/*
* driver/dma/coh901318.c
*
* Copyright (C) 2007-2009 ST-Ericsson
* License terms: GNU General Public License (GPL) version 2
* DMA driver for COH 901 318
* Author: Per Friden <per.friden@stericsson.com>
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h> /* printk() */
#include <linux/fs.h> /* everything... */
#include <linux/slab.h> /* kmalloc() */
#include <linux/dmaengine.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/irqreturn.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/debugfs.h>
#include <mach/coh901318.h>
#include "coh901318_lli.h"
#define COHC_2_DEV(cohc) (&cohc->chan.dev->device)
#ifdef VERBOSE_DEBUG
#define COH_DBG(x) ({ if (1) x; 0; })
#else
#define COH_DBG(x) ({ if (0) x; 0; })
#endif
struct coh901318_desc {
struct dma_async_tx_descriptor desc;
struct list_head node;
struct scatterlist *sg;
unsigned int sg_len;
struct coh901318_lli *lli;
enum dma_data_direction dir;
unsigned long flags;
};
struct coh901318_base {
struct device *dev;
void __iomem *virtbase;
struct coh901318_pool pool;
struct powersave pm;
struct dma_device dma_slave;
struct dma_device dma_memcpy;
struct coh901318_chan *chans;
struct coh901318_platform *platform;
};
struct coh901318_chan {
spinlock_t lock;
int allocated;
int completed;
int id;
int stopped;
struct work_struct free_work;
struct dma_chan chan;
struct tasklet_struct tasklet;
struct list_head active;
struct list_head queue;
struct list_head free;
unsigned long nbr_active_done;
unsigned long busy;
u32 runtime_addr;
u32 runtime_ctrl;
struct coh901318_base *base;
};
static void coh901318_list_print(struct coh901318_chan *cohc,
struct coh901318_lli *lli)
{
struct coh901318_lli *l = lli;
int i = 0;
while (l) {
dev_vdbg(COHC_2_DEV(cohc), "i %d, lli %p, ctrl 0x%x, src 0x%x"
", dst 0x%x, link 0x%x virt_link_addr 0x%p\n",
i, l, l->control, l->src_addr, l->dst_addr,
l->link_addr, l->virt_link_addr);
i++;
l = l->virt_link_addr;
}
}
#ifdef CONFIG_DEBUG_FS
#define COH901318_DEBUGFS_ASSIGN(x, y) (x = y)
static struct coh901318_base *debugfs_dma_base;
static struct dentry *dma_dentry;
static int coh901318_debugfs_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static int coh901318_debugfs_read(struct file *file, char __user *buf,
size_t count, loff_t *f_pos)
{
u64 started_channels = debugfs_dma_base->pm.started_channels;
int pool_count = debugfs_dma_base->pool.debugfs_pool_counter;
int i;
int ret = 0;
char *dev_buf;
char *tmp;
int dev_size;
dev_buf = kmalloc(4*1024, GFP_KERNEL);
if (dev_buf == NULL)
goto err_kmalloc;
tmp = dev_buf;
tmp += sprintf(tmp, "DMA -- enabled dma channels\n");
for (i = 0; i < debugfs_dma_base->platform->max_channels; i++)
if (started_channels & (1 << i))
tmp += sprintf(tmp, "channel %d\n", i);
tmp += sprintf(tmp, "Pool alloc nbr %d\n", pool_count);
dev_size = tmp - dev_buf;
/* No more to read if offset != 0 */
if (*f_pos > dev_size)
goto out;
if (count > dev_size - *f_pos)
count = dev_size - *f_pos;
if (copy_to_user(buf, dev_buf + *f_pos, count))
ret = -EINVAL;
ret = count;
*f_pos += count;
out:
kfree(dev_buf);
return ret;
err_kmalloc:
return 0;
}
static const struct file_operations coh901318_debugfs_status_operations = {
.owner = THIS_MODULE,
.open = coh901318_debugfs_open,
.read = coh901318_debugfs_read,
.llseek = default_llseek,
};
static int __init init_coh901318_debugfs(void)
{
dma_dentry = debugfs_create_dir("dma", NULL);
(void) debugfs_create_file("status",
S_IFREG | S_IRUGO,
dma_dentry, NULL,
&coh901318_debugfs_status_operations);
return 0;
}
static void __exit exit_coh901318_debugfs(void)
{
debugfs_remove_recursive(dma_dentry);
}
module_init(init_coh901318_debugfs);
