hwmon: (abx500) Decomission abx500 driver

This deletes the ABx500 hwmon driver, the only supported
variant being the AB8500.

This driver has been replaced by generic frameworks. By
inspecting the abx500 sysfs files we see that it contains
things such as temp1_max, temp1_max_alarm, temp1_max_hyst,
temp1_max_hyst_alarm, temp1_min, temp1_min_alarm.

It becomes obvious that the abx500.c is a reimplementation
of thermal zones. This is not very strange as the generic
thermal zones were not invented when this driver was merged
so people were rolling their own.

The ab8500.c driver contains conversion tables for handling
a thermistor on ADC channels AUX1 and AUX2.

I managed to replace the functionality of the driver with:

- Activation of the ntc_thermistor.c driver,
  CONFIG_SENSORS_NTC_THERMISTOR
- Activation of thermal zones, CONFIG_THERMAL
- In the device tree, connecting the NTC driver to the
  processed IIO channels from the AB8500 GPADC ADC forming
  two instances of NTC sensors.
- Connecting the two NTC sensors to a "chassis" thermal zone
  in the device tree and setting that to hit the CPU frequency
  at 50 degrees celsius and do a critical shutdown at 70
  degrees celsius, deploying a policy using the sensors.

After talking to the original authors we concluded that the
driver was never properly parameterized in production so
what we now have in the device tree is already puts the
thermistors to better use than what the hwmon driver did.

The two remaining channels for two battery temperatures is
already handled in the charging algorithms but can be
optionally extended to thermal zones as well if we want
these to trigger critical shutdown for the platform.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201221125521.768082-1-linus.walleij@linaro.org
[groeck: Removed documentation and fixed up Makefile, Kconfig]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 0 insertions, 487 deletions

