phy: Add Amlogic Meson USB2 & USB3 Generic PHY drivers

The Amlogic Meson GXL and GXM (simple variant) embeds up to 3 USB2 PHYs
and an USB3 PHY. This patch adds drivers for these for the standard generic
PHY interface and supports the power-on/off calls and set the Host mode by
default.
They are based on the excellent work from Martin Blumenstingl merged in linux.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/drivers/phy/meson-gxl-usb3.c b/drivers/phy/meson-gxl-usb3.c
new file mode 100644
index 0000000..a385fbd
--- /dev/null
+++ b/drivers/phy/meson-gxl-usb3.c
@@ -0,0 +1,201 @@
+/*
+ * Meson GXL USB3 PHY driver
+ *
+ * Copyright (C) 2018 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+ * Copyright (C) 2018 BayLibre, SAS
+ * Author: Neil Armstrong <narmstron@baylibre.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <bitfield.h>
+#include <dm.h>
+#include <errno.h>
+#include <generic-phy.h>
+#include <regmap.h>
+#include <clk.h>
+
+#include <linux/bitops.h>
+#include <linux/compat.h>
+#include <linux/bitfield.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define USB_R0							0x00
+	#define USB_R0_P30_FSEL_MASK				GENMASK(5, 0)
+	#define USB_R0_P30_PHY_RESET				BIT(6)
+	#define USB_R0_P30_TEST_POWERDOWN_HSP			BIT(7)
+	#define USB_R0_P30_TEST_POWERDOWN_SSP			BIT(8)
+	#define USB_R0_P30_ACJT_LEVEL_MASK			GENMASK(13, 9)
+	#define USB_R0_P30_TX_BOOST_LEVEL_MASK			GENMASK(16, 14)
+	#define USB_R0_P30_LANE0_TX2RX_LOOPBACK			BIT(17)
+	#define USB_R0_P30_LANE0_EXT_PCLK_REQ			BIT(18)
+	#define USB_R0_P30_PCS_RX_LOS_MASK_VAL_MASK		GENMASK(28, 19)
+	#define USB_R0_U2D_SS_SCALEDOWN_MODE_MASK		GENMASK(30, 29)
+	#define USB_R0_U2D_ACT					BIT(31)
+
+#define USB_R1							0x04
+	#define USB_R1_U3H_BIGENDIAN_GS				BIT(0)
+	#define USB_R1_U3H_PME_ENABLE				BIT(1)
+	#define USB_R1_U3H_HUB_PORT_OVERCURRENT_MASK		GENMASK(6, 2)
+	#define USB_R1_U3H_HUB_PORT_PERM_ATTACH_MASK		GENMASK(11, 7)
+	#define USB_R1_U3H_HOST_U2_PORT_DISABLE_MASK		GENMASK(15, 12)
+	#define USB_R1_U3H_HOST_U3_PORT_DISABLE			BIT(16)
+	#define USB_R1_U3H_HOST_PORT_POWER_CONTROL_PRESENT	BIT(17)
+	#define USB_R1_U3H_HOST_MSI_ENABLE			BIT(18)
+	#define USB_R1_U3H_FLADJ_30MHZ_REG_MASK			GENMASK(24, 19)
+	#define USB_R1_P30_PCS_TX_SWING_FULL_MASK		GENMASK(31, 25)
+
+#define USB_R2							0x08
+	#define USB_R2_P30_CR_DATA_IN_MASK			GENMASK(15, 0)
+	#define USB_R2_P30_CR_READ				BIT(16)
+	#define USB_R2_P30_CR_WRITE				BIT(17)
+	#define USB_R2_P30_CR_CAP_ADDR				BIT(18)
+	#define USB_R2_P30_CR_CAP_DATA				BIT(19)
+	#define USB_R2_P30_PCS_TX_DEEMPH_3P5DB_MASK		GENMASK(25, 20)
+	#define USB_R2_P30_PCS_TX_DEEMPH_6DB_MASK		GENMASK(31, 26)
+
+#define USB_R3							0x0c
+	#define USB_R3_P30_SSC_ENABLE				BIT(0)
+	#define USB_R3_P30_SSC_RANGE_MASK			GENMASK(3, 1)
+	#define USB_R3_P30_SSC_REF_CLK_SEL_MASK			GENMASK(12, 4)
+	#define USB_R3_P30_REF_SSP_EN				BIT(13)
+	#define USB_R3_P30_LOS_BIAS_MASK			GENMASK(18, 16)
+	#define USB_R3_P30_LOS_LEVEL_MASK			GENMASK(23, 19)
+	#define USB_R3_P30_MPLL_MULTIPLIER_MASK			GENMASK(30, 24)
+
+#define USB_R4							0x10
+	#define USB_R4_P21_PORT_RESET_0				BIT(0)
+	#define USB_R4_P21_SLEEP_M0				BIT(1)
+	#define USB_R4_MEM_PD_MASK				GENMASK(3, 2)
+	#define USB_R4_P21_ONLY					BIT(4)
+
+#define USB_R5							0x14
