phy: nuvoton: add NPCM7xx phy control driver

add BMC NPCM750 phy control driver

Signed-off-by: Jim Liu <JJLIU0@nuvoton.com>
diff --git a/drivers/phy/phy-npcm-usb.c b/drivers/phy/phy-npcm-usb.c
new file mode 100644
index 0000000..24eba66
--- /dev/null
+++ b/drivers/phy/phy-npcm-usb.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021 Nuvoton Technology Corp.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <generic-phy.h>
+#include <regmap.h>
+#include <reset.h>
+#include <syscon.h>
+#include <dm/device_compat.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+
+/* GCR Register Offsets */
+#define GCR_INTCR3	0x9C
+#define GCR_USB1PHYCTL	0x140
+#define GCR_USB2PHYCTL	0x144
+#define GCR_USB3PHYCTL	0x148
+
+/* USBnPHYCTL bit fields */
+#define PHYCTL_RS	BIT(28)
+
+#define USBPHY2SW	GENMASK(13, 12)
+#define USBPHY3SW	GENMASK(15, 14)
+
+#define USBPHY2SW_DEV9_PHY1	FIELD_PREP(USBPHY2SW, 0)
+#define USBPHY2SW_HOST1		FIELD_PREP(USBPHY2SW, 1)
+#define USBPHY2SW_DEV9_PHY2	FIELD_PREP(USBPHY2SW, 3)
+#define USBPHY3SW_DEV8_PHY1	FIELD_PREP(USBPHY3SW, 0)
+#define USBPHY3SW_HOST2		FIELD_PREP(USBPHY3SW, 1)
+#define USBPHY3SW_DEV8_PHY3	FIELD_PREP(USBPHY3SW, 3)
+
+enum controller_id {
+	UDC0_7,
+	UDC8,
+	UDC9,
+	USBH1,
+	USBH2,
+};
+
+enum phy_id {
+	PHY1 = 1,
+	PHY2,
+	PHY3,
+};
+
+/* Phy Switch Settings */
+#define USBDPHY1	((PHY1 << 8) | UDC0_7)	/* Connect UDC0~7 to PHY1 */
+#define USBD8PHY1	((PHY1 << 8) | UDC8)	/* Connect UDC8 to PHY1 */
+#define USBD9PHY1	((PHY1 << 8) | UDC9)	/* Connect UDC9 to PHY1 */
+#define USBD9PHY2	((PHY2 << 8) | UDC9)	/* Connect UDC9 to PHY2 */
+#define USBH1PHY2	((PHY2 << 8) | USBH1)	/* Connect USBH1 to PHY2 */
+#define USBD8PHY3	((PHY3 << 8) | UDC8)	/* Connect UDC8 to PHY3 */
+#define USBH2PHY3	((PHY3 << 8) | USBH2)	/* Connect USBH2 to PHY3 */
+
+struct npcm_usbphy {
+	struct regmap *syscon;
+	u8 id;
+	u16 phy_switch;	/* (phy_id << 8) | controller_id */
+};
+
+static int npcm_usb_phy_init(struct phy *phy)
+{
+	struct npcm_usbphy *priv = dev_get_priv(phy->dev);
+	struct reset_ctl reset;
+	int ret;
+
+	ret = reset_get_by_index(phy->dev, 0, &reset);
+	if (ret && ret != -ENOENT && ret != -ENOTSUPP) {
+		dev_err(phy->dev, "can't get phy reset ctrl (err %d)", ret);
+		return ret;
+	}
+
+	/* setup PHY switch */
+	switch (priv->phy_switch) {
+	case USBD8PHY1:
+		regmap_update_bits(priv->syscon, GCR_INTCR3, USBPHY3SW,
+				   USBPHY3SW_DEV8_PHY1);
+		break;
+	case USBD8PHY3:
+		regmap_update_bits(priv->syscon, GCR_INTCR3, USBPHY3SW,
+				   USBPHY3SW_DEV8_PHY3);
+		break;
+	case USBD9PHY1:
+		regmap_update_bits(priv->syscon, GCR_INTCR3, USBPHY2SW,
+				   USBPHY2SW_DEV9_PHY1);
+		break;
+	case USBD9PHY2:
+		regmap_update_bits(priv->syscon, GCR_INTCR3, USBPHY2SW,
+				   USBPHY2SW_DEV9_PHY2);
+		break;
+	case USBH1PHY2:
