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16#include <linux/device.h>
17#include <linux/gpio.h>
18#include <linux/init.h>
19#include <linux/interrupt.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/platform_device.h>
23#include <linux/power_supply.h>
24#include <linux/slab.h>
25#include <linux/of.h>
26#include <linux/gpio/consumer.h>
27
28#include <linux/power/gpio-charger.h>
29
30struct gpio_charger {
31 const struct gpio_charger_platform_data *pdata;
32 unsigned int irq;
33 bool wakeup_enabled;
34
35 struct power_supply *charger;
36 struct power_supply_desc charger_desc;
37 struct gpio_desc *gpiod;
38 bool legacy_gpio_requested;
39};
40
41static irqreturn_t gpio_charger_irq(int irq, void *devid)
42{
43 struct power_supply *charger = devid;
44
45 power_supply_changed(charger);
46
47 return IRQ_HANDLED;
48}
49
50static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
51{
52 return power_supply_get_drvdata(psy);
53}
54
55static int gpio_charger_get_property(struct power_supply *psy,
56 enum power_supply_property psp, union power_supply_propval *val)
57{
58 struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
59 const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
60
61 switch (psp) {
62 case POWER_SUPPLY_PROP_ONLINE:
63 val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
64
65 val->intval ^= pdata->gpio_active_low;
66 break;
67 default:
68 return -EINVAL;
69 }
70
71 return 0;
72}
73
74static enum power_supply_property gpio_charger_properties[] = {
75 POWER_SUPPLY_PROP_ONLINE,
76};
77
78static
79struct gpio_charger_platform_data *gpio_charger_parse_dt(struct device *dev)
80{
81 struct device_node *np = dev->of_node;
82 struct gpio_charger_platform_data *pdata;
83 const char *chargetype;
84 int ret;
85
86 if (!np)
87 return ERR_PTR(-ENOENT);
88
89 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
90 if (!pdata)
91 return ERR_PTR(-ENOMEM);
92
93 pdata->name = np->name;
94 pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
95 ret = of_property_read_string(np, "charger-type", &chargetype);
96 if (ret >= 0) {
97 if (!strncmp("unknown", chargetype, 7))
98 pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
99 else if (!strncmp("battery", chargetype, 7))
100 pdata->type = POWER_SUPPLY_TYPE_BATTERY;
101 else if (!strncmp("ups", chargetype, 3))
102 pdata->type = POWER_SUPPLY_TYPE_UPS;
103 else if (!strncmp("mains", chargetype, 5))
104 pdata->type = POWER_SUPPLY_TYPE_MAINS;
105 else if (!strncmp("usb-sdp", chargetype, 7))
106 pdata->type = POWER_SUPPLY_TYPE_USB;
107 else if (!strncmp("usb-dcp", chargetype, 7))
108 pdata->type = POWER_SUPPLY_TYPE_USB_DCP;
109 else if (!strncmp("usb-cdp", chargetype, 7))
110 pdata->type = POWER_SUPPLY_TYPE_USB_CDP;
111 else if (!strncmp("usb-aca", chargetype, 7))
112 pdata->type = POWER_SUPPLY_TYPE_USB_ACA;
113 else
114 dev_warn(dev, "unknown charger type %s\n", chargetype);
115 }
116
117 return pdata;
118}
119
120static int gpio_charger_probe(struct platform_device *pdev)
121{
122 const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
123 struct power_supply_config psy_cfg = {};
124 struct gpio_charger *gpio_charger;
125 struct power_supply_desc *charger_desc;
126 int ret;
127 int irq;
128
129 if (!pdata) {
130 pdata = gpio_charger_parse_dt(&pdev->dev);
131 if (IS_ERR(pdata)) {
132 ret = PTR_ERR(pdata);
133 if (ret != -EPROBE_DEFER)
134 dev_err(&pdev->dev, "No platform data\n");
135 return ret;
136 }
137 }
138
139 gpio_charger = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
140 GFP_KERNEL);
141 if (!gpio_charger) {
142 dev_err(&pdev->dev, "Failed to alloc driver structure\n");
143 return -ENOMEM;
144 }
145
146
147
148
149
150 gpio_charger->gpiod = devm_gpiod_get(&pdev->dev, NULL, GPIOD_IN);
151
152
153
154
155
156 if (IS_ERR(gpio_charger->gpiod) && !pdev->dev.of_node) {
157
158 if (!gpio_is_valid(pdata->gpio)) {
159 dev_err(&pdev->dev, "Invalid gpio pin in pdata\n");
160 return -EINVAL;