+	#define USB_R5_ID_DIG_SYNC				BIT(0)
+	#define USB_R5_ID_DIG_REG				BIT(1)
+	#define USB_R5_ID_DIG_CFG_MASK				GENMASK(3, 2)
+	#define USB_R5_ID_DIG_EN_0				BIT(4)
+	#define USB_R5_ID_DIG_EN_1				BIT(5)
+	#define USB_R5_ID_DIG_CURR				BIT(6)
+	#define USB_R5_ID_DIG_IRQ				BIT(7)
+	#define USB_R5_ID_DIG_TH_MASK				GENMASK(15, 8)
+	#define USB_R5_ID_DIG_CNT_MASK				GENMASK(23, 16)
+
+/* read-only register */
+#define USB_R6							0x18
+	#define USB_R6_P30_CR_DATA_OUT_MASK			GENMASK(15, 0)
+	#define USB_R6_P30_CR_ACK				BIT(16)
+
+struct phy_meson_gxl_usb3_priv {
+	struct regmap		*regmap;
+#if CONFIG_IS_ENABLED(CLK)
+	struct clk		clk;
+#endif
+};
+
+static int
+phy_meson_gxl_usb3_set_host_mode(struct phy_meson_gxl_usb3_priv *priv)
+{
+	uint val;
+
+	regmap_read(priv->regmap, USB_R0, &val);
+	val &= ~USB_R0_U2D_ACT;
+	regmap_write(priv->regmap, USB_R0, val);
+
+	regmap_read(priv->regmap, USB_R4, &val);
+	val &= ~USB_R4_P21_SLEEP_M0;
+	regmap_write(priv->regmap, USB_R4, val);
+
+	return 0;
+}
+
+static int phy_meson_gxl_usb3_power_on(struct phy *phy)
+{
+	struct udevice *dev = phy->dev;
+	struct phy_meson_gxl_usb3_priv *priv = dev_get_priv(dev);
+	uint val;
+
+	regmap_read(priv->regmap, USB_R5, &val);
+	val |= USB_R5_ID_DIG_EN_0;
+	val |= USB_R5_ID_DIG_EN_1;
+	val &= ~USB_R5_ID_DIG_TH_MASK;
+	val |= FIELD_PREP(USB_R5_ID_DIG_TH_MASK, 0xff);
+	regmap_write(priv->regmap, USB_R5, val);
+
+	return phy_meson_gxl_usb3_set_host_mode(priv);
+}
+
+static int phy_meson_gxl_usb3_power_off(struct phy *phy)
+{
+	struct udevice *dev = phy->dev;
+	struct phy_meson_gxl_usb3_priv *priv = dev_get_priv(dev);
+	uint val;
+
+	regmap_read(priv->regmap, USB_R5, &val);
+	val &= ~USB_R5_ID_DIG_EN_0;
+	val &= ~USB_R5_ID_DIG_EN_1;
+	regmap_write(priv->regmap, USB_R5, val);
+
+	return 0;
+}
+
+static int phy_meson_gxl_usb3_init(struct phy *phy)
+{
+	struct udevice *dev = phy->dev;
+	struct phy_meson_gxl_usb3_priv *priv = dev_get_priv(dev);
+	uint val;
+
+	regmap_read(priv->regmap, USB_R1, &val);
+	val &= ~USB_R1_U3H_FLADJ_30MHZ_REG_MASK;
+	val |= FIELD_PREP(USB_R1_U3H_FLADJ_30MHZ_REG_MASK, 0x20);
+	regmap_write(priv->regmap, USB_R1, val);
+
+	return 0;
+}
+
+struct phy_ops meson_gxl_usb3_phy_ops = {
+	.init = phy_meson_gxl_usb3_init,
+	.power_on = phy_meson_gxl_usb3_power_on,
+	.power_off = phy_meson_gxl_usb3_power_off,
+};
+
+int meson_gxl_usb3_phy_probe(struct udevice *dev)
+{
+	struct phy_meson_gxl_usb3_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = regmap_init_mem(dev, &priv->regmap);
+	if (ret)
+		return ret;
+	
+#if CONFIG_IS_ENABLED(CLK)
+	ret = clk_get_by_index(dev, 0, &priv->clk);
+	if (ret < 0)
+		return ret;
+
+	ret = clk_enable(&priv->clk);
+	if (ret && ret != -ENOSYS && ret != -ENOTSUPP) {
+		pr_err("failed to enable PHY clock\n");
+		clk_free(&priv->clk);
+		return ret;
+	}
+#endif
+
+	return 0;
+}
+
+static const struct udevice_id meson_gxl_usb3_phy_ids[] = {
+	{ .compatible = "amlogic,meson-gxl-usb3-phy" },
+	{ }
+};
+
+U_BOOT_DRIVER(meson_gxl_usb3_phy) = {
+	.name = "meson_gxl_usb3_phy",
+	.id = UCLASS_PHY,
+	.of_match = meson_gxl_usb3_phy_ids,
+	.probe = meson_gxl_usb3_phy_probe,
+	.ops = &meson_gxl_usb3_phy_ops,
+	.priv_auto_alloc_size = sizeof(struct phy_meson_gxl_usb3_priv),
+};