1/* 2 * Battery measurement code for Zipit Z2 3 * 4 * Copyright (C) 2009 Peter Edwards <sweetlilmre@gmail.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 * 10 */ 11 12#include <linux/module.h> 13#include <linux/gpio.h> 14#include <linux/i2c.h> 15#include <linux/interrupt.h> 16#include <linux/irq.h> 17#include <linux/power_supply.h> 18#include <linux/slab.h> 19#include <linux/z2_battery.h> 20 21#define Z2_DEFAULT_NAME "Z2" 22 23struct z2_charger { 24 struct z2_battery_info *info; 25 int bat_status; 26 struct i2c_client *client; 27 struct power_supply *batt_ps; 28 struct power_supply_desc batt_ps_desc; 29 struct mutex work_lock; 30 struct work_struct bat_work; 31}; 32 33static unsigned long z2_read_bat(struct z2_charger *charger) 34{ 35 int data; 36 data = i2c_smbus_read_byte_data(charger->client, 37 charger->info->batt_I2C_reg); 38 if (data < 0) 39 return 0; 40 41 return data * charger->info->batt_mult / charger->info->batt_div; 42} 43 44static int z2_batt_get_property(struct power_supply *batt_ps, 45 enum power_supply_property psp, 46 union power_supply_propval *val) 47{ 48 struct z2_charger *charger = power_supply_get_drvdata(batt_ps); 49 struct z2_battery_info *info = charger->info; 50 51 switch (psp) { 52 case POWER_SUPPLY_PROP_STATUS: 53 val->intval = charger->bat_status; 54 break; 55 case POWER_SUPPLY_PROP_TECHNOLOGY: 56 val->intval = info->batt_tech; 57 break; 58 case POWER_SUPPLY_PROP_VOLTAGE_NOW: 59 if (info->batt_I2C_reg >= 0) 60 val->intval = z2_read_bat(charger); 61 else 62 return -EINVAL; 63 break; 64 case POWER_SUPPLY_PROP_VOLTAGE_MAX: 65 if (info->max_voltage >= 0) 66 val->intval = info->max_voltage; 67 else 68 return -EINVAL; 69 break; 70 case POWER_SUPPLY_PROP_VOLTAGE_MIN: 71 if (info->min_voltage >= 0) 72 val->intval = info->min_voltage; 73 else 74 return -EINVAL; 75 break; 76 case POWER_SUPPLY_PROP_PRESENT: 77 val->intval = 1; 78 break; 79 default: 80 return -EINVAL; 81 } 82 83 return 0; 84} 85 86static void z2_batt_ext_power_changed(struct power_supply *batt_ps) 87{ 88 struct z2_charger *charger = power_supply_get_drvdata(batt_ps); 89 90 schedule_work(&charger->bat_work); 91} 92 93static void z2_batt_update(struct z2_charger *charger) 94{ 95 int old_status = charger->bat_status; 96 struct z2_battery_info *info; 97 98 info = charger->info; 99 100 mutex_lock(&charger->work_lock); 101 102 charger->bat_status = (info->charge_gpio >= 0) ? 103 (gpio_get_value(info->charge_gpio) ? 104 POWER_SUPPLY_STATUS_CHARGING : 105 POWER_SUPPLY_STATUS_DISCHARGING) : 106 POWER_SUPPLY_STATUS_UNKNOWN; 107 108 if (old_status != charger->bat_status) { 109 pr_debug("%s: %i -> %i\n", charger->batt_ps->desc->name, 110 old_status, 111 charger->bat_status); 112 power_supply_changed(charger->batt_ps); 113 } 114 115 mutex_unlock(&charger->work_lock); 116} 117 118static void z2_batt_work(struct work_struct *work) 119{ 120 struct z2_charger *charger; 121 charger = container_of(work, struct z2_charger, bat_work); 122 z2_batt_update(charger); 123} 124 125static irqreturn_t z2_charge_switch_irq(int irq, void *devid) 126{ 127 struct z2_charger *charger = devid; 128 schedule_work(&charger->bat_work); 129 return IRQ_HANDLED; 130} 131 132static int z2_batt_ps_init(struct z2_charger *charger, int props) 133{ 134 int i = 0; 135 enum power_supply_property *prop; 136 struct z2_battery_info *info = charger->info; 137 138 if (info->charge_gpio >= 0) 139 props++; /* POWER_SUPPLY_PROP_STATUS */ 140 if (info->batt_tech >= 0) 141 props++; /* POWER_SUPPLY_PROP_TECHNOLOGY */ 142 if (info->batt_I2C_reg >= 0) 143 props++; /* POWER_SUPPLY_PROP_VOLTAGE_NOW */ 144 if (info->max_voltage >= 0) 145 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MAX */ 146 if (info->min_voltage >= 0) 147 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MIN */ 148 149 prop = kzalloc(props * sizeof(*prop), GFP_KERNEL); 150 if (!prop) 151 return -ENOMEM; 152 153 prop[i++] = POWER_SUPPLY_PROP_PRESENT; 154 if (info->charge_gpio >= 0) 155 prop[i++] = POWER_SUPPLY_PROP_STATUS; 156 if (info->batt_tech >= 0) 157 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY; 158 if (info->batt_I2C_reg >= 0) 159 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW; 160 if (info->max_voltage >= 0) 161 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX; 162 if (info->min_voltage >= 0) 163 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN; 164 165 if (!info->batt_name) { 166 dev_info(&charger->client->dev, 