extcon: usbc-tusb320: add accessory detection support

The TUSB320 can detect the following types of accessory:

  - Audio Accessory
  - Audio Accessory with charge-thru
  - Debug Accessory (DFP)
  - Debug Accessory (UFP)

Moreover, the typec subsystem can be informed of this through the
typec_set_mode() function. The information will be propagated to any
linked typec muxes. Add the necessary support to the driver.

Note that for the Debug Accessory modes, an educated guess was made that
for the USB data role, DFP implies HOST and UFP implies DEVICE. But this
might want to be made configurable at a later date.

Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

diff --git a/drivers/extcon/extcon-usbc-tusb320.c b/drivers/extcon/extcon-usbc-tusb320.c
index 10dff1c..882d1f4 100644 (file)
--- a/drivers/extcon/extcon-usbc-tusb320.c
+++ b/drivers/extcon/extcon-usbc-tusb320.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/regmap.h>
 #include <linux/usb/typec.h>
+#include <linux/usb/typec_altmode.h>
 
 #define TUSB320_REG8                           0x8
 #define TUSB320_REG8_CURRENT_MODE_ADVERTISE    GENMASK(7, 6)
@@ -26,16 +27,16 @@
 #define TUSB320_REG8_CURRENT_MODE_DETECT_MED   0x1
 #define TUSB320_REG8_CURRENT_MODE_DETECT_ACC   0x2
 #define TUSB320_REG8_CURRENT_MODE_DETECT_HI    0x3
-#define TUSB320_REG8_ACCESSORY_CONNECTED       GENMASK(3, 2)
+#define TUSB320_REG8_ACCESSORY_CONNECTED       GENMASK(3, 1)
 #define TUSB320_REG8_ACCESSORY_CONNECTED_NONE  0x0
 #define TUSB320_REG8_ACCESSORY_CONNECTED_AUDIO 0x4
-#define TUSB320_REG8_ACCESSORY_CONNECTED_ACC   0x5
-#define TUSB320_REG8_ACCESSORY_CONNECTED_DEBUG 0x6
+#define TUSB320_REG8_ACCESSORY_CONNECTED_ACHRG 0x5
+#define TUSB320_REG8_ACCESSORY_CONNECTED_DBGDFP        0x6
+#define TUSB320_REG8_ACCESSORY_CONNECTED_DBGUFP        0x7
 #define TUSB320_REG8_ACTIVE_CABLE_DETECTION    BIT(0)
 
 #define TUSB320_REG9                           0x9
-#define TUSB320_REG9_ATTACHED_STATE_SHIFT      6
-#define TUSB320_REG9_ATTACHED_STATE_MASK       0x3
+#define TUSB320_REG9_ATTACHED_STATE            GENMASK(7, 6)
 #define TUSB320_REG9_CABLE_DIRECTION           BIT(5)
 #define TUSB320_REG9_INTERRUPT_STATUS          BIT(4)
 
@@ -250,8 +251,7 @@ static void tusb320_extcon_irq_handler(struct tusb320_priv *priv, u8 reg)
 {
        int state, polarity;
 
-       state = (reg >> TUSB320_REG9_ATTACHED_STATE_SHIFT) &
-               TUSB320_REG9_ATTACHED_STATE_MASK;
+       state = FIELD_GET(TUSB320_REG9_ATTACHED_STATE, reg);
        polarity = !!(reg & TUSB320_REG9_CABLE_DIRECTION);
 
        dev_dbg(priv->dev, "attached state: %s, polarity: %d\n",
@@ -277,32 +277,78 @@ static void tusb320_typec_irq_handler(struct tusb320_priv *priv, u8 reg9)
 {
        struct typec_port *port = priv->port;
        struct device *dev = priv->dev;
-       u8 mode, role, state;
+       int typec_mode;
+       enum typec_role pwr_role;
+       enum typec_data_role data_role;
+       u8 state, mode, accessory;
        int ret, reg8;
        bool ori;
 
