| /* |
| * arch/sh/drivers/dma/dma-api.c |
| * |
| * SuperH-specific DMA management API |
| * |
| * Copyright (C) 2003, 2004, 2005 Paul Mundt |
| * |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| */ |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/spinlock.h> |
| #include <linux/proc_fs.h> |
| #include <linux/list.h> |
| #include <linux/platform_device.h> |
| #include <linux/mm.h> |
| #include <linux/sched.h> |
| #include <asm/dma.h> |
| |
| DEFINE_SPINLOCK(dma_spin_lock); |
| static LIST_HEAD(registered_dmac_list); |
| |
| struct dma_info *get_dma_info(unsigned int chan) |
| { |
| struct dma_info *info; |
| |
| /* |
| * Look for each DMAC's range to determine who the owner of |
| * the channel is. |
| */ |
| list_for_each_entry(info, ®istered_dmac_list, list) { |
| if ((chan < info->first_channel_nr) || |
| (chan >= info->first_channel_nr + info->nr_channels)) |
| continue; |
| |
| return info; |
| } |
| |
| return NULL; |
| } |
| EXPORT_SYMBOL(get_dma_info); |
| |
| struct dma_info *get_dma_info_by_name(const char *dmac_name) |
| { |
| struct dma_info *info; |
| |
| list_for_each_entry(info, ®istered_dmac_list, list) { |
| if (dmac_name && (strcmp(dmac_name, info->name) != 0)) |
| continue; |
| else |
| return info; |
| } |
| |
| return NULL; |
| } |
| EXPORT_SYMBOL(get_dma_info_by_name); |
| |
| static unsigned int get_nr_channels(void) |
| { |
| struct dma_info *info; |
| unsigned int nr = 0; |
| |
| if (unlikely(list_empty(®istered_dmac_list))) |
| return nr; |
| |
| list_for_each_entry(info, ®istered_dmac_list, list) |
| nr += info->nr_channels; |
| |
| return nr; |
| } |
| |
| struct dma_channel *get_dma_channel(unsigned int chan) |
| { |
| struct dma_info *info = get_dma_info(chan); |
| struct dma_channel *channel; |
| int i; |
| |
| if (unlikely(!info)) |
| return ERR_PTR(-EINVAL); |
| |
| for (i = 0; i < info->nr_channels; i++) { |
| channel = &info->channels[i]; |
| if (channel->chan == chan) |
| return channel; |
| } |
| |
| return NULL; |
| } |
| EXPORT_SYMBOL(get_dma_channel); |
| |
| int get_dma_residue(unsigned int chan) |
| { |
| struct dma_info *info = get_dma_info(chan); |
| struct dma_channel *channel = get_dma_channel(chan); |
| |
| if (info->ops->get_residue) |
| return info->ops->get_residue(channel); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(get_dma_residue); |
| |
| static int search_cap(const char **haystack, const char *needle) |
| { |
| const char **p; |
| |
| for (p = haystack; *p; p++) |
| if (strcmp(*p, needle) == 0) |
| return 1; |
| |
| return 0; |
| } |
| |
| /** |
| * request_dma_bycap - Allocate a DMA channel based on its capabilities |
| * @dmac: List of DMA controllers to search |
| * @caps: List of capabilities |
| * |
| * Search all channels of all DMA controllers to find a channel which |
| * matches the requested capabilities. The result is the channel |
| * number if a match is found, or %-ENODEV if no match is found. |
| * |
| * Note that not all DMA controllers export capabilities, in which |
| * case they can never be allocated using this API, and so |
| * request_dma() must be used specifying the channel number. |
| */ |
| int request_dma_bycap(const char **dmac, const char **caps, const char *dev_id) |
| { |
| unsigned int found = 0; |
| struct dma_info *info; |
| const char **p; |
| int i; |
| |
| BUG_ON(!dmac || !caps); |
| |
| list_for_each_entry(info, ®istered_dmac_list, list) |
