diff options
Diffstat (limited to 'arch/arm/plat-s3c24xx/dma.c')
| -rw-r--r-- | arch/arm/plat-s3c24xx/dma.c | 1499 |
1 files changed, 1499 insertions, 0 deletions
diff --git a/arch/arm/plat-s3c24xx/dma.c b/arch/arm/plat-s3c24xx/dma.c new file mode 100644 index 00000000000..4540a806f52 --- /dev/null +++ b/arch/arm/plat-s3c24xx/dma.c @@ -0,0 +1,1499 @@ +/* linux/arch/arm/plat-s3c24xx/dma.c + * + * Copyright (c) 2003-2005,2006 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + * + * S3C2410 DMA core + * + * http://armlinux.simtec.co.uk/ + * + * 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. +*/ + + +#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> + +#include <asm/plat-s3c24xx/dma.h> + +/* io map for dma */ +static void __iomem *dma_base; +static struct kmem_cache *dma_kmem; + +static int dma_channels; + +struct s3c24xx_dma_selection dma_sel; + +/* dma channel state information */ +struct s3c2410_dma_chan 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(struct s3c2410_dma_chan *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(struct s3c2410_dma_chan *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_dumpregs(const char *fname, int line, struct s3c2410_dma_chan *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, struct s3c2410_dma_chan *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_dumpregs(fname, line, chan, &state); +} + +static void +dmadbg_showregs(const char *fname, int line, struct s3c2410_dma_chan *chan) +{ + struct s3c2410_dma_regstate state; + + dmadbg_capture(chan, &state); + dmadbg_dumpregs(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 */ + +static struct s3c2410_dma_chan *dma_chan_map[DMACH_MAX]; + +/* lookup_dma_channel + * + * change the dma channel number given into a real dma channel id +*/ + +static struct s3c2410_dma_chan *lookup_dma_channel(unsigned int channel) +{ + if (channel & DMACH_LOW_LEVEL) + return &s3c2410_chans[channel & ~DMACH_LOW_LEVEL]; + else + return dma_chan_map[channel]; +} + +/* s3c2410_dma_stats_timeout + * + * Update DMA stats from timeout info +*/ + +static void +s3c2410_dma_stats_timeout(struct s3c2410_dma_stats *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(struct s3c2410_dma_chan *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(struct s3c2410_dma_chan *chan, + struct s3c2410_dma_buf *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; + } + + if ((buf->data & 0xf0000000) != 0x30000000) { + dmawarn("dmaload: buffer is %p\n", (void *)buf->data); + } + + 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(struct s3c2410_dma_chan *chan, enum s3c2410_chan_op 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(struct s3c2410_dma_chan *chan, struct s3c2410_dma_buf *buf, + enum s3c2410_dma_buffresult result) +{ +#if 0 + pr_debug("callback_fn=%p, buf=%p, id=%p, size=%d, result=%d\n", + chan->callback_fn, buf, buf->id, buf->size, result); +#endif + + 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(struct s3c2410_dma_chan *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("dma%d: %08lx to DMASKTRIG\n", chan->number, 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); + + /* if we've only loaded one buffer onto the channel, then chec + * to see if we have another, and if so, try and load it so when + * the first buffer is finished, the new one will be loaded onto + * the channel */ + + if (chan->next != NULL) { + if (chan->load_state == S3C2410_DMALOAD_1LOADED) { + + if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { + pr_debug("%s: buff not yet loaded, no more todo\n", + __FUNCTION__); + } else { + chan->load_state = S3C2410_DMALOAD_1RUNNING; + s3c2410_dma_loadbuffer(chan, chan->next); + } + + } else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) { + s3c2410_dma_loadbuffer(chan, chan->next); + } + } + + + 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(struct s3c2410_dma_chan *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) +{ + struct s3c2410_dma_chan *chan = lookup_dma_channel(channel); + struct s3c2410_dma_buf *buf; + unsigned long flags; + + if (chan == NULL) + return -EINVAL; + + 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 (%ld alloc)\n", + __FUNCTION__, (long)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(struct s3c2410_dma_buf *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(struct s3c2410_dma_chan *chan) +{ +#if 0 + pr_debug("dma%d: s3c2410_dma_lastxfer: load_state %d\n", + chan->number, chan->load_state); +#endif + + 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 (%s)\n", + chan->number, __FUNCTION__); + return; + } + break; + + case S3C2410_DMALOAD_1LOADED_1RUNNING: + /* I belive in this case we do not have anything to do + * until the next buffer comes along, and we turn off the + * reload */ + return; + + default: + pr_debug("dma%d: lastxfer: unhandled load_state %d with no next\n", + 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 s3c2410_dma_chan *chan = (struct s3c2410_dma_chan *)devpw; + struct s3c2410_dma_buf *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 { + } + + /* only reload if the channel is still running... our buffer done + * routine may have altered the state by requesting the dma channel + * to stop or shutdown... */ + + /* todo: check that when the channel is shut-down from inside this + * function, we cope with unsetting reload, etc */ + + if (chan->next != NULL && chan->state != S3C2410_DMA_IDLE) { + 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 (%s)\n", + chan->number, __FUNCTION__); + 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 | DMACH_LOW_LEVEL, + S3C2410_DMAOP_STOP); + } + } + + no_load: + return IRQ_HANDLED; +} + +static struct s3c2410_dma_chan *s3c2410_dma_map_channel(int channel); + +/* s3c2410_request_dma + * + * get control of an dma channel +*/ + +int s3c2410_dma_request(unsigned int channel, + struct s3c2410_dma_client *client, + void *dev) +{ + struct s3c2410_dma_chan *chan; + unsigned long flags; + int err; + + pr_debug("dma%d: s3c2410_request_dma: client=%s, dev=%p\n", + channel, client->name, dev); + + local_irq_save(flags); + + chan = s3c2410_dma_map_channel(channel); + if (chan == NULL) { + local_irq_restore(flags); + return -EBUSY; + } + + dbg_showchan(chan); + + chan->client = client; + chan->in_use = 1; + + if (!chan->irq_claimed) { + pr_debug("dma%d: %s : requesting irq %d\n", + channel, __FUNCTION__, chan->irq); + + chan->irq_claimed = 1; + local_irq_restore(flags); + + err = request_irq(chan->irq, s3c2410_dma_irq, IRQF_DISABLED, + client->name, (void *)chan); + + local_irq_save(flags); + + if (err) { + chan->in_use = 0; + chan->irq_claimed = 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_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, struct s3c2410_dma_client *client) +{ + struct s3c2410_dma_chan *chan = lookup_dma_channel(channel); + unsigned long flags; + + if (chan == NULL) + return -EINVAL; + + 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; + + if (chan->irq_claimed) + free_irq(chan->irq, (void *)chan); + + chan->irq_claimed = 0; + + if (!(channel & DMACH_LOW_LEVEL)) + dma_chan_map[channel] = NULL; + + local_irq_restore(flags); + + return 0; +} + +EXPORT_SYMBOL(s3c2410_dma_free); + +static int s3c2410_dma_dostop(struct s3c2410_dma_chan *chan) +{ + unsigned long flags; + unsigned long tmp; + + 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; + //tmp &= ~S3C2410_DMASKTRIG_ON; + 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 + + /* should stop do this, or should we wait for flush? */ + chan->state = S3C2410_DMA_IDLE; + chan->load_state = S3C2410_DMALOAD_NONE; + + local_irq_restore(flags); + + return 0; +} + +void s3c2410_dma_waitforstop(struct s3c2410_dma_chan *chan) +{ + unsigned long tmp; + unsigned int timeout = 0x10000; + + while (timeout-- > 0) { + tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); + + if (!(tmp & S3C2410_DMASKTRIG_ON)) + return; + } + + pr_debug("dma%d: failed to stop?