[U-Boot] [PATCH v2 2/2] spi: mxs: Allow other chip selects to work

[Marek Vasut <marex@denx.de>]

Dear Fabio Estevam,

> MXS SSP controller may have up to three chip selects per port: SS0, SS1 and
> SS2.
> 
> Currently only SS0 is supported in the mxs_spi driver.
> 
> Allow all the three chip select to work by selecting the desired one
> in bits 20 and 21 of the HW_SSP_CTRL0 register.
> 
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

Acked-by: Marek Vasut <marex@denx.de>
> ---
> Changes since v1:
> - Check vor valid cs inside spi_cs_is_valid() (patch 1/2)
> 
>  drivers/spi/mxs_spi.c |   10 ++++++++++
>  1 files changed, 10 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
> index e7237e7..7859536 100644
> --- a/drivers/spi/mxs_spi.c
> +++ b/drivers/spi/mxs_spi.c
> @@ -34,6 +34,8 @@
> 
>  #define	MXS_SPI_MAX_TIMEOUT	1000000
>  #define	MXS_SPI_PORT_OFFSET	0x2000
> +#define MXS_SSP_CHIPSELECT_MASK		0x00300000
> +#define MXS_SSP_CHIPSELECT_SHIFT	20
> 
>  struct mxs_spi_slave {
>  	struct spi_slave	slave;
> @@ -65,6 +67,8 @@ struct spi_slave *spi_setup_slave(unsigned int bus,
> unsigned int cs, {
>  	struct mxs_spi_slave *mxs_slave;
>  	uint32_t addr;
> +	struct mx28_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);
> @@ -82,7 +86,13 @@ 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 = (struct mx28_ssp_regs *)addr;
> +	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;
>  }

Best regards,
Marek Vasut