module_exit(exit_coh901318_debugfs);
#else
#define COH901318_DEBUGFS_ASSIGN(x, y)
#endif /* CONFIG_DEBUG_FS */
static inline struct coh901318_chan *to_coh901318_chan(struct dma_chan *chan)
{
return container_of(chan, struct coh901318_chan, chan);
}
static inline dma_addr_t
cohc_dev_addr(struct coh901318_chan *cohc)
{
/* Runtime supplied address will take precedence */
if (cohc->runtime_addr)
return cohc->runtime_addr;
return cohc->base->platform->chan_conf[cohc->id].dev_addr;
}
static inline const struct coh901318_params *
cohc_chan_param(struct coh901318_chan *cohc)
{
return &cohc->base->platform->chan_conf[cohc->id].param;
}
static inline const struct coh_dma_channel *
cohc_chan_conf(struct coh901318_chan *cohc)
{
return &cohc->base->platform->chan_conf[cohc->id];
}
static void enable_powersave(struct coh901318_chan *cohc)
{
unsigned long flags;
struct powersave *pm = &cohc->base->pm;
spin_lock_irqsave(&pm->lock, flags);
pm->started_channels &= ~(1ULL << cohc->id);
if (!pm->started_channels) {
/* DMA no longer intends to access memory */
cohc->base->platform->access_memory_state(cohc->base->dev,
false);
}
spin_unlock_irqrestore(&pm->lock, flags);
}
static void disable_powersave(struct coh901318_chan *cohc)
{
unsigned long flags;
struct powersave *pm = &cohc->base->pm;
spin_lock_irqsave(&pm->lock, flags);
if (!pm->started_channels) {
/* DMA intends to access memory */
cohc->base->platform->access_memory_state(cohc->base->dev,
true);
}
pm->started_channels |= (1ULL << cohc->id);
spin_unlock_irqrestore(&pm->lock, flags);
}
static inline int coh901318_set_ctrl(struct coh901318_chan *cohc, u32 control)
{
int channel = cohc->id;
void __iomem *virtbase = cohc->base->virtbase;
writel(control,
virtbase + COH901318_CX_CTRL +
COH901318_CX_CTRL_SPACING * channel);
return 0;
}
static inline int coh901318_set_conf(struct coh901318_chan *cohc, u32 conf)
{
int channel = cohc->id;
void __iomem *virtbase = cohc->base->virtbase;
writel(conf,
virtbase + COH901318_CX_CFG +
COH901318_CX_CFG_SPACING*channel);
return 0;
}
static int coh901318_start(struct coh901318_chan *cohc)
{
u32 val;
int channel = cohc->id;
void __iomem *virtbase = cohc->base->virtbase;
disable_powersave(cohc);
val = readl(virtbase + COH901318_CX_CFG +
COH901318_CX_CFG_SPACING * channel);
/* Enable channel */
val |= COH901318_CX_CFG_CH_ENABLE;
writel(val, virtbase + COH901318_CX_CFG +
COH901318_CX_CFG_SPACING * channel);
return 0;
}
static int coh901318_prep_linked_list(struct coh901318_chan *cohc,
struct coh901318_lli *lli)
{
int channel = cohc->id;
void __iomem *virtbase = cohc->base->virtbase;
BUG_ON(readl(virtbase + COH901318_CX_STAT +
COH901318_CX_STAT_SPACING*channel) &
COH901318_CX_STAT_ACTIVE);
writel(lli->src_addr,
virtbase + COH901318_CX_SRC_ADDR +
COH901318_CX_SRC_ADDR_SPACING * channel);
writel(lli->dst_addr, virtbase +
COH901318_CX_DST_ADDR +
COH901318_CX_DST_ADDR_SPACING * channel);
writel(lli->link_addr, virtbase + COH901318_CX_LNK_ADDR +
COH901318_CX_LNK_ADDR_SPACING * channel);
writel(lli->control, virtbase + COH901318_CX_CTRL +
COH901318_CX_CTRL_SPACING * channel);
return 0;
}
static dma_cookie_t
coh901318_assign_cookie(struct coh901318_chan *cohc,
struct coh901318_desc *cohd)
{
dma_cookie_t cookie = cohc->chan.cookie;
if (++cookie < 0)
cookie = 1;
cohc->chan.cookie = cookie;
cohd->desc.cookie = cookie;
return cookie;
}
static struct coh901318_desc *
coh901318_desc_get(struct coh901318_chan *cohc)
{
struct coh901318_desc *desc;
if (list_empty(&cohc->free)) {
/* alloc new desc because we're out of used ones
* TODO: alloc a pile of descs instead of just one,
* avoid many small allocations.
