From 4c834b965aa3cde447e733b1cd338c02ffd04cd2 Mon Sep 17 00:00:00 2001
From: Patrice Chotard <patrice.chotard@st.com>
Date: Fri, 10 Aug 2018 17:12:14 +0200
Subject: [PATCH] board: st: stm32mp1: Add usb gadget support

Enable USB gadget support using DWC2 driver
Populate board_usb_init() to initialize clocks,
phy, reset and data needed for DWC2 IP.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
---
 board/st/stm32mp1/stm32mp1.c | 168 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 168 insertions(+)

diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index bfc8ab6..54feca0 100644
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -5,13 +5,181 @@
 #include <config.h>
 #include <common.h>
 #include <led.h>
+#include <clk.h>
+#include <dm.h>
+#include <generic-phy.h>
+#include <phy.h>
+#include <reset.h>
+#include <usb.h>
 #include <asm/arch/stm32.h>
+#include <asm/io.h>
+#include <power/regulator.h>
+#include <usb/dwc2_udc.h>
 
 /*
  * Get a global data pointer
  */
 DECLARE_GLOBAL_DATA_PTR;
 
+#define STM32MP_GUSBCFG 0x40002407
+
+#define STM32MP_GGPIO 0x38
+#define STM32MP_GGPIO_VBUS_SENSING BIT(21)
+
+static struct dwc2_plat_otg_data stm32mp_otg_data = {
+	.usb_gusbcfg = STM32MP_GUSBCFG,
+};
+
+static struct reset_ctl usbotg_reset;
+
+int board_usb_init(int index, enum usb_init_type init)
+{
+	struct fdtdec_phandle_args args;
+	struct udevice *dev;
+	const void *blob = gd->fdt_blob;
+	struct clk clk;
+	struct phy phy;
+	int node;
+	int phy_provider;
+	int ret;
+
+	/* find the usb otg node */
+	node = fdt_node_offset_by_compatible(blob, -1, "snps,dwc2");
+	if (node < 0) {
+		debug("Not found usb_otg device\n");
+		return -ENODEV;
+	}
+
+	if (!fdtdec_get_is_enabled(blob, node)) {
+		debug("stm32 usbotg is disabled in the device tree\n");
+		return -ENODEV;
+	}
+
+	/* Enable clock */
+	ret = fdtdec_parse_phandle_with_args(blob, node, "clocks",
+					     "#clock-cells", 0, 0, &args);
+	if (ret) {
+		debug("usbotg has no clocks defined in the device tree\n");
+		return ret;
+	}
+
+	ret = uclass_get_device_by_of_offset(UCLASS_CLK, args.node, &dev);
+	if (ret)
+		return ret;
+
+	if (args.args_count != 1) {
+		debug("Can't find clock ID in the device tree\n");
+		return -ENODATA;
+	}
+
+	clk.dev = dev;
+	clk.id = args.args[0];
+
+	ret = clk_enable(&clk);
+	if (ret) {
+		debug("Failed to enable usbotg clock\n");
+		return ret;
+	}
+
+	/* Reset */
+	ret = fdtdec_parse_phandle_with_args(blob, node, "resets",
+					     "#reset-cells", 0, 0, &args);
+	if (ret) {
+		debug("usbotg has no resets defined in the device tree\n");
+		goto clk_err;
+	}
+
+	ret = uclass_get_device_by_of_offset(UCLASS_RESET, args.node, &dev);
+	if (ret || args.args_count != 1)
+		goto clk_err;
+
+	usbotg_reset.dev = dev;
+	usbotg_reset.id = args.args[0];
+
+	reset_assert(&usbotg_reset);
+	udelay(2);
+	reset_deassert(&usbotg_reset);
+
+	/* Get USB PHY */
+	ret = fdtdec_parse_phandle_with_args(blob, node, "phys",
+					     "#phy-cells", 0, 0, &args);
+	if (!ret) {
+		phy_provider = fdt_parent_offset(blob, args.node);
+		ret = uclass_get_device_by_of_offset(UCLASS_PHY,
+						     phy_provider, &dev);
+		if (ret)
+			goto clk_err;
+
+		phy.dev = dev;
+		phy.id = fdtdec_get_uint(blob, args.node, "reg", -1);
+
+		ret = generic_phy_power_on(&phy);
+		if (ret) {
+			debug("unable to power on the phy\n");
+			goto clk_err;
+		}
+
+		ret = generic_phy_init(&phy);
+		if (ret) {
+			debug("failed to init usb phy\n");
+			goto phy_power_err;
+		}
+	}
+
+	/* Parse and store data needed for gadget */
+	stm32mp_otg_data.regs_otg = fdtdec_get_addr(blob, node, "reg");
+	if (stm32mp_otg_data.regs_otg == FDT_ADDR_T_NONE) {
+		debug("usbotg: can't get base address\n");
+		ret = -ENODATA;
+		goto phy_init_err;
+	}
+
+	stm32mp_otg_data.rx_fifo_sz = fdtdec_get_int(blob, node,
+						     "g-rx-fifo-size", 0);
+	stm32mp_otg_data.np_tx_fifo_sz = fdtdec_get_int(blob, node,
+							"g-np-tx-fifo-size", 0);
+	stm32mp_otg_data.tx_fifo_sz = fdtdec_get_int(blob, node,
+						     "g-tx-fifo-size", 0);
+	/* Enable voltage level detector */
+	if (!(fdtdec_parse_phandle_with_args(blob, node, "usb33d-supply",
+					     NULL, 0, 0, &args))) {
+		if (!uclass_get_device_by_of_offset(UCLASS_REGULATOR,
+						    args.node, &dev)) {
+			ret = regulator_set_enable(dev, true);
+			if (ret) {
+				debug("Failed to enable usb33d\n");
+				goto phy_init_err;
+			}
+		}
+	}
+		/* Enable vbus sensing */
+	setbits_le32(stm32mp_otg_data.regs_otg + STM32MP_GGPIO,
+		     STM32MP_GGPIO_VBUS_SENSING);
+
+	return dwc2_udc_probe(&stm32mp_otg_data);
+
+phy_init_err:
+	generic_phy_exit(&phy);
+
+phy_power_err:
+	generic_phy_power_off(&phy);
+
+clk_err:
+	clk_disable(&clk);
+
+	return ret;
+}
+
+int board_usb_cleanup(int index, enum usb_init_type init)
+{
+	/* Reset usbotg */
+	reset_assert(&usbotg_reset);
+	udelay(2);
+	reset_deassert(&usbotg_reset);
+
+	return 0;
+}
+
 int board_late_init(void)
 {
 	return 0;