phy: Add driver to support individual USB PHYs on sun9i

Unlike previous Allwinner SoCs, there is no central PHY control block
on the A80. Also, OTG support is completely split off into a different
controller.

This adds a new driver to support the regular USB PHYs.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Documentation/devicetree/bindings/phy/sun9i-usb-phy.txt

+Allwinner sun9i USB PHY
+-----------------------
+
+Required properties:
+- compatible : should be one of
+  * allwinner,sun9i-a80-usb-phy
+- reg : a list of offset + length pairs
+- #phy-cells : from the generic phy bindings, must be 0
+- phy_type : "hsic" for HSIC usage;
+	     other values or absence of this property indicates normal USB
+- clocks : phandle + clock specifier for the phy clocks
+- clock-names : depending on the "phy_type" property,
+  * "phy" for normal USB
+  * "hsic_480M", "hsic_12M" for HSIC
+- resets : a list of phandle + reset specifier pairs
+- reset-names : depending on the "phy_type" property,
+  * "phy" for normal USB
+  * "hsic" for HSIC
+
+Optional Properties:
+- phy-supply : from the generic phy bindings, a phandle to a regulator that
+	       provides power to VBUS.
+
+It is recommended to list all clocks and resets available.
+The driver will only use those matching the phy_type.
+
+Example:
+	usbphy1: phy@00a01800 {
+		compatible = "allwinner,sun9i-a80-usb-phy";
+		reg = <0x00a01800 0x4>;
+		clocks = <&usb_phy_clk 2>, <&usb_phy_clk 10>,
+		       <&usb_phy_clk 3>;
+		clock-names = "hsic_480M", "hsic_12M", "phy";
+		resets = <&usb_phy_clk 18>, <&usb_phy_clk 19>;
+		reset-names = "hsic", "phy";
+		status = "disabled";
+		#phy-cells = <0>;
+	};

drivers/phy/Kconfig

@@ -181,6 +181,17 @@ config PHY_SUN4I_USB
 	  This driver controls the entire USB PHY block, both the USB OTG
 	  parts, as well as the 2 regular USB 2 host PHYs.
 
+config PHY_SUN9I_USB
+	tristate "Allwinner sun9i SoC USB PHY driver"
+	depends on ARCH_SUNXI && HAS_IOMEM && OF
+	depends on RESET_CONTROLLER
+	select GENERIC_PHY
+	help
+	  Enable this to support the transceiver that is part of Allwinner
+	  sun9i SoCs.
+
+	  This driver controls each individual USB 2 host PHY.
+
 config PHY_SAMSUNG_USB2
 	tristate "Samsung USB 2.0 PHY driver"
 	depends on HAS_IOMEM

drivers/phy/Makefile

@@ -21,6 +21,7 @@ obj-$(CONFIG_TWL4030_USB)		+= phy-twl4030-usb.o
 obj-$(CONFIG_PHY_EXYNOS5250_SATA)	+= phy-exynos5250-sata.o
 obj-$(CONFIG_PHY_HIX5HD2_SATA)		+= phy-hix5hd2-sata.o
 obj-$(CONFIG_PHY_SUN4I_USB)		+= phy-sun4i-usb.o
+obj-$(CONFIG_PHY_SUN9I_USB)		+= phy-sun9i-usb.o
 obj-$(CONFIG_PHY_SAMSUNG_USB2)		+= phy-exynos-usb2.o
 phy-exynos-usb2-y			+= phy-samsung-usb2.o
 phy-exynos-usb2-$(CONFIG_PHY_EXYNOS4210_USB2)	+= phy-exynos4210-usb2.o