*/
desc = kzalloc(sizeof(struct coh901318_desc), GFP_NOWAIT);
if (desc == NULL)
goto out;
INIT_LIST_HEAD(&desc->node);
dma_async_tx_descriptor_init(&desc->desc, &cohc->chan);
} else {
/* Reuse an old desc. */
desc = list_first_entry(&cohc->free,
struct coh901318_desc,
node);
list_del(&desc->node);
/* Initialize it a bit so it's not insane */
desc->sg = NULL;
desc->sg_len = 0;
desc->desc.callback = NULL;
desc->desc.callback_param = NULL;
}
out:
return desc;
}
static void
coh901318_desc_free(struct coh901318_chan *cohc, struct coh901318_desc *cohd)
{
list_add_tail(&cohd->node, &cohc->free);
}
/* call with irq lock held */
static void
coh901318_desc_submit(struct coh901318_chan *cohc, struct coh901318_desc *desc)
{
list_add_tail(&desc->node, &cohc->active);
}
static struct coh901318_desc *
coh901318_first_active_get(struct coh901318_chan *cohc)
{
struct coh901318_desc *d;
if (list_empty(&cohc->active))
return NULL;
d = list_first_entry(&cohc->active,
struct coh901318_desc,
node);
return d;
}
static void
coh901318_desc_remove(struct coh901318_desc *cohd)
{
list_del(&cohd->node);
}
static void
coh901318_desc_queue(struct coh901318_chan *cohc, struct coh901318_desc *desc)
{
list_add_tail(&desc->node, &cohc->queue);
}
static struct coh901318_desc *
coh901318_first_queued(struct coh901318_chan *cohc)
{
struct coh901318_desc *d;
if (list_empty(&cohc->queue))
return NULL;
d = list_first_entry(&cohc->queue,
struct coh901318_desc,
node);
return d;
}
static inline u32 coh901318_get_bytes_in_lli(struct coh901318_lli *in_lli)
{
struct coh901318_lli *lli = in_lli;
u32 bytes = 0;
while (lli) {
bytes += lli->control & COH901318_CX_CTRL_TC_VALUE_MASK;
lli = lli->virt_link_addr;
}
return bytes;
}
/*
* Get the number of bytes left to transfer on this channel,
* it is unwise to call this before stopping the channel for
* absolute measures, but for a rough guess you can still call
* it.
*/
static u32 coh901318_get_bytes_left(struct dma_chan *chan)
{
struct coh901318_chan *cohc = to_coh901318_chan(chan);
struct coh901318_desc *cohd;
struct list_head *pos;
unsigned long flags;
u32 left = 0;
int i = 0;
spin_lock_irqsave(&cohc->lock, flags);
/*
* If there are many queued jobs, we iterate and add the
* size of them all. We take a special look on the first
* job though, since it is probably active.
*/
list_for_each(pos, &cohc->active) {
/*
* The first job in the list will be working on the
* hardware. The job can be stopped but still active,
* so that the transfer counter is somewhere inside
* the buffer.
*/
cohd = list_entry(pos, struct coh901318_desc, node);
if (i == 0) {
struct coh901318_lli *lli;
dma_addr_t ladd;
/* Read current transfer count value */
left = readl(cohc->base->virtbase +
COH901318_CX_CTRL +
COH901318_CX_CTRL_SPACING * cohc->id) &
COH901318_CX_CTRL_TC_VALUE_MASK;
/* See if the transfer is linked... */
ladd = readl(cohc->base->virtbase +
COH901318_CX_LNK_ADDR +
COH901318_CX_LNK_ADDR_SPACING *
cohc->id) &
~COH901318_CX_LNK_LINK_IMMEDIATE;
/* Single transaction */
if (!ladd)
continue;
/*
* Linked transaction, follow the lli, find the
* currently processing lli, and proceed to the next
*/
lli = cohd->lli;
while (lli && lli->link_addr != ladd)
lli = lli->virt_link_addr;
if (lli)
lli = lli->virt_link_addr;
/*
* Follow remaining lli links around to count the total
* number of bytes left
*/
left += coh901318_get_bytes_in_lli(lli);
} else {
left += coh901318_get_bytes_in_lli(cohd->lli);
}
i++;
}
/* Also count bytes in the queued jobs */
list_for_each(pos, &cohc->queue) {
cohd = list_entry(pos, struct coh901318_desc, node);
left += coh901318_get_bytes_in_lli(cohd->lli);
}
spin_unlock_irqrestore(&cohc->lock, flags);
return left;
}
/*
* Pauses a transfer without losing data. Enables power save.
* Use this function in conjunction with coh901318_resume.
*/
static void coh901318_pause(struct dma_chan *chan)
{
u32 val;
unsigned long flags;
struct coh901318_chan *cohc = to_coh901318_chan(chan);
int channel = cohc->id;
void __iomem *virtbase = cohc->base->virtbase;
spin_lock_irqsave(&cohc->lock, flags);
/* Disable channel in HW */
val = readl(virtbase + COH901318_CX_CFG +
COH901318_CX_CFG_SPACING * channel);
/* Stopping infinite transfer */
if ((val & COH901318_CX_CTRL_TC_ENABLE) == 0 &&
(val & COH901318_CX_CFG_CH_ENABLE))
cohc->stopped = 1;
val &= ~COH901318_CX_CFG_CH_ENABLE;
/* Enable twice, HW bug work around */
writel(val, virtbase + COH901318_CX_CFG +
COH901318_CX_CFG_SPACING * channel);
writel(val, virtbase + COH901318_CX_CFG +
COH901318_CX_CFG_SPACING * channel);
/* Spin-wait for it to actually go inactive */
while (readl(virtbase + COH901318_CX_STAT+COH901318_CX_STAT_SPACING *
channel) & COH901318_CX_STAT_ACTIVE)
cpu_relax();
/* Check if we stopped an active job */
if ((readl(virtbase + COH901318_CX_CTRL+COH901318_CX_CTRL_SPACING *
channel) & COH901318_CX_CTRL_TC_VALUE_MASK) > 0)
cohc->stopped = 1;
enable_powersave(cohc);
spin_unlock_irqrestore(&cohc->lock, flags);
}
/* Resumes a transfer that has been stopped via 300_dma_stop(..).
