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

Sebastian Reichel
2021-08-06T21:14:45Z

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Hi,

On Sat, Jul 31, 2021 at 08:38:39PM +0300, Dmitry Osipenko wrote:
> 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>
> ---

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>

-- Sebastian

> 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
>

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