[PATCH 4/7] phy: meson: add USB2 PHY support for Meson8b and GXBB

[Martin Blumenstingl <martin.blumenstingl-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>]

This is a new driver for the USB PHY found in Meson8b and GXBB SoCs.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
Signed-off-by: Jerome Brunet <jbrunet-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
---
 drivers/phy/Kconfig          |  11 ++
 drivers/phy/Makefile         |   1 +
 drivers/phy/phy-meson-usb2.c | 299 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 311 insertions(+)
 create mode 100644 drivers/phy/phy-meson-usb2.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 19bff3a..6ad87ec 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -453,4 +453,15 @@ config PHY_NS2_PCIE
 	help
 	  Enable this to support the Broadcom Northstar2 PCIe PHY.
 	  If unsure, say N.
+
+config PHY_MESON_USB2
+	tristate "Meson USB2 PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	help
+	  Enable this to support the Meson USB2 PHYs found in Meson8b
+	  and GXBB SoCs.
+	  If unsure, say N.
+
 endmenu
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 90ae198..dd507ac 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -56,3 +56,4 @@ obj-$(CONFIG_PHY_PISTACHIO_USB)		+= phy-pistachio-usb.o
 obj-$(CONFIG_PHY_CYGNUS_PCIE)		+= phy-bcm-cygnus-pcie.o
 obj-$(CONFIG_ARCH_TEGRA) += tegra/
 obj-$(CONFIG_PHY_NS2_PCIE)		+= phy-bcm-ns2-pcie.o
+obj-$(CONFIG_PHY_MESON_USB2)		+= phy-meson-usb2.o
diff --git a/drivers/phy/phy-meson-usb2.c b/drivers/phy/phy-meson-usb2.c
new file mode 100644
index 0000000..8cda138
--- /dev/null
+++ b/drivers/phy/phy-meson-usb2.c
@@ -0,0 +1,299 @@
+/*
+ * Meson USB2 PHY driver
+ *
+ * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/reset.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/usb/of.h>
+
+#define REG_CONFIG					0x00
+	#define REG_CONFIG_CLK_EN			BIT(0)
+	#define REG_CONFIG_CLK_SEL_MASK			GENMASK(3, 1)
+	#define REG_CONFIG_CLK_DIV_MASK			GENMASK(10, 4)
+	#define REG_CONFIG_CLK_32k_ALTSEL		BIT(15)
+	#define REG_CONFIG_TEST_TRIG			BIT(31)
+
+#define REG_CTRL					0x04
+	#define REG_CTRL_SOFT_PRST			BIT(0)
+	#define REG_CTRL_SOFT_HRESET			BIT(1)
+	#define REG_CTRL_SS_SCALEDOWN_MODE_MASK		GENMASK(3, 2)
+	#define REG_CTRL_CLK_DET_RST			BIT(4)
+	#define REG_CTRL_INTR_SEL			BIT(5)
+	#define REG_CTRL_CLK_DETECTED			BIT(8)
+	#define REG_CTRL_SOF_SENT_RCVD_TGL		BIT(9)
+	#define REG_CTRL_SOF_TOGGLE_OUT			BIT(10)
+	#define REG_CTRL_POWER_ON_RESET			BIT(15)
+	#define REG_CTRL_SLEEPM				BIT(16)
+	#define REG_CTRL_TX_BITSTUFF_ENN_H		BIT(17)
+	#define REG_CTRL_TX_BITSTUFF_ENN		BIT(18)
+	#define REG_CTRL_COMMON_ON			BIT(19)
+	#define REG_CTRL_REF_CLK_SEL_MASK		GENMASK(21, 20)
