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
28 struct 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
gpio_charger_irq(int irq,void * devid)36 static 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
psy_to_gpio_charger(struct power_supply * psy)45 static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
46 {
47 return container_of(psy, struct gpio_charger, charger);
48 }
49
gpio_charger_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)50 static 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
68 static enum power_supply_property gpio_charger_properties[] = {
69 POWER_SUPPLY_PROP_ONLINE,
70 };
71
gpio_charger_probe(struct platform_device * pdev)72 static 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
144 err_gpio_free:
145 gpio_free(pdata->gpio);
146 err_free:
147 return ret;
148 }
149
gpio_charger_remove(struct platform_device * pdev)150 static 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
gpio_charger_suspend(struct device * dev)165 static 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
gpio_charger_resume(struct device * dev)176 static 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 (device_may_wakeup(dev) && 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
189 static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
190 gpio_charger_suspend, gpio_charger_resume);
191
192 static 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
202 module_platform_driver(gpio_charger_driver);
203
204 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
205 MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
206 MODULE_LICENSE("GPL");
207 MODULE_ALIAS("platform:gpio-charger");
208