drivers/phy/phy-sun9i-usb.c

+/*
+ * Allwinner sun9i USB phy driver
+ *
+ * Copyright (C) 2014-2015 Chen-Yu Tsai <wens@csie.org>
+ *
+ * Based on phy-sun4i-usb.c from
+ * Hans de Goede <hdegoede@redhat.com>
+ *
+ * and 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/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/usb/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#define SUNXI_AHB_INCR16_BURST_EN	BIT(11)
+#define SUNXI_AHB_INCR8_BURST_EN	BIT(10)
+#define SUNXI_AHB_INCR4_BURST_EN	BIT(9)
+#define SUNXI_AHB_INCRX_ALIGN_EN	BIT(8)
+#define SUNXI_ULPI_BYPASS_EN		BIT(0)
+
+/* usb1 HSIC specific bits */
+#define SUNXI_EHCI_HS_FORCE		BIT(20)
+#define SUNXI_HSIC_CONNECT_DET		BIT(17)
+#define SUNXI_HSIC_CONNECT_INT		BIT(16)
+#define SUNXI_HSIC			BIT(1)
+
+struct sun9i_usb_phy {
+	struct phy *phy;
+	void __iomem *pmu;
+	struct reset_control *reset;
+	struct clk *clk;
+	struct clk *hsic_clk;
+	enum usb_phy_interface type;
+};
+
+static void sun9i_usb_phy_passby(struct sun9i_usb_phy *phy, int enable)
+{
+	u32 bits, reg_value;
+
+	bits = SUNXI_AHB_INCR16_BURST_EN | SUNXI_AHB_INCR8_BURST_EN |
+		SUNXI_AHB_INCR4_BURST_EN | SUNXI_AHB_INCRX_ALIGN_EN |
+		SUNXI_ULPI_BYPASS_EN;
+
+	if (phy->type == USBPHY_INTERFACE_MODE_HSIC)
+		bits |= SUNXI_HSIC | SUNXI_EHCI_HS_FORCE |
+			SUNXI_HSIC_CONNECT_DET | SUNXI_HSIC_CONNECT_INT;
+
+	reg_value = readl(phy->pmu);
+
+	if (enable)
+		reg_value |= bits;
+	else
+		reg_value &= ~bits;
+
+	writel(reg_value, phy->pmu);
+}
+
+static int sun9i_usb_phy_init(struct phy *_phy)
+{
+	struct sun9i_usb_phy *phy = phy_get_drvdata(_phy);
+	int ret;
+
+	ret = clk_prepare_enable(phy->clk);
+	if (ret)
+		goto err_clk;
+
+	ret = clk_prepare_enable(phy->hsic_clk);
+	if (ret)
+		goto err_hsic_clk;
+
+	ret = reset_control_deassert(phy->reset);
+	if (ret)
+		goto err_reset;
+
+	sun9i_usb_phy_passby(phy, 1);
+	return 0;
+
+err_reset:
+	clk_disable_unprepare(phy->hsic_clk);
+
+err_hsic_clk:
+	clk_disable_unprepare(phy->clk);
+
+err_clk:
+	return ret;
+}
+
+static int sun9i_usb_phy_exit(struct phy *_phy)
+{
+	struct sun9i_usb_phy *phy = phy_get_drvdata(_phy);
+
+	sun9i_usb_phy_passby(phy, 0);
+	reset_control_assert(phy->reset);
+	clk_disable_unprepare(phy->hsic_clk);
+	clk_disable_unprepare(phy->clk);
+
+	return 0;
+}
+
+static struct phy_ops sun9i_usb_phy_ops = {
+	.init		= sun9i_usb_phy_init,
+	.exit		= sun9i_usb_phy_exit,
+	.owner		= THIS_MODULE,
+};
+
+static int sun9i_usb_phy_probe(struct platform_device *pdev)
+{
+	struct sun9i_usb_phy *phy;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct phy_provider *phy_provider;
+	struct resource *res;
+
+	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->type = of_usb_get_phy_mode(np);
+	if (phy->type == USBPHY_INTERFACE_MODE_HSIC) {
+		phy->clk = devm_clk_get(dev, "hsic_480M");
+		if (IS_ERR(phy->clk)) {
+			dev_err(dev, "failed to get hsic_480M clock\n");
+			return PTR_ERR(phy->clk);
+		}
+
+		phy->hsic_clk = devm_clk_get(dev, "hsic_12M");
+		if (IS_ERR(phy->clk)) {
+			dev_err(dev, "failed to get hsic_12M clock\n");
+			return PTR_ERR(phy->clk);
+		}
+
+		phy->reset = devm_reset_control_get(dev, "hsic");
+		if (IS_ERR(phy->reset)) {
+			dev_err(dev, "failed to get reset control\n");
+			return PTR_ERR(phy->reset);
+		}
+	} else {
+		phy->clk = devm_clk_get(dev, "phy");
+		if (IS_ERR(phy->clk)) {
+			dev_err(dev, "failed to get phy clock\n");
+			return PTR_ERR(phy->clk);
+		}
+
+		phy->reset = devm_reset_control_get(dev, "phy");
+		if (IS_ERR(phy->reset)) {
+			dev_err(dev, "failed to get reset control\n");
+			return PTR_ERR(phy->reset);
+		}
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	phy->pmu = devm_ioremap_resource(dev, res);
+	if (IS_ERR(phy->pmu))
+		return PTR_ERR(phy->pmu);
+
+	phy->phy = devm_phy_create(dev, NULL, &sun9i_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 const struct of_device_id sun9i_usb_phy_of_match[] = {
+	{ .compatible = "allwinner,sun9i-a80-usb-phy" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, sun9i_usb_phy_of_match);
+
+static struct platform_driver sun9i_usb_phy_driver = {
+	.probe	= sun9i_usb_phy_probe,
+	.driver = {
+		.of_match_table	= sun9i_usb_phy_of_match,
+		.name  = "sun9i-usb-phy",
+	}
+};
+module_platform_driver(sun9i_usb_phy_driver);
+
+MODULE_DESCRIPTION("Allwinner sun9i USB phy driver");
+MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
+MODULE_LICENSE("GPL");