drivers/power/supply/ds2782_battery.c

Source file repositories/reference/linux-study-clean/drivers/power/supply/ds2782_battery.c

File Facts

System
Linux kernel
Corpus path
drivers/power/supply/ds2782_battery.c
Extension
.c
Size
10697 bytes
Lines
445
Domain
Driver Families
Bucket
drivers/power
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct ds278x_battery_ops {
	int (*get_battery_current)(struct ds278x_info *info, int *current_uA);
	int (*get_battery_voltage)(struct ds278x_info *info, int *voltage_uV);
	int (*get_battery_capacity)(struct ds278x_info *info, int *capacity);
};

#define to_ds278x_info(x) power_supply_get_drvdata(x)

struct ds278x_info {
	struct i2c_client	*client;
	struct power_supply	*battery;
	struct power_supply_desc	battery_desc;
	const struct ds278x_battery_ops *ops;
	struct delayed_work	bat_work;
	int                     rsns;
	int			capacity;
	int			status;		/* State Of Charge */
};

static DEFINE_IDA(battery_id);

static inline int ds278x_read_reg(struct ds278x_info *info, int reg, u8 *val)
{
	int ret;

	ret = i2c_smbus_read_byte_data(info->client, reg);
	if (ret < 0) {
		dev_err(&info->client->dev, "register read failed\n");
		return ret;
	}

	*val = ret;
	return 0;
}

static inline int ds278x_read_reg16(struct ds278x_info *info, int reg_msb,
				    s16 *val)
{
	int ret;

	ret = i2c_smbus_read_word_data(info->client, reg_msb);
	if (ret < 0) {
		dev_err(&info->client->dev, "register read failed\n");
		return ret;
	}

	*val = swab16(ret);
	return 0;
}

static int ds278x_get_temp(struct ds278x_info *info, int *temp)
{
	s16 raw;
	int err;

	/*
	 * Temperature is measured in units of 0.125 degrees celcius, the
	 * power_supply class measures temperature in tenths of degrees
	 * celsius. The temperature value is stored as a 10 bit number, plus
	 * sign in the upper bits of a 16 bit register.
	 */
	err = ds278x_read_reg16(info, DS278x_REG_TEMP_MSB, &raw);
	if (err)
		return err;
	*temp = ((raw / 32) * 125) / 100;
	return 0;
}

static int ds2782_get_current(struct ds278x_info *info, int *current_uA)
{
	int sense_res;
	int err;
	u8 sense_res_raw;
	s16 raw;

	/*
	 * The units of measurement for current are dependent on the value of
	 * the sense resistor.
	 */
	err = ds278x_read_reg(info, DS2782_REG_RSNSP, &sense_res_raw);
	if (err)
		return err;
	if (sense_res_raw == 0) {
		dev_err(&info->client->dev, "sense resistor value is 0\n");
		return -ENXIO;
	}
	sense_res = 1000 / sense_res_raw;

	dev_dbg(&info->client->dev, "sense resistor = %d milli-ohms\n",
		sense_res);

Annotation

Implementation Notes