tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
4 * Driver for chargers which report their online status through a GPIO pin
5 */
6
7#include <linux/device.h>
8#include <linux/gpio.h> /* For legacy platform data */
9#include <linux/init.h>
10#include <linux/interrupt.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/power_supply.h>
15#include <linux/slab.h>
16#include <linux/of.h>
17#include <linux/gpio/consumer.h>
18
19#include <linux/power/gpio-charger.h>
20
21struct gpio_charger {
22 unsigned int irq;
23 unsigned int charge_status_irq;
24 bool wakeup_enabled;
25
26 struct power_supply *charger;
27 struct power_supply_desc charger_desc;
28 struct gpio_desc *gpiod;
29 struct gpio_desc *charge_status;
30};
31
32static irqreturn_t gpio_charger_irq(int irq, void *devid)
33{
34 struct power_supply *charger = devid;
35
36 power_supply_changed(charger);
37
38 return IRQ_HANDLED;
39}
40
41static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
42{
43 return power_supply_get_drvdata(psy);
44}
45
46static int gpio_charger_get_property(struct power_supply *psy,
47 enum power_supply_property psp, union power_supply_propval *val)
48{
49 struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
50
51 switch (psp) {
52 case POWER_SUPPLY_PROP_ONLINE:
53 val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
54 break;
55 case POWER_SUPPLY_PROP_STATUS:
56 if (gpiod_get_value_cansleep(gpio_charger->charge_status))
57 val->intval = POWER_SUPPLY_STATUS_CHARGING;
58 else
59 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
60 break;
61 default:
62 return -EINVAL;
63 }
64
65 return 0;
66}
67
68static enum power_supply_type gpio_charger_get_type(struct device *dev)
69{
70 const char *chargetype;
71
72 if (!device_property_read_string(dev, "charger-type", &chargetype)) {
73 if (!strcmp("unknown", chargetype))
74 return POWER_SUPPLY_TYPE_UNKNOWN;
75 if (!strcmp("battery", chargetype))
76 return POWER_SUPPLY_TYPE_BATTERY;
77 if (!strcmp("ups", chargetype))
78 return POWER_SUPPLY_TYPE_UPS;
79 if (!strcmp("mains", chargetype))
80 return POWER_SUPPLY_TYPE_MAINS;
81 if (!strcmp("usb-sdp", chargetype))
82 return POWER_SUPPLY_TYPE_USB;
83 if (!strcmp("usb-dcp", chargetype))
84 return POWER_SUPPLY_TYPE_USB;
85 if (!strcmp("usb-cdp", chargetype))
86 return POWER_SUPPLY_TYPE_USB;
87 if (!strcmp("usb-aca", chargetype))
88 return POWER_SUPPLY_TYPE_USB;
89 }
90 dev_warn(dev, "unknown charger type %s\n", chargetype);
91
92 return POWER_SUPPLY_TYPE_UNKNOWN;
93}
94
95static int gpio_charger_get_irq(struct device *dev, void *dev_id,
96 struct gpio_desc *gpio)
97{
98 int ret, irq = gpiod_to_irq(gpio);
99
100 if (irq > 0) {
101 ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq,
102 IRQF_TRIGGER_RISING |
103 IRQF_TRIGGER_FALLING,
104 dev_name(dev),
105 dev_id);
106 if (ret < 0) {
107 dev_warn(dev, "Failed to request irq: %d\n", ret);
108 irq = 0;
109 }
110 }
111
112 return irq;
113}
114
115static enum power_supply_property gpio_charger_properties[] = {
116 POWER_SUPPLY_PROP_ONLINE,
117 POWER_SUPPLY_PROP_STATUS /* Must always be last in the array. */
118};
119
120static int gpio_charger_probe(struct platform_device *pdev)
121{
122 struct device *dev = &pdev->dev;
123 const struct gpio_charger_platform_data *pdata = dev->platform_data;
124 struct power_supply_config psy_cfg = {};
125 struct gpio_charger *gpio_charger;
126 struct power_supply_desc *charger_desc;
127 struct gpio_desc *charge_status;
128 int charge_status_irq;
129 unsigned long flags;
130 int ret;
131
132 if (!pdata && !dev->of_node) {
133 dev_err(dev, "No platform data\n");
134 return -ENOENT;
135 }
136
137 gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL);
138 if (!gpio_charger)
139 return -ENOMEM;
140
141 /*
142 * This will fetch a GPIO descriptor from device tree, ACPI or
143 * boardfile descriptor tables. It's good to try this first.
144 */
145 gpio_charger->gpiod = devm_gpiod_get(dev, NULL, GPIOD_IN);
146
147 /*
148 * If this fails and we're not using device tree, try the
149 * legacy platform data method.
