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 <1534406064-10065-8-git-send-email-zhang.chunyan@linaro.org> <0dc112ca-1c01-d8ae-c6f0-80492264f5a4@intel.com>
From:   Chunyan Zhang <zhang.lyra@gmail.com>
Date:   Fri, 24 Aug 2018 14:52:49 +0800
Message-ID: <CAAfSe-uZ3ghR+8dZ7CD03UnGX2Uf1fv=-5s656ZkybcU8LWzJQ@mail.gmail.com>
Subject: Re: [PATCH V5 07/10] mmc: sdhci: Add Auto CMD Auto Select support
To:     Adrian Hunter <adrian.hunter@intel.com>
Cc:     Chunyan Zhang <zhang.chunyan@linaro.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        linux-mmc@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Orson Zhai <orsonzhai@gmail.com>,
        Baolin Wang <baolin.wang@linaro.org>,
        Billows Wu <billows.wu@unisoc.com>,
        Jason Wu <jason.wu@unisoc.com>
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Sender: linux-kernel-owner@vger.kernel.org
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On 23 August 2018 at 20:55, Adrian Hunter <adrian.hunter@intel.com> wrote:
> On 16/08/18 10:54, Chunyan Zhang wrote:
>> As SD Host Controller Specification v4.10 documents:
>> Host Controller Version 4.10 defines this "Auto CMD Auto Select" mode.
>> Selection of Auto CMD depends on setting of CMD23 Enable in the Host
>> Control 2 register which indicates whether card supports CMD23. If CMD23
>> Enable =1, Auto CMD23 is used and if CMD23 Enable =0, Auto CMD12 is
>> used. In case of Version 4.10 or later, use of Auto CMD Auto Select is
>> recommended rather than use of Auto CMD12 Enable or Auto CMD23
>> Enable.
>>
>> This patch add this new mode support.
>>
>> Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
>> ---
>>  drivers/mmc/host/sdhci.c | 67 ++++++++++++++++++++++++++++++++++++++++--------
>>  drivers/mmc/host/sdhci.h |  2 ++
>>  2 files changed, 58 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index a72ad0d..06c2ae9 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -312,6 +312,23 @@ static void sdhci_config_dma(struct sdhci_host *host)
>>       sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
>>  }
>>
>> +static void sdhci_enable_cmd23(struct sdhci_host *host)
>> +{
>> +     u16 ctrl2;
>> +
>> +     /*
>> +      * This is used along with "Auto CMD Auto Select" feature,
>> +      * which is introduced from v4.10, if card supports CMD23,
>> +      * Auto CMD23 should be used instead of Auto CMD12.
>> +      */
>> +     if (host->version >= SDHCI_SPEC_410 &&
>> +         (host->mmc->caps & MMC_CAP_CMD23)) {
>
> The caller has already checked those conditions
>
>> +             ctrl2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> +             ctrl2 |= SDHCI_CMD23_ENABLE;
>> +             sdhci_writew(host, ctrl2, SDHCI_HOST_CONTROL2);
>> +     }
>> +}
>> +
>>  static void sdhci_init(struct sdhci_host *host, int soft)
>>  {
>>       struct mmc_host *mmc = host->mmc;
>> @@ -1095,6 +1112,44 @@ static inline bool sdhci_auto_cmd12(struct sdhci_host *host,
>>              !mrq->cap_cmd_during_tfr;
>>  }
>>
>> +static inline void sdhci_auto_cmd_select(struct sdhci_host *host,
>> +                                      struct mmc_command *cmd,
>> +                                      u16 *mode)
>> +{
>> +     bool use_cmd12 = sdhci_auto_cmd12(host, cmd->mrq) &&
>> +                      (cmd->opcode != SD_IO_RW_EXTENDED);
>> +     bool use_cmd23 = cmd->mrq->sbc && (host->flags & SDHCI_AUTO_CMD23);
>> +
>> +     /*
>> +      * In case of Version 4.10 or later, use of 'Auto CMD Auto
>> +      * Select' is recommended rather than use of 'Auto CMD12
>> +      * Enable' or 'Auto CMD23 Enable'.
>> +      */
>> +     if (host->version >= SDHCI_SPEC_410 && (use_cmd12 || use_cmd23)) {
>> +             *mode |= SDHCI_TRNS_AUTO_SEL;
>> +             /*
>> +              * Note no need to set SDHCI_ARGUMENT2 here, since for version
>> +              * 4.10 and aboves, it doesn't support stuff bits of CMD23
>> +              * argument but only number of blocks which have been set
>> +              * already during prepare data.
>
> The argument will only have already been written in v4_mode.

