From: Thomas Antoine <t.antoine@xxxxxxxxxxxx> The interface of the Maxim max77759 fuel gauge has a lot of common with the Maxim max1720x. The major difference is the lack of non-volatile memory slave address. No slave is available at address 0xb of the i2c bus, which is coherent with the following driver from google: line 5836 disables non-volatile memory for m5 gauge. Link: https://android.googlesource.com/kernel/google-modules/bms/+/1a68c36bef474573cc8629cc1d121eb6a81ab68c/max1720x_battery.c Other differences include the lack of V_BATT register to read the battery level and a difference in the way to identify the chip (the same register is used but not the same mask). Add support for the max77759 by allowing to use the non-volatile memory or not based on the chip. Also add the V_CELL regsister as a fallback to read voltage value in the case where read of V_BATT fails. The cast is necessary to avoid an overflow when the value of the register is above 54975 (equivalent to a voltage around 4.29 V). The regmap of the max77759 will lead the read to fail for V_BATT and to correctly use V_CELL instead. This regmap was proposed by André Draszik in Link: https://lore.kernel.org/all/d1bade77b5281c1de6b2ddcb4dbbd033e455a116.camel@xxxxxxxxxx/ Signed-off-by: Thomas Antoine <t.antoine@xxxxxxxxxxxx> --- drivers/power/supply/max1720x_battery.c | 189 +++++++++++++++++++++++++++----- 1 file changed, 164 insertions(+), 25 deletions(-) diff --git a/drivers/power/supply/max1720x_battery.c b/drivers/power/supply/max1720x_battery.c index 33105419e2427bb37963bda9948b647c239f8faa..a41976679eded44fbd13120ad756a626d2867919 100644 --- a/drivers/power/supply/max1720x_battery.c +++ b/drivers/power/supply/max1720x_battery.c @@ -27,6 +27,7 @@ #define MAX172XX_REPCAP 0x05 /* Average capacity */ #define MAX172XX_REPSOC 0x06 /* Percentage of charge */ #define MAX172XX_TEMP 0x08 /* Temperature */ +#define MAX172XX_VCELL 0x09 /* Lowest cell voltage */ #define MAX172XX_CURRENT 0x0A /* Actual current */ #define MAX172XX_AVG_CURRENT 0x0B /* Average current */ #define MAX172XX_TTE 0x11 /* Time to empty */ @@ -39,6 +40,8 @@ #define MAX172XX_DEV_NAME_TYPE_MASK GENMASK(3, 0) #define MAX172XX_DEV_NAME_TYPE_MAX17201 BIT(0) #define MAX172XX_DEV_NAME_TYPE_MAX17205 (BIT(0) | BIT(2)) +#define MAX77759_DEV_NAME_TYPE_MASK GENMASK(15, 9) +#define MAX77759_DEV_NAME_TYPE_MAX77759 0x31 #define MAX172XX_QR_TABLE10 0x22 #define MAX172XX_BATT 0xDA /* Battery voltage */ #define MAX172XX_ATAVCAP 0xDF @@ -46,12 +49,20 @@ static const char *const max1720x_manufacturer = "Maxim Integrated"; static const char *const max17201_model = "MAX17201"; static const char *const max17205_model = "MAX17205"; +static const char *const max77759_model = "MAX77759"; + +enum chip_id { + MAX1720X_ID, + MAX77759_ID, +}; struct max1720x_device_info { struct regmap *regmap; struct regmap *regmap_nv; struct i2c_client *ancillary; int rsense; + int has_nvmem; + enum chip_id id; }; /* @@ -254,6 +265,67 @@ static const enum power_supply_property max1720x_battery_props[] = { POWER_SUPPLY_PROP_MANUFACTURER, }; +/* + * Registers 0x80 up to 0xaf which contain the model for the fuel gauge + * algorithm (stored in nvmem for the max1720x) are locked. They can + * be unlocked by writing 0x59 to 0x62 and 0xc4 to 0x63. They should be + * enabled in the regmap if the driver is extended to manage the model. + */ +static const struct regmap_range max77759_registers[] = { + regmap_reg_range(0x00, 0x4f), + regmap_reg_range(0xb0, 0xbf), + regmap_reg_range(0xd0, 0xd0), + regmap_reg_range(0xdc, 