[PATCH V2] phy: ralink-usb: add driver for Mediatek/Ralink

[John Crispin <blogic@openwrt.org>]

Add a driver to setup the USB phy on Mediatek/Ralink SoCs.
The driver is trivial and only sets up power and host mode.

Signed-off-by: John Crispin <blogic@openwrt.org>
---
Changes in V2
* remove refcounting
* drop empty functions
* dont use static globals
* use explicit compatible strings

 .../devicetree/bindings/phy/ralink-usb-phy.txt     |   17 ++
 drivers/phy/Kconfig                                |    8 +
 drivers/phy/Makefile                               |    1 +
 drivers/phy/phy-ralink-usb.c                       |  175 ++++++++++++++++++++
 4 files changed, 201 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/ralink-usb-phy.txt
 create mode 100644 drivers/phy/phy-ralink-usb.c

diff --git a/Documentation/devicetree/bindings/phy/ralink-usb-phy.txt b/Documentation/devicetree/bindings/phy/ralink-usb-phy.txt
new file mode 100644
index 0000000..5b27cad
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/ralink-usb-phy.txt
@@ -0,0 +1,17 @@
+Mediatek/Ralink USB PHY
+
+Required properties:
+ - compatible: ralink,rt3352-usbphy or mediatek,mt7620-usbphy
+ - #phy-cells: should be 0
+ - resets: the two reset controllers for host and device
+ - reset-names: the names of the 2 reset controllers
+
+Example:
+
+usbphy: phy {
+	compatible = "mediatek,mt7620-usbphy";
+	#phy-cells = <0>;
+
+	resets = <&rstctrl 22 &rstctrl 25>;
+	reset-names = "host", "device";
+};
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 03cb3ea..a336a5e 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -341,6 +341,14 @@ config PHY_XGENE
 	help
 	  This option enables support for APM X-Gene SoC multi-purpose PHY.
 
