[PATCH 6/6] phy: twl4030-usb: add extcon to report cable connections.

[NeilBrown <neil@brown.name>]

From: NeilBrown <neilb@suse.de>

Signed-off-by: NeilBrown <neilb@suse.de>
---
 drivers/phy/phy-twl4030-usb.c |   67 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/drivers/phy/phy-twl4030-usb.c b/drivers/phy/phy-twl4030-usb.c
index 1d6f3e70193e..c42153d43ec2 100644
--- a/drivers/phy/phy-twl4030-usb.c
+++ b/drivers/phy/phy-twl4030-usb.c
@@ -40,6 +40,7 @@
 #include <linux/regulator/consumer.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/extcon.h>
 
 /* Register defines */
 
@@ -173,6 +174,9 @@ struct twl4030_usb {
 	enum omap_musb_vbus_id_status linkstat;
 	bool			vbus_supplied;
 
+	/* cable connection */
+	struct extcon_dev	edev;
+
 	struct delayed_work	id_workaround_work;
 };
 
@@ -592,6 +596,54 @@ static ssize_t twl4030_usb_id_show(struct device *dev,
 }
 static DEVICE_ATTR(id, 0444, twl4030_usb_id_show, NULL);
 
+static const char *usb_cables[] = {
+	"USB", /* id is floating */
+	"Charger-downstream", /* id is floating and D+ shorted to D- */
+	"USB-Host", /* id is ground */
+	"USB-ACA", /* "Accessory Charger Adapter" id is something else */
+	NULL
+};
+enum {
+	TWL_CABLE_USB,
+	TWL_CABLE_CHARGER,	/* Not used - twl4030 can detect charger,
+				 * but driver cannot yet */
+	TWL_CABLE_OTG,
+	TWL_CABLE_ACA,
+};
+static u32 all_exclusive[] =  {0xFFFFFFFF, 0};
+
+static void twl4030_usb_report_cable(struct twl4030_usb *twl)
+{
+	enum twl4030_id_status sts;
+
+	if (!cable_present(twl->linkstat)) {
+		extcon_set_state(&twl->edev, 0);
+		return;
+	}
+
+	sts = twl4030_get_id(twl);
+
+	switch (sts) {
+	case TWL4030_FLOATING: /* USB downstream */
+		extcon_update_state(&twl->edev,
+				    1<<TWL_CABLE_USB,
+				    1<<TWL_CABLE_USB);
+		break;
+	case TWL4030_GROUND: /* USB host */
+		extcon_update_state(&twl->edev,
+				    1<<TWL_CABLE_OTG,
+				    1<<TWL_CABLE_OTG);
+		break;
+	default: /* Some resistor */
+		extcon_update_state(&twl->edev,
+				    1<<TWL_CABLE_ACA,
+				    1<<TWL_CABLE_ACA);
+		/* An ACA should set port to 'host' mode */
+		twl->linkstat = OMAP_MUSB_ID_GROUND;
+		break;
+	}
+}
+
 static irqreturn_t twl4030_usb_irq(int irq, void *_twl)
 {
 	struct twl4030_usb *twl = _twl;
@@ -628,6 +680,7 @@ static irqreturn_t twl4030_usb_irq(int irq, void *_twl)
 			pm_runtime_put_autosuspend(twl->dev);
 		}
 		omap_musb_mailbox(status);
+		twl4030_usb_report_cable(twl);
 	}
 
 	/* don't schedule during sleep - irq works right then */
@@ -766,6 +819,20 @@ static int twl4030_usb_probe(struct platform_device *pdev)
 	}
 	usb_add_phy_dev(&twl->phy);
 
+	twl->edev.name = devm_kasprintf(twl->dev, GFP_KERNEL, "%s-usb",
+					dev_name(twl->dev->parent));
+	twl->edev.supported_cable = usb_cables;
+	twl->edev.mutually_exclusive = all_exclusive;
+	twl->edev.print_name = NULL; /* why would you change this? */
+	twl->edev.print_state = NULL; /* probably want to change this */
+
+	twl->edev.dev.parent = &pdev->dev;
+	err = extcon_dev_register(&twl->edev);
+	if (err) {
+		dev_err(&pdev->dev, "register extcon failed\n");
+		return err;
+	}
+
 	platform_set_drvdata(pdev, twl);
 	if (device_create_file(&pdev->dev, &dev_attr_vbus))
 		dev_warn(&pdev->dev, "could not create sysfs file\n");