[linux-2.6-block.git] / drivers / hwmon / jz4740-hwmon.c

/*
 * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
 * JZ4740 SoC HWMON driver
 *
 * This program is free software; you can redistribute it and/or modify it
 * under  the terms of the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the License, or (at your
 * option) any later version.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/io.h>

#include <linux/completion.h>
#include <linux/mfd/core.h>

#include <linux/hwmon.h>

struct jz4740_hwmon {
	void __iomem *base;

	int irq;

	const struct mfd_cell *cell;
	struct device *hwmon;

	struct completion read_completion;

	struct mutex lock;
};

static ssize_t jz4740_hwmon_show_name(struct device *dev,
	struct device_attribute *dev_attr, char *buf)
{
	return sprintf(buf, "jz4740\n");
}

static irqreturn_t jz4740_hwmon_irq(int irq, void *data)
{
	struct jz4740_hwmon *hwmon = data;

	complete(&hwmon->read_completion);
	return IRQ_HANDLED;
}

static ssize_t jz4740_hwmon_read_adcin(struct device *dev,
	struct device_attribute *dev_attr, char *buf)
{
	struct jz4740_hwmon *hwmon = dev_get_drvdata(dev);
	struct completion *completion = &hwmon->read_completion;
	long t;
	unsigned long val;
	int ret;

	mutex_lock(&hwmon->lock);

	reinit_completion(completion);

	enable_irq(hwmon->irq);
	hwmon->cell->enable(to_platform_device(dev));

	t = wait_for_completion_interruptible_timeout(completion, HZ);

	if (t > 0) {
		val = readw(hwmon->base) & 0xfff;
		val = (val * 3300) >> 12;
		ret = sprintf(buf, "%lu\n", val);
	} else {
		ret = t ? t : -ETIMEDOUT;
	}

	hwmon->cell->disable(to_platform_device(dev));
	disable_irq(hwmon->irq);

	mutex_unlock(&hwmon->lock);

	return ret;
}

static DEVICE_ATTR(name, S_IRUGO, jz4740_hwmon_show_name, NULL);
static DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL);

static struct attribute *jz4740_hwmon_attributes[] = {
	&dev_attr_name.attr,
	&dev_attr_in0_input.attr,
	NULL
};

static const struct attribute_group jz4740_hwmon_attr_group = {
	.attrs = jz4740_hwmon_attributes,
};

static int jz4740_hwmon_probe(struct platform_device *pdev)
{
	int ret;
	struct jz4740_hwmon *hwmon;
	struct resource *mem;

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

	hwmon->cell = mfd_get_cell(pdev);

	hwmon->irq = platform_get_irq(pdev, 0);
	if (hwmon->irq < 0) {
		dev_err(&pdev->dev, "Failed to get platform irq: %d\n",
			hwmon->irq);
		return hwmon->irq;
	}

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	hwmon->base = devm_ioremap_resource(&pdev->dev, mem);
	if (IS_ERR(hwmon->base))
		return PTR_ERR(hwmon->base);

	init_completion(&hwmon->read_completion);
	mutex_init(&hwmon->lock);

	platform_set_drvdata(pdev, hwmon);

	ret = devm_request_irq(&pdev->dev, hwmon->irq, jz4740_hwmon_irq, 0,
			       pdev->name, hwmon);
	if (ret) {
		dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
		return ret;
	}
	disable_irq(hwmon->irq);

	ret = sysfs_create_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
	if (ret) {
		dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret);
		return ret;
	}

	hwmon->hwmon = hwmon_device_register(&pdev->dev);
	if (IS_ERR(hwmon->hwmon)) {
		ret = PTR_ERR(hwmon->hwmon);
		goto err_remove_file;
	}

	return 0;

err_remove_file:
	sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
	return ret;
}

static int jz4740_hwmon_remove(struct platform_device *pdev)
{
	struct jz4740_hwmon *hwmon = platform_get_drvdata(pdev);

	hwmon_device_unregister(hwmon->hwmon);
	sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);

	return 0;
}

static struct platform_driver jz4740_hwmon_driver = {
	.probe	= jz4740_hwmon_probe,
	.remove = jz4740_hwmon_remove,
	.driver = {
		.name = "jz4740-hwmon",
	},
};

module_platform_driver(jz4740_hwmon_driver);

MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:jz4740-hwmon");
Commit	Line	Data
7f983ba9 LPC	1	/*
	2	* Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
	3	* JZ4740 SoC HWMON driver
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License as published by the
	7	* Free Software Foundation; either version 2 of the License, or (at your
	8	* option) any later version.
	9	*
	10	* You should have received a copy of the GNU General Public License along
	11	* with this program; if not, write to the Free Software Foundation, Inc.,
	12	* 675 Mass Ave, Cambridge, MA 02139, USA.
	13	*
	14	*/
	15
	16	#include <linux/err.h>
	17	#include <linux/interrupt.h>
	18	#include <linux/kernel.h>
	19	#include <linux/module.h>
	20	#include <linux/mutex.h>
	21	#include <linux/platform_device.h>
	22	#include <linux/slab.h>
b25df2bf	23	#include <linux/io.h>
7f983ba9 LPC	24
	25	#include <linux/completion.h>
	26	#include <linux/mfd/core.h>
	27
	28	#include <linux/hwmon.h>
	29
	30	struct jz4740_hwmon {
7f983ba9 LPC	31	void __iomem *base;
	32
	33	int irq;
	34
e9300066	35	const struct mfd_cell *cell;
7f983ba9 LPC	36	struct device *hwmon;
	37
	38	struct completion read_completion;
	39
	40	struct mutex lock;
	41	};
	42
	43	static ssize_t jz4740_hwmon_show_name(struct device *dev,
	44	struct device_attribute dev_attr, char buf)
	45	{
	46	return sprintf(buf, "jz4740\n");
	47	}
	48
	49	static irqreturn_t jz4740_hwmon_irq(int irq, void *data)
	50	{
	51	struct jz4740_hwmon *hwmon = data;
	52
	53	complete(&hwmon->read_completion);
	54	return IRQ_HANDLED;
	55	}
	56
	57	static ssize_t jz4740_hwmon_read_adcin(struct device *dev,
	58	struct device_attribute dev_attr, char buf)
	59	{
	60	struct jz4740_hwmon *hwmon = dev_get_drvdata(dev);
	61	struct completion *completion = &hwmon->read_completion;
0b57d760	62	long t;
7f983ba9 LPC	63	unsigned long val;
	64	int ret;
	65
	66	mutex_lock(&hwmon->lock);
	67
16735d02	68	reinit_completion(completion);
7f983ba9 LPC	69
	70	enable_irq(hwmon->irq);
	71	hwmon->cell->enable(to_platform_device(dev));
	72
	73	t = wait_for_completion_interruptible_timeout(completion, HZ);
	74
	75	if (t > 0) {
	76	val = readw(hwmon->base) & 0xfff;
	77	val = (val * 3300) >> 12;
	78	ret = sprintf(buf, "%lu\n", val);
	79	} else {
	80	ret = t ? t : -ETIMEDOUT;
	81	}
	82
	83	hwmon->cell->disable(to_platform_device(dev));
	84	disable_irq(hwmon->irq);
	85
	86	mutex_unlock(&hwmon->lock);
	87
	88	return ret;
	89	}
	90
	91	static DEVICE_ATTR(name, S_IRUGO, jz4740_hwmon_show_name, NULL);
	92	static DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL);
	93
	94	static struct attribute *jz4740_hwmon_attributes[] = {
	95	&dev_attr_name.attr,
	96	&dev_attr_in0_input.attr,
	97	NULL
	98	};
	99
	100	static const struct attribute_group jz4740_hwmon_attr_group = {
	101	.attrs = jz4740_hwmon_attributes,
	102	};
	103
6c931ae1	104	static int jz4740_hwmon_probe(struct platform_device *pdev)
7f983ba9 LPC	105	{
	106	int ret;
	107	struct jz4740_hwmon *hwmon;
939a0a3f	108	struct resource *mem;
7f983ba9	109
b25df2bf GR	110	hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
b25df2bf GR	111	if (!hwmon)
7f983ba9	112	return -ENOMEM;
7f983ba9	113
6a54ac21	114	hwmon->cell = mfd_get_cell(pdev);
7f983ba9 LPC	115
	116	hwmon->irq = platform_get_irq(pdev, 0);
	117	if (hwmon->irq < 0) {
b25df2bf GR	118	dev_err(&pdev->dev, "Failed to get platform irq: %d\n",
	119	hwmon->irq);
	120	return hwmon->irq;
7f983ba9 LPC	121	}
7f983ba9 LPC	122
939a0a3f JH	123	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	124	hwmon->base = devm_ioremap_resource(&pdev->dev, mem);
	125	if (IS_ERR(hwmon->base))
	126	return PTR_ERR(hwmon->base);
7f983ba9 LPC	127
	128	init_completion(&hwmon->read_completion);
	129	mutex_init(&hwmon->lock);
	130
	131	platform_set_drvdata(pdev, hwmon);
	132
b25df2bf GR	133	ret = devm_request_irq(&pdev->dev, hwmon->irq, jz4740_hwmon_irq, 0,
b25df2bf GR	134	pdev->name, hwmon);
7f983ba9 LPC	135	if (ret) {
7f983ba9 LPC	136	dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
b25df2bf	137	return ret;
7f983ba9 LPC	138	}
	139	disable_irq(hwmon->irq);
	140
	141	ret = sysfs_create_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
	142	if (ret) {
	143	dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret);
b25df2bf	144	return ret;
7f983ba9 LPC	145	}
	146
	147	hwmon->hwmon = hwmon_device_register(&pdev->dev);
	148	if (IS_ERR(hwmon->hwmon)) {
	149	ret = PTR_ERR(hwmon->hwmon);
	150	goto err_remove_file;
	151	}
	152
	153	return 0;
	154
	155	err_remove_file:
	156	sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
7f983ba9 LPC	157	return ret;
	158	}
	159
281dfd0b	160	static int jz4740_hwmon_remove(struct platform_device *pdev)
7f983ba9 LPC	161	{
	162	struct jz4740_hwmon *hwmon = platform_get_drvdata(pdev);
	163
	164	hwmon_device_unregister(hwmon->hwmon);
	165	sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
	166
7f983ba9 LPC	167	return 0;
	168	}
	169
d6c4f2ac	170	static struct platform_driver jz4740_hwmon_driver = {
7f983ba9	171	.probe = jz4740_hwmon_probe,
9e5e9b7a	172	.remove = jz4740_hwmon_remove,
7f983ba9 LPC	173	.driver = {
7f983ba9 LPC	174	.name = "jz4740-hwmon",
7f983ba9 LPC	175	},
	176	};
	177
25a236a5	178	module_platform_driver(jz4740_hwmon_driver);
7f983ba9 LPC	179
	180	MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
	181	MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
	182	MODULE_LICENSE("GPL");
	183	MODULE_ALIAS("platform:jz4740-hwmon");