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1/*
2 * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
3 * Driver for chargers which report their online status through a GPIO pin
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 *
10 * You should have received a copy of the GNU General Public License along
11 * with this program; if not, write to the Free Software Foundation, Inc.,
12 * 675 Mass Ave, Cambridge, MA 02139, USA.
13 *
14 */
15
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
26#include <linux/power/gpio-charger.h>
27
28struct gpio_charger {
29 const struct gpio_charger_platform_data *pdata;
30 unsigned int irq;
31 bool wakeup_enabled;
32
33 struct power_supply charger;
34};
35
36static irqreturn_t gpio_charger_irq(int irq, void *devid)
37{
38 struct power_supply *charger = devid;
39
40 power_supply_changed(charger);
41
42 return IRQ_HANDLED;
43}
44
45static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
46{
47 return container_of(psy, struct gpio_charger, charger);
48}
49
50static int gpio_charger_get_property(struct power_supply *psy,
51 enum power_supply_property psp, union power_supply_propval *val)
52{
53 struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
54 const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
55
56 switch (psp) {
57 case POWER_SUPPLY_PROP_ONLINE:
58 val->intval = gpio_get_value_cansleep(pdata->gpio);
59 val->intval ^= pdata->gpio_active_low;
60 break;
61 default:
62 return -EINVAL;
63 }
64
65 return 0;
66}
67
68static enum power_supply_property gpio_charger_properties[] = {
69 POWER_SUPPLY_PROP_ONLINE,
70};
71
72static int gpio_charger_probe(struct platform_device *pdev)
73{
74 const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
75 struct gpio_charger *gpio_charger;
76 struct power_supply *charger;
77 int ret;
78 int irq;
79
80 if (!pdata) {
81 dev_err(&pdev->dev, "No platform data\n");
82 return -EINVAL;
83 }
84
85 if (!gpio_is_valid(pdata->gpio)) {
86 dev_err(&pdev->dev, "Invalid gpio pin\n");
87 return -EINVAL;
88 }
89
90 gpio_charger = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
91 GFP_KERNEL);
92 if (!gpio_charger) {
93 dev_err(&pdev->dev, "Failed to alloc driver structure\n");
94 return -ENOMEM;
95 }
96
97 charger = &gpio_charger->charger;
98
99 charger->name = pdata->name ? pdata->name : "gpio-charger";
100 charger->type = pdata->type;
101 charger->properties = gpio_charger_properties;
102 charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
103 charger->get_property = gpio_charger_get_property;
104 charger->supplied_to = pdata->supplied_to;
105 charger->num_supplicants = pdata->num_supplicants;
106
107 ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
108 if (ret) {
109 dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
110 goto err_free;
111 }
112 ret = gpio_direction_input(pdata->gpio);
113 if (ret) {
114 dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
115 goto err_gpio_free;
116 }
117
118 gpio_charger->pdata = pdata;
119
120 ret = power_supply_register(&pdev->dev, charger);
121 if (ret < 0) {
122 dev_err(&pdev->dev, "Failed to register power supply: %d\n",
123 ret);
124 goto err_gpio_free;
125 }
126
127 irq = gpio_to_irq(pdata->gpio);
128 if (irq > 0) {
129 ret = request_any_context_irq(irq, gpio_charger_irq,
130 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
131 dev_name(&pdev->dev), charger);
132 if (ret < 0)
133 dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
134 else
135 gpio_charger->irq = irq;
136 }
137
138 platform_set_drvdata(pdev, gpio_charger);
139
140 device_init_wakeup(&pdev->dev, 1);
141
142 return 0;
143
144err_gpio_free:
145 gpio_free(pdata->gpio);
146err_free:
147 return ret;
148}
149
150static int gpio_charger_remove(struct platform_device *pdev)
151{
152 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
153
154 if (gpio_charger->irq)
155 free_irq(gpio_charger->irq, &gpio_charger->charger);
156
157 power_supply_unregister(&gpio_charger->charger);
158
159 gpio_free(gpio_charger->pdata->gpio);
160
161 return 0;
162}
163
164#ifdef CONFIG_PM_SLEEP
165static int gpio_charger_suspend(struct device *dev)
166{
167 struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
168
169 if (device_may_wakeup(dev))
170 gpio_charger->wakeup_enabled =
171 enable_irq_wake(gpio_charger->irq);
172
173 return 0;
174}
175
176static int gpio_charger_resume(struct device *dev)
177{
178 struct platform_device *pdev = to_platform_device(dev);
179 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
180
181 if (gpio_charger->wakeup_enabled)
182 disable_irq_wake(gpio_charger->irq);
183 power_supply_changed(&gpio_charger->charger);
184
185 return 0;
186}
187#endif
188
189static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
190 gpio_charger_suspend, gpio_charger_resume);
191
192static struct platform_driver gpio_charger_driver = {
193 .probe = gpio_charger_probe,
194 .remove = gpio_charger_remove,
195 .driver = {
196 .name = "gpio-charger",
197 .owner = THIS_MODULE,
198 .pm = &gpio_charger_pm_ops,
199 },
200};
201
202module_platform_driver(gpio_charger_driver);
203
204MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
205MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
206MODULE_LICENSE("GPL");
207MODULE_ALIAS("platform:gpio-charger");
1/*
2 * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
3 * Driver for chargers which report their online status through a GPIO pin
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 *
10 * You should have received a copy of the GNU General Public License along
11 * with this program; if not, write to the Free Software Foundation, Inc.,
12 * 675 Mass Ave, Cambridge, MA 02139, USA.
