usb: dwc3: pci: add quirk for Baytrails

On some BYT platforms the USB2 PHY needs to be put into
operational mode by the controller driver with GPIOs
controlling the PHYs reset and cs signals.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/dwc3-pci.c

@@ -21,6 +21,8 @@
 #include <linux/slab.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/acpi.h>
 
 #include "platform_data.h"
 
@@ -31,6 +33,15 @@
 #define PCI_DEVICE_ID_INTEL_SPTLP	0x9d30
 #define PCI_DEVICE_ID_INTEL_SPTH	0xa130
 
+static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
+static const struct acpi_gpio_params cs_gpios = { 1, 0, false };
+
+static const struct acpi_gpio_mapping acpi_dwc3_byt_gpios[] = {
+	{ "reset-gpios", &reset_gpios, 1 },
+	{ "cs-gpios", &cs_gpios, 1 },
+	{ },
+};
+
 static int dwc3_pci_quirks(struct pci_dev *pdev)
 {
 	if (pdev->vendor == PCI_VENDOR_ID_AMD &&
@@ -65,6 +76,30 @@ static int dwc3_pci_quirks(struct pci_dev *pdev)
 						sizeof(pdata));
 	}
 
+	if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
+	    pdev->device == PCI_DEVICE_ID_INTEL_BYT) {
+		struct gpio_desc *gpio;
+
+		acpi_dev_add_driver_gpios(ACPI_COMPANION(&pdev->dev),
+					  acpi_dwc3_byt_gpios);
+
+		/* These GPIOs will turn on the USB2 PHY */
+		gpio = gpiod_get(&pdev->dev, "cs");
+		if (!IS_ERR(gpio)) {
+			gpiod_direction_output(gpio, 0);
+			gpiod_set_value_cansleep(gpio, 1);
+			gpiod_put(gpio);
+		}
+
+		gpio = gpiod_get(&pdev->dev, "reset");
+		if (!IS_ERR(gpio)) {
+			gpiod_direction_output(gpio, 0);
+			gpiod_set_value_cansleep(gpio, 1);
+			gpiod_put(gpio);
+			usleep_range(10000, 11000);
+		}
+	}
+
 	return 0;
 }
 
@@ -128,6 +163,7 @@ static int dwc3_pci_probe(struct pci_dev *pci,
 
 static void dwc3_pci_remove(struct pci_dev *pci)
 {
+	acpi_dev_remove_driver_gpios(ACPI_COMPANION(&pci->dev));
 	platform_device_unregister(pci_get_drvdata(pci));
 }