linux/drivers/power/supply/tps65217_charger.c
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   1// SPDX-License-Identifier: GPL-2.0
   2// Battery charger driver for TI's tps65217
   3//
   4// Copyright (C) 2015 Collabora Ltd.
   5// Author: Enric Balletbo i Serra <enric.balletbo@collabora.com>
   6
   7/*
   8 * Battery charger driver for TI's tps65217
   9 */
  10#include <linux/kernel.h>
  11#include <linux/kthread.h>
  12#include <linux/device.h>
  13#include <linux/module.h>
  14#include <linux/platform_device.h>
  15#include <linux/init.h>
  16#include <linux/interrupt.h>
  17#include <linux/slab.h>
  18#include <linux/err.h>
  19#include <linux/of.h>
  20#include <linux/of_device.h>
  21#include <linux/power_supply.h>
  22
  23#include <linux/mfd/core.h>
  24#include <linux/mfd/tps65217.h>
  25
  26#define CHARGER_STATUS_PRESENT  (TPS65217_STATUS_ACPWR | TPS65217_STATUS_USBPWR)
  27#define NUM_CHARGER_IRQS        2
  28#define POLL_INTERVAL           (HZ * 2)
  29
  30struct tps65217_charger {
  31        struct tps65217 *tps;
  32        struct device *dev;
  33        struct power_supply *psy;
  34
  35        int     online;
  36        int     prev_online;
  37
  38        struct task_struct      *poll_task;
  39};
  40
  41static enum power_supply_property tps65217_charger_props[] = {
  42        POWER_SUPPLY_PROP_ONLINE,
  43};
  44
  45static int tps65217_config_charger(struct tps65217_charger *charger)
  46{
  47        int ret;
  48
  49        /*
  50         * tps65217 rev. G, p. 31 (see p. 32 for NTC schematic)
  51         *
  52         * The device can be configured to support a 100k NTC (B = 3960) by
  53         * setting the the NTC_TYPE bit in register CHGCONFIG1 to 1. However it
  54         * is not recommended to do so. In sleep mode, the charger continues
  55         * charging the battery, but all register values are reset to default
  56         * values. Therefore, the charger would get the wrong temperature
  57         * information. If 100k NTC setting is required, please contact the
  58         * factory.
  59         *
  60         * ATTENTION, conflicting information, from p. 46
  61         *
  62         * NTC TYPE (for battery temperature measurement)
  63         *   0 – 100k (curve 1, B = 3960)
  64         *   1 – 10k  (curve 2, B = 3480) (default on reset)
  65         *
  66         */
  67        ret = tps65217_clear_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
  68                                  TPS65217_CHGCONFIG1_NTC_TYPE,
  69                                  TPS65217_PROTECT_NONE);
  70        if (ret) {
  71                dev_err(charger->dev,
  72                        "failed to set 100k NTC setting: %d\n", ret);
  73                return ret;
  74        }
  75
  76        return 0;
  77}
  78
  79static int tps65217_enable_charging(struct tps65217_charger *charger)
  80{
  81        int ret;
  82
  83        /* charger already enabled */
  84        if (charger->online)
  85                return 0;
  86
  87        dev_dbg(charger->dev, "%s: enable charging\n", __func__);
  88        ret = tps65217_set_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
  89                                TPS65217_CHGCONFIG1_CHG_EN,
  90                                TPS65217_CHGCONFIG1_CHG_EN,
  91                                TPS65217_PROTECT_NONE);
  92        if (ret) {
  93                dev_err(charger->dev,
  94                        "%s: Error in writing CHG_EN in reg 0x%x: %d\n",
  95                        __func__, TPS65217_REG_CHGCONFIG1, ret);
  96                return ret;
  97        }
  98
  99        charger->online = 1;
 100
 101        return 0;
 102}
 103
 104static int tps65217_charger_get_property(struct power_supply *psy,
 105                                         enum power_supply_property psp,
 106                                         union power_supply_propval *val)
 107{
 108        struct tps65217_charger *charger = power_supply_get_drvdata(psy);
 109
 110        if (psp == POWER_SUPPLY_PROP_ONLINE) {
 111                val->intval = charger->online;
 112                return 0;
 113        }
 114        return -EINVAL;
 115}
 116
 117static irqreturn_t tps65217_charger_irq(int irq, void *dev)
 118{
 119        int ret, val;
 120        struct tps65217_charger *charger = dev;
 121
 122        charger->prev_online = charger->online;
 123
 124        ret = tps65217_reg_read(charger->tps, TPS65217_REG_STATUS, &val);
 125        if (ret < 0) {
 126                dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
 127                        __func__, TPS65217_REG_STATUS);
 128                return IRQ_HANDLED;
 129        }
 130
 131        dev_dbg(charger->dev, "%s: 0x%x\n", __func__, val);
 132
 133        /* check for charger status bit */
 134        if (val & CHARGER_STATUS_PRESENT) {
 135                ret = tps65217_enable_charging(charger);
 136                if (ret) {
 137                        dev_err(charger->dev,
 138                                "failed to enable charger: %d\n", ret);
 139                        return IRQ_HANDLED;
 140                }
 141        } else {
 142                charger->online = 0;
 143        }
 144
 145        if (charger->prev_online != charger->online)
 146                power_supply_changed(charger->psy);
