[PATCH v5 1/5] phy: add a driver for the Rockchip SoC internal USB2.0 PHY

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 <redacted>

---

Changes in v5: None
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@rock-chips.com>
+ * 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;