summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/jz4740-hwmon.c
blob: 40f106d95afeb582b7dc494634486d52e13168f0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
/*
 * 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/completion.h>
#include <linux/mfd/core.h>

#include <linux/hwmon.h>

struct jz4740_hwmon {
	struct resource *mem;
	void __iomem *base;

	int irq;

	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;
	unsigned long t;
	unsigned long val;
	int ret;

	mutex_lock(&hwmon->lock);

	INIT_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 __devinit jz4740_hwmon_probe(struct platform_device *pdev)
{
	int ret;
	struct jz4740_hwmon *hwmon;

	hwmon = kmalloc(sizeof(*hwmon), GFP_KERNEL);
	if (!hwmon) {
		dev_err(&pdev->dev, "Failed to allocate driver structure\n");
		return -ENOMEM;
	}

	hwmon->cell = mfd_get_cell(pdev);

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

	hwmon->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!hwmon->mem) {
		ret = -ENOENT;
		dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
		goto err_free;
	}

	hwmon->mem = request_mem_region(hwmon->mem->start,
			resource_size(hwmon->mem), pdev->name);
	if (!hwmon->mem) {
		ret = -EBUSY;
		dev_err(&pdev->dev, "Failed to request mmio memory region\n");
		goto err_free;
	}

	hwmon->base = ioremap_nocache(hwmon->mem->start,
			resource_size(hwmon->mem));
	if (!hwmon->base) {
		ret = -EBUSY;
		dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
		goto err_release_mem_region;
	}

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

	platform_set_drvdata(pdev, hwmon);

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

	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);
err_free_irq:
	free_irq(hwmon->irq, hwmon);
err_iounmap:
	platform_set_drvdata(pdev, NULL);
	iounmap(hwmon->base);
err_release_mem_region:
	release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));
err_free:
	kfree(hwmon);

	return ret;
}

static int __devexit 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);

	free_irq(hwmon->irq, hwmon);

	iounmap(hwmon->base);
	release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));

	platform_set_drvdata(pdev, NULL);
	kfree(hwmon);

	return 0;
}

struct platform_driver jz4740_hwmon_driver = {
	.probe	= jz4740_hwmon_probe,
	.remove = __devexit_p(jz4740_hwmon_remove),
	.driver = {
		.name = "jz4740-hwmon",
		.owner = THIS_MODULE,
	},
};

static int __init jz4740_hwmon_init(void)
{
	return platform_driver_register(&jz4740_hwmon_driver);
}
module_init(jz4740_hwmon_init);

static void __exit jz4740_hwmon_exit(void)
{
	platform_driver_unregister(&jz4740_hwmon_driver);
}
module_exit(jz4740_hwmon_exit);

MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:jz4740-hwmon");
OpenPOWER on IntegriCloud