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linux/drivers/power/supply/max8997_charger.c
Dan Carpenter 58e4a2d27d extcon: Fix extcon_get_extcon_dev() error handling 
The extcon_get_extcon_dev() function returns error pointers on error,
NULL when it's a -EPROBE_DEFER defer situation, and ERR_PTR(-ENODEV)
when the CONFIG_EXTCON option is disabled.  This is very complicated for
the callers to handle and a number of them had bugs that would lead to
an Oops.

In real life, there are two things which prevented crashes.  First,
error pointers would only be returned if there was bug in the caller
where they passed a NULL "extcon_name" and none of them do that.
Second, only two out of the eight drivers will build when CONFIG_EXTCON
is disabled.

The normal way to write this would be to return -EPROBE_DEFER directly
when appropriate and return NULL when CONFIG_EXTCON is disabled.  Then
the error handling is simple and just looks like:

	dev->edev = extcon_get_extcon_dev(acpi_dev_name(adev));
	if (IS_ERR(dev->edev))
		return PTR_ERR(dev->edev);

For the two drivers which can build with CONFIG_EXTCON disabled, then
extcon_get_extcon_dev() will now return NULL which is not treated as an
error and the probe will continue successfully.  Those two drivers are
"typec_fusb302" and "max8997-battery".  In the original code, the
typec_fusb302 driver had an 800ms hang in tcpm_get_current_limit() but
now that function is a no-op.  For the max8997-battery driver everything
should continue working as is.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
2022-05-13 17:03:40 +09:00

