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SubjectRe: [PATCH V5 2/4] mmc: sdhci: Add PLL Enable support to internal clock setup
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On 20/08/19 5:06 AM, Ben Chuang wrote:
> From: Ben Chuang <ben.chuang@genesyslogic.com.tw>
>
> 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.
>
> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> Co-developed-by: Michael K Johnson <johnsonm@danlj.org>
> Signed-off-by: Michael K Johnson <johnsonm@danlj.org>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
> drivers/mmc/host/sdhci.c | 23 +++++++++++++++++++++++
> drivers/mmc/host/sdhci.h | 1 +
> 2 files changed, 24 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index bed0760a6c2a..9106ebc7a422 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1653,6 +1653,29 @@ void sdhci_enable_clk(struct sdhci_host *host, u16 clk)
> udelay(10);
> }
>
> + 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;
> + }
> + udelay(10);
> + }
> + }
> +
> clk |= SDHCI_CLOCK_CARD_EN;
> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> }
> 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
>
>

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