EM/Battery: Charger driver to support the HOST mode functionality

BZ: 26199

Whenever an USB OTG device inserted/removed to the Clovertrail
platform bq24192 charger driver should turn the VBUS ON/OFF and
should be able to support the OTG device functionality. Setting
the GPIO direction to input during the VBUS OFF as not doing it
will break the HOST support on VV boards as GPIO 36 is muxed

Change-Id: I65359d9aa8e75acb5c4f49d4d84313931847e04d
Signed-off-by: Pandey Raj <raj.pandey@intel.com>
Reviewed-on: http://android.intel.com:8080/40182
Reviewed-by: Pallala, Ramakrishna <ramakrishna.pallala@intel.com>
Reviewed-by: Wu, Hao <hao.wu@intel.com>
Tested-by: Kallappa Manjanna, MadhukumarX <madhukumarx.kallappa.manjanna@intel.com>
Reviewed-by: Meng, Zhe <zhe.meng@intel.com>
Tested-by: Meng, Zhe <zhe.meng@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>

diff --git a/drivers/power/bq24192_charger.c b/drivers/power/bq24192_charger.c
index 79260c5..73b0142 100644 (file)
--- a/drivers/power/bq24192_charger.c
+++ b/drivers/power/bq24192_charger.c
@@ -38,6 +38,7 @@
 #include <linux/io.h>
 #include <linux/sched.h>
 #include <linux/delay.h>
+#include <linux/gpio.h>
 
 #define DRV_NAME "bq24192_charger"
 #define DEV_NAME "bq24192"
@@ -71,7 +72,7 @@
 #define CHR_CFG_BIT_LEN                                2
 #define POWER_ON_CFG_CHRG_CFG_DIS              (0 << 4)
 #define POWER_ON_CFG_CHRG_CFG_EN               (1 << 4)
-#define POWER_ON_CFG_CHRG_CFG_OTG              (2 << 4)
+#define POWER_ON_CFG_CHRG_CFG_OTG              (3 << 4)
 #define POWER_ON_CFG_BOOST_LIM                 (1 << 0)
 
 /*
@@ -173,6 +174,8 @@
 
 #define STATUS_UPDATE_INTERVAL         (HZ * 60) /* 60sec */
 
+#define BQ24192_CHRG_OTG_GPIO          36
+
 struct bq24192_chrg_regs {
        u8 in_src;
        u8 pwr_cfg;
@@ -196,6 +199,7 @@ struct bq24192_chip {
 
        /* battery info */
        int batt_status;
+       bool votg;
 };
 
 #ifdef CONFIG_DEBUG_FS
@@ -526,6 +530,61 @@ static void bq24192_monitor_worker(struct work_struct *work)
        schedule_delayed_work(&chip->stat_mon_wrkr, STATUS_UPDATE_INTERVAL);
 }
 
