diff options
Diffstat (limited to 'arch/arm/mach-s3c2410/dma.c')
| -rw-r--r-- | arch/arm/mach-s3c2410/dma.c | 1210 |
1 files changed, 1210 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2410/dma.c b/arch/arm/mach-s3c2410/dma.c new file mode 100644 index 000000000000..bc229fab86d4 --- /dev/null +++ b/arch/arm/mach-s3c2410/dma.c @@ -0,0 +1,1210 @@ +/* linux/arch/arm/mach-bast/dma.c + * + * (c) 2003-2005 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + * + * S3C2410 DMA core + * + * http://www.simtec.co.uk/products/EB2410ITX/ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Changelog: + * 27-Feb-2005 BJD Added kmem cache for dma descriptors + * 18-Nov-2004 BJD Removed error for loading onto stopped channel + * 10-Nov-2004 BJD Ensure all external symbols exported for modules + * 10-Nov-2004 BJD Use sys_device and sysdev_class for power management + * 08-Aug-2004 BJD Apply rmk's suggestions + * 21-Jul-2004 BJD Ported to linux 2.6 + * 12-Jul-2004 BJD Finished re-write and change of API + * 06-Jul-2004 BJD Rewrote dma code to try and cope with various problems + * 23-May-2003 BJD Created file + * 19-Aug-2003 BJD Cleanup, header fix, added URL + * + * This file is based on the Sangwook Lee/Samsung patches, re-written due + * to various ommisions from the code (such as flexible dma configuration) + * for use with the BAST system board. + * + * The re-write is pretty much complete, and should be good enough for any + * possible DMA function + */ + +#include <linux/config.h> + +#ifdef CONFIG_S3C2410_DMA_DEBUG +#define DEBUG +#endif + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/sysdev.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/delay.h> + +#include <asm/system.h> +#include <asm/irq.h> +#include <asm/hardware.h> +#include <asm/io.h> +#include <asm/dma.h> + +#include <asm/mach/dma.h> +#include <asm/arch/map.h> + +/* io map for dma */ +static void __iomem *dma_base; +static kmem_cache_t *dma_kmem; + +/* dma channel state information */ +s3c2410_dma_chan_t s3c2410_chans[S3C2410_DMA_CHANNELS]; + +/* debugging functions */ + +#define BUF_MAGIC (0xcafebabe) + +#define dmawarn(fmt...) printk(KERN_DEBUG fmt) + +#define dma_regaddr(chan, reg) ((chan)->regs + (reg)) + +#if 1 +#define dma_wrreg(chan, reg, val) writel((val), (chan)->regs + (reg)) +#else +static inline void +dma_wrreg(s3c2410_dma_chan_t *chan, int reg, unsigned long val) +{ + pr_debug("writing %08x to register %08x\n",(unsigned int)val,reg); + writel(val, dma_regaddr(chan, reg)); +} + +#endif + +#define dma_rdreg(chan, reg) readl((chan)->regs + (reg)) + +/* captured register state for debug */ + +struct s3c2410_dma_regstate { + unsigned long dcsrc; + unsigned long disrc; + unsigned long dstat; + unsigned long dcon; + unsigned long dmsktrig; +}; + +#ifdef CONFIG_S3C2410_DMA_DEBUG + +/* dmadbg_showregs + * + * simple debug routine to print the current state of the dma registers +*/ + +static void +dmadbg_capture(s3c2410_dma_chan_t *chan, struct s3c2410_dma_regstate *regs) +{ + regs->dcsrc = dma_rdreg(chan, S3C2410_DMA_DCSRC); + regs->disrc = dma_rdreg(chan, S3C2410_DMA_DISRC); + regs->dstat = dma_rdreg(chan, S3C2410_DMA_DSTAT); + regs->dcon = dma_rdreg(chan, S3C2410_DMA_DCON); + regs->dmsktrig = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); +} + +static void +dmadbg_showregs(const char *fname, int line, s3c2410_dma_chan_t *chan, + struct s3c2410_dma_regstate *regs) +{ + printk(KERN_DEBUG "dma%d: %s:%d: DCSRC=%08lx, DISRC=%08lx, DSTAT=%08lx DMT=%02lx, DCON=%08lx\n", + chan->number, fname, line, + regs->dcsrc, regs->disrc, regs->dstat, regs->dmsktrig, + regs->dcon); +} + +static