diff --git a/drivers/power/supply/sbs-battery.c b/drivers/power/supply/sbs-battery.c index a9a1d28dabbe..ab774d491269 100644 --- a/drivers/power/supply/sbs-battery.c +++ b/drivers/power/supply/sbs-battery.c @@ -46,6 +46,14 @@ enum { REG_MODEL_NAME, }; +#define REG_ADDR_SPEC_INFO 0x1A +#define SPEC_INFO_VERSION_MASK GENMASK(7, 4) +#define SPEC_INFO_VERSION_SHIFT 4 + +#define SBS_VERSION_1_0 1 +#define SBS_VERSION_1_1 2 +#define SBS_VERSION_1_1_WITH_PEC 3 + /* Battery Mode defines */ #define BATTERY_MODE_OFFSET 0x03 #define BATTERY_MODE_CAPACITY_MASK BIT(15) @@ -175,6 +183,64 @@ static char model_name[I2C_SMBUS_BLOCK_MAX + 1]; static char manufacturer[I2C_SMBUS_BLOCK_MAX + 1]; static bool force_load; +static int sbs_update_presence(struct sbs_info *chip, bool is_present) +{ + struct i2c_client *client = chip->client; + int retries = chip->i2c_retry_count; + s32 ret = 0; + u8 version; + + if (chip->is_present == is_present) + return 0; + + if (!is_present) { + chip->is_present = false; + /* Disable PEC when no device is present */ + client->flags &= ~I2C_CLIENT_PEC; + return 0; + } + + /* Check if device supports packet error checking and use it */ + while (retries > 0) { + ret = i2c_smbus_read_word_data(client, REG_ADDR_SPEC_INFO); + if (ret >= 0) + break; + + /* + * Some batteries trigger the detection pin before the + * I2C bus is properly connected. This works around the + * issue. + */ + msleep(100); + + retries--; + } + + if (ret < 0) { + dev_dbg(&client->dev, "failed to read spec info: %d\n", ret); + + /* fallback to old behaviour */ + client->flags &= ~I2C_CLIENT_PEC; + chip->is_present = true; + + return ret; + } + + version = (ret & SPEC_INFO_VERSION_MASK) >> SPEC_INFO_VERSION_SHIFT; + + if (version == SBS_VERSION_1_1_WITH_PEC) + client->flags |= I2C_CLIENT_PEC; + else + client->flags &= ~I2C_CLIENT_PEC; + + dev_dbg(&client->dev, "PEC: %s\n", (client->flags & I2C_CLIENT_PEC) ? + "enabled" : "disabled"); + + chip->is_present = true; + + return 0; +} + static int sbs_read_word_data(struct i2c_client *client, u8 address) { struct sbs_info *chip = i2c_get_clientdata(client); @@ -579,7 +645,7 @@ static int sbs_get_property(struct power_supply *psy, return ret; if (psp == POWER_SUPPLY_PROP_PRESENT) { val->intval = ret; - chip->is_present = val->intval; + sbs_update_presence(chip, ret); return 0; } if (ret == 0) @@ -678,7 +744,7 @@ static int sbs_get_property(struct power_supply *psy, if (!chip->gpio_detect && chip->is_present != (ret >= 0)) { - chip->is_present = (ret >= 0); + sbs_update_presence(chip, (ret >= 0)); power_supply_changed(chip->power_supply); } @@ -709,7 +775,7 @@ static void sbs_supply_changed(struct sbs_info *chip) ret = gpiod_get_value_cansleep(chip->gpio_detect); if (ret < 0) return; - chip->is_present = ret; + sbs_update_presence(chip, ret); power_supply_changed(battery); }