diff --git a/drivers/hwmon/abx500.c b/drivers/hwmon/abx500.c
deleted file mode 100644
index 4b9648819836..000000000000
--- a/drivers/hwmon/abx500.c
+++ /dev/null
@@ -1,487 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) ST-Ericsson 2010 - 2013
- * Author: Martin Persson <martin.persson@stericsson.com>
- *         Hongbo Zhang <hongbo.zhang@linaro.org>
- *
- * ABX500 does not provide auto ADC, so to monitor the required temperatures,
- * a periodic work is used. It is more important to not wake up the CPU than
- * to perform this job, hence the use of a deferred delay.
- *
- * A deferred delay for thermal monitor is considered safe because:
- * If the chip gets too hot during a sleep state it's most likely due to
- * external factors, such as the surrounding temperature. I.e. no SW decisions
- * will make any difference.
- */
-
-#include <linux/err.h>
-#include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
-#include <linux/interrupt.h>
-#include <linux/jiffies.h>
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-#include <linux/pm.h>
-#include <linux/slab.h>
-#include <linux/sysfs.h>
-#include <linux/workqueue.h>
-#include "abx500.h"
-
-#define DEFAULT_MONITOR_DELAY	HZ
-#define DEFAULT_MAX_TEMP	130
-
-static inline void schedule_monitor(struct abx500_temp *data)
-{
-	data->work_active = true;
-	schedule_delayed_work(&data->work, DEFAULT_MONITOR_DELAY);
-}
-
-static void threshold_updated(struct abx500_temp *data)
-{
-	int i;
-	for (i = 0; i < data->monitored_sensors; i++)
-		if (data->max[i] != 0 || data->min[i] != 0) {
-			schedule_monitor(data);
-			return;
-		}
-
-	dev_dbg(&data->pdev->dev, "No active thresholds.\n");
-	cancel_delayed_work_sync(&data->work);
-	data->work_active = false;
-}
-
-static void gpadc_monitor(struct work_struct *work)
-{
-	int temp, i, ret;
-	char alarm_node[30];
-	bool updated_min_alarm, updated_max_alarm;
-	struct abx500_temp *data;
-
-	data = container_of(work, struct abx500_temp, work.work);
-	mutex_lock(&data->lock);
-
-	for (i = 0; i < data->monitored_sensors; i++) {
-		/* Thresholds are considered inactive if set to 0 */
-		if (data->max[i] == 0 && data->min[i] == 0)
-			continue;
-
-		if (data->max[i] < data->min[i])
-			continue;
-
-		ret = data->ops.read_sensor(data, data->gpadc_addr[i], &temp);
-		if (ret < 0) {
-			dev_err(&data->pdev->dev, "GPADC read failed\n");
-			continue;
-		}
-
-		updated_min_alarm = false;
-		updated_max_alarm = false;
-
-		if (data->min[i] != 0) {
-			if (temp < data->min[i]) {
-				if (data->min_alarm[i] == false) {
-					data->min_alarm[i] = true;
-					updated_min_alarm = true;
-				}
-			} else {
-				if (data->min_alarm[i] == true) {
-					data->min_alarm[i] = false;
-					updated_min_alarm = true;
-				}
-			}
-		}
-		if (data->max[i] != 0) {
-			if (temp > data->max[i]) {
-				if (data->max_alarm[i] == false) {
-					data->max_alarm[i] = true;
-					updated_max_alarm = true;
-				}
-			} else if (temp < data->max[i] - data->max_hyst[i]) {
-				if (data->max_alarm[i] == true) {
-					data->max_alarm[i] = false;
-					updated_max_alarm = true;
-				}
-			}
-		}
-
-		if (updated_min_alarm) {
-			ret = sprintf(alarm_node, "temp%d_min_alarm", i + 1);
-			sysfs_notify(&data->pdev->dev.kobj, NULL, alarm_node);
-		}
-		if (updated_max_alarm) {
-			ret = sprintf(alarm_node, "temp%d_max_alarm", i + 1);
-			sysfs_notify(&data->pdev->dev.kobj, NULL, alarm_node);
-		}
-	}
-
-	schedule_monitor(data);
-	mutex_unlock(&data->lock);
-}
-
-/* HWMON sysfs interfaces */
-static ssize_t name_show(struct device *dev, struct device_attribute *devattr,
-			 char *buf)
-{
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	/* Show chip name */
-	return data->ops.show_name(dev, devattr, buf);
-}
-
-static ssize_t label_show(struct device *dev,
-			  struct device_attribute *devattr, char *buf)
-{
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	/* Show each sensor label */
-	return data->ops.show_label(dev, devattr, buf);
-}
-
-static ssize_t input_show(struct device *dev,
-			  struct device_attribute *devattr, char *buf)
-{
-	int ret, temp;
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-	u8 gpadc_addr = data->gpadc_addr[attr->index];
-
-	ret = data->ops.read_sensor(data, gpadc_addr, &temp);
-	if (ret < 0)
-		return ret;
-
-	return sprintf(buf, "%d\n", temp);
-}
-
-/* Set functions (RW nodes) */
-static ssize_t min_store(struct device *dev, struct device_attribute *devattr,
-			 const char *buf, size_t count)
-{
-	unsigned long val;
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-	int res = kstrtol(buf, 10, &val);
