1*c82a2fbeSDmitry Osipenko // SPDX-License-Identifier: GPL-2.0+
2*c82a2fbeSDmitry Osipenko /*
3*c82a2fbeSDmitry Osipenko * Battery driver for Acer Iconia Tab A500.
4*c82a2fbeSDmitry Osipenko *
5*c82a2fbeSDmitry Osipenko * Copyright 2020 GRATE-driver project.
6*c82a2fbeSDmitry Osipenko *
7*c82a2fbeSDmitry Osipenko * Based on downstream driver from Acer Inc.
8*c82a2fbeSDmitry Osipenko * Based on NVIDIA Gas Gauge driver for SBS Compliant Batteries.
9*c82a2fbeSDmitry Osipenko *
10*c82a2fbeSDmitry Osipenko * Copyright (c) 2010, NVIDIA Corporation.
11*c82a2fbeSDmitry Osipenko */
12*c82a2fbeSDmitry Osipenko
13*c82a2fbeSDmitry Osipenko #include <linux/module.h>
14*c82a2fbeSDmitry Osipenko #include <linux/platform_device.h>
15*c82a2fbeSDmitry Osipenko #include <linux/power_supply.h>
16*c82a2fbeSDmitry Osipenko #include <linux/regmap.h>
17*c82a2fbeSDmitry Osipenko #include <linux/sched.h>
18*c82a2fbeSDmitry Osipenko #include <linux/slab.h>
19*c82a2fbeSDmitry Osipenko #include <linux/workqueue.h>
20*c82a2fbeSDmitry Osipenko
21*c82a2fbeSDmitry Osipenko enum {
22*c82a2fbeSDmitry Osipenko REG_CAPACITY,
23*c82a2fbeSDmitry Osipenko REG_VOLTAGE,
24*c82a2fbeSDmitry Osipenko REG_CURRENT,
25*c82a2fbeSDmitry Osipenko REG_DESIGN_CAPACITY,
26*c82a2fbeSDmitry Osipenko REG_TEMPERATURE,
27*c82a2fbeSDmitry Osipenko };
28*c82a2fbeSDmitry Osipenko
29*c82a2fbeSDmitry Osipenko #define EC_DATA(_reg, _psp) { \
30*c82a2fbeSDmitry Osipenko .psp = POWER_SUPPLY_PROP_ ## _psp, \
31*c82a2fbeSDmitry Osipenko .reg = _reg, \
32*c82a2fbeSDmitry Osipenko }
33*c82a2fbeSDmitry Osipenko
34*c82a2fbeSDmitry Osipenko static const struct battery_register {
35*c82a2fbeSDmitry Osipenko enum power_supply_property psp;
36*c82a2fbeSDmitry Osipenko unsigned int reg;
37*c82a2fbeSDmitry Osipenko } ec_data[] = {
38*c82a2fbeSDmitry Osipenko [REG_CAPACITY] = EC_DATA(0x00, CAPACITY),
39*c82a2fbeSDmitry Osipenko [REG_VOLTAGE] = EC_DATA(0x01, VOLTAGE_NOW),
40*c82a2fbeSDmitry Osipenko [REG_CURRENT] = EC_DATA(0x03, CURRENT_NOW),
41*c82a2fbeSDmitry Osipenko [REG_DESIGN_CAPACITY] = EC_DATA(0x08, CHARGE_FULL_DESIGN),
42*c82a2fbeSDmitry Osipenko [REG_TEMPERATURE] = EC_DATA(0x0a, TEMP),
43*c82a2fbeSDmitry Osipenko };
44*c82a2fbeSDmitry Osipenko
45*c82a2fbeSDmitry Osipenko static const enum power_supply_property a500_battery_properties[] = {
46*c82a2fbeSDmitry Osipenko POWER_SUPPLY_PROP_CAPACITY,
47*c82a2fbeSDmitry Osipenko POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
48*c82a2fbeSDmitry Osipenko POWER_SUPPLY_PROP_CURRENT_NOW,
49*c82a2fbeSDmitry Osipenko POWER_SUPPLY_PROP_PRESENT,
50*c82a2fbeSDmitry Osipenko POWER_SUPPLY_PROP_STATUS,
51*c82a2fbeSDmitry Osipenko POWER_SUPPLY_PROP_TECHNOLOGY,
52*c82a2fbeSDmitry Osipenko POWER_SUPPLY_PROP_TEMP,
53*c82a2fbeSDmitry Osipenko POWER_SUPPLY_PROP_VOLTAGE_NOW,
54*c82a2fbeSDmitry Osipenko };
55*c82a2fbeSDmitry Osipenko
56*c82a2fbeSDmitry Osipenko struct a500_battery {
57*c82a2fbeSDmitry Osipenko struct delayed_work poll_work;
58*c82a2fbeSDmitry Osipenko struct power_supply *psy;
59*c82a2fbeSDmitry Osipenko struct regmap *regmap;
60*c82a2fbeSDmitry Osipenko unsigned int capacity;
61*c82a2fbeSDmitry Osipenko };
62*c82a2fbeSDmitry Osipenko
a500_battery_update_capacity(struct a500_battery * bat)63*c82a2fbeSDmitry Osipenko static bool a500_battery_update_capacity(struct a500_battery *bat)
64*c82a2fbeSDmitry Osipenko {
65*c82a2fbeSDmitry Osipenko unsigned int capacity;
66*c82a2fbeSDmitry Osipenko int err;
67*c82a2fbeSDmitry Osipenko
