diff options
author | Ralf Baechle <ralf@linux-mips.org> | 2000-07-21 22:00:56 +0000 |
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committer | Ralf Baechle <ralf@linux-mips.org> | 2000-07-21 22:00:56 +0000 |
commit | 168660f24dfc46c2702acbe4701a446f42a59578 (patch) | |
tree | f431368afbf6b1b71809cf3fd904d800ea126f4d /arch/arm/kernel/dma.c | |
parent | 6420f767924fa73b0ea267864d96820815f4ba5a (diff) |
Merge with Linux 2.4.0-test5-pre3.
Diffstat (limited to 'arch/arm/kernel/dma.c')
-rw-r--r-- | arch/arm/kernel/dma.c | 307 |
1 files changed, 180 insertions, 127 deletions
diff --git a/arch/arm/kernel/dma.c b/arch/arm/kernel/dma.c index ff8322d34..7ed4c28ca 100644 --- a/arch/arm/kernel/dma.c +++ b/arch/arm/kernel/dma.c @@ -1,130 +1,123 @@ /* * linux/arch/arm/kernel/dma.c * - * Copyright (C) 1995-1998 Russell King + * Copyright (C) 1995-2000 Russell King * - * Front-end to the DMA handling. You must provide the following - * architecture-specific routines: - * - * int arch_request_dma(dmach_t channel, dma_t *dma, const char *dev_id); - * void arch_free_dma(dmach_t channel, dma_t *dma); - * void arch_enable_dma(dmach_t channel, dma_t *dma); - * void arch_disable_dma(dmach_t channel, dma_t *dma); - * int arch_get_dma_residue(dmach_t channel, dma_t *dma); - * - * Moved DMA resource allocation here... + * Front-end to the DMA handling. This handles the allocation/freeing + * of DMA channels, and provides a unified interface to the machines + * DMA facilities. */ +#include <linux/module.h> #include <linux/malloc.h> #include <linux/sched.h> -#include <linux/module.h> #include <linux/mman.h> #include <linux/init.h> #include <linux/spinlock.h> -#include <asm/page.h> -#include <asm/irq.h> -#include <asm/hardware.h> -#include <asm/io.h> #include <asm/dma.h> - -/* A note on resource allocation: - * - * All drivers needing DMA channels, should allocate and release them - * through the public routines `request_dma()' and `free_dma()'. - * - * In order to avoid problems, all processes should allocate resources in - * the same sequence and release them in the reverse order. - * - * So, when allocating DMAs and IRQs, first allocate the IRQ, then the DMA. - * When releasing them, first release the DMA, then release the IRQ. - * If you don't, you may cause allocation requests to fail unnecessarily. - * This doesn't really matter now, but it will once we get real semaphores - * in the kernel. - */ - +#include "dma.h" spinlock_t dma_spin_lock = SPIN_LOCK_UNLOCKED; -#include "dma.h" - -const char dma_str[] = "%s: dma %d not supported\n"; +#if MAX_DMA_CHANNELS > 0 static dma_t dma_chan[MAX_DMA_CHANNELS]; -/* Get dma list - * for /proc/dma +/* + * Get dma list for /proc/dma */ int get_dma_list(char *buf) { - int i, len = 0; + dma_t *dma; + char *p = buf; + int i; - for (i = 0; i < MAX_DMA_CHANNELS; i++) { - if (dma_chan[i].lock) - len += sprintf(buf + len, "%2d: %s\n", - i, dma_chan[i].device_id); - } - return len; + for (i = 0, dma = dma_chan; i < MAX_DMA_CHANNELS; i++, dma++) + if (dma->lock) + p += sprintf(p, "%2d: %14s %s\n", i, + dma->d_ops->type, dma->device_id); + + return p - buf; } -/* Request DMA channel +/* + * Request DMA channel * * On certain platforms, we have to allocate an interrupt as well... */ int request_dma(dmach_t channel, const char *device_id) { - if (channel < MAX_DMA_CHANNELS) { - int ret; - - if (xchg(&dma_chan[channel].lock, 1) != 0) - return -EBUSY; - - ret = arch_request_dma(channel, &dma_chan[channel], device_id); - if (!ret) { - dma_chan[channel].device_id = device_id; - dma_chan[channel].active = 0; - dma_chan[channel].invalid = 1; - } else - xchg(&dma_chan[channel].lock, 0); - - return ret; - } else { - printk (KERN_ERR "Trying to allocate DMA%d\n", channel); - return -EINVAL; - } + dma_t *dma = dma_chan + channel; + int ret; + + if (channel >= MAX_DMA_CHANNELS || !dma->d_ops) + goto bad_dma; + + if (xchg(&dma->lock, 1) != 0) + goto busy; + + dma->device_id = device_id; + dma->active = 0; + dma->invalid = 1; + + ret = 0; + if (dma->d_ops->request) + ret = dma->d_ops->request(channel, dma); + + if (ret) + xchg(&dma->lock, 0); + + return ret; + +bad_dma: + printk(KERN_ERR "dma: trying to allocate DMA%d\n", channel); + return -EINVAL; + +busy: + return -EBUSY; } -/* Free DMA channel +/* + * Free DMA channel * * On certain platforms, we have to free interrupt as well... */ void free_dma(dmach_t channel) { - if (channel >= MAX_DMA_CHANNELS) { - printk (KERN_ERR "Trying to free DMA%d\n", channel); - return; - } + dma_t *dma = dma_chan + channel; + + if (channel >= MAX_DMA_CHANNELS || !dma->d_ops) + goto bad_dma; - if (xchg(&dma_chan[channel].lock, 0) == 0) { - if (dma_chan[channel].active) { - printk (KERN_ERR "Freeing active DMA%d\n", channel); - arch_disable_dma(channel, &dma_chan[channel]); - dma_chan[channel].active = 0; - } + if (dma->active) { + printk(KERN_ERR "dma%d: freeing active DMA\n", channel); + dma->d_ops->disable(channel, dma); + dma->active = 0; + } - printk (KERN_ERR "Trying to free free DMA%d\n", channel); + if (xchg(&dma->lock, 0) != 0) { + if (dma->d_ops->free) + dma->d_ops->free(channel, dma); return; } - arch_free_dma(channel, &dma_chan[channel]); + + printk(KERN_ERR "dma%d: trying to free free DMA\n", channel); + return; + +bad_dma: + printk(KERN_ERR "dma: trying to free DMA%d\n", channel); } /* Set DMA Scatter-Gather list */ void set_dma_sg (dmach_t channel, dmasg_t *sg, int nr_sg) { - dma_chan[channel].sg = sg; - dma_chan[channel].sgcount = nr_sg; - dma_chan[channel].invalid = 1; + dma_t *dma = dma_chan + channel; + + dma->sg = sg; + dma->sgcount = nr_sg; + dma->invalid = 1; } /* Set DMA address @@ -133,15 +126,16 @@ void set_dma_sg (dmach_t channel, dmasg_t *sg, int nr_sg) */ void set_dma_addr (dmach_t channel, unsigned long physaddr) { - if (dma_chan[channel].active) - printk(KERN_ERR "set_dma_addr: altering DMA%d" - " address while DMA active\n", - channel); - - dma_chan[channel].sg = &dma_chan[channel].buf; - dma_chan[channel].sgcount = 1; - dma_chan[channel].buf.address = physaddr; - dma_chan[channel].invalid = 1; + dma_t *dma = dma_chan + channel; + + if (dma->active) + printk(KERN_ERR "dma%d: altering DMA address while " + "DMA active\n", channel); + + dma->sg = &dma->buf; + dma->sgcount = 1; + dma->buf.address = physaddr; + dma->invalid = 1; } /* Set DMA byte count @@ -150,78 +144,137 @@ void set_dma_addr (dmach_t channel, unsigned long physaddr) */ void set_dma_count (dmach_t channel, unsigned long count) { - if (dma_chan[channel].active) - printk(KERN_ERR "set_dma_count: altering DMA%d" - " count while DMA active\n", - channel); - - dma_chan[channel].sg = &dma_chan[channel].buf; - dma_chan[channel].sgcount = 1; - dma_chan[channel].buf.length = count; - dma_chan[channel].invalid = 1; + dma_t *dma = dma_chan + channel; + + if (dma->active) + printk(KERN_ERR "dma%d: altering