lkml.org 
[lkml]   [2024]   [Feb]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH v1 2/5] mmc: sdhci_am654: Write ITAPDLY for DDR52 timing
From
Hi Andrew,

On 2/1/24 1:36 PM, Andrew Davis wrote:
> On 1/31/24 3:50 PM, Judith Mendez wrote:
>> For DDR52 timing, DLL is enabled but tuning is not carried
>> out, therefore the ITAPDLY value in PHY CTRL 4 register is
>> not correct. Fix this by writing ITAPDLY after enabling DLL.
>>
>> Fixes: a161c45f2979 ("mmc: sdhci_am654: Enable DLL only for some speed
>> modes")
>> Signed-off-by: Judith Mendez <jm@ti.com>
>> ---
>>   drivers/mmc/host/sdhci_am654.c | 27 +++++++++++++++------------
>>   1 file changed, 15 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci_am654.c
>> b/drivers/mmc/host/sdhci_am654.c
>> index a3798c9912f6..ff18a274b6f2 100644
>> --- a/drivers/mmc/host/sdhci_am654.c
>> +++ b/drivers/mmc/host/sdhci_am654.c
>> @@ -170,7 +170,19 @@ struct sdhci_am654_driver_data {
>>   #define DLL_CALIB    (1 << 4)
>>   };
>> -static void sdhci_am654_setup_dll(struct sdhci_host *host, unsigned
>> int clock)
>> +static void sdhci_am654_write_itapdly(struct sdhci_am654_data
>> *sdhci_am654,
>> +                      u32 itapdly)
>
> This patch is confusing, looks like you switched the place of these two
> functions, but diff is not really liking that. You can mess with
> --diff-algorithm and the like to get a more readable patch. But in
> this case why switch their spots at all?
>
> Seems to be so you can call sdhci_am654_write_itapdly() from
> sdhci_am654_setup_dll() without a forward declaration, instead
> why not just call sdhci_am654_write_itapdly() after calling
> sdhci_am654_setup_dll() below. That also saves to from having
> to pass in `timing` to sdhci_am654_write_itapdly() just to
> have it pass it right through to sdhci_am654_setup_dll().

Really the only reason I did this is because we call
sdhci_am654_write_itapdly() in sdhci_am654_setup_delay_chain and
I wanted to keep the flow for setting up DLL the same.
I agree the patch looks confusing, so I will fix this for v2.

~ Judith

> Andrew
>
>> +{
>> +    /* Set ITAPCHGWIN before writing to ITAPDLY */
>> +    regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPCHGWIN_MASK,
>> +               0x1 << ITAPCHGWIN_SHIFT);
>> +    regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYSEL_MASK,
>> +               itapdly << ITAPDLYSEL_SHIFT);
>> +    regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPCHGWIN_MASK,
>> 0);
>> +}
>> +
>> +static void sdhci_am654_setup_dll(struct sdhci_host *host, unsigned
>> int clock,
>> +                  unsigned char timing)
>>   {
>>       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>       struct sdhci_am654_data *sdhci_am654 =
>> sdhci_pltfm_priv(pltfm_host);
>> @@ -236,17 +248,8 @@ static void sdhci_am654_setup_dll(struct
>> sdhci_host *host, unsigned int clock)
>>           dev_err(mmc_dev(host->mmc), "DLL failed to relock\n");
>>           return;
>>       }
>> -}
>> -static void sdhci_am654_write_itapdly(struct sdhci_am654_data
>> *sdhci_am654,
>> -                      u32 itapdly)
>> -{
>> -    /* Set ITAPCHGWIN before writing to ITAPDLY */
>> -    regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPCHGWIN_MASK,
>> -               1 << ITAPCHGWIN_SHIFT);
>> -    regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYSEL_MASK,
>> -               itapdly << ITAPDLYSEL_SHIFT);
>> -    regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPCHGWIN_MASK,
>> 0);
>> +    sdhci_am654_write_itapdly(sdhci_am654,
>> sdhci_am654->itap_del_sel[timing]);
>>   }
>>   static void sdhci_am654_setup_delay_chain(struct sdhci_am654_data
>> *sdhci_am654,
>> @@ -298,7 +301,7 @@ static void sdhci_am654_set_clock(struct
>> sdhci_host *host, unsigned int clock)
>>       regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask, val);
>>       if (timing > MMC_TIMING_UHS_SDR25 && clock >= CLOCK_TOO_SLOW_HZ) {
>> -        sdhci_am654_setup_dll(host, clock);
>> +        sdhci_am654_setup_dll(host, clock, timing);
>>           sdhci_am654->dll_enable = true;
>>       } else {
>>           sdhci_am654_setup_delay_chain(sdhci_am654, timing);


\
 
 \ /
  Last update: 2024-05-27 14:51    [W:0.047 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site