drivers/power/tps65217_charger.c

   1 /*
   2  * Battery charger driver for TI's tps65217
   3  *
   4  * Copyright (c) 2015, Collabora Ltd.
   5
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 /*
  20  * Battery charger driver for TI's tps65217
  21  */
  22 #include <linux/kernel.h>
  23 #include <linux/kthread.h>
  24 #include <linux/device.h>
  25 #include <linux/module.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/init.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/slab.h>
  30 #include <linux/err.h>
  31 #include <linux/of.h>
  32 #include <linux/of_device.h>
  33 #include <linux/power_supply.h>
  34
  35 #include <linux/mfd/core.h>
  36 #include <linux/mfd/tps65217.h>
  37
  38 #define POLL_INTERVAL           (HZ * 2)
  39
  40 struct tps65217_charger {
  41         struct tps65217 *tps;
  42         struct device *dev;
  43         struct power_supply *ac;
  44
  45         int     ac_online;
  46         int     prev_ac_online;
  47
  48         struct task_struct      *poll_task;
  49 };
  50
  51 static enum power_supply_property tps65217_ac_props[] = {
  52         POWER_SUPPLY_PROP_ONLINE,
  53 };
  54
  55 static int tps65217_config_charger(struct tps65217_charger *charger)
  56 {
  57         int ret;
  58
  59         dev_dbg(charger->dev, "%s\n", __func__);
  60
  61         /*
  62          * tps65217 rev. G, p. 31 (see p. 32 for NTC schematic)
  63          *
  64          * The device can be configured to support a 100k NTC (B = 3960) by
  65          * setting the the NTC_TYPE bit in register CHGCONFIG1 to 1. However it
  66          * is not recommended to do so. In sleep mode, the charger continues
  67          * charging the battery, but all register values are reset to default
  68          * values. Therefore, the charger would get the wrong temperature
  69          * information. If 100k NTC setting is required, please contact the
  70          * factory.
  71          *
  72          * ATTENTION, conflicting information, from p. 46
  73          *
  74          * NTC TYPE (for battery temperature measurement)
  75          *   0 – 100k (curve 1, B = 3960)
  76          *   1 – 10k  (curve 2, B = 3480) (default on reset)
  77          *
  78          */
  79         ret = tps65217_clear_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
  80                                   TPS65217_CHGCONFIG1_NTC_TYPE,
  81                                   TPS65217_PROTECT_NONE);
  82         if (ret) {
  83                 dev_err(charger->dev,
  84                         "failed to set 100k NTC setting: %d\n", ret);
  85                 return ret;
  86         }
  87
  88         return 0;
  89 }
  90
  91 static int tps65217_enable_charging(struct tps65217_charger *charger)
  92 {
  93         int ret;
  94
  95         /* charger already enabled */
  96         if (charger->ac_online)
  97                 return 0;
  98
  99         dev_dbg(charger->dev, "%s: enable charging\n", __func__);
 100         ret = tps65217_set_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
 101                                 TPS65217_CHGCONFIG1_CHG_EN,
 102                                 TPS65217_CHGCONFIG1_CHG_EN,
 103                                 TPS65217_PROTECT_NONE);
 104         if (ret) {
 105                 dev_err(charger->dev,
 106                         "%s: Error in writing CHG_EN in reg 0x%x: %d\n",
 107                         __func__, TPS65217_REG_CHGCONFIG1, ret);
 108                 return ret;
 109         }
 110
 111         charger->ac_online = 1;
 112
 113         return 0;
 114 }
 115
 116 static int tps65217_ac_get_property(struct power_supply *psy,
 117                         enum power_supply_property psp,
 118                         union power_supply_propval *val)
 119 {
 120         struct tps65217_charger *charger = power_supply_get_drvdata(psy);
 121
 122         if (psp == POWER_SUPPLY_PROP_ONLINE) {
 123                 val->intval = charger->ac_online;
 124                 return 0;
 125         }
 126         return -EINVAL;
 127 }
 128
 129 static irqreturn_t tps65217_charger_irq(int irq, void *dev)
 130 {
 131         int ret, val;
 132         struct tps65217_charger *charger = dev;
 133
 134         charger->prev_ac_online = charger->ac_online;
 135
 136         ret = tps65217_reg_read(charger->tps, TPS65217_REG_STATUS, &val);
 137         if (ret < 0) {
 138                 dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
 139                         __func__, TPS65217_REG_STATUS);
 140                 return IRQ_HANDLED;
 141         }
 142
