PHY: sunxi: Add driver for sunxi usb phy

The Allwinner A1x / A2x SoCs have 2 or 3 usb phys which are all accessed
through a single set of registers. Besides this there are also some other
phy related bits which need poking, which are per phy, but shared between the
ohci and ehci controllers, so these are also controlled from this new phy
driver.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

3 files changed, 343 insertions, 0 deletions

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 04312849501d..e677ee01fe8a 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -85,4 +85,15 @@ config PHY_EXYNOS5250_SATA
 	  SATA 3.0 Gb/s, SATA 6.0 Gb/s speeds. It supports one SATA host
 	  port to accept one SATA device.
 
+config PHY_SUN4I_USB
+	tristate "Allwinner sunxi SoC USB PHY driver"
+	depends on ARCH_SUNXI && HAS_IOMEM && OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the transceiver that is part of Allwinner
+	  sunxi SoCs.
+
+	  This driver controls the entire USB PHY block, both the USB OTG
+	  parts, as well as the 2 regular USB 2 host PHYs.
+
 endmenu
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 0d038224a102..5d0b59edaf88 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_PHY_MVEBU_SATA)		+= phy-mvebu-sata.o
 obj-$(CONFIG_OMAP_USB2)			+= phy-omap-usb2.o
 obj-$(CONFIG_TWL4030_USB)		+= phy-twl4030-usb.o
 obj-$(CONFIG_PHY_EXYNOS5250_SATA)	+= phy-exynos5250-sata.o
+obj-$(CONFIG_PHY_SUN4I_USB)		+= phy-sun4i-usb.o
diff --git a/drivers/phy/phy-sun4i-usb.c b/drivers/phy/phy-sun4i-usb.c
new file mode 100644
index 000000000000..e6e6c4ba7145
--- /dev/null
+++ b/drivers/phy/phy-sun4i-usb.c
@@ -0,0 +1,331 @@
+/*
+ * Allwinner sun4i USB phy driver
+ *
+ * Copyright (C) 2014 Hans de Goede <hdegoede@redhat.com>
+ *
+ * Based on code from
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ *
+ * Modelled after: Samsung S5P/EXYNOS SoC series MIPI CSIS/DSIM DPHY driver
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ * Author: Sylwester Nawrocki <s.nawrocki@samsung.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/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+
+#define REG_ISCR			0x00
+#define REG_PHYCTL			0x04
+#define REG_PHYBIST			0x08
+#define REG_PHYTUNE			0x0c
+
+#define PHYCTL_DATA			BIT(7)
+
+#define SUNXI_AHB_ICHR8_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)
+
+/* Common Control Bits for Both PHYs */
+#define PHY_PLL_BW			0x03
+#define PHY_RES45_CAL_EN		0x0c
+
+/* Private Control Bits for Each PHY */
+#define PHY_TX_AMPLITUDE_TUNE		0x20
+#define PHY_TX_SLEWRATE_TUNE		0x22
+#define PHY_VBUSVALID_TH_SEL		0x25
+#define PHY_PULLUP_RES_SEL		0x27
+#define PHY_OTG_FUNC_EN			0x28
+#define PHY_VBUS_DET_EN			0x29
+#define PHY_DISCON_TH_SEL		0x2a
+
+#define MAX_PHYS			3
+
+struct sun4i_usb_phy_data {
+	struct clk *clk;
+	void __iomem *base;
+	struct mutex mutex;
+	int num_phys;
+	u32 disc_thresh;
+	struct sun4i_usb_phy {
+		struct phy *phy;
+		void __iomem *pmu;
+		struct regulator *vbus;
+		struct reset_control *reset;
+		int index;
+	} phys[MAX_PHYS];
+};
+
+#define to_sun4i_usb_phy_data(phy) \
+	container_of((phy), struct sun4i_usb_phy_data, phys[(phy)->index])
