[linux.git] / drivers / thermal / kirkwood_thermal.c

/*
 * Kirkwood thermal sensor driver
 *
 * Copyright (C) 2012 Nobuhiro Iwamatsu <[email protected]>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 */
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/thermal.h>

#define KIRKWOOD_THERMAL_VALID_OFFSET	9
#define KIRKWOOD_THERMAL_VALID_MASK	0x1
#define KIRKWOOD_THERMAL_TEMP_OFFSET	10
#define KIRKWOOD_THERMAL_TEMP_MASK	0x1FF

/* Kirkwood Thermal Sensor Dev Structure */
struct kirkwood_thermal_priv {
	void __iomem *sensor;
};

static int kirkwood_get_temp(struct thermal_zone_device *thermal,
			  int *temp)
{
	unsigned long reg;
	struct kirkwood_thermal_priv *priv = thermal->devdata;

	reg = readl_relaxed(priv->sensor);

	/* Valid check */
	if (!((reg >> KIRKWOOD_THERMAL_VALID_OFFSET) &
	    KIRKWOOD_THERMAL_VALID_MASK)) {
		dev_err(&thermal->device,
			"Temperature sensor reading not valid\n");
		return -EIO;
	}

	/*
	 * Calculate temperature. According to Marvell internal
	 * documentation the formula for this is:
	 * Celsius = (322-reg)/1.3625
	 */
	reg = (reg >> KIRKWOOD_THERMAL_TEMP_OFFSET) &
		KIRKWOOD_THERMAL_TEMP_MASK;
	*temp = ((3220000000UL - (10000000UL * reg)) / 13625);

	return 0;
}

static struct thermal_zone_device_ops ops = {
	.get_temp = kirkwood_get_temp,
};

static const struct of_device_id kirkwood_thermal_id_table[] = {
	{ .compatible = "marvell,kirkwood-thermal" },
	{}
};

static int kirkwood_thermal_probe(struct platform_device *pdev)
{
	struct thermal_zone_device *thermal = NULL;
	struct kirkwood_thermal_priv *priv;
	struct resource *res;

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

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	priv->sensor = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(priv->sensor))
		return PTR_ERR(priv->sensor);

	thermal = thermal_zone_device_register("kirkwood_thermal", 0, 0,
					       priv, &ops, NULL, 0, 0);
	if (IS_ERR(thermal)) {
		dev_err(&pdev->dev,
			"Failed to register thermal zone device\n");
		return PTR_ERR(thermal);
	}

	platform_set_drvdata(pdev, thermal);

	return 0;
}

static int kirkwood_thermal_exit(struct platform_device *pdev)
{
	struct thermal_zone_device *kirkwood_thermal =
		platform_get_drvdata(pdev);

	thermal_zone_device_unregister(kirkwood_thermal);

	return 0;
}

MODULE_DEVICE_TABLE(of, kirkwood_thermal_id_table);

static struct platform_driver kirkwood_thermal_driver = {
	.probe = kirkwood_thermal_probe,
	.remove = kirkwood_thermal_exit,
	.driver = {
		.name = "kirkwood_thermal",
		.of_match_table = kirkwood_thermal_id_table,
	},
};

module_platform_driver(kirkwood_thermal_driver);

