Version:  2.0.40 2.2.26 2.4.37 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17

Linux/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 
 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         reinit_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 jz4740_hwmon_probe(struct platform_device *pdev)
105 {
106         int ret;
107         struct jz4740_hwmon *hwmon;
108         struct resource *mem;
109 
110         hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
111         if (!hwmon)
112                 return -ENOMEM;
113 
114         hwmon->cell = mfd_get_cell(pdev);
115 
116         hwmon->irq = platform_get_irq(pdev, 0);
117         if (hwmon->irq < 0) {
118                 dev_err(&pdev->dev, "Failed to get platform irq: %d\n",
119                         hwmon->irq);
120                 return hwmon->irq;
121         }
122 
123         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
124         hwmon->base = devm_ioremap_resource(&pdev->dev, mem);
125         if (IS_ERR(hwmon->base))
126                 return PTR_ERR(hwmon->base);
127 
128         init_completion(&hwmon->read_completion);
129         mutex_init(&hwmon->lock);
130 
131         platform_set_drvdata(pdev, hwmon);
132 
133         ret = devm_request_irq(&pdev->dev, hwmon->irq, jz4740_hwmon_irq, 0,
134                                pdev->name, hwmon);
135         if (ret) {
136                 dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
137                 return ret;
138         }
139         disable_irq(hwmon->irq);
140 
141         ret = sysfs_create_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
142         if (ret) {
143                 dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret);
144                 return ret;
145         }
146 
147         hwmon->hwmon = hwmon_device_register(&pdev->dev);
148         if (IS_ERR(hwmon->hwmon)) {
149                 ret = PTR_ERR(hwmon->hwmon);
150                 goto err_remove_file;
151         }
152 
153         return 0;
154 
155 err_remove_file:
156         sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
157         return ret;
158 }
159 
160 static int jz4740_hwmon_remove(struct platform_device *pdev)
161 {
162         struct jz4740_hwmon *hwmon = platform_get_drvdata(pdev);
163 
164         hwmon_device_unregister(hwmon->hwmon);
165         sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
166 
167         return 0;
168 }
169 
170 static struct platform_driver jz4740_hwmon_driver = {
171         .probe  = jz4740_hwmon_probe,
172         .remove = jz4740_hwmon_remove,
173         .driver = {
174                 .name = "jz4740-hwmon",
175                 .owner = THIS_MODULE,
176         },
177 };
178 
179 module_platform_driver(jz4740_hwmon_driver);
180 
181 MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
182 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
183 MODULE_LICENSE("GPL");
184 MODULE_ALIAS("platform:jz4740-hwmon");
185 

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