diff options
| -rw-r--r-- | arch/sh/drivers/dma/dma-api.c | 274 | ||||
| -rw-r--r-- | include/asm-sh/dma.h | 40 |
2 files changed, 218 insertions, 96 deletions
diff --git a/arch/sh/drivers/dma/dma-api.c b/arch/sh/drivers/dma/dma-api.c index 47c3e83..e062067 100644 --- a/arch/sh/drivers/dma/dma-api.c +++ b/arch/sh/drivers/dma/dma-api.c @@ -11,61 +11,27 @@ */ #include <linux/init.h> #include <linux/module.h> -#include <linux/interrupt.h> #include <linux/spinlock.h> #include <linux/proc_fs.h> #include <linux/list.h> #include <linux/platform_device.h> +#include <linux/mm.h> #include <asm/dma.h> DEFINE_SPINLOCK(dma_spin_lock); static LIST_HEAD(registered_dmac_list); -/* - * A brief note about the reasons for this API as it stands. - * - * For starters, the old ISA DMA API didn't work for us for a number of - * reasons, for one, the vast majority of channels on the SH DMAC are - * dual-address mode only, and both the new and the old DMA APIs are after the - * concept of managing a DMA buffer, which doesn't overly fit this model very - * well. In addition to which, the new API is largely geared at IOMMUs and - * GARTs, and doesn't even support the channel notion very well. - * - * The other thing that's a marginal issue, is the sheer number of random DMA - * engines that are present (ie, in boards like the Dreamcast), some of which - * cascade off of the SH DMAC, and others do not. As such, there was a real - * need for a scalable subsystem that could deal with both single and - * dual-address mode usage, in addition to interoperating with cascaded DMACs. - * - * There really isn't any reason why this needs to be SH specific, though I'm - * not aware of too many other processors (with the exception of some MIPS) - * that have the same concept of a dual address mode, or any real desire to - * actually make use of the DMAC even if such a subsystem were exposed - * elsewhere. - * - * The idea for this was derived from the ARM port, which acted as an excellent - * reference when trying to address these issues. - * - * It should also be noted that the decision to add Yet Another DMA API(tm) to - * the kernel wasn't made easily, and was only decided upon after conferring - * with jejb with regards to the state of the old and new APIs as they applied - * to these circumstances. Philip Blundell was also a great help in figuring - * out some single-address mode DMA semantics that were otherwise rather - * confusing. - */ - struct dma_info *get_dma_info(unsigned int chan) { struct dma_info *info; - unsigned int total = 0; /* * Look for each DMAC's range to determine who the owner of * the channel is. */ list_for_each_entry(info, ®istered_dmac_list, list) { - total += info->nr_channels; - if (chan > total) + if ((chan < info->first_channel_nr) || + (chan >= info->first_channel_nr + info->nr_channels)) continue; return info; @@ -73,6 +39,22 @@ struct dma_info *get_dma_info(unsigned int chan) 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) { @@ -91,63 +73,161 @@ static unsigned int get_nr_channels(void) struct dma_channel *get_dma_channel(unsigned int chan) { struct dma_info *info = get_dma_info(chan); + struct dma_channel *channel; + int i; - if (!info) + if (unlikely(!info)) return ERR_PTR(-EINVAL); - return info->channels + chan; + 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 = &info->channels[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); -int request_dma(unsigned int chan, const char *dev_id) +static int search_cap(const char **haystack, const char *needle) { - struct dma_info *info = get_dma_info(chan); - struct dma_channel *channel = &info->channels[chan]; + 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 capabilites + * + * 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; + } - down(&channel->sem); + if (info->ops->request) { + int result = info->ops->request(channel); + if (result) + return result; - if (!info->ops || chan >= MAX_DMA_CHANNELS) { - up(&channel->sem); - return -EINVAL; + atomic_set(&channel->busy, 1); + return channel->chan; } - atomic_set(&channel->busy, 1); + 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)); - up(&channel->sem); + if (info->ops->request) { + result = info->ops->request(channel); + if (result) + atomic_set(&channel->busy, 0); - if (info->ops->request) - return info->ops->request(channel); + 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 = &info->channels[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 = &info->channels[chan]; + struct dma_channel *channel = get_dma_channel(chan); if (channel->flags & DMA_TEI_CAPABLE) { wait_event(channel->wait_queue, @@ -158,21 +238,52 @@ void dma_wait_for_completion(unsigned int chan) 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 = &info->channels[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 = &info->channels[chan]; + struct dma_channel *channel = get_dma_channel(chan); channel->sar = from; channel->dar = to; @@ -181,8 +292,20 @@ int dma_xfer(unsigned int chan, unsigned long from, 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); -#ifdef CONFIG_PROC_FS static int dma_read_proc(char *buf, char **start, off_t