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442 lines
10 KiB
442 lines
10 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Driver for SBS compliant Smart Battery System Managers |
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* |
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* The device communicates via i2c at address 0x0a and multiplexes access to up |
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* to four smart batteries at address 0x0b. |
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* |
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* Via sysfs interface the online state and charge type are presented. |
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* |
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* Datasheet SBSM: http://sbs-forum.org/specs/sbsm100b.pdf |
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* Datasheet LTC1760: http://cds.linear.com/docs/en/datasheet/1760fb.pdf |
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* |
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* Karl-Heinz Schneider <[email protected]> |
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*/ |
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#include <linux/gpio.h> |
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#include <linux/module.h> |
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#include <linux/i2c.h> |
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#include <linux/i2c-mux.h> |
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#include <linux/power_supply.h> |
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#include <linux/property.h> |
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#define SBSM_MAX_BATS 4 |
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#define SBSM_RETRY_CNT 3 |
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/* registers addresses */ |
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#define SBSM_CMD_BATSYSSTATE 0x01 |
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#define SBSM_CMD_BATSYSSTATECONT 0x02 |
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#define SBSM_CMD_BATSYSINFO 0x04 |
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#define SBSM_CMD_LTC 0x3c |
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#define SBSM_MASK_BAT_SUPPORTED GENMASK(3, 0) |
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#define SBSM_MASK_CHARGE_BAT GENMASK(7, 4) |
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#define SBSM_BIT_AC_PRESENT BIT(0) |
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#define SBSM_BIT_TURBO BIT(7) |
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#define SBSM_SMB_BAT_OFFSET 11 |
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struct sbsm_data { |
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struct i2c_client *client; |
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struct i2c_mux_core *muxc; |
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struct power_supply *psy; |
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u8 cur_chan; /* currently selected channel */ |
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struct gpio_chip chip; |
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bool is_ltc1760; /* special capabilities */ |
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unsigned int supported_bats; |
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unsigned int last_state; |
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unsigned int last_state_cont; |
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}; |
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static enum power_supply_property sbsm_props[] = { |
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POWER_SUPPLY_PROP_ONLINE, |
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POWER_SUPPLY_PROP_CHARGE_TYPE, |
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}; |
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static int sbsm_read_word(struct i2c_client *client, u8 address) |
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{ |
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int reg, retries; |
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for (retries = SBSM_RETRY_CNT; retries > 0; retries--) { |
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reg = i2c_smbus_read_word_data(client, address); |
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if (reg >= 0) |
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break; |
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} |
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if (reg < 0) { |
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dev_err(&client->dev, "failed to read register 0x%02x\n", |
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address); |
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} |
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return reg; |
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} |
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static int sbsm_write_word(struct i2c_client *client, u8 address, u16 word) |
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{ |
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int ret, retries; |
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for (retries = SBSM_RETRY_CNT; retries > 0; retries--) { |
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ret = i2c_smbus_write_word_data(client, address, word); |
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if (ret >= 0) |
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break; |
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} |
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if (ret < 0) |
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dev_err(&client->dev, "failed to write to register 0x%02x\n", |
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address); |
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return ret; |
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} |
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static int sbsm_get_property(struct power_supply *psy, |
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enum power_supply_property psp, |
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union power_supply_propval *val) |
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{ |
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struct sbsm_data *data = power_supply_get_drvdata(psy); |
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int regval = 0; |
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switch (psp) { |
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case POWER_SUPPLY_PROP_ONLINE: |
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regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATECONT); |
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if (regval < 0) |
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return regval; |
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val->intval = !!(regval & SBSM_BIT_AC_PRESENT); |
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break; |
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case POWER_SUPPLY_PROP_CHARGE_TYPE: |
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regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE); |
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if (regval < 0) |
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return regval; |
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if ((regval & SBSM_MASK_CHARGE_BAT) == 0) { |
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val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE; |
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return 0; |
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} |
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val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE; |
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if (data->is_ltc1760) { |
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/* charge mode fast if turbo is active */ |
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regval = sbsm_read_word(data->client, SBSM_CMD_LTC); |
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if (regval < 0) |
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return regval; |
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else if (regval & SBSM_BIT_TURBO) |
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val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST; |
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} |
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break; |
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default: |
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return -EINVAL; |
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} |
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return 0; |
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} |
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static int sbsm_prop_is_writeable(struct power_supply *psy, |
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enum power_supply_property psp) |
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{ |
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struct sbsm_data *data = power_supply_get_drvdata(psy); |
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return (psp == POWER_SUPPLY_PROP_CHARGE_TYPE) && data->is_ltc1760; |
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} |
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static int sbsm_set_property(struct power_supply *psy, |
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enum power_supply_property psp, |
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const union power_supply_propval *val) |
