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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 | 31 | void __iomem *base; |
7f983ba9 | 32 | int irq; |
e9300066 | 33 | const struct mfd_cell *cell; |
699f279d | 34 | struct platform_device *pdev; |
7f983ba9 | 35 | struct completion read_completion; |
7f983ba9 LPC |
36 | struct mutex lock; |
37 | }; | |
38 | ||
7f983ba9 LPC |
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 jz4740_hwmon_read_adcin(struct device *dev, | |
48 | struct device_attribute *dev_attr, char *buf) | |
49 | { | |
50 | struct jz4740_hwmon *hwmon = dev_get_drvdata(dev); | |
699f279d | 51 | struct platform_device *pdev = hwmon->pdev; |
7f983ba9 | 52 | struct completion *completion = &hwmon->read_completion; |
0b57d760 | 53 | long t; |
7f983ba9 LPC |
54 | unsigned long val; |
55 | int ret; | |
56 | ||
57 | mutex_lock(&hwmon->lock); | |
58 | ||
16735d02 | 59 | reinit_completion(completion); |
7f983ba9 LPC |
60 | |
61 | enable_irq(hwmon->irq); | |
699f279d | 62 | hwmon->cell->enable(pdev); |
7f983ba9 LPC |
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 | ||
699f279d | 74 | hwmon->cell->disable(pdev); |
7f983ba9 LPC |
75 | disable_irq(hwmon->irq); |
76 | ||
77 | mutex_unlock(&hwmon->lock); | |
78 | ||
79 | return ret; | |
80 | } | |
81 | ||
7f983ba9 LPC |
82 | static DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL); |
83 | ||
699f279d | 84 | static struct attribute *jz4740_attrs[] = { |
7f983ba9 LPC |
85 | &dev_attr_in0_input.attr, |
86 | NULL | |
87 | }; | |
88 | ||
699f279d | 89 | ATTRIBUTE_GROUPS(jz4740); |
7f983ba9 | 90 | |
6c931ae1 | 91 | static int jz4740_hwmon_probe(struct platform_device *pdev) |
7f983ba9 LPC |
92 | { |
93 | int ret; | |
699f279d | 94 | struct device *dev = &pdev->dev; |
7f983ba9 | 95 | struct jz4740_hwmon *hwmon; |
699f279d | 96 | struct device *hwmon_dev; |
939a0a3f | 97 | struct resource *mem; |
7f983ba9 | 98 | |
699f279d | 99 | hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL); |
b25df2bf | 100 | if (!hwmon) |
7f983ba9 | 101 | return -ENOMEM; |
7f983ba9 | 102 | |
6a54ac21 | 103 | hwmon->cell = mfd_get_cell(pdev); |
7f983ba9 LPC |
104 | |
105 | hwmon->irq = platform_get_irq(pdev, 0); | |
106 | if (hwmon->irq < 0) { | |
b25df2bf GR |
107 | dev_err(&pdev->dev, "Failed to get platform irq: %d\n", |
108 | hwmon->irq); | |
109 | return hwmon->irq; | |
7f983ba9 LPC |
110 | } |
111 | ||
939a0a3f JH |
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); | |
7f983ba9 | 116 | |
699f279d | 117 | hwmon->pdev = pdev; |
7f983ba9 LPC |
118 | init_completion(&hwmon->read_completion); |
119 | mutex_init(&hwmon->lock); | |
120 | ||
699f279d | 121 | ret = devm_request_irq(dev, hwmon->irq, jz4740_hwmon_irq, 0, |
b25df2bf | 122 | pdev->name, hwmon); |
7f983ba9 LPC |
123 | if (ret) { |
124 | dev_err(&pdev->dev, "Failed to request irq: %d\n", ret); | |
b25df2bf | 125 | return ret; |
7f983ba9 LPC |
126 | } |
127 | disable_irq(hwmon->irq); | |
128 | ||
699f279d AL |
129 | hwmon_dev = devm_hwmon_device_register_with_groups(dev, "jz4740", hwmon, |
130 | jz4740_groups); | |
131 | return PTR_ERR_OR_ZERO(hwmon_dev); | |
7f983ba9 LPC |
132 | } |
133 | ||
d6c4f2ac | 134 | static struct platform_driver jz4740_hwmon_driver = { |
7f983ba9 | 135 | .probe = jz4740_hwmon_probe, |
7f983ba9 LPC |
136 | .driver = { |
137 | .name = "jz4740-hwmon", | |
7f983ba9 LPC |
138 | }, |
139 | }; | |
140 | ||
25a236a5 | 141 | module_platform_driver(jz4740_hwmon_driver); |
7f983ba9 LPC |
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"); |