linux-kernel - [PATCH v5 2/4] phy: da8xx-usb: Configure CFGCHIP2 to support OTG workaround

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Date:   Mon,  7 Nov 2016 14:05:06 +0100
From:   Alexandre Bailon <abailon@...libre.com>
To:     david@...hnology.com, b-liu@...com, balbi@...nel.org
Cc:     kishon@...com, khilman@...libre.com, linux-kernel@...r.kernel.org,
        linux-usb@...r.kernel.org, nsekhar@...com,
        Alexandre Bailon <abailon@...libre.com>
Subject: [PATCH v5 2/4] phy: da8xx-usb: Configure CFGCHIP2 to support OTG workaround

If we configure the da8xx OTG phy in OTG mode, neither device or host
mode will work. That is because the PHY is not able to detect and notify
the driver that value of ID pin changed.
To work despite this hardware limitation, the da8xx glue implement a
workaround.
But to work, the workaround require the VBUS sense and the session end
comparator to enabled.
Enable them if the phy is configured in OTG mode.

Signed-off-by: Alexandre Bailon <abailon@...libre.com>
---
 drivers/phy/phy-da8xx-usb.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/phy/phy-da8xx-usb.c b/drivers/phy/phy-da8xx-usb.c
index 32ae78c..089c13b 100644
--- a/drivers/phy/phy-da8xx-usb.c
+++ b/drivers/phy/phy-da8xx-usb.c
@@ -23,6 +23,8 @@
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 
+#define PHY_INIT_BITS	(CFGCHIP2_SESENDEN | CFGCHIP2_VBDTCTEN)
+
 struct da8xx_usb_phy {
 	struct phy_provider	*phy_provider;
 	struct phy		*usb11_phy;
@@ -207,6 +209,9 @@ static int da8xx_usb_phy_probe(struct platform_device *pdev)
 			dev_warn(dev, "Failed to create usb20 phy lookup\n");
 	}
 
+	regmap_write_bits(d_phy->regmap, CFGCHIP(2),
+			  PHY_INIT_BITS, PHY_INIT_BITS);
+
 	return 0;
 }
 
-- 
2.7.3