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
to_generic_bat(struct power_supply * psy)57 static struct gab *to_generic_bat(struct power_supply *psy)
58 {
59 return power_supply_get_drvdata(psy);
60 }
61
gab_ext_power_changed(struct power_supply * psy)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
gab_charge_finished(struct gab * adc_bat)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
gab_get_status(struct gab * adc_bat)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
gab_prop_to_chan(enum power_supply_property psp)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
read_channel(struct gab * adc_bat,enum power_supply_property psp,int * result)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
gab_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)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
gab_work(struct work_struct * work)201 static void gab_work(struct work_struct *work)
202 {
203 struct gab *adc_bat;
204 struct delayed_work *delayed_work;
205 bool is_plugged;
206 int status;
207
208 delayed_work = to_delayed_work(work);
209 adc_bat = container_of(delayed_work, struct gab, bat_work);
210 status = adc_bat->status;
211
212 is_plugged = power_supply_am_i_supplied(adc_bat->psy);
213 adc_bat->cable_plugged = is_plugged;
214
215 if (!is_plugged)
216 adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
217 else if (gab_charge_finished(adc_bat))
218 adc_bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
219 else
220 adc_bat->status = POWER_SUPPLY_STATUS_CHARGING;
221
222 if (status != adc_bat->status)
223 power_supply_changed(adc_bat->psy);
224 }
225
gab_charged(int irq,void * dev_id)226 static irqreturn_t gab_charged(int irq, void *dev_id)
227 {
228 struct gab *adc_bat = dev_id;
229 struct gab_platform_data *pdata = adc_bat->pdata;
230 int delay;
231
232 delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
233 schedule_delayed_work(&adc_bat->bat_work,
234 msecs_to_jiffies(delay));
235 return IRQ_HANDLED;
236 }
237
gab_probe(struct platform_device * pdev)238 static int gab_probe(struct platform_device *pdev)
239 {
240 struct gab *adc_bat;
241 struct power_supply_desc *psy_desc;
242 struct power_supply_config psy_cfg = {};
243 struct gab_platform_data *pdata = pdev->dev.platform_data;
244 enum power_supply_property *properties;
245 int ret = 0;
246 int chan;
247 int index = ARRAY_SIZE(gab_props);
248 bool any = false;
249
250 adc_bat = devm_kzalloc(&pdev->dev, sizeof(*adc_bat), GFP_KERNEL);
251 if (!adc_bat) {
252 dev_err(&pdev->dev, "failed to allocate memory\n");
253 return -ENOMEM;
254 }
255
256 psy_cfg.drv_data = adc_bat;
257 psy_desc = &adc_bat->psy_desc;
258 psy_desc->name = pdata->battery_info.name;
259
260 /* bootup default values for the battery */
261 adc_bat->cable_plugged = false;
262 adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
263 psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
264 psy_desc->get_property = gab_get_property;
265 psy_desc->external_power_changed = gab_ext_power_changed;
266 adc_bat->pdata = pdata;
267
268 /*
269 * copying the static properties and allocating extra memory for holding
270 * the extra configurable properties received from platform data.
271 */
272 properties = kcalloc(ARRAY_SIZE(gab_props) +
273 ARRAY_SIZE(gab_chan_name),
274 sizeof(*properties),
275 GFP_KERNEL);
276 if (!properties) {
277 ret = -ENOMEM;
278 goto first_mem_fail;
279 }
280
281 memcpy(properties, gab_props, sizeof(gab_props));
282
283 /*
284 * getting channel from iio and copying the battery properties
285 * based on the channel supported by consumer device.
286 */
287 for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
288 adc_bat->channel[chan] = iio_channel_get(&pdev->dev,
289 gab_chan_name[chan]);
290 if (IS_ERR(adc_bat->channel[chan])) {
291 ret = PTR_ERR(adc_bat->channel[chan]);
292 adc_bat->channel[chan] = NULL;
293 } else {
294 /* copying properties for supported channels only */
295 int index2;
296
297 for (index2 = 0; index2 < index; index2++) {
298 if (properties[index2] == gab_dyn_props[chan])
299 break; /* already known */
300 }
301 if (index2 == index) /* really new */
302 properties[index++] = gab_dyn_props[chan];
303 any = true;
304 }
305 }
306
307 /* none of the channels are supported so let's bail out */
308 if (!any) {
309 ret = -ENODEV;
310 goto second_mem_fail;
311 }
312
313 /*
314 * Total number of properties is equal to static properties
315 * plus the dynamic properties.Some properties may not be set
316 * as come channels may be not be supported by the device.So
317 * we need to take care of that.