Power save is handled.
*/
static void coh901318_resume(struct dma_chan *chan)
{
u32 val;
unsigned long flags;
struct coh901318_chan *cohc = to_coh901318_chan(chan);
int channel = cohc->id;
spin_lock_irqsave(&cohc->lock, flags);
disable_powersave(cohc);
if (cohc->stopped) {
/* Enable channel in HW */
val = readl(cohc->base->virtbase + COH901318_CX_CFG +
COH901318_CX_CFG_SPACING * channel);
val |= COH901318_CX_CFG_CH_ENABLE;
writel(val, cohc->base->virtbase + COH901318_CX_CFG +
COH901318_CX_CFG_SPACING*channel);
cohc->stopped = 0;
}
spin_unlock_irqrestore(&cohc->lock, flags);
}
bool coh901318_filter_id(struct dma_chan *chan, void *chan_id)
{
unsigned int ch_nr = (unsigned int) chan_id;
if (ch_nr == to_coh901318_chan(chan)->id)
return true;
return false;
}
EXPORT_SYMBOL(coh901318_filter_id);
/*
* DMA channel allocation
*/
static int coh901318_config(struct coh901318_chan *cohc,
struct coh901318_params *param)
{
unsigned long flags;
const struct coh901318_params *p;
int channel = cohc->id;
void __iomem *virtbase = cohc->base->virtbase;
spin_lock_irqsave(&cohc->lock, flags);
if (param)
p = param;
else
p = &cohc->base->platform->chan_conf[channel].param;
/* Clear any pending BE or TC interrupt */
if (channel < 32) {
writel(1 << channel, virtbase + COH901318_BE_INT_CLEAR1);
writel(1 << channel, virtbase + COH901318_TC_INT_CLEAR1);
} else {
writel(1 << (channel - 32), virtbase +
COH901318_BE_INT_CLEAR2);
writel(1 << (channel - 32), virtbase +
COH901318_TC_INT_CLEAR2);
}
coh901318_set_conf(cohc, p->config);
coh901318_set_ctrl(cohc, p->ctrl_lli_last);
spin_unlock_irqrestore(&cohc->lock, flags);
return 0;
}
/* must lock when calling this function
* start queued jobs, if any
* TODO: start all queued jobs in one go
*
* Returns descriptor if queued job is started otherwise NULL.
* If the queue is empty NULL is returned.
*/
static struct coh901318_desc *coh901318_queue_start(struct coh901318_chan *cohc)
{
struct coh901318_desc *cohd;
/*
* start queued jobs, if any
* TODO: transmit all queued jobs in one go
*/
cohd = coh901318_first_queued(cohc);
if (cohd != NULL) {
/* Remove from queue */
coh901318_desc_remove(cohd);
/* initiate DMA job */
cohc->busy = 1;
coh901318_desc_submit(cohc, cohd);
coh901318_prep_linked_list(cohc, cohd->lli);
/* start dma job on this channel */
coh901318_start(cohc);
}
return cohd;
}
/*
* This tasklet is called from the interrupt handler to
* handle each descriptor (DMA job) that is sent to a channel.
*/
static void dma_tasklet(unsigned long data)
{
struct coh901318_chan *cohc = (struct coh901318_chan *) data;
struct coh901318_desc *cohd_fin;
unsigned long flags;
dma_async_tx_callback callback;
void *callback_param;
dev_vdbg(COHC_2_DEV(cohc), "[%s] chan_id %d"
" nbr_active_done %ld\n", __func__,
cohc->id, cohc->nbr_active_done);
spin_lock_irqsave(&cohc->lock, flags);
/* get first active descriptor entry from list */
cohd_fin = coh901318_first_active_get(cohc);
if (cohd_fin == NULL)
goto err;
/* locate callback to client */
callback = cohd_fin->desc.callback;
callback_param = cohd_fin->desc.callback_param;
/* sign this job as completed on the channel */
cohc->completed = cohd_fin->desc.cookie;
/* release the lli allocation and remove the descriptor */
coh901318_lli_free(&cohc->base->pool, &cohd_fin->lli);
/* return desc to free-list */
coh901318_desc_remove(cohd_fin);
coh901318_desc_free(cohc, cohd_fin);
spin_unlock_irqrestore(&cohc->lock, flags);
/* Call the callback when we're done */
if (callback)
callback(callback_param);
spin_lock_irqsave(&cohc->lock, flags);
/*
* If another interrupt fired while the tasklet was scheduling,
* we don't get called twice, so we have this number of active
* counter that keep track of the number of IRQs expected to
* be handled for this channel. If there happen to be more than
* one IRQ to be ack:ed, we simply schedule this tasklet again.