| if (strcmp(*dmac, info->name) == 0) { |
| found = 1; |
| break; |
| } |
| |
| if (!found) |
| return -ENODEV; |
| |
| for (i = 0; i < info->nr_channels; i++) { |
| struct dma_channel *channel = &info->channels[i]; |
| |
| if (unlikely(!channel->caps)) |
| continue; |
| |
| for (p = caps; *p; p++) { |
| if (!search_cap(channel->caps, *p)) |
| break; |
| if (request_dma(channel->chan, dev_id) == 0) |
| return channel->chan; |
| } |
| } |
| |
| return -EINVAL; |
| } |
| EXPORT_SYMBOL(request_dma_bycap); |
| |
| int dmac_search_free_channel(const char *dev_id) |
| { |
| struct dma_channel *channel = { 0 }; |
| struct dma_info *info = get_dma_info(0); |
| int i; |
| |
| for (i = 0; i < info->nr_channels; i++) { |
| channel = &info->channels[i]; |
| if (unlikely(!channel)) |
| return -ENODEV; |
| |
| if (atomic_read(&channel->busy) == 0) |
| break; |
| } |
| |
| if (info->ops->request) { |
| int result = info->ops->request(channel); |
| if (result) |
| return result; |
| |
| atomic_set(&channel->busy, 1); |
| return channel->chan; |
| } |
| |
| return -ENOSYS; |
| } |
| |
| int request_dma(unsigned int chan, const char *dev_id) |
| { |
| struct dma_channel *channel = { 0 }; |
| struct dma_info *info = get_dma_info(chan); |
| int result; |
| |
| channel = get_dma_channel(chan); |
| if (atomic_xchg(&channel->busy, 1)) |
| return -EBUSY; |
| |
| strlcpy(channel->dev_id, dev_id, sizeof(channel->dev_id)); |
| |
| if (info->ops->request) { |
| result = info->ops->request(channel); |
| if (result) |
| atomic_set(&channel->busy, 0); |
| |
| return result; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(request_dma); |
| |
| void free_dma(unsigned int chan) |
| { |
| struct dma_info *info = get_dma_info(chan); |
| struct dma_channel *channel = get_dma_channel(chan); |
| |
| if (info->ops->free) |
| info->ops->free(channel); |
| |
| atomic_set(&channel->busy, 0); |
| } |
| EXPORT_SYMBOL(free_dma); |
| |
| void dma_wait_for_completion(unsigned int chan) |
| { |
| struct dma_info *info = get_dma_info(chan); |
| struct dma_channel *channel = get_dma_channel(chan); |
| |
| if (channel->flags & DMA_TEI_CAPABLE) { |
| wait_event(channel->wait_queue, |
| (info->ops->get_residue(channel) == 0)); |
| return; |
| } |
| |
| while (info->ops->get_residue(channel)) |
| cpu_relax(); |
| } |
| EXPORT_SYMBOL(dma_wait_for_completion); |
| |
| int register_chan_caps(const char *dmac, struct dma_chan_caps *caps) |
| { |
| struct dma_info *info; |
| unsigned int found = 0; |
| int i; |
| |
| list_for_each_entry(info, ®istered_dmac_list, list) |
| if (strcmp(dmac, info->name) == 0) { |
| found = 1; |
| break; |
| } |
| |
| if (unlikely(!found)) |
| return -ENODEV; |
| |
| for (i = 0; i < info->nr_channels; i++, caps++) { |
| struct dma_channel *channel; |
| |
| if ((info->first_channel_nr + i) != caps->ch_num) |
| return -EINVAL; |
| |
| channel = &info->channels[i]; |
| channel->caps = caps->caplist; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(register_chan_caps); |
| |
| void dma_configure_channel(unsigned int chan, unsigned long flags) |
| { |
| struct dma_info *info = get_dma_info(chan); |
| struct dma_channel *channel = get_dma_channel(chan); |
| |
| if (info->ops->configure) |
| info->ops->configure(channel, flags); |
| } |
| EXPORT_SYMBOL(dma_configure_channel); |
| |
| int dma_xfer(unsigned int chan, unsigned long from, |
| unsigned long to, size_t size, unsigned int mode) |
| { |
| struct dma_info *info = get_dma_info(chan); |
