Re: [RFC PATCH V3 11/21] mmc: sdhci: UHS-II support, export host operations to core

From: Adrian Hunter
Date: Fri Aug 21 2020 - 10:06:38 EST


On 10/07/20 2:10 pm, Ben Chuang wrote:
> From: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
>
> Export sdhci-specific UHS-II operations to core.
>
> Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci.c | 70 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 70 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index c2f6923d296c..aaf41954511a 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2977,6 +2977,70 @@ static void sdhci_card_event(struct mmc_host *mmc)
> spin_unlock_irqrestore(&host->lock, flags);
> }
>
> +#if IS_ENABLED(CONFIG_MMC_SDHCI_UHS2)
> +static int sdhci_uhs2_detect_init(struct mmc_host *mmc)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + int ret;
> +
> + if (sdhci_uhs2_ops.do_detect_init)
> + ret = sdhci_uhs2_ops.do_detect_init(host);
> + else
> + return 0;
> +
> + return ret;
> +}
> +
> +static int sdhci_uhs2_set_reg(struct mmc_host *mmc, enum uhs2_act act)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + int ret;
> +
> + if (sdhci_uhs2_ops.do_set_reg)
> + ret = sdhci_uhs2_ops.do_set_reg(host, act);
> + else
> + ret = 0;
> +
> + return ret;
> +}
> +
> +static void sdhci_uhs2_disable_clk(struct mmc_host *mmc)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> +
> + clk &= ~SDHCI_CLOCK_CARD_EN;
> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +}
> +
> +static void sdhci_uhs2_enable_clk(struct mmc_host *mmc)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> + ktime_t timeout;
> +
> + clk |= SDHCI_CLOCK_CARD_EN;
> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> + /* Wait max 20 ms */
> + timeout = ktime_add_ms(ktime_get(), 20);
> + 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: Internal clock never stabilised.\n",
> + mmc_hostname(host->mmc));
> + sdhci_dumpregs(host);
> + return;
> + }
> + udelay(10);
> + }
> +}
> +#endif /* CONFIG_MMC_SDHCI_UHS2 */

Please put all uhs2 functions in sdhci-uhs2.c and call them through sdhci_ops.

> +
> static const struct mmc_host_ops sdhci_ops = {
> .request = sdhci_request,
> .post_req = sdhci_post_req,
> @@ -2992,6 +3056,12 @@ static const struct mmc_host_ops sdhci_ops = {
> .execute_tuning = sdhci_execute_tuning,
> .card_event = sdhci_card_event,
> .card_busy = sdhci_card_busy,
> +#if IS_ENABLED(CONFIG_MMC_SDHCI_UHS2)
> + .uhs2_detect_init = sdhci_uhs2_detect_init,
> + .uhs2_set_reg = sdhci_uhs2_set_reg,
> + .uhs2_disable_clk = sdhci_uhs2_disable_clk,
> + .uhs2_enable_clk = sdhci_uhs2_enable_clk,
> +#endif /* CONFIG_MMC_SDHCI_UHS2 */
> };
>
> /*****************************************************************************\
>