1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Generic battery driver using IIO
4 * Copyright (C) 2012, Anish Kumar <yesanishhere@gmail.com>
5 * Copyright (c) 2023, Sebastian Reichel <sre@kernel.org>
6 */
7#include <linux/interrupt.h>
8#include <linux/platform_device.h>
9#include <linux/power_supply.h>
10#include <linux/gpio/consumer.h>
11#include <linux/err.h>
12#include <linux/timer.h>
13#include <linux/jiffies.h>
14#include <linux/errno.h>
15#include <linux/init.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/iio/consumer.h>
19#include <linux/iio/types.h>
20#include <linux/of.h>
21#include <linux/devm-helpers.h>
22
23#define JITTER_DEFAULT 10 /* hope 10ms is enough */
24
25enum gab_chan_type {
26 GAB_VOLTAGE = 0,
27 GAB_CURRENT,
28 GAB_POWER,
29 GAB_TEMP,
30 GAB_MAX_CHAN_TYPE
31};
32
33/*
34 * gab_chan_name suggests the standard channel names for commonly used
35 * channel types.
36 */
37static const char *const gab_chan_name[] = {
38 [GAB_VOLTAGE] = "voltage",
39 [GAB_CURRENT] = "current",
40 [GAB_POWER] = "power",
41 [GAB_TEMP] = "temperature",
42};
43
44struct gab {
45 struct power_supply *psy;
46 struct power_supply_desc psy_desc;
47 struct iio_channel *channel[GAB_MAX_CHAN_TYPE];
48 struct delayed_work bat_work;
49 int status;
50 struct gpio_desc *charge_finished;
51};
52
53static struct gab *to_generic_bat(struct power_supply *psy)
54{
55 return power_supply_get_drvdata(psy);
56}
57
58static void gab_ext_power_changed(struct power_supply *psy)
59{
60 struct gab *adc_bat = to_generic_bat(psy);
61
62 schedule_delayed_work(dwork: &adc_bat->bat_work, delay: msecs_to_jiffies(m: 0));
63}
64
65static const enum power_supply_property gab_props[] = {
66 POWER_SUPPLY_PROP_STATUS,
67};
68
69/*
70 * This properties are set based on the received platform data and this
71 * should correspond one-to-one with enum chan_type.
72 */
73static const enum power_supply_property gab_dyn_props[] = {
74 POWER_SUPPLY_PROP_VOLTAGE_NOW,
75 POWER_SUPPLY_PROP_CURRENT_NOW,
76 POWER_SUPPLY_PROP_POWER_NOW,
77 POWER_SUPPLY_PROP_TEMP,
78};
79
80static bool gab_charge_finished(struct gab *adc_bat)
81{
82 if (!adc_bat->charge_finished)
83 return false;
84 return gpiod_get_value(desc: adc_bat->charge_finished);
85}
86
87static int gab_read_channel(struct gab *adc_bat, enum gab_chan_type channel,
88 int *result)
89{
90 int ret;
91
92 ret = iio_read_channel_processed(chan: adc_bat->channel[channel], val: result);
93 if (ret < 0)
94 dev_err(&adc_bat->psy->dev, "read channel error: %d\n", ret);
95 else
96 *result *= 1000;
97
98 return ret;
99}
100
101static int gab_get_property(struct power_supply *psy,
102 enum power_supply_property psp, union power_supply_propval *val)
103{
104 struct gab *adc_bat = to_generic_bat(psy);
105
106 switch (psp) {
107 case POWER_SUPPLY_PROP_STATUS:
108 val->intval = adc_bat->status;
109 return 0;
110 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
111 return gab_read_channel(adc_bat, channel: GAB_VOLTAGE, result: &val->intval);
112 case POWER_SUPPLY_PROP_CURRENT_NOW:
113 return gab_read_channel(adc_bat, channel: GAB_CURRENT, result: &val->intval);
114 case POWER_SUPPLY_PROP_POWER_NOW:
115 return gab_read_channel(adc_bat, channel: GAB_POWER, result: &val->intval);
116 case POWER_SUPPLY_PROP_TEMP:
117 return gab_read_channel(adc_bat, channel: GAB_TEMP, result: &val->intval);
118 default:
119 return -EINVAL;
120 }
121}
122
123static void gab_work(struct work_struct *work)
124{
125 struct gab *adc_bat;
126 struct delayed_work *delayed_work;
127 int status;
128
129 delayed_work = to_delayed_work(work);
130 adc_bat = container_of(delayed_work, struct gab, bat_work);
131 status = adc_bat->status;
132
133 if (!power_supply_am_i_supplied(psy: adc_bat->psy))
134 adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
135 else if (gab_charge_finished(adc_bat))
136 adc_bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
137 else
138 adc_bat->status = POWER_SUPPLY_STATUS_CHARGING;
139
140 if (status != adc_bat->status)
141 power_supply_changed(psy: adc_bat->psy);
142}
143
144static irqreturn_t gab_charged(int irq, void *dev_id)
145{
146 struct gab *adc_bat = dev_id;
147
148 schedule_delayed_work(dwork: &adc_bat->bat_work,
149 delay: msecs_to_jiffies(JITTER_DEFAULT));
150
151 return IRQ_HANDLED;
152}
153
154static int gab_probe(struct platform_device *pdev)
155{
156 struct gab *adc_bat;
157 struct power_supply_desc *psy_desc;
158 struct power_supply_config psy_cfg = {};
159 enum power_supply_property *properties;
160 int ret = 0;
161 int chan;
162 int index = ARRAY_SIZE(gab_props);
163 bool any = false;
164
165 adc_bat = devm_kzalloc(dev: &pdev->dev, size: sizeof(*adc_bat), GFP_KERNEL);
166 if (!adc_bat)
167 return -ENOMEM;
168
169 psy_cfg.fwnode = dev_fwnode(&pdev->dev);
170 psy_cfg.drv_data = adc_bat;
171 psy_desc = &adc_bat->psy_desc;
172 psy_desc->name = dev_name(dev: &pdev->dev);
173
174 /* bootup default values for the battery */
175 adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
176 psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
177 psy_desc->get_property = gab_get_property;
178 psy_desc->external_power_changed = gab_ext_power_changed;
179
180 /*
181 * copying the static properties and allocating extra memory for holding
182 * the extra configurable properties received from platform data.
