power/supply/wm97xx_battery.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Battery measurement code for WM97xx
0004  *
0005  * based on tosa_battery.c
0006  *
0007  * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
0008  */
0009
0010 #include <linux/init.h>
0011 #include <linux/kernel.h>
0012 #include <linux/module.h>
0013 #include <linux/platform_device.h>
0014 #include <linux/power_supply.h>
0015 #include <linux/wm97xx.h>
0016 #include <linux/spinlock.h>
0017 #include <linux/interrupt.h>
0018 #include <linux/gpio/consumer.h>
0019 #include <linux/irq.h>
0020 #include <linux/slab.h>
0021
0022 static struct work_struct bat_work;
0023 static struct gpio_desc *charge_gpiod;
0024 static DEFINE_MUTEX(work_lock);
0025 static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
0026 static enum power_supply_property *prop;
0027
0028 static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
0029 {
0030     struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
0031
0032     return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
0033                     pdata->batt_aux) * pdata->batt_mult /
0034                     pdata->batt_div;
0035 }
0036
0037 static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
0038 {
0039     struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
0040
0041     return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
0042                     pdata->temp_aux) * pdata->temp_mult /
0043                     pdata->temp_div;
0044 }
0045
0046 static int wm97xx_bat_get_property(struct power_supply *bat_ps,
0047                 enum power_supply_property psp,
0048                 union power_supply_propval *val)
0049 {
0050     struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
0051
0052     switch (psp) {
0053     case POWER_SUPPLY_PROP_STATUS:
0054         val->intval = bat_status;
0055         break;
0056     case POWER_SUPPLY_PROP_TECHNOLOGY:
0057         val->intval = pdata->batt_tech;
0058         break;
0059     case POWER_SUPPLY_PROP_VOLTAGE_NOW:
0060         if (pdata->batt_aux >= 0)
0061             val->intval = wm97xx_read_bat(bat_ps);
0062         else
0063             return -EINVAL;
0064         break;
0065     case POWER_SUPPLY_PROP_TEMP:
0066         if (pdata->temp_aux >= 0)
0067             val->intval = wm97xx_read_temp(bat_ps);
0068         else
0069             return -EINVAL;
0070         break;
0071     case POWER_SUPPLY_PROP_VOLTAGE_MAX:
0072         if (pdata->max_voltage >= 0)
0073             val->intval = pdata->max_voltage;
0074         else
0075             return -EINVAL;
0076         break;
0077     case POWER_SUPPLY_PROP_VOLTAGE_MIN:
0078         if (pdata->min_voltage >= 0)
0079             val->intval = pdata->min_voltage;
0080         else
0081             return -EINVAL;
0082         break;
0083     case POWER_SUPPLY_PROP_PRESENT:
0084         val->intval = 1;
0085         break;
0086     default:
0087         return -EINVAL;
0088     }
0089     return 0;
0090 }
0091
0092 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
0093 {
0094     schedule_work(&bat_work);
0095 }
0096
0097 static void wm97xx_bat_update(struct power_supply *bat_ps)
0098 {
0099     int old_status = bat_status;
0100
0101     mutex_lock(&work_lock);
0102
0103     bat_status = (charge_gpiod) ?
0104             (gpiod_get_value(charge_gpiod) ?
0105             POWER_SUPPLY_STATUS_DISCHARGING :
0106             POWER_SUPPLY_STATUS_CHARGING) :
0107             POWER_SUPPLY_STATUS_UNKNOWN;
0108
0109     if (old_status != bat_status) {
0110         pr_debug("%s: %i -> %i\n", bat_ps->desc->name, old_status,
0111                     bat_status);
0112         power_supply_changed(bat_ps);
0113     }
0114
0115     mutex_unlock(&work_lock);
0116 }
0117
0118 static struct power_supply *bat_psy;
0119 static struct power_supply_desc bat_psy_desc = {
0120     .type           = POWER_SUPPLY_TYPE_BATTERY,
0121     .get_property       = wm97xx_bat_get_property,
0122     .external_power_changed = wm97xx_bat_external_power_changed,
0123     .use_for_apm        = 1,
0124 };
0125
0126 static void wm97xx_bat_work(struct work_struct *work)
0127 {
0128     wm97xx_bat_update(bat_psy);
0129 }
0130
0131 static irqreturn_t wm97xx_chrg_irq(int irq, void *data)
0132 {
0133     schedule_work(&bat_work);
0134     return IRQ_HANDLED;
0135 }
0136
0137 #ifdef CONFIG_PM
0138 static int wm97xx_bat_suspend(struct device *dev)
0139 {
0140     flush_work(&bat_work);
0141     return 0;
0142 }
0143
0144 static int wm97xx_bat_resume(struct device *dev)
