1 // SPDX-License-Identifier: GPL-2.0+
5  * Note the uG3105 is not a full-featured autonomous fuel-gauge. Instead it is
6  * expected to be use in combination with some always on microcontroller reading
7  * its coulomb-counter before it can wrap (must be read every 400 seconds!).
9  * Since Linux does not monitor coulomb-counter changes while the device
19  * 4. Add some mechanism (needs userspace help, or maybe use efivar?) to remember
23  *    and then use total_coulomb_count to report energy_now over time, resetting
25  *    readings, esp. in the 30-70% range and allow userspace to estimate time
28  *    capacity during run-time ?
32  * in a total_coulomb_count increase of 3277 units with a 5 milli-ohm sense R.
37 #include <linux/devm-helpers.h>
75 	int ocv[UG3105_MOV_AVG_WINDOW];		/* micro-volt */
76 	int intern_res[UG3105_MOV_AVG_WINDOW];	/* milli-ohm */
79 	int ocv_avg;				/* micro-volt */
82 	int intern_res_avg;			/* milli-ohm */
83 	int volt;				/* micro-volt */
84 	int curr;				/* micro-ampere */
99 		dev_err(&client->dev, "Error reading reg 0x%02x\n", reg);  in ug3105_read_word()
106 	int full = chip->info->constant_charge_voltage_max_uv - UG3105_FULL_BAT_HYST_UV;  in ug3105_get_status()
108 	if (chip->curr > UG3105_CURR_HYST_UA)  in ug3105_get_status()
111 	if (chip->curr < -UG3105_CURR_HYST_UA)  in ug3105_get_status()
114 	if (chip->supplied && chip->ocv_avg > full)  in ug3105_get_status()
123 	 * OCV voltages in uV for 0-110% in 5% increments, the 100-110% is  in ug3105_get_capacity()
124 	 * for LiPo HV (High-Voltage) bateries which can go up to 4.35V  in ug3105_get_capacity()
154 	if (chip->ocv_avg < ocv_capacity_tbl[0])  in ug3105_get_capacity()
157 	if (chip->status == POWER_SUPPLY_STATUS_FULL)  in ug3105_get_capacity()
161 		if (chip->ocv_avg > ocv_capacity_tbl[i])  in ug3105_get_capacity()
164 		ocv_diff = ocv_capacity_tbl[i] - chip->ocv_avg;  in ug3105_get_capacity()
165 		ocv_step = ocv_capacity_tbl[i] - ocv_capacity_tbl[i - 1];  in ug3105_get_capacity()
166 		/* scale 0-110% down to 0-100% for LiPo HV */  in ug3105_get_capacity()
167 		if (chip->info->constant_charge_voltage_max_uv >= 4300000)  in ug3105_get_capacity()
168 			return (i * 500 - ocv_diff * 500 / ocv_step) / 110;  in ug3105_get_capacity()
170 			return i * 5 - ocv_diff * 5 / ocv_step;  in ug3105_get_capacity()
180 	int i, val, curr_diff, volt_diff, res, win_size;  in ug3105_work()  local
181 	bool prev_supplied = chip->supplied;  in ug3105_work()
182 	int prev_status = chip->status;  in ug3105_work()
183 	int prev_volt = chip->volt;  in ug3105_work()
184 	int prev_curr = chip->curr;  in ug3105_work()
187 	mutex_lock(&chip->lock);  in ug3105_work()
189 	psy = chip->psy;  in ug3105_work()
193 	val = ug3105_read_word(chip->client, UG3105_REG_BAT_VOLT);  in ug3105_work()
196 	chip->volt = val * chip->uv_per_unit;  in ug3105_work()
198 	val = ug3105_read_word(chip->client, UG3105_REG_BAT_CURR);  in ug3105_work()
201 	chip->curr = (s16)val * chip->ua_per_unit;  in ug3105_work()
203 	chip->ocv[chip->ocv_avg_index] =  in ug3105_work()
204 		chip->volt - chip->curr * chip->intern_res_avg / 1000;  in ug3105_work()
205 	chip->ocv_avg_index = (chip->ocv_avg_index + 1) % UG3105_MOV_AVG_WINDOW;  in ug3105_work()
206 	chip->poll_count++;  in ug3105_work()
212 	 * if ((chip->poll_count % 10) == 0) {  in ug3105_work()
213 	 *	val = ug3105_read_word(chip->client, UG3105_REG_COULOMB_CNT);  in ug3105_work()
217 	 *	i2c_smbus_write_byte_data(chip->client, UG3105_REG_CTRL1,  in ug3105_work()
220 	 *	chip->total_coulomb_count += (s16)val;  in ug3105_work()
221 	 *	dev_dbg(&chip->client->dev, "coulomb count %d total %d\n",  in ug3105_work()
222 	 *		(s16)val, chip->total_coulomb_count);  in ug3105_work()
226 	chip->ocv_avg = 0;  in ug3105_work()
227 	win_size = min(chip->poll_count, UG3105_MOV_AVG_WINDOW);  in ug3105_work()
229 		chip->ocv_avg += chip->ocv[i];  in ug3105_work()
230 	chip->ocv_avg /= win_size;  in ug3105_work()
232 	chip->supplied = power_supply_am_i_supplied(psy);  in ug3105_work()
233 	chip->status = ug3105_get_status(chip);  in ug3105_work()
234 	chip->capacity = ug3105_get_capacity(chip);  in ug3105_work()
240 	if (chip->supplied != prev_supplied ||  in ug3105_work()
241 	    chip->volt < UG3105_LOW_BAT_UV ||  in ug3105_work()
242 	    chip->poll_count < 2)  in ug3105_work()
251 	curr_diff = abs(chip->curr - prev_curr);  in ug3105_work()
255 	volt_diff = abs(chip->volt - prev_volt);  in ug3105_work()