+config PHY_RALINK_USB
+	tristate "Ralink USB PHY driver"
+	select GENERIC_PHY
+	depends on RALINK
+	help
+	  This option enables support for the Ralink USB PHY found inside
+	  RT3352 and MT7620.
+
 config PHY_STIH407_USB
 	tristate "STMicroelectronics USB2 picoPHY driver for STiH407 family"
 	depends on RESET_CONTROLLER
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 075db1a..c840787 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -48,3 +48,4 @@ obj-$(CONFIG_PHY_TUSB1210)		+= phy-tusb1210.o
 obj-$(CONFIG_PHY_BRCMSTB_SATA)		+= phy-brcmstb-sata.o
 obj-$(CONFIG_PHY_PISTACHIO_USB)		+= phy-pistachio-usb.o
 obj-$(CONFIG_PHY_CYGNUS_PCIE)		+= phy-bcm-cygnus-pcie.o
+obj-$(CONFIG_PHY_RALINK_USB)		+= phy-ralink-usb.o
diff --git a/drivers/phy/phy-ralink-usb.c b/drivers/phy/phy-ralink-usb.c
new file mode 100644
index 0000000..6e045a8
--- /dev/null
+++ b/drivers/phy/phy-ralink-usb.c
@@ -0,0 +1,175 @@
+/*
+ * Allwinner ralink USB phy driver
+ *
+ * Copyright (C) 2016 John Crispin <blogic@openwrt.org>
+ *
+ * Based on code from
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/of_platform.h>
+
+#include <asm/mach-ralink/ralink_regs.h>
+
+#define RT_SYSC_REG_SYSCFG1		0x014
+#define RT_SYSC_REG_CLKCFG1		0x030
+#define RT_SYSC_REG_USB_PHY_CFG		0x05c
+
+#define RT_RSTCTRL_UDEV			BIT(25)
+#define RT_RSTCTRL_UHST			BIT(22)
+#define RT_SYSCFG1_USB0_HOST_MODE	BIT(10)
+
+#define MT7620_CLKCFG1_UPHY0_CLK_EN	BIT(25)
+#define MT7620_CLKCFG1_UPHY1_CLK_EN	BIT(22)
+#define RT_CLKCFG1_UPHY1_CLK_EN		BIT(20)
+#define RT_CLKCFG1_UPHY0_CLK_EN		BIT(18)
+
+#define USB_PHY_UTMI_8B60M		BIT(1)
+#define UDEV_WAKEUP			BIT(0)
+
+struct ralink_usb_phy {
+	struct reset_control	*rstdev;
+	struct reset_control	*rsthost;
+	u32			clk;
+	struct phy		*phy;
+};
+
+static int ralink_usb_phy_power_on(struct phy *_phy)
+{
+	struct ralink_usb_phy *phy = phy_get_drvdata(_phy);
+	u32 t;
+
+	/* enable the phy */
+	rt_sysc_m32(0, phy->clk, RT_SYSC_REG_CLKCFG1);
+
+	/* setup host mode */
+	rt_sysc_m32(0, RT_SYSCFG1_USB0_HOST_MODE, RT_SYSC_REG_SYSCFG1);
+
+	/* deassert the reset lines */
+	reset_control_deassert(phy->rsthost);
+	reset_control_deassert(phy->rstdev);
+
+	/*
+	 * The SDK kernel had a delay of 100ms. however on device
+	 * testing showed that 10ms is enough
+	 */
+	mdelay(10);
+
+	/* print some status info */
+	t = rt_sysc_r32(RT_SYSC_REG_USB_PHY_CFG);
+	dev_info(&phy->phy->dev, "remote usb device wakeup %s\n",
+		(t & UDEV_WAKEUP) ? ("enabled") : ("disabled"));
+	if (t & USB_PHY_UTMI_8B60M)
+		dev_info(&phy->phy->dev, "UTMI 8bit 60MHz\n");
+	else
+		dev_info(&phy->phy->dev, "UTMI 16bit 30MHz\n");
+
+	return 0;
+}
+
+static int ralink_usb_phy_power_off(struct phy *_phy)
+{
+	struct ralink_usb_phy *phy = phy_get_drvdata(_phy);
+
+	/* disable the phy */
+	rt_sysc_m32(phy->clk, 0, RT_SYSC_REG_CLKCFG1);
+
+	/* assert the reset lines */
+	reset_control_assert(phy->rstdev);
+	reset_control_assert(phy->rsthost);
+
+	return 0;
+}
+
+static struct phy_ops ralink_usb_phy_ops = {
+	.power_on	= ralink_usb_phy_power_on,
+	.power_off	= ralink_usb_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static const struct of_device_id ralink_usb_phy_of_match[] = {
+	{
+		.compatible = "ralink,rt3352-usbphy",
+		.data = (void *) (RT_CLKCFG1_UPHY1_CLK_EN |
+				  RT_CLKCFG1_UPHY0_CLK_EN)
+	},
+	{
+		.compatible = "mediatek,mt7620-usbphy",
+		.data = (void *) (MT7620_CLKCFG1_UPHY1_CLK_EN |
+				  MT7620_CLKCFG1_UPHY0_CLK_EN) },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ralink_usb_phy_of_match);
+
+static int ralink_usb_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct phy_provider *phy_provider;
+	const struct of_device_id *match;
+	struct ralink_usb_phy *phy;
+
+	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	match = of_match_device(ralink_usb_phy_of_match, &pdev->dev);
+	if (!match)
+		return -ENODEV;
+
+	phy->clk = (int) match->data;
+
+	phy->rsthost = devm_reset_control_get(&pdev->dev, "host");
+	if (IS_ERR(phy->rsthost)) {
+		dev_err(dev, "host reset is missing\n");
+		return PTR_ERR(phy->rsthost);
+	}
+
+	phy->rstdev = devm_reset_control_get(&pdev->dev, "device");
+	if (IS_ERR(phy->rstdev)) {
+		dev_err(dev, "device reset is missing\n");
+		return PTR_ERR(phy->rstdev);
+	}
+
+	phy->phy = devm_phy_create(dev, NULL, &ralink_usb_phy_ops);
+	if (IS_ERR(phy->phy)) {
+		dev_err(dev, "failed to create PHY\n");
+		return PTR_ERR(phy->phy);
+	}
+	phy_set_drvdata(phy->phy, phy);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static struct platform_driver ralink_usb_phy_driver = {
+	.probe	= ralink_usb_phy_probe,
+	.driver = {
+		.of_match_table	= ralink_usb_phy_of_match,
+		.name  = "ralink-usb-phy",
+	}
+};
+module_platform_driver(ralink_usb_phy_driver);
+
+MODULE_DESCRIPTION("Ralink USB phy driver");
+MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
+MODULE_LICENSE("GPL v2");
-- 
1.7.10.4