0xdf), + regmap_reg_range(0xfb, 0xfb), + regmap_reg_range(0xff, 0xff), +}; + +static const struct regmap_range max77759_ro_registers[] = { + regmap_reg_range(0x3d, 0x3d), + regmap_reg_range(0xfb, 0xfb), + regmap_reg_range(0xff, 0xff), +}; + +static const struct regmap_access_table max77759_write_table = { + .yes_ranges = max77759_registers, + .n_yes_ranges = ARRAY_SIZE(max77759_registers), + .no_ranges = max77759_ro_registers, + .n_no_ranges = ARRAY_SIZE(max77759_ro_registers), +}; + +static const struct regmap_access_table max77759_rd_table = { + .yes_ranges = max77759_registers, + .n_yes_ranges = ARRAY_SIZE(max77759_registers), +}; + +static const struct regmap_config max77759_regmap_cfg = { + .reg_bits = 8, + .val_bits = 16, + .max_register = 0xff, + .wr_table = &max77759_write_table, + .rd_table = &max77759_rd_table, + .val_format_endian = REGMAP_ENDIAN_LITTLE, + .cache_type = REGCACHE_NONE, +}; + +struct chip_data { + u8 has_nvmem; + const struct regmap_config *regmap_cfg; + enum chip_id id; +}; + +static const struct chip_data max1720x_data = { + .has_nvmem = 1, + .regmap_cfg = &max1720x_regmap_cfg, + .id = MAX1720X_ID, +}; + +static const struct chip_data max77759_data = { + .has_nvmem = 0, + .regmap_cfg = &max77759_regmap_cfg, + .id = MAX77759_ID, +}; + /* Convert regs value to power_supply units */ static int max172xx_time_to_ps(unsigned int reg) @@ -271,6 +343,14 @@ static int max172xx_voltage_to_ps(unsigned int reg) return reg * 1250; /* in uV */ } +// Use 64 bits because computation on 32 bits leads to an overflow +static int max172xx_cell_voltage_to_ps(unsigned int reg) +{ + u64 val = reg; + + return val * 78125 / 1000; /* in uV */ +} + static int max172xx_capacity_to_ps(unsigned int reg) { return reg * 500; /* in uAh */ @@ -303,6 +383,33 @@ static int max172xx_current_to_voltage(unsigned int reg) return val * 156252; } +static int max1720x_devname_to_model(unsigned int reg_val, + union power_supply_propval *val, + struct max1720x_device_info *info) +{ + switch (info->id) { + case MAX1720X_ID: + reg_val = FIELD_GET(MAX172XX_DEV_NAME_TYPE_MASK, reg_val); + if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17201) + val->strval = max17201_model; + else if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17205) + val->strval = max17205_model; + else + return -ENODEV; + break; + case MAX77759_ID: + reg_val = FIELD_GET(MAX77759_DEV_NAME_TYPE_MASK, reg_val); + if (reg_val == MAX77759_DEV_NAME_TYPE_MAX77759) + val->strval = max77759_model; + else + return -ENODEV; + break; + default: + return -ENODEV; + } + return 0; +} + static int max1720x_battery_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) @@ -332,7 +439,12 @@ static int max1720x_battery_get_property(struct power_supply *psy, break; case POWER_SUPPLY_PROP_VOLTAGE_NOW: ret = regmap_read(info->regmap, MAX172XX_BATT, ®_val); - val->intval = max172xx_voltage_to_ps(reg_val); + if (!ret) + val->intval = max172xx_voltage_to_ps(reg_val); + else { + ret = regmap_read(info->regmap, MAX172XX_VCELL, ®_val); + val->intval = max172xx_cell_voltage_to_ps(reg_val); + } break; case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: ret = regmap_read(info->regmap, MAX172XX_DESIGN_CAP, ®_val); @@ -364,13 +476,8 @@ static int max1720x_battery_get_property(struct power_supply *psy, break; case POWER_SUPPLY_PROP_MODEL_NAME: ret = regmap_read(info->regmap, MAX172XX_DEV_NAME, ®_val); - reg_val = FIELD_GET(MAX172XX_DEV_NAME_TYPE_MASK, reg_val); - if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17201) - val->strval = max17201_model; - else