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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/power/supply/sbs-manager.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/power/supply/sbs-manager.c | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/drivers/power/supply/sbs-manager.c b/drivers/power/supply/sbs-manager.c new file mode 100644 index 000000000..71ec8f74f --- /dev/null +++ b/drivers/power/supply/sbs-manager.c @@ -0,0 +1,420 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for SBS compliant Smart Battery System Managers + * + * The device communicates via i2c at address 0x0a and multiplexes access to up + * to four smart batteries at address 0x0b. + * + * Via sysfs interface the online state and charge type are presented. + * + * Datasheet SBSM: http://sbs-forum.org/specs/sbsm100b.pdf + * Datasheet LTC1760: http://cds.linear.com/docs/en/datasheet/1760fb.pdf + * + * Karl-Heinz Schneider <karl-heinz@schneider-inet.de> + */ + +#include <linux/gpio/driver.h> +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/i2c-mux.h> +#include <linux/power_supply.h> +#include <linux/property.h> + +#define SBSM_MAX_BATS 4 +#define SBSM_RETRY_CNT 3 + +/* registers addresses */ +#define SBSM_CMD_BATSYSSTATE 0x01 +#define SBSM_CMD_BATSYSSTATECONT 0x02 +#define SBSM_CMD_BATSYSINFO 0x04 +#define SBSM_CMD_LTC 0x3c + +#define SBSM_MASK_BAT_SUPPORTED GENMASK(3, 0) +#define SBSM_MASK_CHARGE_BAT GENMASK(7, 4) +#define SBSM_BIT_AC_PRESENT BIT(0) +#define SBSM_BIT_TURBO BIT(7) + +#define SBSM_SMB_BAT_OFFSET 11 +struct sbsm_data { + struct i2c_client *client; + struct i2c_mux_core *muxc; + + struct power_supply *psy; + + u8 cur_chan; /* currently selected channel */ + struct gpio_chip chip; + bool is_ltc1760; /* special capabilities */ + + unsigned int supported_bats; + unsigned int last_state; + unsigned int last_state_cont; +}; + +static enum power_supply_property sbsm_props[] = { + POWER_SUPPLY_PROP_ONLINE, + POWER_SUPPLY_PROP_CHARGE_TYPE, +}; + +static int sbsm_read_word(struct i2c_client *client, u8 address) +{ + int reg, retries; + + for (retries = SBSM_RETRY_CNT; retries > 0; retries--) { + reg = i2c_smbus_read_word_data(client, address); + if (reg >= 0) + break; + } + + if (reg < 0) { + dev_err(&client->dev, "failed to read register 0x%02x\n", + address); + } + + return reg; +} + +static int sbsm_write_word(struct i2c_client *client, u8 address, u16 word) +{ + int ret, retries; + + for (retries = SBSM_RETRY_CNT; retries > 0; retries--) { + ret = i2c_smbus_write_word_data(client, address, word); + if (ret >= 0) + break; + } + if (ret < 0) + dev_err(&client->dev, "failed to write to register 0x%02x\n", + address); + + return ret; +} + +static int sbsm_get_property(struct power_supply *psy, + enum power_supply_property psp, + union power_supply_propval *val) +{ + struct sbsm_data *data = power_supply_get_drvdata(psy); + int regval = 0; + + switch (psp) { + case POWER_SUPPLY_PROP_ONLINE: + regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATECONT); + if (regval < 0) + return regval; + val->intval = !!(regval & SBSM_BIT_AC_PRESENT); + break; + + case POWER_SUPPLY_PROP_CHARGE_TYPE: + regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE); + if (regval < 0) + return regval; + + if ((regval & SBSM_MASK_CHARGE_BAT) == 0) { + val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE; + return 0; + } + val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE; + + if (data->is_ltc1760) { + /* charge mode fast if turbo is active */ + regval = sbsm_read_word(data->client, SBSM_CMD_LTC); + if (regval < 0) + return regval; + else if (regval & SBSM_BIT_TURBO) + val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST; + } + break; + + default: + return -EINVAL; + } + + return 0; +} + +static int sbsm_prop_is_writeable(struct power_supply *psy, + enum power_supply_property psp) +{ + struct sbsm_data *data = power_supply_get_drvdata(psy); + + return (psp == POWER_SUPPLY_PROP_CHARGE_TYPE) && data->is_ltc1760; +} + +static int sbsm_set_property(struct power_supply *psy, + enum power_supply_property psp, + const union power_supply_propval *val) +{ + struct sbsm_data *data = power_supply_get_drvdata(psy); + int ret = -EINVAL; + u16 regval; + + switch (psp) { + case POWER_SUPPLY_PROP_CHARGE_TYPE: + /* write 1 to TURBO if type fast is given */ + if (!data->is_ltc1760) + break; + regval = val->intval == + POWER_SUPPLY_CHARGE_TYPE_FAST ? SBSM_BIT_TURBO : 0; + ret = sbsm_write_word(data->client, SBSM_CMD_LTC, regval); + break; + + default: + break; + } + + return ret; +} + +/* + * Switch to battery + * Parameter chan is directly the content of SMB_BAT* nibble + */ +static int sbsm_select(struct i2c_mux_core *muxc, u32 chan) +{ + struct sbsm_data *data = i2c_mux_priv(muxc); + struct device *dev = &data->client->dev; + int ret = 0; + u16 reg; + + if (data->cur_chan == chan) + return ret; + + /* chan goes from 1 ... 4 */ + reg = BIT(SBSM_SMB_BAT_OFFSET + chan); + ret = sbsm_write_word(data->client, SBSM_CMD_BATSYSSTATE, reg); + if (ret) + dev_err(dev, "Failed to select channel %i\n", chan); + else + data->cur_chan = chan; + + return ret; +} + +static int sbsm_gpio_get_value(struct gpio_chip *gc, unsigned int off) +{ + struct sbsm_data *data = gpiochip_get_data(gc); + int ret; + + ret = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE); + if (ret < 0) + return ret; + + return ret & BIT(off); +} + +/* + * This needs to be defined or the GPIO lib fails to register the pin. + * But the 'gpio' is always an input. + */ +static int sbsm_gpio_direction_input(struct gpio_chip *gc, unsigned int off) +{ + return 0; +} + +static int sbsm_do_alert(struct device *dev, void *d) +{ + struct i2c_client *client = i2c_verify_client(dev); + struct i2c_driver *driver; + + if (!client || client->addr != 0x0b) + return 0; + + device_lock(dev); + if (client->dev.driver) { + driver = to_i2c_driver(client->dev.driver); + if (driver->alert) + driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT, 0); + else + dev_warn(&client->dev, "no driver alert()!\n"); + } else { + dev_dbg(&client->dev, "alert with no driver\n"); + } + device_unlock(dev); + + return -EBUSY; +} + +static void sbsm_alert(struct i2c_client *client, enum i2c_alert_protocol prot, + unsigned int d) +{ + struct sbsm_data *sbsm = i2c_get_clientdata(client); + + int ret, i, irq_bat = 0, state = 0; + + ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATE); + if (ret >= 0) { + irq_bat = ret ^ sbsm->last_state; + sbsm->last_state = ret; + state = ret; + } + + ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATECONT); + if ((ret >= 0) && + ((ret ^ sbsm->last_state_cont) & SBSM_BIT_AC_PRESENT)) { + irq_bat |= sbsm->supported_bats & state; + power_supply_changed(sbsm->psy); + } + sbsm->last_state_cont = ret; + + for (i = 0; i < SBSM_MAX_BATS; i++) { + if (irq_bat & BIT(i)) { + device_for_each_child(&sbsm->muxc->adapter[i]->dev, + NULL, sbsm_do_alert); + } + } +} + +static int sbsm_gpio_setup(struct sbsm_data *data) +{ + struct gpio_chip *gc = &data->chip; + struct i2c_client *client = data->client; + struct device *dev = &client->dev; + int ret; + + if (!device_property_present(dev, "gpio-controller")) + return 0; + + ret = sbsm_read_word(client, SBSM_CMD_BATSYSSTATE); + if (ret < 0) + return ret; + data->last_state = ret; + + ret = sbsm_read_word(client, SBSM_CMD_BATSYSSTATECONT); + if (ret < 0) + return ret; + data->last_state_cont = ret; + + gc->get = sbsm_gpio_get_value; + gc->direction_input = sbsm_gpio_direction_input; + gc->can_sleep = true; + gc->base = -1; + gc->ngpio = SBSM_MAX_BATS; + gc->label = client->name; + gc->parent = dev; + gc->owner = THIS_MODULE; + + ret = devm_gpiochip_add_data(dev, gc, data); + if (ret) + return dev_err_probe(dev, ret, "devm_gpiochip_add_data failed\n"); + + return ret; +} + +static const struct power_supply_desc sbsm_default_psy_desc = { + .type = POWER_SUPPLY_TYPE_MAINS, + .properties = sbsm_props, + .num_properties = ARRAY_SIZE(sbsm_props), + .get_property = &sbsm_get_property, + .set_property = &sbsm_set_property, + .property_is_writeable = &sbsm_prop_is_writeable, +}; + +static void sbsm_del_mux_adapter(void *data) +{ + struct sbsm_data *sbsm = data; + i2c_mux_del_adapters(sbsm->muxc); +} + +static int sbsm_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct i2c_adapter *adapter = client->adapter; + struct sbsm_data *data; + struct device *dev = &client->dev; + struct power_supply_desc *psy_desc; + struct power_supply_config psy_cfg = {}; + int ret = 0, i; + + /* Device listens only at address 0x0a */ + if (client->addr != 0x0a) + return -EINVAL; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) + return -EPFNOSUPPORT; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + i2c_set_clientdata(client, data); + + data->client = client; + data->is_ltc1760 = !!strstr(id->name, "ltc1760"); + + ret = sbsm_read_word(client, SBSM_CMD_BATSYSINFO); + if (ret < 0) + return ret; + data->supported_bats = ret & SBSM_MASK_BAT_SUPPORTED; + data->muxc = i2c_mux_alloc(adapter, dev, SBSM_MAX_BATS, 0, + I2C_MUX_LOCKED, &sbsm_select, NULL); + if (!data->muxc) + return dev_err_probe(dev, -ENOMEM, "failed to alloc i2c mux\n"); + data->muxc->priv = data; + + ret = devm_add_action_or_reset(dev, sbsm_del_mux_adapter, data); + if (ret) + return ret; + + /* register muxed i2c channels. One for each supported battery */ + for (i = 0; i < SBSM_MAX_BATS; ++i) { + if (data->supported_bats & BIT(i)) { + ret = i2c_mux_add_adapter(data->muxc, 0, i + 1, 0); + if (ret) + break; + } + } + if (ret) + return dev_err_probe(dev, ret, "failed to register i2c mux channel %d\n", i + 1); + + psy_desc = devm_kmemdup(dev, &sbsm_default_psy_desc, sizeof(*psy_desc), GFP_KERNEL); + if (!psy_desc) + return -ENOMEM; + + psy_desc->name = devm_kasprintf(dev, GFP_KERNEL, "sbsm-%s", dev_name(&client->dev)); + if (!psy_desc->name) + return -ENOMEM; + + ret = sbsm_gpio_setup(data); + if (ret < 0) + return ret; + + psy_cfg.drv_data = data; + psy_cfg.of_node = dev->of_node; + data->psy = devm_power_supply_register(dev, psy_desc, &psy_cfg); + if (IS_ERR(data->psy)) + return dev_err_probe(dev, PTR_ERR(data->psy), + "failed to register power supply %s\n", psy_desc->name); + + return 0; +} + +static const struct i2c_device_id sbsm_ids[] = { + { "sbs-manager", 0 }, + { "ltc1760", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, sbsm_ids); + +#ifdef CONFIG_OF +static const struct of_device_id sbsm_dt_ids[] = { + { .compatible = "sbs,sbs-manager" }, + { .compatible = "lltc,ltc1760" }, + { } +}; +MODULE_DEVICE_TABLE(of, sbsm_dt_ids); +#endif + +static struct i2c_driver sbsm_driver = { + .driver = { + .name = "sbsm", + .of_match_table = of_match_ptr(sbsm_dt_ids), + }, + .probe = sbsm_probe, + .alert = sbsm_alert, + .id_table = sbsm_ids +}; +module_i2c_driver(sbsm_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Karl-Heinz Schneider <karl-heinz@schneider-inet.de>"); +MODULE_DESCRIPTION("SBSM Smart Battery System Manager"); |