tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
23
24#include <linux/completion.h>
25#include <linux/mfd/core.h>
26
27#include <linux/hwmon.h>
28
29struct jz4740_hwmon {
30 struct resource *mem;
31 void __iomem *base;
32
33 int irq;
34
35 const struct mfd_cell *cell;
36 struct device *hwmon;
37
38 struct completion read_completion;
39
40 struct mutex lock;
41};
42
43static 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
49static 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
57static 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;
62 unsigned long t;
63 unsigned long val;
64 int ret;
65
66 mutex_lock(&hwmon->lock);
67
68 INIT_COMPLETION(*completion);
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
91static DEVICE_ATTR(name, S_IRUGO, jz4740_hwmon_show_name, NULL);
92static DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL);
93
94static struct attribute *jz4740_hwmon_attributes[] = {
95 &dev_attr_name.attr,
96 &dev_attr_in0_input.attr,
97 NULL
98};
99
100static const struct attribute_group jz4740_hwmon_attr_group = {
101 .attrs = jz4740_hwmon_attributes,
102};
103
104static int __devinit jz4740_hwmon_probe(struct platform_device *pdev)
105{
106 int ret;
107 struct jz4740_hwmon *hwmon;
108
109 hwmon = kmalloc(sizeof(*hwmon), GFP_KERNEL);
110 if (!hwmon) {
111 dev_err(&pdev->dev, "Failed to allocate driver structure\n");
112 return -ENOMEM;
113 }
114
115 hwmon->cell = mfd_get_cell(pdev);
116
117 hwmon->irq = platform_get_irq(pdev, 0);
118 if (hwmon->irq < 0) {
119 ret = hwmon->irq;
120 dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
121 goto err_free;
122 }
123
124 hwmon->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
125 if (!hwmon->mem) {
126 ret = -ENOENT;
127 dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
128 goto err_free;
129 }
130
131 hwmon->mem = request_mem_region(hwmon->mem->start,
132 resource_size(hwmon->mem), pdev->name);
133 if (!hwmon->mem) {
134 ret = -EBUSY;
135 dev_err(&pdev->dev, "Failed to request mmio memory region\n");
136 goto err_free;
137 }
138
139 hwmon->base = ioremap_nocache(hwmon->mem->start,
140 resource_size(hwmon->mem));
141 if (!hwmon->base) {
142 ret = -EBUSY;
143 dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
144 goto err_release_mem_region;
145 }
146
147 init_completion(&hwmon->read_completion);
148 mutex_init(&hwmon->lock);
149
150 platform_set_drvdata(pdev, hwmon);
151
152 ret = request_irq(hwmon->irq, jz4740_hwmon_irq, 0, pdev->name, hwmon);
153 if (ret) {
154 dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
155 goto err_iounmap;
156 }
157 disable_irq(hwmon->irq);
158
159 ret = sysfs_create_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
160 if (ret) {
161 dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret);
162 goto err_free_irq;
163 }
164
165 hwmon->hwmon = hwmon_device_register(&pdev->dev);
166 if (IS_ERR(hwmon->hwmon)) {
167 ret = PTR_ERR(hwmon->hwmon);
168 goto err_remove_file;
169 }
170
171 return 0;
172
173err_remove_file:
174 sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
175err_free_irq:
176 free_irq(hwmon->irq, hwmon);
177err_iounmap:
178 platform_set_drvdata(pdev, NULL);
179 iounmap(hwmon->base);
180err_release_mem_region:
181 release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));
182err_free:
183 kfree(hwmon);
184
185 return ret;
186}
187
188static int __devexit jz4740_hwmon_remove(struct platform_device *pdev)
189{
190 struct jz4740_hwmon *hwmon = platform_get_drvdata(pdev);
191
192 hwmon_device_unregister(hwmon->hwmon);
193 sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
194
195 free_irq(hwmon->irq, hwmon);
196
197 iounmap(hwmon->base);
198 release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));
199
200 platform_set_drvdata(pdev, NULL);
201 kfree(hwmon);
202
203 return 0;
204}
205
206struct platform_driver jz4740_hwmon_driver = {
207 .probe = jz4740_hwmon_probe,
208 .remove = __devexit_p(jz4740_hwmon_remove),
209 .driver = {
210 .name = "jz4740-hwmon",
211 .owner = THIS_MODULE,
212 },
213};
214
215static int __init jz4740_hwmon_init(void)
216{
217 return platform_driver_register(&jz4740_hwmon_driver);
218}
219module_init(jz4740_hwmon_init);
220
221static void __exit jz4740_hwmon_exit(void)
222{
223 platform_driver_unregister(&jz4740_hwmon_driver);
224}
225module_exit(jz4740_hwmon_exit);
226
227MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
228MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
229MODULE_LICENSE("GPL");
230MODULE_ALIAS("platform:jz4740-hwmon");