 147
 148        ret = tps65217_reg_read(charger->tps, TPS65217_REG_CHGCONFIG0, &val);
 149        if (ret < 0) {
 150                dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
 151                        __func__, TPS65217_REG_CHGCONFIG0);
 152                return IRQ_HANDLED;
 153        }
 154
 155        if (val & TPS65217_CHGCONFIG0_ACTIVE)
 156                dev_dbg(charger->dev, "%s: charger is charging\n", __func__);
 157        else
 158                dev_dbg(charger->dev,
 159                        "%s: charger is NOT charging\n", __func__);
 160
 161        return IRQ_HANDLED;
 162}
 163
 164static int tps65217_charger_poll_task(void *data)
 165{
 166        set_freezable();
 167
 168        while (!kthread_should_stop()) {
 169                schedule_timeout_interruptible(POLL_INTERVAL);
 170                try_to_freeze();
 171                tps65217_charger_irq(-1, data);
 172        }
 173        return 0;
 174}
 175
 176static const struct power_supply_desc tps65217_charger_desc = {
 177        .name                   = "tps65217-charger",
 178        .type                   = POWER_SUPPLY_TYPE_MAINS,
 179        .get_property           = tps65217_charger_get_property,
 180        .properties             = tps65217_charger_props,
 181        .num_properties         = ARRAY_SIZE(tps65217_charger_props),
 182};
 183
 184static int tps65217_charger_probe(struct platform_device *pdev)
 185{
 186        struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
 187        struct tps65217_charger *charger;
 188        struct power_supply_config cfg = {};
 189        struct task_struct *poll_task;
 190        int irq[NUM_CHARGER_IRQS];
 191        int ret;
 192        int i;
 193
 194        charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
 195        if (!charger)
 196                return -ENOMEM;
 197
 198        platform_set_drvdata(pdev, charger);
 199        charger->tps = tps;
 200        charger->dev = &pdev->dev;
 201
 202        cfg.of_node = pdev->dev.of_node;
 203        cfg.drv_data = charger;
 204
 205        charger->psy = devm_power_supply_register(&pdev->dev,
 206                                                  &tps65217_charger_desc,
 207                                                  &cfg);
 208        if (IS_ERR(charger->psy)) {
 209                dev_err(&pdev->dev, "failed: power supply register\n");
 210                return PTR_ERR(charger->psy);
 211        }
 212
 213        irq[0] = platform_get_irq_byname(pdev, "USB");
 214        irq[1] = platform_get_irq_byname(pdev, "AC");
 215
 216        ret = tps65217_config_charger(charger);
 217        if (ret < 0) {
 218                dev_err(charger->dev, "charger config failed, err %d\n", ret);
 219                return ret;
 220        }
 221
 222        /* Create a polling thread if an interrupt is invalid */
 223        if (irq[0] < 0 || irq[1] < 0) {
 224                poll_task = kthread_run(tps65217_charger_poll_task,
 225                                        charger, "ktps65217charger");
 226                if (IS_ERR(poll_task)) {
 227                        ret = PTR_ERR(poll_task);
 228                        dev_err(charger->dev,
 229                                "Unable to run kthread err %d\n", ret);
 230                        return ret;
 231                }
 232
 233                charger->poll_task = poll_task;
 234                return 0;
 235        }
 236
 237        /* Create IRQ threads for charger interrupts */
 238        for (i = 0; i < NUM_CHARGER_IRQS; i++) {
 239                ret = devm_request_threaded_irq(&pdev->dev, irq[i], NULL,
 240                                                tps65217_charger_irq,
 241                                                0, "tps65217-charger",
 242                                                charger);
 243                if (ret) {
 244                        dev_err(charger->dev,
 245                                "Unable to register irq %d err %d\n", irq[i],
 246                                ret);
 247                        return ret;
 248                }
 249
 250                /* Check current state */
 251                tps65217_charger_irq(-1, charger);
 252        }
 253
 254        return 0;
 255}
 256
 257static int tps65217_charger_remove(struct platform_device *pdev)
 258{
 259        struct tps65217_charger *charger = platform_get_drvdata(pdev);
 260
 261        if (charger->poll_task)
 262                kthread_stop(charger->poll_task);
 263
 264        return 0;
 265}
 266
 267static const struct of_device_id tps65217_charger_match_table[] = {
 268        { .compatible = "ti,tps65217-charger", },
 269        { /* sentinel */ }
 270};
 271MODULE_DEVICE_TABLE(of, tps65217_charger_match_table);
 272
 273static struct platform_driver tps65217_charger_driver = {
 274        .probe  = tps65217_charger_probe,
 275        .remove = tps65217_charger_remove,
 276        .driver = {
 277                .name   = "tps65217-charger",
 278                .of_match_table = of_match_ptr(tps65217_charger_match_table),
 279        },
 280
 281};
 282module_platform_driver(tps65217_charger_driver);
 283
 284MODULE_LICENSE("GPL v2");
 285MODULE_AUTHOR("Enric Balletbo Serra <enric.balletbo@collabora.com>");
 286MODULE_DESCRIPTION("TPS65217 battery charger driver");
 287