+       ret = regmap_read(priv->regmap, TUSB320_REG8, &reg8);
+       if (ret) {
+               dev_err(dev, "error during reg8 i2c read, ret=%d!\n", ret);
+               return;
+       }
+
        ori = reg9 & TUSB320_REG9_CABLE_DIRECTION;
        typec_set_orientation(port, ori ? TYPEC_ORIENTATION_REVERSE :
                                          TYPEC_ORIENTATION_NORMAL);
 
-       state = (reg9 >> TUSB320_REG9_ATTACHED_STATE_SHIFT) &
-               TUSB320_REG9_ATTACHED_STATE_MASK;
-       if (state == TUSB320_ATTACHED_STATE_DFP)
-               role = TYPEC_SOURCE;
-       else
-               role = TYPEC_SINK;
+       state = FIELD_GET(TUSB320_REG9_ATTACHED_STATE, reg9);
+       accessory = FIELD_GET(TUSB320_REG8_ACCESSORY_CONNECTED, reg8);
+
+       switch (state) {
+       case TUSB320_ATTACHED_STATE_DFP:
+               typec_mode = TYPEC_MODE_USB2;
+               pwr_role = TYPEC_SOURCE;
+               data_role = TYPEC_HOST;
+               break;
+       case TUSB320_ATTACHED_STATE_UFP:
+               typec_mode = TYPEC_MODE_USB2;
+               pwr_role = TYPEC_SINK;
+               data_role = TYPEC_DEVICE;
+               break;
+       case TUSB320_ATTACHED_STATE_ACC:
+               /*
+                * Accessory detected. For debug accessories, just make some
+                * qualified guesses as to the role for lack of a better option.
+                */
+               if (accessory == TUSB320_REG8_ACCESSORY_CONNECTED_AUDIO ||
+                   accessory == TUSB320_REG8_ACCESSORY_CONNECTED_ACHRG) {
+                       typec_mode = TYPEC_MODE_AUDIO;
+                       pwr_role = TYPEC_SINK;
+                       data_role = TYPEC_DEVICE;
+                       break;
+               } else if (accessory ==
+                          TUSB320_REG8_ACCESSORY_CONNECTED_DBGDFP) {
+                       typec_mode = TYPEC_MODE_DEBUG;
+                       pwr_role = TYPEC_SOURCE;
+                       data_role = TYPEC_HOST;
+                       break;
+               } else if (accessory ==
+                          TUSB320_REG8_ACCESSORY_CONNECTED_DBGUFP) {
+                       typec_mode = TYPEC_MODE_DEBUG;
+                       pwr_role = TYPEC_SINK;
+                       data_role = TYPEC_DEVICE;
+                       break;
+               }
 
-       typec_set_vconn_role(port, role);
-       typec_set_pwr_role(port, role);
-       typec_set_data_role(port, role == TYPEC_SOURCE ?
-                                 TYPEC_HOST : TYPEC_DEVICE);
+               dev_warn(priv->dev, "unexpected ACCESSORY_CONNECTED state %d\n",
+                        accessory);
 
-       ret = regmap_read(priv->regmap, TUSB320_REG8, &reg8);
-       if (ret) {
-               dev_err(dev, "error during reg8 i2c read, ret=%d!\n", ret);
-               return;
+               fallthrough;
+       default:
+               typec_mode = TYPEC_MODE_USB2;
+               pwr_role = TYPEC_SINK;
+               data_role = TYPEC_DEVICE;
+               break;
        }
 
+       typec_set_vconn_role(port, pwr_role);
+       typec_set_pwr_role(port, pwr_role);
+       typec_set_data_role(port, data_role);
+       typec_set_mode(port, typec_mode);
+
        mode = FIELD_GET(TUSB320_REG8_CURRENT_MODE_DETECT, reg8);
        if (mode == TUSB320_REG8_CURRENT_MODE_DETECT_DEF)
                typec_set_pwr_opmode(port, TYPEC_PWR_MODE_USB);