power: supply: smb347-charger: Implement USB VBUS regulator
authorDmitry Osipenko <digetx@gmail.com>
Sat, 31 Jul 2021 17:38:39 +0000 (20:38 +0300)
committerSebastian Reichel <sre@kernel.org>
Mon, 16 Aug 2021 15:57:10 +0000 (17:57 +0200)
SMB347 can supply power to USB VBUS, implement the USB VBUS regulator.
USB VBUS needs to be powered for switching OTG-cable USB port into host
mode.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
drivers/power/supply/Kconfig
drivers/power/supply/smb347-charger.c

index 793a6f8ca0805dc5c2c47c75f690e0b04b9b5877..fcc7534edcb2f9cd99b2ab6526b66f59260267b5 100644 (file)
@@ -680,6 +680,7 @@ config CHARGER_BQ256XX
 config CHARGER_SMB347
        tristate "Summit Microelectronics SMB3XX Battery Charger"
        depends on I2C
+       depends on REGULATOR
        select REGMAP_I2C
        help
          Say Y to include support for Summit Microelectronics SMB345,
index 1c9205ca0993bbe2a2822c986526bac83ebb98d8..753944e774c4f3de24440941d805ba014fe933a0 100644 (file)
@@ -18,6 +18,7 @@
 #include <linux/power_supply.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
+#include <linux/regulator/driver.h>
 
 #include <dt-bindings/power/summit,smb347-charger.h>
 
 #define CFG_THERM_SOFT_COLD_COMPENSATION_SHIFT 2
 #define CFG_THERM_MONITOR_DISABLED             BIT(4)
 #define CFG_SYSOK                              0x08
+#define CFG_SYSOK_INOK_ACTIVE_HIGH             BIT(0)
 #define CFG_SYSOK_SUSPEND_HARD_LIMIT_DISABLED  BIT(2)
 #define CFG_OTHER                              0x09
 #define CFG_OTHER_RID_MASK                     0xc0
 #define CFG_OTHER_RID_ENABLED_AUTO_OTG         0xc0
 #define CFG_OTG                                        0x0a
 #define CFG_OTG_TEMP_THRESHOLD_MASK            0x30
+#define CFG_OTG_CURRENT_LIMIT_250mA            BIT(2)
+#define CFG_OTG_CURRENT_LIMIT_750mA            BIT(3)
 #define CFG_OTG_TEMP_THRESHOLD_SHIFT           4
 #define CFG_OTG_CC_COMPENSATION_MASK           0xc0
 #define CFG_OTG_CC_COMPENSATION_SHIFT          6
@@ -92,6 +96,7 @@
 #define CMD_A                                  0x30
 #define CMD_A_CHG_ENABLED                      BIT(1)
 #define CMD_A_SUSPEND_ENABLED                  BIT(2)
+#define CMD_A_OTG_ENABLED                      BIT(4)
 #define CMD_A_ALLOW_WRITE                      BIT(7)
 #define CMD_B                                  0x31
 #define CMD_C                                  0x33
  * @regmap: pointer to driver regmap
  * @mains: power_supply instance for AC/DC power
  * @usb: power_supply instance for USB power
+ * @usb_rdev: USB VBUS regulator device
  * @id: SMB charger ID
  * @mains_online: is AC/DC input connected
  * @usb_online: is USB input connected
  * @irq_unsupported: is interrupt unsupported by SMB hardware
+ * @usb_vbus_enabled: is USB VBUS powered by SMB charger
  * @max_charge_current: maximum current (in uA) the battery can be charged
  * @max_charge_voltage: maximum voltage (in uV) the battery can be charged
  * @pre_charge_current: current (in uA) to use in pre-charging phase
  * @use_usb_otg: USB OTG output can be used (not implemented yet)
  * @enable_control: how charging enable/disable is controlled
  *                 (driver/pin controls)
+ * @inok_polarity: polarity of INOK signal which denotes presence of external
+ *                power supply
  *
  * @use_main, @use_usb, and @use_usb_otg are means to enable/disable
  * hardware support for these. This is useful when we want to have for
@@ -189,10 +198,12 @@ struct smb347_charger {
        struct regmap           *regmap;
        struct power_supply     *mains;
        struct power_supply     *usb;
+       struct regulator_dev    *usb_rdev;
        unsigned int            id;
        bool                    mains_online;
        bool                    usb_online;
        bool                    irq_unsupported;
+       bool                    usb_vbus_enabled;
 
        unsigned int            max_charge_current;
        unsigned int            max_charge_voltage;
@@ -213,6 +224,7 @@ struct smb347_charger {
        bool                    use_usb;
        bool                    use_usb_otg;
        unsigned int            enable_control;
+       unsigned int            inok_polarity;
 };
 
 enum smb_charger_chipid {
@@ -362,6 +374,11 @@ static int smb347_charging_set(struct smb347_charger *smb, bool enable)
                return 0;
        }
 