off, int len, int *eof, void *data) { @@ -214,8 +337,6 @@ static int dma_read_proc(char *buf, char **start, off_t off, return p - buf; } -#endif - int register_dmac(struct dma_info *info) { @@ -224,8 +345,7 @@ int register_dmac(struct dma_info *info) 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" : ""); + info->name, info->nr_channels, info->nr_channels > 1 ? "s" : ""); BUG_ON((info->flags & DMAC_CHANNELS_CONFIGURED) && !info->channels); @@ -242,28 +362,26 @@ int register_dmac(struct dma_info *info) size = sizeof(struct dma_channel) * info->nr_channels; - info->channels = kmalloc(size, GFP_KERNEL); + info->channels = kzalloc(size, GFP_KERNEL); if (!info->channels) return -ENOMEM; - - memset(info->channels, 0, size); } total_channels = get_nr_channels(); for (i = 0; i < info->nr_channels; i++) { - struct dma_channel *chan = info->channels + i; + struct dma_channel *chan = &info->channels[i]; + + atomic_set(&chan->busy, 0); - chan->chan = i; - chan->vchan = i + total_channels; + 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_MUTEX(&chan->sem); init_waitqueue_head(&chan->wait_queue); - dma_create_sysfs_files(chan, info); } @@ -271,6 +389,7 @@ int register_dmac(struct dma_info *info) return 0; } +EXPORT_SYMBOL(register_dmac); void unregister_dmac(struct dma_info *info) { @@ -285,31 +404,16 @@ void unregister_dmac(struct dma_info *info) list_del(&info->list); platform_device_unregister(info->pdev); } +EXPORT_SYMBOL(unregister_dmac); static int __init dma_api_init(void) { - printk("DMA: Registering DMA API.\n"); - -#ifdef CONFIG_PROC_FS + printk(KERN_NOTICE "DMA: Registering DMA API.\n"); create_proc_read_entry("dma", 0, 0, dma_read_proc, 0); -#endif - return 0; } - subsys_initcall(dma_api_init); MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); MODULE_DESCRIPTION("DMA API for SuperH"); MODULE_LICENSE("GPL"); - -EXPORT_SYMBOL(request_dma); -EXPORT_SYMBOL(free_dma); -EXPORT_SYMBOL(register_dmac); -EXPORT_SYMBOL(get_dma_residue); -EXPORT_SYMBOL(get_dma_info); -EXPORT_SYMBOL(get_dma_channel); -EXPORT_SYMBOL(dma_xfer); -EXPORT_SYMBOL(dma_wait_for_completion); -EXPORT_SYMBOL(dma_configure_channel); - diff --git a/include/asm-sh/dma.h b/include/asm-sh/dma.h index d9daa02..faf3051 100644 --- a/include/asm-sh/dma.h +++ b/include/asm-sh/dma.h @@ -14,9 +14,7 @@ #include <linux/spinlock.h> #include <linux/wait.h> #include <linux/sysdev.h> -#include <linux/device.h> #include <asm/cpu/dma.h> -#include <asm/semaphore.h> /* The maximum address that we can perform a DMA transfer to on this platform */ /* Don't define MAX_DMA_ADDRESS; it's useless on the SuperH and any @@ -46,16 +44,21 @@ * DMAC (dma_info) flags */ enum { - DMAC_CHANNELS_CONFIGURED = 0x00, - DMAC_CHANNELS_TEI_CAPABLE = 0x01, + DMAC_CHANNELS_CONFIGURED = 0x01, + DMAC_CHANNELS_TEI_CAPABLE = 0x02, /* Transfer end interrupt */ }; /* * DMA channel capabilities / flags */ enum { - DMA_TEI_CAPABLE = 0x01, - DMA_CONFIGURED = 0x02, + DMA_CONFIGURED = 0x01, + + /* + * Transfer end interrupt, inherited from DMAC. + * wait_queue used in dma_wait_for_completion. + */ + DMA_TEI_CAPABLE = 0x02, }; extern spinlock_t dma_spin_lock; @@ -68,28 +71,31 @@ struct dma_ops { int (*get_residue)(struct dma_channel *chan); int (*xfer)(struct dma_channel *chan); - void (*configure)(struct dma_channel *chan, unsigned long flags); + int (*configure)(struct dma_channel *chan, unsigned long flags); + int (*extend)(struct dma_channel *chan, unsigned long op, void *param); }; struct dma_channel { - char dev_id[16]; + char dev_id[16]; /* unique name per DMAC of channel */ - unsigned int chan; /* Physical channel number */ + unsigned int chan; /* DMAC channel number */ unsigned int vchan; /* Virtual channel number */ + unsigned int mode; unsigned int count; unsigned long sar; unsigned long dar; + const char **caps; + unsigned long flags; atomic_t busy; - struct semaphore sem; wait_queue_head_t wait_queue; struct sys_device dev; - char *name; + void *priv_data; }; struct dma_info { @@ -103,6 +109,12 @@ struct dma_info { struct dma_channel *channels; struct list_head list; + int first_channel_nr; +}; + +struct dma_chan_caps { + int ch_num; + const char **caplist; }; #define to_dma_channel(channel) container_of(channel, struct dma_channel, dev) @@ -121,6 +133,8 @@ extern int dma_xfer(unsigned int chan, unsigned long from, #define dma_read_page(chan, from, to) \ dma_read(chan, from, to, PAGE_SIZE) +extern int request_dma_bycap(const char **dmac, const char **caps, + const char *dev_id); extern int request_dma(unsigned int chan, const char *dev_id); extern void free_dma(unsigned int chan); extern int get_dma_residue(unsigned int chan); @@ -131,6 +145,10 @@ extern void dma_configure_channel(unsigned int chan, unsigned long flags); extern int register_dmac(struct dma_info *info); extern void unregister_dmac(struct dma_info *info); +extern struct dma_info *get_dma_info_by_name(const char *dmac_name); + +extern int dma_extend(unsigned int chan, unsigned long op, void *param); +extern int register_chan_caps(const char *dmac, struct dma_chan_caps *capslist); #ifdef CONFIG_SYSFS /* arch/sh/drivers/dma/dma-sysfs.c */ |