extcon: palmas: Support GPIO based USB ID detection

Some palmas based chip variants do not have OTG based ID logic.
For these variants we rely on GPIO based USB ID detection.

These chips do have VBUS comparator for VBUS detection so we
continue to use the old way of detecting VBUS.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

diff --git a/Documentation/devicetree/bindings/extcon/extcon-palmas.txt b/Documentation/devicetree/bindings/extcon/extcon-palmas.txt
index 45414bbcd9455b13620e9923f0dec048995c82cb..f72889563ca8da18fc9f3b56682982a83940a62f 100644 (file)
--- a/Documentation/devicetree/bindings/extcon/extcon-palmas.txt
+++ b/Documentation/devicetree/bindings/extcon/extcon-palmas.txt
@@ -10,8 +10,11 @@ Required Properties:
 
 Optional Properties:
  - ti,wakeup : To enable the wakeup comparator in probe
- - ti,enable-id-detection: Perform ID detection.
+ - ti,enable-id-detection: Perform ID detection using OTG core.
+ - ti,enable-gpio-id-detection: Perform ID detection using GPIO.
  - ti,enable-vbus-detection: Perform VBUS detection.
+ - id-gpio: gpio for GPIO ID detection. See gpio binding. Only required
+           if ti,enable-gpio-id-detection is present.
 
 palmas-usb {
        compatible = "ti,twl6035-usb", "ti,palmas-usb";

diff --git a/drivers/extcon/extcon-palmas.c b/drivers/extcon/extcon-palmas.c
index ae73950903c537586e9e381499eb181afdb8619f..933a0eb9991d0d9107b32ec4a3cf751aee199b71 100644 (file)
--- a/drivers/extcon/extcon-palmas.c
+++ b/drivers/extcon/extcon-palmas.c
@@ -28,6 +28,9 @@
 #include <linux/mfd/palmas.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+
+#define USB_GPIO_DEBOUNCE_MS   20      /* ms */
 
 static const char *palmas_extcon_cable[] = {
        [0] = "USB",
@@ -118,19 +121,52 @@ static irqreturn_t palmas_id_irq_handler(int irq, void *_palmas_usb)
        return IRQ_HANDLED;
 }
 
+static void palmas_gpio_id_detect(struct palmas_usb *palmas_usb)
+{
+       int id;
+
+       if (!palmas_usb->id_gpiod)
+               return;
+
+       id = gpiod_get_value_cansleep(palmas_usb->id_gpiod);
+
+       if (id) {
+               extcon_set_cable_state(palmas_usb->edev, "USB-HOST", false);
+               dev_info(palmas_usb->dev, "USB-HOST cable is detached\n");
+       } else {
+               extcon_set_cable_state(palmas_usb->edev, "USB-HOST", true);
+               dev_info(palmas_usb->dev, "USB-HOST cable is attached\n");
+       }
+}
+
+static irqreturn_t palmas_gpio_id_irq_handler(int irq, void *_palmas_usb)
+{
+       struct palmas_usb *palmas_usb = _palmas_usb;
+
+       if (palmas_usb->sw_debounce_ms)
+               mdelay(palmas_usb->sw_debounce_ms);
+
+       palmas_gpio_id_detect(palmas_usb);
+
+       return IRQ_HANDLED;
+}
+
 static void palmas_enable_irq(struct palmas_usb *palmas_usb)
 {
        palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
                PALMAS_USB_VBUS_CTRL_SET,
                PALMAS_USB_VBUS_CTRL_SET_VBUS_ACT_COMP);
 
-       palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
-               PALMAS_USB_ID_CTRL_SET, PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);
+       if (palmas_usb->enable_id_detection) {
+               palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+                            PALMAS_USB_ID_CTRL_SET,
+                            PALMAS_USB_ID_CTRL_SET_ID_ACT_COMP);
 
-       palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
-               PALMAS_USB_ID_INT_EN_HI_SET,
-               PALMAS_USB_ID_INT_EN_HI_SET_ID_GND |
-               PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
+               palmas_write(palmas_usb->palmas, PALMAS_USB_OTG_BASE,
+                            PALMAS_USB_ID_INT_EN_HI_SET,
+                            PALMAS_USB_ID_INT_EN_HI_SET_ID_GND |
+                            PALMAS_USB_ID_INT_EN_HI_SET_ID_FLOAT);
+       }
 
        if (palmas_usb->enable_vbus_detection)
                palmas_vbus_irq_handler(palmas_usb->vbus_irq, palmas_usb);
@@ -160,29 +196,45 @@ static int palmas_usb_probe(struct platform_device *pdev)
                                                "ti,enable-id-detection");
                palmas_usb->enable_vbus_detection = of_property_read_bool(node,
                                                "ti,enable-vbus-detection");
+               palmas_usb->enable_gpio_id_detection = of_property_read_bool(node,
+                                               "ti,enable-gpio-id-detection");
        } else {
                palmas_usb->wakeup = true;
                palmas_usb->enable_id_detection = true;
                palmas_usb->enable_vbus_detection = true;
+               /* gpio_id_detection not yet suppored for legacy boot */
 
                if (pdata)
                        palmas_usb->wakeup = pdata->wakeup;
        }
 
+       if (palmas_usb->enable_id_detection &&
+           palmas_usb->enable_gpio_id_detection) {
+               dev_err(&pdev->dev,
+                       "can't enable id and gpio-id detection together\n");
+               return -EINVAL;
+       }
+
+       if (palmas_usb->enable_gpio_id_detection) {
+               u32 debounce = USB_GPIO_DEBOUNCE_MS;
+
+               palmas_usb->id_gpiod = devm_gpiod_get(&pdev->dev, "id");
+               if (IS_ERR(palmas_usb->id_gpiod)) {
+                       dev_err(&pdev->dev, "failed to get id gpio\n");
+                       return -ENODEV;
+               }
+
+               status = gpiod_set_debounce(palmas_usb->id_gpiod,
+                                           debounce * 1000);
+               if (status < 0)
+                       palmas_usb->sw_debounce_ms = debounce;
+       }
+
        palmas->usb = palmas_usb;
        palmas_usb->palmas = palmas;
 
        palmas_usb->dev  = &pdev->dev;
 