167 "Please consider setting proper battery " 168 "name in platform definition file, falling " 169 "back to name \" Z2_DEFAULT_NAME \"\n"); 170 charger->batt_ps_desc.name = Z2_DEFAULT_NAME; 171 } else 172 charger->batt_ps_desc.name = info->batt_name; 173 174 charger->batt_ps_desc.properties = prop; 175 charger->batt_ps_desc.num_properties = props; 176 charger->batt_ps_desc.type = POWER_SUPPLY_TYPE_BATTERY; 177 charger->batt_ps_desc.get_property = z2_batt_get_property; 178 charger->batt_ps_desc.external_power_changed = 179 z2_batt_ext_power_changed; 180 charger->batt_ps_desc.use_for_apm = 1; 181 182 return 0; 183} 184 185static int z2_batt_probe(struct i2c_client *client, 186 const struct i2c_device_id *id) 187{ 188 int ret = 0; 189 int props = 1; /* POWER_SUPPLY_PROP_PRESENT */ 190 struct z2_charger *charger; 191 struct z2_battery_info *info = client->dev.platform_data; 192 struct power_supply_config psy_cfg = {}; 193 194 if (info == NULL) { 195 dev_err(&client->dev, 196 "Please set platform device platform_data" 197 " to a valid z2_battery_info pointer!\n"); 198 return -EINVAL; 199 } 200 201 charger = kzalloc(sizeof(*charger), GFP_KERNEL); 202 if (charger == NULL) 203 return -ENOMEM; 204 205 charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN; 206 charger->info = info; 207 charger->client = client; 208 i2c_set_clientdata(client, charger); 209 psy_cfg.drv_data = charger; 210 211 mutex_init(&charger->work_lock); 212 213 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) { 214 ret = gpio_request(info->charge_gpio, "BATT CHRG"); 215 if (ret) 216 goto err; 217 218 ret = gpio_direction_input(info->charge_gpio); 219 if (ret) 220 goto err2; 221 222 irq_set_irq_type(gpio_to_irq(info->charge_gpio), 223 IRQ_TYPE_EDGE_BOTH); 224 ret = request_irq(gpio_to_irq(info->charge_gpio), 225 z2_charge_switch_irq, 0, 226 "AC Detect", charger); 227 if (ret) 228 goto err3; 229 } 230 231 ret = z2_batt_ps_init(charger, props); 232 if (ret) 233 goto err3; 234 235 INIT_WORK(&charger->bat_work, z2_batt_work); 236 237 charger->batt_ps = power_supply_register(&client->dev, 238 &charger->batt_ps_desc, 239 &psy_cfg); 240 if (IS_ERR(charger->batt_ps)) { 241 ret = PTR_ERR(charger->batt_ps); 242 goto err4; 243 } 244 245 schedule_work(&charger->bat_work); 246 247 return 0; 248 249err4: 250 kfree(charger->batt_ps_desc.properties); 251err3: 252 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) 253 free_irq(gpio_to_irq(info->charge_gpio), charger); 254err2: 255 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) 256 gpio_free(info->charge_gpio); 257err: 258 kfree(charger); 259 return ret; 260} 261 262static int z2_batt_remove(struct i2c_client *client) 263{ 264 struct z2_charger *charger = i2c_get_clientdata(client); 265 struct z2_battery_info *info = charger->info; 266 267 cancel_work_sync(&charger->bat_work); 268 power_supply_unregister(charger->batt_ps); 269 270 kfree(charger->batt_ps_desc.properties); 271 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) { 272 free_irq(gpio_to_irq(info->charge_gpio), charger); 273 gpio_free(info->charge_gpio); 274 } 275 276 kfree(charger); 277 278 return 0; 279} 280 281#ifdef CONFIG_PM 282static int z2_batt_suspend(struct device *dev) 283{ 284 struct i2c_client *client = to_i2c_client(dev); 285 struct z2_charger *charger = i2c_get_clientdata(client); 286 287 flush_work(&charger->bat_work); 288 return 0; 289} 290 291static int z2_batt_resume(struct device *dev) 292{ 293 struct i2c_client *client = to_i2c_client(dev); 294 struct z2_charger *charger = i2c_get_clientdata(client); 295 296 schedule_work(&charger->bat_work); 297 return 0; 298} 299 300static const struct dev_pm_ops z2_battery_pm_ops = { 301 .suspend = z2_batt_suspend, 302 .resume = z2_batt_resume, 303}; 304 305#define Z2_BATTERY_PM_OPS (&z2_battery_pm_ops) 306 307#else 308#define Z2_BATTERY_PM_OPS (NULL) 309#endif 310 311static const struct i2c_device_id z2_batt_id[] = { 312 { "aer915", 0 }, 313 { } 314}; 315MODULE_DEVICE_TABLE(i2c, z2_batt_id); 316 317static struct i2c_driver z2_batt_driver = { 318 .driver = { 319 .name = "z2-battery", 320 .owner = THIS_MODULE, 321 .pm = Z2_BATTERY_PM_OPS 322 }, 323 .probe = z2_batt_probe, 324 .remove = z2_batt_remove, 325 .id_table = z2_batt_id, 326}; 327module_i2c_driver(z2_batt_driver); 328 329MODULE_LICENSE("GPL"); 330MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>"); 331MODULE_DESCRIPTION("Zipit Z2 battery driver"); 332