256 	res = volt_diff * 1000 / curr_diff;  in ug3105_work()
258 	if ((res < (chip->intern_res_avg * 2 / 3)) ||  in ug3105_work()
259 	    (res > (chip->intern_res_avg * 4 / 3))) {  in ug3105_work()
260 		dev_dbg(&chip->client->dev, "Ignoring outlier internal resistance %d mOhm\n", res);  in ug3105_work()
264 	dev_dbg(&chip->client->dev, "Internal resistance %d mOhm\n", res);  in ug3105_work()
266 	chip->intern_res[chip->intern_res_avg_index] = res;  in ug3105_work()
267 	chip->intern_res_avg_index = (chip->intern_res_avg_index + 1) % UG3105_MOV_AVG_WINDOW;  in ug3105_work()
268 	chip->intern_res_poll_count++;  in ug3105_work()
270 	chip->intern_res_avg = 0;  in ug3105_work()
271 	win_size = min(chip->intern_res_poll_count, UG3105_MOV_AVG_WINDOW);  in ug3105_work()
273 		chip->intern_res_avg += chip->intern_res[i];  in ug3105_work()
274 	chip->intern_res_avg /= win_size;  in ug3105_work()
277 	mutex_unlock(&chip->lock);  in ug3105_work()
279 	queue_delayed_work(system_wq, &chip->work,  in ug3105_work()
280 			   (chip->poll_count <= UG3105_INIT_POLL_COUNT) ?  in ug3105_work()
283 	if (chip->status != prev_status && psy)  in ug3105_work()
305 	mutex_lock(&chip->lock);  in ug3105_get_property()
307 	if (!chip->psy) {  in ug3105_get_property()
308 		ret = -EAGAIN;  in ug3105_get_property()
314 		val->intval = chip->status;  in ug3105_get_property()
317 		val->intval = 1;  in ug3105_get_property()
320 		val->intval = chip->info->technology;  in ug3105_get_property()
323 		val->intval = POWER_SUPPLY_SCOPE_SYSTEM;  in ug3105_get_property()
326 		ret = ug3105_read_word(chip->client, UG3105_REG_BAT_VOLT);  in ug3105_get_property()
329 		val->intval = ret * chip->uv_per_unit;  in ug3105_get_property()
333 		val->intval = chip->ocv_avg;  in ug3105_get_property()
336 		ret = ug3105_read_word(chip->client, UG3105_REG_BAT_CURR);  in ug3105_get_property()
339 		val->intval = (s16)ret * chip->ua_per_unit;  in ug3105_get_property()
343 		val->intval = chip->capacity;  in ug3105_get_property()
346 		ret = -EINVAL;  in ug3105_get_property()
350 	mutex_unlock(&chip->lock);  in ug3105_get_property()
358 	dev_dbg(&chip->client->dev, "external power changed\n");  in ug3105_external_power_changed()
359 	mod_delayed_work(system_wq, &chip->work, UG3105_SETTLE_TIME);  in ug3105_external_power_changed()
373 	chip->poll_count = 0;  in ug3105_init()
374 	chip->ocv_avg_index = 0;  in ug3105_init()
375 	chip->total_coulomb_count = 0;  in ug3105_init()
376 	i2c_smbus_write_byte_data(chip->client, UG3105_REG_MODE,  in ug3105_init()
378 	i2c_smbus_write_byte_data(chip->client, UG3105_REG_CTRL1,  in ug3105_init()
380 	queue_delayed_work(system_wq, &chip->work, 0);  in ug3105_init()
381 	flush_delayed_work(&chip->work);  in ug3105_init()
387 	struct device *dev = &client->dev;  in ug3105_probe()
395 		return -ENOMEM;  in ug3105_probe()
397 	chip->client = client;  in ug3105_probe()
398 	mutex_init(&chip->lock);  in ug3105_probe()
399 	ret = devm_delayed_work_autocancel(dev, &chip->work, ug3105_work);  in ug3105_probe()
408 	ret = power_supply_get_battery_info(psy, &chip->info);  in ug3105_probe()
412 	if (chip->info->factory_internal_resistance_uohm == -EINVAL ||  in ug3105_probe()
413 	    chip->info->constant_charge_voltage_max_uv == -EINVAL) {  in ug3105_probe()
415 		return -ENODEV;  in ug3105_probe()
418 	device_property_read_u32(dev, "upisemi,rsns-microohm", &curr_sense_res_uohm);  in ug3105_probe()
422 	 * coming from somewhere for some reason (verified with a volt-meter).  in ug3105_probe()
424 	chip->uv_per_unit = 45000000/65536;  in ug3105_probe()
425 	/* Datasheet says 8.1 uV per unit for the current ADC */  in ug3105_probe()
426 	chip->ua_per_unit = 8100000 / curr_sense_res_uohm;  in ug3105_probe()
428 	/* Use provided internal resistance as start point (in milli-ohm) */  in ug3105_probe()
429 	chip->intern_res_avg = chip->info->factory_internal_resistance_uohm / 1000;  in ug3105_probe()
431 	chip->intern_res[0] = chip->intern_res_avg;  in ug3105_probe()
432 	chip->intern_res_avg_index = 1;  in ug3105_probe()
433 	chip->intern_res_poll_count = 1;  in ug3105_probe()
435 	mutex_lock(&chip->lock);  in ug3105_probe()
436 	chip->psy = psy;  in ug3105_probe()
437 	mutex_unlock(&chip->lock);  in ug3105_probe()
449 	cancel_delayed_work_sync(&chip->work);  in ug3105_suspend()
450 	i2c_smbus_write_byte_data(chip->client, UG3105_REG_MODE,  in ug3105_suspend()