*/
cohc->nbr_active_done--;
if (cohc->nbr_active_done) {
dev_dbg(COHC_2_DEV(cohc), "scheduling tasklet again, new IRQs "
"came in while we were scheduling this tasklet\n");
if (cohc_chan_conf(cohc)->priority_high)
tasklet_hi_schedule(&cohc->tasklet);
else
tasklet_schedule(&cohc->tasklet);
}
spin_unlock_irqrestore(&cohc->lock, flags);
return;
err:
spin_unlock_irqrestore(&cohc->lock, flags);
dev_err(COHC_2_DEV(cohc), "[%s] No active dma desc\n", __func__);
}
/* called from interrupt context */
static void dma_tc_handle(struct coh901318_chan *cohc)
{
/*
* If the channel is not allocated, then we shouldn't have
* any TC interrupts on it.
*/
if (!cohc->allocated) {
dev_err(COHC_2_DEV(cohc), "spurious interrupt from "
"unallocated channel\n");
return;
}
spin_lock(&cohc->lock);
/*
* When we reach this point, at least one queue item
* should have been moved over from cohc->queue to
* cohc->active and run to completion, that is why we're
* getting a terminal count interrupt is it not?
* If you get this BUG() the most probable cause is that
* the individual nodes in the lli chain have IRQ enabled,
* so check your platform config for lli chain ctrl.
*/
BUG_ON(list_empty(&cohc->active));
cohc->nbr_active_done++;
/*
* This attempt to take a job from cohc->queue, put it
* into cohc->active and start it.
*/
if (coh901318_queue_start(cohc) == NULL)
cohc->busy = 0;
spin_unlock(&cohc->lock);
/*
* This tasklet will remove items from cohc->active
* and thus terminates them.
*/
if (cohc_chan_conf(cohc)->priority_high)
tasklet_hi_schedule(&cohc->tasklet);
else
tasklet_schedule(&cohc->tasklet);
}
static irqreturn_t dma_irq_handler(int irq, void *dev_id)
{
u32 status1;
u32 status2;
int i;
int ch;
struct coh901318_base *base = dev_id;
struct coh901318_chan *cohc;
void __iomem *virtbase = base->virtbase;
status1 = readl(virtbase + COH901318_INT_STATUS1);
status2 = readl(virtbase + COH901318_INT_STATUS2);
if (unlikely(status1 == 0 && status2 == 0)) {
dev_warn(base->dev, "spurious DMA IRQ from no channel!\n");
return IRQ_HANDLED;
}
/* TODO: consider handle IRQ in tasklet here to
* minimize interrupt latency */
/* Check the first 32 DMA channels for IRQ */
while (status1) {
/* Find first bit set, return as a number. */
i = ffs(status1) - 1;
ch = i;
cohc = &base->chans[ch];
spin_lock(&cohc->lock);
/* Mask off this bit */
status1 &= ~(1 << i);
/* Check the individual channel bits */
if (test_bit(i, virtbase + COH901318_BE_INT_STATUS1)) {
dev_crit(COHC_2_DEV(cohc),
"DMA bus error on channel %d!\n", ch);
BUG_ON(1);
/* Clear BE interrupt */
__set_bit(i, virtbase + COH901318_BE_INT_CLEAR1);
} else {
/* Caused by TC, really? */
if (unlikely(!test_bit(i, virtbase +
COH901318_TC_INT_STATUS1))) {
dev_warn(COHC_2_DEV(cohc),
"ignoring interrupt not caused by terminal count on channel %d\n", ch);
/* Clear TC interrupt */
BUG_ON(1);
__set_bit(i, virtbase + COH901318_TC_INT_CLEAR1);
} else {
/* Enable powersave if transfer has finished */
if (!(readl(virtbase + COH901318_CX_STAT +
COH901318_CX_STAT_SPACING*ch) &
COH901318_CX_STAT_ENABLED)) {
enable_powersave(cohc);
}
/* Must clear TC interrupt before calling
* dma_tc_handle
* in case tc_handle initiate a new dma job
*/
__set_bit(i, virtbase + COH901318_TC_INT_CLEAR1);
dma_tc_handle(cohc);
}
}
spin_unlock(&cohc->lock);
}
/* Check the remaining 32 DMA channels for IRQ */
while (status2) {
/* Find first bit set, return as a number. */
i = ffs(status2) - 1;
ch = i + 32;
cohc = &base->chans[ch];
spin_lock(&cohc->lock);
/* Mask off this bit */
status2 &= ~(1 << i);
/* Check the individual channel bits */
if (test_bit(i, virtbase + COH901318_BE_INT_STATUS2)) {
dev_crit(COHC_2_DEV(cohc),
"DMA bus error on channel %d!\n", ch);
/* Clear BE interrupt */
BUG_ON(1);
__set_bit(i, virtbase + COH901318_BE_INT_CLEAR2);
} else {
/* Caused by TC, really? */
if (unlikely(!test_bit(i, virtbase +
COH901318_TC_INT_STATUS2))) {
dev_warn(COHC_2_DEV(cohc),
"ignoring interrupt not caused by terminal count on channel %d\n", ch);
/* Clear TC interrupt */
__set_bit(i, virtbase + COH901318_TC_INT_CLEAR2);
BUG_ON(1);
} else {
/* Enable powersave if transfer has finished */