150 */
151 if (IS_ERR(gpio_charger->gpiod) && !dev->of_node) {
152 /* Non-DT: use legacy GPIO numbers */
153 if (!gpio_is_valid(pdata->gpio)) {
154 dev_err(dev, "Invalid gpio pin in pdata\n");
155 return -EINVAL;
156 }
157 flags = GPIOF_IN;
158 if (pdata->gpio_active_low)
159 flags |= GPIOF_ACTIVE_LOW;
160 ret = devm_gpio_request_one(dev, pdata->gpio, flags,
161 dev_name(dev));
162 if (ret) {
163 dev_err(dev, "Failed to request gpio pin: %d\n", ret);
164 return ret;
165 }
166 /* Then convert this to gpiod for now */
167 gpio_charger->gpiod = gpio_to_desc(pdata->gpio);
168 } else if (IS_ERR(gpio_charger->gpiod)) {
169 /* Just try again if this happens */
170 if (PTR_ERR(gpio_charger->gpiod) == -EPROBE_DEFER)
171 return -EPROBE_DEFER;
172 dev_err(dev, "error getting GPIO descriptor\n");
173 return PTR_ERR(gpio_charger->gpiod);
174 }
175
176 charge_status = devm_gpiod_get_optional(dev, "charge-status", GPIOD_IN);
177 gpio_charger->charge_status = charge_status;
178 if (IS_ERR(gpio_charger->charge_status))
179 return PTR_ERR(gpio_charger->charge_status);
180
181 charger_desc = &gpio_charger->charger_desc;
182 charger_desc->properties = gpio_charger_properties;
183 charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties);
184 /* Remove POWER_SUPPLY_PROP_STATUS from the supported properties. */
185 if (!gpio_charger->charge_status)
186 charger_desc->num_properties -= 1;
187 charger_desc->get_property = gpio_charger_get_property;
188
189 psy_cfg.of_node = dev->of_node;
190 psy_cfg.drv_data = gpio_charger;
191
192 if (pdata) {
193 charger_desc->name = pdata->name;
194 charger_desc->type = pdata->type;
195 psy_cfg.supplied_to = pdata->supplied_to;
196 psy_cfg.num_supplicants = pdata->num_supplicants;
197 } else {
198 charger_desc->name = dev->of_node->name;
199 charger_desc->type = gpio_charger_get_type(dev);
200 }
201
202 if (!charger_desc->name)
203 charger_desc->name = pdev->name;
204
205 gpio_charger->charger = devm_power_supply_register(dev, charger_desc,
206 &psy_cfg);
207 if (IS_ERR(gpio_charger->charger)) {
208 ret = PTR_ERR(gpio_charger->charger);
209 dev_err(dev, "Failed to register power supply: %d\n", ret);
210 return ret;
211 }
212
213 gpio_charger->irq = gpio_charger_get_irq(dev, gpio_charger->charger,
214 gpio_charger->gpiod);
215
216 charge_status_irq = gpio_charger_get_irq(dev, gpio_charger->charger,
217 gpio_charger->charge_status);
218 gpio_charger->charge_status_irq = charge_status_irq;
219
220 platform_set_drvdata(pdev, gpio_charger);
221
222 device_init_wakeup(dev, 1);
223
224 return 0;
225}
226
227#ifdef CONFIG_PM_SLEEP
228static int gpio_charger_suspend(struct device *dev)
229{
230 struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
231
232 if (device_may_wakeup(dev))
233 gpio_charger->wakeup_enabled =
234 !enable_irq_wake(gpio_charger->irq);
235
236 return 0;
237}
238
239static int gpio_charger_resume(struct device *dev)
240{
241 struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
242
243 if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
244 disable_irq_wake(gpio_charger->irq);
245 power_supply_changed(gpio_charger->charger);
246
247 return 0;
248}
249#endif
250
251static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
252 gpio_charger_suspend, gpio_charger_resume);
253
254static const struct of_device_id gpio_charger_match[] = {
255 { .compatible = "gpio-charger" },
256 { }
257};
258MODULE_DEVICE_TABLE(of, gpio_charger_match);
259
260static struct platform_driver gpio_charger_driver = {
261 .probe = gpio_charger_probe,
262 .driver = {
263 .name = "gpio-charger",
264 .pm = &gpio_charger_pm_ops,
265 .of_match_table = gpio_charger_match,
266 },
267};
268
269module_platform_driver(gpio_charger_driver);
270
271MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
272MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
273MODULE_LICENSE("GPL");
274MODULE_ALIAS("platform:gpio-charger");