From: Seung-Woo Kim <sw0312.kim@samsung.com>
Date: Fri, 18 Aug 2023 06:34:10 +0000 (+0900)
Subject: usb: cdns3-starfive: Add extcon usb gadget state with always connected
X-Git-Tag: accepted/tizen/unified/riscv/20230821.094308~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=refs%2Fchanges%2F36%2F297436%2F2;p=platform%2Fkernel%2Flinux-starfive.git

usb: cdns3-starfive: Add extcon usb gadget state with always connected

Add extcon usb gadget state and set usb gadget state as connected.

The cdns3-starfive usb c port in visionfive2 board only has usb
d-/d+ lines and vbus and ground lines are used for power supply.
Because of the H/W limitation, it is not possible to detect usb
c port connected state.

In Tizen, deviced configures usb gadget functions only with the
usb connected state, so, to support usb gadget functionality,
the usb state should be set.

Change-Id: I3e3a25a726c7205b3d9a5fd96d8557562bfda81f
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
---

diff --git a/drivers/usb/cdns3/Kconfig b/drivers/usb/cdns3/Kconfig
index 0a514b591527..b139e66dfbf3 100644
--- a/drivers/usb/cdns3/Kconfig
+++ b/drivers/usb/cdns3/Kconfig
@@ -131,3 +131,14 @@ config USB_CDNSP_HOST
 	  standard XHCI driver.
 
 endif
+
+if USB_CDNS3_STARFIVE
+
+config USB_CDNS3_STARFIVE_EXTCON
+	bool "Extcon USB state support on Cadence USB3 of Starfive SoC"
+	depends on EXTCON
+	help
+	  Say Y here to enable external connector event of the StarFive SoC
+	  platforms that contain Cadence USB3 controller core.
+
+endif
diff --git a/drivers/usb/cdns3/cdns3-starfive.c b/drivers/usb/cdns3/cdns3-starfive.c
index a99f98f85235..55ae4ac53cbf 100644
--- a/drivers/usb/cdns3/cdns3-starfive.c
+++ b/drivers/usb/cdns3/cdns3-starfive.c
@@ -19,6 +19,9 @@
 #include <linux/regmap.h>
 #include <linux/reset.h>
 #include <linux/usb/otg.h>
+#if IS_ENABLED(CONFIG_USB_CDNS3_STARFIVE_EXTCON)
+#include <linux/extcon-provider.h>
+#endif
 #include "core.h"
 
 #define USB_STRAP_HOST			BIT(17)
@@ -55,6 +58,9 @@ struct cdns_starfive {
 	u32 stg_offset_328;
 	u32 stg_offset_500;
 	bool usb2_only;
+#if IS_ENABLED(CONFIG_USB_CDNS3_STARFIVE_EXTCON)
+	struct extcon_dev		*edev;
+#endif
 };
 
 static int cdns_mode_init(struct platform_device *pdev,
@@ -163,11 +169,21 @@ err_clk_init:
 	return ret;
 }
 
+#if IS_ENABLED(CONFIG_USB_CDNS3_STARFIVE_EXTCON)
+static const unsigned int supported_cable[] = {
+	EXTCON_USB,
+	EXTCON_NONE,
+};
+#endif
+
 static int cdns_starfive_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *node = pdev->dev.of_node;
 	struct cdns_starfive *data;
+#if IS_ENABLED(CONFIG_USB_CDNS3_STARFIVE_EXTCON)
+	struct extcon_dev *edev;
+#endif
 	unsigned int args[4];
 	const char *dr_mode;
 	int ret;
@@ -180,6 +196,21 @@ static int cdns_starfive_probe(struct platform_device *pdev)
 
 	data->dev = dev;
 
+#if IS_ENABLED(CONFIG_USB_CDNS3_STARFIVE_EXTCON)
+	edev = devm_extcon_dev_allocate(dev, supported_cable);
+	if (IS_ERR(edev))
+		return PTR_ERR(edev);
+
+	ret = devm_extcon_dev_register(dev, edev);
+	if (ret)
+		return ret;
+
+	/* Set starfive cdns3 usb always connected because of hw limitation */
+	extcon_set_state_sync(edev, EXTCON_USB, true);
+
+	data->edev = edev;
+#endif
+
 	data->stg_syscon = syscon_regmap_lookup_by_phandle_args(pdev->dev.of_node,
 		"starfive,stg-syscon", 4, args);