Merge tag 'staging-4.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...
[linux-2.6-microblaze.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 #include <linux/io.h>
24
25 #include <linux/completion.h>
26 #include <linux/mfd/core.h>
27
28 #include <linux/hwmon.h>
29
30 struct jz4740_hwmon {
31         void __iomem *base;
32         int irq;
33         const struct mfd_cell *cell;
34         struct platform_device *pdev;
35         struct completion read_completion;
36         struct mutex lock;
37 };
38
39 static irqreturn_t jz4740_hwmon_irq(int irq, void *data)
40 {
41         struct jz4740_hwmon *hwmon = data;
42
43         complete(&hwmon->read_completion);
44         return IRQ_HANDLED;
45 }
46
47 static ssize_t in0_input_show(struct device *dev,
48                               struct device_attribute *dev_attr, char *buf)
49 {
50         struct jz4740_hwmon *hwmon = dev_get_drvdata(dev);
51         struct platform_device *pdev = hwmon->pdev;
52         struct completion *completion = &hwmon->read_completion;
53         long t;
54         unsigned long val;
55         int ret;
56
57         mutex_lock(&hwmon->lock);
58
59         reinit_completion(completion);
60
61         enable_irq(hwmon->irq);
62         hwmon->cell->enable(pdev);
63
64         t = wait_for_completion_interruptible_timeout(completion, HZ);
65
66         if (t > 0) {
67                 val = readw(hwmon->base) & 0xfff;
68                 val = (val * 3300) >> 12;
69                 ret = sprintf(buf, "%lu\n", val);
70         } else {
71                 ret = t ? t : -ETIMEDOUT;
72         }
73
74         hwmon->cell->disable(pdev);
75         disable_irq(hwmon->irq);
76
77         mutex_unlock(&hwmon->lock);
78
79         return ret;
80 }
81
82 static DEVICE_ATTR_RO(in0_input);
83
84 static struct attribute *jz4740_attrs[] = {
85         &dev_attr_in0_input.attr,
86         NULL
87 };
88
89 ATTRIBUTE_GROUPS(jz4740);
90
91 static int jz4740_hwmon_probe(struct platform_device *pdev)
92 {
93         int ret;
94         struct device *dev = &pdev->dev;
95         struct jz4740_hwmon *hwmon;
96         struct device *hwmon_dev;
97         struct resource *mem;
98
99         hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
100         if (!hwmon)
101                 return -ENOMEM;
102
103         hwmon->cell = mfd_get_cell(pdev);
104
105         hwmon->irq = platform_get_irq(pdev, 0);
106         if (hwmon->irq < 0) {
107                 dev_err(&pdev->dev, "Failed to get platform irq: %d\n",
108                         hwmon->irq);
109                 return hwmon->irq;
110         }
111
112         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
113         hwmon->base = devm_ioremap_resource(&pdev->dev, mem);
114         if (IS_ERR(hwmon->base))
115                 return PTR_ERR(hwmon->base);
116
117         hwmon->pdev = pdev;
118         init_completion(&hwmon->read_completion);
119         mutex_init(&hwmon->lock);
120
121         ret = devm_request_irq(dev, hwmon->irq, jz4740_hwmon_irq, 0,
122                                pdev->name, hwmon);
123         if (ret) {
124                 dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
125                 return ret;
126         }
127         disable_irq(hwmon->irq);
128
129         hwmon_dev = devm_hwmon_device_register_with_groups(dev, "jz4740", hwmon,
130                                                            jz4740_groups);
131         return PTR_ERR_OR_ZERO(hwmon_dev);
132 }
133
134 static struct platform_driver jz4740_hwmon_driver = {
135         .probe  = jz4740_hwmon_probe,
136         .driver = {
137                 .name = "jz4740-hwmon",
138         },
139 };
140
141 module_platform_driver(jz4740_hwmon_driver);
142
143 MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
144 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
145 MODULE_LICENSE("GPL");
146 MODULE_ALIAS("platform:jz4740-hwmon");