[PATCH V8 2/9] mmc: sdhci: Add sd host v4 mode

From: Chunyan Zhang
Date: Thu Aug 30 2018 - 04:22:09 EST


For SD host controller version 4.00 or later ones, there're two
modes of implementation - Version 3.00 compatible mode or
Version 4 mode. This patch introduced an interface to enable
v4 mode.

Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 29 +++++++++++++++++++++++++++++
drivers/mmc/host/sdhci.h | 3 +++
2 files changed, 32 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 01bf88c..0c61105 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -123,6 +123,29 @@ EXPORT_SYMBOL_GPL(sdhci_dumpregs);
* *
\*****************************************************************************/

+static void sdhci_do_enable_v4_mode(struct sdhci_host *host)
+{
+ u16 ctrl2;
+
+ ctrl2 = sdhci_readb(host, SDHCI_HOST_CONTROL2);
+ if (ctrl2 & SDHCI_CTRL_V4_MODE)
+ return;
+
+ ctrl2 |= SDHCI_CTRL_V4_MODE;
+ sdhci_writeb(host, ctrl2, SDHCI_HOST_CONTROL);
+}
+
+/*
+ * This can be called before sdhci_add_host() by Vendor's host controller
+ * driver to enable v4 mode if supported.
+ */
+void sdhci_enable_v4_mode(struct sdhci_host *host)
+{
+ host->v4_mode = true;
+ sdhci_do_enable_v4_mode(host);
+}
+EXPORT_SYMBOL_GPL(sdhci_enable_v4_mode);
+
static inline bool sdhci_data_line_cmd(struct mmc_command *cmd)
{
return cmd->data || cmd->flags & MMC_RSP_BUSY;
@@ -252,6 +275,9 @@ static void sdhci_init(struct sdhci_host *host, int soft)
else
sdhci_do_reset(host, SDHCI_RESET_ALL);

+ if (host->v4_mode)
+ sdhci_do_enable_v4_mode(host);
+
sdhci_set_default_irqs(host);

host->cqe_on = false;
@@ -3378,6 +3404,9 @@ void __sdhci_read_caps(struct sdhci_host *host, u16 *ver, u32 *caps, u32 *caps1)

sdhci_do_reset(host, SDHCI_RESET_ALL);

+ if (host->v4_mode)
+ sdhci_do_enable_v4_mode(host);
+
of_property_read_u64(mmc_dev(host->mmc)->of_node,
"sdhci-caps-mask", &dt_caps_mask);
of_property_read_u64(mmc_dev(host->mmc)->of_node,
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index dbd48a8..61611e3 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -184,6 +184,7 @@
#define SDHCI_CTRL_DRV_TYPE_D 0x0030
#define SDHCI_CTRL_EXEC_TUNING 0x0040
#define SDHCI_CTRL_TUNED_CLK 0x0080
+#define SDHCI_CTRL_V4_MODE 0x1000
#define SDHCI_CTRL_PRESET_VAL_ENABLE 0x8000

#define SDHCI_CAPABILITIES 0x40
@@ -504,6 +505,7 @@ struct sdhci_host {
bool preset_enabled; /* Preset is enabled */
bool pending_reset; /* Cmd/data reset is pending */
bool irq_wake_enabled; /* IRQ wakeup is enabled */
+ bool v4_mode; /* Host Version 4 Enable */

struct mmc_request *mrqs_done[SDHCI_MAX_MRQS]; /* Requests done */
struct mmc_command *cmd; /* Current command */
@@ -752,6 +754,7 @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error,
int *data_error);

void sdhci_dumpregs(struct sdhci_host *host);
+void sdhci_enable_v4_mode(struct sdhci_host *host);

void sdhci_start_tuning(struct sdhci_host *host);
void sdhci_end_tuning(struct sdhci_host *host);
--
2.7.4