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{ |
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struct sbsm_data *data = power_supply_get_drvdata(psy); |
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int ret = -EINVAL; |
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u16 regval; |
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switch (psp) { |
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case POWER_SUPPLY_PROP_CHARGE_TYPE: |
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/* write 1 to TURBO if type fast is given */ |
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if (!data->is_ltc1760) |
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break; |
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regval = val->intval == |
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POWER_SUPPLY_CHARGE_TYPE_FAST ? SBSM_BIT_TURBO : 0; |
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ret = sbsm_write_word(data->client, SBSM_CMD_LTC, regval); |
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break; |
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default: |
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break; |
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} |
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return ret; |
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} |
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/* |
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* Switch to battery |
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* Parameter chan is directly the content of SMB_BAT* nibble |
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*/ |
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static int sbsm_select(struct i2c_mux_core *muxc, u32 chan) |
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{ |
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struct sbsm_data *data = i2c_mux_priv(muxc); |
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struct device *dev = &data->client->dev; |
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int ret = 0; |
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u16 reg; |
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if (data->cur_chan == chan) |
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return ret; |
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/* chan goes from 1 ... 4 */ |
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reg = BIT(SBSM_SMB_BAT_OFFSET + chan); |
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ret = sbsm_write_word(data->client, SBSM_CMD_BATSYSSTATE, reg); |
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if (ret) |
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dev_err(dev, "Failed to select channel %i\n", chan); |
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else |
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data->cur_chan = chan; |
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return ret; |
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} |
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static int sbsm_gpio_get_value(struct gpio_chip *gc, unsigned int off) |
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{ |
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struct sbsm_data *data = gpiochip_get_data(gc); |
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int ret; |
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ret = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE); |
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if (ret < 0) |
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return ret; |
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return ret & BIT(off); |
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} |
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/* |
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* This needs to be defined or the GPIO lib fails to register the pin. |
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* But the 'gpio' is always an input. |
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*/ |
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static int sbsm_gpio_direction_input(struct gpio_chip *gc, unsigned int off) |
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{ |
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return 0; |
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} |
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static int sbsm_do_alert(struct device *dev, void *d) |
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{ |
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struct i2c_client *client = i2c_verify_client(dev); |
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struct i2c_driver *driver; |
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if (!client || client->addr != 0x0b) |
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return 0; |
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device_lock(dev); |
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if (client->dev.driver) { |
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driver = to_i2c_driver(client->dev.driver); |
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if (driver->alert) |
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driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT, 0); |
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else |
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dev_warn(&client->dev, "no driver alert()!\n"); |
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} else { |
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dev_dbg(&client->dev, "alert with no driver\n"); |
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} |
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device_unlock(dev); |
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return -EBUSY; |
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} |
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static void sbsm_alert(struct i2c_client *client, enum i2c_alert_protocol prot, |
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unsigned int d) |
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{ |
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struct sbsm_data *sbsm = i2c_get_clientdata(client); |
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int ret, i, irq_bat = 0, state = 0; |
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ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATE); |
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if (ret >= 0) { |
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irq_bat = ret ^ sbsm->last_state; |
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sbsm->last_state = ret; |
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state = ret; |
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} |
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ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATECONT); |
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if ((ret >= 0) && |
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((ret ^ sbsm->last_state_cont) & SBSM_BIT_AC_PRESENT)) { |
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irq_bat |= sbsm->supported_bats & state; |
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power_supply_changed(sbsm->psy); |
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} |
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sbsm->last_state_cont = ret; |
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for (i = 0; i < SBSM_MAX_BATS; i++) { |
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if (irq_bat & BIT(i)) { |
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device_for_each_child(&sbsm->muxc->adapter[i]->dev, |
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NULL, sbsm_do_alert); |
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} |
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} |
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} |
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static int sbsm_gpio_setup(struct sbsm_data *data) |
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{ |
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struct gpio_chip *gc = &data->chip; |
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struct i2c_client *client = data->client; |
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struct device *dev = &client->dev; |
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int ret; |
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if (!device_property_present(dev, "gpio-controller")) |
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return 0; |
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ret = sbsm_read_word(client, SBSM_CMD_BATSYSSTATE); |
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if (ret < 0) |
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return ret; |
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data->last_state = ret; |
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ret = sbsm_read_word(client, SBSM_CMD_BATSYSSTATECONT); |
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if (ret < 0) |
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return ret; |
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data->last_state_cont = ret; |
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gc->get = sbsm_gpio_get_value; |
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gc->direction_input = sbsm_gpio_direction_input; |
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gc->can_sleep = true; |
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gc->base = -1; |
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gc->ngpio = SBSM_MAX_BATS; |
