[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / drivers / thermal / thermal-generic-adc.c

/*
 * Generic ADC thermal driver
 *
 * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved.
 *
 * Author: Laxman Dewangan <ldewangan@nvidia.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/iio/consumer.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/thermal.h>

struct gadc_thermal_info {
	struct device *dev;
	struct thermal_zone_device *tz_dev;
	struct iio_channel *channel;
	s32 *lookup_table;
	int nlookup_table;
};

static int gadc_thermal_adc_to_temp(struct gadc_thermal_info *gti, int val)
{
	int temp, temp_hi, temp_lo, adc_hi, adc_lo;
	int i;

	for (i = 0; i < gti->nlookup_table; i++) {
		if (val >= gti->lookup_table[2 * i + 1])
			break;
	}

	if (i == 0) {
		temp = gti->lookup_table[0];
	} else if (i >= gti->nlookup_table) {
		temp = gti->lookup_table[2 * (gti->nlookup_table - 1)];
	} else {
		adc_hi = gti->lookup_table[2 * i - 1];
		adc_lo = gti->lookup_table[2 * i + 1];

		temp_hi = gti->lookup_table[2 * i - 2];
		temp_lo = gti->lookup_table[2 * i];

		temp = temp_hi + mult_frac(temp_lo - temp_hi, val - adc_hi,
					   adc_lo - adc_hi);
	}

	return temp;
}

static int gadc_thermal_get_temp(void *data, int *temp)
{
	struct gadc_thermal_info *gti = data;
	int val;
	int ret;

	ret = iio_read_channel_processed(gti->channel, &val);
	if (ret < 0) {
		dev_err(gti->dev, "IIO channel read failed %d\n", ret);
		return ret;
	}
	*temp = gadc_thermal_adc_to_temp(gti, val);

	return 0;
}

static const struct thermal_zone_of_device_ops gadc_thermal_ops = {
	.get_temp = gadc_thermal_get_temp,
};

static int gadc_thermal_read_linear_lookup_table(struct device *dev,
						 struct gadc_thermal_info *gti)
{
	struct device_node *np = dev->of_node;
	int ntable;
	int ret;

	ntable = of_property_count_elems_of_size(np, "temperature-lookup-table",
						 sizeof(u32));
	if (ntable < 0) {
		dev_err(dev, "Lookup table is not provided\n");
		return ntable;
	}

	if (ntable % 2) {
		dev_err(dev, "Pair of temperature vs ADC read value missing\n");
		return -EINVAL;
	}

	gti->lookup_table = devm_kzalloc(dev, sizeof(*gti->lookup_table) *
					 ntable, GFP_KERNEL);
	if (!gti->lookup_table)
		return -ENOMEM;

	ret = of_property_read_u32_array(np, "temperature-lookup-table",
					 (u32 *)gti->lookup_table, ntable);
	if (ret < 0) {
		dev_err(dev, "Failed to read temperature lookup table: %d\n",
			ret);
		return ret;
	}

	gti->nlookup_table = ntable / 2;

	return 0;
}

static int gadc_thermal_probe(struct platform_device *pdev)
{
	struct gadc_thermal_info *gti;
	int ret;

	if (!pdev->dev.of_node) {
		dev_err(&pdev->dev, "Only DT based supported\n");
		return -ENODEV;
	}

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

	ret = gadc_thermal_read_linear_lookup_table(&pdev->dev, gti);
	if (ret < 0)
		return ret;

	gti->dev = &pdev->dev;
	platform_set_drvdata(pdev, gti);

	gti->channel = iio_channel_get(&pdev->dev, "sensor-channel");
	if (IS_ERR(gti->channel)) {
		ret = PTR_ERR(gti->channel);
		dev_err(&pdev->dev, "IIO channel not found: %d\n", ret);
		return ret;
	}

