otgcontrol: add excton device registration (emulate OTG VID signal -> OTG driver)

drivers/misc/rm-otgcontrol/otgcontrol_dr_mode.c

@@ -1,17 +1,56 @@
 #include "otgcontrol_dr_mode.h"
 
-int otgcontrol_set_dr_mode(struct rm_otgcontrol_data *otgc_dta, int mode)
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+static const unsigned int usb_extcon_cable[] = {
+    EXTCON_USB_HOST,
+};
+
+int otgcontrol_init_extcon(struct rm_otgcontrol_data *otgc_data)
+{
+    int ret;
+
+    printk("%s: Allocating extcon device\n", __func__);
+    otgc_data->extcon_dev = devm_extcon_dev_allocate(otgc_data->dev, usb_extcon_cable);
+    if (IS_ERR(otgc_data->extcon_dev)) {
+        dev_err(otgc_data->dev, "%s: failed to allocate extcon device\n", __func__);
+        return -ENOMEM;
+    }
+
+    printk("%s: Registering extcon device\n", __func__);
+    ret = devm_extcon_dev_register(otgc_data->dev, otgc_data->extcon_dev);
+    if (ret < 0) {
+        dev_err(otgc_data->dev, "%s: Failed to register extcon device\n", __func__);
+        kfree(otgc_data->extcon_dev);
+        otgc_data->extcon_dev = NULL;
+        return ret;
+    }
+
+    return 0;
+}
+
+void otgcontrol_uninit_extcon(struct rm_otgcontrol_data *otgc_data)
+{
+    if (!IS_ERR(otgc_data->extcon_dev)) {
+        devm_extcon_dev_unregister(otgc_data->dev, otgc_data->extcon_dev);
+        kfree(otgc_data->extcon_dev);
+        otgc_data->extcon_dev = NULL;
+    }
+}
+
+int otgcontrol_set_dr_mode(struct rm_otgcontrol_data *otgc_data, int mode)
 {
     switch(mode)
     {
     case OTG1_DR_MODE__DEVICE:
         printk("%s: Switching OTG1 DR mode -> DEVICE\n", __func__);
-        /* Set ID pin emulation to LOW */
+        return extcon_set_state_sync(otgc_data->extcon_dev, EXTCON_USB_HOST, false);
         break;
 
     case OTG1_DR_MODE__HOST:
         printk("%s: Switching OTG1 DR mode -> HOST\n", __func__);
-        /* Set ID pin emulation to HIGH */
+        return extcon_set_state_sync(otgc_data->extcon_dev, EXTCON_USB_HOST, true);
         break;
 
     default:

drivers/misc/rm-otgcontrol/otgcontrol_dr_mode.h

@@ -6,6 +6,8 @@
 #define OTG1_DR_MODE__DEVICE                            0
 #define OTG1_DR_MODE__HOST                              1
 
+int otgcontrol_init_extcon(struct rm_otgcontrol_data *otgc_data);
+void otgcontrol_uninit_extcon(struct rm_otgcontrol_data *otgc_data);
 int otgcontrol_set_dr_mode(struct rm_otgcontrol_data *otgc_dta, int mode);
 int otgcontrol_get_dr_mode(struct rm_otgcontrol_data *otgc_data);
 

drivers/misc/rm-otgcontrol/otgcontrol_fsm.c

@@ -34,7 +34,7 @@ int otgcontrol_init_fsm(struct rm_otgcontrol_data *otgc_data)
     }
     return 0;
 }
-EXPORT_SYMBOL(otgcontrol_init_fsm);
+//EXPORT_SYMBOL(otgcontrol_init_fsm);
 
 int otgcontrol_set_controlmode(struct rm_otgcontrol_data *otgc_data, int mode)
 {
@@ -70,26 +70,27 @@ int otgcontrol_handleInput(struct rm_otgcontrol_data *otgc_data, int signal, voi
     {
     case OTG1_EVENT__CHALLENGE_REPLY_RECEIVED:
         printk("%s: CHALLENGE REPLY RECEIVED\n", __func__);
+        printk("%s: PLEASE IMPLEMENT THIS !\n", __func__);
         break;
 
     case OTG1_EVENT__MODE_CHANGE_REQUESTED:
         printk("%s: MODE CHANGE REQUESTED\n", __func__);
+        printk("%s: PLEASE IMPLEMENT THIS !\n", __func__);
         break;
 
     case OTG1_EVENT__ONEWIRE_GPIO_STATE_CHANGED:
         printk("%s: ONEWIRE GPIO STATE CHANGED\n", __func__);
+        printk("%s: PLEASE IMPLEMENT THIS !\n", __func__);
         break;
 
     case OTG1_EVENT__OTG_CHARGERMODE_CHANGE_REQUESTED:
         printk("%s: CHARGERMODE CHANGE REQUESTED\n", __func__);
+        printk("%s: PLEASE IMPLEMENT THIS !\n", __func__);
         break;
 
     case OTG1_EVENT__TIMEOUT:
         printk("%s: TIMEOUT\n", __func__);
-        break;
-
-    case OTG1_EVENT__VBUS_CHANGED:
-        printk("%s: VBUS CHANGED\n", __func__);
+        printk("%s: PLEASE IMPLEMENT SUPPORT FOR THIS !\n", __func__);
         break;
 
     default:
@@ -104,6 +105,6 @@ static int otgcontrol_start_onewire_authentication(struct rm_otgcontrol_data *ot
 {
     printk("%s: Enter\n", __func__);
 