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gc->label = client->name; |
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gc->parent = dev; |
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gc->owner = THIS_MODULE; |
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ret = devm_gpiochip_add_data(dev, gc, data); |
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if (ret) { |
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dev_err(dev, "devm_gpiochip_add_data failed: %d\n", ret); |
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return ret; |
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} |
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return ret; |
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} |
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static const struct power_supply_desc sbsm_default_psy_desc = { |
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.type = POWER_SUPPLY_TYPE_MAINS, |
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.properties = sbsm_props, |
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.num_properties = ARRAY_SIZE(sbsm_props), |
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.get_property = &sbsm_get_property, |
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.set_property = &sbsm_set_property, |
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.property_is_writeable = &sbsm_prop_is_writeable, |
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}; |
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static int sbsm_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct i2c_adapter *adapter = client->adapter; |
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struct sbsm_data *data; |
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struct device *dev = &client->dev; |
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struct power_supply_desc *psy_desc; |
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struct power_supply_config psy_cfg = {}; |
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int ret = 0, i; |
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/* Device listens only at address 0x0a */ |
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if (client->addr != 0x0a) |
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return -EINVAL; |
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) |
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return -EPFNOSUPPORT; |
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data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); |
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if (!data) |
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return -ENOMEM; |
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i2c_set_clientdata(client, data); |
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data->client = client; |
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data->is_ltc1760 = !!strstr(id->name, "ltc1760"); |
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ret = sbsm_read_word(client, SBSM_CMD_BATSYSINFO); |
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if (ret < 0) |
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return ret; |
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data->supported_bats = ret & SBSM_MASK_BAT_SUPPORTED; |
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data->muxc = i2c_mux_alloc(adapter, dev, SBSM_MAX_BATS, 0, |
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I2C_MUX_LOCKED, &sbsm_select, NULL); |
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if (!data->muxc) { |
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dev_err(dev, "failed to alloc i2c mux\n"); |
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ret = -ENOMEM; |
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goto err_mux_alloc; |
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} |
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data->muxc->priv = data; |
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/* register muxed i2c channels. One for each supported battery */ |
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for (i = 0; i < SBSM_MAX_BATS; ++i) { |
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if (data->supported_bats & BIT(i)) { |
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ret = i2c_mux_add_adapter(data->muxc, 0, i + 1, 0); |
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if (ret) |
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break; |
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} |
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} |
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if (ret) { |
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dev_err(dev, "failed to register i2c mux channel %d\n", i + 1); |
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goto err_mux_register; |
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} |
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psy_desc = devm_kmemdup(dev, &sbsm_default_psy_desc, |
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sizeof(struct power_supply_desc), |
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GFP_KERNEL); |
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if (!psy_desc) { |
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ret = -ENOMEM; |
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goto err_psy; |
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} |
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psy_desc->name = devm_kasprintf(dev, GFP_KERNEL, "sbsm-%s", |
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dev_name(&client->dev)); |
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if (!psy_desc->name) { |
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ret = -ENOMEM; |
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goto err_psy; |
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} |
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ret = sbsm_gpio_setup(data); |
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if (ret < 0) |
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goto err_psy; |
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psy_cfg.drv_data = data; |
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psy_cfg.of_node = dev->of_node; |
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data->psy = devm_power_supply_register(dev, psy_desc, &psy_cfg); |
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if (IS_ERR(data->psy)) { |
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ret = PTR_ERR(data->psy); |
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dev_err(dev, "failed to register power supply %s\n", |
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psy_desc->name); |
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goto err_psy; |
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} |
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return 0; |
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err_psy: |
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err_mux_register: |
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i2c_mux_del_adapters(data->muxc); |
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err_mux_alloc: |
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return ret; |
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} |
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static int sbsm_remove(struct i2c_client *client) |
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{ |
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struct sbsm_data *data = i2c_get_clientdata(client); |
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i2c_mux_del_adapters(data->muxc); |
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return 0; |
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} |
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static const struct i2c_device_id sbsm_ids[] = { |
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{ "sbs-manager", 0 }, |
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{ "ltc1760", 0 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, sbsm_ids); |
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#ifdef CONFIG_OF |
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static const struct of_device_id sbsm_dt_ids[] = { |
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{ .compatible = "sbs,sbs-manager" }, |
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{ .compatible = "lltc,ltc1760" }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, sbsm_dt_ids); |
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#endif |
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static struct i2c_driver sbsm_driver = { |
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.driver = { |
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.name = "sbsm", |
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.of_match_table = of_match_ptr(sbsm_dt_ids), |
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}, |
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.probe = sbsm_probe, |
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.remove = sbsm_remove, |
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.alert = sbsm_alert, |
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.id_table = sbsm_ids |
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}; |
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module_i2c_driver(sbsm_driver); |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("Karl-Heinz Schneider <[email protected]>"); |
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MODULE_DESCRIPTION("SBSM Smart Battery System Manager");
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