arch/sh/drivers/dma/dma-sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * arch/sh/drivers/dma/dma-sysfs.c
   4  *
   5  * sysfs interface for SH DMA API
   6  *
   7  * Copyright (C) 2004 - 2006  Paul Mundt
   8  */
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/stat.h>
  12 #include <linux/device.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/err.h>
  15 #include <linux/string.h>
  16 #include <asm/dma.h>
  17
  18 static const struct bus_type dma_subsys = {
  19         .name = "dma",
  20         .dev_name = "dma",
  21 };
  22
  23 static ssize_t dma_show_devices(struct device *dev,
  24                                 struct device_attribute *attr, char *buf)
  25 {
  26         ssize_t len = 0;
  27         int i;
  28
  29         for (i = 0; i < 16; i++) {
  30                 struct dma_info *info = get_dma_info(i);
  31                 struct dma_channel *channel = get_dma_channel(i);
  32
  33                 if (unlikely(!info) || !channel)
  34                         continue;
  35
  36                 len += sprintf(buf + len, "%2d: %14s    %s\n",
  37                                channel->chan, info->name,
  38                                channel->dev_id);
  39         }
  40
  41         return len;
  42 }
  43
  44 static DEVICE_ATTR(devices, S_IRUGO, dma_show_devices, NULL);
  45
  46 static int __init dma_subsys_init(void)
  47 {
  48         struct device *dev_root;
  49         int ret;
  50
  51         ret = subsys_system_register(&dma_subsys, NULL);
  52         if (unlikely(ret))
  53                 return ret;
  54
  55         dev_root = bus_get_dev_root(&dma_subsys);
  56         if (dev_root) {
  57                 ret = device_create_file(dev_root, &dev_attr_devices);
  58                 put_device(dev_root);
  59         }
  60         return ret;
  61 }
  62 postcore_initcall(dma_subsys_init);
  63
  64 static ssize_t dma_show_dev_id(struct device *dev,
  65                                 struct device_attribute *attr, char *buf)
  66 {
  67         struct dma_channel *channel = to_dma_channel(dev);
  68         return sprintf(buf, "%s\n", channel->dev_id);
  69 }
  70
  71 static ssize_t dma_store_dev_id(struct device *dev,
  72                                 struct device_attribute *attr,
  73                                 const char *buf, size_t count)
  74 {
  75         struct dma_channel *channel = to_dma_channel(dev);
  76         strcpy(channel->dev_id, buf);
  77         return count;
  78 }
  79
  80 static DEVICE_ATTR(dev_id, S_IRUGO | S_IWUSR, dma_show_dev_id, dma_store_dev_id);
  81
  82 static ssize_t dma_store_config(struct device *dev,
  83                                 struct device_attribute *attr,
  84                                 const char *buf, size_t count)
  85 {
  86         struct dma_channel *channel = to_dma_channel(dev);
  87         unsigned long config;
  88
  89         config = simple_strtoul(buf, NULL, 0);
  90         dma_configure_channel(channel->vchan, config);
  91
  92         return count;
  93 }
  94
  95 static DEVICE_ATTR(config, S_IWUSR, NULL, dma_store_config);
  96
  97 static ssize_t dma_show_mode(struct device *dev,
  98                                 struct device_attribute *attr, char *buf)
  99 {
 100         struct dma_channel *channel = to_dma_channel(dev);
 101         return sprintf(buf, "0x%08x\n", channel->mode);
 102 }
 103
 104 static ssize_t dma_store_mode(struct device *dev,
 105                               struct device_attribute *attr,
 106                               const char *buf, size_t count)
 107 {
 108         struct dma_channel *channel = to_dma_channel(dev);
 109         channel->mode = simple_strtoul(buf, NULL, 0);
 110         return count;
 111 }
 112
 113 static DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, dma_show_mode, dma_store_mode);
 114
 115 #define dma_ro_attr(field, fmt)                                         \
 116 static ssize_t dma_show_##field(struct device *dev,             \
 117                                 struct device_attribute *attr, char *buf)\
 118 {                                                                       \
 119         struct dma_channel *channel = to_dma_channel(dev);              \
 120         return sprintf(buf, fmt, channel->field);                       \
 121 }                                                                       \
 122 static DEVICE_ATTR(field, S_IRUGO, dma_show_##field, NULL);
 123
 124 dma_ro_attr(count, "0x%08x\n");
 125 dma_ro_attr(flags, "0x%08lx\n");
 126
 127 int dma_create_sysfs_files(struct dma_channel *chan, struct dma_info *info)
 128 {
 129         struct device *dev = &chan->dev;
 130         char name[16];
 131         int ret;
 132
 133         dev->id  = chan->vchan;
 134         dev->bus = &dma_subsys;
 135
 136         ret = device_register(dev);
 137         if (ret)
 138                 return ret;
 139
 140         ret |= device_create_file(dev, &dev_attr_dev_id);
 141         ret |= device_create_file(dev, &dev_attr_count);
 142         ret |= device_create_file(dev, &dev_attr_mode);
 143         ret |= device_create_file(dev, &dev_attr_flags);
 144         ret |= device_create_file(dev, &dev_attr_config);
 145
 146         if (unlikely(ret)) {
 147                 dev_err(&info->pdev->dev, "Failed creating attrs\n");
 148                 return ret;
 149         }
 150
 151         snprintf(name, sizeof(name), "dma%d", chan->chan);
 152         return sysfs_create_link(&info->pdev->dev.kobj, &dev->kobj, name);
 153 }
 154
 155 void dma_remove_sysfs_files(struct dma_channel *chan, struct dma_info *info)
 156 {
 157         struct device *dev = &chan->dev;
 158         char name[16];
 159
 160         device_remove_file(dev, &dev_attr_dev_id);
 161         device_remove_file(dev, &dev_attr_count);
 162         device_remove_file(dev, &dev_attr_mode);
 163         device_remove_file(dev, &dev_attr_flags);
 164         device_remove_file(dev, &dev_attr_config);
 165
 166         snprintf(name, sizeof(name), "dma%d", chan->chan);
 167         sysfs_remove_link(&info->pdev->dev.kobj, name);
 168
 169         device_unregister(dev);
 170 }