-       palmas_usb->id_otg_irq = regmap_irq_get_virq(palmas->irq_data,
-                                               PALMAS_ID_OTG_IRQ);
-       palmas_usb->id_irq = regmap_irq_get_virq(palmas->irq_data,
-                                               PALMAS_ID_IRQ);
-       palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
-                                               PALMAS_VBUS_OTG_IRQ);
-       palmas_usb->vbus_irq = regmap_irq_get_virq(palmas->irq_data,
-                                               PALMAS_VBUS_IRQ);
-
        palmas_usb_wakeup(palmas, palmas_usb->wakeup);
 
        platform_set_drvdata(pdev, palmas_usb);
@@ -204,6 +256,10 @@ static int palmas_usb_probe(struct platform_device *pdev)
        }
 
        if (palmas_usb->enable_id_detection) {
+               palmas_usb->id_otg_irq = regmap_irq_get_virq(palmas->irq_data,
+                                                            PALMAS_ID_OTG_IRQ);
+               palmas_usb->id_irq = regmap_irq_get_virq(palmas->irq_data,
+                                                        PALMAS_ID_IRQ);
                status = devm_request_threaded_irq(palmas_usb->dev,
                                palmas_usb->id_irq,
                                NULL, palmas_id_irq_handler,
@@ -216,9 +272,33 @@ static int palmas_usb_probe(struct platform_device *pdev)
                        kfree(palmas_usb->edev->name);
                        return status;
                }
+       } else if (palmas_usb->enable_gpio_id_detection) {
+               palmas_usb->gpio_id_irq = gpiod_to_irq(palmas_usb->id_gpiod);
+               if (palmas_usb->gpio_id_irq < 0) {
+                       dev_err(&pdev->dev, "failed to get id irq\n");
+                       return palmas_usb->gpio_id_irq;
+               }
+               status = devm_request_threaded_irq(&pdev->dev,
+                                                  palmas_usb->gpio_id_irq,
+                                                  NULL,
+                                                  palmas_gpio_id_irq_handler,
+                                                  IRQF_TRIGGER_RISING |
+                                                  IRQF_TRIGGER_FALLING |
+                                                  IRQF_ONESHOT,
+                                                  "palmas_usb_id",
+                                                  palmas_usb);
+               if (status < 0) {
+                       dev_err(&pdev->dev,
+                               "failed to request handler for id irq\n");
+                       return status;
+               }
        }
 
        if (palmas_usb->enable_vbus_detection) {
+               palmas_usb->vbus_otg_irq = regmap_irq_get_virq(palmas->irq_data,
+                                                      PALMAS_VBUS_OTG_IRQ);
+               palmas_usb->vbus_irq = regmap_irq_get_virq(palmas->irq_data,
+                                                          PALMAS_VBUS_IRQ);
                status = devm_request_threaded_irq(palmas_usb->dev,
                                palmas_usb->vbus_irq, NULL,
                                palmas_vbus_irq_handler,
@@ -234,6 +314,8 @@ static int palmas_usb_probe(struct platform_device *pdev)
        }
 
        palmas_enable_irq(palmas_usb);
+       /* perform initial detection */
+       palmas_gpio_id_detect(palmas_usb);
        device_set_wakeup_capable(&pdev->dev, true);
        return 0;
 }
@@ -257,6 +339,8 @@ static int palmas_usb_suspend(struct device *dev)
                        enable_irq_wake(palmas_usb->vbus_irq);
                if (palmas_usb->enable_id_detection)
                        enable_irq_wake(palmas_usb->id_irq);
+               if (palmas_usb->enable_gpio_id_detection)
+                       enable_irq_wake(palmas_usb->gpio_id_irq);
        }
        return 0;
 }
@@ -270,6 +354,8 @@ static int palmas_usb_resume(struct device *dev)
                        disable_irq_wake(palmas_usb->vbus_irq);
                if (palmas_usb->enable_id_detection)
                        disable_irq_wake(palmas_usb->id_irq);
+               if (palmas_usb->enable_gpio_id_detection)
+                       disable_irq_wake(palmas_usb->gpio_id_irq);
        }
        return 0;
 };

diff --git a/include/linux/mfd/palmas.h b/include/linux/mfd/palmas.h
index e8cf4c2ac196466a95f42f2286af771485ddec34..337fded71aa937bde1c8f4ee416e6be4a60ef20a 100644 (file)
--- a/include/linux/mfd/palmas.h
+++ b/include/linux/mfd/palmas.h
@@ -21,6 +21,7 @@
 #include <linux/regmap.h>
 #include <linux/regulator/driver.h>
 #include <linux/extcon.h>
+#include <linux/of_gpio.h>
 #include <linux/usb/phy_companion.h>
 
 #define PALMAS_NUM_CLIENTS             3
@@ -552,10 +553,15 @@ struct palmas_usb {
        int vbus_otg_irq;
        int vbus_irq;
 
+       int gpio_id_irq;
+       struct gpio_desc *id_gpiod;
+       int sw_debounce_ms;
+
        enum palmas_usb_state linkstat;
        int wakeup;
        bool enable_vbus_detection;
        bool enable_id_detection;
+       bool enable_gpio_id_detection;
 };
 
 #define comparator_to_palmas(x) container_of((x), struct palmas_usb, comparator)