68*c82a2fbeSDmitry Osipenko err = regmap_read(bat->regmap, ec_data[REG_CAPACITY].reg, &capacity);
69*c82a2fbeSDmitry Osipenko if (err)
70*c82a2fbeSDmitry Osipenko return false;
71*c82a2fbeSDmitry Osipenko
72*c82a2fbeSDmitry Osipenko /* capacity can be >100% even if max value is 100% */
73*c82a2fbeSDmitry Osipenko capacity = min(capacity, 100u);
74*c82a2fbeSDmitry Osipenko
75*c82a2fbeSDmitry Osipenko if (bat->capacity != capacity) {
76*c82a2fbeSDmitry Osipenko bat->capacity = capacity;
77*c82a2fbeSDmitry Osipenko return true;
78*c82a2fbeSDmitry Osipenko }
79*c82a2fbeSDmitry Osipenko
80*c82a2fbeSDmitry Osipenko return false;
81*c82a2fbeSDmitry Osipenko }
82*c82a2fbeSDmitry Osipenko
a500_battery_get_status(struct a500_battery * bat)83*c82a2fbeSDmitry Osipenko static int a500_battery_get_status(struct a500_battery *bat)
84*c82a2fbeSDmitry Osipenko {
85*c82a2fbeSDmitry Osipenko if (bat->capacity < 100) {
86*c82a2fbeSDmitry Osipenko if (power_supply_am_i_supplied(bat->psy))
87*c82a2fbeSDmitry Osipenko return POWER_SUPPLY_STATUS_CHARGING;
88*c82a2fbeSDmitry Osipenko else
89*c82a2fbeSDmitry Osipenko return POWER_SUPPLY_STATUS_DISCHARGING;
90*c82a2fbeSDmitry Osipenko }
91*c82a2fbeSDmitry Osipenko
92*c82a2fbeSDmitry Osipenko return POWER_SUPPLY_STATUS_FULL;
93*c82a2fbeSDmitry Osipenko }
94*c82a2fbeSDmitry Osipenko
a500_battery_unit_adjustment(struct device * dev,enum power_supply_property psp,union power_supply_propval * val)95*c82a2fbeSDmitry Osipenko static void a500_battery_unit_adjustment(struct device *dev,
96*c82a2fbeSDmitry Osipenko enum power_supply_property psp,
97*c82a2fbeSDmitry Osipenko union power_supply_propval *val)
98*c82a2fbeSDmitry Osipenko {
99*c82a2fbeSDmitry Osipenko const unsigned int base_unit_conversion = 1000;
100*c82a2fbeSDmitry Osipenko const unsigned int temp_kelvin_to_celsius = 2731;
101*c82a2fbeSDmitry Osipenko
102*c82a2fbeSDmitry Osipenko switch (psp) {
103*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
104*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_CURRENT_NOW:
105*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_VOLTAGE_NOW:
106*c82a2fbeSDmitry Osipenko val->intval *= base_unit_conversion;
107*c82a2fbeSDmitry Osipenko break;
108*c82a2fbeSDmitry Osipenko
109*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_TEMP:
110*c82a2fbeSDmitry Osipenko val->intval -= temp_kelvin_to_celsius;
111*c82a2fbeSDmitry Osipenko break;
112*c82a2fbeSDmitry Osipenko
113*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_PRESENT:
114*c82a2fbeSDmitry Osipenko val->intval = !!val->intval;
115*c82a2fbeSDmitry Osipenko break;
116*c82a2fbeSDmitry Osipenko
117*c82a2fbeSDmitry Osipenko default:
118*c82a2fbeSDmitry Osipenko dev_dbg(dev,
119*c82a2fbeSDmitry Osipenko "%s: no need for unit conversion %d\n", __func__, psp);
120*c82a2fbeSDmitry Osipenko }
121*c82a2fbeSDmitry Osipenko }
122*c82a2fbeSDmitry Osipenko
a500_battery_get_ec_data_index(struct device * dev,enum power_supply_property psp)123*c82a2fbeSDmitry Osipenko static int a500_battery_get_ec_data_index(struct device *dev,
124*c82a2fbeSDmitry Osipenko enum power_supply_property psp)
125*c82a2fbeSDmitry Osipenko {
126*c82a2fbeSDmitry Osipenko unsigned int i;
127*c82a2fbeSDmitry Osipenko
128*c82a2fbeSDmitry Osipenko /*
129*c82a2fbeSDmitry Osipenko * DESIGN_CAPACITY register always returns a non-zero value if
130*c82a2fbeSDmitry Osipenko * battery is connected and zero if disconnected, hence we'll use
131*c82a2fbeSDmitry Osipenko * it for judging the battery presence.
