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Message-ID: <5351ec11-8bcd-4ae2-a84e-15d20b15ece2@ti.com>
Date: Tue, 6 Feb 2024 16:16:41 -0600
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Subject: Re: [PATCH v1 3/5] mmc: sdhci_am654: Add missing OTAP/ITAP enable
To: Judith Mendez <jm@ti.com>, Ulf Hansson <ulf.hansson@linaro.org>
CC: Adrian Hunter <adrian.hunter@intel.com>, <linux-mmc@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, Randolph Sapp <rs@ti.com>,
        Vignesh
 Raghavendra <vigneshr@ti.com>
References: <20240131215044.3163469-1-jm@ti.com>
 <20240131215044.3163469-4-jm@ti.com>
 <8cb4d505-77b7-4f63-91b4-f9f8a71df17d@ti.com>
 <51b94d6a-b5e6-428e-81fb-3c21f7fa3d0a@ti.com>
Content-Language: en-US
From: Andrew Davis <afd@ti.com>
In-Reply-To: <51b94d6a-b5e6-428e-81fb-3c21f7fa3d0a@ti.com>
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On 2/6/24 4:00 PM, Judith Mendez wrote:
> Hi Andrew,
> 
> On 2/1/24 1:46 PM, Andrew Davis wrote:
>> On 1/31/24 3:50 PM, Judith Mendez wrote:
>>> Currently the OTAP/ITAP delay enable functionality is missing in
>>> the am654_set_clock function which is used for MMC0 on AM62p
>>> and AM64x devices. The OTAP delay is not enabled when timing <
>>> SDR25 bus speed mode. The ITAP delay is not enabled for all bus
>>> speed modes.
>>>
>>> Add this OTAP/ITAP delay functionality according to the datasheet
>>> [1] OTAPDLYENA and ITAPDLYENA for MMC0.
>>>
>>> [1] https://www.ti.com/lit/ds/symlink/am62p.pdf
>>>
>>> Fixes: 8ee5fc0e0b3b ("mmc: sdhci_am654: Update OTAPDLY writes")
>>> Signed-off-by: Judith Mendez <jm@ti.com>
>>> ---
>>>   drivers/mmc/host/sdhci_am654.c | 48 +++++++++++++++++++---------------
>>>   1 file changed, 27 insertions(+), 21 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
>>> index ff18a274b6f2..5ac82bc70706 100644
>>> --- a/drivers/mmc/host/sdhci_am654.c
>>> +++ b/drivers/mmc/host/sdhci_am654.c
>>> @@ -143,6 +143,7 @@ struct sdhci_am654_data {
>>>       struct regmap *base;
>>>       int otap_del_sel[ARRAY_SIZE(td)];
>>>       int itap_del_sel[ARRAY_SIZE(td)];
>>> +    u8 itap_del_ena[ARRAY_SIZE(td)];
>>
>> Why u8? Seems this is always manipulated as a u32. In fact
>> the same is true for `otap_del_sel` and `itap_del_sel` above.
>> Those needed fixed also.
> 
> Sure, I can fix for v2.
> 
>>
>>>       int clkbuf_sel;
>>>       int trm_icp;
>>>       int drv_strength;
>>> @@ -171,11 +172,13 @@ struct sdhci_am654_driver_data {
>>>   };
>>>   static void sdhci_am654_write_itapdly(struct sdhci_am654_data *sdhci_am654,
>>> -                      u32 itapdly)
>>> +                      u32 itapdly, u32 enable)
>>>   {
>>>       /* 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, ITAPDLYENA_MASK,
>>> +               enable << ITAPDLYENA_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);
>>> @@ -249,7 +252,8 @@ static void sdhci_am654_setup_dll(struct sdhci_host *host, unsigned int clock,
>>>           return;
>>>       }
>>> -    sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing]);
>>> +    sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing],
>>> +                  sdhci_am654->itap_del_ena[timing]);
>>>   }
>>>   static void sdhci_am654_setup_delay_chain(struct sdhci_am654_data *sdhci_am654,
>>> @@ -263,8 +267,8 @@ static void sdhci_am654_setup_delay_chain(struct sdhci_am654_data *sdhci_am654,
>>>       mask = SELDLYTXCLK_MASK | SELDLYRXCLK_MASK;
>>>       regmap_update_bits(sdhci_am654->base, PHY_CTRL5, mask, val);
>>> -    sdhci_am654_write_itapdly(sdhci_am654,
>>> -                  sdhci_am654->itap_del_sel[timing]);
>>> +    sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing],
>>> +                  sdhci_am654->itap_del_ena[timing]);
>>>   }
>>>   static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
>>> @@ -273,20 +277,17 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
>>>       struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
>>>       unsigned char timing = host->mmc->ios.timing;
>>>       u32 otap_del_sel;
>>> -    u32 otap_del_ena;
>>>       u32 mask, val;
>>>       regmap_update_bits(sdhci_am654->base, PHY_CTRL1, ENDLL_MASK, 0);
>>>       sdhci_set_clock(host, clock);
>>> -    /* Setup DLL Output TAP delay */
>>> +    /* Setup Output TAP delay */
>>>       otap_del_sel = sdhci_am654->otap_del_sel[timing];
>>> -    otap_del_ena = (timing > MMC_TIMING_UHS_SDR25) ? 1 : 0;
>>>       mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
>>> -    val = (otap_del_ena << OTAPDLYENA_SHIFT) |
>>> -          (otap_del_sel << OTAPDLYSEL_SHIFT);
>>> +    val = (0x1 << OTAPDLYENA_SHIFT) | (otap_del_sel << OTAPDLYSEL_SHIFT);
>>>       /* Write to STRBSEL for HS400 speed mode */
>>>       if (timing == MMC_TIMING_MMC_HS400) {
>>> @@ -319,14 +320,20 @@ static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host,
>>>       struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
>>>       unsigned char timing = host->mmc->ios.timing;
>>>       u32 otap_del_sel;
>>> +    u32 itap_del_ena;
>>>       u32 mask, val;
>>> -    /* Setup DLL Output TAP delay */
>>> +    /* Setup Output TAP delay */
>>>       otap_del_sel = sdhci_am654->otap_del_sel[timing];
>>>       mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
>>> -    val = (0x1 << OTAPDLYENA_SHIFT) |
>>> -          (otap_del_sel << OTAPDLYSEL_SHIFT);
>>> +    val = (0x1 << OTAPDLYENA_SHIFT) | (otap_del_sel << OTAPDLYSEL_SHIFT);
>>
>> You are not changing anything in this line, so why reformat it? If
>> you want to do some reformatting put it in a separate patch. And in
>> this case, I like it better how it was.
> 
> Ok, I thought it was easier to read, but I can revert for v2.
> 

