- 根目录:
- arch
- arm
- mach-s3c64xx
- dma.c
/* linux/arch/arm/plat-s3c64xx/dma.c
*
* Copyright 2009 Openmoko, Inc.
* Copyright 2009 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
* http://armlinux.simtec.co.uk/
*
* S3C64XX DMA core
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/dmapool.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/amba/pl080.h>
#include <mach/dma.h>
#include <mach/map.h>
#include <mach/irqs.h>
#include "regs-sys.h"
/* dma channel state information */
struct s3c64xx_dmac {
struct device dev;
struct clk *clk;
void __iomem *regs;
struct s3c2410_dma_chan *channels;
enum dma_ch chanbase;
};
/* pool to provide LLI buffers */
static struct dma_pool *dma_pool;
/* Debug configuration and code */
static unsigned char debug_show_buffs = 0;
static void dbg_showchan(struct s3c2410_dma_chan *chan)
{
pr_debug("DMA%d: %08x->%08x L %08x C %08x,%08x S %08x\n",
chan->number,
readl(chan->regs + PL080_CH_SRC_ADDR),
readl(chan->regs + PL080_CH_DST_ADDR),
readl(chan->regs + PL080_CH_LLI),
readl(chan->regs + PL080_CH_CONTROL),
readl(chan->regs + PL080S_CH_CONTROL2),
readl(chan->regs + PL080S_CH_CONFIG));
}
static void show_lli(struct pl080s_lli *lli)
{
pr_debug("LLI[%p] %08x->%08x, NL %08x C %08x,%08x\n",
lli, lli->src_addr, lli->dst_addr, lli->next_lli,
lli->control0, lli->control1);
}
static void dbg_showbuffs(struct s3c2410_dma_chan *chan)
{
struct s3c64xx_dma_buff *ptr;
struct s3c64xx_dma_buff *end;
pr_debug("DMA%d: buffs next %p, curr %p, end %p\n",
chan->number, chan->next, chan->curr, chan->end);
ptr = chan->next;
end = chan->end;
if (debug_show_buffs) {
for (; ptr != NULL; ptr = ptr->next) {
pr_debug("DMA%d: %08x ",
chan->number, ptr->lli_dma);
show_lli(ptr->lli);
}
}
}
/* End of Debug */
static struct s3c2410_dma_chan *s3c64xx_dma_map_channel(unsigned int channel)
{
struct s3c2410_dma_chan *chan;
unsigned int start, offs;
start = 0;
if (channel >= DMACH_PCM1_TX)
start = 8;
for (offs = 0; offs < 8; offs++) {
chan = &s3c2410_chans[start + offs];
if (!chan->in_use)
goto found;
}
return NULL;
found:
s3c_dma_chan_map[channel] = chan;
return chan;
}
int s3c2410_dma_config(enum dma_ch channel, int xferunit)
{
struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
if (chan == NULL)
return -EINVAL;
switch (xferunit) {
case 1:
chan->hw_width = 0;
break;
case 2:
chan->hw_width = 1;
break;
case 4:
chan->hw_width = 2;
break;
default:
printk(KERN_ERR "%s: illegal width %d\n", __func__, xferunit);
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL(s3c2410_dma_config);
static void s3c64xx_dma_fill_lli(struct s3c2410_dma_chan *chan,
struct pl080s_lli *lli,
dma_addr_t data, int size)
{
dma_addr_t src, dst;
u32 control0, control1;
switch (chan->source) {
case DMA_FROM_DEVICE:
src = chan->dev_addr;
dst = data;
control0 = PL080_CONTROL_SRC_AHB2;
control0 |= PL080_CONTROL_DST_INCR;
break;
case DMA_TO_DEVICE:
