Merge commit 'main-jb-2012.08.03-B4' into t114-0806
[linux-2.6.git] / drivers / hwmon / jz4740-hwmon.c
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
29 struct 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
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;
62         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
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
104 static 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
173 err_remove_file:
174         sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
175 err_free_irq:
176         free_irq(hwmon->irq, hwmon);
177 err_iounmap:
178         platform_set_drvdata(pdev, NULL);
179         iounmap(hwmon->base);
180 err_release_mem_region:
181         release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));
182 err_free:
183         kfree(hwmon);
184
185         return ret;
186 }
187
188 static 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
206 static struct 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
215 module_platform_driver(jz4740_hwmon_driver);
216
217 MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
218 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
219 MODULE_LICENSE("GPL");
220 MODULE_ALIAS("platform:jz4740-hwmon");