1 // SPDX-License-Identifier: GPL-2.0
3  * arch/sh/drivers/dma/dma-api.c
5  * SuperH-specific DMA management API
19 #include <asm/dma.h>
33 		if ((chan <  info->first_vchannel_nr) ||  in get_dma_info()
34 		    (chan >= info->first_vchannel_nr + info->nr_channels))  in get_dma_info()
53 		nr += info->nr_channels;  in get_nr_channels()
65 		return ERR_PTR(-EINVAL);  in get_dma_channel()
67 	for (i = 0; i < info->nr_channels; i++) {  in get_dma_channel()
68 		channel = &info->channels[i];  in get_dma_channel()
69 		if (channel->vchan == chan)  in get_dma_channel()
82 	if (info->ops->get_residue)  in get_dma_residue()
83 		return info->ops->get_residue(channel);  in get_dma_residue()
96 	if (atomic_xchg(&channel->busy, 1))  in request_dma()
97 		return -EBUSY;  in request_dma()
99 	strscpy(channel->dev_id, dev_id, sizeof(channel->dev_id));  in request_dma()
101 	if (info->ops->request) {  in request_dma()
102 		result = info->ops->request(channel);  in request_dma()
104 			atomic_set(&channel->busy, 0);  in request_dma()
118 	if (info->ops->free)  in free_dma()
119 		info->ops->free(channel);  in free_dma()
121 	atomic_set(&channel->busy, 0);  in free_dma()
130 	if (channel->flags & DMA_TEI_CAPABLE) {  in dma_wait_for_completion()
131 		wait_event(channel->wait_queue,  in dma_wait_for_completion()
132 			   (info->ops->get_residue(channel) == 0));  in dma_wait_for_completion()
136 	while (info->ops->get_residue(channel))  in dma_wait_for_completion()
146 	if (info->ops->configure)  in dma_configure_channel()
147 		info->ops->configure(channel, flags);  in dma_configure_channel()
157 	channel->sar	= from;  in dma_xfer()
158 	channel->dar	= to;  in dma_xfer()
159 	channel->count	= size;  in dma_xfer()
160 	channel->mode	= mode;  in dma_xfer()
162 	return info->ops->xfer(channel);  in dma_xfer()
182 		for (i = 0; i < info->nr_channels; i++) {  in dma_proc_show()
183 			struct dma_channel *channel = info->channels + i;  in dma_proc_show()
185 			if (!(channel->flags & DMA_CONFIGURED))  in dma_proc_show()
189 				   info->name, channel->dev_id);  in dma_proc_show()
200 	INIT_LIST_HEAD(&info->list);  in register_dmac()
202 	printk(KERN_INFO "DMA: Registering %s handler (%d channel%s).\n",  in register_dmac()
203 	       info->name, info->nr_channels, info->nr_channels > 1 ? "s" : "");  in register_dmac()
205 	BUG_ON((info->flags & DMAC_CHANNELS_CONFIGURED) && !info->channels);  in register_dmac()
207 	info->pdev = platform_device_register_simple(info->name, -1,  in register_dmac()
209 	if (IS_ERR(info->pdev))  in register_dmac()
210 		return PTR_ERR(info->pdev);  in register_dmac()
213 	 * Don't touch pre-configured channels  in register_dmac()
215 	if (!(info->flags & DMAC_CHANNELS_CONFIGURED)) {  in register_dmac()
218 		size = sizeof(struct dma_channel) * info->nr_channels;  in register_dmac()
220 		info->channels = kzalloc(size, GFP_KERNEL);  in register_dmac()
221 		if (!info->channels)  in register_dmac()
222 			return -ENOMEM;  in register_dmac()
226 	info->first_vchannel_nr = total_channels;  in register_dmac()
227 	for (i = 0; i < info->nr_channels; i++) {  in register_dmac()
228 		struct dma_channel *chan = &info->channels[i];  in register_dmac()
230 		atomic_set(&chan->busy, 0);  in register_dmac()
232 		chan->chan  = info->first_channel_nr + i;  in register_dmac()
233 		chan->vchan = info->first_channel_nr + i + total_channels;  in register_dmac()
235 		memcpy(chan->dev_id, "Unused", 7);  in register_dmac()
237 		if (info->flags & DMAC_CHANNELS_TEI_CAPABLE)  in register_dmac()
238 			chan->flags |= DMA_TEI_CAPABLE;  in register_dmac()
240 		init_waitqueue_head(&chan->wait_queue);  in register_dmac()
244 	list_add(&info->list, &registered_dmac_list);  in register_dmac()
254 	for (i = 0; i < info->nr_channels; i++)  in unregister_dmac()
255 		dma_remove_sysfs_files(info->channels + i, info);  in unregister_dmac()
257 	if (!(info->flags & DMAC_CHANNELS_CONFIGURED))  in unregister_dmac()
258 		kfree(info->channels);  in unregister_dmac()
260 	list_del(&info->list);  in unregister_dmac()
261 	platform_device_unregister(info->pdev);  in unregister_dmac()
267 	printk(KERN_NOTICE "DMA: Registering DMA API.\n");  in dma_api_init()
268 	return proc_create_single("dma", 0, NULL, dma_proc_show) ? 0 : -ENOMEM;  in dma_api_init()
272 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
273 MODULE_DESCRIPTION("DMA API for SuperH");