drivers/power/supply/wm97xx_battery.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Battery measurement code for WM97xx
   4  *
   5  * based on tosa_battery.c
   6  *
   7  * Copyright (C) 2008 Marek Vasut <marek.vasut@gmail.com>
   8  */
   9
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/power_supply.h>
  15 #include <linux/wm97xx.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/gpio/consumer.h>
  19 #include <linux/irq.h>
  20 #include <linux/slab.h>
  21
  22 static struct work_struct bat_work;
  23 static struct gpio_desc *charge_gpiod;
  24 static DEFINE_MUTEX(work_lock);
  25 static int bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
  26 static enum power_supply_property *prop;
  27
  28 static unsigned long wm97xx_read_bat(struct power_supply *bat_ps)
  29 {
  30         struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
  31
  32         return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
  33                                         pdata->batt_aux) * pdata->batt_mult /
  34                                         pdata->batt_div;
  35 }
  36
  37 static unsigned long wm97xx_read_temp(struct power_supply *bat_ps)
  38 {
  39         struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
  40
  41         return wm97xx_read_aux_adc(dev_get_drvdata(bat_ps->dev.parent),
  42                                         pdata->temp_aux) * pdata->temp_mult /
  43                                         pdata->temp_div;
  44 }
  45
  46 static int wm97xx_bat_get_property(struct power_supply *bat_ps,
  47                             enum power_supply_property psp,
  48                             union power_supply_propval *val)
  49 {
  50         struct wm97xx_batt_pdata *pdata = power_supply_get_drvdata(bat_ps);
  51
  52         switch (psp) {
  53         case POWER_SUPPLY_PROP_STATUS:
  54                 val->intval = bat_status;
  55                 break;
  56         case POWER_SUPPLY_PROP_TECHNOLOGY:
  57                 val->intval = pdata->batt_tech;
  58                 break;
  59         case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  60                 if (pdata->batt_aux >= 0)
  61                         val->intval = wm97xx_read_bat(bat_ps);
  62                 else
  63                         return -EINVAL;
  64                 break;
  65         case POWER_SUPPLY_PROP_TEMP:
  66                 if (pdata->temp_aux >= 0)
  67                         val->intval = wm97xx_read_temp(bat_ps);
  68                 else
  69                         return -EINVAL;
  70                 break;
  71         case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  72                 if (pdata->max_voltage >= 0)
  73                         val->intval = pdata->max_voltage;
  74                 else
  75                         return -EINVAL;
  76                 break;
  77         case POWER_SUPPLY_PROP_VOLTAGE_MIN:
  78                 if (pdata->min_voltage >= 0)
  79                         val->intval = pdata->min_voltage;
  80                 else
  81                         return -EINVAL;
  82                 break;
  83         case POWER_SUPPLY_PROP_PRESENT:
  84                 val->intval = 1;
  85                 break;
  86         default:
  87                 return -EINVAL;
  88         }
  89         return 0;
  90 }
  91
  92 static void wm97xx_bat_external_power_changed(struct power_supply *bat_ps)
  93 {
  94         schedule_work(&bat_work);
  95 }
  96
  97 static void wm97xx_bat_update(struct power_supply *bat_ps)
  98 {
  99         int old_status = bat_status;
 100
 101         mutex_lock(&work_lock);
 102
 103         bat_status = (charge_gpiod) ?
 104                         (gpiod_get_value(charge_gpiod) ?
 105                         POWER_SUPPLY_STATUS_DISCHARGING :
 106                         POWER_SUPPLY_STATUS_CHARGING) :
 107                         POWER_SUPPLY_STATUS_UNKNOWN;
 108
 109         if (old_status != bat_status) {
 110                 pr_debug("%s: %i -> %i\n", bat_ps->desc->name, old_status,
 111                                         bat_status);
 112                 power_supply_changed(bat_ps);
 113         }
 114
 115         mutex_unlock(&work_lock);
 116 }
 117
 118 static struct power_supply *bat_psy;
 119 static struct power_supply_desc bat_psy_desc = {
 120         .type                   = POWER_SUPPLY_TYPE_BATTERY,
 121         .get_property           = wm97xx_bat_get_property,
 122         .external_power_changed = wm97xx_bat_external_power_changed,
 123         .use_for_apm            = 1,
 124 };
 125
 126 static void wm97xx_bat_work(struct work_struct *work)
 127 {
 128         wm97xx_bat_update(bat_psy);
 129 }
 130
 131 static irqreturn_t wm97xx_chrg_irq(int irq, void *data)
 132 {
 133         schedule_work(&bat_work);
 134         return IRQ_HANDLED;
 135 }
 136
 137 #ifdef CONFIG_PM
 138 static int wm97xx_bat_suspend(struct device *dev)
 139 {
 140         flush_work(&bat_work);
 141         return 0;
 142 }
 143
 144 static int wm97xx_bat_resume(struct device *dev)
