power/supply/z2_battery.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Battery measurement code for Zipit Z2
0004  *
0005  * Copyright (C) 2009 Peter Edwards <sweetlilmre@gmail.com>
0006  */
0007
0008 #include <linux/module.h>
0009 #include <linux/gpio/consumer.h>
0010 #include <linux/i2c.h>
0011 #include <linux/interrupt.h>
0012 #include <linux/irq.h>
0013 #include <linux/power_supply.h>
0014 #include <linux/slab.h>
0015 #include <linux/z2_battery.h>
0016
0017 #define Z2_DEFAULT_NAME "Z2"
0018
0019 struct z2_charger {
0020     struct z2_battery_info      *info;
0021     struct gpio_desc        *charge_gpiod;
0022     int             bat_status;
0023     struct i2c_client       *client;
0024     struct power_supply     *batt_ps;
0025     struct power_supply_desc    batt_ps_desc;
0026     struct mutex            work_lock;
0027     struct work_struct      bat_work;
0028 };
0029
0030 static unsigned long z2_read_bat(struct z2_charger *charger)
0031 {
0032     int data;
0033     data = i2c_smbus_read_byte_data(charger->client,
0034                     charger->info->batt_I2C_reg);
0035     if (data < 0)
0036         return 0;
0037
0038     return data * charger->info->batt_mult / charger->info->batt_div;
0039 }
0040
0041 static int z2_batt_get_property(struct power_supply *batt_ps,
0042                 enum power_supply_property psp,
0043                 union power_supply_propval *val)
0044 {
0045     struct z2_charger *charger = power_supply_get_drvdata(batt_ps);
0046     struct z2_battery_info *info = charger->info;
0047
0048     switch (psp) {
0049     case POWER_SUPPLY_PROP_STATUS:
0050         val->intval = charger->bat_status;
0051         break;
0052     case POWER_SUPPLY_PROP_TECHNOLOGY:
0053         val->intval = info->batt_tech;
0054         break;
0055     case POWER_SUPPLY_PROP_VOLTAGE_NOW:
0056         if (info->batt_I2C_reg >= 0)
0057             val->intval = z2_read_bat(charger);
0058         else
0059             return -EINVAL;
0060         break;
0061     case POWER_SUPPLY_PROP_VOLTAGE_MAX:
0062         if (info->max_voltage >= 0)
0063             val->intval = info->max_voltage;
0064         else
0065             return -EINVAL;
0066         break;
0067     case POWER_SUPPLY_PROP_VOLTAGE_MIN:
0068         if (info->min_voltage >= 0)
0069             val->intval = info->min_voltage;
0070         else
0071             return -EINVAL;
0072         break;
0073     case POWER_SUPPLY_PROP_PRESENT:
0074         val->intval = 1;
0075         break;
0076     default:
0077         return -EINVAL;
0078     }
0079
0080     return 0;
0081 }
0082
0083 static void z2_batt_ext_power_changed(struct power_supply *batt_ps)
0084 {
0085     struct z2_charger *charger = power_supply_get_drvdata(batt_ps);
0086
0087     schedule_work(&charger->bat_work);
0088 }
0089
0090 static void z2_batt_update(struct z2_charger *charger)
0091 {
0092     int old_status = charger->bat_status;
0093
0094     mutex_lock(&charger->work_lock);
0095
0096     charger->bat_status = charger->charge_gpiod ?
0097         (gpiod_get_value(charger->charge_gpiod) ?
