[PATCH v4 1/5] phy: add a driver for the Rockchip SoC internal USB2.0 PHY

[Yunzhi Li]

This patch to add a generic PHY driver for ROCKCHIP usb PHYs,
currently this driver can support RK3288. The RK3288 SoC have
three independent USB PHY IPs which are all configured through a
set of registers located in the GRF (general register files)
module.

Signed-off-by: Yunzhi Li <lyz@xxxxxxxxxxxxxx>

---

Changes in v4:
- Get number of PHYs from device tree.
- Model each PHY as subnode of the phy provider node.

Changes in v3:
- Use BIT macro instead of bit shift ops.
- Rename the config entry to PHY_ROCKCHIP_USB.

 drivers/phy/Kconfig            |   7 ++
 drivers/phy/Makefile           |   1 +
 drivers/phy/phy-rockchip-usb.c | 211 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 219 insertions(+)
 create mode 100644 drivers/phy/phy-rockchip-usb.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index ccad880..8a39d2a 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -239,6 +239,13 @@ config PHY_QCOM_IPQ806X_SATA
 	depends on OF
 	select GENERIC_PHY
 
+config PHY_ROCKCHIP_USB2
+	tristate "Rockchip USB2 PHY Driver"
+	depends on ARCH_ROCKCHIP && OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the Rockchip USB 2.0 PHY.
+
 config PHY_ST_SPEAR1310_MIPHY
 	tristate "ST SPEAR1310-MIPHY driver"
 	select GENERIC_PHY
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index aa74f96..8a13f72 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -28,6 +28,7 @@ phy-exynos-usb2-$(CONFIG_PHY_EXYNOS5250_USB2)	+= phy-exynos5250-usb2.o
 phy-exynos-usb2-$(CONFIG_PHY_S5PV210_USB2)	+= phy-s5pv210-usb2.o
 obj-$(CONFIG_PHY_EXYNOS5_USBDRD)	+= phy-exynos5-usbdrd.o
 obj-$(CONFIG_PHY_QCOM_APQ8064_SATA)	+= phy-qcom-apq8064-sata.o
+obj-$(CONFIG_PHY_ROCKCHIP_USB2) += phy-rockchip-usb.o
 obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA)	+= phy-qcom-ipq806x-sata.o
 obj-$(CONFIG_PHY_ST_SPEAR1310_MIPHY)	+= phy-spear1310-miphy.o
 obj-$(CONFIG_PHY_ST_SPEAR1340_MIPHY)	+= phy-spear1340-miphy.o
diff --git a/drivers/phy/phy-rockchip-usb.c b/drivers/phy/phy-rockchip-usb.c
new file mode 100644
index 0000000..0317c21
--- /dev/null
+++ b/drivers/phy/phy-rockchip-usb.c
@@ -0,0 +1,211 @@
+/*
+ * Rockchip usb PHY driver
+ *
+ * Copyright (C) 2014 Yunzhi Li <lyz@xxxxxxxxxxxxxx>
+ * Copyright (C) 2014 ROCKCHIP, Inc.
+ *
+ * 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.
+ *
+ * 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>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#define ROCKCHIP_RK3288_UOC(n)	(0x320 + n * 0x14)
+
+/*
+ * The higher 16-bit of this register is used for write protection
+ * only if BIT(13 + 16) set to 1 the BIT(13) can be written.
+ */
+#define SIDDQ_MSK		BIT(13 + 16)
+#define SIDDQ_ON		BIT(13)
+#define SIDDQ_OFF		(0 << 13)
+
+struct rockchip_usb_phy {
+	struct regmap	*reg_base;
+	unsigned int	reg_offset;
+	struct clk	*clk;
+	struct phy	*phy;
+	unsigned	index;
+};
+
+struct rockchip_usb_phy_priv {
+	struct rockchip_usb_phy	*phys;
+	unsigned		nphys;
+};
+
+static int rockchip_usb_phy_power(struct rockchip_usb_phy *phy,
+					   bool siddq)
+{
+	return regmap_write(phy->reg_base, phy->reg_offset,
+			    SIDDQ_MSK | (siddq ? SIDDQ_ON : SIDDQ_OFF));
+}
+
+static int rockchip_usb_phy_power_off(struct phy *_phy)
+{
+	struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);
+	int ret = 0;
+
+	/* Power down usb phy analog blocks by set siddq 1 */
+	ret = rockchip_usb_phy_power(phy, 1);