13 *
14 */
15
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/of_gpio.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};
38
39static irqreturn_t gpio_charger_irq(int irq, void *devid)
40{
41 struct power_supply *charger = devid;
42
43 power_supply_changed(charger);
44
45 return IRQ_HANDLED;
46}
47
48static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
49{
50 return power_supply_get_drvdata(psy);
51}
52
53static int gpio_charger_get_property(struct power_supply *psy,
54 enum power_supply_property psp, union power_supply_propval *val)
55{
56 struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
57 const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
58
59 switch (psp) {
60 case POWER_SUPPLY_PROP_ONLINE:
61 val->intval = !!gpio_get_value_cansleep(pdata->gpio);
62 val->intval ^= pdata->gpio_active_low;
63 break;
64 default:
65 return -EINVAL;
66 }
67
68 return 0;
69}
70
71static enum power_supply_property gpio_charger_properties[] = {
72 POWER_SUPPLY_PROP_ONLINE,
73};
74
75static
76struct gpio_charger_platform_data *gpio_charger_parse_dt(struct device *dev)
77{
78 struct device_node *np = dev->of_node;
79 struct gpio_charger_platform_data *pdata;
80 const char *chargetype;
81 enum of_gpio_flags flags;
82 int ret;
83
84 if (!np)
85 return ERR_PTR(-ENOENT);
86
87 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
88 if (!pdata)
89 return ERR_PTR(-ENOMEM);
90
91 pdata->name = np->name;
92
93 pdata->gpio = of_get_gpio_flags(np, 0, &flags);
94 if (pdata->gpio < 0) {
95 if (pdata->gpio != -EPROBE_DEFER)
96 dev_err(dev, "could not get charger gpio\n");
97 return ERR_PTR(pdata->gpio);
98 }
99
100 pdata->gpio_active_low = !!(flags & OF_GPIO_ACTIVE_LOW);
101
102 pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
103 ret = of_property_read_string(np, "charger-type", &chargetype);
104 if (ret >= 0) {
105 if (!strncmp("unknown", chargetype, 7))
106 pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
107 else if (!strncmp("battery", chargetype, 7))
108 pdata->type = POWER_SUPPLY_TYPE_BATTERY;
109 else if (!strncmp("ups", chargetype, 3))
110 pdata->type = POWER_SUPPLY_TYPE_UPS;
111 else if (!strncmp("mains", chargetype, 5))
112 pdata->type = POWER_SUPPLY_TYPE_MAINS;
113 else if (!strncmp("usb-sdp", chargetype, 7))
114 pdata->type = POWER_SUPPLY_TYPE_USB;
115 else if (!strncmp("usb-dcp", chargetype, 7))
116 pdata->type = POWER_SUPPLY_TYPE_USB_DCP;
117 else if (!strncmp("usb-cdp", chargetype, 7))
118 pdata->type = POWER_SUPPLY_TYPE_USB_CDP;
119 else if (!strncmp("usb-aca", chargetype, 7))
120 pdata->type = POWER_SUPPLY_TYPE_USB_ACA;
121 else
122 dev_warn(dev, "unknown charger type %s\n", chargetype);
123 }
124
125 return pdata;
126}
127
128static int gpio_charger_probe(struct platform_device *pdev)
129{
130 const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
131 struct power_supply_config psy_cfg = {};
132 struct gpio_charger *gpio_charger;
133 struct power_supply_desc *charger_desc;
134 int ret;
135 int irq;
136
137 if (!pdata) {
138 pdata = gpio_charger_parse_dt(&pdev->dev);
139 if (IS_ERR(pdata)) {
140 ret = PTR_ERR(pdata);
141 if (ret != -EPROBE_DEFER)
142 dev_err(&pdev->dev, "No platform data\n");
143 return ret;
144 }
145 }
146
147 if (!gpio_is_valid(pdata->gpio)) {
148 dev_err(&pdev->dev, "Invalid gpio pin\n");
149 return -EINVAL;
150 }
151
152 gpio_charger = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
153 GFP_KERNEL);
154 if (!gpio_charger) {
155 dev_err(&pdev->dev, "Failed to alloc driver structure\n");