+
+static void sun4i_usb_phy_write(struct sun4i_usb_phy *phy, u32 addr, u32 data,
+				int len)
+{
+	struct sun4i_usb_phy_data *phy_data = to_sun4i_usb_phy_data(phy);
+	u32 temp, usbc_bit = BIT(phy->index * 2);
+	int i;
+
+	mutex_lock(&phy_data->mutex);
+
+	for (i = 0; i < len; i++) {
+		temp = readl(phy_data->base + REG_PHYCTL);
+
+		/* clear the address portion */
+		temp &= ~(0xff << 8);
+
+		/* set the address */
+		temp |= ((addr + i) << 8);
+		writel(temp, phy_data->base + REG_PHYCTL);
+
+		/* set the data bit and clear usbc bit*/
+		temp = readb(phy_data->base + REG_PHYCTL);
+		if (data & 0x1)
+			temp |= PHYCTL_DATA;
+		else
+			temp &= ~PHYCTL_DATA;
+		temp &= ~usbc_bit;
+		writeb(temp, phy_data->base + REG_PHYCTL);
+
+		/* pulse usbc_bit */
+		temp = readb(phy_data->base + REG_PHYCTL);
+		temp |= usbc_bit;
+		writeb(temp, phy_data->base + REG_PHYCTL);
+
+		temp = readb(phy_data->base + REG_PHYCTL);
+		temp &= ~usbc_bit;
+		writeb(temp, phy_data->base + REG_PHYCTL);
+
+		data >>= 1;
+	}
+	mutex_unlock(&phy_data->mutex);
+}
+
+static void sun4i_usb_phy_passby(struct sun4i_usb_phy *phy, int enable)
+{
+	u32 bits, reg_value;
+
+	if (!phy->pmu)
+		return;
+
+	bits = SUNXI_AHB_ICHR8_EN | SUNXI_AHB_INCR4_BURST_EN |
+		SUNXI_AHB_INCRX_ALIGN_EN | SUNXI_ULPI_BYPASS_EN;
+
+	reg_value = readl(phy->pmu);
+
+	if (enable)
+		reg_value |= bits;
+	else
+		reg_value &= ~bits;
+
+	writel(reg_value, phy->pmu);
+}
+
+static int sun4i_usb_phy_init(struct phy *_phy)
+{
+	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
+	struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
+	int ret;
+
+	ret = clk_prepare_enable(data->clk);
+	if (ret)
+		return ret;
+
+	ret = reset_control_deassert(phy->reset);
+	if (ret) {
+		clk_disable_unprepare(data->clk);
+		return ret;
+	}
+
+	/* Adjust PHY's magnitude and rate */
+	sun4i_usb_phy_write(phy, PHY_TX_AMPLITUDE_TUNE, 0x14, 5);
+
+	/* Disconnect threshold adjustment */
+	sun4i_usb_phy_write(phy, PHY_DISCON_TH_SEL, data->disc_thresh, 2);
+
+	sun4i_usb_phy_passby(phy, 1);
+
+	return 0;
+}
+
+static int sun4i_usb_phy_exit(struct phy *_phy)
+{
+	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
+	struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
+
+	sun4i_usb_phy_passby(phy, 0);
+	reset_control_assert(phy->reset);
+	clk_disable_unprepare(data->clk);
+
+	return 0;
+}
+
+static int sun4i_usb_phy_power_on(struct phy *_phy)
+{
+	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
+	int ret = 0;
+
+	if (phy->vbus)
+		ret = regulator_enable(phy->vbus);
+
+	return ret;
+}
+
+static int sun4i_usb_phy_power_off(struct phy *_phy)
+{
+	struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
+
+	if (phy->vbus)
+		regulator_disable(phy->vbus);
+
+	return 0;
+}
+
+static struct phy_ops sun4i_usb_phy_ops = {
+	.init		= sun4i_usb_phy_init,
+	.exit		= sun4i_usb_phy_exit,
+	.power_on	= sun4i_usb_phy_power_on,
+	.power_off	= sun4i_usb_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static struct phy *sun4i_usb_phy_xlate(struct device *dev,
+					struct of_phandle_args *args)
+{
+	struct sun4i_usb_phy_data *data = dev_get_drvdata(dev);
