// SPDX-License-Identifier: GPL-2.0-only
/*
 * dptf_power:  DPTF platform power driver
 * Copyright (c) 2016, Intel Corporation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/platform_device.h>

/*
 * Presentation of attributes which are defined for INT3407. They are:
 * PMAX : Maximum platform powe
 * PSRC : Platform power source
 * ARTG : Adapter rating
 * CTYP : Charger type
 * PBSS : Battery steady power
 * PROP : Rest of worst case platform Power
 */
#define DPTF_POWER_SHOW(name, object) \
static ssize_t name##_show(struct device *dev,\
			   struct device_attribute *attr,\
			   char *buf)\
{\
	struct acpi_device *acpi_dev = dev_get_drvdata(dev);\
	unsigned long long val;\
	acpi_status status;\
\
	status = acpi_evaluate_integer(acpi_dev->handle, #object,\
				       NULL, &val);\
	if (ACPI_SUCCESS(status))\
		return sprintf(buf, "%d\n", (int)val);\
	else \
		return -EINVAL;\
}

DPTF_POWER_SHOW(max_platform_power_mw, PMAX)
DPTF_POWER_SHOW(platform_power_source, PSRC)
DPTF_POWER_SHOW(adapter_rating_mw, ARTG)
DPTF_POWER_SHOW(battery_steady_power_mw, PBSS)
DPTF_POWER_SHOW(charger_type, CTYP)
DPTF_POWER_SHOW(rest_of_platform_power_mw, PROP)

static DEVICE_ATTR_RO(max_platform_power_mw);
static DEVICE_ATTR_RO(platform_power_source);
static DEVICE_ATTR_RO(adapter_rating_mw);
static DEVICE_ATTR_RO(battery_steady_power_mw);
static DEVICE_ATTR_RO(charger_type);
static DEVICE_ATTR_RO(rest_of_platform_power_mw);

static ssize_t prochot_confirm_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	struct acpi_device *acpi_dev = dev_get_drvdata(dev);
	acpi_status status;
	int seq_no;

	if (kstrtouint(buf, 0, &seq_no) < 0)
		return -EINVAL;

	status = acpi_execute_simple_method(acpi_dev->handle, "PBOK", seq_no);
	if (ACPI_SUCCESS(status))
		return count;

	return -EINVAL;
}

static DEVICE_ATTR_WO(prochot_confirm);

static struct attribute *dptf_power_attrs[] = {
	&dev_attr_max_platform_power_mw.attr,
	&dev_attr_platform_power_source.attr,
	&dev_attr_adapter_rating_mw.attr,
	&dev_attr_battery_steady_power_mw.attr,
	&dev_attr_charger_type.attr,
	&dev_attr_rest_of_platform_power_mw.attr,
	&dev_attr_prochot_confirm.attr,
	NULL
};

static const struct attribute_group dptf_power_attribute_group = {
	.attrs = dptf_power_attrs,
	.name = "dptf_power"
};

#define POWER_STATE_CHANGED		0x81
#define POWER_PROP_CHANGE_EVENT	0x84

static void dptf_power_notify(acpi_handle handle, u32 event, void *data)
{
	struct platform_device *pdev = data;
	char *attr;

	switch (event) {
	case POWER_STATE_CHANGED:
		attr = "platform_power_source";
		break;
	case POWER_PROP_CHANGE_EVENT:
		attr = "rest_of_platform_power_mw";
		break;
	default:
		dev_err(&pdev->dev, "Unsupported event [0x%x]\n", event);
		return;
	}

	/*
	 * Notify that an attribute is changed, so that user space can read
	 * again.
	 */
	sysfs_notify(&pdev->dev.kobj, "dptf_power", attr);
}

static int dptf_power_add(struct platform_device *pdev)
{
	struct acpi_device *acpi_dev;
	acpi_status status;
	unsigned long long ptype;
	int result;

	acpi_dev = ACPI_COMPANION(&(pdev->dev));
	if (!acpi_dev)
		return -ENODEV;

	status = acpi_evaluate_integer(acpi_dev->handle, "PTYP", NULL, &ptype);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	if (ptype != 0x11)
		return -ENODEV;

	result = acpi_install_notify_handler(acpi_dev->handle,
					     ACPI_DEVICE_NOTIFY,
					     dptf_power_notify,
					     (void *)pdev);
	if (result)
		return result;

	result = sysfs_create_group(&pdev->dev.kobj,
				    &dptf_power_attribute_group);
	if (result) {
		acpi_remove_notify_handler(acpi_dev->handle,
					   ACPI_DEVICE_NOTIFY,
					   dptf_power_notify);
		return result;
	}

	platform_set_drvdata(pdev, acpi_dev);

	return 0;
}

static int dptf_power_remove(struct platform_device *pdev)
{
	struct acpi_device *acpi_dev = platform_get_drvdata(pdev);

	acpi_remove_notify_handler(acpi_dev->handle,
				   ACPI_DEVICE_NOTIFY,
				   dptf_power_notify);
	sysfs_remove_group(&pdev->dev.kobj, &dptf_power_attribute_group);

	return 0;
}

static const struct acpi_device_id int3407_device_ids[] = {
	{"INT3407", 0},
	{"INTC1047", 0},
	{"", 0},
};
MODULE_DEVICE_TABLE(acpi, int3407_device_ids);

static struct platform_driver dptf_power_driver = {
	.probe = dptf_power_add,
	.remove = dptf_power_remove,
	.driver = {
		.name = "DPTF Platform Power",
		.acpi_match_table = int3407_device_ids,
	},
};

module_platform_driver(dptf_power_driver);

MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ACPI DPTF platform power driver");