0098         POWER_SUPPLY_STATUS_CHARGING :
0099         POWER_SUPPLY_STATUS_DISCHARGING) :
0100         POWER_SUPPLY_STATUS_UNKNOWN;
0101
0102     if (old_status != charger->bat_status) {
0103         pr_debug("%s: %i -> %i\n", charger->batt_ps->desc->name,
0104                 old_status,
0105                 charger->bat_status);
0106         power_supply_changed(charger->batt_ps);
0107     }
0108
0109     mutex_unlock(&charger->work_lock);
0110 }
0111
0112 static void z2_batt_work(struct work_struct *work)
0113 {
0114     struct z2_charger *charger;
0115     charger = container_of(work, struct z2_charger, bat_work);
0116     z2_batt_update(charger);
0117 }
0118
0119 static irqreturn_t z2_charge_switch_irq(int irq, void *devid)
0120 {
0121     struct z2_charger *charger = devid;
0122     schedule_work(&charger->bat_work);
0123     return IRQ_HANDLED;
0124 }
0125
0126 static int z2_batt_ps_init(struct z2_charger *charger, int props)
0127 {
0128     int i = 0;
0129     enum power_supply_property *prop;
0130     struct z2_battery_info *info = charger->info;
0131
0132     if (charger->charge_gpiod)
0133         props++;    /* POWER_SUPPLY_PROP_STATUS */
0134     if (info->batt_tech >= 0)
0135         props++;    /* POWER_SUPPLY_PROP_TECHNOLOGY */
0136     if (info->batt_I2C_reg >= 0)
0137         props++;    /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
0138     if (info->max_voltage >= 0)
0139         props++;    /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
0140     if (info->min_voltage >= 0)
0141         props++;    /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
0142
0143     prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
0144     if (!prop)
0145         return -ENOMEM;
0146
0147     prop[i++] = POWER_SUPPLY_PROP_PRESENT;
0148     if (charger->charge_gpiod)
0149         prop[i++] = POWER_SUPPLY_PROP_STATUS;
0150     if (info->batt_tech >= 0)
0151         prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
0152     if (info->batt_I2C_reg >= 0)
0153         prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
0154     if (info->max_voltage >= 0)
0155         prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
0156     if (info->min_voltage >= 0)
0157         prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
0158
0159     if (!info->batt_name) {
0160         dev_info(&charger->client->dev,
0161                 "Please consider setting proper battery "
0162                 "name in platform definition file, falling "
0163                 "back to name \" Z2_DEFAULT_NAME \"\n");
0164         charger->batt_ps_desc.name = Z2_DEFAULT_NAME;
0165     } else
0166         charger->batt_ps_desc.name = info->batt_name;
0167
0168     charger->batt_ps_desc.properties    = prop;
0169     charger->batt_ps_desc.num_properties    = props;
0170     charger->batt_ps_desc.type      = POWER_SUPPLY_TYPE_BATTERY;
0171     charger->batt_ps_desc.get_property  = z2_batt_get_property;
0172     charger->batt_ps_desc.external_power_changed =
0173                         z2_batt_ext_power_changed;
0174     charger->batt_ps_desc.use_for_apm   = 1;
0175
0176     return 0;
0177 }
0178
0179 static int z2_batt_probe(struct i2c_client *client,
0180                 const struct i2c_device_id *id)
0181 {
0182     int ret = 0;
0183     int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
0184     struct z2_charger *charger;
0185     struct z2_battery_info *info = client->dev.platform_data;
0186     struct power_supply_config psy_cfg = {};
0187
0188     if (info == NULL) {
0189         dev_err(&client->dev,
0190             "Please set platform device platform_data"
0191             " to a valid z2_battery_info pointer!\n");
0192         return -EINVAL;
0193     }
0194
0195     charger = kzalloc(sizeof(*charger), GFP_KERNEL);