MODULE_AUTHOR("Nobuhiro Iwamatsu <[email protected]>");
MODULE_DESCRIPTION("kirkwood thermal driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
7060aa36 NI	1	/*
	2	* Kirkwood thermal sensor driver
	3	*
	4	* Copyright (C) 2012 Nobuhiro Iwamatsu <[email protected]>
	5	*
	6	* This software is licensed under the terms of the GNU General Public
	7	* License version 2, as published by the Free Software Foundation, and
	8	* may be copied, distributed, and modified under those terms.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	*/
	16	#include <linux/device.h>
	17	#include <linux/err.h>
	18	#include <linux/io.h>
	19	#include <linux/kernel.h>
	20	#include <linux/of.h>
	21	#include <linux/module.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/thermal.h>
	24
	25	#define KIRKWOOD_THERMAL_VALID_OFFSET 9
	26	#define KIRKWOOD_THERMAL_VALID_MASK 0x1
	27	#define KIRKWOOD_THERMAL_TEMP_OFFSET 10
	28	#define KIRKWOOD_THERMAL_TEMP_MASK 0x1FF
	29
	30	/* Kirkwood Thermal Sensor Dev Structure */
	31	struct kirkwood_thermal_priv {
	32	void __iomem *sensor;
	33	};
	34
	35	static int kirkwood_get_temp(struct thermal_zone_device *thermal,
17e8351a	36	int *temp)
7060aa36 NI	37	{
	38	unsigned long reg;
	39	struct kirkwood_thermal_priv *priv = thermal->devdata;
	40
	41	reg = readl_relaxed(priv->sensor);
	42
	43	/* Valid check */
02519d33 EG	44	if (!((reg >> KIRKWOOD_THERMAL_VALID_OFFSET) &
02519d33 EG	45	KIRKWOOD_THERMAL_VALID_MASK)) {
7060aa36 NI	46	dev_err(&thermal->device,
	47	"Temperature sensor reading not valid\n");
	48	return -EIO;
	49	}
	50
	51	/*
696b6075 EG	52	* Calculate temperature. According to Marvell internal
	53	* documentation the formula for this is:
	54	* Celsius = (322-reg)/1.3625
7060aa36 NI	55	*/
	56	reg = (reg >> KIRKWOOD_THERMAL_TEMP_OFFSET) &
	57	KIRKWOOD_THERMAL_TEMP_MASK;
696b6075	58	temp = ((3220000000UL - (10000000UL reg)) / 13625);
7060aa36 NI	59
	60	return 0;
	61	}
	62
	63	static struct thermal_zone_device_ops ops = {
	64	.get_temp = kirkwood_get_temp,
	65	};
	66
	67	static const struct of_device_id kirkwood_thermal_id_table[] = {
	68	{ .compatible = "marvell,kirkwood-thermal" },
	69	{}
	70	};
	71
	72	static int kirkwood_thermal_probe(struct platform_device *pdev)
	73	{
	74	struct thermal_zone_device *thermal = NULL;
	75	struct kirkwood_thermal_priv *priv;
	76	struct resource *res;
	77
7060aa36 NI	78	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	79	if (!priv)
	80	return -ENOMEM;
	81
c28f692c	82	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
aa3b5d22 SK	83	priv->sensor = devm_ioremap_resource(&pdev->dev, res);
	84	if (IS_ERR(priv->sensor))
	85	return PTR_ERR(priv->sensor);
7060aa36 NI	86
	87	thermal = thermal_zone_device_register("kirkwood_thermal", 0, 0,
	88	priv, &ops, NULL, 0, 0);
	89	if (IS_ERR(thermal)) {
	90	dev_err(&pdev->dev,
	91	"Failed to register thermal zone device\n");
	92	return PTR_ERR(thermal);
	93	}
	94
	95	platform_set_drvdata(pdev, thermal);
	96
	97	return 0;
	98	}
	99
	100	static int kirkwood_thermal_exit(struct platform_device *pdev)
	101	{
	102	struct thermal_zone_device *kirkwood_thermal =
	103	platform_get_drvdata(pdev);
	104
	105	thermal_zone_device_unregister(kirkwood_thermal);
7060aa36 NI	106
	107	return 0;
	108	}
	109
	110	MODULE_DEVICE_TABLE(of, kirkwood_thermal_id_table);
	111
	112	static struct platform_driver kirkwood_thermal_driver = {
	113	.probe = kirkwood_thermal_probe,
	114	.remove = kirkwood_thermal_exit,
	115	.driver = {
	116	.name = "kirkwood_thermal",
90c3194e	117	.of_match_table = kirkwood_thermal_id_table,
7060aa36 NI	118	},
	119	};
	120
	121	module_platform_driver(kirkwood_thermal_driver);
	122
	123	MODULE_AUTHOR("Nobuhiro Iwamatsu <[email protected]>");
	124	MODULE_DESCRIPTION("kirkwood thermal driver");
	125	MODULE_LICENSE("GPL");