[PATCH v2 22/30] mci: imx-esdhc: select different pinctrl state depending on frequency

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Like done before for the card side, we need to adjust drive strength on
the host as well with higher data rates. For i.MX, this is done via
speed-specific pincontrol groups, so implement this binding.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 drivers/mci/imx-esdhc.c | 48 +++++++++++++++++++++++++++++++++++++++++
 drivers/mci/imx-esdhc.h |  3 +++
 2 files changed, 51 insertions(+)

diff --git a/drivers/mci/imx-esdhc.c b/drivers/mci/imx-esdhc.c
index 3871f85ea6d6..18a5750ed0ed 100644
--- a/drivers/mci/imx-esdhc.c
+++ b/drivers/mci/imx-esdhc.c
@@ -14,6 +14,7 @@
 #include <of.h>
 #include <malloc.h>
 #include <mci.h>
+#include <linux/pinctrl/consumer.h>
 #include <clock.h>
 #include <io.h>
 #include <linux/clk.h>
@@ -56,6 +57,9 @@
 #define ESDHC_TUNING_STEP_MASK		0x00070000
 #define ESDHC_TUNING_STEP_SHIFT		16
 
+/* pinctrl state */
+#define ESDHC_PINCTRL_STATE_100MHZ	"state_100mhz"
+#define ESDHC_PINCTRL_STATE_200MHZ	"state_200mhz"
 
 #define to_fsl_esdhc(mci)	container_of(mci, struct fsl_esdhc_host, mci)
 
@@ -133,6 +137,37 @@ static void set_sysctl(struct mci_host *mci, u32 clock, bool ddr)
 		   10 * MSECOND);
 }
 
+static int esdhc_change_pinstate(struct fsl_esdhc_host *host,
+				 unsigned int uhs)
+{
+	struct pinctrl_state *pinctrl;
+
+	dev_dbg(host->dev, "change pinctrl state for uhs %d\n", uhs);
+
+	if (IS_ERR(host->pinctrl) ||
+		IS_ERR(host->pins_100mhz) ||
+		IS_ERR(host->pins_200mhz))
+		return -EINVAL;
+
+	switch (uhs) {
+	case MMC_TIMING_UHS_SDR50:
+	case MMC_TIMING_UHS_DDR50:
+		pinctrl = host->pins_100mhz;
+		break;
+	case MMC_TIMING_UHS_SDR104:
+	case MMC_TIMING_MMC_HS200:
+	case MMC_TIMING_MMC_HS400:
+		pinctrl = host->pins_200mhz;
+		break;
+	default:
+		/* back to default state for other legacy timing */
+		return pinctrl_select_state_default(host->dev);
+	}
+
+	return pinctrl_select_state(host->pinctrl, pinctrl);
+}
+
+
 static void usdhc_set_timing(struct fsl_esdhc_host *host, enum mci_timing timing)
 {
 	u32 mixctrl;
@@ -159,6 +194,8 @@ static void usdhc_set_timing(struct fsl_esdhc_host *host, enum mci_timing timing
 		sdhci_write32(&host->sdhci, IMX_SDHCI_MIXCTRL, mixctrl);
 	}
 
+	esdhc_change_pinstate(host, timing);
+
 	host->sdhci.timing = timing;
 }
 
@@ -355,6 +392,13 @@ static void fsl_esdhc_probe_dt(struct device *dev, struct fsl_esdhc_host *host)
 		boarddata->tuning_start_tap = ESDHC_TUNING_START_TAP_DEFAULT;
 	if (of_property_read_u32(np, "fsl,delay-line", &boarddata->delay_line))
 		boarddata->delay_line = 0;
+
+	if (esdhc_is_usdhc(host) && !IS_ERR(host->pinctrl)) {
+		host->pins_100mhz = pinctrl_lookup_state(host->pinctrl,
+						ESDHC_PINCTRL_STATE_100MHZ);
+		host->pins_200mhz = pinctrl_lookup_state(host->pinctrl,
+						ESDHC_PINCTRL_STATE_200MHZ);
+	}
 }
 
 static int fsl_esdhc_probe(struct device *dev)
@@ -417,6 +461,10 @@ static int fsl_esdhc_probe(struct device *dev)
 
 	mci_of_parse(&host->mci);
 
+	host->pinctrl = pinctrl_get(dev);
+	if (IS_ERR(host->pinctrl))
+		dev_warn(host->dev, "could not get pinctrl\n");
+
 	fsl_esdhc_probe_dt(dev, host);
 
 	ret = mci_register(&host->mci);
diff --git a/drivers/mci/imx-esdhc.h b/drivers/mci/imx-esdhc.h
index 569986c1bf0e..e24d76d0c687 100644
--- a/drivers/mci/imx-esdhc.h
+++ b/drivers/mci/imx-esdhc.h
@@ -153,6 +153,9 @@ struct fsl_esdhc_host {
 	struct mci_host		mci;
 	struct clk		*clk;
 	struct device		*dev;
+	struct pinctrl		*pinctrl;
+	struct pinctrl_state	*pins_100mhz;
+	struct pinctrl_state	*pins_200mhz;
 	const struct esdhc_soc_data *socdata;
 	struct esdhc_platform_data boarddata;
 	u32		last_cmd;
-- 
2.39.5