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 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 } 171