1 /*
2  * Generic battery driver code using IIO
3  * Copyright (C) 2012, Anish Kumar <anish198519851985@gmail.com>
4  * based on jz4740-battery.c
5  * based on s3c_adc_battery.c
6  *
7  * This file is subject to the terms and conditions of the GNU General Public
8  * License.  See the file COPYING in the main directory of this archive for
9  * more details.
10  *
11  */
12 #include <linux/interrupt.h>
13 #include <linux/platform_device.h>
14 #include <linux/power_supply.h>
15 #include <linux/gpio.h>
16 #include <linux/err.h>
17 #include <linux/timer.h>
18 #include <linux/jiffies.h>
19 #include <linux/errno.h>
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/iio/consumer.h>
24 #include <linux/iio/types.h>
25 #include <linux/power/generic-adc-battery.h>
26 
27 #define JITTER_DEFAULT 10 /* hope 10ms is enough */
28 
29 enum gab_chan_type {
30 	GAB_VOLTAGE = 0,
31 	GAB_CURRENT,
32 	GAB_POWER,
33 	GAB_MAX_CHAN_TYPE
34 };
35 
36 /*
37  * gab_chan_name suggests the standard channel names for commonly used
38  * channel types.
39  */
40 static const char *const gab_chan_name[] = {
41 	[GAB_VOLTAGE]	= "voltage",
42 	[GAB_CURRENT]	= "current",
43 	[GAB_POWER]		= "power",
44 };
45 
46 struct gab {
47 	struct power_supply		*psy;
48 	struct power_supply_desc	psy_desc;
49 	struct iio_channel	*channel[GAB_MAX_CHAN_TYPE];
50 	struct gab_platform_data	*pdata;
51 	struct delayed_work bat_work;
52 	int	level;
53 	int	status;
54 	bool cable_plugged;
55 };
56 
57 static struct gab *to_generic_bat(struct power_supply *psy)
58 {
59 	return power_supply_get_drvdata(psy);
60 }
61 
62 static void gab_ext_power_changed(struct power_supply *psy)
63 {
64 	struct gab *adc_bat = to_generic_bat(psy);
65 
66 	schedule_delayed_work(&adc_bat->bat_work, msecs_to_jiffies(0));
67 }
68 
69 static const enum power_supply_property gab_props[] = {
70 	POWER_SUPPLY_PROP_STATUS,
71 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
72 	POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN,
73 	POWER_SUPPLY_PROP_CHARGE_NOW,
74 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
75 	POWER_SUPPLY_PROP_CURRENT_NOW,
76 	POWER_SUPPLY_PROP_TECHNOLOGY,
77 	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
78 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
79 	POWER_SUPPLY_PROP_MODEL_NAME,
80 };
81 
82 /*
83  * This properties are set based on the received platform data and this
84  * should correspond one-to-one with enum chan_type.
85  */
86 static const enum power_supply_property gab_dyn_props[] = {
87 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
88 	POWER_SUPPLY_PROP_CURRENT_NOW,
89 	POWER_SUPPLY_PROP_POWER_NOW,
90 };
91 
92 static bool gab_charge_finished(struct gab *adc_bat)
93 {
94 	struct gab_platform_data *pdata = adc_bat->pdata;
95 	bool ret = gpio_get_value(pdata->gpio_charge_finished);
96 	bool inv = pdata->gpio_inverted;
97 
98 	if (!gpio_is_valid(pdata->gpio_charge_finished))
99 		return false;
100 	return ret ^ inv;
101 }
102 
103 static int gab_get_status(struct gab *adc_bat)
104 {
105 	struct gab_platform_data *pdata = adc_bat->pdata;
106 	struct power_supply_info *bat_info;
107 
108 	bat_info = &pdata->battery_info;
109 	if (adc_bat->level == bat_info->charge_full_design)
110 		return POWER_SUPPLY_STATUS_FULL;
111 	return adc_bat->status;
112 }
113 
114 static enum gab_chan_type gab_prop_to_chan(enum power_supply_property psp)
115 {
116 	switch (psp) {
117 	case POWER_SUPPLY_PROP_POWER_NOW:
118 		return GAB_POWER;
119 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
120 		return GAB_VOLTAGE;
121 	case POWER_SUPPLY_PROP_CURRENT_NOW:
122 		return GAB_CURRENT;
123 	default:
124 		WARN_ON(1);
125 		break;
126 	}
127 	return GAB_POWER;
128 }
129 
130 static int read_channel(struct gab *adc_bat, enum power_supply_property psp,
131 		int *result)
132 {
133 	int ret;
134 	int chan_index;
135 
136 	chan_index = gab_prop_to_chan(psp);
137 	ret = iio_read_channel_processed(adc_bat->channel[chan_index],
138 			result);
139 	if (ret < 0)
140 		pr_err("read channel error\n");
141 	return ret;
142 }
143 
144 static int gab_get_property(struct power_supply *psy,
145 		enum power_supply_property psp, union power_supply_propval *val)
146 {
147 	struct gab *adc_bat;
148 	struct gab_platform_data *pdata;
149 	struct power_supply_info *bat_info;
150 	int result = 0;
151 	int ret = 0;