318 */
319 psy_desc->properties = properties;
320 psy_desc->num_properties = index;
321
322 adc_bat->psy = power_supply_register(&pdev->dev, psy_desc, &psy_cfg);
323 if (IS_ERR(adc_bat->psy)) {
324 ret = PTR_ERR(adc_bat->psy);
325 goto err_reg_fail;
326 }
327
328 INIT_DELAYED_WORK(&adc_bat->bat_work, gab_work);
329
330 if (gpio_is_valid(pdata->gpio_charge_finished)) {
331 int irq;
332 ret = gpio_request(pdata->gpio_charge_finished, "charged");
333 if (ret)
334 goto gpio_req_fail;
335
336 irq = gpio_to_irq(pdata->gpio_charge_finished);
337 ret = request_any_context_irq(irq, gab_charged,
338 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
339 "battery charged", adc_bat);
340 if (ret < 0)
341 goto err_gpio;
342 }
343
344 platform_set_drvdata(pdev, adc_bat);
345
346 /* Schedule timer to check current status */
347 schedule_delayed_work(&adc_bat->bat_work,
348 msecs_to_jiffies(0));
349 return 0;
350
351 err_gpio:
352 gpio_free(pdata->gpio_charge_finished);
353 gpio_req_fail:
354 power_supply_unregister(adc_bat->psy);
355 err_reg_fail:
356 for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
357 if (adc_bat->channel[chan])
358 iio_channel_release(adc_bat->channel[chan]);
359 }
360 second_mem_fail:
361 kfree(properties);
362 first_mem_fail:
363 return ret;
364 }
365
gab_remove(struct platform_device * pdev)366 static int gab_remove(struct platform_device *pdev)
367 {
368 int chan;
369 struct gab *adc_bat = platform_get_drvdata(pdev);
370 struct gab_platform_data *pdata = adc_bat->pdata;
371
372 power_supply_unregister(adc_bat->psy);
373
374 if (gpio_is_valid(pdata->gpio_charge_finished)) {
375 free_irq(gpio_to_irq(pdata->gpio_charge_finished), adc_bat);
376 gpio_free(pdata->gpio_charge_finished);
377 }
378
379 for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
380 if (adc_bat->channel[chan])
381 iio_channel_release(adc_bat->channel[chan]);
382 }
383
384 kfree(adc_bat->psy_desc.properties);
385 cancel_delayed_work_sync(&adc_bat->bat_work);
386 return 0;
387 }
388
gab_suspend(struct device * dev)389 static int __maybe_unused gab_suspend(struct device *dev)
390 {
391 struct gab *adc_bat = dev_get_drvdata(dev);
392
393 cancel_delayed_work_sync(&adc_bat->bat_work);
394 adc_bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
395 return 0;
396 }
397
gab_resume(struct device * dev)398 static int __maybe_unused gab_resume(struct device *dev)
399 {
400 struct gab *adc_bat = dev_get_drvdata(dev);
401 struct gab_platform_data *pdata = adc_bat->pdata;
402 int delay;
403
404 delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
405
406 /* Schedule timer to check current status */
407 schedule_delayed_work(&adc_bat->bat_work,
408 msecs_to_jiffies(delay));
409 return 0;
410 }
411
412 static SIMPLE_DEV_PM_OPS(gab_pm_ops, gab_suspend, gab_resume);
413
414 static struct platform_driver gab_driver = {
415 .driver = {
416 .name = "generic-adc-battery",
417 .pm = &gab_pm_ops,
418 },
419 .probe = gab_probe,
420 .remove = gab_remove,
421 };
422 module_platform_driver(gab_driver);
423
424 MODULE_AUTHOR("anish kumar <anish198519851985@gmail.com>");
425 MODULE_DESCRIPTION("generic battery driver using IIO");
426 MODULE_LICENSE("GPL");
427