| struct dma_channel *channel = get_dma_channel(chan); |
| |
| channel->sar = from; |
| channel->dar = to; |
| channel->count = size; |
| channel->mode = mode; |
| |
| return info->ops->xfer(channel); |
| } |
| EXPORT_SYMBOL(dma_xfer); |
| |
| int dma_extend(unsigned int chan, unsigned long op, void *param) |
| { |
| struct dma_info *info = get_dma_info(chan); |
| struct dma_channel *channel = get_dma_channel(chan); |
| |
| if (info->ops->extend) |
| return info->ops->extend(channel, op, param); |
| |
| return -ENOSYS; |
| } |
| EXPORT_SYMBOL(dma_extend); |
| |
| static int dma_read_proc(char *buf, char **start, off_t off, |
| int len, int *eof, void *data) |
| { |
| struct dma_info *info; |
| char *p = buf; |
| |
| if (list_empty(®istered_dmac_list)) |
| return 0; |
| |
| /* |
| * Iterate over each registered DMAC |
| */ |
| list_for_each_entry(info, ®istered_dmac_list, list) { |
| int i; |
| |
| /* |
| * Iterate over each channel |
| */ |
| for (i = 0; i < info->nr_channels; i++) { |
| struct dma_channel *channel = info->channels + i; |
| |
| if (!(channel->flags & DMA_CONFIGURED)) |
| continue; |
| |
| p += sprintf(p, "%2d: %14s %s\n", i, |
| info->name, channel->dev_id); |
| } |
| } |
| |
| return p - buf; |
| } |
| |
| int register_dmac(struct dma_info *info) |
| { |
| unsigned int total_channels, i; |
| |
| INIT_LIST_HEAD(&info->list); |
| |
| printk(KERN_INFO "DMA: Registering %s handler (%d channel%s).\n", |
| info->name, info->nr_channels, info->nr_channels > 1 ? "s" : ""); |
| |
| BUG_ON((info->flags & DMAC_CHANNELS_CONFIGURED) && !info->channels); |
| |
| info->pdev = platform_device_register_simple((char *)info->name, -1, |
| NULL, 0); |
| if (IS_ERR(info->pdev)) |
| return PTR_ERR(info->pdev); |
| |
| /* |
| * Don't touch pre-configured channels |
| */ |
| if (!(info->flags & DMAC_CHANNELS_CONFIGURED)) { |
| unsigned int size; |
| |
| size = sizeof(struct dma_channel) * info->nr_channels; |
| |
| info->channels = kzalloc(size, GFP_KERNEL); |
| if (!info->channels) |
| return -ENOMEM; |
| } |
| |
| total_channels = get_nr_channels(); |
| for (i = 0; i < info->nr_channels; i++) { |
| struct dma_channel *chan = &info->channels[i]; |
| |
| atomic_set(&chan->busy, 0); |
| |
| chan->chan = info->first_channel_nr + i; |
| chan->vchan = info->first_channel_nr + i + total_channels; |
| |
| memcpy(chan->dev_id, "Unused", 7); |
| |
| if (info->flags & DMAC_CHANNELS_TEI_CAPABLE) |
| chan->flags |= DMA_TEI_CAPABLE; |
| |
| init_waitqueue_head(&chan->wait_queue); |
| dma_create_sysfs_files(chan, info); |
| } |
| |
| list_add(&info->list, ®istered_dmac_list); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(register_dmac); |
| |
| void unregister_dmac(struct dma_info *info) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < info->nr_channels; i++) |
| dma_remove_sysfs_files(info->channels + i, info); |
| |
| if (!(info->flags & DMAC_CHANNELS_CONFIGURED)) |
| kfree(info->channels); |
| |
| list_del(&info->list); |
| platform_device_unregister(info->pdev); |
| } |
| EXPORT_SYMBOL(unregister_dmac); |
| |
| static int __init dma_api_init(void) |
| { |
| printk(KERN_NOTICE "DMA: Registering DMA API.\n"); |
| create_proc_read_entry("dma", 0, 0, dma_read_proc, 0); |
| return 0; |
| } |
| subsys_initcall(dma_api_init); |
| |
| MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); |
| MODULE_DESCRIPTION("DMA API for SuperH"); |
| MODULE_LICENSE("GPL"); |