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 21 struct 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 32 static 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 41 static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy) 42 { 43 return power_supply_get_drvdata(psy); 44 } 45 46 static 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 68 static 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 95 static 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 } 114 115 static 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 }; 119 120 static 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 228 static 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 } 238 239 static 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 250 251 static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops, 252 gpio_charger_suspend, gpio_charger_resume); 253 254 static const struct of_device_id gpio_charger_match[] = { 255 { .compatible = "gpio-charger" }, 256 { } 257 }; 258 MODULE_DEVICE_TABLE(of, gpio_charger_match); 259 260 static 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 }; 268 269 module_platform_driver(gpio_charger_driver); 270 271 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 272 MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO"); 273 MODULE_LICENSE("GPL"); 274 MODULE_ALIAS("platform:gpio-charger"); 275