void +dmadbg_showchan(const char *fname, int line, s3c2410_dma_chan_t *chan) +{ + struct s3c2410_dma_regstate state; + + dmadbg_capture(chan, &state); + + printk(KERN_DEBUG "dma%d: %s:%d: ls=%d, cur=%p, %p %p\n", + chan->number, fname, line, chan->load_state, + chan->curr, chan->next, chan->end); + + dmadbg_showregs(fname, line, chan, &state); +} + +#define dbg_showregs(chan) dmadbg_showregs(__FUNCTION__, __LINE__, (chan)) +#define dbg_showchan(chan) dmadbg_showchan(__FUNCTION__, __LINE__, (chan)) +#else +#define dbg_showregs(chan) do { } while(0) +#define dbg_showchan(chan) do { } while(0) +#endif /* CONFIG_S3C2410_DMA_DEBUG */ + +#define check_channel(chan) \ + do { if ((chan) >= S3C2410_DMA_CHANNELS) { \ + printk(KERN_ERR "%s: invalid channel %d\n", __FUNCTION__, (chan)); \ + return -EINVAL; \ + } } while(0) + + +/* s3c2410_dma_stats_timeout + * + * Update DMA stats from timeout info +*/ + +static void +s3c2410_dma_stats_timeout(s3c2410_dma_stats_t *stats, int val) +{ + if (stats == NULL) + return; + + if (val > stats->timeout_longest) + stats->timeout_longest = val; + if (val < stats->timeout_shortest) + stats->timeout_shortest = val; + + stats->timeout_avg += val; +} + +/* s3c2410_dma_waitforload + * + * wait for the DMA engine to load a buffer, and update the state accordingly +*/ + +static int +s3c2410_dma_waitforload(s3c2410_dma_chan_t *chan, int line) +{ + int timeout = chan->load_timeout; + int took; + + if (chan->load_state != S3C2410_DMALOAD_1LOADED) { + printk(KERN_ERR "dma%d: s3c2410_dma_waitforload() called in loadstate %d from line %d\n", chan->number, chan->load_state, line); + return 0; + } + + if (chan->stats != NULL) + chan->stats->loads++; + + while (--timeout > 0) { + if ((dma_rdreg(chan, S3C2410_DMA_DSTAT) << (32-20)) != 0) { + took = chan->load_timeout - timeout; + + s3c2410_dma_stats_timeout(chan->stats, took); + + switch (chan->load_state) { + case S3C2410_DMALOAD_1LOADED: + chan->load_state = S3C2410_DMALOAD_1RUNNING; + break; + + default: + printk(KERN_ERR "dma%d: unknown load_state in s3c2410_dma_waitforload() %d\n", chan->number, chan->load_state); + } + + return 1; + } + } + + if (chan->stats != NULL) { + chan->stats->timeout_failed++; + } + + return 0; +} + + + +/* s3c2410_dma_loadbuffer + * + * load a buffer, and update the channel state +*/ + +static inline int +s3c2410_dma_loadbuffer(s3c2410_dma_chan_t *chan, + s3c2410_dma_buf_t *buf) +{ + unsigned long reload; + + pr_debug("s3c2410_chan_loadbuffer: loading buff %p (0x%08lx,0x%06x)\n", + buf, (unsigned long)buf->data, buf->size); + + if (buf == NULL) { + dmawarn("buffer is NULL\n"); + return -EINVAL; + } + + /* check the state of the channel before we do anything */ + + if (chan->load_state == S3C2410_DMALOAD_1LOADED) { + dmawarn("load_state is S3C2410_DMALOAD_1LOADED\n"); + } + + if (chan->load_state == S3C2410_DMALOAD_1LOADED_1RUNNING) { + dmawarn("state is S3C2410_DMALOAD_1LOADED_1RUNNING\n"); + } + + /* it would seem sensible if we are the last buffer to not bother + * with the auto-reload bit, so that the DMA engine will not try + * and load another transfer after this one has finished... + */ + if (chan->load_state == S3C2410_DMALOAD_NONE) { + pr_debug("load_state is none, checking for noreload (next=%p)\n", + buf->next); + reload = (buf->next == NULL) ? S3C2410_DCON_NORELOAD : 0; + } else { + pr_debug("load_state is %d => autoreload\n", chan->load_state); + reload = S3C2410_DCON_AUTORELOAD; + } + + writel(buf->data, chan->addr_reg); + + dma_wrreg(chan, S3C2410_DMA_DCON, + chan->dcon | reload | (buf->size/chan->xfer_unit)); + + chan->next = buf->next; + + /* update the state of the channel */ + + switch (chan->load_state) { + case S3C2410_DMALOAD_NONE: + chan->load_state = S3C2410_DMALOAD_1LOADED; + break; + + case S3C2410_DMALOAD_1RUNNING: + chan->load_state = S3C2410_DMALOAD_1LOADED_1RUNNING; + break; + + default: + dmawarn("dmaload: unknown state %d in loadbuffer\n", + chan->load_state); + break; + } + + return 0; +} + +/* s3c2410_dma_call_op + * + * small routine to call the op routine with the given op if it has been + * registered +*/ + +static void +s3c2410_dma_call_op(s3c2410_dma_chan_t *chan, s3c2410_chan_op_t op) +{ + if (chan->op_fn != NULL) { + (chan->op_fn)(chan, op); + } +} + +/* s3c2410_dma_buffdone + * + * small wrapper to check if callback routine needs to be called, and + * if so, call it +*/ + +static inline void +s3c2410_dma_buffdone(s3c2410_dma_chan_t *chan, s3c2410_dma_buf_t *buf, + s3c2410_dma_buffresult_t result) +{ + pr_debug("callback_fn=%p, buf=%p, id=%p, size=%d, result=%d\n", + chan->callback_fn, buf, buf->id, buf->size, result); + + if (chan->callback_fn != NULL) { + (chan->callback_fn)(chan, buf->id, buf->size, result); + } +} + +/* s3c2410_dma_start + * + * start a dma channel going +*/ + +static int s3c2410_dma_start(s3c2410_dma_chan_t *chan) +{ + unsigned long tmp; + unsigned long flags; + + pr_debug("s3c2410_start_dma: channel=%d\n", chan->number); + + local_irq_save(flags); + + if (chan->state == S3C2410_DMA_RUNNING) { + pr_debug("s3c2410_start_dma: already running (%d)\n", chan->state); + local_irq_restore(flags); + return 0; + } + + chan->state = S3C2410_DMA_RUNNING; + + /* check wether there is anything to load, and if not, see + * if we can find anything to load + */ + + if (chan->load_state == S3C2410_DMALOAD_NONE) { + if (chan->next == NULL) { + printk(KERN_ERR "dma%d: channel has nothing loaded\n", + chan->number); + chan->state = S3C2410_DMA_IDLE; + local_irq_restore(flags); + return -EINVAL; + } + + s3c2410_dma_loadbuffer(chan, chan->next); + } + + dbg_showchan(chan); + + /* enable the channel */ + + if (!chan->irq_enabled) { + enable_irq(chan->irq); + chan->irq_enabled = 1; + } + + /* start the channel going */ + + tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); + tmp &= ~S3C2410_DMASKTRIG_STOP; + tmp |= S3C2410_DMASKTRIG_ON; + dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp); + + pr_debug("wrote %08lx to DMASKTRIG\n", tmp); + +#if 0 + /* the dma buffer loads should take care of clearing the AUTO + * reloading feature */ + tmp = dma_rdreg(chan, S3C2410_DMA_DCON); + tmp &= ~S3C2410_DCON_NORELOAD; + dma_wrreg(chan, S3C2410_DMA_DCON, tmp); +#endif + + s3c2410_dma_call_op(chan, S3C2410_DMAOP_START); + + dbg_showchan(chan); + + local_irq_restore(flags); + return 0; +} + +/* s3c2410_dma_canload + * + * work out if we can queue another buffer into the DMA engine +*/ + +static int +s3c2410_dma_canload(s3c2410_dma_chan_t *chan) +{ + if (chan->load_state == S3C2410_DMALOAD_NONE || + chan->load_state == S3C2410_DMALOAD_1RUNNING) + return 1; + + return 0; +} + + +/* s3c2410_dma_enqueue + * + * queue an given buffer for dma transfer. + * + * id the device driver's id information for this buffer + * data the physical address of the buffer data + * size the size of the buffer in bytes + * + * If the channel is not running, then the flag S3C2410_DMAF_AUTOSTART + * is checked, and if set, the channel is started. If this flag isn't set, + * then an error will be