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> /* For legacy platform data */ 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/gpio/consumer.h> 27 28 #include <linux/power/gpio-charger.h> 29 30 struct gpio_charger { 31 unsigned int irq; 32 unsigned int charge_status_irq; 33 bool wakeup_enabled; 34 35 struct power_supply *charger; 36 struct power_supply_desc charger_desc; 37 struct gpio_desc *gpiod; 38 struct gpio_desc *charge_status; 39 }; 40 41 static irqreturn_t gpio_charger_irq(int irq, void *devid) 42 { 43 struct power_supply *charger = devid; 44 45 power_supply_changed(charger); 46 47 return IRQ_HANDLED; 48 } 49 50 static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy) 51 { 52 return power_supply_get_drvdata(psy); 53 } 54 55 static int gpio_charger_get_property(struct power_supply *psy, 56 enum power_supply_property psp, union power_supply_propval *val) 57 { 58 struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy); 59 60 switch (psp) { 61 case POWER_SUPPLY_PROP_ONLINE: 62 val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod); 63 break; 64 case POWER_SUPPLY_PROP_STATUS: 65 if (gpiod_get_value_cansleep(gpio_charger->charge_status)) 66 val->intval = POWER_SUPPLY_STATUS_CHARGING; 67 else 68 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; 69 break; 70 default: 71 return -EINVAL; 72 } 73 74 return 0; 75 } 76 77 static enum power_supply_type gpio_charger_get_type(struct device *dev) 78 { 79 const char *chargetype; 80 81 if (!device_property_read_string(dev, "charger-type", &chargetype)) { 82 if (!strcmp("unknown", chargetype)) 83 return POWER_SUPPLY_TYPE_UNKNOWN; 84 if (!strcmp("battery", chargetype)) 85 return POWER_SUPPLY_TYPE_BATTERY; 86 if (!strcmp("ups", chargetype)) 87 return POWER_SUPPLY_TYPE_UPS; 88 if (!strcmp("mains", chargetype)) 89 return POWER_SUPPLY_TYPE_MAINS; 90 if (!strcmp("usb-sdp", chargetype)) 91 return POWER_SUPPLY_TYPE_USB; 92 if (!strcmp("usb-dcp", chargetype)) 93 return POWER_SUPPLY_TYPE_USB; 94 if (!strcmp("usb-cdp", chargetype)) 95 return POWER_SUPPLY_TYPE_USB; 96 if (!strcmp("usb-aca", chargetype)) 97 return POWER_SUPPLY_TYPE_USB; 98 } 99 dev_warn(dev, "unknown charger type %s\n", chargetype); 100 101 return POWER_SUPPLY_TYPE_UNKNOWN; 102 } 103 104 static int gpio_charger_get_irq(struct device *dev, void *dev_id, 105 struct gpio_desc *gpio) 106 { 107 int ret, irq = gpiod_to_irq(gpio); 108 109 if (irq > 0) { 110 ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq, 111 IRQF_TRIGGER_RISING | 112 IRQF_TRIGGER_FALLING, 113 dev_name(dev), 114 dev_id); 115 if (ret < 0) { 116 dev_warn(dev, "Failed to request irq: %d\n", ret); 117 irq = 0; 118 } 119 } 120 121 return irq; 122 } 123 124 static enum power_supply_property gpio_charger_properties[] = { 125 POWER_SUPPLY_PROP_ONLINE, 126 POWER_SUPPLY_PROP_STATUS /* Must always be last in the array. */ 127 }; 128 129 static int gpio_charger_probe(struct platform_device *pdev) 130 { 131 struct device *dev = &pdev->dev; 132 const struct gpio_charger_platform_data *pdata = dev->platform_data; 133 struct power_supply_config psy_cfg = {}; 134 struct gpio_charger *gpio_charger; 135 struct power_supply_desc *charger_desc; 136 struct gpio_desc *charge_status; 137 int charge_status_irq; 138 unsigned long flags; 139 int ret; 140 141 if (!pdata && !dev->of_node) { 142 dev_err(dev, "No platform data\n"); 143 return -ENOENT; 144 } 145 146 gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL); 147 if (!gpio_charger) 148 return -ENOMEM; 149 150 /* 151 * This will fetch a GPIO descriptor from device tree, ACPI or 152 * boardfile descriptor tables. It's good to try this first. 153 */ 154 gpio_charger->gpiod = devm_gpiod_get(dev, NULL, GPIOD_IN); 155 156 /* 157 * If this fails and we're not using device tree, try the 158 * legacy platform data method. 