[PATCH] extcon-intel-cht-wc: Don't reset USB data connection at probe

[Yauhen Kharuzhy]

Intel Cherry Trail Whiskey Cove extcon driver connect USB data lines to
PMIC at driver probing for further charger detection. This causes reset of
USB data sessions and removing all devices from bus. If system was
booted from Live CD or USB dongle, this makes system unusable.

Check if USB ID pin is floating and re-route data lines in this case
only, don't touch otherwise.

Signed-off-by: Yauhen Kharuzhy <jekhor@xxxxxxxxx>
---
 drivers/extcon/extcon-intel-cht-wc.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/extcon/extcon-intel-cht-wc.c b/drivers/extcon/extcon-intel-cht-wc.c
index 9d32150e68db..3ae573e93e6e 100644
--- a/drivers/extcon/extcon-intel-cht-wc.c
+++ b/drivers/extcon/extcon-intel-cht-wc.c
@@ -338,6 +338,7 @@ static int cht_wc_extcon_probe(struct platform_device *pdev)
 	struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
 	struct cht_wc_extcon_data *ext;
 	unsigned long mask = ~(CHT_WC_PWRSRC_VBUS | CHT_WC_PWRSRC_USBID_MASK);
+	int pwrsrc_sts, id;
 	int irq, ret;
 
 	irq = platform_get_irq(pdev, 0);
@@ -387,8 +388,19 @@ static int cht_wc_extcon_probe(struct platform_device *pdev)
 		goto disable_sw_control;
 	}
 
-	/* Route D+ and D- to PMIC for initial charger detection */
-	cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);
+	ret = regmap_read(ext->regmap, CHT_WC_PWRSRC_STS, &pwrsrc_sts);
+	if (ret) {
+		dev_err(ext->dev, "Error reading pwrsrc status: %d\n", ret);
+		goto disable_sw_control;
+	}
+
+	id = cht_wc_extcon_get_id(ext, pwrsrc_sts);
+
+	/* If no USB host or device connected, route D+ and D- to PMIC for
+	 * initial charger detection
+	 */
+	if (id == INTEL_USB_ID_FLOAT)
+		cht_wc_extcon_set_phymux(ext, MUX_SEL_PMIC);
 
 	/* Get initial state */
 	cht_wc_extcon_pwrsrc_event(ext);
-- 
2.23.0.rc0