phy: amlogic: meson8b-usb2: Use a MMIO regmap

Using a MMIO regmap and switch to regmap_update_bits() to simplify the
code in the driver. Also switch to devm_platform_ioremap_resource()
instead of open-coding it. No functional changes intended.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Thomas Graichen <thomas.graichen@gmail.com>
Link: https://lore.kernel.org/r/20200512222424.549351-4-martin.blumenstingl@googlemail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/amlogic/Kconfig

@@ -9,6 +9,7 @@ config PHY_MESON8B_USB2
 	depends on USB_SUPPORT
 	select USB_COMMON
 	select GENERIC_PHY
+	select REGMAP_MMIO
 	help
 	  Enable this to support the Meson USB2 PHYs found in Meson8,
 	  Meson8b and GXBB SoCs.

drivers/phy/amlogic/phy-meson8b-usb2.c

@@ -10,6 +10,7 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
+#include <linux/regmap.h>
 #include <linux/reset.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
@@ -105,34 +106,24 @@
 #define ACA_ENABLE_COMPLETE_TIME			50
 
 struct phy_meson8b_usb2_priv {
-	void __iomem		*regs;
+	struct regmap		*regmap;
 	enum usb_dr_mode	dr_mode;
 	struct clk		*clk_usb_general;
 	struct clk		*clk_usb;
 	struct reset_control	*reset;
 };
 
-static u32 phy_meson8b_usb2_read(struct phy_meson8b_usb2_priv *phy_priv,
-				 u32 reg)
-{
-	return readl(phy_priv->regs + reg);
-}
-
-static void phy_meson8b_usb2_mask_bits(struct phy_meson8b_usb2_priv *phy_priv,
-				       u32 reg, u32 mask, u32 value)
-{
-	u32 data;
-
-	data = phy_meson8b_usb2_read(phy_priv, reg);
-	data &= ~mask;
-	data |= (value & mask);
-
-	writel(data, phy_priv->regs + reg);
-}
+static const struct regmap_config phy_meson8b_usb2_regmap_conf = {
+	.reg_bits = 8,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = REG_TUNE,
+};
 
 static int phy_meson8b_usb2_power_on(struct phy *phy)
 {
 	struct phy_meson8b_usb2_priv *priv = phy_get_drvdata(phy);
+	u32 reg;
 	int ret;
 
 	if (!IS_ERR_OR_NULL(priv->reset)) {
@@ -156,34 +147,34 @@ static int phy_meson8b_usb2_power_on(struct phy *phy)
 		return ret;
 	}
 
-	phy_meson8b_usb2_mask_bits(priv, REG_CONFIG, REG_CONFIG_CLK_32k_ALTSEL,
+	regmap_update_bits(priv->regmap, REG_CONFIG, REG_CONFIG_CLK_32k_ALTSEL,
 			   REG_CONFIG_CLK_32k_ALTSEL);
 
-	phy_meson8b_usb2_mask_bits(priv, REG_CTRL, REG_CTRL_REF_CLK_SEL_MASK,
+	regmap_update_bits(priv->regmap, REG_CTRL, REG_CTRL_REF_CLK_SEL_MASK,
 			   0x2 << REG_CTRL_REF_CLK_SEL_SHIFT);
 
-	phy_meson8b_usb2_mask_bits(priv, REG_CTRL, REG_CTRL_FSEL_MASK,
+	regmap_update_bits(priv->regmap, REG_CTRL, REG_CTRL_FSEL_MASK,
 			   0x5 << REG_CTRL_FSEL_SHIFT);
 
 	/* reset the PHY */
-	phy_meson8b_usb2_mask_bits(priv, REG_CTRL, REG_CTRL_POWER_ON_RESET,
+	regmap_update_bits(priv->regmap, REG_CTRL, REG_CTRL_POWER_ON_RESET,
 			   REG_CTRL_POWER_ON_RESET);
 	udelay(RESET_COMPLETE_TIME);
-	phy_meson8b_usb2_mask_bits(priv, REG_CTRL, REG_CTRL_POWER_ON_RESET, 0);
+	regmap_update_bits(priv->regmap, REG_CTRL, REG_CTRL_POWER_ON_RESET, 0);
 	udelay(RESET_COMPLETE_TIME);
 
-	phy_meson8b_usb2_mask_bits(priv, REG_CTRL, REG_CTRL_SOF_TOGGLE_OUT,
+	regmap_update_bits(priv->regmap, REG_CTRL, REG_CTRL_SOF_TOGGLE_OUT,
 			   REG_CTRL_SOF_TOGGLE_OUT);
 
 	if (priv->dr_mode == USB_DR_MODE_HOST) {
-		phy_meson8b_usb2_mask_bits(priv, REG_ADP_BC,
+		regmap_update_bits(priv->regmap, REG_ADP_BC,
 				   REG_ADP_BC_ACA_ENABLE,
 				   REG_ADP_BC_ACA_ENABLE);
 
 		udelay(ACA_ENABLE_COMPLETE_TIME);
 
-		if (phy_meson8b_usb2_read(priv, REG_ADP_BC) &
-			REG_ADP_BC_ACA_PIN_FLOAT) {
+		regmap_read(priv->regmap, REG_ADP_BC, &reg);
+		if (reg & REG_ADP_BC_ACA_PIN_FLOAT) {
 			dev_warn(&phy->dev, "USB ID detect failed!\n");
 			clk_disable_unprepare(priv->clk_usb);
 			clk_disable_unprepare(priv->clk_usb_general);
@@ -213,18 +204,22 @@ static const struct phy_ops phy_meson8b_usb2_ops = {
 static int phy_meson8b_usb2_probe(struct platform_device *pdev)
 {
 	struct phy_meson8b_usb2_priv *priv;
-	struct resource *res;
 	struct phy *phy;
 	struct phy_provider *phy_provider;
+	void __iomem *base;
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	priv->regs = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(priv->regs))
-		return PTR_ERR(priv->regs);
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+					     &phy_meson8b_usb2_regmap_conf);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
 
 	priv->clk_usb_general = devm_clk_get(&pdev->dev, "usb_general");
 	if (IS_ERR(priv->clk_usb_general))