[PATCH 3/3] phy: starfive: jh7110-usb: Fix link configuration to controller

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka at siemens.com>

In order to connect the USB 2.0 PHY to its controller, we also need to
set "u0_pdrstn_split_sw_usbpipe_plugen" [1]. Some downstream U-Boot
versions did that, but upstream firmware does not, and the kernel must
not rely on such behavior anyway. Failing to set this left the USB
gadget port invisible to connected hosts behind.

Link: https://doc-en.rvspace.org/JH7110/TRM/JH7110_TRM/sys_syscon.html#sys_syscon__section_b3l_fqs_wsb [1]
Fixes: 16d3a71c20cf ("phy: starfive: Add JH7110 USB 2.0 PHY driver")
Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
---
 drivers/phy/starfive/phy-jh7110-usb.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/phy/starfive/phy-jh7110-usb.c b/drivers/phy/starfive/phy-jh7110-usb.c
index 633912f8a05d..67882bc4cebc 100644
--- a/drivers/phy/starfive/phy-jh7110-usb.c
+++ b/drivers/phy/starfive/phy-jh7110-usb.c
@@ -10,18 +10,24 @@
 #include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/io.h>
+#include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/usb/of.h>
 
 #define USB_125M_CLK_RATE		125000000
 #define USB_LS_KEEPALIVE_OFF		0x4
 #define USB_LS_KEEPALIVE_ENABLE		BIT(4)
 
+#define USB_PDRSTN_SPLIT		BIT(17)
+
 struct jh7110_usb2_phy {
 	struct phy *phy;
 	void __iomem *regs;
+	struct regmap *sys_syscon;
+	u32 sys_phy_connect;
 	struct clk *usb_125m_clk;
 	struct clk *app_125m;
 	enum phy_mode mode;
@@ -61,6 +67,10 @@ static int usb2_phy_set_mode(struct phy *_phy,
 		usb2_set_ls_keepalive(phy, (mode != PHY_MODE_USB_DEVICE));
 	}
 
+	/* Connect usb 2.0 phy mode */
+	regmap_update_bits(phy->sys_syscon, phy->sys_phy_connect,
+			   USB_PDRSTN_SPLIT, USB_PDRSTN_SPLIT);
+
 	return 0;
 }
 
@@ -101,6 +111,7 @@ static int jh7110_usb_phy_probe(struct platform_device *pdev)
 	struct jh7110_usb2_phy *phy;
 	struct device *dev = &pdev->dev;
 	struct phy_provider *phy_provider;
+	u32 args[1];
 
 	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
 	if (!phy)
@@ -129,6 +140,15 @@ static int jh7110_usb_phy_probe(struct platform_device *pdev)
 	phy_set_drvdata(phy->phy, phy);
 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 
+	phy->sys_syscon =
+		syscon_regmap_lookup_by_phandle_args(pdev->dev.of_node,
+						     "starfive,sys-syscon",
+						     1, args);
+	if (IS_ERR(phy->sys_syscon))
+		return dev_err_probe(dev, PTR_ERR(phy->phy),
+			"Failed to get sys-syscon\n");
+	phy->sys_phy_connect = args[0];
+
 	return PTR_ERR_OR_ZERO(phy_provider);
 }
 
-- 
2.43.0