stm32mp1: add stusb1600 support for DK1 and DK2 board

The DK1 and DK2 boards use the USB Type-C controller STUSB1600.
This patch updates:
- the device tree to add the I2C node in the DT
- the board stm32mp1 to probe this I2C device and use this controller
  to check cable detection.
- the DWC2 driver to support a new dt property
  "u-boot,force-b-session-valid" which forces B session and
  device mode; it is a workaround because the VBUS sensing and
  ID detection isn't available with stusb1600.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>

1 files changed, 56 insertions, 0 deletions

diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index b369b7a54b6..76917b022ed 100644
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -9,15 +9,18 @@
 #include <dm.h>
 #include <g_dnl.h>
 #include <generic-phy.h>
+#include <i2c.h>
 #include <led.h>
 #include <misc.h>
 #include <phy.h>
 #include <reset.h>
 #include <syscon.h>
+#include <usb.h>
 #include <asm/io.h>
 #include <asm/gpio.h>
 #include <asm/arch/stm32.h>
 #include <power/regulator.h>
+#include <usb/dwc2_udc.h>
 
 /* SYSCFG registers */
 #define SYSCFG_BOOTR		0x00
@@ -151,11 +154,64 @@ static void board_key_check(void)
 
 #if defined(CONFIG_USB_GADGET) && defined(CONFIG_USB_GADGET_DWC2_OTG)
 
+/* STMicroelectronics STUSB1600 Type-C controller */
+#define STUSB1600_CC_CONNECTION_STATUS		0x0E
+
+/* STUSB1600_CC_CONNECTION_STATUS bitfields */
+#define STUSB1600_CC_ATTACH			BIT(0)
+
+static int stusb1600_init(struct udevice **dev_stusb1600)
+{
+	ofnode node;
+	struct udevice *dev, *bus;
+	int ret;
+	u32 chip_addr;
+
+	*dev_stusb1600 = NULL;
+
+	/* if node stusb1600 is present, means DK1 or DK2 board */
+	node = ofnode_by_compatible(ofnode_null(), "st,stusb1600");
+	if (!ofnode_valid(node))
+		return -ENODEV;
+
+	ret = ofnode_read_u32(node, "reg", &chip_addr);
+	if (ret)
+		return -EINVAL;
+
+	ret = uclass_get_device_by_ofnode(UCLASS_I2C, ofnode_get_parent(node),
+					  &bus);
+	if (ret) {
+		printf("bus for stusb1600 not found\n");
+		return -ENODEV;
+	}
+
+	ret = dm_i2c_probe(bus, chip_addr, 0, &dev);
+	if (!ret)
+		*dev_stusb1600 = dev;
+
+	return ret;
+}
+
+static int stusb1600_cable_connected(struct udevice *dev)
+{
+	u8 status;
+
+	if (dm_i2c_read(dev, STUSB1600_CC_CONNECTION_STATUS, &status, 1))
+		return 0;
+
+	return status & STUSB1600_CC_ATTACH;
+}
+
+#include <usb/dwc2_udc.h>
 int g_dnl_board_usb_cable_connected(void)
 {
+	struct udevice *stusb1600;
 	struct udevice *dwc2_udc_otg;
 	int ret;
 
+	if (!stusb1600_init(&stusb1600))
+		return stusb1600_cable_connected(stusb1600);
+
 	ret = uclass_get_device_by_driver(UCLASS_USB_GADGET_GENERIC,
 					  DM_GET_DRIVER(dwc2_udc_otg),
 					  &dwc2_udc_otg);