1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16#include <linux/delay.h>
17#include <linux/err.h>
18#include <linux/gpio/consumer.h>
19#include <linux/iio/consumer.h>
20#include <linux/iio/types.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/of_device.h>
24#include <linux/platform_device.h>
25#include <linux/power_supply.h>
26
27struct lego_ev3_battery {
28 struct iio_channel *iio_v;
29 struct iio_channel *iio_i;
30 struct gpio_desc *rechargeable_gpio;
31 struct power_supply *psy;
32 int technology;
33 int v_max;
34 int v_min;
35};
36
37static int lego_ev3_battery_get_property(struct power_supply *psy,
38 enum power_supply_property psp,
39 union power_supply_propval *val)
40{
41 struct lego_ev3_battery *batt = power_supply_get_drvdata(psy);
42 int val2;
43
44 switch (psp) {
45 case POWER_SUPPLY_PROP_TECHNOLOGY:
46 val->intval = batt->technology;
47 break;
48 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
49
50 iio_read_channel_processed(batt->iio_v, &val->intval);
51 val->intval *= 2000;
52 val->intval += 200000;
53
54 iio_read_channel_processed(batt->iio_i, &val2);
55 val2 *= 1000;
56 val2 /= 15;
57 val->intval += val2;
58 break;
59 case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
60 val->intval = batt->v_max;
61 break;
62 case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
63 val->intval = batt->v_min;
64 break;
65 case POWER_SUPPLY_PROP_CURRENT_NOW:
66
67 iio_read_channel_processed(batt->iio_i, &val->intval);
68 val->intval *= 20000;
69 val->intval /= 15;
70 break;
71 case POWER_SUPPLY_PROP_SCOPE:
72 val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
73 break;
74 default:
75 return -EINVAL;
76 }
77
78 return 0;
79}
80
81static int lego_ev3_battery_set_property(struct power_supply *psy,
82 enum power_supply_property psp,
83 const union power_supply_propval *val)
84{
85 struct lego_ev3_battery *batt = power_supply_get_drvdata(psy);
86
87 switch (psp) {
88 case POWER_SUPPLY_PROP_TECHNOLOGY:
89
90
91
92
93
94
95
96
97 if (batt->technology != POWER_SUPPLY_TECHNOLOGY_UNKNOWN)
98 return -EINVAL;
99 switch (val->intval) {
100 case POWER_SUPPLY_TECHNOLOGY_NiMH:
101 batt->technology = POWER_SUPPLY_TECHNOLOGY_NiMH;
102 batt->v_max = 7800000;
103 batt->v_min = 5400000;
104 break;
105 default:
106 return -EINVAL;
107 }
108 break;
109 default:
110 return -EINVAL;
111 }
112
113 return 0;
114}
115
116static int lego_ev3_battery_property_is_writeable(struct power_supply *psy,
117 enum power_supply_property psp)
118{
119 struct lego_ev3_battery *batt = power_supply_get_drvdata(psy);
120
121 return psp == POWER_SUPPLY_PROP_TECHNOLOGY &&
122 batt->technology == POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
123}
124
125static enum power_supply_property lego_ev3_battery_props[] = {
126 POWER_SUPPLY_PROP_TECHNOLOGY,
127 POWER_SUPPLY_PROP_VOLTAGE_NOW,
128 POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
129 POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
130 POWER_SUPPLY_PROP_CURRENT_NOW,
131 POWER_SUPPLY_PROP_SCOPE,
132};
133
134static const struct power_supply_desc lego_ev3_battery_desc = {
135 .name = "lego-ev3-battery",
136 .type = POWER_SUPPLY_TYPE_BATTERY,
137 .properties = lego_ev3_battery_props,
138 .num_properties = ARRAY_SIZE(lego_ev3_battery_props),
139 .get_property = lego_ev3_battery_get_property,
140 .set_property = lego_ev3_battery_set_property,
141 .property_is_writeable = lego_ev3_battery_property_is_writeable,
142};
143
144static int lego_ev3_battery_probe(struct platform_device *pdev)
145{
146 struct device *dev = &pdev->dev;
147 struct lego_ev3_battery *batt;
148 struct power_supply_config psy_cfg = {};
149 int err;
150
151 batt = devm_kzalloc(dev, sizeof(*batt), GFP_KERNEL);
152 if (!batt)
153 return -ENOMEM;
154
155 platform_set_drvdata(pdev, batt);
156
157 batt->iio_v = devm_iio_channel_get(dev, "voltage");
158 err = PTR_ERR_OR_ZERO(batt->iio_v);
159 if (err) {
160 if (err != -EPROBE_DEFER)
161 dev_err(dev, "Failed to get voltage iio channel\n");
162 return err;
163 }
164
165 batt->iio_i = devm_iio_channel_get(dev, "current");
166 err = PTR_ERR_OR_ZERO(batt->iio_i);
167 if (err) {
168 if (err != -EPROBE_DEFER)
169 dev_err(dev, "Failed to get current iio channel\n");
170 return err;
171 }
172
173 batt->rechargeable_gpio = devm_gpiod_get(dev, "rechargeable", GPIOD_IN);
174 err = PTR_ERR_OR_ZERO(batt->rechargeable_gpio);
175 if (err) {
176 if (err != -EPROBE_DEFER)
177 dev_err(dev, "Failed to get rechargeable gpio\n");
178 return err;
179 }
180
181
182
183
184
185 if (gpiod_get_value(batt->rechargeable_gpio)) {
186
187 batt->technology = POWER_SUPPLY_TECHNOLOGY_LION;
188 batt->v_max = 84000000;
189 batt->v_min = 60000000;
190 } else {
191
192 batt->technology = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
193 batt->v_max = 90000000;
194 batt->v_min = 48000000;
195 }
196
197 psy_cfg.of_node = pdev->dev.of_node;
198 psy_cfg.drv_data = batt;
199
200 batt->psy = devm_power_supply_register(dev, &lego_ev3_battery_desc,
201 &psy_cfg);
202 err = PTR_ERR_OR_ZERO(batt->psy);
203 if (err) {
204 dev_err(dev, "failed to register power supply\n");
205 return err;
206 }
207
208 return 0;
209}
210
211static const struct of_device_id of_lego_ev3_battery_match[] = {
212 { .compatible = "lego,ev3-battery", },
213 { }
214};
215MODULE_DEVICE_TABLE(of, of_lego_ev3_battery_match);
216
217static struct platform_driver lego_ev3_battery_driver = {
218 .driver = {
219 .name = "lego-ev3-battery",
220 .of_match_table = of_lego_ev3_battery_match,
221 },
222 .probe = lego_ev3_battery_probe,
223};
224module_platform_driver(lego_ev3_battery_driver);
225
226MODULE_LICENSE("GPL");
227MODULE_AUTHOR("David Lechner <david@lechnology.com>");
228MODULE_DESCRIPTION("LEGO MINDSTORMS EV3 Battery Driver");
229