159 */ 160 if (IS_ERR(gpio_charger->gpiod) && !dev->of_node) { 161 /* Non-DT: use legacy GPIO numbers */ 162 if (!gpio_is_valid(pdata->gpio)) { 163 dev_err(dev, "Invalid gpio pin in pdata\n"); 164 return -EINVAL; 165 } 166 flags = GPIOF_IN; 167 if (pdata->gpio_active_low) 168 flags |= GPIOF_ACTIVE_LOW; 169 ret = devm_gpio_request_one(dev, pdata->gpio, flags, 170 dev_name(dev)); 171 if (ret) { 172 dev_err(dev, "Failed to request gpio pin: %d\n", ret); 173 return ret; 174 } 175 /* Then convert this to gpiod for now */ 176 gpio_charger->gpiod = gpio_to_desc(pdata->gpio); 177 } else if (IS_ERR(gpio_charger->gpiod)) { 178 /* Just try again if this happens */ 179 if (PTR_ERR(gpio_charger->gpiod) == -EPROBE_DEFER) 180 return -EPROBE_DEFER; 181 dev_err(dev, "error getting GPIO descriptor\n"); 182 return PTR_ERR(gpio_charger->gpiod); 183 } 184 185 charge_status = devm_gpiod_get_optional(dev, "charge-status", GPIOD_IN); 186 gpio_charger->charge_status = charge_status; 187 if (IS_ERR(gpio_charger->charge_status)) 188 return PTR_ERR(gpio_charger->charge_status); 189 190 charger_desc = &gpio_charger->charger_desc; 191 charger_desc->properties = gpio_charger_properties; 192 charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties); 193 /* Remove POWER_SUPPLY_PROP_STATUS from the supported properties. */ 194 if (!gpio_charger->charge_status) 195 charger_desc->num_properties -= 1; 196 charger_desc->get_property = gpio_charger_get_property; 197 198 psy_cfg.of_node = dev->of_node; 199 psy_cfg.drv_data = gpio_charger; 200 201 if (pdata) { 202 charger_desc->name = pdata->name; 203 charger_desc->type = pdata->type; 204 psy_cfg.supplied_to = pdata->supplied_to; 205 psy_cfg.num_supplicants = pdata->num_supplicants; 206 } else { 207 charger_desc->name = dev->of_node->name; 208 charger_desc->type = gpio_charger_get_type(dev); 209 } 210 211 if (!charger_desc->name) 212 charger_desc->name = pdev->name; 213 214 gpio_charger->charger = devm_power_supply_register(dev, charger_desc, 215 &psy_cfg); 216 if (IS_ERR(gpio_charger->charger)) { 217 ret = PTR_ERR(gpio_charger->charger); 218 dev_err(dev, "Failed to register power supply: %d\n", ret); 219 return ret; 220 } 221 222 gpio_charger->irq = gpio_charger_get_irq(dev, gpio_charger->charger, 223 gpio_charger->gpiod); 224 225 charge_status_irq = gpio_charger_get_irq(dev, gpio_charger->charger, 226 gpio_charger->charge_status); 227 gpio_charger->charge_status_irq = charge_status_irq; 228 229 platform_set_drvdata(pdev, gpio_charger); 230 231 device_init_wakeup(dev, 1); 232 233 return 0; 234 } 235 236 #ifdef CONFIG_PM_SLEEP 237 static int gpio_charger_suspend(struct device *dev) 238 { 239 struct gpio_charger *gpio_charger = dev_get_drvdata(dev); 240 241 if (device_may_wakeup(dev)) 242 gpio_charger->wakeup_enabled = 243 !enable_irq_wake(gpio_charger->irq); 244 245 return 0; 246 } 247 248 static int gpio_charger_resume(struct device *dev) 249 { 250 struct gpio_charger *gpio_charger = dev_get_drvdata(dev); 251 252 if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled) 253 disable_irq_wake(gpio_charger->irq); 254 power_supply_changed(gpio_charger->charger); 255 256 return 0; 257 } 258 #endif 259 260 static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops, 261 gpio_charger_suspend, gpio_charger_resume); 262 263 static const struct of_device_id gpio_charger_match[] = { 264 { .compatible = "gpio-charger" }, 265 { } 266 }; 267 MODULE_DEVICE_TABLE(of, gpio_charger_match); 268 269 static struct platform_driver gpio_charger_driver = { 270 .probe = gpio_charger_probe, 271 .driver = { 272 .name = "gpio-charger", 273 .pm = &gpio_charger_pm_ops, 274 .of_match_table = gpio_charger_match, 275 }, 276 }; 277 278 module_platform_driver(gpio_charger_driver); 279 280 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 281 MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO"); 282 MODULE_LICENSE("GPL"); 283 MODULE_ALIAS("platform:gpio-charger"); 284