if (!(readl(virtbase + COH901318_CX_STAT +
COH901318_CX_STAT_SPACING*ch) &
COH901318_CX_STAT_ENABLED)) {
enable_powersave(cohc);
}
/* Must clear TC interrupt before calling
* dma_tc_handle
* in case tc_handle initiate a new dma job
*/
__set_bit(i, virtbase + COH901318_TC_INT_CLEAR2);
dma_tc_handle(cohc);
}
}
spin_unlock(&cohc->lock);
}
return IRQ_HANDLED;
}
static int coh901318_alloc_chan_resources(struct dma_chan *chan)
{
struct coh901318_chan *cohc = to_coh901318_chan(chan);
unsigned long flags;
dev_vdbg(COHC_2_DEV(cohc), "[%s] DMA channel %d\n",
__func__, cohc->id);
if (chan->client_count > 1)
return -EBUSY;
spin_lock_irqsave(&cohc->lock, flags);
coh901318_config(cohc, NULL);
cohc->allocated = 1;
cohc->completed = chan->cookie = 1;
spin_unlock_irqrestore(&cohc->lock, flags);
return 1;
}
static void
coh901318_free_chan_resources(struct dma_chan *chan)
{
struct coh901318_chan *cohc = to_coh901318_chan(chan);
int channel = cohc->id;
unsigned long flags;
spin_lock_irqsave(&cohc->lock, flags);
/* Disable HW */
writel(0x00000000U, cohc->base->virtbase + COH901318_CX_CFG +
COH901318_CX_CFG_SPACING*channel);
writel(0x00000000U, cohc->base->virtbase + COH901318_CX_CTRL +
COH901318_CX_CTRL_SPACING*channel);
cohc->allocated = 0;
spin_unlock_irqrestore(&cohc->lock, flags);
chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
}
static dma_cookie_t
coh901318_tx_submit(struct dma_async_tx_descriptor *tx)
{
struct coh901318_desc *cohd = container_of(tx, struct coh901318_desc,
desc);
struct coh901318_chan *cohc = to_coh901318_chan(tx->chan);
unsigned long flags;
spin_lock_irqsave(&cohc->lock, flags);
tx->cookie = coh901318_assign_cookie(cohc, cohd);
coh901318_desc_queue(cohc, cohd);
spin_unlock_irqrestore(&cohc->lock, flags);
return tx->cookie;
}
static struct dma_async_tx_descriptor *
coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
size_t size, unsigned long flags)
{
struct coh901318_lli *lli;
struct coh901318_desc *cohd;
unsigned long flg;
struct coh901318_chan *cohc = to_coh901318_chan(chan);
int lli_len;
u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
int ret;
spin_lock_irqsave(&cohc->lock, flg);
dev_vdbg(COHC_2_DEV(cohc),
"[%s] channel %d src 0x%x dest 0x%x size %d\n",
__func__, cohc->id, src, dest, size);
if (flags & DMA_PREP_INTERRUPT)
/* Trigger interrupt after last lli */
ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
lli_len = size >> MAX_DMA_PACKET_SIZE_SHIFT;
if ((lli_len << MAX_DMA_PACKET_SIZE_SHIFT) < size)
lli_len++;
lli = coh901318_lli_alloc(&cohc->base->pool, lli_len);
if (lli == NULL)
goto err;
ret = coh901318_lli_fill_memcpy(
&cohc->base->pool, lli, src, size, dest,
cohc_chan_param(cohc)->ctrl_lli_chained,
ctrl_last);
if (ret)
goto err;
COH_DBG(coh901318_list_print(cohc, lli));
/* Pick a descriptor to handle this transfer */
cohd = coh901318_desc_get(cohc);
cohd->lli = lli;
cohd->flags = flags;
cohd->desc.tx_submit = coh901318_tx_submit;
spin_unlock_irqrestore(&cohc->lock, flg);
return &cohd->desc;
err:
spin_unlock_irqrestore(&cohc->lock, flg);
return NULL;
}
static struct dma_async_tx_descriptor *
coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_data_direction direction,
unsigned long flags)
{
struct coh901318_chan *cohc = to_coh901318_chan(chan);
struct coh901318_lli *lli;
struct coh901318_desc *cohd;
const struct coh901318_params *params;
struct scatterlist *sg;
int len = 0;
int size;
int i;
u32 ctrl_chained = cohc_chan_param(cohc)->ctrl_lli_chained;
u32 ctrl = cohc_chan_param(cohc)->ctrl_lli;
u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
u32 config;
unsigned long flg;
int ret;
if (!sgl)
goto out;
if (sgl->length == 0)
goto out;
spin_lock_irqsave(&cohc->lock, flg);
dev_vdbg(COHC_2_DEV(cohc), "[%s] sg_len %d dir %d\n",
__func__, sg_len, direction);
if (flags & DMA_PREP_INTERRUPT)
/* Trigger interrupt after last lli */
ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
params = cohc_chan_param(cohc);
config = params->config;
/*
* Add runtime-specific control on top, make
* sure the bits you set per peripheral channel are
* cleared in the default config from the platform.
