diff mbox

[v4,8/9] mmc: sdhci-msm: Add clock changes for DDR mode.

Message ID 1472033024-14890-9-git-send-email-riteshh@codeaurora.org (mailing list archive)
State New, archived
Headers show

Commit Message

Ritesh Harjani Aug. 24, 2016, 10:03 a.m. UTC
SDHC MSM controller need 2x clock for MCLK at GCC.
Hence make required changes to have 2x clock for
DDR timing modes.

Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
---
 drivers/mmc/host/sdhci-msm.c | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

Comments

Adrian Hunter Aug. 29, 2016, 1:17 p.m. UTC | #1
On 24/08/16 13:03, Ritesh Harjani wrote:
> SDHC MSM controller need 2x clock for MCLK at GCC.
> Hence make required changes to have 2x clock for
> DDR timing modes.
> 
> Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
> ---
>  drivers/mmc/host/sdhci-msm.c | 22 ++++++++++++++++++----
>  1 file changed, 18 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 853639b..538594c 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -667,21 +667,35 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>  	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> -	u32 msm_clock = 0;
> +	struct mmc_ios curr_ios = host->mmc->ios;
> +	u32 msm_clock, ddr_clock;
>  	int rc = 0;
>  
>  	if (!clock)
>  		goto out;
>  
> -	if (clock != msm_host->clk_rate) {
> -		msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);
> +	msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);
> +	if ((curr_ios.timing == MMC_TIMING_UHS_DDR50) ||
> +		(curr_ios.timing == MMC_TIMING_MMC_DDR52) ||
> +		(curr_ios.timing == MMC_TIMING_MMC_HS400)) {
> +		/*
> +		 * The SDHC requires internal clock frequency to be double the
> +		 * actual clock that will be set for DDR mode. The controller
> +		 * uses the faster clock(100/400MHz) for some of its parts and
> +		 * send the actual required clock (50/200MHz) to the card.
> +		 */
> +		ddr_clock = clock * 2;
> +		msm_clock = sdhci_msm_get_msm_clk_rate(host, ddr_clock);
> +	}
> +

Could be slightly simpler e.g.

	if ((curr_ios.timing == MMC_TIMING_UHS_DDR50) ||
	    (curr_ios.timing == MMC_TIMING_MMC_DDR52) ||
	    (curr_ios.timing == MMC_TIMING_MMC_HS400)) {
		/*
		 * The SDHC requires internal clock frequency to be double the
		 * actual clock that will be set for DDR mode. The controller
		 * uses the faster clock(100/400MHz) for some of its parts and
		 * send the actual required clock (50/200MHz) to the card.
		 */
		clock *= 2;
	}
	msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);


> +	if (msm_clock != msm_host->clk_rate) {
>  		rc = clk_set_rate(msm_host->clk, msm_clock);
>  		if (rc) {
>  			pr_err("%s: failed to set clock at rate %u, requested clock rate %u\n",
>  				mmc_hostname(host->mmc), msm_clock, clock);
>  			goto out;
>  		}
> -		msm_host->clk_rate = clock;
> +		msm_host->clk_rate = msm_clock;
>  		pr_debug("%s: setting clock at rate %lu\n",
>  			mmc_hostname(host->mmc), clk_get_rate(msm_host->clk));
>  	}
> 

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Ritesh Harjani Aug. 30, 2016, 2:16 p.m. UTC | #2
Hi Adrian,