+	#define REG_CTRL_REF_CLK_SEL_SHIFT		20
+	#define REG_CTRL_FSEL_MASK			GENMASK(24, 22)
+	#define REG_CTRL_FSEL_SHIFT			22
+	#define REG_CTRL_PORT_RESET			BIT(25)
+	#define REG_CTRL_THREAD_ID_MASK			GENMASK(31, 26)
+
+#define REG_ENDP_INTR					0x08
+
+/* bits [31:26], [24:21] and [15:3] seem to be read-only */
+#define REG_ADP_BC					0x0c
+	#define REG_ADP_BC_VBUS_VLD_EXT_SEL		BIT(0)
+	#define REG_ADP_BC_VBUS_VLD_EXT			BIT(1)
+	#define REG_ADP_BC_OTG_DISABLE			BIT(2)
+	#define REG_ADP_BC_ID_PULLUP			BIT(3)
+	#define REG_ADP_BC_DRV_VBUS			BIT(4)
+	#define REG_ADP_BC_ADP_PRB_EN			BIT(5)
+	#define REG_ADP_BC_ADP_DISCHARGE		BIT(6)
+	#define REG_ADP_BC_ADP_CHARGE			BIT(7)
+	#define REG_ADP_BC_SESS_END			BIT(8)
+	#define REG_ADP_BC_DEVICE_SESS_VLD		BIT(9)
+	#define REG_ADP_BC_B_VALID			BIT(10)
+	#define REG_ADP_BC_A_VALID			BIT(11)
+	#define REG_ADP_BC_ID_DIG			BIT(12)
+	#define REG_ADP_BC_VBUS_VALID			BIT(13)
+	#define REG_ADP_BC_ADP_PROBE			BIT(14)
+	#define REG_ADP_BC_ADP_SENSE			BIT(15)
+	#define REG_ADP_BC_ACA_ENABLE			BIT(16)
+	#define REG_ADP_BC_DCD_ENABLE			BIT(17)
+	#define REG_ADP_BC_VDAT_DET_EN_B		BIT(18)
+	#define REG_ADP_BC_VDAT_SRC_EN_B		BIT(19)
+	#define REG_ADP_BC_CHARGE_SEL			BIT(20)
+	#define REG_ADP_BC_CHARGE_DETECT		BIT(21)
+	#define REG_ADP_BC_ACA_PIN_RANGE_C		BIT(22)
+	#define REG_ADP_BC_ACA_PIN_RANGE_B		BIT(23)
+	#define REG_ADP_BC_ACA_PIN_RANGE_A		BIT(24)
+	#define REG_ADP_BC_ACA_PIN_GND			BIT(25)
+	#define REG_ADP_BC_ACA_PIN_FLOAT		BIT(26)
+
+#define REG_DBG_UART					0x14
+
+#define REG_TEST					0x18
+	#define REG_TEST_DATA_IN_MASK			GENMASK(3, 0)
+	#define REG_TEST_EN_MASK			GENMASK(7, 4)
+	#define REG_TEST_ADDR_MASK			GENMASK(11, 8)
+	#define REG_TEST_DATA_OUT_SEL			BIT(12)
+	#define REG_TEST_CLK				BIT(13)
+	#define REG_TEST_VA_TEST_EN_B_MASK		GENMASK(15, 14)
+	#define REG_TEST_DATA_OUT_MASK			GENMASK(19, 16)
+	#define REG_TEST_DISABLE_ID_PULLUP		BIT(20)
+
+#define REG_TUNE					0x1c
+	#define REG_TUNE_TX_RES_TUNE_MASK		GENMASK(1, 0)
+	#define REG_TUNE_TX_HSXV_TUNE_MASK		GENMASK(3, 2)
+	#define REG_TUNE_TX_VREF_TUNE_MASK		GENMASK(7, 4)
+	#define REG_TUNE_TX_RISE_TUNE_MASK		GENMASK(9, 8)
+	#define REG_TUNE_TX_PREEMP_PULSE_TUNE		BIT(10)
+	#define REG_TUNE_TX_PREEMP_AMP_TUNE_MASK	GENMASK(12, 11)
+	#define REG_TUNE_TX_FSLS_TUNE_MASK		GENMASK(16, 13)
+	#define REG_TUNE_SQRX_TUNE_MASK			GENMASK(19, 17)
+	#define REG_TUNE_OTG_TUNE			GENMASK(22, 20)
+	#define REG_TUNE_COMP_DIS_TUNE			GENMASK(25, 23)
+	#define REG_TUNE_HOST_DM_PULLDOWN		BIT(26)
+	#define REG_TUNE_HOST_DP_PULLDOWN		BIT(27)
+
+#define RESET_COMPLETE_TIME				500
+#define ACA_ENABLE_COMPLETE_TIME			50
+
+/*
+ * The PHYs are sharing a common reset line -> we are only allowed to reset
+ * once for all PHYs.