if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17205) - val->strval = max17205_model; - else - return -ENODEV; + if (!ret) + ret = max1720x_devname_to_model(reg_val, val, info); break; case POWER_SUPPLY_PROP_MANUFACTURER: val->strval = max1720x_manufacturer; @@ -416,7 +523,6 @@ static int max1720x_probe_nvmem(struct i2c_client *client, .priv = info, }; struct nvmem_device *nvmem; - unsigned int val; int ret; info->ancillary = i2c_new_ancillary_device(client, "nvmem", 0xb); @@ -438,18 +544,6 @@ static int max1720x_probe_nvmem(struct i2c_client *client, return PTR_ERR(info->regmap_nv); } - ret = regmap_read(info->regmap_nv, MAX1720X_NRSENSE, &val); - if (ret < 0) { - dev_err(dev, "Failed to read sense resistor value\n"); - return ret; - } - - info->rsense = val; - if (!info->rsense) { - dev_warn(dev, "RSense not calibrated, set 10 mOhms!\n"); - info->rsense = 1000; /* in regs in 10^-5 */ - } - nvmem = devm_nvmem_register(dev, &nvmem_config); if (IS_ERR(nvmem)) { dev_err(dev, "Could not register nvmem!"); @@ -459,6 +553,36 @@ static int max1720x_probe_nvmem(struct i2c_client *client, return 0; } +static int max1720x_get_rsense(struct device *dev, + struct max1720x_device_info *info) +{ + unsigned int val; + int ret; + + if (info->has_nvmem) { + ret = regmap_read(info->regmap_nv, MAX1720X_NRSENSE, &val); + if (ret < 0) { + dev_err(dev, "Failed to read RSense from nvmem\n"); + return ret; + } + + info->rsense = val; + if (!info->rsense) { + dev_warn(dev, "RSense not calibrated, set 10 mOhms!\n"); + info->rsense = 1000; /* in regs in 10^-5 */ + } + } else { + ret = of_property_read_u32(dev->of_node, + "shunt-resistor-micro-ohms", &val); + if (ret) { + dev_err(dev, "Failed to read RSense from devicetree\n"); + return ret; + } + info->rsense = val/10; + } + return 0; +} + static const struct power_supply_desc max1720x_bat_desc = { .name = "max1720x", .no_thermal = true, @@ -474,6 +598,7 @@ static int max1720x_probe(struct i2c_client *client) struct device *dev = &client->dev; struct max1720x_device_info *info; struct power_supply *bat; + const struct chip_data *data; int ret; info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); @@ -483,14 +608,27 @@ static int max1720x_probe(struct i2c_client *client) psy_cfg.drv_data = info; psy_cfg.fwnode = dev_fwnode(dev); i2c_set_clientdata(client, info); - info->regmap = devm_regmap_init_i2c(client, &max1720x_regmap_cfg); + + data = device_get_match_data(dev); + if (!data) + return dev_err_probe(dev, ret, "Failed to get chip data\n"); + + info->has_nvmem = data->has_nvmem; + info->id = data->id; + info->regmap = devm_regmap_init_i2c(client, data->regmap_cfg); if (IS_ERR(info->regmap)) return dev_err_probe(dev, PTR_ERR(info->regmap), "regmap initialization failed\n"); - ret = max1720x_probe_nvmem(client, info); + if (data->has_nvmem) { + ret = max1720x_probe_nvmem(client, info); + if (ret) + return dev_err_probe(dev, ret, "Failed to probe nvmem\n"); + } + + ret = max1720x_get_rsense(dev, info); if (ret) - return dev_err_probe(dev, ret, "Failed to probe nvmem\n"); + return dev_err_probe(dev, ret, "Failed to get RSense"); bat = devm_power_supply_register(dev, &max1720x_bat_desc, &psy_cfg); if (IS_ERR(bat)) @@ -501,7 +639,8 @@ static int max1720x_probe(struct i2c_client *client) } static const struct of_device_id max1720x_of_match[] = { - { .compatible = "maxim,max17201" }, + { .compatible = "maxim,max17201", .data = (void *) &max1720x_data }, + { .compatible = "maxim,max77759-fg", .data = (void *) &max77759_data }, {} }; MODULE_DEVICE_TABLE(of, max1720x_of_match); -- 2.47.1