returned. + * + * It is possible to queue more than one DMA buffer onto a channel at + * once, and the code will deal with the re-loading of the next buffer + * when necessary. +*/ + +int s3c2410_dma_enqueue(unsigned int channel, void *id, + dma_addr_t data, int size) +{ + s3c2410_dma_chan_t *chan = &s3c2410_chans[channel]; + s3c2410_dma_buf_t *buf; + unsigned long flags; + + check_channel(channel); + + pr_debug("%s: id=%p, data=%08x, size=%d\n", + __FUNCTION__, id, (unsigned int)data, size); + + buf = kmem_cache_alloc(dma_kmem, GFP_ATOMIC); + if (buf == NULL) { + pr_debug("%s: out of memory (%d alloc)\n", + __FUNCTION__, sizeof(*buf)); + return -ENOMEM; + } + + pr_debug("%s: new buffer %p\n", __FUNCTION__, buf); + + //dbg_showchan(chan); + + buf->next = NULL; + buf->data = buf->ptr = data; + buf->size = size; + buf->id = id; + buf->magic = BUF_MAGIC; + + local_irq_save(flags); + + if (chan->curr == NULL) { + /* we've got nothing loaded... */ + pr_debug("%s: buffer %p queued onto empty channel\n", + __FUNCTION__, buf); + + chan->curr = buf; + chan->end = buf; + chan->next = NULL; + } else { + pr_debug("dma%d: %s: buffer %p queued onto non-empty channel\n", + chan->number, __FUNCTION__, buf); + + if (chan->end == NULL) + pr_debug("dma%d: %s: %p not empty, and chan->end==NULL?\n", + chan->number, __FUNCTION__, chan); + + chan->end->next = buf; + chan->end = buf; + } + + /* if necessary, update the next buffer field */ + if (chan->next == NULL) + chan->next = buf; + + /* check to see if we can load a buffer */ + if (chan->state == S3C2410_DMA_RUNNING) { + if (chan->load_state == S3C2410_DMALOAD_1LOADED && 1) { + if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { + printk(KERN_ERR "dma%d: loadbuffer:" + "timeout loading buffer\n", + chan->number); + dbg_showchan(chan); + local_irq_restore(flags); + return -EINVAL; + } + } + + while (s3c2410_dma_canload(chan) && chan->next != NULL) { + s3c2410_dma_loadbuffer(chan, chan->next); + } + } else if (chan->state == S3C2410_DMA_IDLE) { + if (chan->flags & S3C2410_DMAF_AUTOSTART) { + s3c2410_dma_ctrl(chan->number, S3C2410_DMAOP_START); + } + } + + local_irq_restore(flags); + return 0; +} + +EXPORT_SYMBOL(s3c2410_dma_enqueue); + +static inline void +s3c2410_dma_freebuf(s3c2410_dma_buf_t *buf) +{ + int magicok = (buf->magic == BUF_MAGIC); + + buf->magic = -1; + + if (magicok) { + kmem_cache_free(dma_kmem, buf); + } else { + printk("s3c2410_dma_freebuf: buff %p with bad magic\n", buf); + } +} + +/* s3c2410_dma_lastxfer + * + * called when the system is out of buffers, to ensure that the channel + * is prepared for shutdown. +*/ + +static inline void +s3c2410_dma_lastxfer(s3c2410_dma_chan_t *chan) +{ + pr_debug("dma%d: s3c2410_dma_lastxfer: load_state %d\n", + chan->number, chan->load_state); + + switch (chan->load_state) { + case S3C2410_DMALOAD_NONE: + break; + + case S3C2410_DMALOAD_1LOADED: + if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { + /* flag error? */ + printk(KERN_ERR "dma%d: timeout waiting for load\n", + chan->number); + return; + } + break; + + default: + pr_debug("dma%d: lastxfer: unhandled load_state %d with no next", + chan->number, chan->load_state); + return; + + } + + /* hopefully this'll shut the damned thing up after the transfer... */ + dma_wrreg(chan, S3C2410_DMA_DCON, chan->dcon | S3C2410_DCON_NORELOAD); +} + + +#define dmadbg2(x...) + +static irqreturn_t +s3c2410_dma_irq(int irq, void *devpw, struct pt_regs *regs) +{ + s3c2410_dma_chan_t *chan = (s3c2410_dma_chan_t *)devpw; + s3c2410_dma_buf_t *buf; + + buf = chan->curr; + + dbg_showchan(chan); + + /* modify the channel state */ + + switch (chan->load_state) { + case S3C2410_DMALOAD_1RUNNING: + /* TODO - if we are running only one buffer, we probably + * want to reload here, and then worry about the buffer + * callback */ + + chan->load_state = S3C2410_DMALOAD_NONE; + break; + + case S3C2410_DMALOAD_1LOADED: + /* iirc, we should go back to NONE loaded here, we + * had a buffer, and it was never verified as being + * loaded. + */ + + chan->load_state = S3C2410_DMALOAD_NONE; + break; + + case S3C2410_DMALOAD_1LOADED_1RUNNING: + /* we'll worry about checking to see if another buffer is + * ready after we've called back the owner. This should + * ensure we do not wait around too long for the DMA + * engine to start the next transfer + */ + + chan->load_state = S3C2410_DMALOAD_1LOADED; + break; + + case S3C2410_DMALOAD_NONE: + printk(KERN_ERR "dma%d: IRQ with no loaded buffer?\n", + chan->number); + break; + + default: + printk(KERN_ERR "dma%d: IRQ in invalid load_state %d\n", + chan->number, chan->load_state); + break; + } + + if (buf != NULL) { + /* update the chain to make sure that if we load any more + * buffers when we call the callback function, things should + * work properly */ + + chan->curr = buf->next; + buf->next = NULL; + + if (buf->magic != BUF_MAGIC) { + printk(KERN_ERR "dma%d: %s: buf %p incorrect magic\n", + chan->number, __FUNCTION__, buf); + return IRQ_HANDLED; + } + + s3c2410_dma_buffdone(chan, buf, S3C2410_RES_OK); + + /* free resouces */ + s3c2410_dma_freebuf(buf); + } else { + } + + if (chan->next != NULL) { + unsigned long flags; + + switch (chan->load_state) { + case S3C2410_DMALOAD_1RUNNING: + /* don't need to do anything for this state */ + break; + + case S3C2410_DMALOAD_NONE: + /* can load buffer immediately */ + break; + + case S3C2410_DMALOAD_1LOADED: + if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { + /* flag error? */ + printk(KERN_ERR "dma%d: timeout waiting for load\n", + chan->number); + return IRQ_HANDLED; + } + + break; + + case S3C2410_DMALOAD_1LOADED_1RUNNING: + goto no_load; + + default: + printk(KERN_ERR "dma%d: unknown load_state in irq, %d\n", + chan->number, chan->load_state); + return IRQ_HANDLED; + } + + local_irq_save(flags); + s3c2410_dma_loadbuffer(chan, chan->next); + local_irq_restore(flags); + } else { + s3c2410_dma_lastxfer(chan); + + /* see if we can stop this channel.. */ + if (chan->load_state == S3C2410_DMALOAD_NONE) { + pr_debug("dma%d: end of transfer, stopping channel (%ld)\n", + chan->number, jiffies); + s3c2410_dma_ctrl(chan->number, S3C2410_DMAOP_STOP); + } + } + + no_load: + return IRQ_HANDLED; +} + + + +/* s3c2410_request_dma + * + * get control of an dma channel +*/ + +int s3c2410_dma_request(unsigned int channel, s3c2410_dma_client_t *client, + void *dev) +{ + s3c2410_dma_chan_t *chan = &s3c2410_chans[channel]; + unsigned long flags; + int err; + + pr_debug("dma%d: s3c2410_request_dma: client=%s, dev=%p\n", + channel, client->name, dev); + + check_channel(channel); + + local_irq_save(flags); + + dbg_showchan(chan); + + if (chan->in_use) { + if (client != chan->client) { + printk(KERN_ERR "dma%d: already in use\n", channel); + local_irq_restore(flags); + return -EBUSY; + } else { + printk(KERN_ERR "dma%d: client already has channel\n", channel); + } + } + + chan->client = client; + chan->in_use = 1; + + if (!chan->irq_claimed) { + pr_debug("dma%d: %s : requesting irq %d\n", + channel, __FUNCTION__, chan->irq); + + err = request_irq(chan->irq, s3c2410_dma_irq, SA_INTERRUPT, + client->name, (void *)chan); + + if (err) { + chan->in_use = 0; + local_irq_restore(flags); + + printk(KERN_ERR "%s: cannot get IRQ %d for DMA %d\n", + client->name, chan->irq, chan->number); + return err; + } + + chan->irq_claimed = 1; + chan->irq_enabled = 1; + } + + local_irq_restore(flags); + + /* need to setup */ + + pr_debug("%s: channel initialised, %p\n", __FUNCTION__, chan); + + return 0; +} + +EXPORT_SYMBOL(s3c2410_dma_request); + +/* s3c2410_dma_free + * + * release the given channel back to the system, will stop and flush + * any outstanding transfers, and ensure the channel is ready for the + * next claimant. + * + * Note, although a warning is currently printed if the freeing client + * info is not the same as the registrant's client info, the free is still + * allowed to go through. +*/ + +int s3c2410_dma_free(dmach_t channel, s3c2410_dma_client_t *client) +{ + s3c2410_dma_chan_t *chan = &s3c2410_chans[channel]; + unsigned long flags; + + check_channel(channel); + + local_irq_save(flags); + + + if (chan->client != client) { + printk(KERN_WARNING "dma%d: possible free from different client (channel %p, passed %p)\n", + channel, chan->client, client); + } + + /* sort out stopping and freeing the channel */ + + if (chan->state != S3C2410_DMA_IDLE) { + pr_debug("%s: need to stop dma channel %p\n", + __FUNCTION__, chan); + + /* possibly flush the channel */ + s3c2410_dma_ctrl(channel, S3C2410_DMAOP_STOP); + } + + chan->client = NULL; + chan->in_use = 0; + + local_irq_restore(flags); + + return 0; +} + +EXPORT_SYMBOL(s3c2410_dma_free); + +static int s3c2410_dma_dostop(s3c2410_dma_chan_t *chan) +{ + unsigned long tmp; + unsigned long flags; + + pr_debug("%s:\n", __FUNCTION__); + + dbg_showchan(chan); + + local_irq_save(flags); + + s3c2410_dma_call_op(chan, S3C2410_DMAOP_STOP); + + tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); + tmp |= S3C2410_DMASKTRIG_STOP; + dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp); + +#if 0 + /* should also clear interrupts, according to WinCE BSP */ + tmp = dma_rdreg(chan, S3C2410_DMA_DCON); + tmp |= S3C2410_DCON_NORELOAD; + dma_wrreg(chan, S3C2410_DMA_DCON, tmp); +#endif + + chan->state = S3C2410_DMA_IDLE; + chan->load_state = S3C2410_DMALOAD_NONE; + + local_irq_restore(flags); + + return 0; +} + +/* s3c2410_dma_flush + * + * stop the channel, and remove all current and pending transfers +*/ + +static int s3c2410_dma_flush(s3c2410_dma_chan_t *chan) +{ + s3c2410_dma_buf_t *buf, *next; + unsigned long flags; + + pr_debug("%s:\n", __FUNCTION__); + + local_irq_save(flags); + + if (chan->state != S3C2410_DMA_IDLE) { + pr_debug("%s: stopping channel...\n", __FUNCTION__ ); + s3c2410_dma_ctrl(chan->number, S3C2410_DMAOP_STOP); + } + + buf = chan->curr; + if (buf == NULL) + buf = chan->next; + + chan->curr = chan->next = chan->end = NULL; + + if (buf != NULL) { + for ( ; buf != NULL; buf = next) { + next = buf->next; + + pr_debug("%s: free buffer %p, next %p\n", + __FUNCTION__, buf, buf->next); + + s3c2410_dma_buffdone(chan, buf, S3C2410_RES_ABORT); + s3c2410_dma_freebuf(buf); + } + } + + local_irq_restore(flags); + + return 0; +} + + +int +s3c2410_dma_ctrl(dmach_t channel, s3c2410_chan_op_t op) +{ + s3c2410_dma_chan_t *chan = &s3c2410_chans[channel]; + + check_channel(channel); + + switch (op) { + case S3C2410_DMAOP_START: + return s3c2410_dma_start(chan); + + case S3C2410_DMAOP_STOP: + return s3c2410_dma_dostop(chan); + + case S3C2410_DMAOP_PAUSE: + return -ENOENT; + + case S3C2410_DMAOP_RESUME: + return -ENOENT; + + case S3C2410_DMAOP_FLUSH: + return