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

Ulf Hansson
2014-05-30T10:28:36Z

On 28 May 2014 15:47, <srinivas.kandagatla@linaro.org> wrote:
> From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>
> 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@linaro.org>
> ---
> 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