+       if (enable && smb->usb_vbus_enabled) {
+               dev_dbg(smb->dev, "charging not enabled because USB is in host mode\n");
+               return 0;
+       }
+
        return regmap_update_bits(smb->regmap, CMD_A, CMD_A_CHG_ENABLED,
                                  enable ? CMD_A_CHG_ENABLED : 0);
 }
@@ -1253,6 +1270,13 @@ static void smb347_dt_parse_dev_info(struct smb347_charger *smb)
        /* Select charging control */
        device_property_read_u32(dev, "summit,enable-charge-control",
                                 &smb->enable_control);
+
+       /*
+        * Polarity of INOK signal indicating presence of external power
+        * supply connected to the charger.
+        */
+       device_property_read_u32(dev, "summit,inok-polarity",
+                                &smb->inok_polarity);
 }
 
 static int smb347_get_battery_info(struct smb347_charger *smb)
@@ -1304,6 +1328,160 @@ static int smb347_get_battery_info(struct smb347_charger *smb)
        return 0;
 }
 
+static int smb347_usb_vbus_get_current_limit(struct regulator_dev *rdev)
+{
+       struct smb347_charger *smb = rdev_get_drvdata(rdev);
+       unsigned int val;
+       int ret;
+
+       ret = regmap_read(smb->regmap, CFG_OTG, &val);
+       if (ret < 0)
+               return ret;
+
+       /*
+        * It's unknown what happens if this bit is unset due to lack of
+        * access to the datasheet, assume it's limit-enable.
+        */
+       if (!(val & CFG_OTG_CURRENT_LIMIT_250mA))
+               return 0;
+
+       return val & CFG_OTG_CURRENT_LIMIT_750mA ? 750000 : 250000;
+}
+
+static int smb347_usb_vbus_set_new_current_limit(struct smb347_charger *smb,
+                                                int max_uA)
+{
+       const unsigned int mask = CFG_OTG_CURRENT_LIMIT_750mA |
+                                 CFG_OTG_CURRENT_LIMIT_250mA;
+       unsigned int val = CFG_OTG_CURRENT_LIMIT_250mA;
+       int ret;
+
+       if (max_uA >= 750000)
+               val |= CFG_OTG_CURRENT_LIMIT_750mA;
+
+       ret = regmap_update_bits(smb->regmap, CFG_OTG, mask, val);
+       if (ret < 0)
+               dev_err(smb->dev, "failed to change USB current limit\n");
+
+       return ret;
+}
+
+static int smb347_usb_vbus_set_current_limit(struct regulator_dev *rdev,
+                                            int min_uA, int max_uA)
+{
+       struct smb347_charger *smb = rdev_get_drvdata(rdev);
+       int ret;
+
+       ret = smb347_set_writable(smb, true, true);
+       if (ret < 0)
+               return ret;
+
+       ret = smb347_usb_vbus_set_new_current_limit(smb, max_uA);
+       smb347_set_writable(smb, false, true);
+
+       return ret;
+}
+
+static int smb347_usb_vbus_regulator_enable(struct regulator_dev *rdev)
+{
+       struct smb347_charger *smb = rdev_get_drvdata(rdev);
+       int ret, max_uA;
+
+       ret = smb347_set_writable(smb, true, true);
+       if (ret < 0)
+               return ret;
+
+       smb347_charging_disable(smb);
+
+       if (device_property_read_bool(&rdev->dev, "summit,needs-inok-toggle")) {
+               unsigned int sysok = 0;
+
+               if (smb->inok_polarity == SMB3XX_SYSOK_INOK_ACTIVE_LOW)
+                       sysok = CFG_SYSOK_INOK_ACTIVE_HIGH;
+
+               /*
+                * VBUS won't be powered if INOK is active, so we need to
+                * manually disable INOK on some platforms.
+                */
+               ret = regmap_update_bits(smb->regmap, CFG_SYSOK,
+                                        CFG_SYSOK_INOK_ACTIVE_HIGH, sysok);
+               if (ret < 0) {
+                       dev_err(smb->dev, "failed to disable INOK\n");
+                       goto done;
+               }
+       }
+
+       ret = smb347_usb_vbus_get_current_limit(rdev);
+       if (ret < 0) {
+               dev_err(smb->dev, "failed to get USB VBUS current limit\n");
+               goto done;
+       }
+
+       max_uA = ret;
+
+       ret = smb347_usb_vbus_set_new_current_limit(smb, 250000);
+       if (ret < 0) {
+               dev_err(smb->dev, "failed to preset USB VBUS current limit\n");
+               goto done;
+       }
+
+       ret = regmap_set_bits(smb->regmap, CMD_A, CMD_A_OTG_ENABLED);
+       if (ret < 0) {
+               dev_err(smb->dev, "failed to enable USB VBUS\n");
+               goto done;
+       }
+
+       smb->usb_vbus_enabled = true;
+
+       ret = smb347_usb_vbus_set_new_current_limit(smb, max_uA);
+       if (ret < 0) {
+               dev_err(smb->dev, "failed to restore USB VBUS current limit\n");
+               goto done;
+       }
+done:
+       smb347_set_writable(smb, false, true);
+
+       return ret;
+}
+
+static int smb347_usb_vbus_regulator_disable(struct regulator_dev *rdev)
+{
+       struct smb347_charger *smb = rdev_get_drvdata(rdev);
+       int ret;
+
+       ret = smb347_set_writable(smb, true, true);
+       if (ret < 0)
+               return ret;
+
+       ret = regmap_clear_bits(smb->regmap, CMD_A, CMD_A_OTG_ENABLED);
+       if (ret < 0) {
+               dev_err(smb->dev, "failed to disable USB VBUS\n");
+               goto done;
+       }
+
+       smb->usb_vbus_enabled = false;
+
+       if (device_property_read_bool(&rdev->dev, "summit,needs-inok-toggle")) {
+               unsigned int sysok = 0;
+
+               if (smb->inok_polarity == SMB3XX_SYSOK_INOK_ACTIVE_HIGH)
+                       sysok = CFG_SYSOK_INOK_ACTIVE_HIGH;
+
+               ret = regmap_update_bits(smb->regmap, CFG_SYSOK,
+                                        CFG_SYSOK_INOK_ACTIVE_HIGH, sysok);
+               if (ret < 0) {
+                       dev_err(smb->dev, "failed to enable INOK\n");
+                       goto done;
+               }
+       }
+
+       smb347_start_stop_charging(smb);
+done:
+       smb347_set_writable(smb, false, true);
+
+       return ret;
+}
+
 static const struct regmap_config smb347_regmap = {
        .reg_bits       = 8,
        .val_bits       = 8,
@@ -1314,6 +1492,14 @@ static const struct regmap_config smb347_regmap = {
        .num_reg_defaults_raw = SMB347_MAX_REGISTER,
 };
 
