[PATCH V4 5/7] mmc: sdhci: add Auto CMD Auto Select support

From: Chunyan Zhang
Date: Mon Jul 23 2018 - 06:09:34 EST


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 | 61 +++++++++++++++++++++++++++++++++++++++---------
drivers/mmc/host/sdhci.h | 2 ++
2 files changed, 52 insertions(+), 11 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 5acea3d..5c60590 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -311,6 +311,23 @@ 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)) {
+ 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;
@@ -329,6 +346,8 @@ static void sdhci_init(struct sdhci_host *host, int soft)
host->clock = 0;
mmc->ops->set_ios(mmc, &mmc->ios);
}
+
+ sdhci_enable_cmd23(host);
}

static void sdhci_reinit(struct sdhci_host *host)
@@ -1093,6 +1112,36 @@ 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;
+ 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)
{
@@ -1119,17 +1168,7 @@ 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 81aae07..a8f4ec2 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -42,6 +42,7 @@
#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

@@ -185,6 +186,7 @@
#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
--
2.7.4