phy: Add new Exynos USB 2.0 PHY driver

Add a new driver for the Exynos USB 2.0 PHY. The new driver uses the generic
PHY framework. The driver includes support for the Exynos 4x10 and 4x12
SoC families.

Signed-off-by: Kamil Debski <k.debski@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

1 files changed, 222 insertions, 0 deletions

diff --git a/drivers/phy/phy-samsung-usb2.c b/drivers/phy/phy-samsung-usb2.c
new file mode 100644
index 00000000000..c3b771907f1
--- /dev/null
+++ b/drivers/phy/phy-samsung-usb2.c
@@ -0,0 +1,222 @@
+/*
+ * Samsung SoC USB 1.1/2.0 PHY driver
+ *
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ * Author: Kamil Debski <k.debski@samsung.com>
+ *
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include "phy-samsung-usb2.h"
+
+static int samsung_usb2_phy_power_on(struct phy *phy)
+{
+	struct samsung_usb2_phy_instance *inst = phy_get_drvdata(phy);
+	struct samsung_usb2_phy_driver *drv = inst->drv;
+	int ret;
+
+	dev_dbg(drv->dev, "Request to power_on \"%s\" usb phy\n",
+		inst->cfg->label);
+	ret = clk_prepare_enable(drv->clk);
+	if (ret)
+		goto err_main_clk;
+	ret = clk_prepare_enable(drv->ref_clk);
+	if (ret)
+		goto err_instance_clk;
+	if (inst->cfg->power_on) {
+		spin_lock(&drv->lock);
+		ret = inst->cfg->power_on(inst);
+		spin_unlock(&drv->lock);
+	}
+
+	return 0;
+
+err_instance_clk:
+	clk_disable_unprepare(drv->clk);
+err_main_clk:
+	return ret;
+}
+
+static int samsung_usb2_phy_power_off(struct phy *phy)
+{
+	struct samsung_usb2_phy_instance *inst = phy_get_drvdata(phy);
+	struct samsung_usb2_phy_driver *drv = inst->drv;
+	int ret = 0;
+
+	dev_dbg(drv->dev, "Request to power_off \"%s\" usb phy\n",
+		inst->cfg->label);
+	if (inst->cfg->power_off) {
+		spin_lock(&drv->lock);
+		ret = inst->cfg->power_off(inst);
+		spin_unlock(&drv->lock);
+	}
+	clk_disable_unprepare(drv->ref_clk);
+	clk_disable_unprepare(drv->clk);
+	return ret;
+}
+
+static struct phy_ops samsung_usb2_phy_ops = {
+	.power_on	= samsung_usb2_phy_power_on,
+	.power_off	= samsung_usb2_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static struct phy *samsung_usb2_phy_xlate(struct device *dev,
+					struct of_phandle_args *args)
+{
+	struct samsung_usb2_phy_driver *drv;
+
+	drv = dev_get_drvdata(dev);
+	if (!drv)
+		return ERR_PTR(-EINVAL);
+
+	if (WARN_ON(args->args[0] >= drv->cfg->num_phys))
+		return ERR_PTR(-ENODEV);
+
+	return drv->instances[args->args[0]].phy;
+}
+
+static const struct of_device_id samsung_usb2_phy_of_match[] = {
+#ifdef CONFIG_PHY_EXYNOS4210_USB2
+	{
+		.compatible = "samsung,exynos4210-usb2-phy",
+		.data = &exynos4210_usb2_phy_config,
+	},
+#endif
+#ifdef CONFIG_PHY_EXYNOS4X12_USB2
+	{
+		.compatible = "samsung,exynos4x12-usb2-phy",
+		.data = &exynos4x12_usb2_phy_config,
+	},
+#endif
+	{ },
+};
+
+static int samsung_usb2_phy_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	const struct samsung_usb2_phy_config *cfg;
+	struct device *dev = &pdev->dev;
+	struct phy_provider *phy_provider;
+	struct resource *mem;
+	struct samsung_usb2_phy_driver *drv;
+	int i, ret;
+