183 */
184 properties = devm_kcalloc(dev: &pdev->dev,
185 ARRAY_SIZE(gab_props) +
186 ARRAY_SIZE(gab_chan_name),
187 size: sizeof(*properties),
188 GFP_KERNEL);
189 if (!properties)
190 return -ENOMEM;
191
192 memcpy(properties, gab_props, sizeof(gab_props));
193
194 /*
195 * getting channel from iio and copying the battery properties
196 * based on the channel supported by consumer device.
197 */
198 for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
199 adc_bat->channel[chan] = devm_iio_channel_get(dev: &pdev->dev, consumer_channel: gab_chan_name[chan]);
200 if (IS_ERR(ptr: adc_bat->channel[chan])) {
201 ret = PTR_ERR(ptr: adc_bat->channel[chan]);
202 if (ret != -ENODEV)
203 return dev_err_probe(dev: &pdev->dev, err: ret, fmt: "Failed to get ADC channel %s\n", gab_chan_name[chan]);
204 adc_bat->channel[chan] = NULL;
205 } else if (adc_bat->channel[chan]) {
206 /* copying properties for supported channels only */
207 int index2;
208
209 for (index2 = 0; index2 < index; index2++) {
210 if (properties[index2] == gab_dyn_props[chan])
211 break; /* already known */
212 }
213 if (index2 == index) /* really new */
214 properties[index++] = gab_dyn_props[chan];
215 any = true;
216 }
217 }
218
219 /* none of the channels are supported so let's bail out */
220 if (!any)
221 return dev_err_probe(dev: &pdev->dev, err: -ENODEV, fmt: "Failed to get any ADC channel\n");
222
223 /*
224 * Total number of properties is equal to static properties
225 * plus the dynamic properties.Some properties may not be set
226 * as come channels may be not be supported by the device.So
227 * we need to take care of that.
228 */
229 psy_desc->properties = properties;
230 psy_desc->num_properties = index;
231
232 adc_bat->psy = devm_power_supply_register(parent: &pdev->dev, desc: psy_desc, cfg: &psy_cfg);
233 if (IS_ERR(ptr: adc_bat->psy))
234 return dev_err_probe(dev: &pdev->dev, err: PTR_ERR(ptr: adc_bat->psy), fmt: "Failed to register power-supply device\n");
235
236 ret = devm_delayed_work_autocancel(dev: &pdev->dev, w: &adc_bat->bat_work, worker: gab_work);
237 if (ret)
238 return dev_err_probe(dev: &pdev->dev, err: ret, fmt: "Failed to register delayed work\n");
239
240 adc_bat->charge_finished = devm_gpiod_get_optional(dev: &pdev->dev, con_id: "charged", flags: GPIOD_IN);
241 if (adc_bat->charge_finished) {
242 int irq;
243
244 irq = gpiod_to_irq(desc: adc_bat->charge_finished);
245 ret = devm_request_any_context_irq(dev: &pdev->dev, irq, handler: gab_charged,
246 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
247 devname: "battery charged", dev_id: adc_bat);
248 if (ret < 0)
249 return dev_err_probe(dev: &pdev->dev, err: ret, fmt: "Failed to register irq\n");
250 }
251
252 platform_set_drvdata(pdev, data: adc_bat);
253
254 /* Schedule timer to check current status */
255 schedule_delayed_work(dwork: &adc_bat->bat_work,
256 delay: msecs_to_jiffies(m: 0));
257 return 0;
258}
259
260static int __maybe_unused gab_suspend(struct device *dev)
261{
262 struct gab *adc_bat = dev_get_drvdata(dev);
263
264 cancel_delayed_work_sync(dwork: &adc_bat->bat_work);
265 adc_bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
266 return 0;
267}
268
269static int __maybe_unused gab_resume(struct device *dev)
270{
271 struct gab *adc_bat = dev_get_drvdata(dev);
272
273 /* Schedule timer to check current status */
274 schedule_delayed_work(dwork: &adc_bat->bat_work,
275 delay: msecs_to_jiffies(JITTER_DEFAULT));
276
277 return 0;
278}
279
280static SIMPLE_DEV_PM_OPS(gab_pm_ops, gab_suspend, gab_resume);
281
282static const struct of_device_id gab_match[] = {
283 { .compatible = "adc-battery" },
284 { }
285};
286MODULE_DEVICE_TABLE(of, gab_match);
287
288static struct platform_driver gab_driver = {
289 .driver = {
290 .name = "generic-adc-battery",
291 .pm = &gab_pm_ops,
292 .of_match_table = gab_match,
293 },
294 .probe = gab_probe,
295};
296module_platform_driver(gab_driver);
297
298MODULE_AUTHOR("anish kumar <yesanishhere@gmail.com>");
299MODULE_DESCRIPTION("generic battery driver using IIO");
300MODULE_LICENSE("GPL");
301

source code of linux/drivers/power/supply/generic-adc-battery.c