DMA count while " + "DMA active\n", channel); + + dma->sg = &dma->buf; + dma->sgcount = 1; + dma->buf.length = count; + dma->invalid = 1; } /* Set DMA direction mode */ void set_dma_mode (dmach_t channel, dmamode_t mode) { - if (dma_chan[channel].active) - printk(KERN_ERR "set_dma_mode: altering DMA%d" - " mode while DMA active\n", - channel); + dma_t *dma = dma_chan + channel; + + if (dma->active) + printk(KERN_ERR "dma%d: altering DMA mode while " + "DMA active\n", channel); - dma_chan[channel].dma_mode = mode; - dma_chan[channel].invalid = 1; + dma->dma_mode = mode; + dma->invalid = 1; } /* Enable DMA channel */ void enable_dma (dmach_t channel) { - if (dma_chan[channel].lock) { - if (dma_chan[channel].active == 0) { - dma_chan[channel].active = 1; - arch_enable_dma(channel, &dma_chan[channel]); - } - } else - printk (KERN_ERR "Trying to enable free DMA%d\n", channel); + dma_t *dma = dma_chan + channel; + + if (!dma->lock) + goto free_dma; + + if (dma->active == 0) { + dma->active = 1; + dma->d_ops->enable(channel, dma); + } + return; + +free_dma: + printk(KERN_ERR "dma%d: trying to enable free DMA\n", channel); + BUG(); } /* Disable DMA channel */ void disable_dma (dmach_t channel) { - if (dma_chan[channel].lock) { - if (dma_chan[channel].active == 1) { - dma_chan[channel].active = 0; - arch_disable_dma(channel, &dma_chan[channel]); - } - } else - printk (KERN_ERR "Trying to disable free DMA%d\n", channel); + dma_t *dma = dma_chan + channel; + + if (!dma->lock) + goto free_dma; + + if (dma->active == 1) { + dma->active = 0; + dma->d_ops->disable(channel, dma); + } + return; + +free_dma: + printk(KERN_ERR "dma%d: trying to disable free DMA\n", channel); + BUG(); +} + +void set_dma_page(dmach_t channel, char pagenr) +{ + printk(KERN_ERR "dma%d: trying to set_dma_page\n", channel); } void set_dma_speed(dmach_t channel, int cycle_ns) { - dma_chan[channel].speed = - arch_set_dma_speed(channel, &dma_chan[channel], cycle_ns); + dma_t *dma = dma_chan + channel; + int ret = 0; + + if (dma->d_ops->setspeed) + ret = dma->d_ops->setspeed(channel, dma, cycle_ns); + dma->speed = ret; } int get_dma_residue(dmach_t channel) { - return arch_get_dma_residue(channel, &dma_chan[channel]); + dma_t *dma = dma_chan + channel; + int ret = 0; + + if (dma->d_ops->residue) + ret = dma->d_ops->residue(channel, dma); + + return ret; +} + +void __init init_dma(void) +{ + arch_dma_init(dma_chan); +} + +#else + +int request_dma(dmach_t channel, const char *device_id) +{ + return -EINVAL; +} + +static int no_dma(void) +{ + return 0; } -EXPORT_SYMBOL(dma_str); +#define GLOBAL_ALIAS(_a,_b) asm (".set " #_a "," #_b "; .globl " #_a) +GLOBAL_ALIAS(disable_dma, no_dma); +GLOBAL_ALIAS(enable_dma, no_dma); +GLOBAL_ALIAS(free_dma, no_dma); +GLOBAL_ALIAS(get_dma_residue, no_dma); +GLOBAL_ALIAS(get_dma_list, no_dma); +GLOBAL_ALIAS(set_dma_mode, no_dma); +GLOBAL_ALIAS(set_dma_page, no_dma); +GLOBAL_ALIAS(set_dma_count, no_dma); +GLOBAL_ALIAS(set_dma_addr, no_dma); +GLOBAL_ALIAS(set_dma_sg, no_dma); +GLOBAL_ALIAS(set_dma_speed, no_dma); +GLOBAL_ALIAS(init_dma, no_dma); + +#endif + EXPORT_SYMBOL(enable_dma); EXPORT_SYMBOL(disable_dma); EXPORT_SYMBOL(set_dma_addr); EXPORT_SYMBOL(set_dma_count); EXPORT_SYMBOL(set_dma_mode); +EXPORT_SYMBOL(set_dma_page); EXPORT_SYMBOL(get_dma_residue); EXPORT_SYMBOL(set_dma_sg); EXPORT_SYMBOL(set_dma_speed); - -void __init init_dma(void) -{ - arch_dma_init(dma_chan); -} |