s3c2410_dma_flush(chan); + + case S3C2410_DMAOP_TIMEOUT: + return 0; + + } + + return -ENOENT; /* unknown, don't bother */ +} + +EXPORT_SYMBOL(s3c2410_dma_ctrl); + +/* DMA configuration for each channel + * + * DISRCC -> source of the DMA (AHB,APB) + * DISRC -> source address of the DMA + * DIDSTC -> destination of the DMA (AHB,APD) + * DIDST -> destination address of the DMA +*/ + +/* s3c2410_dma_config + * + * xfersize: size of unit in bytes (1,2,4) + * dcon: base value of the DCONx register +*/ + +int s3c2410_dma_config(dmach_t channel, + int xferunit, + int dcon) +{ + s3c2410_dma_chan_t *chan = &s3c2410_chans[channel]; + + pr_debug("%s: chan=%d, xfer_unit=%d, dcon=%08x\n", + __FUNCTION__, channel, xferunit, dcon); + + check_channel(channel); + + switch (xferunit) { + case 1: + dcon |= S3C2410_DCON_BYTE; + break; + + case 2: + dcon |= S3C2410_DCON_HALFWORD; + break; + + case 4: + dcon |= S3C2410_DCON_WORD; + break; + + default: + pr_debug("%s: bad transfer size %d\n", __FUNCTION__, xferunit); + return -EINVAL; + } + + dcon |= S3C2410_DCON_HWTRIG; + dcon |= S3C2410_DCON_INTREQ; + + pr_debug("%s: dcon now %08x\n", __FUNCTION__, dcon); + + chan->dcon = dcon; + chan->xfer_unit = xferunit; + + return 0; +} + +EXPORT_SYMBOL(s3c2410_dma_config); + +int s3c2410_dma_setflags(dmach_t channel, unsigned int flags) +{ + s3c2410_dma_chan_t *chan = &s3c2410_chans[channel]; + + check_channel(channel); + + pr_debug("%s: chan=%p, flags=%08x\n", __FUNCTION__, chan, flags); + + chan->flags = flags; + + return 0; +} + +EXPORT_SYMBOL(s3c2410_dma_setflags); + + +/* do we need to protect the settings of the fields from + * irq? +*/ + +int s3c2410_dma_set_opfn(dmach_t channel, s3c2410_dma_opfn_t rtn) +{ + s3c2410_dma_chan_t *chan = &s3c2410_chans[channel]; + + check_channel(channel); + + pr_debug("%s: chan=%p, op rtn=%p\n", __FUNCTION__, chan, rtn); + + chan->op_fn = rtn; + + return 0; +} + +EXPORT_SYMBOL(s3c2410_dma_set_opfn); + +int s3c2410_dma_set_buffdone_fn(dmach_t channel, s3c2410_dma_cbfn_t rtn) +{ + s3c2410_dma_chan_t *chan = &s3c2410_chans[channel]; + + check_channel(channel); + + pr_debug("%s: chan=%p, callback rtn=%p\n", __FUNCTION__, chan, rtn); + + chan->callback_fn = rtn; + + return 0; +} + +EXPORT_SYMBOL(s3c2410_dma_set_buffdone_fn); + +/* s3c2410_dma_devconfig + * + * configure the dma source/destination hardware type and address + * + * source: S3C2410_DMASRC_HW: source is hardware + * S3C2410_DMASRC_MEM: source is memory + * + * hwcfg: the value for xxxSTCn register, + * bit 0: 0=increment pointer, 1=leave pointer + * bit 1: 0=soucre is AHB, 1=soucre is APB + * + * devaddr: physical address of the source +*/ + +int s3c2410_dma_devconfig(int channel, + s3c2410_dmasrc_t source, + int hwcfg, + unsigned long devaddr) +{ + s3c2410_dma_chan_t *chan = &s3c2410_chans[channel]; + + check_channel(channel); + + pr_debug("%s: source=%d, hwcfg=%08x, devaddr=%08lx\n", + __FUNCTION__, (int)source, hwcfg, devaddr); + + chan->source = source; + chan->dev_addr = devaddr; + + switch (source) { + case S3C2410_DMASRC_HW: + /* source is hardware */ + pr_debug("%s: hw source, devaddr=%08lx, hwcfg=%d\n", + __FUNCTION__, devaddr, hwcfg); + dma_wrreg(chan, S3C2410_DMA_DISRCC, hwcfg & 3); + dma_wrreg(chan, S3C2410_DMA_DISRC, devaddr); + dma_wrreg(chan, S3C2410_DMA_DIDSTC, (0<<1) | (0<<0)); + + chan->addr_reg = dma_regaddr(chan, S3C2410_DMA_DIDST); + return 0; + + case S3C2410_DMASRC_MEM: + /* source is memory */ + pr_debug( "%s: mem