Quelle  tps65217_charger.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
// Battery charger driver for TI's tps65217
//
// Copyright (C) 2015 Collabora Ltd.
// Author: Enric Balletbo i Serra <enric.balletbo@collabora.com>

/*
 * Battery charger driver for TI's tps65217
 */
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/power_supply.h>

#include <linux/mfd/core.h>
#include <linux/mfd/tps65217.h>

#define CHARGER_STATUS_PRESENT (TPS65217_STATUS_ACPWR | TPS65217_STATUS_USBPWR)
#define NUM_CHARGER_IRQS 2
#define POLL_INTERVAL  (HZ * 2)

struct tps65217_charger {
 struct tps65217 *tps;
 struct device *dev;
 struct power_supply *psy;

 int online;
 int prev_online;

 struct task_struct *poll_task;
};

static enum power_supply_property tps65217_charger_props[] = {
 POWER_SUPPLY_PROP_ONLINE,
};

static int tps65217_config_charger(struct tps65217_charger *charger)
{
 int ret;

 /*
 * tps65217 rev. G, p. 31 (see p. 32 for NTC schematic)
 *
 * The device can be configured to support a 100k NTC (B = 3960) by
 * setting the NTC_TYPE bit in register CHGCONFIG1 to 1. However it
 * is not recommended to do so. In sleep mode, the charger continues
 * charging the battery, but all register values are reset to default
 * values. Therefore, the charger would get the wrong temperature
 * information. If 100k NTC setting is required, please contact the
 * factory.
 *
 * ATTENTION, conflicting information, from p. 46
 *
 * NTC TYPE (for battery temperature measurement)
 *   0 – 100k (curve 1, B = 3960)
 *   1 – 10k  (curve 2, B = 3480) (default on reset)
 *
 */
 ret = tps65217_clear_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
      TPS65217_CHGCONFIG1_NTC_TYPE,
      TPS65217_PROTECT_NONE);
 if (ret) {
  dev_err(charger->dev,
   "failed to set 100k NTC setting: %d\n", ret);
  return ret;
 }

 return 0;
}

static int tps65217_enable_charging(struct tps65217_charger *charger)
{
 int ret;

 /* charger already enabled */
 if (charger->online)
  return 0;

 dev_dbg(charger->dev, "%s: enable charging\n", __func__);
 ret = tps65217_set_bits(charger->tps, TPS65217_REG_CHGCONFIG1,
    TPS65217_CHGCONFIG1_CHG_EN,
    TPS65217_CHGCONFIG1_CHG_EN,
    TPS65217_PROTECT_NONE);
 if (ret) {
  dev_err(charger->dev,
   "%s: Error in writing CHG_EN in reg 0x%x: %d\n",
   __func__, TPS65217_REG_CHGCONFIG1, ret);
  return ret;
 }

 charger->online = 1;

 return 0;
}

static int tps65217_charger_get_property(struct power_supply *psy,
      enum power_supply_property psp,
      union power_supply_propval *val)
{
 struct tps65217_charger *charger = power_supply_get_drvdata(psy);

 if (psp == POWER_SUPPLY_PROP_ONLINE) {
  val->intval = charger->online;
  return 0;
 }
 return -EINVAL;
}

static irqreturn_t tps65217_charger_irq(int irq, void *dev)
{
 int ret, val;
 struct tps65217_charger *charger = dev;

 charger->prev_online = charger->online;

 ret = tps65217_reg_read(charger->tps, TPS65217_REG_STATUS, &val);
 if (ret < 0) {
  dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
   __func__, TPS65217_REG_STATUS);
  return IRQ_HANDLED;
 }

 dev_dbg(charger->dev, "%s: 0x%x\n", __func__, val);

