Re: [PATCH V7 16/23] mmc: sdhci-uhs2: add clock operations

[Adrian Hunter]

On 31/03/23 13:55, Victor Shih wrote:
> This is a sdhci version of mmc's uhs2_[enable|disable]_clk operations.
> 
> Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
> Signed-off-by: Victor Shih <victor.shih@xxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/mmc/host/sdhci-uhs2.c | 32 ++++++++++++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index e2972be1889f..71ac76065886 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -14,6 +14,7 @@
>  #include <linux/module.h>
>  #include <linux/iopoll.h>
>  #include <linux/bitfield.h>
> +#include <linux/ktime.h>

There is no ktime in this patch

>  
>  #include "sdhci.h"
>  #include "sdhci-uhs2.h"
> @@ -328,6 +329,37 @@ static int sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  	return 0;
>  }
>  
> +static int 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);
> +
> +	return 0;
> +}
> +
> +static int sdhci_uhs2_enable_clk(struct mmc_host *mmc)
> +{
> +	struct sdhci_host *host = mmc_priv(mmc);
> +	u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> +	u32 val;
> +	/* 20ms */
> +	int timeout_us = 20000;

Let's put the comment on the end and put the lines in
descending line length i.e.

	int timeout_us = 20000; /* 20ms */
	u32 val;

> +
> +	clk |= SDHCI_CLOCK_CARD_EN;
> +	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> +	if (read_poll_timeout_atomic(sdhci_readw, val, (val & SDHCI_CLOCK_INT_STABLE),
> +				     10, timeout_us, true, host, SDHCI_CLOCK_CONTROL)) {

atomic does not seem to be needed here

> +		pr_err("%s: Internal clock never stabilised.\n", mmc_hostname(host->mmc));
> +		sdhci_dumpregs(host);
> +		return 1;

		return -EIO;

> +	}
> +	return 0;
> +}
> +
>  /*****************************************************************************\
>   *                                                                           *
>   * Driver init/exit                                                          *