Re: [PATCH V5 07/10] mmc: sdhci: Add Auto CMD Auto Select support

From: Chunyan Zhang
Date: Fri Aug 24 2018 - 02:53:34 EST

On 23 August 2018 at 20:55, Adrian Hunter <adrian.hunter@xxxxxxxxx> 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@xxxxxxxxxx>
>> ---
>> 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
>>
>