[U-Boot] [PATCH V2] spi: mxs: Configure chipselect after block reset
Stefano Babic
sbabic at denx.de
Mon Aug 26 18:04:35 CEST 2013
On 26/08/2013 17:45, Marek Vasut wrote:
> The chipselect must be written into the CTRL0 register after the SSP
> block is reset, otherwise the block will always use ChipSelect #0.
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Fabio Estevam <fabio.estevam at freescale.com>
> Cc: Jagannadha Sutradharudu Teki <jagannadh.teki at gmail.com>
> Cc: Otavio Salvador <otavio at ossystems.com.br>
> Cc: Stefano Babic <sbabic at denx.de>
> ---
> drivers/spi/mxs_spi.c | 12 +++---------
> 1 file changed, 3 insertions(+), 9 deletions(-)
>
> V2: Clean up a warning that "ssp_regs" are not used
>
> diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
> index 3cf7142..2b9f395 100644
> --- a/drivers/spi/mxs_spi.c
> +++ b/drivers/spi/mxs_spi.c
> @@ -56,8 +56,6 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
> unsigned int max_hz, unsigned int mode)
> {
> struct mxs_spi_slave *mxs_slave;
> - struct mxs_ssp_regs *ssp_regs;
> - int reg;
>
> if (!spi_cs_is_valid(bus, cs)) {
> printf("mxs_spi: invalid bus %d / chip select %d\n", bus, cs);
> @@ -74,13 +72,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
> mxs_slave->max_khz = max_hz / 1000;
> mxs_slave->mode = mode;
> mxs_slave->regs = mxs_ssp_regs_by_bus(bus);
> - ssp_regs = mxs_slave->regs;
>
> - reg = readl(&ssp_regs->hw_ssp_ctrl0);
> - reg &= ~(MXS_SSP_CHIPSELECT_MASK);
> - reg |= cs << MXS_SSP_CHIPSELECT_SHIFT;
> -
> - writel(reg, &ssp_regs->hw_ssp_ctrl0);
> return &mxs_slave->slave;
>
> err_init:
> @@ -102,7 +94,9 @@ int spi_claim_bus(struct spi_slave *slave)
>
> mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
>
> - writel(SSP_CTRL0_BUS_WIDTH_ONE_BIT, &ssp_regs->hw_ssp_ctrl0);
> + writel((slave->cs << MXS_SSP_CHIPSELECT_SHIFT) |
> + SSP_CTRL0_BUS_WIDTH_ONE_BIT,
> + &ssp_regs->hw_ssp_ctrl0);
>
> reg = SSP_CTRL1_SSP_MODE_SPI | SSP_CTRL1_WORD_LENGTH_EIGHT_BITS;
> reg |= (mxs_slave->mode & SPI_CPOL) ? SSP_CTRL1_POLARITY : 0;
>
Acked-by: Stefano Babic <sbabic at denx.de>
Best regards,
Stefano Babic
--
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