On 12/3/24 07:47, André Draszik wrote: > Hi Thomas, > > Thanks for looking into this! Hi, With pleasure! This is my first time trying to contribute to the kernel so sorry for any beginner mistakes I might do. >> From: Thomas Antoine <t.antoine@xxxxxxxxxxxx> >> >> The Maxim max77759 fuel gauge has the same interface as the Maxim max1720x >> except for the non-volatile memory slave address which is not available. > > It is not fully compatible, and it also has a lot more registers. > > For example, the voltage now is not in register 0xda as this driver assumes. > With these changes, POWER_SUPPLY_PROP_VOLTAGE_NOW just reads as 0. 0xda > doesn't exist in max77759 > > I haven't compared in depth yet, though. Is the voltage necessary for the driver? If so, we could just not read the voltage. If it is necessary, I can try to kook into it and try to find in which register it is located (if there is one). >> static const char *const max17205_model = "MAX17205"; >> +static const char *const max77759_model = "MAX77759"; >> >> struct max1720x_device_info { >> struct regmap *regmap; >> @@ -54,6 +57,21 @@ struct max1720x_device_info { >> int rsense; >> }; >> >> +struct chip_data { >> + u16 default_nrsense; /* in regs in 10^-5 */ >> + u8 has_nvmem; >> +}; >> + >> +static const struct chip_data max1720x_data = { >> + .default_nrsense = 1000, >> + .has_nvmem = 1, >> +}; >> + >> +static const struct chip_data max77759_data = { >> + .default_nrsense = 500, >> + .has_nvmem = 0, >> +}; > > This should be made a required devicetree property instead, at least for > max77759, as it's completely board dependent, 'shunt-resistor-micro-ohms' > is widely used. > > I also don't think there should be a default. The driver should just fail > to probe if not specified in DT (for max77759). I hesitated to do this but I didn't know what would be better. Will change for v2. >> + >> /* >> * Model Gauge M5 Algorithm output register >> * Volatile data (must not be cached) >> @@ -369,6 +387,8 @@ static int max1720x_battery_get_property(struct >> power_supply *psy, >> val->strval = max17201_model; >> else if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX17205) >> val->strval = max17205_model; >> + else if (reg_val == MAX172XX_DEV_NAME_TYPE_MAX77759) >> + val->strval = max77759_model; >> else > > This is a 16 bit register, and while yes, MAX172XX_DEV_NAME_TYPE_MASK only > cares about the bottom 4 bits, the register is described as 'Firmware > Version Information'. > > But maybe it's ok to do it like that, at least for now. I thought this method would be ok as long as there is no collision on values. I hesitated to change the model evaluation method based on chip model, where the max77759 would thus have an hard-coded value and the max1720x would still evaluate the register value. I did not do it because it led to a lot more changes for no difference. >> &max77759_data}, > > missing space before } Will change for v2. Best regards, Thomas