132*c82a2fbeSDmitry Osipenko */
133*c82a2fbeSDmitry Osipenko if (psp == POWER_SUPPLY_PROP_PRESENT)
134*c82a2fbeSDmitry Osipenko psp = POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN;
135*c82a2fbeSDmitry Osipenko
136*c82a2fbeSDmitry Osipenko for (i = 0; i < ARRAY_SIZE(ec_data); i++)
137*c82a2fbeSDmitry Osipenko if (psp == ec_data[i].psp)
138*c82a2fbeSDmitry Osipenko return i;
139*c82a2fbeSDmitry Osipenko
140*c82a2fbeSDmitry Osipenko dev_dbg(dev, "%s: invalid property %u\n", __func__, psp);
141*c82a2fbeSDmitry Osipenko
142*c82a2fbeSDmitry Osipenko return -EINVAL;
143*c82a2fbeSDmitry Osipenko }
144*c82a2fbeSDmitry Osipenko
a500_battery_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)145*c82a2fbeSDmitry Osipenko static int a500_battery_get_property(struct power_supply *psy,
146*c82a2fbeSDmitry Osipenko enum power_supply_property psp,
147*c82a2fbeSDmitry Osipenko union power_supply_propval *val)
148*c82a2fbeSDmitry Osipenko {
149*c82a2fbeSDmitry Osipenko struct a500_battery *bat = power_supply_get_drvdata(psy);
150*c82a2fbeSDmitry Osipenko struct device *dev = psy->dev.parent;
151*c82a2fbeSDmitry Osipenko int ret = 0;
152*c82a2fbeSDmitry Osipenko
153*c82a2fbeSDmitry Osipenko switch (psp) {
154*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_STATUS:
155*c82a2fbeSDmitry Osipenko val->intval = a500_battery_get_status(bat);
156*c82a2fbeSDmitry Osipenko break;
157*c82a2fbeSDmitry Osipenko
158*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_TECHNOLOGY:
159*c82a2fbeSDmitry Osipenko val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
160*c82a2fbeSDmitry Osipenko break;
161*c82a2fbeSDmitry Osipenko
162*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_CAPACITY:
163*c82a2fbeSDmitry Osipenko a500_battery_update_capacity(bat);
164*c82a2fbeSDmitry Osipenko val->intval = bat->capacity;
165*c82a2fbeSDmitry Osipenko break;
166*c82a2fbeSDmitry Osipenko
167*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
168*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_CURRENT_NOW:
169*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_VOLTAGE_NOW:
170*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_PRESENT:
171*c82a2fbeSDmitry Osipenko case POWER_SUPPLY_PROP_TEMP:
172*c82a2fbeSDmitry Osipenko ret = a500_battery_get_ec_data_index(dev, psp);
173*c82a2fbeSDmitry Osipenko if (ret < 0)
174*c82a2fbeSDmitry Osipenko break;
175*c82a2fbeSDmitry Osipenko
176*c82a2fbeSDmitry Osipenko ret = regmap_read(bat->regmap, ec_data[ret].reg, &val->intval);
177*c82a2fbeSDmitry Osipenko break;
178*c82a2fbeSDmitry Osipenko
179*c82a2fbeSDmitry Osipenko default:
180*c82a2fbeSDmitry Osipenko dev_err(dev, "%s: invalid property %u\n", __func__, psp);
181*c82a2fbeSDmitry Osipenko return -EINVAL;
182*c82a2fbeSDmitry Osipenko }
183*c82a2fbeSDmitry Osipenko
184*c82a2fbeSDmitry Osipenko if (!ret) {
185*c82a2fbeSDmitry Osipenko /* convert units to match requirements of power supply class */
186*c82a2fbeSDmitry Osipenko a500_battery_unit_adjustment(dev, psp, val);
187*c82a2fbeSDmitry Osipenko }