+ */
+static int usb_reset_refcnt;
+
+struct phy_meson_usb2_priv {
+	void __iomem		*regs;
+	enum usb_dr_mode	dr_mode;
+	struct reset_control	*reset_usb_otg;
+	struct clk		*clk_usb_general;
+	struct clk		*clk_usb;
+};
+
+static u32 phy_meson_usb2_read(struct phy_meson_usb2_priv *phy_priv, u32 reg)
+{
+	return readl(phy_priv->regs + reg);
+}
+
+static void phy_meson_usb2_mask_bits(struct phy_meson_usb2_priv *phy_priv,
+				     u32 reg, u32 mask, u32 value)
+{
+	u32 data;
+
+	data = phy_meson_usb2_read(phy_priv, reg);
+	data &= ~mask;
+	data |= (value & mask);
+
+	writel(data, phy_priv->regs + reg);
+}
+
+static int phy_meson_usb2_power_on(struct phy *phy)
+{
+	struct phy_meson_usb2_priv *priv = phy_get_drvdata(phy);
+	int ret;
+
+	ret = clk_prepare_enable(priv->clk_usb_general);
+	if (ret) {
+		dev_err(&phy->dev, "Failed to enable USB general clock\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(priv->clk_usb);
+	if (ret) {
+		dev_err(&phy->dev, "Failed to enable USB DDR clock\n");
+		return ret;
+	}
+
+	phy_meson_usb2_mask_bits(priv, REG_CONFIG, REG_CONFIG_CLK_32k_ALTSEL,
+				 REG_CONFIG_CLK_32k_ALTSEL);
+
+	phy_meson_usb2_mask_bits(priv, REG_CTRL, REG_CTRL_REF_CLK_SEL_MASK,
+				 0x2 << REG_CTRL_REF_CLK_SEL_SHIFT);
+
+	phy_meson_usb2_mask_bits(priv, REG_CTRL, REG_CTRL_FSEL_MASK,
+				 0x5 << REG_CTRL_FSEL_SHIFT);
+
+	/* reset the PHY */
+	phy_meson_usb2_mask_bits(priv, REG_CTRL, REG_CTRL_POWER_ON_RESET,
+				 REG_CTRL_POWER_ON_RESET);
+	udelay(RESET_COMPLETE_TIME);
+	phy_meson_usb2_mask_bits(priv, REG_CTRL, REG_CTRL_POWER_ON_RESET, 0);
+	udelay(RESET_COMPLETE_TIME);
+
+	phy_meson_usb2_mask_bits(priv, REG_CTRL, REG_CTRL_SOF_TOGGLE_OUT,
+				 REG_CTRL_SOF_TOGGLE_OUT);
+
+	if (priv->dr_mode == USB_DR_MODE_HOST) {
+		phy_meson_usb2_mask_bits(priv, REG_ADP_BC,
+					 REG_ADP_BC_ACA_ENABLE,
+					 REG_ADP_BC_ACA_ENABLE);
+
+		udelay(ACA_ENABLE_COMPLETE_TIME);
+
+		if (phy_meson_usb2_read(priv, REG_ADP_BC) &
+			REG_ADP_BC_ACA_PIN_FLOAT) {
+			dev_warn(&phy->dev, "USB ID detect failed!\n");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int phy_meson_usb2_power_off(struct phy *phy)
+{
+	struct phy_meson_usb2_priv *priv = phy_get_drvdata(phy);
+
+	clk_disable_unprepare(priv->clk_usb);
+	clk_disable_unprepare(priv->clk_usb_general);
+
+	return 0;
+}
+
+static const struct phy_ops phy_meson_usb2_ops = {
+	.power_on	= phy_meson_usb2_power_on,
+	.power_off	= phy_meson_usb2_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static int phy_meson_usb2_probe(struct platform_device *pdev)
+{
+	struct phy_meson_usb2_priv *priv;
+	struct resource *res;
+	struct phy *phy;
+	struct phy_provider *phy_provider;
+	int ret;
+
+	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);
+
+	priv->clk_usb_general = devm_clk_get(&pdev->dev, "usb_general");
+	if (IS_ERR(priv->clk_usb_general))
+		return PTR_ERR(priv->clk_usb_general);
+
+	priv->clk_usb = devm_clk_get(&pdev->dev, "usb");
+	if (IS_ERR(priv->clk_usb))
+		return PTR_ERR(priv->clk_usb);
+
+	priv->dr_mode = of_usb_get_dr_mode_by_phy(pdev->dev.of_node, -1);
+	if (priv->dr_mode == USB_DR_MODE_UNKNOWN) {
+		dev_err(&pdev->dev,
+			"missing dual role configuration of the controller\n");
+		return -EINVAL;
+	}
+
+	phy = devm_phy_create(&pdev->dev, NULL, &phy_meson_usb2_ops);
+	if (IS_ERR(phy)) {
+		dev_err(&pdev->dev, "failed to create PHY\n");
+		return PTR_ERR(phy);
+	}
+
+	if (usb_reset_refcnt++ == 0) {
+		ret = device_reset(&pdev->dev);
+		if (ret) {
+			dev_err(&phy->dev, "Failed to reset USB PHY\n");
+			return ret;
+		}
+	}
+
+	phy_set_drvdata(phy, priv);
+
+	phy_provider =
+		devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate);
+
+	if (IS_ERR(phy_provider)) {
+		usb_reset_refcnt--;
+
+		return PTR_ERR(phy_provider);
+	}
+
+	return 0;
+}
+
+static int phy_meson_usb2_remove(struct platform_device *pdev)
+{
+	usb_reset_refcnt--;
+
+	return 0;
+}
+
+static const struct of_device_id phy_meson_usb2_of_match[] = {
+	{ .compatible = "amlogic,meson8b-usb2-phy", },
+	{ .compatible = "amlogic,meson-gxbb-usb2-phy", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, phy_meson_usb2_of_match);
+
+static struct platform_driver phy_meson_usb2_driver = {
+	.probe	= phy_meson_usb2_probe,
+	.remove = phy_meson_usb2_remove,
+	.driver	= {
+		.name		= "phy-meson-usb2",
+		.of_match_table	= phy_meson_usb2_of_match,
+	},
+};
+module_platform_driver(phy_meson_usb2_driver);
+
+MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>");
+MODULE_DESCRIPTION("Meson USB2 PHY driver");
+MODULE_LICENSE("GPL");
-- 
2.9.3

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