1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Battery measurement code for Zipit Z2 4 * 5 * Copyright (C) 2009 Peter Edwards <sweetlilmre@gmail.com> 6 */ 7 8#include <linux/module.h> 9#include <linux/gpio.h> 10#include <linux/i2c.h> 11#include <linux/interrupt.h> 12#include <linux/irq.h> 13#include <linux/power_supply.h> 14#include <linux/slab.h> 15#include <linux/z2_battery.h> 16 17#define Z2_DEFAULT_NAME "Z2" 18 19struct z2_charger { 20 struct z2_battery_info *info; 21 int bat_status; 22 struct i2c_client *client; 23 struct power_supply *batt_ps; 24 struct power_supply_desc batt_ps_desc; 25 struct mutex work_lock; 26 struct work_struct bat_work; 27}; 28 29static unsigned long z2_read_bat(struct z2_charger *charger) 30{ 31 int data; 32 data = i2c_smbus_read_byte_data(charger->client, 33 charger->info->batt_I2C_reg); 34 if (data < 0) 35 return 0; 36 37 return data * charger->info->batt_mult / charger->info->batt_div; 38} 39 40static int z2_batt_get_property(struct power_supply *batt_ps, 41 enum power_supply_property psp, 42 union power_supply_propval *val) 43{ 44 struct z2_charger *charger = power_supply_get_drvdata(batt_ps); 45 struct z2_battery_info *info = charger->info; 46 47 switch (psp) { 48 case POWER_SUPPLY_PROP_STATUS: 49 val->intval = charger->bat_status; 50 break; 51 case POWER_SUPPLY_PROP_TECHNOLOGY: 52 val->intval = info->batt_tech; 53 break; 54 case POWER_SUPPLY_PROP_VOLTAGE_NOW: 55 if (info->batt_I2C_reg >= 0) 56 val->intval = z2_read_bat(charger); 57 else 58 return -EINVAL; 59 break; 60 case POWER_SUPPLY_PROP_VOLTAGE_MAX: 61 if (info->max_voltage >= 0) 62 val->intval = info->max_voltage; 63 else 64 return -EINVAL; 65 break; 66 case POWER_SUPPLY_PROP_VOLTAGE_MIN: 67 if (info->min_voltage >= 0) 68 val->intval = info->min_voltage; 69 else 70 return -EINVAL; 71 break; 72 case POWER_SUPPLY_PROP_PRESENT: 73 val->intval = 1; 74 break; 75 default: 76 return -EINVAL; 77 } 78 79 return 0; 80} 81 82static void z2_batt_ext_power_changed(struct power_supply *batt_ps) 83{ 84 struct z2_charger *charger = power_supply_get_drvdata(batt_ps); 85 86 schedule_work(&charger->bat_work); 87} 88 89static void z2_batt_update(struct z2_charger *charger) 90{ 91 int old_status = charger->bat_status; 92 struct z2_battery_info *info; 93 94 info = charger->info; 95 96 mutex_lock(&charger->work_lock); 97 98 charger->bat_status = (info->charge_gpio >= 0) ? 99 (gpio_get_value(info->charge_gpio) ? 100 POWER_SUPPLY_STATUS_CHARGING : 101 POWER_SUPPLY_STATUS_DISCHARGING) : 102 POWER_SUPPLY_STATUS_UNKNOWN; 103 104 if (old_status != charger->bat_status) { 105 pr_debug("%s: %i -> %i\n", charger->batt_ps->desc->name, 106 old_status, 107 charger->bat_status); 108 power_supply_changed(charger->batt_ps); 109 } 110 111 mutex_unlock(&charger->work_lock); 112} 113 114static void z2_batt_work(struct work_struct *work) 115{ 116 struct z2_charger *charger; 117 charger = container_of(work, struct z2_charger, bat_work); 118 z2_batt_update(charger); 119} 120 121static irqreturn_t z2_charge_switch_irq(int irq, void *devid) 122{ 123 struct z2_charger *charger = devid; 124 schedule_work(&charger->bat_work); 125 return IRQ_HANDLED; 126} 127 128static int z2_batt_ps_init(struct z2_charger *charger, int props) 129{ 130 int i = 0; 131 enum power_supply_property *prop; 132 struct z2_battery_info *info = charger->info; 133 134 if (info->charge_gpio >= 0) 135 props++; /* POWER_SUPPLY_PROP_STATUS */ 136 if (info->batt_tech >= 0) 137 props++; /* POWER_SUPPLY_PROP_TECHNOLOGY */ 138 if (info->batt_I2C_reg >= 0) 139 props++; /* POWER_SUPPLY_PROP_VOLTAGE_NOW */ 140 if (info->max_voltage >= 0) 141 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MAX */ 142 if (info->min_voltage >= 0) 143 props++; /* POWER_SUPPLY_PROP_VOLTAGE_MIN */ 144 145 prop = kcalloc(props, sizeof(*prop), GFP_KERNEL); 146 if (!prop) 147 return -ENOMEM; 148 149 prop[i++] = POWER_SUPPLY_PROP_PRESENT; 150 if (info->charge_gpio >= 0) 151 prop[i++] = POWER_SUPPLY_PROP_STATUS; 152 if (info->batt_tech >= 0) 153 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY; 154 if (info->batt_I2C_reg >= 0) 155 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW; 156 if (info->max_voltage >= 0) 157 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX; 158 if (info->min_voltage >= 0) 159 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN; 160 161 if (!info->batt_name) { 162 dev_info(&charger->client->dev, 