	gti->tz_dev = thermal_zone_of_sensor_register(&pdev->dev, 0,
						      gti, &gadc_thermal_ops);
	if (IS_ERR(gti->tz_dev)) {
		ret = PTR_ERR(gti->tz_dev);
		dev_err(&pdev->dev, "Thermal zone sensor register failed: %d\n",
			ret);
		goto sensor_fail;
	}

	return 0;

sensor_fail:
	iio_channel_release(gti->channel);

	return ret;
}

static int gadc_thermal_remove(struct platform_device *pdev)
{
	struct gadc_thermal_info *gti = platform_get_drvdata(pdev);

	thermal_zone_of_sensor_unregister(&pdev->dev, gti->tz_dev);
	iio_channel_release(gti->channel);

	return 0;
}

static const struct of_device_id of_adc_thermal_match[] = {
	{ .compatible = "generic-adc-thermal", },
	{},
};
MODULE_DEVICE_TABLE(of, of_adc_thermal_match);

static struct platform_driver gadc_thermal_driver = {
	.driver = {
		.name = "generic-adc-thermal",
		.of_match_table = of_adc_thermal_match,
	},
	.probe = gadc_thermal_probe,
	.remove = gadc_thermal_remove,
};

module_platform_driver(gadc_thermal_driver);

MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_DESCRIPTION("Generic ADC thermal driver using IIO framework with DT");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
b3aef78f LD	1	/*
	2	* Generic ADC thermal driver
	3	*
	4	* Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved.
	5	*
	6	* Author: Laxman Dewangan <ldewangan@nvidia.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12	#include <linux/iio/consumer.h>
	13	#include <linux/kernel.h>
	14	#include <linux/module.h>
	15	#include <linux/platform_device.h>
	16	#include <linux/slab.h>
	17	#include <linux/thermal.h>
	18
	19	struct gadc_thermal_info {
	20	struct device *dev;
	21	struct thermal_zone_device *tz_dev;
	22	struct iio_channel *channel;
	23	s32 *lookup_table;
	24	int nlookup_table;
	25	};
	26
	27	static int gadc_thermal_adc_to_temp(struct gadc_thermal_info *gti, int val)
	28	{
919fc06b	29	int temp, temp_hi, temp_lo, adc_hi, adc_lo;
b3aef78f LD	30	int i;
	31
	32	for (i = 0; i < gti->nlookup_table; i++) {
	33	if (val >= gti->lookup_table[2 * i + 1])
	34	break;
	35	}
	36
	37	if (i == 0) {
	38	temp = gti->lookup_table[0];
919fc06b	39	} else if (i >= gti->nlookup_table) {
b3aef78f LD	40	temp = gti->lookup_table[2 * (gti->nlookup_table - 1)];
	41	} else {
	42	adc_hi = gti->lookup_table[2 * i - 1];
	43	adc_lo = gti->lookup_table[2 * i + 1];
919fc06b BA	44
	45	temp_hi = gti->lookup_table[2 * i - 2];
	46	temp_lo = gti->lookup_table[2 * i];
	47
	48	temp = temp_hi + mult_frac(temp_lo - temp_hi, val - adc_hi,
	49	adc_lo - adc_hi);
b3aef78f LD	50	}
	51
	52	return temp;
	53	}
	54
	55	static int gadc_thermal_get_temp(void data, int temp)
	56	{
	57	struct gadc_thermal_info *gti = data;
	58	int val;
	59	int ret;
	60
	61	ret = iio_read_channel_processed(gti->channel, &val);
	62	if (ret < 0) {
	63	dev_err(gti->dev, "IIO channel read failed %d\n", ret);
	64	return ret;
	65	}
	66	*temp = gadc_thermal_adc_to_temp(gti, val);
	67
	68	return 0;
	69	}
	70
	71	static const struct thermal_zone_of_device_ops gadc_thermal_ops = {
	72	.get_temp = gadc_thermal_get_temp,
	73	};
	74
	75	static int gadc_thermal_read_linear_lookup_table(struct device *dev,
	76	struct gadc_thermal_info *gti)
	77	{
	78	struct device_node *np = dev->of_node;
	79	int ntable;
	80	int ret;
	81
	82	ntable = of_property_count_elems_of_size(np, "temperature-lookup-table",
	83	sizeof(u32));
	84	if (ntable < 0) {
	85	dev_err(dev, "Lookup table is not provided\n");
	86	return ntable;
	87	}
	88
	89	if (ntable % 2) {
	90	dev_err(dev, "Pair of temperature vs ADC read value missing\n");
	91	return -EINVAL;
	92	}
	93
	94	gti->lookup_table = devm_kzalloc(dev, sizeof(gti->lookup_table)
	95	ntable, GFP_KERNEL);
	96	if (!gti->lookup_table)
	97	return -ENOMEM;
	98
	99	ret = of_property_read_u32_array(np, "temperature-lookup-table",
	100	(u32 *)gti->lookup_table, ntable);
	101	if (ret < 0) {
	102	dev_err(dev, "Failed to read temperature lookup table: %d\n",
	103	ret);
	104	return ret;
	105	}
	106
	107	gti->nlookup_table = ntable / 2;
	108
	109	return 0;
	110	}
	111
	112	static int gadc_thermal_probe(struct platform_device *pdev)
	113	{
114	struct gadc_thermal_info *gti;
115	int ret;
116
117	if (!pdev->dev.of_node) {
118	dev_err(&pdev->dev, "Only DT based supported\n");
119	return -ENODEV;
120	}
121
122	gti = devm_kzalloc(&pdev->dev, sizeof(*gti), GFP_KERNEL);
123	if (!gti)
124	return -ENOMEM;
125
126	ret = gadc_thermal_read_linear_lookup_table(&pdev->dev, gti);
127	if (ret < 0)
128	return ret;
129
130	gti->dev = &pdev->dev;
131	platform_set_drvdata(pdev, gti);
132
133	gti->channel = iio_channel_get(&pdev->dev, "sensor-channel");
134	if (IS_ERR(gti->channel)) {
135	ret = PTR_ERR(gti->channel);
136	dev_err(&pdev->dev, "IIO channel not found: %d\n", ret);
137	return ret;
138	}
139
140	gti->tz_dev = thermal_zone_of_sensor_register(&pdev->dev, 0,
141	gti, &gadc_thermal_ops);
142	if (IS_ERR(gti->tz_dev)) {
143	ret = PTR_ERR(gti->tz_dev);
144	dev_err(&pdev->dev, "Thermal zone sensor register failed: %d\n",
145	ret);
146	goto sensor_fail;
147	}
148
149	return 0;
150
151	sensor_fail:
152	iio_channel_release(gti->channel);
153
154	return ret;
155	}
156
157	static int gadc_thermal_remove(struct platform_device *pdev)
158	{
159	struct gadc_thermal_info *gti = platform_get_drvdata(pdev);
160
161	thermal_zone_of_sensor_unregister(&pdev->dev, gti->tz_dev);
162	iio_channel_release(gti->channel);
163
164	return 0;
165	}
166
167	static const struct of_device_id of_adc_thermal_match[] = {
168	{ .compatible = "generic-adc-thermal", },
169	{},
170	};
171	MODULE_DEVICE_TABLE(of, of_adc_thermal_match);
172
173	static struct platform_driver gadc_thermal_driver = {
174	.driver = {
175	.name = "generic-adc-thermal",
176	.of_match_table = of_adc_thermal_match,
177	},
178	.probe = gadc_thermal_probe,
179	.remove = gadc_thermal_remove,
180	};
181
182	module_platform_driver(gadc_thermal_driver);
183
184	MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
185	MODULE_DESCRIPTION("Generic ADC thermal driver using IIO framework with DT");
186	MODULE_LICENSE("GPL v2");