extcon: usbc-tusb320: Add support for mode setting and reset

[linux-2.6-microblaze.git] / drivers / extcon / extcon-usbc-tusb320.c

diff --git a/drivers/extcon/extcon-usbc-tusb320.c b/drivers/extcon/extcon-usbc-tusb320.c
index 805af73..1ed1dfe 100644 (file)
--- a/drivers/extcon/extcon-usbc-tusb320.c
+++ b/drivers/extcon/extcon-usbc-tusb320.c
@@ -19,15 +19,32 @@
 #define TUSB320_REG9_ATTACHED_STATE_MASK       0x3
 #define TUSB320_REG9_CABLE_DIRECTION           BIT(5)
 #define TUSB320_REG9_INTERRUPT_STATUS          BIT(4)
-#define TUSB320_ATTACHED_STATE_NONE            0x0
-#define TUSB320_ATTACHED_STATE_DFP             0x1
-#define TUSB320_ATTACHED_STATE_UFP             0x2
-#define TUSB320_ATTACHED_STATE_ACC             0x3
+
+#define TUSB320_REGA                           0xa
+#define TUSB320_REGA_I2C_SOFT_RESET            BIT(3)
+#define TUSB320_REGA_MODE_SELECT_SHIFT         4
+#define TUSB320_REGA_MODE_SELECT_MASK          0x3
+
+enum tusb320_attached_state {
+       TUSB320_ATTACHED_STATE_NONE,
+       TUSB320_ATTACHED_STATE_DFP,
+       TUSB320_ATTACHED_STATE_UFP,
+       TUSB320_ATTACHED_STATE_ACC,
+};
+
+enum tusb320_mode {
+       TUSB320_MODE_PORT,
+       TUSB320_MODE_UFP,
+       TUSB320_MODE_DFP,
+       TUSB320_MODE_DRP,
+};
 
 struct tusb320_priv {
        struct device *dev;
        struct regmap *regmap;
        struct extcon_dev *edev;
+
+       enum tusb320_attached_state state;
 };
 
 static const char * const tusb_attached_states[] = {
@@ -62,6 +79,53 @@ static int tusb320_check_signature(struct tusb320_priv *priv)
        return 0;
 }
 
+static int tusb320_set_mode(struct tusb320_priv *priv, enum tusb320_mode mode)
+{
+       int ret;
+
+       /* Mode cannot be changed while cable is attached */
+       if (priv->state != TUSB320_ATTACHED_STATE_NONE)
+               return -EBUSY;
+
+       /* Write mode */
+       ret = regmap_write_bits(priv->regmap, TUSB320_REGA,
+               TUSB320_REGA_MODE_SELECT_MASK << TUSB320_REGA_MODE_SELECT_SHIFT,
+               mode << TUSB320_REGA_MODE_SELECT_SHIFT);
+       if (ret) {
+               dev_err(priv->dev, "failed to write mode: %d\n", ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int tusb320_reset(struct tusb320_priv *priv)
+{
+       int ret;
+
+       /* Set mode to default (follow PORT pin) */
+       ret = tusb320_set_mode(priv, TUSB320_MODE_PORT);
+       if (ret && ret != -EBUSY) {
+               dev_err(priv->dev,
+                       "failed to set mode to PORT: %d\n", ret);
+               return ret;
+       }
+
+       /* Perform soft reset */
+       ret = regmap_write_bits(priv->regmap, TUSB320_REGA,
+                       TUSB320_REGA_I2C_SOFT_RESET, 1);
+       if (ret) {
+               dev_err(priv->dev,
+                       "failed to write soft reset bit: %d\n", ret);
+               return ret;
+       }
+
+       /* Wait for chip to go through reset */
+       msleep(95);
+
+       return 0;
+}
+
 static irqreturn_t tusb320_irq_handler(int irq, void *dev_id)
 {
        struct tusb320_priv *priv = dev_id;
@@ -96,6 +160,8 @@ static irqreturn_t tusb320_irq_handler(int irq, void *dev_id)
        extcon_sync(priv->edev, EXTCON_USB);
        extcon_sync(priv->edev, EXTCON_USB_HOST);
 
+       priv->state = state;
+
        regmap_write(priv->regmap, TUSB320_REG9, reg);
 
        return IRQ_HANDLED;
@@ -145,6 +211,17 @@ static int tusb320_extcon_probe(struct i2c_client *client,
        /* update initial state */
        tusb320_irq_handler(client->irq, priv);
 
+       /* Reset chip to its default state */
+       ret = tusb320_reset(priv);
+       if (ret)
+               dev_warn(priv->dev, "failed to reset chip: %d\n", ret);
+       else
+               /*
+                * State and polarity might change after a reset, so update
+                * them again and make sure the interrupt status bit is cleared.
+                */
+               tusb320_irq_handler(client->irq, priv);
+
        ret = devm_request_threaded_irq(priv->dev, client->irq, NULL,
                                        tusb320_irq_handler,
                                        IRQF_TRIGGER_FALLING | IRQF_ONESHOT,