156 return -ENOMEM;
157 }
158
159 charger_desc = &gpio_charger->charger_desc;
160
161 charger_desc->name = pdata->name ? pdata->name : "gpio-charger";
162 charger_desc->type = pdata->type;
163 charger_desc->properties = gpio_charger_properties;
164 charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties);
165 charger_desc->get_property = gpio_charger_get_property;
166
167 psy_cfg.supplied_to = pdata->supplied_to;
168 psy_cfg.num_supplicants = pdata->num_supplicants;
169 psy_cfg.of_node = pdev->dev.of_node;
170 psy_cfg.drv_data = gpio_charger;
171
172 ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
173 if (ret) {
174 dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
175 goto err_free;
176 }
177 ret = gpio_direction_input(pdata->gpio);
178 if (ret) {
179 dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
180 goto err_gpio_free;
181 }
182
183 gpio_charger->pdata = pdata;
184
185 gpio_charger->charger = power_supply_register(&pdev->dev,
186 charger_desc, &psy_cfg);
187 if (IS_ERR(gpio_charger->charger)) {
188 ret = PTR_ERR(gpio_charger->charger);
189 dev_err(&pdev->dev, "Failed to register power supply: %d\n",
190 ret);
191 goto err_gpio_free;
192 }
193
194 irq = gpio_to_irq(pdata->gpio);
195 if (irq > 0) {
196 ret = request_any_context_irq(irq, gpio_charger_irq,
197 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
198 dev_name(&pdev->dev), gpio_charger->charger);
199 if (ret < 0)
200 dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
201 else
202 gpio_charger->irq = irq;
203 }
204
205 platform_set_drvdata(pdev, gpio_charger);
206
207 device_init_wakeup(&pdev->dev, 1);
208
209 return 0;
210
211err_gpio_free:
212 gpio_free(pdata->gpio);
213err_free:
214 return ret;
215}
216
217static int gpio_charger_remove(struct platform_device *pdev)
218{
219 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
220
221 if (gpio_charger->irq)
222 free_irq(gpio_charger->irq, gpio_charger->charger);
223
224 power_supply_unregister(gpio_charger->charger);
225
226 gpio_free(gpio_charger->pdata->gpio);
227
228 return 0;
229}
230
231#ifdef CONFIG_PM_SLEEP
232static int gpio_charger_suspend(struct device *dev)
233{
234 struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
235
236 if (device_may_wakeup(dev))
237 gpio_charger->wakeup_enabled =
238 !enable_irq_wake(gpio_charger->irq);
239
240 return 0;
241}
242
243static int gpio_charger_resume(struct device *dev)
244{
245 struct platform_device *pdev = to_platform_device(dev);
246 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
247
248 if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
249 disable_irq_wake(gpio_charger->irq);
250 power_supply_changed(gpio_charger->charger);
251
252 return 0;
253}
254#endif
255
256static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
257 gpio_charger_suspend, gpio_charger_resume);
258
259static const struct of_device_id gpio_charger_match[] = {
260 { .compatible = "gpio-charger" },
261 { }
262};
263MODULE_DEVICE_TABLE(of, gpio_charger_match);
264
265static struct platform_driver gpio_charger_driver = {
266 .probe = gpio_charger_probe,
267 .remove = gpio_charger_remove,
268 .driver = {
269 .name = "gpio-charger",
270 .pm = &gpio_charger_pm_ops,
271 .of_match_table = gpio_charger_match,
272 },
273};
274
275module_platform_driver(gpio_charger_driver);
276
277MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
278MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
279MODULE_LICENSE("GPL");
280MODULE_ALIAS("platform:gpio-charger");