-    printk("%s: PLEASE IMPLEMENT THIS\n", __func__);
+    printk("%s: PLEASE IMPLEMENT THIS !\n", __func__);
     return 0;
 }

drivers/misc/rm-otgcontrol/otgcontrol_main.c

@@ -12,6 +12,7 @@
 
 #include "otgcontrol_sysfs.h"
 #include "otgcontrol_fsm.h"
+#include "otgcontrol_dr_mode.h"
 
 /* Required Linux includes */
 #include <linux/kernel.h>
@@ -53,7 +54,11 @@ static int rm_otgcontrol_init(struct rm_otgcontrol_data *otgc_data)
 
     printk("%s: Initiating default ONEWIRE_AUTH state\n", __func__);
     ret = otgcontrol_init_fsm(otgc_data);
+    if (ret < 0)
+        return ret;
 
+    printk("%s: Initiating extcon device to control USB OTG dr mode\n", __func__);
+    ret = otgcontrol_init_extcon(otgc_data);
     return ret;
 }
 
@@ -148,7 +153,7 @@ static int rm_otgcontrol_probe(struct platform_device *pdev)
     printk("[---- SBA ----] %s: Setting otgc_data reference in pdev, and initiating\n", __func__);
     ret = rm_otgcontrol_init(otgc_data);
     if(ret < 0)
-        goto error_2;
+        goto error_3;
 
     platform_set_drvdata(pdev, otgc_data);
     return 0;
@@ -161,6 +166,13 @@ error_2:
     kfree(pdata);
     kfree(otgc_data);
     return ret;
+
+error_3:
+    otgcontrol_uninit_sysfs_nodes(otgc_data);
+    otgcontrol_uninit_extcon(otgc_data);
+    kfree(pdata);
+    kfree(otgc_data);
+    return ret;
 }
 
 static int rm_otgcontrol_remove(struct platform_device *pdev)
@@ -172,6 +184,9 @@ static int rm_otgcontrol_remove(struct platform_device *pdev)
     printk("%s: Un-initializing sysfs nodes\n", __func__);
     otgcontrol_uninit_sysfs_nodes(otgc_data);
 
+    printk("%s: Un-initializing extcon device\n", __func__);
+    otgcontrol_uninit_extcon(otgc_data);
+
     printk("%s: Freeing otgc->pdata\n", __func__);
     kfree(otgc_data->pdata);
 

drivers/misc/rm-otgcontrol/otgcontrol_onewire.c

@@ -11,6 +11,8 @@ int otgcontrol_init_one_wire_mux_state(struct rm_otgcontrol_data *otgc_data)
 
     printk("%s: Initiating one-wire pinctrl states\n", __func__);
     otgc_data->one_wire_pinctrl = devm_pinctrl_get(otgc_data->dev);
+    if (IS_ERR(otgc_data->one_wire_pinctrl))
+        return PTR_ERR(otgc_data->one_wire_pinctrl);
 
     otgc_data->one_wire_pinctrl_states[OTG1_ONEWIRE_STATE__GPIO] = pinctrl_lookup_state(otgc_data->one_wire_pinctrl, "one_wire_gpio");
     if (IS_ERR(otgc_data->one_wire_pinctrl_states[OTG1_ONEWIRE_STATE__GPIO])) {
@@ -89,6 +91,7 @@ int otgcontrol_switch_one_wire_mux_state(struct rm_otgcontrol_data *otgc_data, i
 int otgcontrol_get_current_gpio_state(struct rm_otgcontrol_data *otgc_data)
 {
     printk("%s: Enter\n", __func__);
+
     return 0;
 }
 

drivers/misc/rm-otgcontrol/otgcontrol_sysfs.c

@@ -166,13 +166,15 @@ int otgcontrol_init_sysfs_nodes(struct rm_otgcontrol_data *otgc_data)
     kobject_put(otgc_data->kobject);
     return retval;
 }
-EXPORT_SYMBOL(otgcontrol_init_sysfs_nodes);
+//EXPORT_SYMBOL(otgcontrol_init_sysfs_nodes);
 
 void otgcontrol_uninit_sysfs_nodes(struct rm_otgcontrol_data *otgc_data)
 {
     printk("%s: Enter\n", __func__);
     printk("%s: Decrementing kobject refcount\n", __func__);
-    if(!IS_ERR(otgc_data->kobject))
+    if(!IS_ERR(otgc_data->kobject)) {
         kobject_put(otgc_data->kobject);
+        otgc_data->kobject = NULL;
+    }
 }
-EXPORT_SYMBOL(otgcontrol_uninit_sysfs_nodes);
+//EXPORT_SYMBOL(otgcontrol_uninit_sysfs_nodes);

include/linux/rm-otgcontrol.h

@@ -1,8 +1,9 @@
-#ifndef __RM_OTGCONTROL_H_
+'#ifndef __RM_OTGCONTROL_H_
 #define __RM_OTGCONTROL_H_
 
 #include <linux/kobject.h>
 #include <linux/pinctrl/pinctrl.h>
+#include <linux/extcon.h>
 
 struct rm_otgcontrol_platform_data {
     struct power_supply		*vbus_supply;
@@ -12,6 +13,8 @@ struct rm_otgcontrol_data {
     struct device           		*dev;
     struct rm_otgcontrol_platform_data 	*pdata;
 
+    struct extcon_dev                   *extcon_dev;
+
     int                                 otg_controlstate;
 
     int                                 one_wire_state;