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linux_dsm_epyc7002/arch/arm/plat-s3c24xx/dma.c
Julia Lawall 60e5c1b5ec ARM: S3C24XX: arch/arm/plat-s3c24xx: Move dereference after NULL test 
If the NULL test on buf is needed, then the dereference should be after the
NULL test.

A simplified version of the semantic match that detects this problem is as
follows (http://coccinelle.lip6.fr/):

// <smpl>
@match exists@
expression x, E;
identifier fld;
@@

* x->fld
  ... when != \(x = E\|&x\)
* x == NULL
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-10-28 18:25:57 +00:00

1491 lines
33 KiB
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/* 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/io.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <mach/hardware.h>
#include <mach/dma.h>
#include <mach/map.h>
#include <plat/dma-plat.h>
#include <plat/regs-dma.h>
/* io map for dma */
static void __iomem *dma_base;
static struct kmem_cache *dma_kmem;
static int dma_channels;
static struct s3c24xx_dma_selection dma_sel;
/* 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(__func__, __LINE__, (chan))
#define dbg_showchan(chan) dmadbg_showchan(__func__, __LINE__, (chan))
#else
#define dbg_showregs(chan) do { } while(0)
#define dbg_showchan(chan) do { } while(0)
#endif /* CONFIG_S3C2410_DMA_DEBUG */
/* 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;
if (buf == NULL) {
dmawarn("buffer is NULL\n");
return -EINVAL;
}
pr_debug("s3c2410_chan_loadbuffer: loading buff %p (0x%08lx,0x%06x)\n",
buf, (unsigned long)buf->data, buf->size);
/* 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",
__func__);
} 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 = s3c_dma_lookup_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",
__func__, 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",
__func__, (long)sizeof(*buf));
return -ENOMEM;
}
//pr_debug("%s: new buffer %p\n", __func__, 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",
__func__, 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, __func__, buf);
if (chan->end == NULL)
pr_debug("dma%d: %s: %p not empty, and chan->end==NULL?\n",
chan->number, __func__, 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 | DMACH_LOW_LEVEL,
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, __func__);
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, __func__, 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, __func__);
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, __func__, 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", __func__, chan);
return chan->number | DMACH_LOW_LEVEL;
}
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(unsigned int channel, struct s3c2410_dma_client *client)
{
struct s3c2410_dma_chan *chan = s3c_dma_lookup_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",
__func__, 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))
s3c_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", __func__);
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;
}
static 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", __func__, chan, chan->number);
dbg_showchan(chan);
local_irq_save(flags);
if (chan->state != S3C2410_DMA_IDLE) {
pr_debug("%s: stopping channel...\n", __func__ );
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",
__func__, 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;
}
static 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",
__func__);
} 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(unsigned int channel, enum s3c2410_chan_op op)
{
struct s3c2410_dma_chan *chan = s3c_dma_lookup_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)
*/
int s3c2410_dma_config(unsigned int channel,
int xferunit)
{
struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
unsigned int dcon;
pr_debug("%s: chan=%d, xfer_unit=%d, dcon=%08x\n",
__func__, channel, xferunit, dcon);
if (chan == NULL)
return -EINVAL;
pr_debug("%s: Initial dcon is %08x\n", __func__, dcon);