152 
153 	adc_bat = to_generic_bat(psy);
154 	if (!adc_bat) {
155 		dev_err(&psy->dev, "no battery infos ?!\n");
156 		return -EINVAL;
157 	}
158 	pdata = adc_bat->pdata;
159 	bat_info = &pdata->battery_info;
160 
161 	switch (psp) {
162 	case POWER_SUPPLY_PROP_STATUS:
163 		val->intval = gab_get_status(adc_bat);
164 		break;
165 	case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
166 		val->intval = 0;
167 		break;
168 	case POWER_SUPPLY_PROP_CHARGE_NOW:
169 		val->intval = pdata->cal_charge(result);
170 		break;
171 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
172 	case POWER_SUPPLY_PROP_CURRENT_NOW:
173 	case POWER_SUPPLY_PROP_POWER_NOW:
174 		ret = read_channel(adc_bat, psp, &result);
175 		if (ret < 0)
176 			goto err;
177 		val->intval = result;
178 		break;
179 	case POWER_SUPPLY_PROP_TECHNOLOGY:
180 		val->intval = bat_info->technology;
181 		break;
182 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
183 		val->intval = bat_info->voltage_min_design;
184 		break;
185 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
186 		val->intval = bat_info->voltage_max_design;
187 		break;
188 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
189 		val->intval = bat_info->charge_full_design;
190 		break;
191 	case POWER_SUPPLY_PROP_MODEL_NAME:
192 		val->strval = bat_info->name;
193 		break;
194 	default:
195 		return -EINVAL;
196 	}
197 err:
198 	return ret;
199 }
200 
201 static void gab_work(struct work_struct *work)
202 {
203 	struct gab *adc_bat;
204 	struct gab_platform_data *pdata;
205 	struct delayed_work *delayed_work;
206 	bool is_plugged;
207 	int status;
208 
209 	delayed_work = to_delayed_work(work);
210 	adc_bat = container_of(delayed_work, struct gab, bat_work);
211 	pdata = adc_bat->pdata;
212 	status = adc_bat->status;
213 
214 	is_plugged = power_supply_am_i_supplied(adc_bat->psy);
215 	adc_bat->cable_plugged = is_plugged;
216 
217 	if (!is_plugged)
218 		adc_bat->status =  POWER_SUPPLY_STATUS_DISCHARGING;
219 	else if (gab_charge_finished(adc_bat))
220 		adc_bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
221 	else
222 		adc_bat->status = POWER_SUPPLY_STATUS_CHARGING;
223 
224 	if (status != adc_bat->status)
225 		power_supply_changed(adc_bat->psy);
226 }
227 
228 static irqreturn_t gab_charged(int irq, void *dev_id)
229 {
230 	struct gab *adc_bat = dev_id;
231 	struct gab_platform_data *pdata = adc_bat->pdata;
232 	int delay;
233 
234 	delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
235 	schedule_delayed_work(&adc_bat->bat_work,
236 			msecs_to_jiffies(delay));
237 	return IRQ_HANDLED;
238 }
239 
240 static int gab_probe(struct platform_device *pdev)
241 {
242 	struct gab *adc_bat;
243 	struct power_supply_desc *psy_desc;
244 	struct power_supply_config psy_cfg = {};
245 	struct gab_platform_data *pdata = pdev->dev.platform_data;
246 	enum power_supply_property *properties;
247 	int ret = 0;
248 	int chan;
249 	int index = 0;
250 
251 	adc_bat = devm_kzalloc(&pdev->dev, sizeof(*adc_bat), GFP_KERNEL);
252 	if (!adc_bat) {
253 		dev_err(&pdev->dev, "failed to allocate memory\n");
254 		return -ENOMEM;
255 	}
256 
257 	psy_cfg.drv_data = adc_bat;
258 	psy_desc = &adc_bat->psy_desc;
259 	psy_desc->name = pdata->battery_info.name;
260 
261 	/* bootup default values for the battery */
262 	adc_bat->cable_plugged = false;
263 	adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
264 	psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
265 	psy_desc->get_property = gab_get_property;
266 	psy_desc->external_power_changed = gab_ext_power_changed;
267 	adc_bat->pdata = pdata;
268 
269 	/*
270 	 * copying the static properties and allocating extra memory for holding
271 	 * the extra configurable properties received from platform data.
272 	 */
273 	psy_desc->properties = kcalloc(ARRAY_SIZE(gab_props) +
274 					ARRAY_SIZE(gab_chan_name),
275 					sizeof(*psy_desc->properties),
276 					GFP_KERNEL);
277 	if (!psy_desc->properties) {
278 		ret = -ENOMEM;
279 		goto first_mem_fail;
280 	}
281 
282 	memcpy(psy_desc->properties, gab_props, sizeof(gab_props));
283 	properties = (enum power_supply_property *)
284 			((char *)psy_desc->properties + sizeof(gab_props));
285 
286 	/*
287 	 * getting channel from iio and copying the battery properties
288 	 * based on the channel supported by consumer device.