+		regmap_update_bits(priv->syscon, GCR_INTCR3, USBPHY2SW,
+				   USBPHY2SW_HOST1);
+		break;
+	case USBH2PHY3:
+		regmap_update_bits(priv->syscon, GCR_INTCR3, USBPHY3SW,
+				   USBPHY3SW_HOST2);
+		break;
+	default:
+		break;
+	}
+	/* reset phy */
+	if (reset_valid(&reset))
+		reset_assert(&reset);
+
+	/* Wait for PHY clocks to stablize for 50us or more */
+	udelay(100);
+
+	/* release phy from reset */
+	if (reset_valid(&reset))
+		reset_deassert(&reset);
+
+	/* PHY RS bit should be set after reset */
+	switch (priv->id) {
+	case PHY1:
+		regmap_update_bits(priv->syscon, GCR_USB1PHYCTL, PHYCTL_RS, PHYCTL_RS);
+		break;
+	case PHY2:
+		regmap_update_bits(priv->syscon, GCR_USB2PHYCTL, PHYCTL_RS, PHYCTL_RS);
+		break;
+	case PHY3:
+		regmap_update_bits(priv->syscon, GCR_USB3PHYCTL, PHYCTL_RS, PHYCTL_RS);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int npcm_usb_phy_exit(struct phy *phy)
+{
+	struct npcm_usbphy *priv = dev_get_priv(phy->dev);
+
+	/* set PHY switch to default state */
+	switch (priv->phy_switch) {
+	case USBD8PHY1:
+	case USBD8PHY3:
+		regmap_update_bits(priv->syscon, GCR_INTCR3, USBPHY3SW,
+				   USBPHY3SW_HOST2);
+		break;
+	case USBD9PHY1:
+	case USBD9PHY2:
+		regmap_update_bits(priv->syscon, GCR_INTCR3, USBPHY2SW,
+				   USBPHY2SW_HOST1);
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static int  npcm_usb_phy_xlate(struct phy *phy, struct ofnode_phandle_args *args)
+{
+	struct npcm_usbphy *priv = dev_get_priv(phy->dev);
+	u16 phy_switch;
+
+	if (args->args_count < 1 || args->args[0] > USBH2)
+		return -EINVAL;
+
+	phy_switch = (priv->id << 8) | args->args[0];
+	switch (phy_switch) {
+	case USBD9PHY1:
+	case USBH2PHY3:
+	case USBD8PHY3:
+		if (!IS_ENABLED(CONFIG_ARCH_NPCM8XX))
+			return -EINVAL;
+	case USBDPHY1:
+	case USBD8PHY1:
+	case USBD9PHY2:
+	case USBH1PHY2:
+		priv->phy_switch = phy_switch;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int npcm_usb_phy_probe(struct udevice *dev)
+{
+	struct npcm_usbphy *priv = dev_get_priv(dev);
+
+	priv->syscon = syscon_regmap_lookup_by_phandle(dev->parent, "syscon");
+	if (IS_ERR(priv->syscon)) {
+		dev_err(dev, "%s: unable to get syscon\n", __func__);
+		return PTR_ERR(priv->syscon);
+	}
+	priv->id = dev_read_u32_default(dev, "reg", -1);
+
+	return 0;
+}
+
+static const struct udevice_id npcm_phy_ids[] = {
+	{ .compatible = "nuvoton,npcm845-usb-phy",},
+	{ .compatible = "nuvoton,npcm750-usb-phy",},
+	{ }
+};
+
+static struct phy_ops npcm_phy_ops = {
+	.init = npcm_usb_phy_init,
+	.exit = npcm_usb_phy_exit,
+	.of_xlate = npcm_usb_phy_xlate,
+};
+
+U_BOOT_DRIVER(npcm_phy) = {
+	.name	= "npcm-usb-phy",
+	.id	= UCLASS_PHY,
+	.of_match = npcm_phy_ids,
+	.ops = &npcm_phy_ops,
+	.probe		= npcm_usb_phy_probe,
+	.priv_auto	= sizeof(struct npcm_usbphy),
+};