[PATCH 2/4] mmc: dw_mmc: setup set_enhanced_strobe ops in driver

[Kaustabh Chakraborty]

At the end of HS400ES initialization by the core mmc driver,
mmc_set_enhanced_strobe() is called. This expects the host driver to
have an ops function for it.

The DW-MMC driver does not have it, thus the call fails with -ENOSUPP.
Add the ops function to allow control to be passed to the host side.

Since DW-MMC driver implementation depends on the platform, the above
ops function is made to pass its control to the implementation-specific
function available in the platform-specific driver.

Signed-off-by: Kaustabh Chakraborty <kauschluss at disroot.org>
---
 drivers/mmc/dw_mmc.c | 19 +++++++++++++++++++
 include/dwmmc.h      | 10 ++++++++++
 2 files changed, 29 insertions(+)

diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index d9c05b223d5..0a245d72881 100644
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -730,6 +730,19 @@ static int dwmci_init(struct mmc *mmc)
 	return 0;
 }
 
+#if CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT)
+static int dwmci_set_enhanced_strobe(struct udevice *dev)
+{
+	struct mmc *mmc = mmc_get_mmc_dev(dev);
+	struct dwmci_host *host = mmc->priv;
+
+	if (host && host->set_enhanced_strobe)
+		return host->set_enhanced_strobe(host);
+
+	return 0;
+}
+#endif
+
 #if CONFIG_IS_ENABLED(DM_MMC)
 int dwmci_probe(struct udevice *dev)
 {
@@ -741,6 +754,9 @@ int dwmci_probe(struct udevice *dev)
 const struct dm_mmc_ops dm_dwmci_ops = {
 	.send_cmd	= dwmci_send_cmd,
 	.set_ios	= dwmci_set_ios,
+#if CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT)
+	.set_enhanced_strobe = dwmci_set_enhanced_strobe,
+#endif
 };
 
 #else
@@ -748,6 +764,9 @@ static const struct mmc_ops dwmci_ops = {
 	.send_cmd	= dwmci_send_cmd,
 	.set_ios	= dwmci_set_ios,
 	.init		= dwmci_init,
+#if CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT)
+	.set_enhanced_strobe = dwmci_set_enhanced_strobe,
+#endif
 };
 #endif
 
diff --git a/include/dwmmc.h b/include/dwmmc.h
index 7e1a6646518..49488709a82 100644
--- a/include/dwmmc.h
+++ b/include/dwmmc.h
@@ -225,6 +225,16 @@ struct dwmci_host {
 	 * return that value too. Then DWMMC will put itself in bypass mode.
 	 */
 	unsigned int (*get_mmc_clk)(struct dwmci_host *host, uint freq);
+	/**
+	 * @set_enhanced_strobe: (Optional) Platform function to run on enabling
+	 * HS400ES strobe
+	 *
+	 * @host:	DWMMC host
+	 *
+	 * This is used to enable the enhanced strobe for the HS400ES MMC mode.
+	 * The caller invokes this at the end of the HS400ES frequency dance.
+	 */
+	unsigned int (*set_enhanced_strobe)(struct dwmci_host *host);
 
 #ifndef CONFIG_BLK
 	struct mmc_config cfg;

-- 
2.53.0