usb: rockchip-phy: implement USB2.0 phy control

So far, Rockchip SoCs have two kinds of USB2.0 phy, such as Synopsys and
Innosilicon. This patch applys dwc2 usb driver framework to implement
phy_init() and phy_off() methods for Synopsys phy on Rockchip platform.

Signed-off-by: Ziyuan Xu <xzy.xu@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>

drivers/usb/phy/Makefile

@@ -7,3 +7,4 @@
 
 obj-$(CONFIG_TWL4030_USB) += twl4030.o
 obj-$(CONFIG_OMAP_USB_PHY) += omap_usb_phy.o
+obj-$(CONFIG_ROCKCHIP_USB2_PHY) += rockchip_usb2_phy.o

drivers/usb/phy/rockchip_usb2_phy.c

@@ -0,0 +1,107 @@
+/*
+ * Copyright 2016 Rockchip Electronics Co., Ltd
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <libfdt.h>
+
+#include "../gadget/dwc2_udc_otg_priv.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define BIT_WRITEABLE_SHIFT	16
+
+struct usb2phy_reg {
+	unsigned int offset;
+	unsigned int bitend;
+	unsigned int bitstart;
+	unsigned int disable;
+	unsigned int enable;
+};
+
+/**
+ * struct rockchip_usb2_phy_cfg: usb-phy port configuration
+ * @port_reset: usb otg per-port reset register
+ * @soft_con: software control usb otg register
+ * @suspend: phy suspend register
+ */
+struct rockchip_usb2_phy_cfg {
+	struct usb2phy_reg port_reset;
+	struct usb2phy_reg soft_con;
+	struct usb2phy_reg suspend;
+};
+
+struct rockchip_usb2_phy_dt_id {
+	char		compatible[128];
+	const void	*data;
+};
+
+static const struct rockchip_usb2_phy_cfg rk3288_pdata = {
+	.port_reset     = {0x00, 12, 12, 0, 1},
+	.soft_con       = {0x08, 2, 2, 0, 1},
+	.suspend	= {0x0c, 5, 0, 0x01, 0x2A},
+};
+
+static struct rockchip_usb2_phy_dt_id rockchip_usb2_phy_dt_ids[] = {
+	{ .compatible = "rockchip,rk3288-usb-phy", .data = &rk3288_pdata },
+	{}
+};
+
+static void property_enable(struct dwc2_plat_otg_data *pdata,
+				  const struct usb2phy_reg *reg, bool en)
+{
+	unsigned int val, mask, tmp;
+
+	tmp = en ? reg->enable : reg->disable;
+	mask = GENMASK(reg->bitend, reg->bitstart);
+	val = (tmp << reg->bitstart) | (mask << BIT_WRITEABLE_SHIFT);
+
+	writel(val, pdata->regs_phy + reg->offset);
+}
+
+
+void otg_phy_init(struct dwc2_udc *dev)
+{
+	struct dwc2_plat_otg_data *pdata = dev->pdata;
+	struct rockchip_usb2_phy_cfg *phy_cfg = NULL;
+	struct rockchip_usb2_phy_dt_id *of_id;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(rockchip_usb2_phy_dt_ids); i++) {
+		of_id = &rockchip_usb2_phy_dt_ids[i];
+		if (fdt_node_check_compatible(gd->fdt_blob, pdata->phy_of_node,
+					      of_id->compatible) == 0) {
+			phy_cfg = (struct rockchip_usb2_phy_cfg *)of_id->data;
+			break;
+		}
+	}
+	if (!phy_cfg) {
+		debug("Can't find device platform data\n");
+
+		hang();
+		return;
+	}
+	pdata->priv = phy_cfg;
+	/* disable software control */
+	property_enable(pdata, &phy_cfg->soft_con, false);
+
+	/* reset otg port */
+	property_enable(pdata, &phy_cfg->port_reset, true);
+	mdelay(1);
+	property_enable(pdata, &phy_cfg->port_reset, false);
+	udelay(1);
+}
+
+void otg_phy_off(struct dwc2_udc *dev)
+{
+	struct dwc2_plat_otg_data *pdata = dev->pdata;
+	struct rockchip_usb2_phy_cfg *phy_cfg = pdata->priv;
+
+	/* enable software control */
+	property_enable(pdata, &phy_cfg->soft_con, true);
+	/* enter suspend */
+	property_enable(pdata, &phy_cfg->suspend, true);
+}

include/usb/dwc2_udc.h

@@ -12,6 +12,8 @@
 #define PHY0_SLEEP              (1 << 5)
 
 struct dwc2_plat_otg_data {
+	void		*priv;
+	int		phy_of_node;
 	int		(*phy_control)(int on);
 	unsigned int	regs_phy;
 	unsigned int	regs_otg;