Re: [PATCH v3 1/2] mmc: sdhci-of-at91: factor out clks and presets setting
From: Ulf Hansson
Date: Thu Jul 13 2017 - 06:06:28 EST
On 13 July 2017 at 10:04, Quentin Schulz
<quentin.schulz@xxxxxxxxxxxxxxxxxx> wrote:
> The setting of clocks and presets is currently done in probe only but
> once deep PM support is added, it'll be needed in the resume function.
>
> Let's create a function for this setting.
>
> Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx>
> Acked-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>
> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Thanks, applied for next!
Kind regards
Uffe
> ---
> drivers/mmc/host/sdhci-of-at91.c | 147 ++++++++++++++++++++++-----------------
> 1 file changed, 82 insertions(+), 65 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index 7611fd679f1a..fb8c6011f13d 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -128,6 +128,84 @@ static const struct of_device_id sdhci_at91_dt_match[] = {
> };
> MODULE_DEVICE_TABLE(of, sdhci_at91_dt_match);
>
> +static int sdhci_at91_set_clks_presets(struct device *dev)
> +{
> + struct sdhci_host *host = dev_get_drvdata(dev);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
> + int ret;
> + unsigned int caps0, caps1;
> + unsigned int clk_base, clk_mul;
> + unsigned int gck_rate, real_gck_rate;
> + unsigned int preset_div;
> +
> + /*
> + * The mult clock is provided by as a generated clock by the PMC
> + * controller. In order to set the rate of gck, we have to get the
> + * base clock rate and the clock mult from capabilities.
> + */
> + clk_prepare_enable(priv->hclock);
> + caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
> + caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
> + clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
> + clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT;
> + gck_rate = clk_base * 1000000 * (clk_mul + 1);
> + ret = clk_set_rate(priv->gck, gck_rate);
> + if (ret < 0) {
> + dev_err(dev, "failed to set gck");
> + clk_disable_unprepare(priv->hclock);
> + return ret;
> + }
> + /*
> + * We need to check if we have the requested rate for gck because in
> + * some cases this rate could be not supported. If it happens, the rate
> + * is the closest one gck can provide. We have to update the value
> + * of clk mul.
> + */
> + real_gck_rate = clk_get_rate(priv->gck);
> + if (real_gck_rate != gck_rate) {
> + clk_mul = real_gck_rate / (clk_base * 1000000) - 1;
> + caps1 &= (~SDHCI_CLOCK_MUL_MASK);
> + caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) &
> + SDHCI_CLOCK_MUL_MASK);
> + /* Set capabilities in r/w mode. */
> + writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN,
> + host->ioaddr + SDMMC_CACR);
> + writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
> + /* Set capabilities in ro mode. */
> + writel(0, host->ioaddr + SDMMC_CACR);
> + dev_info(dev, "update clk mul to %u as gck rate is %u Hz\n",
> + clk_mul, real_gck_rate);
> + }
> +
> + /*
> + * We have to set preset values because it depends on the clk_mul
> + * value. Moreover, SDR104 is supported in a degraded mode since the
> + * maximum sd clock value is 120 MHz instead of 208 MHz. For that
> + * reason, we need to use presets to support SDR104.
> + */
> + preset_div = DIV_ROUND_UP(real_gck_rate, 24000000) - 1;
> + writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> + host->ioaddr + SDHCI_PRESET_FOR_SDR12);
> + preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
> + writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> + host->ioaddr + SDHCI_PRESET_FOR_SDR25);
> + preset_div = DIV_ROUND_UP(real_gck_rate, 100000000) - 1;
> + writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> + host->ioaddr + SDHCI_PRESET_FOR_SDR50);
> + preset_div = DIV_ROUND_UP(real_gck_rate, 120000000) - 1;
> + writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> + host->ioaddr + SDHCI_PRESET_FOR_SDR104);
> + preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
> + writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> + host->ioaddr + SDHCI_PRESET_FOR_DDR50);
> +
> + clk_prepare_enable(priv->mainck);
> + clk_prepare_enable(priv->gck);
> +
> + return 0;
> +}
> +
> #ifdef CONFIG_PM
> static int sdhci_at91_runtime_suspend(struct device *dev)
> {
> @@ -192,11 +270,7 @@ static int sdhci_at91_probe(struct platform_device *pdev)
> struct sdhci_host *host;
> struct sdhci_pltfm_host *pltfm_host;
> struct sdhci_at91_priv *priv;
> - unsigned int caps0, caps1;
> - unsigned int clk_base, clk_mul;
> - unsigned int gck_rate, real_gck_rate;
> int ret;
> - unsigned int preset_div;
>
> match = of_match_device(sdhci_at91_dt_match, &pdev->dev);
> if (!match)
> @@ -228,66 +302,9 @@ static int sdhci_at91_probe(struct platform_device *pdev)
> return PTR_ERR(priv->gck);
> }
>
> - /*
> - * The mult clock is provided by as a generated clock by the PMC
> - * controller. In order to set the rate of gck, we have to get the
> - * base clock rate and the clock mult from capabilities.