-	if (res < 0)
-		return res;
-
-	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);
-
-	mutex_lock(&data->lock);
-	data->min[attr->index] = val;
-	threshold_updated(data);
-	mutex_unlock(&data->lock);
-
-	return count;
-}
-
-static ssize_t max_store(struct device *dev, struct device_attribute *devattr,
-			 const char *buf, size_t count)
-{
-	unsigned long val;
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-	int res = kstrtol(buf, 10, &val);
-	if (res < 0)
-		return res;
-
-	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);
-
-	mutex_lock(&data->lock);
-	data->max[attr->index] = val;
-	threshold_updated(data);
-	mutex_unlock(&data->lock);
-
-	return count;
-}
-
-static ssize_t max_hyst_store(struct device *dev,
-			      struct device_attribute *devattr,
-			      const char *buf, size_t count)
-{
-	unsigned long val;
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-	int res = kstrtoul(buf, 10, &val);
-	if (res < 0)
-		return res;
-
-	val = clamp_val(val, 0, DEFAULT_MAX_TEMP);
-
-	mutex_lock(&data->lock);
-	data->max_hyst[attr->index] = val;
-	threshold_updated(data);
-	mutex_unlock(&data->lock);
-
-	return count;
-}
-
-/* Show functions (RO nodes) */
-static ssize_t min_show(struct device *dev, struct device_attribute *devattr,
-			char *buf)
-{
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-
-	return sprintf(buf, "%lu\n", data->min[attr->index]);
-}
-
-static ssize_t max_show(struct device *dev, struct device_attribute *devattr,
-			char *buf)
-{
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-
-	return sprintf(buf, "%lu\n", data->max[attr->index]);
-}
-
-static ssize_t max_hyst_show(struct device *dev,
-			     struct device_attribute *devattr, char *buf)
-{
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-
-	return sprintf(buf, "%lu\n", data->max_hyst[attr->index]);
-}
-
-static ssize_t min_alarm_show(struct device *dev,
-			      struct device_attribute *devattr, char *buf)
-{
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-
-	return sprintf(buf, "%d\n", data->min_alarm[attr->index]);
-}
-
-static ssize_t max_alarm_show(struct device *dev,
-			      struct device_attribute *devattr, char *buf)
-{
-	struct abx500_temp *data = dev_get_drvdata(dev);
-	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
-
-	return sprintf(buf, "%d\n", data->max_alarm[attr->index]);
-}
-
-static umode_t abx500_attrs_visible(struct kobject *kobj,
-				   struct attribute *attr, int n)
-{
-	struct device *dev = kobj_to_dev(kobj);
-	struct abx500_temp *data = dev_get_drvdata(dev);
-
-	if (data->ops.is_visible)
-		return data->ops.is_visible(attr, n);
-
-	return attr->mode;
-}
-
-/* Chip name, required by hwmon */
-static SENSOR_DEVICE_ATTR_RO(name, name, 0);
-
-/* GPADC - SENSOR1 */
-static SENSOR_DEVICE_ATTR_RO(temp1_label, label, 0);
-static SENSOR_DEVICE_ATTR_RO(temp1_input, input, 0);
-static SENSOR_DEVICE_ATTR_RW(temp1_min, min, 0);
-static SENSOR_DEVICE_ATTR_RW(temp1_max, max, 0);
-static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, max_hyst, 0);
-static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, min_alarm, 0);
-static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, max_alarm, 0);
-
-/* GPADC - SENSOR2 */
-static SENSOR_DEVICE_ATTR_RO(temp2_label, label, 1);
-static SENSOR_DEVICE_ATTR_RO(temp2_input, input, 1);
-static SENSOR_DEVICE_ATTR_RW(temp2_min, min, 1);
-static SENSOR_DEVICE_ATTR_RW(temp2_max, max, 1);
-static SENSOR_DEVICE_ATTR_RW(temp2_max_hyst, max_hyst, 1);
-static SENSOR_DEVICE_ATTR_RO(temp2_min_alarm, min_alarm, 1);
-static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, max_alarm, 1);
-
-/* GPADC - SENSOR3 */
-static SENSOR_DEVICE_ATTR_RO(temp3_label, label, 2);
-static SENSOR_DEVICE_ATTR_RO(temp3_input, input, 2);
-static SENSOR_DEVICE_ATTR_RW(temp3_min, min, 2);
-static SENSOR_DEVICE_ATTR_RW(temp3_max, max, 2);
-static SENSOR_DEVICE_ATTR_RW(temp3_max_hyst, max_hyst, 2);
-static SENSOR_DEVICE_ATTR_RO(temp3_min_alarm, min_alarm, 2);
-static SENSOR_DEVICE_ATTR_RO(temp3_max_alarm, max_alarm, 2);
-
-/* GPADC - SENSOR4 */
-static SENSOR_DEVICE_ATTR_RO(temp4_label, label, 3);
-static SENSOR_DEVICE_ATTR_RO(temp4_input, input, 3);
-static SENSOR_DEVICE_ATTR_RW(temp4_min, min, 3);
-static SENSOR_DEVICE_ATTR_RW(temp4_max, max, 3);
-static SENSOR_DEVICE_ATTR_RW(temp4_max_hyst, max_hyst, 3);
-static SENSOR_DEVICE_ATTR_RO(temp4_min_alarm, min_alarm, 3);
-static SENSOR_DEVICE_ATTR_RO(temp4_max_alarm, max_alarm, 3);
-
-static struct attribute *abx500_temp_attributes[] = {
-	&sensor_dev_attr_name.dev_attr.attr,
-