source, devaddr=%08lx, hwcfg=%d\n", + __FUNCTION__, devaddr, hwcfg); + dma_wrreg(chan, S3C2410_DMA_DISRCC, (0<<1) | (0<<0)); + dma_wrreg(chan, S3C2410_DMA_DIDST, devaddr); + dma_wrreg(chan, S3C2410_DMA_DIDSTC, hwcfg & 3); + + chan->addr_reg = dma_regaddr(chan, S3C2410_DMA_DISRC); + return 0; + } + + printk(KERN_ERR "dma%d: invalid source type (%d)\n", channel, source); + return -EINVAL; +} + +EXPORT_SYMBOL(s3c2410_dma_devconfig); + +/* s3c2410_dma_getposition + * + * returns the current transfer points for the dma source and destination +*/ + +int s3c2410_dma_getposition(dmach_t channel, dma_addr_t *src, dma_addr_t *dst) +{ + s3c2410_dma_chan_t *chan = &s3c2410_chans[channel]; + + check_channel(channel); + + if (src != NULL) + *src = dma_rdreg(chan, S3C2410_DMA_DCSRC); + + if (dst != NULL) + *dst = dma_rdreg(chan, S3C2410_DMA_DCDST); + + return 0; +} + +EXPORT_SYMBOL(s3c2410_dma_getposition); + + +/* system device class */ + +#ifdef CONFIG_PM + +static int s3c2410_dma_suspend(struct sys_device *dev, pm_message_t state) +{ + s3c2410_dma_chan_t *cp = container_of(dev, s3c2410_dma_chan_t, dev); + + printk(KERN_DEBUG "suspending dma channel %d\n", cp->number); + + if (dma_rdreg(cp, S3C2410_DMA_DMASKTRIG) & S3C2410_DMASKTRIG_ON) { + /* the dma channel is still working, which is probably + * a bad thing to do over suspend/resume. We stop the + * channel and assume that the client is either going to + * retry after resume, or that it is broken. + */ + + printk(KERN_INFO "dma: stopping channel %d due to suspend\n", + cp->number); + + s3c2410_dma_dostop(cp); + } + + return 0; +} + +static int s3c2410_dma_resume(struct sys_device *dev) +{ + return 0; +} + +#else +#define s3c2410_dma_suspend NULL +#define s3c2410_dma_resume NULL +#endif /* CONFIG_PM */ + +static struct sysdev_class dma_sysclass = { + set_kset_name("s3c24xx-dma"), + .suspend = s3c2410_dma_suspend, + .resume = s3c2410_dma_resume, +}; + +/* kmem cache implementation */ + +static void s3c2410_dma_cache_ctor(void *p, kmem_cache_t *c, unsigned long f) +{ + memset(p, 0, sizeof(s3c2410_dma_buf_t)); +} + + +/* initialisation code */ + +static int __init s3c2410_init_dma(void) +{ + s3c2410_dma_chan_t *cp; + int channel; + int ret; + + printk("S3C2410 DMA Driver, (c) 2003-2004 Simtec Electronics\n"); + + dma_base = ioremap(S3C2410_PA_DMA, 0x200); + if (dma_base == NULL) { + printk(KERN_ERR "dma failed to remap register block\n"); + return -ENOMEM; + } + + ret = sysdev_class_register(&dma_sysclass); + if (ret != 0) { + printk(KERN_ERR "dma sysclass registration failed\n"); + goto err; + } + + dma_kmem = kmem_cache_create("dma_desc", sizeof(s3c2410_dma_buf_t), 0, + SLAB_HWCACHE_ALIGN, + s3c2410_dma_cache_ctor, NULL); + + if (dma_kmem == NULL) { + printk(KERN_ERR "dma failed to make kmem cache\n"); + ret = -ENOMEM; + goto err; + } + + for (channel = 0; channel < S3C2410_DMA_CHANNELS; channel++) { + cp = &s3c2410_chans[channel]; + + memset(cp, 0, sizeof(s3c2410_dma_chan_t)); + + /* dma channel irqs are in order.. */ + cp->number = channel; + cp->irq = channel + IRQ_DMA0; + cp->regs = dma_base + (channel*0x40); + + /* point current stats somewhere */ + cp->stats = &cp->stats_store; + cp->stats_store.timeout_shortest = LONG_MAX; + + /* basic channel configuration */ + + cp->load_timeout = 1<<18; + + /* register system device */ + + cp->dev.cls = &dma_sysclass; + cp->dev.id = channel; + ret = sysdev_register(&cp->dev); + + printk("DMA channel %d at %p, irq %d\n", + cp->number, cp->regs, cp->irq); + } + + return 0; + + err: + kmem_cache_destroy(dma_kmem); + iounmap(dma_base); + dma_base = NULL; + return ret; +} + +__initcall(s3c2410_init_dma); |