src = data;
dst = chan->dev_addr;
control0 = PL080_CONTROL_DST_AHB2;
control0 |= PL080_CONTROL_SRC_INCR;
break;
default:
BUG();
}
/* note, we do not currently setup any of the burst controls */
control1 = size >> chan->hw_width; /* size in no of xfers */
control0 |= PL080_CONTROL_PROT_SYS; /* always in priv. mode */
control0 |= PL080_CONTROL_TC_IRQ_EN; /* always fire IRQ */
control0 |= (u32)chan->hw_width << PL080_CONTROL_DWIDTH_SHIFT;
control0 |= (u32)chan->hw_width << PL080_CONTROL_SWIDTH_SHIFT;
lli->src_addr = src;
lli->dst_addr = dst;
lli->next_lli = 0;
lli->control0 = control0;
lli->control1 = control1;
}
static void s3c64xx_lli_to_regs(struct s3c2410_dma_chan *chan,
struct pl080s_lli *lli)
{
void __iomem *regs = chan->regs;
pr_debug("%s: LLI %p => regs\n", __func__, lli);
show_lli(lli);
writel(lli->src_addr, regs + PL080_CH_SRC_ADDR);
writel(lli->dst_addr, regs + PL080_CH_DST_ADDR);
writel(lli->next_lli, regs + PL080_CH_LLI);
writel(lli->control0, regs + PL080_CH_CONTROL);
writel(lli->control1, regs + PL080S_CH_CONTROL2);
}
static int s3c64xx_dma_start(struct s3c2410_dma_chan *chan)
{
struct s3c64xx_dmac *dmac = chan->dmac;
u32 config;
u32 bit = chan->bit;
dbg_showchan(chan);
pr_debug("%s: clearing interrupts\n", __func__);
/* clear interrupts */
writel(bit, dmac->regs + PL080_TC_CLEAR);
writel(bit, dmac->regs + PL080_ERR_CLEAR);
pr_debug("%s: starting channel\n", __func__);
config = readl(chan->regs + PL080S_CH_CONFIG);
config |= PL080_CONFIG_ENABLE;
config &= ~PL080_CONFIG_HALT;
pr_debug("%s: writing config %08x\n", __func__, config);
writel(config, chan->regs + PL080S_CH_CONFIG);
return 0;
}
static int s3c64xx_dma_stop(struct s3c2410_dma_chan *chan)
{
u32 config;
int timeout;
pr_debug("%s: stopping channel\n", __func__);
dbg_showchan(chan);
config = readl(chan->regs + PL080S_CH_CONFIG);
config |= PL080_CONFIG_HALT;
writel(config, chan->regs + PL080S_CH_CONFIG);
timeout = 1000;
do {
config = readl(chan->regs + PL080S_CH_CONFIG);
pr_debug("%s: %d - config %08x\n", __func__, timeout, config);
if (config & PL080_CONFIG_ACTIVE)
udelay(10);
else
break;
} while (--timeout > 0);
if (config & PL080_CONFIG_ACTIVE) {
printk(KERN_ERR "%s: channel still active\n", __func__);
return -EFAULT;
}
config = readl(chan->regs + PL080S_CH_CONFIG);
config &= ~PL080_CONFIG_ENABLE;
writel(config, chan->regs + PL080S_CH_CONFIG);
return 0;
}
static inline void s3c64xx_dma_bufffdone(struct s3c2410_dma_chan *chan,
struct s3c64xx_dma_buff *buf,
enum s3c2410_dma_buffresult result)
{
if (chan->callback_fn != NULL)
(chan->callback_fn)(chan, buf->pw, 0, result);
}
static void s3c64xx_dma_freebuff(struct s3c64xx_dma_buff *buff)
{
dma_pool_free(dma_pool, buff->lli, buff->lli_dma);
kfree(buff);
}
static int s3c64xx_dma_flush(struct s3c2410_dma_chan *chan)
{
struct s3c64xx_dma_buff *buff, *next;
u32 config;
dbg_showchan(chan);