+	if (!pdev->dev.of_node) {
+		dev_err(dev, "This driver is required to be instantiated from device tree\n");
+		return -EINVAL;
+	}
+
+	match = of_match_node(samsung_usb2_phy_of_match, pdev->dev.of_node);
+	if (!match) {
+		dev_err(dev, "of_match_node() failed\n");
+		return -EINVAL;
+	}
+	cfg = match->data;
+
+	drv = devm_kzalloc(dev, sizeof(struct samsung_usb2_phy_driver) +
+		cfg->num_phys * sizeof(struct samsung_usb2_phy_instance),
+								GFP_KERNEL);
+	if (!drv)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, drv);
+	spin_lock_init(&drv->lock);
+
+	drv->cfg = cfg;
+	drv->dev = dev;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	drv->reg_phy = devm_ioremap_resource(dev, mem);
+	if (IS_ERR(drv->reg_phy)) {
+		dev_err(dev, "Failed to map register memory (phy)\n");
+		return PTR_ERR(drv->reg_phy);
+	}
+
+	drv->reg_pmu = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+		"samsung,pmureg-phandle");
+	if (IS_ERR(drv->reg_pmu)) {
+		dev_err(dev, "Failed to map PMU registers (via syscon)\n");
+		return PTR_ERR(drv->reg_pmu);
+	}
+
+	if (drv->cfg->has_mode_switch) {
+		drv->reg_sys = syscon_regmap_lookup_by_phandle(
+				pdev->dev.of_node, "samsung,sysreg-phandle");
+		if (IS_ERR(drv->reg_sys)) {
+			dev_err(dev, "Failed to map system registers (via syscon)\n");
+			return PTR_ERR(drv->reg_sys);
+		}
+	}
+
+	drv->clk = devm_clk_get(dev, "phy");
+	if (IS_ERR(drv->clk)) {
+		dev_err(dev, "Failed to get clock of phy controller\n");
+		return PTR_ERR(drv->clk);
+	}
+
+	drv->ref_clk = devm_clk_get(dev, "ref");
+	if (IS_ERR(drv->ref_clk)) {
+		dev_err(dev, "Failed to get reference clock for the phy controller\n");
+		return PTR_ERR(drv->ref_clk);
+	}
+
+	drv->ref_rate = clk_get_rate(drv->ref_clk);
+	if (drv->cfg->rate_to_clk) {
+		ret = drv->cfg->rate_to_clk(drv->ref_rate, &drv->ref_reg_val);
+		if (ret)
+			return ret;
+	}
+
+	for (i = 0; i < drv->cfg->num_phys; i++) {
+		char *label = drv->cfg->phys[i].label;
+		struct samsung_usb2_phy_instance *p = &drv->instances[i];
+
+		dev_dbg(dev, "Creating phy \"%s\"\n", label);
+		p->phy = devm_phy_create(dev, &samsung_usb2_phy_ops, NULL);
+		if (IS_ERR(p->phy)) {
+			dev_err(drv->dev, "Failed to create usb2_phy \"%s\"\n",
+				label);
+			return PTR_ERR(p->phy);
+		}
+
+		p->cfg = &drv->cfg->phys[i];
+		p->drv = drv;
+		phy_set_bus_width(p->phy, 8);
+		phy_set_drvdata(p->phy, p);
+	}
+
+	phy_provider = devm_of_phy_provider_register(dev,
+							samsung_usb2_phy_xlate);
+	if (IS_ERR(phy_provider)) {
+		dev_err(drv->dev, "Failed to register phy provider\n");
+		return PTR_ERR(phy_provider);
+	}
+
+	return 0;
+}
+
+static struct platform_driver samsung_usb2_phy_driver = {
+	.probe	= samsung_usb2_phy_probe,
+	.driver = {
+		.of_match_table	= samsung_usb2_phy_of_match,
+		.name		= "samsung-usb2-phy",
+		.owner		= THIS_MODULE,
+	}
+};
+
+module_platform_driver(samsung_usb2_phy_driver);
+MODULE_DESCRIPTION("Samsung S5P/EXYNOS SoC USB PHY driver");
+MODULE_AUTHOR("Kamil Debski <k.debski@samsung.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:samsung-usb2-phy");