It might be easier to read, and patches that make the code easier
to read are always welcome. The issue was since you didn't touch
this line as part of what this patch does, cleaning it up should
go in a different patch. Fixups like that make this patch overly
busy.

Andrew

> ~ judith
> 
>>
>> Andrew
>>
>>> +
>>> +    itap_del_ena = sdhci_am654->itap_del_ena[timing];
>>> +
>>> +    mask |= ITAPDLYENA_MASK;
>>> +    val |= (itap_del_ena << ITAPDLYENA_SHIFT);
>>> +
>>>       regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask, val);
>>>       regmap_update_bits(sdhci_am654->base, PHY_CTRL5, CLKBUFSEL_MASK,
>>> @@ -503,12 +510,8 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
>>>       memset(fail_window, 0, sizeof(fail_window[0]) * ITAPDLY_LENGTH);
>>> -    /* Enable ITAPDLY */
>>> -    regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYENA_MASK,
>>> -               1 << ITAPDLYENA_SHIFT);
>>> -
>>>       for (itap = 0; itap < ITAPDLY_LENGTH; itap++) {
>>> -        sdhci_am654_write_itapdly(sdhci_am654, itap);
>>> +        sdhci_am654_write_itapdly(sdhci_am654, itap, 1);
>>>           curr_pass = !mmc_send_tuning(host->mmc, opcode, NULL);
>>> @@ -532,7 +535,7 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
>>>       itap = sdhci_am654_calculate_itap(host, fail_window, fail_index,
>>>                         (sdhci_am654->dll_enable ? true : false));
>>> -    sdhci_am654_write_itapdly(sdhci_am654, itap);
>>> +    sdhci_am654_write_itapdly(sdhci_am654, itap, 1);
>>>       return 0;
>>>   }
>>> @@ -681,9 +684,12 @@ static int sdhci_am654_get_otap_delay(struct sdhci_host *host,
>>>                   host->mmc->caps2 &= ~td[i].capability;
>>>           }
>>> -        if (td[i].itap_binding)
>>> -            device_property_read_u32(dev, td[i].itap_binding,
>>> -                         &sdhci_am654->itap_del_sel[i]);
>>> +        if (td[i].itap_binding) {
>>> +            ret = device_property_read_u32(dev, td[i].itap_binding,
>>> +                               &sdhci_am654->itap_del_sel[i]);
>>> +                if (!ret)
>>> +                    sdhci_am654->itap_del_ena[i] = 0x1;
>>> +        }
>>>       }
>>>       return 0;
>