 143         dev_dbg(charger->dev, "%s: 0x%x\n", __func__, val);
 144
 145         /* check for AC status bit */
 146         if (val & TPS65217_STATUS_ACPWR) {
 147                 ret = tps65217_enable_charging(charger);
 148                 if (ret) {
 149                         dev_err(charger->dev,
 150                                 "failed to enable charger: %d\n", ret);
 151                         return IRQ_HANDLED;
 152                 }
 153         } else {
 154                 charger->ac_online = 0;
 155         }
 156
 157         if (charger->prev_ac_online != charger->ac_online)
 158                 power_supply_changed(charger->ac);
 159
 160         ret = tps65217_reg_read(charger->tps, TPS65217_REG_CHGCONFIG0, &val);
 161         if (ret < 0) {
 162                 dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
 163                         __func__, TPS65217_REG_CHGCONFIG0);
 164                 return IRQ_HANDLED;
 165         }
 166
 167         if (val & TPS65217_CHGCONFIG0_ACTIVE)
 168                 dev_dbg(charger->dev, "%s: charger is charging\n", __func__);
 169         else
 170                 dev_dbg(charger->dev,
 171                         "%s: charger is NOT charging\n", __func__);
 172
 173         return IRQ_HANDLED;
 174 }
 175
 176 static int tps65217_charger_poll_task(void *data)
 177 {
 178         set_freezable();
 179
 180         while (!kthread_should_stop()) {
 181                 schedule_timeout_interruptible(POLL_INTERVAL);
 182                 try_to_freeze();
 183                 tps65217_charger_irq(-1, data);
 184         }
 185         return 0;
 186 }
 187
 188 static const struct power_supply_desc tps65217_charger_desc = {
 189         .name                   = "tps65217-ac",
 190         .type                   = POWER_SUPPLY_TYPE_MAINS,
 191         .get_property           = tps65217_ac_get_property,
 192         .properties             = tps65217_ac_props,
 193         .num_properties         = ARRAY_SIZE(tps65217_ac_props),
 194 };
 195
 196 static int tps65217_charger_probe(struct platform_device *pdev)
 197 {
 198         struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
 199         struct tps65217_charger *charger;
 200         int ret;
 201
 202         dev_dbg(&pdev->dev, "%s\n", __func__);
 203
 204         charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
 205         if (!charger)
 206                 return -ENOMEM;
 207
 208         charger->tps = tps;
 209         charger->dev = &pdev->dev;
 210
 211         charger->ac = devm_power_supply_register(&pdev->dev,
 212                                                  &tps65217_charger_desc,
 213                                                  NULL);
 214         if (IS_ERR(charger->ac)) {
 215                 dev_err(&pdev->dev, "failed: power supply register\n");
 216                 return PTR_ERR(charger->ac);
 217         }
 218
 219         ret = tps65217_config_charger(charger);
 220         if (ret < 0) {
 221                 dev_err(charger->dev, "charger config failed, err %d\n", ret);
 222                 return ret;
 223         }
 224
 225         charger->poll_task = kthread_run(tps65217_charger_poll_task,
 226                                       charger, "ktps65217charger");
 227         if (IS_ERR(charger->poll_task)) {
 228                 ret = PTR_ERR(charger->poll_task);
 229                 dev_err(charger->dev, "Unable to run kthread err %d\n", ret);
 230                 return ret;
 231         }
 232
 233         return 0;
 234 }
 235
 236 static int tps65217_charger_remove(struct platform_device *pdev)
 237 {
 238         struct tps65217_charger *charger = platform_get_drvdata(pdev);
 239
 240         kthread_stop(charger->poll_task);
 241
 242         return 0;
 243 }
 244
 245 static const struct of_device_id tps65217_charger_match_table[] = {
 246         { .compatible = "ti,tps65217-charger", },
 247         { /* sentinel */ }
 248 };
 249 MODULE_DEVICE_TABLE(of, tps65217_charger_match_table);
 250
 251 static struct platform_driver tps65217_charger_driver = {
 252         .probe  = tps65217_charger_probe,
 253         .remove = tps65217_charger_remove,
 254         .driver = {
 255                 .name   = "tps65217-charger",
 256                 .of_match_table = of_match_ptr(tps65217_charger_match_table),
 257         },
 258
 259 };
 260 module_platform_driver(tps65217_charger_driver);
 261
 262 MODULE_LICENSE("GPL v2");
 263 MODULE_AUTHOR("Enric Balletbo Serra <enric.balletbo@collabora.com>");
 264 MODULE_DESCRIPTION("TPS65217 battery charger driver");