[PATCH v6 09/12] power: supply: smb347-charger: Implement USB VBUS regulator

Dmitry Osipenko
2021-07-31T17:39:25Z

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>
---
drivers/power/supply/Kconfig | 1 +
drivers/power/supply/smb347-charger.c | 219 ++++++++++++++++++++++++++
2 files changed, 220 insertions(+)

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 8543c89a0c1a..e83e9e4d512c 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -694,6 +694,7 @@ 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,
diff --git a/drivers/power/supply/smb347-charger.c b/drivers/power/supply/smb347-charger.c
index 1c9205ca0993..753944e774c4 100644
--- a/drivers/power/supply/smb347-charger.c
+++ b/drivers/power/supply/smb347-charger.c
@@ -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>

@@ -63,12 +64,15 @@
#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
@@ -133,10 +138,12 @@
* @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
@@ -167,6 +174,8 @@
* @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);
--
2.32.0