Re: [PATCH v4 11/13] mmc: mmci: add f_max to variant structure

[Ulf Hansson]

On 28 May 2014 15:47,  <srinivas.kandagatla@xxxxxxxxxx> wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
>
> Some of the controller have maximum supported frequency, This patch adds
> support in variant data structure to specify such restrictions. This
> gives more flexibility in calculating the f_max before passing it to
> mmc-core.
>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
>  drivers/mmc/host/mmci.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index fd40f9a..202f2d5 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -67,6 +67,7 @@ static unsigned int fmax = 515633;
>   * @blksz_datactrl4: true if Block size is at b4..b16 position in datactrl
>   *                  register
>   * @pwrreg_powerup: power up value for MMCIPOWER register
> + * @f_max: maximum clk frequency supported by the controller.
>   * @signal_direction: input/out direction of bus signals can be indicated
>   * @pwrreg_clkgate: MMCIPOWER register must be used to gate the clock
>   * @busy_detect: true if busy detection on dat0 is supported
> @@ -87,6 +88,7 @@ struct variant_data {
>         bool                    blksz_datactrl16;
>         bool                    blksz_datactrl4;
>         u32                     pwrreg_powerup;
> +       u32                     f_max;
>         bool                    signal_direction;
>         bool                    pwrreg_clkgate;
>         bool                    busy_detect;
> @@ -98,6 +100,7 @@ static struct variant_data variant_arm = {
>         .fifohalfsize           = 8 * 4,
>         .datalength_bits        = 16,
>         .pwrreg_powerup         = MCI_PWR_UP,
> +       .f_max                  = 100000000,
>  };
>
>  static struct variant_data variant_arm_extended_fifo = {
> @@ -105,6 +108,7 @@ static struct variant_data variant_arm_extended_fifo = {
>         .fifohalfsize           = 64 * 4,
>         .datalength_bits        = 16,
>         .pwrreg_powerup         = MCI_PWR_UP,
> +       .f_max                  = 100000000,
>  };
>
>  static struct variant_data variant_arm_extended_fifo_hwfc = {
> @@ -113,6 +117,7 @@ static struct variant_data variant_arm_extended_fifo_hwfc = {
>         .clkreg_enable          = MCI_ARM_HWFCEN,
>         .datalength_bits        = 16,
>         .pwrreg_powerup         = MCI_PWR_UP,
> +       .f_max                  = 100000000,
>  };
>
>  static struct variant_data variant_u300 = {
> @@ -123,6 +128,7 @@ static struct variant_data variant_u300 = {
>         .datalength_bits        = 16,
>         .sdio                   = true,
>         .pwrreg_powerup         = MCI_PWR_ON,
> +       .f_max                  = 100000000,
>         .signal_direction       = true,
>         .pwrreg_clkgate         = true,
>         .pwrreg_nopower         = true,
> @@ -136,6 +142,7 @@ static struct variant_data variant_nomadik = {
>         .sdio                   = true,
>         .st_clkdiv              = true,
>         .pwrreg_powerup         = MCI_PWR_ON,
> +       .f_max                  = 100000000,
>         .signal_direction       = true,
>         .pwrreg_clkgate         = true,
>         .pwrreg_nopower         = true,
> @@ -152,6 +159,7 @@ static struct variant_data variant_ux500 = {
>         .sdio                   = true,
>         .st_clkdiv              = true,
>         .pwrreg_powerup         = MCI_PWR_ON,
> +       .f_max                  = 100000000,
>         .signal_direction       = true,
>         .pwrreg_clkgate         = true,
>         .busy_detect            = true,
> @@ -171,6 +179,7 @@ static struct variant_data variant_ux500v2 = {
>         .st_clkdiv              = true,
>         .blksz_datactrl16       = true,
>         .pwrreg_powerup         = MCI_PWR_ON,
> +       .f_max                  = 100000000,
>         .signal_direction       = true,
>         .pwrreg_clkgate         = true,
>         .busy_detect            = true,
> @@ -189,6 +198,7 @@ static struct variant_data variant_qcom = {
>         .blksz_datactrl4        = true,
>         .datalength_bits        = 24,
>         .pwrreg_powerup         = MCI_PWR_UP,
> +       .f_max                  = 208000000,
>  };
>
>  static int mmci_card_busy(struct mmc_host *mmc)
> @@ -1485,8 +1495,8 @@ static int mmci_probe(struct amba_device *dev,
>          * so we try to adjust the clock down to this,
>          * (if possible).
>          */
> -       if (host->mclk > 100000000) {
> -               ret = clk_set_rate(host->clk, 100000000);
> +       if (host->mclk > host->variant->f_max) {

You can use the local variant pointer directly, instead of host->variant.

> +               ret = clk_set_rate(host->clk, host->variant->f_max);
>                 if (ret < 0)
>                         goto clk_disable;
>                 host->mclk = clk_get_rate(host->clk);
> --
> 1.9.1
>

Looks good otherwise!

Kind regards
Ulf Hansson
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