288 lines
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// SPDX-License-Identifier: GPL-2.0+
//
// max8997_charger.c - Power supply consumer driver for the Maxim 8997/8966
//
// Copyright (C) 2011 Samsung Electronics
// MyungJoo Ham <myungjoo.ham@samsung.com>
#include <linux/err.h>
#include <linux/extcon.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/mfd/max8997.h>
#include <linux/mfd/max8997-private.h>
#include <linux/regulator/consumer.h>
#include <linux/devm-helpers.h>
/* MAX8997_REG_STATUS4 */
#define DCINOK_SHIFT 1
#define DCINOK_MASK (1 << DCINOK_SHIFT)
#define DETBAT_SHIFT 2
#define DETBAT_MASK (1 << DETBAT_SHIFT)
/* MAX8997_REG_MBCCTRL1 */
#define TFCH_SHIFT 4
#define TFCH_MASK (7 << TFCH_SHIFT)
/* MAX8997_REG_MBCCTRL5 */
#define ITOPOFF_SHIFT 0
#define ITOPOFF_MASK (0xF << ITOPOFF_SHIFT)
struct charger_data {
struct device *dev;
struct max8997_dev *iodev;
struct power_supply *battery;
struct regulator *reg;
struct extcon_dev *edev;
struct notifier_block extcon_nb;
struct work_struct extcon_work;
};
static enum power_supply_property max8997_battery_props[] = {
POWER_SUPPLY_PROP_STATUS, /* "FULL", "CHARGING" or "DISCHARGING". */
POWER_SUPPLY_PROP_PRESENT, /* the presence of battery */
POWER_SUPPLY_PROP_ONLINE, /* charger is active or not */
};
/* Note that the charger control is done by a current regulator "CHARGER" */
static int max8997_battery_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct charger_data *charger = power_supply_get_drvdata(psy);
struct i2c_client *i2c = charger->iodev->i2c;
int ret;
u8 reg;
switch (psp) {
case POWER_SUPPLY_PROP_STATUS:
val->intval = 0;
ret = max8997_read_reg(i2c, MAX8997_REG_STATUS4, &reg);
if (ret)
return ret;
if ((reg & (1 << 0)) == 0x1)
val->intval = POWER_SUPPLY_STATUS_FULL;
else if ((reg & DCINOK_MASK))
val->intval = POWER_SUPPLY_STATUS_CHARGING;
else
val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
break;
case POWER_SUPPLY_PROP_PRESENT:
val->intval = 0;
ret = max8997_read_reg(i2c, MAX8997_REG_STATUS4, &reg);
if (ret)
return ret;
if ((reg & DETBAT_MASK) == 0x0)
val->intval = 1;
break;
case POWER_SUPPLY_PROP_ONLINE:
val->intval = 0;
ret = max8997_read_reg(i2c, MAX8997_REG_STATUS4, &reg);
if (ret)
return ret;
if (reg & DCINOK_MASK)
val->intval = 1;
break;
default:
return -EINVAL;
}
return 0;
}
static void max8997_battery_extcon_evt_worker(struct work_struct *work)
{
struct charger_data *charger =
container_of(work, struct charger_data, extcon_work);
struct extcon_dev *edev = charger->edev;
int current_limit;
if (extcon_get_state(edev, EXTCON_CHG_USB_SDP) > 0) {
dev_dbg(charger->dev, "USB SDP charger is connected\n");
current_limit = 450000;
} else if (extcon_get_state(edev, EXTCON_CHG_USB_DCP) > 0) {
dev_dbg(charger->dev, "USB DCP charger is connected\n");
current_limit = 650000;
} else if (extcon_get_state(edev, EXTCON_CHG_USB_FAST) > 0) {
dev_dbg(charger->dev, "USB FAST charger is connected\n");
current_limit = 650000;
} else if (extcon_get_state(edev, EXTCON_CHG_USB_SLOW) > 0) {
dev_dbg(charger->dev, "USB SLOW charger is connected\n");
current_limit = 650000;
} else if (extcon_get_state(edev, EXTCON_CHG_USB_CDP) > 0) {
dev_dbg(charger->dev, "USB CDP charger is connected\n");
current_limit = 650000;
} else {
dev_dbg(charger->dev, "USB charger is disconnected\n");
current_limit = -1;
}
if (current_limit > 0) {
int ret = regulator_set_current_limit(charger->reg, current_limit, current_limit);
if (ret) {
dev_err(charger->dev, "failed to set current limit: %d\n", ret);
return;
}
ret = regulator_enable(charger->reg);
if (ret)
dev_err(charger->dev, "failed to enable regulator: %d\n", ret);
} else {
int ret = regulator_disable(charger->reg);
if (ret)
dev_err(charger->dev, "failed to disable regulator: %d\n", ret);
}
}
static int max8997_battery_extcon_evt(struct notifier_block *nb,
unsigned long event, void *param)
{
struct charger_data *charger =
container_of(nb, struct charger_data, extcon_nb);
schedule_work(&charger->extcon_work);
return NOTIFY_OK;
}
static const struct power_supply_desc max8997_battery_desc = {
.name = "max8997_pmic",
.type = POWER_SUPPLY_TYPE_BATTERY,
.get_property = max8997_battery_get_property,
.properties = max8997_battery_props,
.num_properties = ARRAY_SIZE(max8997_battery_props),
};
static int max8997_battery_probe(struct platform_device *pdev)
{
int ret = 0;
struct charger_data *charger;
struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);
struct device_node *np = pdev->dev.of_node;
struct i2c_client *i2c = iodev->i2c;
struct max8997_platform_data *pdata = iodev->pdata;
struct power_supply_config psy_cfg = {};
if (!pdata) {
dev_err(&pdev->dev, "No platform data supplied.\n");
return -EINVAL;
}
if (pdata->eoc_mA) {
int val = (pdata->eoc_mA - 50) / 10;
if (val < 0)
val = 0;
if (val > 0xf)
val = 0xf;
ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL5,
val << ITOPOFF_SHIFT, ITOPOFF_MASK);
if (ret < 0) {
dev_err(&pdev->dev, "Cannot use i2c bus.\n");
return ret;
}
}
switch (pdata->timeout) {
case 5:
ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
0x2 << TFCH_SHIFT, TFCH_MASK);
break;
case 6:
ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
0x3 << TFCH_SHIFT, TFCH_MASK);
break;
case 7:
ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
0x4 << TFCH_SHIFT, TFCH_MASK);
break;
case 0:
ret = max8997_update_reg(i2c, MAX8997_REG_MBCCTRL1,
0x7 << TFCH_SHIFT, TFCH_MASK);
break;
default:
dev_err(&pdev->dev, "incorrect timeout value (%d)\n",
pdata->timeout);
return -EINVAL;
}
if (ret < 0) {
dev_err(&pdev->dev, "Cannot use i2c bus.\n");
return ret;
}
charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
if (!charger)
return -ENOMEM;
platform_set_drvdata(pdev, charger);
charger->dev = &pdev->dev;
charger->iodev = iodev;
psy_cfg.drv_data = charger;
charger->battery = devm_power_supply_register(&pdev->dev,
&max8997_battery_desc,
&psy_cfg);
if (IS_ERR(charger->battery)) {
dev_err(&pdev->dev, "failed: power supply register\n");
return PTR_ERR(charger->battery);
}
// grab regulator from parent device's node
pdev->dev.of_node = iodev->dev->of_node;
charger->reg = devm_regulator_get_optional(&pdev->dev, "charger");
pdev->dev.of_node = np;
if (IS_ERR(charger->reg)) {
if (PTR_ERR(charger->reg) == -EPROBE_DEFER)
return -EPROBE_DEFER;
dev_info(&pdev->dev, "couldn't get charger regulator\n");
}
charger->edev = extcon_get_extcon_dev("max8997-muic");
if (IS_ERR(charger->edev)) {
dev_err_probe(charger->dev, PTR_ERR(charger->edev),
"couldn't get extcon device: max8997-muic\n");
return PTR_ERR(charger->edev);
}
if (!IS_ERR(charger->reg) && !IS_ERR_OR_NULL(charger->edev)) {
ret = devm_work_autocancel(&pdev->dev, &charger->extcon_work,
max8997_battery_extcon_evt_worker);
if (ret) {
dev_err(&pdev->dev, "failed to add extcon evt stop action: %d\n", ret);
return ret;
}
charger->extcon_nb.notifier_call = max8997_battery_extcon_evt;
ret = devm_extcon_register_notifier_all(&pdev->dev, charger->edev,
&charger->extcon_nb);
if (ret) {
dev_err(&pdev->dev, "failed to register extcon notifier\n");
return ret;
}
}
return 0;
}
static const struct platform_device_id max8997_battery_id[] = {
{ "max8997-battery", 0 },
{ }
};
MODULE_DEVICE_TABLE(platform, max8997_battery_id);
static struct platform_driver max8997_battery_driver = {
.driver = {
.name = "max8997-battery",
},
.probe = max8997_battery_probe,
.id_table = max8997_battery_id,
};
module_platform_driver(max8997_battery_driver);
MODULE_DESCRIPTION("MAXIM 8997/8966 battery control driver");
MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_LICENSE("GPL");
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