+static int turn_otg_vbus(struct bq24192_chip *chip, bool votg_on)
+{
+       int ret = 0;
+
+       if (votg_on) {
+                       /* Configure the charger in OTG mode */
+                       ret = bq24192_reg_read_modify(chip->client,
+                                       BQ24192_POWER_ON_CFG_REG,
+                                       POWER_ON_CFG_CHRG_CFG_OTG, true);
+                       if (ret < 0) {
+                               dev_warn(&chip->client->dev,
+                                               "read reg modify failed\n");
+                               goto i2c_write_fail;
+                       }
+                       /* Put the charger IC in reverse boost mode. Since
+                        * SDP charger can supply max 500mA charging current
+                        * Setting the boost current to 500mA
+                        */
+                       ret = bq24192_reg_read_modify(chip->client,
+                                       BQ24192_POWER_ON_CFG_REG,
+                                       POWER_ON_CFG_BOOST_LIM, false);
+                       if (ret < 0) {
+                               dev_warn(&chip->client->dev,
+                                               "read reg modify failed\n");
+                               goto i2c_write_fail;
+                       }
+                       /* assert the chrg_otg gpio now */
+                       gpio_direction_output(BQ24192_CHRG_OTG_GPIO, 1);
+       } else {
+                       /* Clear the charger from the OTG mode */
+                       ret = bq24192_reg_read_modify(chip->client,
+                                       BQ24192_POWER_ON_CFG_REG,
+                                       POWER_ON_CFG_CHRG_CFG_OTG, false);
+                       if (ret < 0) {
+                               dev_warn(&chip->client->dev,
+                                               "read reg modify failed\n");
+                               goto i2c_write_fail;
+                       }
+                       /* Put the charger IC out of reverse boost mode 500mA */
+                       ret = bq24192_reg_read_modify(chip->client,
+                                       BQ24192_POWER_ON_CFG_REG,
+                                       POWER_ON_CFG_BOOST_LIM, false);
+                       if (ret < 0) {
+                               dev_warn(&chip->client->dev,
+                                               "read reg modify failed\n");
+                               goto i2c_write_fail;
+                       }
+                       /* de-assert the chrg_otg gpio now */
+                       gpio_direction_output(BQ24192_CHRG_OTG_GPIO, 0);
+                       gpio_direction_input(BQ24192_CHRG_OTG_GPIO);
+       }
+i2c_write_fail:
+       return ret;
+}
+
 static void bq24192_event_worker(struct work_struct *work)
 {
        struct bq24192_chip *chip = container_of(work,
@@ -560,6 +619,17 @@ static void bq24192_event_worker(struct work_struct *work)
                        chip->usb.type = POWER_SUPPLY_TYPE_USB;
                        dev_info(&chip->client->dev,
                                 "Charger type SDP\n");
+               } else if (chip->chrg_type == POWER_SUPPLY_TYPE_USB_HOST) {
+                       dev_info(&chip->client->dev,
+                                "Charger type USB HOST\n");
+                       ret = turn_otg_vbus(chip, true);
+                       if (ret < 0) {
+                               dev_err(&chip->client->dev,
+                               "turning OTG vbus ON failed\n");
+                               goto i2c_write_fail;
+                       }
+                       /* otg vbus is turned ON */
+                       chip->votg = true;
                } else {
                        dev_info(&chip->client->dev,
                                 "Unknown Charger type\n");
@@ -581,10 +651,21 @@ static void bq24192_event_worker(struct work_struct *work)
                        chip->present = 1;
                } else {
                        chip->present = 0;
-                       chip->chrg_type = POWER_SUPPLY_TYPE_USB;
+                       chip->chrg_type = chip->cap.chrg_type;
+                       chip->usb.type = POWER_SUPPLY_TYPE_USB;
                }
                chip->online = 0;
                chip->batt_status = POWER_SUPPLY_STATUS_DISCHARGING;
+               if (chip->votg) {
+                               ret = turn_otg_vbus(chip, false);
+                               if (ret < 0) {
+                                       dev_err(&chip->client->dev,
+                                               "turning OTG vbus OFF failed\n");
+                                       goto i2c_write_fail;
+                               }
+                               /* otg vbus is turned OFF */
+                               chip->votg = false;
+               }
                break;
        default:
                dev_err(&chip->client->dev,
@@ -912,6 +993,15 @@ static int __devinit bq24192_probe(struct i2c_client *client,
                return -EIO;
        }
 
+       ret = gpio_request(BQ24192_CHRG_OTG_GPIO, "CHRG_OTG");
+       if (ret) {
+               dev_err(&chip->client->dev,
+                       "Failed to request gpio %d with error %d\n",
+                       BQ24192_CHRG_OTG_GPIO, ret);
+       }
+       dev_info(&chip->client->dev, "request gpio %d for CHRG_OTG pin\n",
+                       BQ24192_CHRG_OTG_GPIO);
+
        INIT_DELAYED_WORK(&chip->chrg_evt_wrkr, bq24192_event_worker);
        INIT_DELAYED_WORK(&chip->stat_mon_wrkr, bq24192_monitor_worker);
        mutex_init(&chip->event_lock);

diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 6e0f700..1574e24 100644 (file)
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -140,6 +140,7 @@ enum power_supply_type {
        POWER_SUPPLY_TYPE_USB_DCP,      /* Dedicated Charging Port */
        POWER_SUPPLY_TYPE_USB_CDP,      /* Charging Downstream Port */
        POWER_SUPPLY_TYPE_USB_ACA,      /* Accessory Charger Adapters */
+       POWER_SUPPLY_TYPE_USB_HOST,     /* To support OTG devices */
        POWER_SUPPLY_TYPE_UNKNOWN,      /* Supply type Unknown */
 };