*/
ctrl_chained |= cohc->runtime_ctrl;
ctrl_last |= cohc->runtime_ctrl;
ctrl |= cohc->runtime_ctrl;
if (direction == DMA_TO_DEVICE) {
u32 tx_flags = COH901318_CX_CTRL_PRDD_SOURCE |
COH901318_CX_CTRL_SRC_ADDR_INC_ENABLE;
config |= COH901318_CX_CFG_RM_MEMORY_TO_PRIMARY;
ctrl_chained |= tx_flags;
ctrl_last |= tx_flags;
ctrl |= tx_flags;
} else if (direction == DMA_FROM_DEVICE) {
u32 rx_flags = COH901318_CX_CTRL_PRDD_DEST |
COH901318_CX_CTRL_DST_ADDR_INC_ENABLE;
config |= COH901318_CX_CFG_RM_PRIMARY_TO_MEMORY;
ctrl_chained |= rx_flags;
ctrl_last |= rx_flags;
ctrl |= rx_flags;
} else
goto err_direction;
coh901318_set_conf(cohc, config);
/* The dma only supports transmitting packages up to
* MAX_DMA_PACKET_SIZE. Calculate to total number of
* dma elemts required to send the entire sg list
*/
for_each_sg(sgl, sg, sg_len, i) {
unsigned int factor;
size = sg_dma_len(sg);
if (size <= MAX_DMA_PACKET_SIZE) {
len++;
continue;
}
factor = size >> MAX_DMA_PACKET_SIZE_SHIFT;
if ((factor << MAX_DMA_PACKET_SIZE_SHIFT) < size)
factor++;
len += factor;
}
pr_debug("Allocate %d lli:s for this transfer\n", len);
lli = coh901318_lli_alloc(&cohc->base->pool, len);
if (lli == NULL)
goto err_dma_alloc;
/* initiate allocated lli list */
ret = coh901318_lli_fill_sg(&cohc->base->pool, lli, sgl, sg_len,
cohc_dev_addr(cohc),
ctrl_chained,
ctrl,
ctrl_last,
direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
if (ret)
goto err_lli_fill;
/*
* Set the default ctrl for the channel to the one from the lli,
* things may have changed due to odd buffer alignment etc.
*/
coh901318_set_ctrl(cohc, lli->control);
COH_DBG(coh901318_list_print(cohc, lli));
/* Pick a descriptor to handle this transfer */
cohd = coh901318_desc_get(cohc);
cohd->dir = direction;
cohd->flags = flags;
cohd->desc.tx_submit = coh901318_tx_submit;
cohd->lli = lli;
spin_unlock_irqrestore(&cohc->lock, flg);
return &cohd->desc;
err_lli_fill:
err_dma_alloc:
err_direction:
spin_unlock_irqrestore(&cohc->lock, flg);
out:
return NULL;
}
static enum dma_status
coh901318_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
struct dma_tx_state *txstate)
{
struct coh901318_chan *cohc = to_coh901318_chan(chan);
dma_cookie_t last_used;
dma_cookie_t last_complete;
int ret;
last_complete = cohc->completed;
last_used = chan->cookie;
ret = dma_async_is_complete(cookie, last_complete, last_used);
dma_set_tx_state(txstate, last_complete, last_used,
coh901318_get_bytes_left(chan));
if (ret == DMA_IN_PROGRESS && cohc->stopped)
ret = DMA_PAUSED;
return ret;
}
static void
coh901318_issue_pending(struct dma_chan *chan)
{
struct coh901318_chan *cohc = to_coh901318_chan(chan);
unsigned long flags;
spin_lock_irqsave(&cohc->lock, flags);
/*
* Busy means that pending jobs are already being processed,
* and then there is no point in starting the queue: the
* terminal count interrupt on the channel will take the next
* job on the queue and execute it anyway.