pr_debug("%s: flushing channel\n", __func__);
config = readl(chan->regs + PL080S_CH_CONFIG);
config &= ~PL080_CONFIG_ENABLE;
writel(config, chan->regs + PL080S_CH_CONFIG);
/* dump all the buffers associated with this channel */
for (buff = chan->curr; buff != NULL; buff = next) {
next = buff->next;
pr_debug("%s: buff %p (next %p)\n", __func__, buff, buff->next);
s3c64xx_dma_bufffdone(chan, buff, S3C2410_RES_ABORT);
s3c64xx_dma_freebuff(buff);
}
chan->curr = chan->next = chan->end = NULL;
return 0;
}
int s3c2410_dma_ctrl(enum dma_ch channel, enum s3c2410_chan_op op)
{
struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
WARN_ON(!chan);
if (!chan)
return -EINVAL;
switch (op) {
case S3C2410_DMAOP_START:
return s3c64xx_dma_start(chan);
case S3C2410_DMAOP_STOP:
return s3c64xx_dma_stop(chan);
case S3C2410_DMAOP_FLUSH:
return s3c64xx_dma_flush(chan);
/* believe PAUSE/RESUME are no-ops */
case S3C2410_DMAOP_PAUSE:
case S3C2410_DMAOP_RESUME:
case S3C2410_DMAOP_STARTED:
case S3C2410_DMAOP_TIMEOUT:
return 0;
}
return -ENOENT;
}
EXPORT_SYMBOL(s3c2410_dma_ctrl);
/* s3c2410_dma_enque
*
*/
int s3c2410_dma_enqueue(enum dma_ch channel, void *id,
dma_addr_t data, int size)
{
struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
struct s3c64xx_dma_buff *next;
struct s3c64xx_dma_buff *buff;
struct pl080s_lli *lli;
unsigned long flags;
int ret;
WARN_ON(!chan);
if (!chan)
return -EINVAL;
buff = kzalloc(sizeof(struct s3c64xx_dma_buff), GFP_ATOMIC);
if (!buff) {
printk(KERN_ERR "%s: no memory for buffer\n", __func__);
return -ENOMEM;
}
lli = dma_pool_alloc(dma_pool, GFP_ATOMIC, &buff->lli_dma);
if (!lli) {
printk(KERN_ERR "%s: no memory for lli\n", __func__);
ret = -ENOMEM;
goto err_buff;
}
pr_debug("%s: buff %p, dp %08x lli (%p, %08x) %d\n",
__func__, buff, data, lli, (u32)buff->lli_dma, size);
buff->lli = lli;
buff->pw = id;
s3c64xx_dma_fill_lli(chan, lli, data, size);
local_irq_save(flags);
if ((next = chan->next) != NULL) {
struct s3c64xx_dma_buff *end = chan->end;
struct pl080s_lli *endlli = end->lli;
pr_debug("enquing onto channel\n");
end->next = buff;
endlli->next_lli = buff->lli_dma;
if (chan->flags & S3C2410_DMAF_CIRCULAR) {
struct s3c64xx_dma_buff *curr = chan->curr;
lli->next_lli = curr->lli_dma;
}
if (next == chan->curr) {
writel(buff->lli_dma, chan->regs + PL080_CH_LLI);
chan->next = buff;
}
show_lli(endlli);
chan->end = buff;
} else {
pr_debug("enquing onto empty channel\n");
chan->curr = buff;
chan->next = buff;
chan->end = buff;
s3c64xx_lli_to_regs(chan, lli);
}
local_irq_restore(flags);
show_lli(lli);
dbg_showchan(chan);
dbg_showbuffs(chan);
return 0;
err_buff:
kfree(buff);
return ret;
}
EXPORT_SYMBOL(s3c2410_dma_enqueue);
int s3c2410_dma_devconfig(enum dma_ch channel,
enum dma_data_direction source,
unsigned long devaddr)
{
struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
u32 peripheral;
u32 config = 0;