 /* check for charger status bit */
 if (val & CHARGER_STATUS_PRESENT) {
  ret = tps65217_enable_charging(charger);
  if (ret) {
   dev_err(charger->dev,
    "failed to enable charger: %d\n", ret);
   return IRQ_HANDLED;
  }
 } else {
  charger->online = 0;
 }

 if (charger->prev_online != charger->online)
  power_supply_changed(charger->psy);

 ret = tps65217_reg_read(charger->tps, TPS65217_REG_CHGCONFIG0, &val);
 if (ret < 0) {
  dev_err(charger->dev, "%s: Error in reading reg 0x%x\n",
   __func__, TPS65217_REG_CHGCONFIG0);
  return IRQ_HANDLED;
 }

 if (val & TPS65217_CHGCONFIG0_ACTIVE)
  dev_dbg(charger->dev, "%s: charger is charging\n", __func__);
 else
  dev_dbg(charger->dev,
   "%s: charger is NOT charging\n", __func__);

 return IRQ_HANDLED;
}

static int tps65217_charger_poll_task(void *data)
{
 set_freezable();

 while (!kthread_should_stop()) {
  schedule_timeout_interruptible(POLL_INTERVAL);
  try_to_freeze();
  tps65217_charger_irq(-1, data);
 }
 return 0;
}

static const struct power_supply_desc tps65217_charger_desc = {
 .name   = "tps65217-charger",
 .type   = POWER_SUPPLY_TYPE_MAINS,
 .get_property  = tps65217_charger_get_property,
 .properties  = tps65217_charger_props,
 .num_properties  = ARRAY_SIZE(tps65217_charger_props),
};

static int tps65217_charger_probe(struct platform_device *pdev)
{
 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
 struct tps65217_charger *charger;
 struct power_supply_config cfg = {};
 struct task_struct *poll_task;
 int irq[NUM_CHARGER_IRQS];
 int ret;
 int i;

 charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
 if (!charger)
  return -ENOMEM;

 platform_set_drvdata(pdev, charger);
 charger->tps = tps;
 charger->dev = &pdev->dev;

 cfg.fwnode = dev_fwnode(&pdev->dev);
 cfg.drv_data = charger;

 charger->psy = devm_power_supply_register(&pdev->dev,
        &tps65217_charger_desc,
        &cfg);
 if (IS_ERR(charger->psy)) {
  dev_err(&pdev->dev, "failed: power supply register\n");
  return PTR_ERR(charger->psy);
 }

 irq[0] = platform_get_irq_byname(pdev, "USB");
 irq[1] = platform_get_irq_byname(pdev, "AC");

 ret = tps65217_config_charger(charger);
 if (ret < 0) {
  dev_err(charger->dev, "charger config failed, err %d\n", ret);
  return ret;
 }

 /* Create a polling thread if an interrupt is invalid */
 if (irq[0] < 0 || irq[1] < 0) {
  poll_task = kthread_run(tps65217_charger_poll_task,
     charger, "ktps65217charger");
  if (IS_ERR(poll_task)) {
   ret = PTR_ERR(poll_task);
   dev_err(charger->dev,
    "Unable to run kthread err %d\n", ret);
   return ret;
  }

  charger->poll_task = poll_task;
  return 0;
 }

 /* Create IRQ threads for charger interrupts */
 for (i = 0; i < NUM_CHARGER_IRQS; i++) {
  ret = devm_request_threaded_irq(&pdev->dev, irq[i], NULL,
      tps65217_charger_irq,
      IRQF_SHARED, "tps65217-charger",
      charger);
  if (ret) {
   dev_err(charger->dev,
    "Unable to register irq %d err %d\n", irq[i],
    ret);
   return ret;
  }

  /* Check current state */
  tps65217_charger_irq(-1, charger);
 }

 return 0;
}

static void tps65217_charger_remove(struct platform_device *pdev)
{
 struct tps65217_charger *charger = platform_get_drvdata(pdev);

 if (charger->poll_task)
  kthread_stop(charger->poll_task);
}

static const struct of_device_id tps65217_charger_match_table[] = {
 { .compatible = "ti,tps65217-charger", },
 { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, tps65217_charger_match_table);

static struct platform_driver tps65217_charger_driver = {
 .probe = tps65217_charger_probe,
 .remove = tps65217_charger_remove,
 .driver = {
  .name = "tps65217-charger",
  .of_match_table = of_match_ptr(tps65217_charger_match_table),
 },

};
module_platform_driver(tps65217_charger_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Enric Balletbo Serra ");
MODULE_DESCRIPTION("TPS65217 battery charger driver");