Re: [PATCH v3 08/13] mmc: mmci: add 8bit bus support in variant data

[Ulf Hansson <ulf.hansson@linaro.org>]

On 23 May 2014 14:52,  <srinivas.kandagatla@linaro.org> wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>
> This patch adds 8bit bus enable to variant structure giving more flexibility
> to the driver to support more SOCs which have different clock register layout.
>
> Without this patch other new SOCs like Qcom will have to add more code
> to special case them.
>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  drivers/mmc/host/mmci.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index dec70d2..a81f303 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -52,6 +52,7 @@ static unsigned int fmax = 515633;
>   * struct variant_data - MMCI variant-specific quirks
>   * @clkreg: default value for MCICLOCK register
>   * @clkreg_enable: enable value for MMCICLOCK register
> + * @clkreg_8bit_bus_enable: enable value for 8 bit bus
>   * @datalength_bits: number of bits in the MMCIDATALENGTH register
>   * @fifosize: number of bytes that can be written when MMCI_TXFIFOEMPTY
>   *           is asserted (likewise for RX)
> @@ -74,6 +75,7 @@ static unsigned int fmax = 515633;
>  struct variant_data {
>         unsigned int            clkreg;
>         unsigned int            clkreg_enable;
> +       unsigned int            clkreg_8bit_bus_enable;
>         unsigned int            datalength_bits;
>         unsigned int            fifosize;
>         unsigned int            fifohalfsize;
> @@ -116,6 +118,7 @@ static struct variant_data variant_u300 = {
>         .fifosize               = 16 * 4,
>         .fifohalfsize           = 8 * 4,
>         .clkreg_enable          = MCI_ST_U300_HWFCEN,
> +       .clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,

Linus, will have to confirm this. I don't know if the u300 variant
support 8-bit.

Kind regards
Ulf Hansson

>         .datactrl_mask_ddrmode  = MCI_ST_DPSM_DDRMODE,
>         .datalength_bits        = 16,
>         .sdio                   = true,
> @@ -144,6 +147,7 @@ static struct variant_data variant_ux500 = {
>         .fifohalfsize           = 8 * 4,
>         .clkreg                 = MCI_CLK_ENABLE,
>         .clkreg_enable          = MCI_ST_UX500_HWFCEN,
> +       .clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
>         .datactrl_mask_ddrmode  = MCI_ST_DPSM_DDRMODE,
>         .datalength_bits        = 24,
>         .sdio                   = true,
> @@ -160,6 +164,7 @@ static struct variant_data variant_ux500v2 = {
>         .fifohalfsize           = 8 * 4,
>         .clkreg                 = MCI_CLK_ENABLE,
>         .clkreg_enable          = MCI_ST_UX500_HWFCEN,
> +       .clkreg_8bit_bus_enable = MCI_ST_8BIT_BUS,
>         .datactrl_mask_ddrmode  = MCI_ST_DPSM_DDRMODE,
>         .datalength_bits        = 24,
>         .sdio                   = true,
> @@ -340,7 +345,7 @@ static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
>         if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
>                 clk |= MCI_4BIT_BUS;
>         if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
> -               clk |= MCI_ST_8BIT_BUS;
> +               clk |= variant->clkreg_8bit_bus_enable;
>
>         if (host->mmc->ios.timing == MMC_TIMING_UHS_DDR50)
>                 clk |= MCI_ST_UX500_NEG_EDGE;
> --
> 1.9.1
>