On 26/07/19 5:07 AM, Michael K. Johnson wrote:
> The GL9750 and GL9755 chipsets, and possibly others, require PLL Enable
> setup as part of the internal clock setup as described in 3.2.1 Internal
> Clock Setup Sequence of SD Host Controller Simplified Specification
> Version 4.20. This changes the timeouts to the new specification of
> 150ms for each step and is documented as safe for "prior versions which
> do not support PLL Enable."
>
> Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
> Co-developed-by: Michael K Johnson <johnsonm@xxxxxxxxx>
> Signed-off-by: Michael K Johnson <johnsonm@xxxxxxxxx>
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 59acf8e3331e..14957578bf2e 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1636,8 +1636,8 @@ void sdhci_enable_clk(struct sdhci_host *host, u16 clk)
> clk |= SDHCI_CLOCK_INT_EN;
> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
>
> - /* Wait max 20 ms */
> - timeout = ktime_add_ms(ktime_get(), 20);
> + /* Wait max 150 ms */
> + timeout = ktime_add_ms(ktime_get(), 150);
> while (1) {
> bool timedout = ktime_after(ktime_get(), timeout);
>
> @@ -1650,7 +1650,28 @@ void sdhci_enable_clk(struct sdhci_host *host, u16 clk)
> sdhci_dumpregs(host);
> return;
> }
> - udelay(10);
> + usleep_range(10,15);
There is still one place that calls ->set_clock() under spinlock, so that
needs to stay udelay(10) for now.
> + }
> +
PLL Enable is only valid from v4.1 i.e.
if (host->version >= SDHCI_SPEC_410 && host->v4_mode)
> + clk |= SDHCI_CLOCK_PLL_EN;
> + clk &= ~SDHCI_CLOCK_INT_STABLE;
> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> + /* Wait max 150 ms */
> + timeout = ktime_add_ms(ktime_get(), 150);
> + while (1) {
> + bool timedout = ktime_after(ktime_get(), timeout);
> +
> + clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> + if (clk & SDHCI_CLOCK_INT_STABLE)
> + break;
> + if (timedout) {
> + pr_err("%s: PLL clock never stabilised.\n",
> + mmc_hostname(host->mmc));
> + sdhci_dumpregs(host);
> + return;
> + }
> + usleep_range(10,15);
> }
>
> clk |= SDHCI_CLOCK_CARD_EN;
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 199712e7adbb..72601a4d2e95 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -114,6 +114,7 @@
> #define SDHCI_DIV_HI_MASK 0x300
> #define SDHCI_PROG_CLOCK_MODE 0x0020
> #define SDHCI_CLOCK_CARD_EN 0x0004
> +#define SDHCI_CLOCK_PLL_EN 0x0008
> #define SDHCI_CLOCK_INT_STABLE 0x0002
> #define SDHCI_CLOCK_INT_EN 0x0001
>
>
