On 05/10/16 17:40, Ritesh Harjani wrote:
> sdhci-msm controller may have different clk-rates for each
> bus speed mode. Thus implement set_clock callback for
> sdhci-msm driver.
>
> Signed-off-by: Sahitya Tummala <stummala@xxxxxxxxxxxxxx>
> Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-msm.c | 110 ++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 109 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 542ddad..9d18cf0 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -84,6 +84,7 @@ struct sdhci_msm_host {
> struct clk *bus_clk; /* SDHC bus voter clock */
> u32 *clk_table;
> int clk_table_sz;
> + u32 clk_rate;
> struct mmc_host *mmc;
> bool use_14lpp_dll_reset;
> };
> @@ -588,6 +589,113 @@ static unsigned int sdhci_msm_get_min_clock(struct sdhci_host *host)
> }
> }
>
> +static unsigned int sdhci_msm_get_msm_clk_rate(struct sdhci_host *host,
> + u32 req_clk)
> +{
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> + int count;
> + unsigned int sel_clk = -1;
> +
> + if (!msm_host->clk_table)
> + return clk_round_rate(msm_host->clk, ULONG_MAX);
> +
> + count = msm_host->clk_table_sz;
> +
> + while (count--) {
> + sel_clk = msm_host->clk_table[count];
> + if (req_clk >= sel_clk)
> + return sel_clk;
> + }
> +
> + return sel_clk;
> +}
> +
> +/**
> + * __sdhci_msm_set_clock - sdhci_msm clock control.
> + *
> + * Description:
> + * Implement MSM version of sdhci_set_clock.
> + * This is required since MSM controller does not
> + * use internal divider and instead directly control
> + * the GCC clock as per HW recommendation.
> + **/
> +void __sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
> +{
> + u16 clk;
> + unsigned long timeout;
> +
> + /*
> + * Keep actual_clock as zero -
> + * - since there is no divider used so no need of having actual_clock.
> + * - MSM controller uses SDCLK for data timeout calculation. If
> + * actual_clock is zero, host->clock is taken for calculation.
> + */
> + host->mmc->actual_clock = 0;
> +
> + sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
> +
> + if (clock == 0)
> + return;
> +
> + /*
> + * MSM controller do not use clock divider.
> + * Thus read SDHCI_CLOCK_CONTROL and only enable
> + * clock with no divider value programmed.
> + */
> + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> +
> + clk |= SDHCI_CLOCK_INT_EN;
> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> + /* Wait max 20 ms */
> + timeout = 20;
> + while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
> + & SDHCI_CLOCK_INT_STABLE)) {
> + if (timeout == 0) {
> + pr_err("%s: Internal clock never stabilised.\n",
> + mmc_hostname(host->mmc));
> + return;
> + }
> + timeout--;
> + mdelay(1);
> + }
> +
> + clk |= SDHCI_CLOCK_CARD_EN;
> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +}
> +
> +static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
> +{
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> + u32 msm_clock;
> + int rc;
> +
> + if (!clock)
Wouldn't you still need to set msm_host->clk_rate = clock in this case
> + goto out;
> +
> + spin_unlock_irq(&host->lock);
> + if ((clock != msm_host->clk_rate) && msm_host->clk_table) {
> + msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);
> + rc = clk_set_rate(msm_host->clk, msm_clock);
> + if (rc) {
> + pr_err("%s: failed to set clock at rate %u, requested clock rate %u\n",
> + mmc_hostname(host->mmc), msm_clock, clock);
> + goto out;
> + }
> + msm_host->clk_rate = clock;
> + pr_debug("%s: setting clock at rate %lu\n",
> + mmc_hostname(host->mmc), clk_get_rate(msm_host->clk));
> + }
> +
> + spin_lock_irq(&host->lock);
> +out:
> + if (!msm_host->clk_table)
> + return sdhci_set_clock(host, clock);
Could put the above 2 lines at the start and then no need to check
msm_host->clk_table again.
> + __sdhci_msm_set_clock(host, clock);
> +}
> +
> static const struct of_device_id sdhci_msm_dt_match[] = {
> { .compatible = "qcom,sdhci-msm-v4" },
> {},
> @@ -598,7 +706,7 @@ MODULE_DEVICE_TABLE(of, sdhci_msm_dt_match);
> static const struct sdhci_ops sdhci_msm_ops = {
> .platform_execute_tuning = sdhci_msm_execute_tuning,
> .reset = sdhci_reset,
> - .set_clock = sdhci_set_clock,
> + .set_clock = sdhci_msm_set_clock,
> .get_min_clock = sdhci_msm_get_min_clock,
> .get_max_clock = sdhci_msm_get_max_clock,
> .set_bus_width = sdhci_set_bus_width,
>
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