phy: samsung: Add support for the Exynos5420 variant of the USB2 PHY

Exynos5420 differs a bit from Exynos5250 in USB2 PHY related registers in
the PMU region. Add a variant for the Exynos5420 case. Till now, USB2 PHY
worked only because the bootloader enabled the PHY, but then driver messed
USB 3.0 DRD related registers during the suspend/resume cycle.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201120085637.7299-2-m.szyprowski@samsung.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/samsung-phy.txt

@@ -47,6 +47,7 @@ Required properties:
 	- "samsung,exynos4210-usb2-phy"
 	- "samsung,exynos4x12-usb2-phy"
 	- "samsung,exynos5250-usb2-phy"
+	- "samsung,exynos5420-usb2-phy"
 	- "samsung,s5pv210-usb2-phy"
 - reg : a list of registers used by phy driver
 	- first and obligatory is the location of phy modules registers

drivers/phy/samsung/Kconfig

@@ -64,7 +64,12 @@ config PHY_EXYNOS4X12_USB2
 config PHY_EXYNOS5250_USB2
 	bool
 	depends on PHY_SAMSUNG_USB2
-	default SOC_EXYNOS5250 || SOC_EXYNOS5420
+	default SOC_EXYNOS5250
+
+config PHY_EXYNOS5420_USB2
+	bool
+	depends on PHY_SAMSUNG_USB2
+	default SOC_EXYNOS5420
 
 config PHY_S5PV210_USB2
 	bool "Support for S5PV210"

drivers/phy/samsung/phy-exynos5250-usb2.c

@@ -117,9 +117,9 @@
 
 /* Isolation, configured in the power management unit */
 #define EXYNOS_5250_USB_ISOL_OTG_OFFSET		0x704
-#define EXYNOS_5250_USB_ISOL_OTG		BIT(0)
 #define EXYNOS_5250_USB_ISOL_HOST_OFFSET	0x708
-#define EXYNOS_5250_USB_ISOL_HOST		BIT(0)
+#define EXYNOS_5420_USB_ISOL_HOST_OFFSET	0x70C
+#define EXYNOS_5250_USB_ISOL_ENABLE		BIT(0)
 
 /* Mode swtich register */
 #define EXYNOS_5250_MODE_SWITCH_OFFSET		0x230
@@ -132,7 +132,6 @@ enum exynos4x12_phy_id {
 	EXYNOS5250_HOST,
 	EXYNOS5250_HSIC0,
 	EXYNOS5250_HSIC1,
-	EXYNOS5250_NUM_PHYS,
 };
 
 /*
@@ -176,20 +175,19 @@ static void exynos5250_isol(struct samsung_usb2_phy_instance *inst, bool on)
 {
 	struct samsung_usb2_phy_driver *drv = inst->drv;
 	u32 offset;
-	u32 mask;
+	u32 mask = EXYNOS_5250_USB_ISOL_ENABLE;
 
-	switch (inst->cfg->id) {
-	case EXYNOS5250_DEVICE:
+	if (drv->cfg == &exynos5250_usb2_phy_config &&
+	    inst->cfg->id == EXYNOS5250_DEVICE)
 		offset = EXYNOS_5250_USB_ISOL_OTG_OFFSET;
-		mask = EXYNOS_5250_USB_ISOL_OTG;
-		break;
-	case EXYNOS5250_HOST:
+	else if (drv->cfg == &exynos5250_usb2_phy_config &&
+		 inst->cfg->id == EXYNOS5250_HOST)
 		offset = EXYNOS_5250_USB_ISOL_HOST_OFFSET;
-		mask = EXYNOS_5250_USB_ISOL_HOST;
-		break;
-	default:
+	else if (drv->cfg == &exynos5420_usb2_phy_config &&
+		 inst->cfg->id == EXYNOS5250_HOST)
+		offset = EXYNOS_5420_USB_ISOL_HOST_OFFSET;
+	else
 		return;
-	}
 
 	regmap_update_bits(drv->reg_pmu, offset, mask, on ? 0 : mask);
 }
@@ -390,9 +388,31 @@ static const struct samsung_usb2_common_phy exynos5250_phys[] = {
 	},
 };
 
+static const struct samsung_usb2_common_phy exynos5420_phys[] = {
+	{
+		.label		= "host",
+		.id		= EXYNOS5250_HOST,
+		.power_on	= exynos5250_power_on,
+		.power_off	= exynos5250_power_off,
+	},
+	{
+		.label		= "hsic",
+		.id		= EXYNOS5250_HSIC0,
+		.power_on	= exynos5250_power_on,
+		.power_off	= exynos5250_power_off,
+	},
+};
+
 const struct samsung_usb2_phy_config exynos5250_usb2_phy_config = {
 	.has_mode_switch	= 1,
-	.num_phys		= EXYNOS5250_NUM_PHYS,
+	.num_phys		= ARRAY_SIZE(exynos5250_phys),
 	.phys			= exynos5250_phys,
 	.rate_to_clk		= exynos5250_rate_to_clk,
 };
+
+const struct samsung_usb2_phy_config exynos5420_usb2_phy_config = {
+	.has_mode_switch	= 1,
+	.num_phys		= ARRAY_SIZE(exynos5420_phys),
+	.phys			= exynos5420_phys,
+	.rate_to_clk		= exynos5250_rate_to_clk,
+};

drivers/phy/samsung/phy-samsung-usb2.c

@@ -128,6 +128,12 @@ static const struct of_device_id samsung_usb2_phy_of_match[] = {
 		.data = &exynos5250_usb2_phy_config,
 	},
 #endif
+#ifdef CONFIG_PHY_EXYNOS5420_USB2
+	{
+		.compatible = "samsung,exynos5420-usb2-phy",
+		.data = &exynos5420_usb2_phy_config,
+	},
+#endif
 #ifdef CONFIG_PHY_S5PV210_USB2
 	{
 		.compatible = "samsung,s5pv210-usb2-phy",

drivers/phy/samsung/phy-samsung-usb2.h

@@ -66,5 +66,6 @@ extern const struct samsung_usb2_phy_config exynos3250_usb2_phy_config;
 extern const struct samsung_usb2_phy_config exynos4210_usb2_phy_config;
 extern const struct samsung_usb2_phy_config exynos4x12_usb2_phy_config;
 extern const struct samsung_usb2_phy_config exynos5250_usb2_phy_config;
+extern const struct samsung_usb2_phy_config exynos5420_usb2_phy_config;
 extern const struct samsung_usb2_phy_config s5pv210_usb2_phy_config;
 #endif