-	&sensor_dev_attr_temp1_label.dev_attr.attr,
-	&sensor_dev_attr_temp1_input.dev_attr.attr,
-	&sensor_dev_attr_temp1_min.dev_attr.attr,
-	&sensor_dev_attr_temp1_max.dev_attr.attr,
-	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
-	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
-
-	&sensor_dev_attr_temp2_label.dev_attr.attr,
-	&sensor_dev_attr_temp2_input.dev_attr.attr,
-	&sensor_dev_attr_temp2_min.dev_attr.attr,
-	&sensor_dev_attr_temp2_max.dev_attr.attr,
-	&sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
-	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
-
-	&sensor_dev_attr_temp3_label.dev_attr.attr,
-	&sensor_dev_attr_temp3_input.dev_attr.attr,
-	&sensor_dev_attr_temp3_min.dev_attr.attr,
-	&sensor_dev_attr_temp3_max.dev_attr.attr,
-	&sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
-	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
-
-	&sensor_dev_attr_temp4_label.dev_attr.attr,
-	&sensor_dev_attr_temp4_input.dev_attr.attr,
-	&sensor_dev_attr_temp4_min.dev_attr.attr,
-	&sensor_dev_attr_temp4_max.dev_attr.attr,
-	&sensor_dev_attr_temp4_max_hyst.dev_attr.attr,
-	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
-	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
-	NULL
-};
-
-static const struct attribute_group abx500_temp_group = {
-	.attrs = abx500_temp_attributes,
-	.is_visible = abx500_attrs_visible,
-};
-
-static irqreturn_t abx500_temp_irq_handler(int irq, void *irq_data)
-{
-	struct platform_device *pdev = irq_data;
-	struct abx500_temp *data = platform_get_drvdata(pdev);
-
-	data->ops.irq_handler(irq, data);
-	return IRQ_HANDLED;
-}
-
-static int setup_irqs(struct platform_device *pdev)
-{
-	int ret;
-	int irq = platform_get_irq_byname(pdev, "ABX500_TEMP_WARM");
-
-	if (irq < 0) {
-		dev_err(&pdev->dev, "Get irq by name failed\n");
-		return irq;
-	}
-
-	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
-		abx500_temp_irq_handler, 0, "abx500-temp", pdev);
-	if (ret < 0)
-		dev_err(&pdev->dev, "Request threaded irq failed (%d)\n", ret);
-
-	return ret;
-}
-
-static int abx500_temp_probe(struct platform_device *pdev)
-{
-	struct abx500_temp *data;
-	int err;
-
-	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
-	data->pdev = pdev;
-	mutex_init(&data->lock);
-
-	/* Chip specific initialization */
-	err = abx500_hwmon_init(data);
-	if (err	< 0 || !data->ops.read_sensor || !data->ops.show_name ||
-			!data->ops.show_label)
-		return err;
-
-	INIT_DEFERRABLE_WORK(&data->work, gpadc_monitor);
-
-	platform_set_drvdata(pdev, data);
-
-	err = sysfs_create_group(&pdev->dev.kobj, &abx500_temp_group);
-	if (err < 0) {
-		dev_err(&pdev->dev, "Create sysfs group failed (%d)\n", err);
-		return err;
-	}
-
-	data->hwmon_dev = hwmon_device_register(&pdev->dev);
-	if (IS_ERR(data->hwmon_dev)) {
-		err = PTR_ERR(data->hwmon_dev);
-		dev_err(&pdev->dev, "Class registration failed (%d)\n", err);
-		goto exit_sysfs_group;
-	}
-
-	if (data->ops.irq_handler) {
-		err = setup_irqs(pdev);
-		if (err < 0)
-			goto exit_hwmon_reg;
-	}
-	return 0;
-
-exit_hwmon_reg:
-	hwmon_device_unregister(data->hwmon_dev);
-exit_sysfs_group:
-	sysfs_remove_group(&pdev->dev.kobj, &abx500_temp_group);
-	return err;
-}
-
-static int abx500_temp_remove(struct platform_device *pdev)
-{
-	struct abx500_temp *data = platform_get_drvdata(pdev);
-
-	cancel_delayed_work_sync(&data->work);
-	hwmon_device_unregister(data->hwmon_dev);
-	sysfs_remove_group(&pdev->dev.kobj, &abx500_temp_group);
-
-	return 0;
-}
-
-static int abx500_temp_suspend(struct platform_device *pdev,
-			       pm_message_t state)
-{
-	struct abx500_temp *data = platform_get_drvdata(pdev);
-
-	if (data->work_active)
-		cancel_delayed_work_sync(&data->work);
-
-	return 0;
-}
-
-static int abx500_temp_resume(struct platform_device *pdev)
-{
-	struct abx500_temp *data = platform_get_drvdata(pdev);
-
-	if (data->work_active)
-		schedule_monitor(data);
-
-	return 0;
-}
-
-#ifdef CONFIG_OF
-static const struct of_device_id abx500_temp_match[] = {
-	{ .compatible = "stericsson,abx500-temp" },
-	{},
-};
-MODULE_DEVICE_TABLE(of, abx500_temp_match);
-#endif
-
-static struct platform_driver abx500_temp_driver = {
-	.driver = {
-		.name = "abx500-temp",
-		.of_match_table = of_match_ptr(abx500_temp_match),
-	},
-	.suspend = abx500_temp_suspend,
-	.resume = abx500_temp_resume,
-	.probe = abx500_temp_probe,
-	.remove = abx500_temp_remove,
-};
-
-module_platform_driver(abx500_temp_driver);
-
-MODULE_AUTHOR("Martin Persson <martin.persson@stericsson.com>");
-MODULE_DESCRIPTION("ABX500 temperature driver");
-MODULE_LICENSE("GPL");