+static const struct regulator_ops smb347_usb_vbus_regulator_ops = {
+       .is_enabled     = regulator_is_enabled_regmap,
+       .enable         = smb347_usb_vbus_regulator_enable,
+       .disable        = smb347_usb_vbus_regulator_disable,
+       .get_current_limit = smb347_usb_vbus_get_current_limit,
+       .set_current_limit = smb347_usb_vbus_set_current_limit,
+};
+
 static const struct power_supply_desc smb347_mains_desc = {
        .name           = "smb347-mains",
        .type           = POWER_SUPPLY_TYPE_MAINS,
@@ -1330,10 +1516,24 @@ static const struct power_supply_desc smb347_usb_desc = {
        .num_properties = ARRAY_SIZE(smb347_properties),
 };
 
+static const struct regulator_desc smb347_usb_vbus_regulator_desc = {
+       .name           = "smb347-usb-vbus",
+       .of_match       = of_match_ptr("usb-vbus"),
+       .ops            = &smb347_usb_vbus_regulator_ops,
+       .type           = REGULATOR_VOLTAGE,
+       .owner          = THIS_MODULE,
+       .enable_reg     = CMD_A,
+       .enable_mask    = CMD_A_OTG_ENABLED,
+       .enable_val     = CMD_A_OTG_ENABLED,
+       .fixed_uV       = 5000000,
+       .n_voltages     = 1,
+};
+
 static int smb347_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
 {
        struct power_supply_config mains_usb_cfg = {};
+       struct regulator_config usb_rdev_cfg = {};
        struct device *dev = &client->dev;
        struct smb347_charger *smb;
        int ret;
@@ -1381,6 +1581,18 @@ static int smb347_probe(struct i2c_client *client,
        if (ret)
                return ret;
 
+       usb_rdev_cfg.dev = dev;
+       usb_rdev_cfg.driver_data = smb;
+       usb_rdev_cfg.regmap = smb->regmap;
+
+       smb->usb_rdev = devm_regulator_register(dev,
+                                               &smb347_usb_vbus_regulator_desc,
+                                               &usb_rdev_cfg);
+       if (IS_ERR(smb->usb_rdev)) {
+               smb347_irq_disable(smb);
+               return PTR_ERR(smb->usb_rdev);
+       }
+
        return 0;
 }
 
@@ -1388,11 +1600,17 @@ static int smb347_remove(struct i2c_client *client)
 {
        struct smb347_charger *smb = i2c_get_clientdata(client);
 
+       smb347_usb_vbus_regulator_disable(smb->usb_rdev);
        smb347_irq_disable(smb);
 
        return 0;
 }
 
+static void smb347_shutdown(struct i2c_client *client)
+{
+       smb347_remove(client);
+}
+
 static const struct i2c_device_id smb347_id[] = {
        { "smb345", SMB345 },
        { "smb347", SMB347 },
@@ -1416,6 +1634,7 @@ static struct i2c_driver smb347_driver = {
        },
        .probe = smb347_probe,
        .remove = smb347_remove,
+       .shutdown = smb347_shutdown,
        .id_table = smb347_id,
 };
 module_i2c_driver(smb347_driver);