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
32 struct power_supply charger;
33 };
34
gpio_charger_irq(int irq,void * devid)35 static irqreturn_t gpio_charger_irq(int irq, void *devid)
36 {
37 struct power_supply *charger = devid;
38
39 power_supply_changed(charger);
40
41 return IRQ_HANDLED;
42 }
43
psy_to_gpio_charger(struct power_supply * psy)44 static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
45 {
46 return container_of(psy, struct gpio_charger, charger);
47 }
48
gpio_charger_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)49 static int gpio_charger_get_property(struct power_supply *psy,
50 enum power_supply_property psp, union power_supply_propval *val)
51 {
52 struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
53 const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
54
55 switch (psp) {
56 case POWER_SUPPLY_PROP_ONLINE:
57 val->intval = gpio_get_value_cansleep(pdata->gpio);
58 val->intval ^= pdata->gpio_active_low;
59 break;
60 default:
61 return -EINVAL;
62 }
63
64 return 0;
65 }
66
67 static enum power_supply_property gpio_charger_properties[] = {
68 POWER_SUPPLY_PROP_ONLINE,
69 };
70
gpio_charger_probe(struct platform_device * pdev)71 static int gpio_charger_probe(struct platform_device *pdev)
72 {
73 const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
74 struct gpio_charger *gpio_charger;
75 struct power_supply *charger;
76 int ret;
77 int irq;
78
79 if (!pdata) {
80 dev_err(&pdev->dev, "No platform data\n");
81 return -EINVAL;
82 }
83
84 if (!gpio_is_valid(pdata->gpio)) {
85 dev_err(&pdev->dev, "Invalid gpio pin\n");
86 return -EINVAL;
87 }
88
89 gpio_charger = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
90 GFP_KERNEL);
91 if (!gpio_charger) {
92 dev_err(&pdev->dev, "Failed to alloc driver structure\n");
93 return -ENOMEM;
94 }
95
96 charger = &gpio_charger->charger;
97
98 charger->name = pdata->name ? pdata->name : "gpio-charger";
99 charger->type = pdata->type;
100 charger->properties = gpio_charger_properties;
101 charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
102 charger->get_property = gpio_charger_get_property;
103 charger->supplied_to = pdata->supplied_to;
104 charger->num_supplicants = pdata->num_supplicants;
105
106 ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
107 if (ret) {
108 dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
109 goto err_free;
110 }
111 ret = gpio_direction_input(pdata->gpio);
112 if (ret) {
113 dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
114 goto err_gpio_free;
115 }
116
117 gpio_charger->pdata = pdata;
118
119 ret = power_supply_register(&pdev->dev, charger);
120 if (ret < 0) {
121 dev_err(&pdev->dev, "Failed to register power supply: %d\n",
122 ret);
123 goto err_gpio_free;
124 }
125
126 irq = gpio_to_irq(pdata->gpio);
127 if (irq > 0) {
128 ret = request_any_context_irq(irq, gpio_charger_irq,
129 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
130 dev_name(&pdev->dev), charger);
131 if (ret < 0)
132 dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
133 else
134 gpio_charger->irq = irq;
135 }
136
137 platform_set_drvdata(pdev, gpio_charger);
138
139 return 0;
140
141 err_gpio_free:
142 gpio_free(pdata->gpio);
143 err_free:
144 return ret;
145 }
146
gpio_charger_remove(struct platform_device * pdev)147 static int gpio_charger_remove(struct platform_device *pdev)
148 {
149 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
150
151 if (gpio_charger->irq)
152 free_irq(gpio_charger->irq, &gpio_charger->charger);
153
154 power_supply_unregister(&gpio_charger->charger);
155
156 gpio_free(gpio_charger->pdata->gpio);
157
158 platform_set_drvdata(pdev, NULL);
159
160 return 0;
161 }
162
163 #ifdef CONFIG_PM_SLEEP
gpio_charger_resume(struct device * dev)164 static int gpio_charger_resume(struct device *dev)
165 {
166 struct platform_device *pdev = to_platform_device(dev);
167 struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
168
169 power_supply_changed(&gpio_charger->charger);
170
171 return 0;
172 }
173 #endif
174
175 static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops, NULL, gpio_charger_resume);
176
177 static struct platform_driver gpio_charger_driver = {
178 .probe = gpio_charger_probe,
179 .remove = gpio_charger_remove,
180 .driver = {
181 .name = "gpio-charger",
182 .owner = THIS_MODULE,
183 .pm = &gpio_charger_pm_ops,
184 },
185 };
186
187 module_platform_driver(gpio_charger_driver);
188
189 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
190 MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
191 MODULE_LICENSE("GPL");
192 MODULE_ALIAS("platform:gpio-charger");
193