It seems that we still need to set SDHCI_ARGUMENT2 here, if adding a
quirk for broken using 32-bit block count and also moved below to
sdhci-sprd.c

"
+     /*
+      * For version 4.10 and above, ARGUMENT2 register is also used as 32-bit
+      * block count register which don't support stuff bits of CMD23 argument
+      */
+     if (host->version >= SDHCI_SPEC_410 &&
+         mrq->sbc && (mrq->sbc->arg & SDHCI_ARG2_STUFF) &&
+         (host->flags & SDHCI_AUTO_CMD23))
+             host->flags &= ~SDHCI_AUTO_CMD23
"

>
>> +              */
>> +             if (use_cmd23)
>> +                     sdhci_enable_cmd23(host);
>
> Need to ensure that SDHCI_CMD23_ENABLE is cleared for !use_cmd23
>
>> +             return;
>> +     }
>> +
>> +     /*
>> +      * If we are sending CMD23, CMD12 never gets sent
>> +      * on successful completion (so no Auto-CMD12).
>> +      */
>> +     if (use_cmd12) {
>> +             *mode |= SDHCI_TRNS_AUTO_CMD12;
>> +     } else if (use_cmd23) {
>> +             *mode |= SDHCI_TRNS_AUTO_CMD23;
>> +             sdhci_writel(host, cmd->mrq->sbc->arg, SDHCI_ARGUMENT2);
>> +     }
>> +}
>> +
>>  static void sdhci_set_transfer_mode(struct sdhci_host *host,
>>       struct mmc_command *cmd)
>>  {
>> @@ -1121,17 +1176,7 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
>>
>>       if (mmc_op_multi(cmd->opcode) || data->blocks > 1) {
>>               mode = SDHCI_TRNS_BLK_CNT_EN | SDHCI_TRNS_MULTI;
>> -             /*
>> -              * If we are sending CMD23, CMD12 never gets sent
>> -              * on successful completion (so no Auto-CMD12).
>> -              */
>> -             if (sdhci_auto_cmd12(host, cmd->mrq) &&
>> -                 (cmd->opcode != SD_IO_RW_EXTENDED))
>> -                     mode |= SDHCI_TRNS_AUTO_CMD12;
>> -             else if (cmd->mrq->sbc && (host->flags & SDHCI_AUTO_CMD23)) {
>> -                     mode |= SDHCI_TRNS_AUTO_CMD23;
>> -                     sdhci_writel(host, cmd->mrq->sbc->arg, SDHCI_ARGUMENT2);
>> -             }
>> +             sdhci_auto_cmd_select(host, cmd, &mode);
>>       }
>>
>>       if (data->flags & MMC_DATA_READ)
>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>> index daf8c1e..a8d5be5 100644
>> --- a/drivers/mmc/host/sdhci.h
>> +++ b/drivers/mmc/host/sdhci.h
>> @@ -43,6 +43,7 @@
>>  #define  SDHCI_TRNS_BLK_CNT_EN       0x02
>>  #define  SDHCI_TRNS_AUTO_CMD12       0x04
>>  #define  SDHCI_TRNS_AUTO_CMD23       0x08
>> +#define  SDHCI_TRNS_AUTO_SEL 0x0C
>>  #define  SDHCI_TRNS_READ     0x10
>>  #define  SDHCI_TRNS_MULTI    0x20
>>
>> @@ -186,6 +187,7 @@
>>  #define   SDHCI_CTRL_DRV_TYPE_D              0x0030
>>  #define  SDHCI_CTRL_EXEC_TUNING              0x0040
>>  #define  SDHCI_CTRL_TUNED_CLK                0x0080
>> +#define  SDHCI_CMD23_ENABLE          0x0800
>>  #define  SDHCI_CTRL_V4_MODE          0x1000
>>  #define  SDHCI_CTRL_64BIT_ADDR               0x2000
>>  #define  SDHCI_CTRL_PRESET_VAL_ENABLE        0x8000
>>
>