+
+	if (WARN_ON(args->args[0] == 0 || args->args[0] >= data->num_phys))
+		return ERR_PTR(-ENODEV);
+
+	return data->phys[args->args[0]].phy;
+}
+
+static int sun4i_usb_phy_probe(struct platform_device *pdev)
+{
+	struct sun4i_usb_phy_data *data;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	void __iomem *pmu = NULL;
+	struct phy_provider *phy_provider;
+	struct reset_control *reset;
+	struct regulator *vbus;
+	struct resource *res;
+	struct phy *phy;
+	char name[16];
+	int i;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	mutex_init(&data->mutex);
+
+	if (of_device_is_compatible(np, "allwinner,sun5i-a13-usb-phy"))
+		data->num_phys = 2;
+	else
+		data->num_phys = 3;
+
+	if (of_device_is_compatible(np, "allwinner,sun4i-a10-usb-phy"))
+		data->disc_thresh = 3;
+	else
+		data->disc_thresh = 2;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy_ctrl");
+	data->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(data->base))
+		return PTR_ERR(data->base);
+
+	data->clk = devm_clk_get(dev, "usb_phy");
+	if (IS_ERR(data->clk)) {
+		dev_err(dev, "could not get usb_phy clock\n");
+		return PTR_ERR(data->clk);
+	}
+
+	/* Skip 0, 0 is the phy for otg which is not yet supported. */
+	for (i = 1; i < data->num_phys; i++) {
+		snprintf(name, sizeof(name), "usb%d_vbus", i);
+		vbus = devm_regulator_get_optional(dev, name);
+		if (IS_ERR(vbus)) {
+			if (PTR_ERR(vbus) == -EPROBE_DEFER)
+				return -EPROBE_DEFER;
+			vbus = NULL;
+		}
+
+		snprintf(name, sizeof(name), "usb%d_reset", i);
+		reset = devm_reset_control_get(dev, name);
+		if (IS_ERR(reset)) {
+			dev_err(dev, "failed to get reset %s\n", name);
+			return PTR_ERR(reset);
+		}
+
+		if (i) { /* No pmu for usbc0 */
+			snprintf(name, sizeof(name), "pmu%d", i);
+			res = platform_get_resource_byname(pdev,
+							IORESOURCE_MEM, name);
+			pmu = devm_ioremap_resource(dev, res);
+			if (IS_ERR(pmu))
+				return PTR_ERR(pmu);
+		}
+
+		phy = devm_phy_create(dev, &sun4i_usb_phy_ops, NULL);
+		if (IS_ERR(phy)) {
+			dev_err(dev, "failed to create PHY %d\n", i);
+			return PTR_ERR(phy);
+		}
+
+		data->phys[i].phy = phy;
+		data->phys[i].pmu = pmu;
+		data->phys[i].vbus = vbus;
+		data->phys[i].reset = reset;
+		data->phys[i].index = i;
+		phy_set_drvdata(phy, &data->phys[i]);
+	}
+
+	dev_set_drvdata(dev, data);
+	phy_provider = devm_of_phy_provider_register(dev, sun4i_usb_phy_xlate);
+	if (IS_ERR(phy_provider))
+		return PTR_ERR(phy_provider);
+
+	return 0;
+}
+
+static const struct of_device_id sun4i_usb_phy_of_match[] = {
+	{ .compatible = "allwinner,sun4i-a10-usb-phy" },
+	{ .compatible = "allwinner,sun5i-a13-usb-phy" },
+	{ .compatible = "allwinner,sun7i-a20-usb-phy" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, sun4i_usb_phy_of_match);
+
+static struct platform_driver sun4i_usb_phy_driver = {
+	.probe	= sun4i_usb_phy_probe,
+	.driver = {
+		.of_match_table	= sun4i_usb_phy_of_match,
+		.name  = "sun4i-usb-phy",
+		.owner = THIS_MODULE,
+	}
+};
+module_platform_driver(sun4i_usb_phy_driver);
+
+MODULE_DESCRIPTION("Allwinner sun4i USB phy driver");
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_LICENSE("GPL v2");