+	if (ret)
+		return ret;
+
+	clk_disable_unprepare(phy->clk);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int rockchip_usb_phy_power_on(struct phy *_phy)
+{
+	struct rockchip_usb_phy *phy = phy_get_drvdata(_phy);
+	int ret = 0;
+
+	ret = clk_prepare_enable(phy->clk);
+	if (ret)
+		return ret;
+
+	/* Power up usb phy analog blocks by set siddq 0 */
+	ret = rockchip_usb_phy_power(phy, 0);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static struct phy *rockchip_usb_phy_xlate(struct device *dev,
+					struct of_phandle_args *args)
+{
+	struct rockchip_usb_phy_priv *priv = dev_get_drvdata(dev);
+	int i;
+
+	if (WARN_ON(args->args[0] >= priv->nphys))
+		return ERR_PTR(-ENODEV);
+
+	for (i = 0; i < priv->nphys; i++) {
+		if (priv->phys[i].index == args->args[0])
+			break;
+	}
+
+	if (i == priv->nphys)
+		return ERR_PTR(-ENODEV);
+
+	return priv->phys[i].phy;
+}
+
+static struct phy_ops ops = {
+	.power_on	= rockchip_usb_phy_power_on,
+	.power_off	= rockchip_usb_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static int rockchip_usb_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rockchip_usb_phy *rk_phy;
+	struct rockchip_usb_phy_priv *priv;
+	struct phy_provider *phy_provider;
+	struct device_node *child;
+	struct regmap *grf;
+	unsigned int phy_id;
+
+	grf = syscon_regmap_lookup_by_phandle(dev->of_node, "rockchip,grf");
+	if (IS_ERR(grf)) {
+		dev_err(&pdev->dev, "Missing rockchip,grf property\n");
+		return PTR_ERR(grf);
+	}
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	/* Get number of phys from device tree */
+	priv->nphys = of_get_child_count(dev->of_node);
+	if (priv->nphys == 0)
+		return -ENODEV;
+
+	priv->phys = devm_kzalloc(dev, priv->nphys * sizeof(*priv->phys),
+				  GFP_KERNEL);
+	if (!priv->phys)
+		return -ENOMEM;
+
+	rk_phy = priv->phys;
+	for_each_available_child_of_node(dev->of_node, child) {
+		if (of_property_read_u32(child, "reg", &phy_id)) {
+			dev_err(dev, "missing reg property in node %s\n",
+				child->name);
+			return -EINVAL;
+		}
+
+		if (phy_id < 0 || phy_id >= priv->nphys) {
+			dev_err(dev, "invalid phy id\n");
+			return -EINVAL;
+		}
+
+		rk_phy->reg_offset = ROCKCHIP_RK3288_UOC(phy_id);
+		rk_phy->reg_base = grf;
+
+		rk_phy->clk = of_clk_get(child, 0);
+		if (IS_ERR(rk_phy->clk)) {
+			dev_warn(dev, "failed to get clock\n");
+			rk_phy->clk = NULL;
+		}
+
+		rk_phy->phy = devm_phy_create(dev, NULL, &ops);
+		if (IS_ERR(rk_phy->phy)) {
+			dev_err(dev, "failed to create PHY %d\n", phy_id);
+			return PTR_ERR(rk_phy->phy);
+		}
+		phy_set_drvdata(rk_phy->phy, rk_phy);
+
+		rk_phy->index = phy_id;
+		rk_phy++;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	phy_provider = devm_of_phy_provider_register(dev,
+						     rockchip_usb_phy_xlate);
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct of_device_id rockchip_usb_phy_dt_ids[] = {
+	{ .compatible = "rockchip,rk3288-usb-phy" },
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, rockchip_usb_phy_dt_ids);
+
+static struct platform_driver rockchip_usb_driver = {
+	.probe		= rockchip_usb_phy_probe,
+	.driver		= {
+		.name	= "rockchip-usb-phy",
+		.owner	= THIS_MODULE,
+		.of_match_table = rockchip_usb_phy_dt_ids,
+	},
+};
+
+module_platform_driver(rockchip_usb_driver);
+
+MODULE_AUTHOR("Yunzhi Li <lyz@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Rockchip USB 2.0 PHY driver");
+MODULE_LICENSE("GPL v2");
-- 
2.0.0


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