188*c82a2fbeSDmitry Osipenko
189*c82a2fbeSDmitry Osipenko dev_dbg(dev, "%s: property = %d, value = %x\n",
190*c82a2fbeSDmitry Osipenko __func__, psp, val->intval);
191*c82a2fbeSDmitry Osipenko
192*c82a2fbeSDmitry Osipenko /* return NODATA for properties if battery not presents */
193*c82a2fbeSDmitry Osipenko if (ret)
194*c82a2fbeSDmitry Osipenko return -ENODATA;
195*c82a2fbeSDmitry Osipenko
196*c82a2fbeSDmitry Osipenko return 0;
197*c82a2fbeSDmitry Osipenko }
198*c82a2fbeSDmitry Osipenko
a500_battery_poll_work(struct work_struct * work)199*c82a2fbeSDmitry Osipenko static void a500_battery_poll_work(struct work_struct *work)
200*c82a2fbeSDmitry Osipenko {
201*c82a2fbeSDmitry Osipenko struct a500_battery *bat;
202*c82a2fbeSDmitry Osipenko bool capacity_changed;
203*c82a2fbeSDmitry Osipenko
204*c82a2fbeSDmitry Osipenko bat = container_of(work, struct a500_battery, poll_work.work);
205*c82a2fbeSDmitry Osipenko capacity_changed = a500_battery_update_capacity(bat);
206*c82a2fbeSDmitry Osipenko
207*c82a2fbeSDmitry Osipenko if (capacity_changed)
208*c82a2fbeSDmitry Osipenko power_supply_changed(bat->psy);
209*c82a2fbeSDmitry Osipenko
210*c82a2fbeSDmitry Osipenko /* continuously send uevent notification */
211*c82a2fbeSDmitry Osipenko schedule_delayed_work(&bat->poll_work, 30 * HZ);
212*c82a2fbeSDmitry Osipenko }
213*c82a2fbeSDmitry Osipenko
214*c82a2fbeSDmitry Osipenko static const struct power_supply_desc a500_battery_desc = {
215*c82a2fbeSDmitry Osipenko .name = "ec-battery",
216*c82a2fbeSDmitry Osipenko .type = POWER_SUPPLY_TYPE_BATTERY,
217*c82a2fbeSDmitry Osipenko .properties = a500_battery_properties,
218*c82a2fbeSDmitry Osipenko .get_property = a500_battery_get_property,
219*c82a2fbeSDmitry Osipenko .num_properties = ARRAY_SIZE(a500_battery_properties),
220*c82a2fbeSDmitry Osipenko .external_power_changed = power_supply_changed,
221*c82a2fbeSDmitry Osipenko };
222*c82a2fbeSDmitry Osipenko
a500_battery_probe(struct platform_device * pdev)223*c82a2fbeSDmitry Osipenko static int a500_battery_probe(struct platform_device *pdev)
224*c82a2fbeSDmitry Osipenko {
225*c82a2fbeSDmitry Osipenko struct power_supply_config psy_cfg = {};
226*c82a2fbeSDmitry Osipenko struct a500_battery *bat;
227*c82a2fbeSDmitry Osipenko
228*c82a2fbeSDmitry Osipenko bat = devm_kzalloc(&pdev->dev, sizeof(*bat), GFP_KERNEL);
229*c82a2fbeSDmitry Osipenko if (!bat)
230*c82a2fbeSDmitry Osipenko return -ENOMEM;
231*c82a2fbeSDmitry Osipenko
232*c82a2fbeSDmitry Osipenko platform_set_drvdata(pdev, bat);
233*c82a2fbeSDmitry Osipenko
234*c82a2fbeSDmitry Osipenko psy_cfg.of_node = pdev->dev.parent->of_node;
235*c82a2fbeSDmitry Osipenko psy_cfg.drv_data = bat;
236*c82a2fbeSDmitry Osipenko
237*c82a2fbeSDmitry Osipenko bat->regmap = dev_get_regmap(pdev->dev.parent, "KB930");
238*c82a2fbeSDmitry Osipenko if (!bat->regmap)
239*c82a2fbeSDmitry Osipenko return -EINVAL;
240*c82a2fbeSDmitry Osipenko
241*c82a2fbeSDmitry Osipenko bat->psy = devm_power_supply_register_no_ws(&pdev->dev,
242*c82a2fbeSDmitry Osipenko &a500_battery_desc,
