diff options
| author | Tom Warren <twarren@nvidia.com> | 2012-05-15 14:32:40 -0700 |
|---|---|---|
| committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2012-07-07 14:07:17 +0200 |
| commit | 078078cfa91f72331421e6f7a46938a58a9b21a7 (patch) | |
| tree | 236b72582ed1f21e966b1d1fc89270cd36d9245d /drivers/spi | |
| parent | 558cd995d6d3eaa94fb342d142289a1fa2f76ba3 (diff) | |
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/spi')
| -rw-r--r-- | drivers/spi/tegra2_spi.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/spi/tegra2_spi.c b/drivers/spi/tegra2_spi.c index 56cb22963..fe7b405b1 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, |