163 "Please consider setting proper battery " 164 "name in platform definition file, falling " 165 "back to name \" Z2_DEFAULT_NAME \"\n"); 166 charger->batt_ps_desc.name = Z2_DEFAULT_NAME; 167 } else 168 charger->batt_ps_desc.name = info->batt_name; 169 170 charger->batt_ps_desc.properties = prop; 171 charger->batt_ps_desc.num_properties = props; 172 charger->batt_ps_desc.type = POWER_SUPPLY_TYPE_BATTERY; 173 charger->batt_ps_desc.get_property = z2_batt_get_property; 174 charger->batt_ps_desc.external_power_changed = 175 z2_batt_ext_power_changed; 176 charger->batt_ps_desc.use_for_apm = 1; 177 178 return 0; 179} 180 181static int z2_batt_probe(struct i2c_client *client, 182 const struct i2c_device_id *id) 183{ 184 int ret = 0; 185 int props = 1; /* POWER_SUPPLY_PROP_PRESENT */ 186 struct z2_charger *charger; 187 struct z2_battery_info *info = client->dev.platform_data; 188 struct power_supply_config psy_cfg = {}; 189 190 if (info == NULL) { 191 dev_err(&client->dev, 192 "Please set platform device platform_data" 193 " to a valid z2_battery_info pointer!\n"); 194 return -EINVAL; 195 } 196 197 charger = kzalloc(sizeof(*charger), GFP_KERNEL); 198 if (charger == NULL) 199 return -ENOMEM; 200 201 charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN; 202 charger->info = info; 203 charger->client = client; 204 i2c_set_clientdata(client, charger); 205 psy_cfg.drv_data = charger; 206 207 mutex_init(&charger->work_lock); 208 209 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) { 210 ret = gpio_request(info->charge_gpio, "BATT CHRG"); 211 if (ret) 212 goto err; 213 214 ret = gpio_direction_input(info->charge_gpio); 215 if (ret) 216 goto err2; 217 218 irq_set_irq_type(gpio_to_irq(info->charge_gpio), 219 IRQ_TYPE_EDGE_BOTH); 220 ret = request_irq(gpio_to_irq(info->charge_gpio), 221 z2_charge_switch_irq, 0, 222 "AC Detect", charger); 223 if (ret) 224 goto err3; 225 } 226 227 ret = z2_batt_ps_init(charger, props); 228 if (ret) 229 goto err3; 230 231 INIT_WORK(&charger->bat_work, z2_batt_work); 232 233 charger->batt_ps = power_supply_register(&client->dev, 234 &charger->batt_ps_desc, 235 &psy_cfg); 236 if (IS_ERR(charger->batt_ps)) { 237 ret = PTR_ERR(charger->batt_ps); 238 goto err4; 239 } 240 241 schedule_work(&charger->bat_work); 242 243 return 0; 244 245err4: 246 kfree(charger->batt_ps_desc.properties); 247err3: 248 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) 249 free_irq(gpio_to_irq(info->charge_gpio), charger); 250err2: 251 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) 252 gpio_free(info->charge_gpio); 253err: 254 kfree(charger); 255 return ret; 256} 257 258static int z2_batt_remove(struct i2c_client *client) 259{ 260 struct z2_charger *charger = i2c_get_clientdata(client); 261 struct z2_battery_info *info = charger->info; 262 263 cancel_work_sync(&charger->bat_work); 264 power_supply_unregister(charger->batt_ps); 265 266 kfree(charger->batt_ps_desc.properties); 267 if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) { 268 free_irq(gpio_to_irq(info->charge_gpio), charger); 269 gpio_free(info->charge_gpio); 270 } 271 272 kfree(charger); 273 274 return 0; 275} 276 277#ifdef CONFIG_PM 278static int z2_batt_suspend(struct device *dev) 279{ 280 struct i2c_client *client = to_i2c_client(dev); 281 struct z2_charger *charger = i2c_get_clientdata(client); 282 283 flush_work(&charger->bat_work); 284 return 0; 285} 286 287static int z2_batt_resume(struct device *dev) 288{ 289 struct i2c_client *client = to_i2c_client(dev); 290 struct z2_charger *charger = i2c_get_clientdata(client); 291 292 schedule_work(&charger->bat_work); 293 return 0; 294} 295 296static const struct dev_pm_ops z2_battery_pm_ops = { 297 .suspend = z2_batt_suspend, 298 .resume = z2_batt_resume, 299}; 300 301#define Z2_BATTERY_PM_OPS (&z2_battery_pm_ops) 302 303#else 304#define Z2_BATTERY_PM_OPS (NULL) 305#endif 306 307static const struct i2c_device_id z2_batt_id[] = { 308 { "aer915", 0 }, 309 { } 310}; 311MODULE_DEVICE_TABLE(i2c, z2_batt_id); 312 313static struct i2c_driver z2_batt_driver = { 314 .driver = { 315 .name = "z2-battery", 316 .pm = Z2_BATTERY_PM_OPS 317 }, 318 .probe = z2_batt_probe, 319 .remove = z2_batt_remove, 320 .id_table = z2_batt_id, 321}; 322module_i2c_driver(z2_batt_driver); 323 324MODULE_LICENSE("GPL"); 325MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>"); 326MODULE_DESCRIPTION("Zipit Z2 battery driver"); 327