\n", chan->number); +} + + +/* s3c2410_dma_flush + * + * stop the channel, and remove all current and pending transfers +*/ + +static int s3c2410_dma_flush(struct s3c2410_dma_chan *chan) +{ + struct s3c2410_dma_buf *buf, *next; + unsigned long flags; + + pr_debug("%s: chan %p (%d)\n", __FUNCTION__, chan, chan->number); + + dbg_showchan(chan); + + 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); + } + } + + dbg_showregs(chan); + + s3c2410_dma_waitforstop(chan); + +#if 0 + /* should also clear interrupts, according to WinCE BSP */ + { + unsigned long tmp; + + tmp = dma_rdreg(chan, S3C2410_DMA_DCON); + tmp |= S3C2410_DCON_NORELOAD; + dma_wrreg(chan, S3C2410_DMA_DCON, tmp); + } +#endif + + dbg_showregs(chan); + + local_irq_restore(flags); + + return 0; +} + +int +s3c2410_dma_started(struct s3c2410_dma_chan *chan) +{ + unsigned long flags; + + local_irq_save(flags); + + dbg_showchan(chan); + + /* if we've only loaded one buffer onto the channel, then chec + * to see if we have another, and if so, try and load it so when + * the first buffer is finished, the new one will be loaded onto + * the channel */ + + if (chan->next != NULL) { + if (chan->load_state == S3C2410_DMALOAD_1LOADED) { + + if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { + pr_debug("%s: buff not yet loaded, no more todo\n", + __FUNCTION__); + } else { + chan->load_state = S3C2410_DMALOAD_1RUNNING; + s3c2410_dma_loadbuffer(chan, chan->next); + } + + } else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) { + s3c2410_dma_loadbuffer(chan, chan->next); + } + } + + + local_irq_restore(flags); + + return 0; + +} + +int +s3c2410_dma_ctrl(dmach_t channel, enum s3c2410_chan_op op) +{ + struct s3c2410_dma_chan *chan = lookup_dma_channel(channel); + + if (chan == NULL) + return -EINVAL; + + switch (op) { + case S3C2410_DMAOP_START: + return s3c2410_dma_start(chan); + + case S3C2410_DMAOP_STOP: + return s3c2410_dma_dostop(chan); + + case S3C2410_DMAOP_PAUSE: + case S3C2410_DMAOP_RESUME: + return -ENOENT; + + case S3C2410_DMAOP_FLUSH: + return s3c2410_dma_flush(chan); + + case S3C2410_DMAOP_STARTED: + return s3c2410_dma_started(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) +{ + struct s3c2410_dma_chan *chan = lookup_dma_channel(channel); + + pr_debug("%s: chan=%d, xfer_unit=%d, dcon=%08x\n", + __FUNCTION__, channel, xferunit, dcon); + + if (chan == NULL) + return -EINVAL; + + pr_debug("%s: Initial dcon is %08x\n", __FUNCTION__, dcon); + + dcon |= chan->dcon & dma_sel.dcon_mask; + + pr_debug("%s: New dcon is %08x\n", __FUNCTION__, dcon); + + 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) +{ + struct s3c2410_dma_chan *chan = lookup_dma_channel(channel); + + if (chan == NULL) + return -EINVAL; + + 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) +{ + struct s3c2410_dma_chan *chan = lookup_dma_channel(channel); + + if (chan == NULL) + return -EINVAL; + + 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) +{ + struct s3c2410_dma_chan *chan = lookup_dma_channel(channel); + + if (chan == NULL) + return -EINVAL; + + 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, + enum s3c2410_dmasrc source, + int hwcfg, + unsigned long devaddr) +{ + struct s3c2410_dma_chan *chan = lookup_dma_channel(channel); + + if (chan == NULL) + return -EINVAL; + + 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) +{ + struct s3c2410_dma_chan *chan = lookup_dma_channel(channel); + + if (chan == NULL) + return -EINVAL; + + 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) +{ + struct s3c2410_dma_chan *cp = container_of(dev, struct s3c2410_dma_chan, 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 */ + +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, struct kmem_cache *c, unsigned long f) +{ + memset(p, 0, sizeof(struct s3c2410_dma_buf)); +} + +/* initialisation code */ + +int __init s3c24xx_dma_sysclass_init(void) +{ + int ret = sysdev_class_register(&dma_sysclass); + + if (ret != 0) + printk(KERN_ERR "dma sysclass registration failed\n"); + + return ret; +} + +core_initcall(s3c24xx_dma_sysclass_init); + +int __init s3c24xx_dma_sysdev_register(void) +{ + struct s3c2410_dma_chan *cp = s3c2410_chans; + int channel, ret; + + for (channel = 0; channel < dma_channels; cp++, channel++) { + cp->dev.cls = &dma_sysclass; + cp->dev.id = channel; + ret = sysdev_register(&cp->dev); + + if (ret) { + printk(KERN_ERR "error registering dev for dma %d\n", + channel); + return ret; + } + } + + return 0; +} + +late_initcall(s3c24xx_dma_sysdev_register); + +int __init s3c24xx_dma_init(unsigned int channels, unsigned int irq, + unsigned int stride) +{ + struct s3c2410_dma_chan *cp; + int channel; + int ret; + + printk("S3C24XX DMA Driver, (c) 2003-2004,2006 Simtec Electronics\n"); + + dma_channels = channels; + + dma_base = ioremap(S3C24XX_PA_DMA, stride * channels); + if (dma_base == NULL) { + printk(KERN_ERR "dma failed to remap register block\n"); + return -ENOMEM; + } + + dma_kmem = kmem_cache_create("dma_desc", + sizeof(struct s3c2410_dma_buf), 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 < channels; channel++) { + cp = &s3c2410_chans[channel]; + + memset(cp, 0, sizeof(struct s3c2410_dma_chan)); + + /* dma channel irqs are in order.. */ + cp->number = channel; + cp->irq = channel + irq; + cp->regs = dma_base + (channel * stride); + + /* point current stats somewhere */ + cp->stats = &cp->stats_store; + cp->stats_store.timeout_shortest = LONG_MAX; + + /* basic channel configuration */ + + cp->load_timeout = 1<<18; + + 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; +} + +int s3c2410_dma_init(void) +{ + return s3c24xx_dma_init(4, IRQ_DMA0, 0x40); +} + +static inline int is_channel_valid(unsigned int channel) +{ + return (channel & DMA_CH_VALID); +} + +static struct s3c24xx_dma_order *dma_order; + + +/* s3c2410_dma_map_channel() + * + * turn the virtual channel number into a real, and un-used hardware + * channel. + * + * first, try the dma ordering given to us by either the relevant + * dma code, or the board. Then just find the first usable free + * channel +*/ + +struct s3c2410_dma_chan *s3c2410_dma_map_channel(int channel) +{ + struct s3c24xx_dma_order_ch *ord = NULL; + struct s3c24xx_dma_map *ch_map; + struct s3c2410_dma_chan *dmach; + int ch; + + if (dma_sel.map == NULL || channel > dma_sel.map_size) + return NULL; + + ch_map = dma_sel.map + channel; + + /* first, try the board mapping */ + + if (dma_order) { + ord = &dma_order->channels[channel]; + + for (ch = 0; ch < dma_channels; ch++) { + if (!is_channel_valid(ord->list[ch])) + continue; + + if (s3c2410_chans[ord->list[ch]].in_use == 0) { + ch = ord->list[ch] & ~DMA_CH_VALID; + goto found; + } + } + + if (ord->flags & DMA_CH_NEVER) + return NULL; + } + + /* second, search the channel map for first free */ + + for (ch = 0; ch < dma_channels; ch++) { + if (!is_channel_valid(ch_map->channels[ch])) + continue; + + if (s3c2410_chans[ch].in_use == 0) { + printk("mapped channel %d to %d\n", channel, ch); + break; + } + } + + if (ch >= dma_channels) + return NULL; + + /* update our channel mapping */ + + found: + dmach = &s3c2410_chans[ch]; + dma_chan_map[channel] = dmach; + + /* select the channel */ + + (dma_sel.select)(dmach, ch_map); + + return dmach; +} + +static int s3c24xx_dma_check_entry(struct s3c24xx_dma_map *map, int ch) +{ + return 0; +} + +int __init s3c24xx_dma_init_map(struct s3c24xx_dma_selection *sel) +{ + struct s3c24xx_dma_map *nmap; + size_t map_sz = sizeof(*nmap) * sel->map_size; + int ptr; + + nmap = kmalloc(map_sz, GFP_KERNEL); + if (nmap == NULL) + return -ENOMEM; + + memcpy(nmap, sel->map, map_sz); + memcpy(&dma_sel, sel, sizeof(*sel)); + + dma_sel.map = nmap; + + for (ptr = 0; ptr < sel->map_size; ptr++) + s3c24xx_dma_check_entry(nmap+ptr, ptr); + + return 0; +} + +int __init s3c24xx_dma_order_set(struct s3c24xx_dma_order *ord) +{ + struct s3c24xx_dma_order *nord = dma_order; + + if (nord == NULL) + nord = kmalloc(sizeof(struct s3c24xx_dma_order), GFP_KERNEL); + + if (nord == NULL) { + printk(KERN_ERR "no memory to store dma channel order\n"); + return -ENOMEM; + } + + dma_order = nord; + memcpy(nord, ord, sizeof(struct s3c24xx_dma_order)); + return 0; +} |