161 }
162 ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
163 if (ret) {
164 dev_err(&pdev->dev, "Failed to request gpio pin: %d\n",
165 ret);
166 return ret;
167 }
168 gpio_charger->legacy_gpio_requested = true;
169 ret = gpio_direction_input(pdata->gpio);
170 if (ret) {
171 dev_err(&pdev->dev, "Failed to set gpio to input: %d\n",
172 ret);
173 goto err_gpio_free;
174 }
175
176 gpio_charger->gpiod = gpio_to_desc(pdata->gpio);
177 } else if (IS_ERR(gpio_charger->gpiod)) {
178
179 if (PTR_ERR(gpio_charger->gpiod) == -EPROBE_DEFER)
180 return -EPROBE_DEFER;
181 dev_err(&pdev->dev, "error getting GPIO descriptor\n");
182 return PTR_ERR(gpio_charger->gpiod);
183 }
184
185 charger_desc = &gpio_charger->charger_desc;
186
187 charger_desc->name = pdata->name ? pdata->name : "gpio-charger";
188 charger_desc->type = pdata->type;
189 charger_desc->properties = gpio_charger_properties;
190 charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties);
191 charger_desc->get_property = gpio_charger_get_property;
192
193 psy_cfg.supplied_to = pdata->supplied_to;
194 psy_cfg.num_supplicants = pdata->num_supplicants;
195 psy_cfg.of_node = pdev->dev.of_node;
196 psy_cfg.drv_data = gpio_charger;
197
198 gpio_charger->pdata = pdata;
199
200 gpio_charger->charger = power_supply_register(&pdev->dev,
201 charger_desc, &psy_cfg);
202 if (IS_ERR(gpio_charger->charger)) {
203 ret = PTR_ERR(gpio_charger->charger);
204 dev_err(&pdev->dev, "Failed to register power supply: %d\n",
205 ret);
206 goto err_gpio_free;
207 }
208
209 irq = gpiod_to_irq(gpio_charger->gpiod);
210 if (irq > 0) {
211 ret = request_any_context_irq(irq, gpio_charger_irq,
212 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
213 dev_name(&pdev->dev), gpio_charger->charger);
214 if (ret < 0)
215 dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
216 else
217 gpio_charger->irq = irq;
218 }
219
220 platform_set_drvdata(pdev, gpio_charger);
221
222 device_init_wakeup(&pdev->dev, 1);
223
224 return 0;
225
226err_gpio_free:
227 if (gpio_charger->legacy_gpio_requested)
228 gpio_free(pdata->gpio);
229 return ret;
230}
231
232static int gpio_charger_remove(struct platform_device *pdev)
233{
234 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
235
236 if (gpio_charger->irq)
237 free_irq(gpio_charger->irq, gpio_charger->charger);
238
239 power_supply_unregister(gpio_charger->charger);
240
241 if (gpio_charger->legacy_gpio_requested)
242 gpio_free(gpio_charger->pdata->gpio);
243
244 return 0;
245}
246
247#ifdef CONFIG_PM_SLEEP
248static int gpio_charger_suspend(struct device *dev)
249{
250 struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
251
252 if (device_may_wakeup(dev))
253 gpio_charger->wakeup_enabled =
254 !enable_irq_wake(gpio_charger->irq);
255
256 return 0;
257}
258
259static int gpio_charger_resume(struct device *dev)
260{
261 struct platform_device *pdev = to_platform_device(dev);
262 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
263
264 if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
265 disable_irq_wake(gpio_charger->irq);
266 power_supply_changed(gpio_charger->charger);
267
268 return 0;
269}
270#endif
271
272static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
273 gpio_charger_suspend, gpio_charger_resume);
274
275static const struct of_device_id gpio_charger_match[] = {
276 { .compatible = "gpio-charger" },
277 { }
278};
279MODULE_DEVICE_TABLE(of, gpio_charger_match);
280
281static struct platform_driver gpio_charger_driver = {
282 .probe = gpio_charger_probe,
283 .remove = gpio_charger_remove,
284 .driver = {
285 .name = "gpio-charger",
286 .pm = &gpio_charger_pm_ops,
287 .of_match_table = gpio_charger_match,
288 },
289};
290
291module_platform_driver(gpio_charger_driver);
292
293MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
294MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
295MODULE_LICENSE("GPL");
296MODULE_ALIAS("platform:gpio-charger");
297