 145 {
 146         schedule_work(&bat_work);
 147         return 0;
 148 }
 149
 150 static const struct dev_pm_ops wm97xx_bat_pm_ops = {
 151         .suspend        = wm97xx_bat_suspend,
 152         .resume         = wm97xx_bat_resume,
 153 };
 154 #endif
 155
 156 static int wm97xx_bat_probe(struct platform_device *dev)
 157 {
 158         int ret = 0;
 159         int props = 1;  /* POWER_SUPPLY_PROP_PRESENT */
 160         int i = 0;
 161         struct wm97xx_batt_pdata *pdata = dev->dev.platform_data;
 162         struct power_supply_config cfg = {};
 163
 164         if (!pdata) {
 165                 dev_err(&dev->dev, "No platform data supplied\n");
 166                 return -EINVAL;
 167         }
 168
 169         cfg.drv_data = pdata;
 170
 171         if (dev->id != -1)
 172                 return -EINVAL;
 173
 174         charge_gpiod = devm_gpiod_get_optional(&dev->dev, NULL, GPIOD_IN);
 175         if (IS_ERR(charge_gpiod))
 176                 return dev_err_probe(&dev->dev,
 177                                      PTR_ERR(charge_gpiod),
 178                                      "failed to get charge GPIO\n");
 179         if (charge_gpiod) {
 180                 gpiod_set_consumer_name(charge_gpiod, "BATT CHRG");
 181                 ret = request_irq(gpiod_to_irq(charge_gpiod),
 182                                 wm97xx_chrg_irq, 0,
 183                                 "AC Detect", dev);
 184                 if (ret)
 185                         return dev_err_probe(&dev->dev, ret,
 186                                              "failed to request GPIO irq\n");
 187                 props++;        /* POWER_SUPPLY_PROP_STATUS */
 188         }
 189
 190         if (pdata->batt_tech >= 0)
 191                 props++;        /* POWER_SUPPLY_PROP_TECHNOLOGY */
 192         if (pdata->temp_aux >= 0)
 193                 props++;        /* POWER_SUPPLY_PROP_TEMP */
 194         if (pdata->batt_aux >= 0)
 195                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
 196         if (pdata->max_voltage >= 0)
 197                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
 198         if (pdata->min_voltage >= 0)
 199                 props++;        /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
 200
 201         prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
 202         if (!prop) {
 203                 ret = -ENOMEM;
 204                 goto err3;
 205         }
 206
 207         prop[i++] = POWER_SUPPLY_PROP_PRESENT;
 208         if (charge_gpiod)
 209                 prop[i++] = POWER_SUPPLY_PROP_STATUS;
 210         if (pdata->batt_tech >= 0)
 211                 prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
 212         if (pdata->temp_aux >= 0)
 213                 prop[i++] = POWER_SUPPLY_PROP_TEMP;
 214         if (pdata->batt_aux >= 0)
 215                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
 216         if (pdata->max_voltage >= 0)
 217                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
 218         if (pdata->min_voltage >= 0)
 219                 prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
 220
 221         INIT_WORK(&bat_work, wm97xx_bat_work);
 222
 223         if (!pdata->batt_name) {
 224                 dev_info(&dev->dev, "Please consider setting proper battery "
 225                                 "name in platform definition file, falling "
 226                                 "back to name \"wm97xx-batt\"\n");
 227                 bat_psy_desc.name = "wm97xx-batt";
 228         } else
 229                 bat_psy_desc.name = pdata->batt_name;
 230
 231         bat_psy_desc.properties = prop;
 232         bat_psy_desc.num_properties = props;
 233
 234         bat_psy = power_supply_register(&dev->dev, &bat_psy_desc, &cfg);
 235         if (!IS_ERR(bat_psy)) {
 236                 schedule_work(&bat_work);
 237         } else {
 238                 ret = PTR_ERR(bat_psy);
 239                 goto err4;
 240         }
 241
 242         return 0;
 243 err4:
 244         kfree(prop);
 245 err3:
 246         if (charge_gpiod)
 247                 free_irq(gpiod_to_irq(charge_gpiod), dev);
 248         return ret;
 249 }
 250
 251 static int wm97xx_bat_remove(struct platform_device *dev)
 252 {
 253         if (charge_gpiod)
 254                 free_irq(gpiod_to_irq(charge_gpiod), dev);
 255         cancel_work_sync(&bat_work);
 256         power_supply_unregister(bat_psy);
 257         kfree(prop);
 258         return 0;
 259 }
 260
 261 static struct platform_driver wm97xx_bat_driver = {
 262         .driver = {
 263                 .name   = "wm97xx-battery",
 264 #ifdef CONFIG_PM
 265                 .pm     = &wm97xx_bat_pm_ops,
 266 #endif
 267         },
 268         .probe          = wm97xx_bat_probe,
 269         .remove         = wm97xx_bat_remove,
 270 };
 271
 272 module_platform_driver(wm97xx_bat_driver);
 273
 274 MODULE_LICENSE("GPL");
 275 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 276 MODULE_DESCRIPTION("WM97xx battery driver");