289 	 */
290 	for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
291 		adc_bat->channel[chan] = iio_channel_get(&pdev->dev,
292 							 gab_chan_name[chan]);
293 		if (IS_ERR(adc_bat->channel[chan])) {
294 			ret = PTR_ERR(adc_bat->channel[chan]);
295 			adc_bat->channel[chan] = NULL;
296 		} else {
297 			/* copying properties for supported channels only */
298 			memcpy(properties + sizeof(*(psy_desc->properties)) * index,
299 					&gab_dyn_props[chan],
300 					sizeof(gab_dyn_props[chan]));
301 			index++;
302 		}
303 	}
304 
305 	/* none of the channels are supported so let's bail out */
306 	if (index == 0) {
307 		ret = -ENODEV;
308 		goto second_mem_fail;
309 	}
310 
311 	/*
312 	 * Total number of properties is equal to static properties
313 	 * plus the dynamic properties.Some properties may not be set
314 	 * as come channels may be not be supported by the device.So
315 	 * we need to take care of that.
316 	 */
317 	psy_desc->num_properties = ARRAY_SIZE(gab_props) + index;
318 
319 	adc_bat->psy = power_supply_register(&pdev->dev, psy_desc, &psy_cfg);
320 	if (IS_ERR(adc_bat->psy)) {
321 		ret = PTR_ERR(adc_bat->psy);
322 		goto err_reg_fail;
323 	}
324 
325 	INIT_DELAYED_WORK(&adc_bat->bat_work, gab_work);
326 
327 	if (gpio_is_valid(pdata->gpio_charge_finished)) {
328 		int irq;
329 		ret = gpio_request(pdata->gpio_charge_finished, "charged");
330 		if (ret)
331 			goto gpio_req_fail;
332 
333 		irq = gpio_to_irq(pdata->gpio_charge_finished);
334 		ret = request_any_context_irq(irq, gab_charged,
335 				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
336 				"battery charged", adc_bat);
337 		if (ret < 0)
338 			goto err_gpio;
339 	}
340 
341 	platform_set_drvdata(pdev, adc_bat);
342 
343 	/* Schedule timer to check current status */
344 	schedule_delayed_work(&adc_bat->bat_work,
345 			msecs_to_jiffies(0));
346 	return 0;
347 
348 err_gpio:
349 	gpio_free(pdata->gpio_charge_finished);
350 gpio_req_fail:
351 	power_supply_unregister(adc_bat->psy);
352 err_reg_fail:
353 	for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
354 		if (adc_bat->channel[chan])
355 			iio_channel_release(adc_bat->channel[chan]);
356 	}
357 second_mem_fail:
358 	kfree(psy_desc->properties);
359 first_mem_fail:
360 	return ret;
361 }
362 
363 static int gab_remove(struct platform_device *pdev)
364 {
365 	int chan;
366 	struct gab *adc_bat = platform_get_drvdata(pdev);
367 	struct gab_platform_data *pdata = adc_bat->pdata;
368 
369 	power_supply_unregister(adc_bat->psy);
370 
371 	if (gpio_is_valid(pdata->gpio_charge_finished)) {
372 		free_irq(gpio_to_irq(pdata->gpio_charge_finished), adc_bat);
373 		gpio_free(pdata->gpio_charge_finished);
374 	}
375 
376 	for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
377 		if (adc_bat->channel[chan])
378 			iio_channel_release(adc_bat->channel[chan]);
379 	}
380 
381 	kfree(adc_bat->psy_desc.properties);
382 	cancel_delayed_work(&adc_bat->bat_work);
383 	return 0;
384 }
385 
386 static int __maybe_unused gab_suspend(struct device *dev)
387 {
388 	struct gab *adc_bat = dev_get_drvdata(dev);
389 
390 	cancel_delayed_work_sync(&adc_bat->bat_work);
391 	adc_bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
392 	return 0;
393 }
394 
395 static int __maybe_unused gab_resume(struct device *dev)
396 {
397 	struct gab *adc_bat = dev_get_drvdata(dev);
398 	struct gab_platform_data *pdata = adc_bat->pdata;
399 	int delay;
400 
401 	delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
402 
403 	/* Schedule timer to check current status */
404 	schedule_delayed_work(&adc_bat->bat_work,
405 			msecs_to_jiffies(delay));
406 	return 0;
407 }
408 
409 static SIMPLE_DEV_PM_OPS(gab_pm_ops, gab_suspend, gab_resume);
410 
411 static struct platform_driver gab_driver = {
412 	.driver		= {
413 		.name	= "generic-adc-battery",
414 		.pm	= &gab_pm_ops,
415 	},
416 	.probe		= gab_probe,
417 	.remove		= gab_remove,
418 };
419 module_platform_driver(gab_driver);
420 
421 MODULE_AUTHOR("anish kumar <anish198519851985@gmail.com>");
422 MODULE_DESCRIPTION("generic battery driver using IIO");
423 MODULE_LICENSE("GPL");
424