dcon = chan->dcon & dma_sel.dcon_mask;
pr_debug("%s: New dcon is %08x\n", __func__, dcon);
switch (chan->req_ch) {
case DMACH_I2S_IN:
case DMACH_I2S_OUT:
case DMACH_PCM_IN:
case DMACH_PCM_OUT:
case DMACH_MIC_IN:
default:
dcon |= S3C2410_DCON_HANDSHAKE;
dcon |= S3C2410_DCON_SYNC_PCLK;
break;
case DMACH_SDI:
/* note, ensure if need HANDSHAKE or not */
dcon |= S3C2410_DCON_SYNC_PCLK;
break;
case DMACH_XD0:
case DMACH_XD1:
dcon |= S3C2410_DCON_HANDSHAKE;
dcon |= S3C2410_DCON_SYNC_HCLK;
break;
}
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", __func__, xferunit);
return -EINVAL;
}
dcon |= S3C2410_DCON_HWTRIG;
dcon |= S3C2410_DCON_INTREQ;
pr_debug("%s: dcon now %08x\n", __func__, dcon);
chan->dcon = dcon;
chan->xfer_unit = xferunit;
return 0;
}
EXPORT_SYMBOL(s3c2410_dma_config);
/* 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
*
* devaddr: physical address of the source
*/
int s3c2410_dma_devconfig(int channel,
enum s3c2410_dmasrc source,
unsigned long devaddr)
{
struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
unsigned int hwcfg;
if (chan == NULL)
return -EINVAL;
pr_debug("%s: source=%d, devaddr=%08lx\n",
__func__, (int)source, devaddr);
chan->source = source;
chan->dev_addr = devaddr;
switch (chan->req_ch) {
case DMACH_XD0:
case DMACH_XD1:
hwcfg = 0; /* AHB */
break;
default:
hwcfg = S3C2410_DISRCC_APB;
}
/* always assume our peripheral desintation is a fixed
* address in memory. */
hwcfg |= S3C2410_DISRCC_INC;
switch (source) {
case S3C2410_DMASRC_HW:
/* source is hardware */
pr_debug("%s: hw source, devaddr=%08lx, hwcfg=%d\n",
__func__, 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);
break;
case S3C2410_DMASRC_MEM:
/* source is memory */
pr_debug("%s: mem source, devaddr=%08lx, hwcfg=%d\n",
__func__, 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);
break;
default:
printk(KERN_ERR "dma%d: invalid source type (%d)\n",
channel, source);
return -EINVAL;
}
if (dma_sel.direction != NULL)
(dma_sel.direction)(chan, chan->map, source);
return 0;
}
EXPORT_SYMBOL(s3c2410_dma_devconfig);
/* s3c2410_dma_getposition
*
* returns the current transfer points for the dma source and destination
*/
int s3c2410_dma_getposition(unsigned int channel, dma_addr_t *src, dma_addr_t *dst)
{
struct s3c2410_dma_chan *chan = s3c_dma_lookup_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);
static inline struct s3c2410_dma_chan *to_dma_chan(struct sys_device *dev)
{
return container_of(dev, struct s3c2410_dma_chan, dev);
}
/* system device class */
#ifdef CONFIG_PM
static int s3c2410_dma_suspend(struct sys_device *dev, pm_message_t state)
{
struct s3c2410_dma_chan *cp = to_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)
{
struct s3c2410_dma_chan *cp = to_dma_chan(dev);
unsigned int no = cp->number | DMACH_LOW_LEVEL;
/* restore channel's hardware configuration */
if (!cp->in_use)
return 0;
printk(KERN_INFO "dma%d: restoring configuration\n", cp->number);
s3c2410_dma_config(no, cp->xfer_unit);
s3c2410_dma_devconfig(no, cp->source, cp->dev_addr);
/* re-select the dma source for this channel */
if (cp->map != NULL)
dma_sel.select(cp, cp->map);
return 0;
}
#else
#define s3c2410_dma_suspend NULL
#define s3c2410_dma_resume NULL
#endif /* CONFIG_PM */
struct sysdev_class dma_sysclass = {
.name = "s3c24xx-dma",
.suspend = s3c2410_dma_suspend,
.resume = s3c2410_dma_resume,
};
/* kmem cache implementation */
static void s3c2410_dma_cache_ctor(void *p)
{
memset(p, 0, sizeof(struct s3c2410_dma_buf));
}
/* initialisation code */
static 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);
static 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);
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 __init 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
*/
static 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];
dmach->map = ch_map;
dmach->req_ch = channel;
s3c_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;
}
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