0196     if (charger == NULL)
0197         return -ENOMEM;
0198
0199     charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
0200     charger->info = info;
0201     charger->client = client;
0202     i2c_set_clientdata(client, charger);
0203     psy_cfg.drv_data = charger;
0204
0205     mutex_init(&charger->work_lock);
0206
0207     charger->charge_gpiod = devm_gpiod_get_optional(&client->dev,
0208                             NULL, GPIOD_IN);
0209     if (IS_ERR(charger->charge_gpiod))
0210         return dev_err_probe(&client->dev,
0211                      PTR_ERR(charger->charge_gpiod),
0212                      "failed to get charge GPIO\n");
0213
0214     if (charger->charge_gpiod) {
0215         gpiod_set_consumer_name(charger->charge_gpiod, "BATT CHRG");
0216
0217         irq_set_irq_type(gpiod_to_irq(charger->charge_gpiod),
0218                  IRQ_TYPE_EDGE_BOTH);
0219         ret = request_irq(gpiod_to_irq(charger->charge_gpiod),
0220                 z2_charge_switch_irq, 0,
0221                 "AC Detect", charger);
0222         if (ret)
0223             goto err;
0224     }
0225
0226     ret = z2_batt_ps_init(charger, props);
0227     if (ret)
0228         goto err3;
0229
0230     INIT_WORK(&charger->bat_work, z2_batt_work);
0231
0232     charger->batt_ps = power_supply_register(&client->dev,
0233                          &charger->batt_ps_desc,
0234                          &psy_cfg);
0235     if (IS_ERR(charger->batt_ps)) {
0236         ret = PTR_ERR(charger->batt_ps);
0237         goto err4;
0238     }
0239
0240     schedule_work(&charger->bat_work);
0241
0242     return 0;
0243
0244 err4:
0245     kfree(charger->batt_ps_desc.properties);
0246 err3:
0247     if (charger->charge_gpiod)
0248         free_irq(gpiod_to_irq(charger->charge_gpiod), charger);
0249 err:
0250     kfree(charger);
0251     return ret;
0252 }
0253
0254 static int z2_batt_remove(struct i2c_client *client)
0255 {
0256     struct z2_charger *charger = i2c_get_clientdata(client);
0257
0258     cancel_work_sync(&charger->bat_work);
0259     power_supply_unregister(charger->batt_ps);
0260
0261     kfree(charger->batt_ps_desc.properties);
0262     if (charger->charge_gpiod)
0263         free_irq(gpiod_to_irq(charger->charge_gpiod), charger);
0264
0265     kfree(charger);
0266
0267     return 0;
0268 }
0269
0270 #ifdef CONFIG_PM
0271 static int z2_batt_suspend(struct device *dev)
0272 {
0273     struct i2c_client *client = to_i2c_client(dev);
0274     struct z2_charger *charger = i2c_get_clientdata(client);
0275
0276     flush_work(&charger->bat_work);
0277     return 0;
0278 }
0279
0280 static int z2_batt_resume(struct device *dev)
0281 {
0282     struct i2c_client *client = to_i2c_client(dev);
0283     struct z2_charger *charger = i2c_get_clientdata(client);
0284
0285     schedule_work(&charger->bat_work);
0286     return 0;
0287 }
0288
0289 static const struct dev_pm_ops z2_battery_pm_ops = {
0290     .suspend    = z2_batt_suspend,
0291     .resume     = z2_batt_resume,
0292 };
0293
0294 #define Z2_BATTERY_PM_OPS   (&z2_battery_pm_ops)
0295
0296 #else
0297 #define Z2_BATTERY_PM_OPS   (NULL)
0298 #endif
0299
0300 static const struct i2c_device_id z2_batt_id[] = {
0301     { "aer915", 0 },
0302     { }
0303 };
0304 MODULE_DEVICE_TABLE(i2c, z2_batt_id);
0305
0306 static struct i2c_driver z2_batt_driver = {
0307     .driver = {
0308         .name   = "z2-battery",
0309         .pm = Z2_BATTERY_PM_OPS
0310     },
0311     .probe      = z2_batt_probe,
0312     .remove     = z2_batt_remove,
0313     .id_table   = z2_batt_id,
0314 };
0315 module_i2c_driver(z2_batt_driver);
0316
0317 MODULE_LICENSE("GPL");
0318 MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>");
0319 MODULE_DESCRIPTION("Zipit Z2 battery driver");