Linux Kernel  3.7.1
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dma-sysfs.c
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1 /*
2  * arch/sh/drivers/dma/dma-sysfs.c
3  *
4  * sysfs interface for SH DMA API
5  *
6  * Copyright (C) 2004 - 2006 Paul Mundt
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License. See the file "COPYING" in the main directory of this archive
10  * for more details.
11  */
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/stat.h>
15 #include <linux/device.h>
16 #include <linux/platform_device.h>
17 #include <linux/err.h>
18 #include <linux/string.h>
19 #include <asm/dma.h>
20 
21 static struct bus_type dma_subsys = {
22  .name = "dma",
23  .dev_name = "dma",
24 };
25 
26 static ssize_t dma_show_devices(struct device *dev,
27  struct device_attribute *attr, char *buf)
28 {
29  ssize_t len = 0;
30  int i;
31 
32  for (i = 0; i < 16; i++) {
33  struct dma_info *info = get_dma_info(i);
34  struct dma_channel *channel = get_dma_channel(i);
35 
36  if (unlikely(!info) || !channel)
37  continue;
38 
39  len += sprintf(buf + len, "%2d: %14s %s\n",
40  channel->chan, info->name,
41  channel->dev_id);
42  }
43 
44  return len;
45 }
46 
47 static DEVICE_ATTR(devices, S_IRUGO, dma_show_devices, NULL);
48 
49 static int __init dma_subsys_init(void)
50 {
51  int ret;
52 
53  ret = subsys_system_register(&dma_subsys, NULL);
54  if (unlikely(ret))
55  return ret;
56 
57  return device_create_file(dma_subsys.dev_root, &dev_attr_devices);
58 }
59 postcore_initcall(dma_subsys_init);
60 
61 static ssize_t dma_show_dev_id(struct device *dev,
62  struct device_attribute *attr, char *buf)
63 {
64  struct dma_channel *channel = to_dma_channel(dev);
65  return sprintf(buf, "%s\n", channel->dev_id);
66 }
67 
68 static ssize_t dma_store_dev_id(struct device *dev,
69  struct device_attribute *attr,
70  const char *buf, size_t count)
71 {
72  struct dma_channel *channel = to_dma_channel(dev);
73  strcpy(channel->dev_id, buf);
74  return count;
75 }
76 
77 static DEVICE_ATTR(dev_id, S_IRUGO | S_IWUSR, dma_show_dev_id, dma_store_dev_id);
78 
79 static ssize_t dma_store_config(struct device *dev,
80  struct device_attribute *attr,
81  const char *buf, size_t count)
82 {
83  struct dma_channel *channel = to_dma_channel(dev);
84  unsigned long config;
85 
86  config = simple_strtoul(buf, NULL, 0);
87  dma_configure_channel(channel->vchan, config);
88 
89  return count;
90 }
91 
92 static DEVICE_ATTR(config, S_IWUSR, NULL, dma_store_config);
93 
94 static ssize_t dma_show_mode(struct device *dev,
95  struct device_attribute *attr, char *buf)
96 {
97  struct dma_channel *channel = to_dma_channel(dev);
98  return sprintf(buf, "0x%08x\n", channel->mode);
99 }
100 
101 static ssize_t dma_store_mode(struct device *dev,
102  struct device_attribute *attr,
103  const char *buf, size_t count)
104 {
105  struct dma_channel *channel = to_dma_channel(dev);
106  channel->mode = simple_strtoul(buf, NULL, 0);
107  return count;
108 }
109 
110 static DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, dma_show_mode, dma_store_mode);
111 
112 #define dma_ro_attr(field, fmt) \
113 static ssize_t dma_show_##field(struct device *dev, \
114  struct device_attribute *attr, char *buf)\
115 { \
116  struct dma_channel *channel = to_dma_channel(dev); \
117  return sprintf(buf, fmt, channel->field); \
118 } \
119 static DEVICE_ATTR(field, S_IRUGO, dma_show_##field, NULL);
120 
121 dma_ro_attr(count, "0x%08x\n");
122 dma_ro_attr(flags, "0x%08lx\n");
123 
125 {
126  struct device *dev = &chan->dev;
127  char name[16];
128  int ret;
129 
130  dev->id = chan->vchan;
131  dev->bus = &dma_subsys;
132 
133  ret = device_register(dev);
134  if (ret)
135  return ret;
136 
137  ret |= device_create_file(dev, &dev_attr_dev_id);
138  ret |= device_create_file(dev, &dev_attr_count);
139  ret |= device_create_file(dev, &dev_attr_mode);
140  ret |= device_create_file(dev, &dev_attr_flags);
141  ret |= device_create_file(dev, &dev_attr_config);
142 
143  if (unlikely(ret)) {
144  dev_err(&info->pdev->dev, "Failed creating attrs\n");
145  return ret;
146  }
147 
148  snprintf(name, sizeof(name), "dma%d", chan->chan);
149  return sysfs_create_link(&info->pdev->dev.kobj, &dev->kobj, name);
150 }
151 
152 void dma_remove_sysfs_files(struct dma_channel *chan, struct dma_info *info)
153 {
154  struct device *dev = &chan->dev;
155  char name[16];
156 
157  device_remove_file(dev, &dev_attr_dev_id);
158  device_remove_file(dev, &dev_attr_count);
159  device_remove_file(dev, &dev_attr_mode);
160  device_remove_file(dev, &dev_attr_flags);
161  device_remove_file(dev, &dev_attr_config);
162 
163  snprintf(name, sizeof(name), "dma%d", chan->chan);
164  sysfs_remove_link(&info->pdev->dev.kobj, name);
165 
166  device_unregister(dev);
167 }