.org> Tested-by: Jimmy Zhang <jimmzhang@nvidia.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/spi/tegra2_spi.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/spi/tegra2_spi.c b/drivers/spi/tegra2_spi.c
index 56cb229..fe7b405 100644
--- a/drivers/spi/tegra2_spi.c
+++ b/drivers/spi/tegra2_spi.c
@@ -28,13 +28,18 @@
#include <spi.h>
#include <asm/io.h>
#include <asm/gpio.h>
-#include <ns16550.h>
#include <asm/arch/clk_rst.h>
#include <asm/arch/clock.h>
#include <asm/arch/pinmux.h>
#include <asm/arch/uart-spi-switch.h>
#include <asm/arch/tegra2_spi.h>
+#if defined(CONFIG_SPI_CORRUPTS_UART)
+ #define corrupt_delay() udelay(CONFIG_SPI_CORRUPTS_UART_DLY);
+#else
+ #define corrupt_delay()
+#endif
+
struct tegra_spi_slave {
struct spi_slave slave;
struct spi_tegra *regs;
@@ -161,14 +166,20 @@ void spi_cs_activate(struct spi_slave *slave)
/* CS is negated on Tegra, so drive a 1 to get a 0 */
setbits_le32(&spi->regs->command, SPI_CMD_CS_VAL);
+
+ corrupt_delay(); /* Let UART settle */
}
void spi_cs_deactivate(struct spi_slave *slave)
{
struct tegra_spi_slave *spi = to_tegra_spi(slave);
+ pinmux_select_uart();
+
/* CS is negated on Tegra, so drive a 0 to get a 1 */
clrbits_le32(&spi->regs->command, SPI_CMD_CS_VAL);
+
+ corrupt_delay(); /* Let SPI settle */
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen,