usb: chipidea: msm: Mux over secondary phy at the right time

We need to pick the correct phy at runtime based on how the SoC
has been wired onto the board. If the secondary phy is used, take
it out of reset and mux over to it by writing into the TCSR
register. Make sure to do this on reset too, because this
register is reset to the default value (primary phy) after the
RESET bit is set in USBCMD.
Acked-by: Peter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>

drivers/usb/chipidea/ci_hdrc_msm.c

@@ -8,29 +8,44 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
-#include <linux/usb/gadget.h>
 #include <linux/usb/chipidea.h>
 #include <linux/clk.h>
 #include <linux/reset.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/io.h>
 
 #include "ci.h"
 
 #define HS_PHY_AHB_MODE			0x0098
 
+/* Vendor base starts at 0x200 beyond CI base */
+#define HS_PHY_SEC_CTRL			0x0078
+#define HS_PHY_DIG_CLAMP_N		BIT(16)
+
 struct ci_hdrc_msm {
 	struct platform_device *ci;
 	struct clk *core_clk;
 	struct clk *iface_clk;
 	struct clk *fs_clk;
+	bool secondary_phy;
+	void __iomem *base;
 };
 
 static void ci_hdrc_msm_notify_event(struct ci_hdrc *ci, unsigned event)
 {
-	struct device *dev = ci->gadget.dev.parent;
+	struct device *dev = ci->dev->parent;
+	struct ci_hdrc_msm *msm_ci = dev_get_drvdata(dev);
 
 	switch (event) {
 	case CI_HDRC_CONTROLLER_RESET_EVENT:
 		dev_dbg(dev, "CI_HDRC_CONTROLLER_RESET_EVENT received\n");
+		if (msm_ci->secondary_phy) {
+			u32 val = readl_relaxed(msm_ci->base + HS_PHY_SEC_CTRL);
+			val |= HS_PHY_DIG_CLAMP_N;
+			writel_relaxed(val, msm_ci->base + HS_PHY_SEC_CTRL);
+		}
+
 		/* use AHB transactor, allow posted data writes */
 		hw_write_id_reg(ci, HS_PHY_AHB_MODE, 0xffffffff, 0x8);
 		usb_phy_init(ci->usb_phy);
@@ -59,6 +74,39 @@ static struct ci_hdrc_platform_data ci_hdrc_msm_platdata = {
 	.notify_event		= ci_hdrc_msm_notify_event,
 };
 
+static int ci_hdrc_msm_mux_phy(struct ci_hdrc_msm *ci,
+			       struct platform_device *pdev)
+{
+	struct regmap *regmap;
+	struct device *dev = &pdev->dev;
+	struct of_phandle_args args;
+	u32 val;
+	int ret;
+
+	ret = of_parse_phandle_with_fixed_args(dev->of_node, "phy-select", 2, 0,
+					       &args);
+	if (ret)
+		return 0;
+
+	regmap = syscon_node_to_regmap(args.np);
+	of_node_put(args.np);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	ret = regmap_write(regmap, args.args[0], args.args[1]);
+	if (ret)
+		return ret;
+
+	ci->secondary_phy = !!args.args[1];
+	if (ci->secondary_phy) {
+		val = readl_relaxed(ci->base + HS_PHY_SEC_CTRL);
+		val |= HS_PHY_DIG_CLAMP_N;
+		writel_relaxed(val, ci->base + HS_PHY_SEC_CTRL);
+	}
+
+	return 0;
+}
+
 static int ci_hdrc_msm_probe(struct platform_device *pdev)
 {
 	struct ci_hdrc_msm *ci;
@@ -66,6 +114,7 @@ static int ci_hdrc_msm_probe(struct platform_device *pdev)
 	struct usb_phy *phy;
 	struct clk *clk;
 	struct reset_control *reset;
+	struct resource *res;
 	int ret;
 
 	dev_dbg(&pdev->dev, "ci_hdrc_msm_probe\n");
@@ -105,6 +154,11 @@ static int ci_hdrc_msm_probe(struct platform_device *pdev)
 		ci->fs_clk = NULL;
 	}
 
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	ci->base = devm_ioremap_resource(&pdev->dev, res);
+	if (!ci->base)
+		return -ENOMEM;
+
 	ret = clk_prepare_enable(ci->fs_clk);
 	if (ret)
 		return ret;
@@ -123,6 +177,10 @@ static int ci_hdrc_msm_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_iface;
 
+	ret = ci_hdrc_msm_mux_phy(ci, pdev);
+	if (ret)
+		goto err_mux;
+
 	plat_ci = ci_hdrc_add_device(&pdev->dev,
 				pdev->resource, pdev->num_resources,
 				&ci_hdrc_msm_platdata);