RE: [PATCH] mmc: sdhci-of-arasan: Allow configuring zero tap values

[Manish Narani]

Hi,

> -----Original Message-----
> From: Manish Narani <manish.narani@xxxxxxxxxx>
> Sent: Tuesday, November 10, 2020 11:12 PM
> To: Michal Simek <michals@xxxxxxxxxx>; adrian.hunter@xxxxxxxxx;
> ulf.hansson@xxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; git <git@xxxxxxxxxx>; Manish Narani
> <MNARANI@xxxxxxxxxx>; Sai Krishna Potthuri <lakshmis@xxxxxxxxxx>
> Subject: [PATCH] mmc: sdhci-of-arasan: Allow configuring zero tap values
> 
> Allow configuring the Output and Input tap values with zero to avoid
> failures in some cases (one of them is SD boot mode) where the output
> and input tap values may be already set to non-zero.
> 

Fixes: a5c8b2ae2e51 ("mmc: sdhci-of-arasan: Add support for ZynqMP Platform Tap Delays Setup")

> Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xxxxxxxxxx>
> Signed-off-by: Manish Narani <manish.narani@xxxxxxxxxx>
> ---
>  drivers/mmc/host/sdhci-of-arasan.c | 40 ++++++------------------------
>  1 file changed, 8 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-
> of-arasan.c
> index 829ccef87426..100621e55427 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -600,14 +600,8 @@ static int sdhci_zynqmp_sdcardclk_set_phase(struct
> clk_hw *hw, int degrees)
>  	u8 tap_delay, tap_max = 0;
>  	int ret;
> 
> -	/*
> -	 * This is applicable for SDHCI_SPEC_300 and above
> -	 * ZynqMP does not set phase for <=25MHz clock.
> -	 * If degrees is zero, no need to do anything.
> -	 */
> -	if (host->version < SDHCI_SPEC_300 ||
> -	    host->timing == MMC_TIMING_LEGACY ||
> -	    host->timing == MMC_TIMING_UHS_SDR12 || !degrees)
> +	/* This is applicable for SDHCI_SPEC_300 and above */
> +	if (host->version < SDHCI_SPEC_300)
>  		return 0;
> 
>  	switch (host->timing) {
> @@ -668,14 +662,8 @@ static int
> sdhci_zynqmp_sampleclk_set_phase(struct clk_hw *hw, int degrees)
>  	u8 tap_delay, tap_max = 0;
>  	int ret;
> 
> -	/*
> -	 * This is applicable for SDHCI_SPEC_300 and above
> -	 * ZynqMP does not set phase for <=25MHz clock.
> -	 * If degrees is zero, no need to do anything.
> -	 */
> -	if (host->version < SDHCI_SPEC_300 ||
> -	    host->timing == MMC_TIMING_LEGACY ||
> -	    host->timing == MMC_TIMING_UHS_SDR12 || !degrees)
> +	/* This is applicable for SDHCI_SPEC_300 and above */
> +	if (host->version < SDHCI_SPEC_300)
>  		return 0;
> 
>  	switch (host->timing) {
> @@ -733,14 +721,8 @@ static int sdhci_versal_sdcardclk_set_phase(struct
> clk_hw *hw, int degrees)
>  	struct sdhci_host *host = sdhci_arasan->host;
>  	u8 tap_delay, tap_max = 0;
> 
> -	/*
> -	 * This is applicable for SDHCI_SPEC_300 and above
> -	 * Versal does not set phase for <=25MHz clock.
> -	 * If degrees is zero, no need to do anything.
> -	 */
> -	if (host->version < SDHCI_SPEC_300 ||
> -	    host->timing == MMC_TIMING_LEGACY ||
> -	    host->timing == MMC_TIMING_UHS_SDR12 || !degrees)
> +	/* This is applicable for SDHCI_SPEC_300 and above */
> +	if (host->version < SDHCI_SPEC_300)
>  		return 0;
> 
>  	switch (host->timing) {
> @@ -804,14 +786,8 @@ static int sdhci_versal_sampleclk_set_phase(struct
> clk_hw *hw, int degrees)
>  	struct sdhci_host *host = sdhci_arasan->host;
>  	u8 tap_delay, tap_max = 0;
> 
> -	/*
> -	 * This is applicable for SDHCI_SPEC_300 and above
> -	 * Versal does not set phase for <=25MHz clock.
> -	 * If degrees is zero, no need to do anything.
> -	 */
> -	if (host->version < SDHCI_SPEC_300 ||
> -	    host->timing == MMC_TIMING_LEGACY ||
> -	    host->timing == MMC_TIMING_UHS_SDR12 || !degrees)
> +	/* This is applicable for SDHCI_SPEC_300 and above */
> +	if (host->version < SDHCI_SPEC_300)
>  		return 0;
> 
>  	switch (host->timing) {
> --
> 2.17.1

Thanks,
Manish