| 1 | /* |
| 2 | * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> |
| 3 | * Driver for chargers indicating their 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/kernel.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/init.h> |
| 19 | #include <linux/types.h> |
| 20 | #include <linux/device.h> |
| 21 | #include <linux/platform_device.h> |
| 22 | #include <linux/power_supply.h> |
| 23 | #include <linux/interrupt.h> |
| 24 | #include <linux/gpio.h> |
| 25 | |
| 26 | #include <linux/power/gpio-charger.h> |
| 27 | |
| 28 | struct gpio_charger { |
| 29 | const struct gpio_charger_platform_data *pdata; |
| 30 | |
| 31 | int irq; |
| 32 | |
| 33 | struct power_supply charger; |
| 34 | }; |
| 35 | |
| 36 | static irqreturn_t gpio_charger_irq(int irq, void *devid) |
| 37 | { |
| 38 | struct power_supply *charger = devid; |
| 39 | power_supply_changed(charger); |
| 40 | |
| 41 | return IRQ_HANDLED; |
| 42 | } |
| 43 | |
| 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 | |
| 49 | static int gpio_charger_get_property(struct power_supply *psy, |
| 50 | enum power_supply_property psp, |
| 51 | 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(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 | |
| 72 | static int __devinit 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 | |
| 79 | if (!pdata) { |
| 80 | dev_err(&pdev->dev, "No platform data"); |
| 81 | return -EINVAL; |
| 82 | } |
| 83 | |
| 84 | gpio_charger = kzalloc(sizeof(*gpio_charger), GFP_KERNEL); |
| 85 | |
| 86 | charger = &gpio_charger->charger; |
| 87 | |
| 88 | charger->name = pdata->name; |
| 89 | charger->type = pdata->type; |
| 90 | charger->properties = gpio_charger_properties; |
| 91 | charger->num_properties = ARRAY_SIZE(gpio_charger_properties); |
| 92 | charger->get_property = gpio_charger_get_property; |
| 93 | charger->supplied_to = pdata->batteries; |
| 94 | charger->num_supplicants = pdata->num_batteries; |
| 95 | |
| 96 | if (gpio_is_valid(pdata->gpio)) { |
| 97 | ret = gpio_request(pdata->gpio, dev_name(&pdev->dev)); |
| 98 | if (ret) { |
| 99 | dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret); |
| 100 | goto err; |
| 101 | } |
| 102 | ret = gpio_direction_input(pdata->gpio); |
| 103 | if (ret) { |
| 104 | dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret); |
| 105 | goto err_gpio_free; |
| 106 | } |
| 107 | |
| 108 | gpio_charger->irq = gpio_to_irq(pdata->gpio); |
| 109 | if (gpio_charger->irq >= 0) { |
| 110 | ret = request_irq(gpio_charger->irq, gpio_charger_irq, |
| 111 | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, |
| 112 | dev_name(&pdev->dev), charger); |
| 113 | if (ret) { |
| 114 | dev_warn(&pdev->dev, "Failed to request online gpio irq: %d\n", ret); |
| 115 | gpio_charger->irq = -1; |
| 116 | } |
| 117 | } |
| 118 | } |
| 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", ret); |
| 123 | goto err_gpio_free; |
| 124 | } |
| 125 | |
| 126 | gpio_charger->pdata = pdata; |
| 127 | platform_set_drvdata(pdev, gpio_charger); |
| 128 | |
| 129 | return 0; |
| 130 | |
| 131 | err_gpio_free: |
| 132 | if (gpio_is_valid(pdata->gpio)) { |
| 133 | if (gpio_charger->irq >= 0) |
| 134 | free_irq(gpio_charger->irq, charger); |
| 135 | gpio_free(pdata->gpio); |
| 136 | } |
| 137 | err: |
| 138 | return ret; |
| 139 | } |
| 140 | |
| 141 | static int __devexit gpio_charger_remove(struct platform_device *pdev) |
| 142 | { |
| 143 | struct gpio_charger *gpio_charger = platform_get_drvdata(pdev); |
| 144 | const struct gpio_charger_platform_data *pdata = gpio_charger->pdata; |
| 145 | |
| 146 | power_supply_unregister(&gpio_charger->charger); |
| 147 | |
| 148 | if (gpio_is_valid(pdata->gpio)) { |
| 149 | if (gpio_charger->irq >= 0) |
| 150 | free_irq(gpio_charger->irq, &gpio_charger->charger); |
| 151 | gpio_free(pdata->gpio); |
| 152 | } |
| 153 | |
| 154 | platform_set_drvdata(pdev, NULL); |
| 155 | kfree(gpio_charger); |
| 156 | |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | static struct platform_driver gpio_charger_driver = { |
| 161 | .probe = gpio_charger_probe, |
| 162 | .remove = __devexit_p(gpio_charger_remove), |
| 163 | .driver = { |
| 164 | .name = "gpio-charger", |
| 165 | .owner = THIS_MODULE, |
| 166 | }, |
| 167 | }; |
| 168 | |
| 169 | static int __init gpio_charger_init(void) |
| 170 | { |
| 171 | return platform_driver_register(&gpio_charger_driver); |
| 172 | } |
| 173 | module_init(gpio_charger_init); |
| 174 | |
| 175 | static void gpio_charger_exit(void) |
| 176 | { |
| 177 | platform_driver_unregister(&gpio_charger_driver); |
| 178 | } |
| 179 | module_exit(gpio_charger_exit); |
| 180 | |
| 181 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); |
| 182 | MODULE_DESCRIPTION("Driver for chargers indicating their status through a gpio"); |
| 183 | MODULE_LICENSE("GPL"); |
| 184 | MODULE_ALIAS("platform:gpio-charger"); |
| 185 | |
