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Subject[PATCH V4 1/7] mmc: sdhci: add sd host v4 mode
Date
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@linaro.org>
---
drivers/mmc/host/sdhci.c | 28 ++++++++++++++++++++++++++++
drivers/mmc/host/sdhci.h | 5 +++++
2 files changed, 33 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 1c828e0..cab5350 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -123,6 +123,30 @@ 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);
+}
+
+/*
+ * Vendor's Host Controller which supports v4 mode can call
+ * this function to enable v4 mode before calling
+ * __sdhci_add_host().
+ */
+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;
@@ -224,6 +248,10 @@ static void sdhci_do_reset(struct sdhci_host *host, u8 mask)

/* Resetting the controller clears many */
host->preset_enabled = false;
+
+ if (host->v4_mode)
+ sdhci_do_enable_v4_mode(host);
+
}
}

diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 23966f8..519d939 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
@@ -565,6 +566,9 @@ struct sdhci_host {

u64 data_timeout;

+ /* Host Version 4 Enable */
+ bool v4_mode;
+
unsigned long private[0] ____cacheline_aligned;
};

@@ -747,5 +751,6 @@ 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);

#endif /* __SDHCI_HW_H */
--
2.7.4
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