On 10/10/16 13:16, Adrian Hunter wrote:
> 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;
'goto out' leaves spinlock unlocked
>> + }
>> + 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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