> - */
> - clk_prepare_enable(priv->hclock);
> - caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
> - caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
> - clk_base = (caps0 & SDHCI_CLOCK_V3_BASE_MASK) >> SDHCI_CLOCK_BASE_SHIFT;
> - clk_mul = (caps1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT;
> - gck_rate = clk_base * 1000000 * (clk_mul + 1);
> - ret = clk_set_rate(priv->gck, gck_rate);
> - if (ret < 0) {
> - dev_err(&pdev->dev, "failed to set gck");
> - goto hclock_disable_unprepare;
> - }
> - /*
> - * We need to check if we have the requested rate for gck because in
> - * some cases this rate could be not supported. If it happens, the rate
> - * is the closest one gck can provide. We have to update the value
> - * of clk mul.
> - */
> - real_gck_rate = clk_get_rate(priv->gck);
> - if (real_gck_rate != gck_rate) {
> - clk_mul = real_gck_rate / (clk_base * 1000000) - 1;
> - caps1 &= (~SDHCI_CLOCK_MUL_MASK);
> - caps1 |= ((clk_mul << SDHCI_CLOCK_MUL_SHIFT) & SDHCI_CLOCK_MUL_MASK);
> - /* Set capabilities in r/w mode. */
> - writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN, host->ioaddr + SDMMC_CACR);
> - writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
> - /* Set capabilities in ro mode. */
> - writel(0, host->ioaddr + SDMMC_CACR);
> - dev_info(&pdev->dev, "update clk mul to %u as gck rate is %u Hz\n",
> - clk_mul, real_gck_rate);
> - }
> -
> - /*
> - * We have to set preset values because it depends on the clk_mul
> - * value. Moreover, SDR104 is supported in a degraded mode since the
> - * maximum sd clock value is 120 MHz instead of 208 MHz. For that
> - * reason, we need to use presets to support SDR104.
> - */
> - preset_div = DIV_ROUND_UP(real_gck_rate, 24000000) - 1;
> - writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> - host->ioaddr + SDHCI_PRESET_FOR_SDR12);
> - preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
> - writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> - host->ioaddr + SDHCI_PRESET_FOR_SDR25);
> - preset_div = DIV_ROUND_UP(real_gck_rate, 100000000) - 1;
> - writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> - host->ioaddr + SDHCI_PRESET_FOR_SDR50);
> - preset_div = DIV_ROUND_UP(real_gck_rate, 120000000) - 1;
> - writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> - host->ioaddr + SDHCI_PRESET_FOR_SDR104);
> - preset_div = DIV_ROUND_UP(real_gck_rate, 50000000) - 1;
> - writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
> - host->ioaddr + SDHCI_PRESET_FOR_DDR50);
> -
> - clk_prepare_enable(priv->mainck);
> - clk_prepare_enable(priv->gck);
> + ret = sdhci_at91_set_clks_presets(&pdev->dev);
> + if (ret)
> + goto sdhci_pltfm_free;
>
> ret = mmc_of_parse(host->mmc);
> if (ret)
> @@ -335,8 +352,8 @@ static int sdhci_at91_probe(struct platform_device *pdev)
> clocks_disable_unprepare:
> clk_disable_unprepare(priv->gck);
> clk_disable_unprepare(priv->mainck);
> -hclock_disable_unprepare:
> clk_disable_unprepare(priv->hclock);
> +sdhci_pltfm_free:
> sdhci_pltfm_free(pdev);
> return ret;
> }
> --
> 2.11.0
>