pr_debug("%s: channel %d, source %d, dev %08lx, chan %p\n",
__func__, channel, source, devaddr, chan);
WARN_ON(!chan);
if (!chan)
return -EINVAL;
peripheral = (chan->peripheral & 0xf);
chan->source = source;
chan->dev_addr = devaddr;
pr_debug("%s: peripheral %d\n", __func__, peripheral);
switch (source) {
case DMA_FROM_DEVICE:
config = 2 << PL080_CONFIG_FLOW_CONTROL_SHIFT;
config |= peripheral << PL080_CONFIG_SRC_SEL_SHIFT;
break;
case DMA_TO_DEVICE:
config = 1 << PL080_CONFIG_FLOW_CONTROL_SHIFT;
config |= peripheral << PL080_CONFIG_DST_SEL_SHIFT;
break;
default:
printk(KERN_ERR "%s: bad source\n", __func__);
return -EINVAL;
}
/* allow TC and ERR interrupts */
config |= PL080_CONFIG_TC_IRQ_MASK;
config |= PL080_CONFIG_ERR_IRQ_MASK;
pr_debug("%s: config %08x\n", __func__, config);
writel(config, chan->regs + PL080S_CH_CONFIG);
return 0;
}
EXPORT_SYMBOL(s3c2410_dma_devconfig);
int s3c2410_dma_getposition(enum dma_ch channel,
dma_addr_t *src, dma_addr_t *dst)
{
struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
WARN_ON(!chan);
if (!chan)
return -EINVAL;
if (src != NULL)
*src = readl(chan->regs + PL080_CH_SRC_ADDR);
if (dst != NULL)
*dst = readl(chan->regs + PL080_CH_DST_ADDR);
return 0;
}
EXPORT_SYMBOL(s3c2410_dma_getposition);
/* s3c2410_request_dma
*
* get control of an dma channel
*/
int s3c2410_dma_request(enum dma_ch channel,
struct s3c2410_dma_client *client,
void *dev)
{
struct s3c2410_dma_chan *chan;
unsigned long flags;
pr_debug("dma%d: s3c2410_request_dma: client=%s, dev=%p\n",
channel, client->name, dev);
local_irq_save(flags);
chan = s3c64xx_dma_map_channel(channel);
if (chan == NULL) {
local_irq_restore(flags);
return -EBUSY;
}
dbg_showchan(chan);
chan->client = client;
chan->in_use = 1;
chan->peripheral = channel;
chan->flags = 0;
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(enum dma_ch 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 */
chan->client = NULL;
chan->in_use = 0;
if (!(channel & DMACH_LOW_LEVEL))
s3c_dma_chan_map[channel] = NULL;
local_irq_restore(flags);
return 0;
}
EXPORT_SYMBOL(s3c2410_dma_free);
static irqreturn_t s3c64xx_dma_irq(int irq, void *pw)
{
struct s3c64xx_dmac *dmac = pw;
struct s3c2410_dma_chan *chan;
enum s3c2410_dma_buffresult res;
u32 tcstat, errstat;
u32 bit;
int offs;
tcstat = readl(dmac->regs + PL080_TC_STATUS);
errstat = readl(dmac->regs + PL080_ERR_STATUS);
for (offs = 0, bit = 1; offs < 8; offs++, bit <<= 1) {
struct s3c64xx_dma_buff *buff;
if (!(errstat & bit) && !(tcstat & bit))
continue;
chan = dmac->channels + offs;
res = S3C2410_RES_ERR;
if (tcstat & bit) {
writel(bit, dmac->regs + PL080_TC_CLEAR);
res = S3C2410_RES_OK;
}
if (errstat & bit)
writel(bit, dmac->regs + PL080_ERR_CLEAR);
/* 'next' points to the buffer that is next to the
* currently active buffer.
* For CIRCULAR queues, 'next' will be same as 'curr'
* when 'end' is the active buffer.