243*c82a2fbeSDmitry Osipenko &psy_cfg);
244*c82a2fbeSDmitry Osipenko if (IS_ERR(bat->psy))
245*c82a2fbeSDmitry Osipenko return dev_err_probe(&pdev->dev, PTR_ERR(bat->psy),
246*c82a2fbeSDmitry Osipenko "failed to register battery\n");
247*c82a2fbeSDmitry Osipenko
248*c82a2fbeSDmitry Osipenko INIT_DELAYED_WORK(&bat->poll_work, a500_battery_poll_work);
249*c82a2fbeSDmitry Osipenko schedule_delayed_work(&bat->poll_work, HZ);
250*c82a2fbeSDmitry Osipenko
251*c82a2fbeSDmitry Osipenko return 0;
252*c82a2fbeSDmitry Osipenko }
253*c82a2fbeSDmitry Osipenko
a500_battery_remove(struct platform_device * pdev)254*c82a2fbeSDmitry Osipenko static int a500_battery_remove(struct platform_device *pdev)
255*c82a2fbeSDmitry Osipenko {
256*c82a2fbeSDmitry Osipenko struct a500_battery *bat = dev_get_drvdata(&pdev->dev);
257*c82a2fbeSDmitry Osipenko
258*c82a2fbeSDmitry Osipenko cancel_delayed_work_sync(&bat->poll_work);
259*c82a2fbeSDmitry Osipenko
260*c82a2fbeSDmitry Osipenko return 0;
261*c82a2fbeSDmitry Osipenko }
262*c82a2fbeSDmitry Osipenko
a500_battery_suspend(struct device * dev)263*c82a2fbeSDmitry Osipenko static int __maybe_unused a500_battery_suspend(struct device *dev)
264*c82a2fbeSDmitry Osipenko {
265*c82a2fbeSDmitry Osipenko struct a500_battery *bat = dev_get_drvdata(dev);
266*c82a2fbeSDmitry Osipenko
267*c82a2fbeSDmitry Osipenko cancel_delayed_work_sync(&bat->poll_work);
268*c82a2fbeSDmitry Osipenko
269*c82a2fbeSDmitry Osipenko return 0;
270*c82a2fbeSDmitry Osipenko }
271*c82a2fbeSDmitry Osipenko
a500_battery_resume(struct device * dev)272*c82a2fbeSDmitry Osipenko static int __maybe_unused a500_battery_resume(struct device *dev)
273*c82a2fbeSDmitry Osipenko {
274*c82a2fbeSDmitry Osipenko struct a500_battery *bat = dev_get_drvdata(dev);
275*c82a2fbeSDmitry Osipenko
276*c82a2fbeSDmitry Osipenko schedule_delayed_work(&bat->poll_work, HZ);
277*c82a2fbeSDmitry Osipenko
278*c82a2fbeSDmitry Osipenko return 0;
279*c82a2fbeSDmitry Osipenko }
280*c82a2fbeSDmitry Osipenko
281*c82a2fbeSDmitry Osipenko static SIMPLE_DEV_PM_OPS(a500_battery_pm_ops,
282*c82a2fbeSDmitry Osipenko a500_battery_suspend, a500_battery_resume);
283*c82a2fbeSDmitry Osipenko
284*c82a2fbeSDmitry Osipenko static struct platform_driver a500_battery_driver = {
285*c82a2fbeSDmitry Osipenko .driver = {
286*c82a2fbeSDmitry Osipenko .name = "acer-a500-iconia-battery",
287*c82a2fbeSDmitry Osipenko .pm = &a500_battery_pm_ops,
288*c82a2fbeSDmitry Osipenko },
289*c82a2fbeSDmitry Osipenko .probe = a500_battery_probe,
290*c82a2fbeSDmitry Osipenko .remove = a500_battery_remove,
291*c82a2fbeSDmitry Osipenko };
292*c82a2fbeSDmitry Osipenko module_platform_driver(a500_battery_driver);
293*c82a2fbeSDmitry Osipenko
294*c82a2fbeSDmitry Osipenko MODULE_DESCRIPTION("Battery gauge driver for Acer Iconia Tab A500");
295*c82a2fbeSDmitry Osipenko MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
296*c82a2fbeSDmitry Osipenko MODULE_ALIAS("platform:acer-a500-iconia-battery");
297*c82a2fbeSDmitry Osipenko MODULE_LICENSE("GPL");
298