0145 {
0146     schedule_work(&bat_work);
0147     return 0;
0148 }
0149
0150 static const struct dev_pm_ops wm97xx_bat_pm_ops = {
0151     .suspend    = wm97xx_bat_suspend,
0152     .resume     = wm97xx_bat_resume,
0153 };
0154 #endif
0155
0156 static int wm97xx_bat_probe(struct platform_device *dev)
0157 {
0158     int ret = 0;
0159     int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
0160     int i = 0;
0161     struct wm97xx_batt_pdata *pdata = dev->dev.platform_data;
0162     struct power_supply_config cfg = {};
0163
0164     if (!pdata) {
0165         dev_err(&dev->dev, "No platform data supplied\n");
0166         return -EINVAL;
0167     }
0168
0169     cfg.drv_data = pdata;
0170
0171     if (dev->id != -1)
0172         return -EINVAL;
0173
0174     charge_gpiod = devm_gpiod_get_optional(&dev->dev, NULL, GPIOD_IN);
0175     if (IS_ERR(charge_gpiod))
0176         return dev_err_probe(&dev->dev,
0177                      PTR_ERR(charge_gpiod),
0178                      "failed to get charge GPIO\n");
0179     if (charge_gpiod) {
0180         gpiod_set_consumer_name(charge_gpiod, "BATT CHRG");
0181         ret = request_irq(gpiod_to_irq(charge_gpiod),
0182                 wm97xx_chrg_irq, 0,
0183                 "AC Detect", dev);
0184         if (ret)
0185             return dev_err_probe(&dev->dev, ret,
0186                          "failed to request GPIO irq\n");
0187         props++;    /* POWER_SUPPLY_PROP_STATUS */
0188     }
0189
0190     if (pdata->batt_tech >= 0)
0191         props++;    /* POWER_SUPPLY_PROP_TECHNOLOGY */
0192     if (pdata->temp_aux >= 0)
0193         props++;    /* POWER_SUPPLY_PROP_TEMP */
0194     if (pdata->batt_aux >= 0)
0195         props++;    /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
0196     if (pdata->max_voltage >= 0)
0197         props++;    /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
0198     if (pdata->min_voltage >= 0)
0199         props++;    /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
0200
0201     prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
0202     if (!prop) {
0203         ret = -ENOMEM;
0204         goto err3;
0205     }
0206
0207     prop[i++] = POWER_SUPPLY_PROP_PRESENT;
0208     if (charge_gpiod)
0209         prop[i++] = POWER_SUPPLY_PROP_STATUS;
0210     if (pdata->batt_tech >= 0)
0211         prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
0212     if (pdata->temp_aux >= 0)
0213         prop[i++] = POWER_SUPPLY_PROP_TEMP;
0214     if (pdata->batt_aux >= 0)
0215         prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
0216     if (pdata->max_voltage >= 0)
0217         prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
0218     if (pdata->min_voltage >= 0)
0219         prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
0220
0221     INIT_WORK(&bat_work, wm97xx_bat_work);
0222
0223     if (!pdata->batt_name) {
0224         dev_info(&dev->dev, "Please consider setting proper battery "
0225                 "name in platform definition file, falling "
0226                 "back to name \"wm97xx-batt\"\n");
0227         bat_psy_desc.name = "wm97xx-batt";
0228     } else
0229         bat_psy_desc.name = pdata->batt_name;
0230
0231     bat_psy_desc.properties = prop;
0232     bat_psy_desc.num_properties = props;
0233
0234     bat_psy = power_supply_register(&dev->dev, &bat_psy_desc, &cfg);
0235     if (!IS_ERR(bat_psy)) {
0236         schedule_work(&bat_work);
0237     } else {
0238         ret = PTR_ERR(bat_psy);
0239         goto err4;
0240     }
0241
0242     return 0;
0243 err4:
0244     kfree(prop);
0245 err3:
0246     if (charge_gpiod)
0247         free_irq(gpiod_to_irq(charge_gpiod), dev);
0248     return ret;
0249 }
0250
0251 static int wm97xx_bat_remove(struct platform_device *dev)
0252 {
0253     if (charge_gpiod)
0254         free_irq(gpiod_to_irq(charge_gpiod), dev);
0255     cancel_work_sync(&bat_work);
0256     power_supply_unregister(bat_psy);
0257     kfree(prop);
0258     return 0;
0259 }
0260
0261 static struct platform_driver wm97xx_bat_driver = {
0262     .driver = {
0263         .name   = "wm97xx-battery",
0264 #ifdef CONFIG_PM
0265         .pm = &wm97xx_bat_pm_ops,
0266 #endif
0267     },
0268     .probe      = wm97xx_bat_probe,
0269     .remove     = wm97xx_bat_remove,
0270 };
0271
0272 module_platform_driver(wm97xx_bat_driver);
0273
0274 MODULE_LICENSE("GPL");
0275 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
0276 MODULE_DESCRIPTION("WM97xx battery driver");