*/
buff = chan->curr;
while (buff && buff != chan->next
&& buff->next != chan->next)
buff = buff->next;
if (!buff)
BUG();
if (buff == chan->next)
buff = chan->end;
s3c64xx_dma_bufffdone(chan, buff, res);
/* Free the node and update curr, if non-circular queue */
if (!(chan->flags & S3C2410_DMAF_CIRCULAR)) {
chan->curr = buff->next;
s3c64xx_dma_freebuff(buff);
}
/* Update 'next' */
buff = chan->next;
if (chan->next == chan->end) {
chan->next = chan->curr;
if (!(chan->flags & S3C2410_DMAF_CIRCULAR))
chan->end = NULL;
} else {
chan->next = buff->next;
}
}
return IRQ_HANDLED;
}
static struct bus_type dma_subsys = {
.name = "s3c64xx-dma",
.dev_name = "s3c64xx-dma",
};
static int s3c64xx_dma_init1(int chno, enum dma_ch chbase,
int irq, unsigned int base)
{
struct s3c2410_dma_chan *chptr = &s3c2410_chans[chno];
struct s3c64xx_dmac *dmac;
char clkname[16];
void __iomem *regs;
void __iomem *regptr;
int err, ch;
dmac = kzalloc(sizeof(struct s3c64xx_dmac), GFP_KERNEL);
if (!dmac) {
printk(KERN_ERR "%s: failed to alloc mem\n", __func__);
return -ENOMEM;
}
dmac->dev.id = chno / 8;
dmac->dev.bus = &dma_subsys;
err = device_register(&dmac->dev);
if (err) {
printk(KERN_ERR "%s: failed to register device\n", __func__);
goto err_alloc;
}
regs = ioremap(base, 0x200);
if (!regs) {
printk(KERN_ERR "%s: failed to ioremap()\n", __func__);
err = -ENXIO;
goto err_dev;
}
snprintf(clkname, sizeof(clkname), "dma%d", dmac->dev.id);
dmac->clk = clk_get(NULL, clkname);
if (IS_ERR(dmac->clk)) {
printk(KERN_ERR "%s: failed to get clock %s\n", __func__, clkname);
err = PTR_ERR(dmac->clk);
goto err_map;
}
clk_enable(dmac->clk);
dmac->regs = regs;
dmac->chanbase = chbase;
dmac->channels = chptr;
err = request_irq(irq, s3c64xx_dma_irq, 0, "DMA", dmac);
if (err < 0) {
printk(KERN_ERR "%s: failed to get irq\n", __func__);
goto err_clk;
}
regptr = regs + PL080_Cx_BASE(0);
for (ch = 0; ch < 8; ch++, chptr++) {
pr_debug("%s: registering DMA %d (%p)\n",
__func__, chno + ch, regptr);
chptr->bit = 1 << ch;
chptr->number = chno + ch;
chptr->dmac = dmac;
chptr->regs = regptr;
regptr += PL080_Cx_STRIDE;
}
/* for the moment, permanently enable the controller */
writel(PL080_CONFIG_ENABLE, regs + PL080_CONFIG);
printk(KERN_INFO "PL080: IRQ %d, at %p, channels %d..%d\n",
irq, regs, chno, chno+8);
return 0;
err_clk:
clk_disable(dmac->clk);
clk_put(dmac->clk);
err_map:
iounmap(regs);
err_dev:
device_unregister(&dmac->dev);
err_alloc:
kfree(dmac);
return err;
}
static int __init s3c64xx_dma_init(void)
{
int ret;
printk(KERN_INFO "%s: Registering DMA channels\n", __func__);
dma_pool = dma_pool_create("DMA-LLI", NULL, sizeof(struct pl080s_lli), 16, 0);
if (!dma_pool) {
printk(KERN_ERR "%s: failed to create pool\n", __func__);
return -ENOMEM;
}
ret = subsys_system_register(&dma_subsys, NULL);
if (ret) {
printk(KERN_ERR "%s: failed to create subsys\n", __func__);
return -ENOMEM;
}
/* Set all DMA configuration to be DMA, not SDMA */
writel(0xffffff, S3C64XX_SDMA_SEL);
/* Register standard DMA controllers */
s3c64xx_dma_init1(0, DMACH_UART0, IRQ_DMA0, 0x75000000);
s3c64xx_dma_init1(8, DMACH_PCM1_TX, IRQ_DMA1, 0x75100000);
return 0;
}
arch_initcall(s3c64xx_dma_init);