On 8/29/2016 6:47 PM, Adrian Hunter wrote:
> On 24/08/16 13:03, Ritesh Harjani wrote:
>> SDHC MSM controller need 2x clock for MCLK at GCC.
>> Hence make required changes to have 2x clock for
>> DDR timing modes.
>>
>> Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
>> ---
>>  drivers/mmc/host/sdhci-msm.c | 22 ++++++++++++++++++----
>>  1 file changed, 18 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>> index 853639b..538594c 100644
>> --- a/drivers/mmc/host/sdhci-msm.c
>> +++ b/drivers/mmc/host/sdhci-msm.c
>> @@ -667,21 +667,35 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
>>  {
>>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>  	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>> -	u32 msm_clock = 0;
>> +	struct mmc_ios curr_ios = host->mmc->ios;
>> +	u32 msm_clock, ddr_clock;
>>  	int rc = 0;
>>
>>  	if (!clock)
>>  		goto out;
>>
>> -	if (clock != msm_host->clk_rate) {
>> -		msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);
>> +	msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);
>> +	if ((curr_ios.timing == MMC_TIMING_UHS_DDR50) ||
>> +		(curr_ios.timing == MMC_TIMING_MMC_DDR52) ||
>> +		(curr_ios.timing == MMC_TIMING_MMC_HS400)) {
>> +		/*
>> +		 * The SDHC requires internal clock frequency to be double the
>> +		 * actual clock that will be set for DDR mode. The controller
>> +		 * uses the faster clock(100/400MHz) for some of its parts and
>> +		 * send the actual required clock (50/200MHz) to the card.
>> +		 */
>> +		ddr_clock = clock * 2;
>> +		msm_clock = sdhci_msm_get_msm_clk_rate(host, ddr_clock);
>> +	}
>> +
>
> Could be slightly simpler e.g.
>
> 	if ((curr_ios.timing == MMC_TIMING_UHS_DDR50) ||
> 	    (curr_ios.timing == MMC_TIMING_MMC_DDR52) ||
> 	    (curr_ios.timing == MMC_TIMING_MMC_HS400)) {
> 		/*
> 		 * The SDHC requires internal clock frequency to be double the
> 		 * actual clock that will be set for DDR mode. The controller
> 		 * uses the faster clock(100/400MHz) for some of its parts and
> 		 * send the actual required clock (50/200MHz) to the card.
> 		 */
> 		clock *= 2;
> 	}
> 	msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);
Sure. Done.

>
>
>> +	if (msm_clock != msm_host->clk_rate) {
>>  		rc = clk_set_rate(msm_host->clk, msm_clock);
>>  		if (rc) {
>>  			pr_err("%s: failed to set clock at rate %u, requested clock rate %u\n",
>>  				mmc_hostname(host->mmc), msm_clock, clock);
>>  			goto out;
>>  		}
>> -		msm_host->clk_rate = clock;
>> +		msm_host->clk_rate = msm_clock;
>>  		pr_debug("%s: setting clock at rate %lu\n",
>>  			mmc_hostname(host->mmc), clk_get_rate(msm_host->clk));
>>  	}
>>
>
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diff mbox

Patch

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 853639b..538594c 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -667,21 +667,35 @@  static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
-	u32 msm_clock = 0;
+	struct mmc_ios curr_ios = host->mmc->ios;
+	u32 msm_clock, ddr_clock;
 	int rc = 0;
 
 	if (!clock)
 		goto out;
 
-	if (clock != msm_host->clk_rate) {
-		msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);
+	msm_clock = sdhci_msm_get_msm_clk_rate(host, clock);
+	if ((curr_ios.timing == MMC_TIMING_UHS_DDR50) ||
+		(curr_ios.timing == MMC_TIMING_MMC_DDR52) ||
+		(curr_ios.timing == MMC_TIMING_MMC_HS400)) {
+		/*
+		 * The SDHC requires internal clock frequency to be double the
+		 * actual clock that will be set for DDR mode. The controller
+		 * uses the faster clock(100/400MHz) for some of its parts and
+		 * send the actual required clock (50/200MHz) to the card.
+		 */
+		ddr_clock = clock * 2;
+		msm_clock = sdhci_msm_get_msm_clk_rate(host, ddr_clock);
+	}
+
+	if (msm_clock != msm_host->clk_rate) {
 		rc = clk_set_rate(msm_host->clk, msm_clock);
 		if (rc) {
 			pr_err("%s: failed to set clock at rate %u, requested clock rate %u\n",
 				mmc_hostname(host->mmc), msm_clock, clock);
 			goto out;
 		}
-		msm_host->clk_rate = clock;
+		msm_host->clk_rate = msm_clock;
 		pr_debug("%s: setting clock at rate %lu\n",
 			mmc_hostname(host->mmc), clk_get_rate(msm_host->clk));
 	}