*/
if (!cohc->busy)
coh901318_queue_start(cohc);
spin_unlock_irqrestore(&cohc->lock, flags);
}
/*
* Here we wrap in the runtime dma control interface
*/
struct burst_table {
int burst_8bit;
int burst_16bit;
int burst_32bit;
u32 reg;
};
static const struct burst_table burst_sizes[] = {
{
.burst_8bit = 64,
.burst_16bit = 32,
.burst_32bit = 16,
.reg = COH901318_CX_CTRL_BURST_COUNT_64_BYTES,
},
{
.burst_8bit = 48,
.burst_16bit = 24,
.burst_32bit = 12,
.reg = COH901318_CX_CTRL_BURST_COUNT_48_BYTES,
},
{
.burst_8bit = 32,
.burst_16bit = 16,
.burst_32bit = 8,
.reg = COH901318_CX_CTRL_BURST_COUNT_32_BYTES,
},
{
.burst_8bit = 16,
.burst_16bit = 8,
.burst_32bit = 4,
.reg = COH901318_CX_CTRL_BURST_COUNT_16_BYTES,
},
{
.burst_8bit = 8,
.burst_16bit = 4,
.burst_32bit = 2,
.reg = COH901318_CX_CTRL_BURST_COUNT_8_BYTES,
},
{
.burst_8bit = 4,
.burst_16bit = 2,
.burst_32bit = 1,
.reg = COH901318_CX_CTRL_BURST_COUNT_4_BYTES,
},
{
.burst_8bit = 2,
.burst_16bit = 1,
.burst_32bit = 0,
.reg = COH901318_CX_CTRL_BURST_COUNT_2_BYTES,
},
{
.burst_8bit = 1,
.burst_16bit = 0,
.burst_32bit = 0,
.reg = COH901318_CX_CTRL_BURST_COUNT_1_BYTE,
},
};
static void coh901318_dma_set_runtimeconfig(struct dma_chan *chan,
struct dma_slave_config *config)
{
struct coh901318_chan *cohc = to_coh901318_chan(chan);
dma_addr_t addr;
enum dma_slave_buswidth addr_width;
u32 maxburst;
u32 runtime_ctrl = 0;
int i = 0;
/* We only support mem to per or per to mem transfers */
if (config->direction == DMA_FROM_DEVICE) {
addr = config->src_addr;
addr_width = config->src_addr_width;
maxburst = config->src_maxburst;
} else if (config->direction == DMA_TO_DEVICE) {
addr = config->dst_addr;
addr_width = config->dst_addr_width;
maxburst = config->dst_maxburst;
} else {
dev_err(COHC_2_DEV(cohc), "illegal channel mode\n");
return;
}
dev_dbg(COHC_2_DEV(cohc), "configure channel for %d byte transfers\n",
addr_width);
switch (addr_width) {
case DMA_SLAVE_BUSWIDTH_1_BYTE:
runtime_ctrl |=
COH901318_CX_CTRL_SRC_BUS_SIZE_8_BITS |
COH901318_CX_CTRL_DST_BUS_SIZE_8_BITS;
while (i < ARRAY_SIZE(burst_sizes)) {
if (burst_sizes[i].burst_8bit <= maxburst)
break;
i++;
}
break;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
runtime_ctrl |=
COH901318_CX_CTRL_SRC_BUS_SIZE_16_BITS |
COH901318_CX_CTRL_DST_BUS_SIZE_16_BITS;
while (i < ARRAY_SIZE(burst_sizes)) {
if (burst_sizes[i].burst_16bit <= maxburst)
break;
i++;
}
break;
case DMA_SLAVE_BUSWIDTH_4_BYTES:
/* Direction doesn't matter here, it's 32/32 bits */
runtime_ctrl |=
COH901318_CX_CTRL_SRC_BUS_SIZE_32_BITS |
COH901318_CX_CTRL_DST_BUS_SIZE_32_BITS;
while (i < ARRAY_SIZE(burst_sizes)) {
if (burst_sizes[i].burst_32bit <= maxburst)
break;
i++;
}
break;
default:
dev_err(COHC_2_DEV(cohc),
"bad runtimeconfig: alien address width\n");
return;
}
runtime_ctrl |= burst_sizes[i].reg;
dev_dbg(COHC_2_DEV(cohc),
"selected burst size %d bytes for address width %d bytes, maxburst %d\n",
burst_sizes[i].burst_8bit, addr_width, maxburst);
cohc->runtime_addr = addr;
cohc->runtime_ctrl = runtime_ctrl;
}
static int
coh901318_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
unsigned long flags;
struct coh901318_chan *cohc = to_coh901318_chan(chan);
struct coh901318_desc *cohd;
void __iomem *virtbase = cohc->base->virtbase;
if (cmd == DMA_SLAVE_CONFIG) {
struct dma_slave_config *config =
(struct dma_slave_config *) arg;
coh901318_dma_set_runtimeconfig(chan, config);
return 0;
}
if (cmd == DMA_PAUSE) {
coh901318_pause(chan);
return 0;
}
if (cmd == DMA_RESUME) {
coh901318_resume(chan);
return 0;
}
if (cmd != DMA_TERMINATE_ALL)
return -ENXIO;
/* The remainder of this function terminates the transfer */
coh901318_pause(chan);
spin_lock_irqsave(&cohc->lock, flags);
/* Clear any pending BE or TC interrupt */
if (cohc->id < 32) {
writel(1 << cohc->id, virtbase + COH901318_BE_INT_CLEAR1);
writel(1 << cohc->id, virtbase + COH901318_TC_INT_CLEAR1);
} else {
writel(1 << (cohc->id - 32), virtbase +
COH901318_BE_INT_CLEAR2);
writel(1 << (cohc->id - 32), virtbase +
COH901318_TC_INT_CLEAR2);
}
enable_powersave(cohc);
while ((cohd = coh901318_first_active_get(cohc))) {
/* release the lli allocation*/
coh901318_lli_free(&cohc->base->pool, &cohd->lli);
/* return desc to free-list */
coh901318_desc_remove(cohd);
coh901318_desc_free(cohc, cohd);
}
while ((cohd = coh901318_first_queued(cohc))) {
/* release the lli allocation*/
coh901318_lli_free(&cohc->base->pool, &cohd->lli);
/* return desc to free-list */
coh901318_desc_remove(cohd);
coh901318_desc_free(cohc, cohd);
}
cohc->nbr_active_done = 0;
cohc->busy = 0;
spin_unlock_irqrestore(&cohc->lock, flags);
return 0;
}
void coh901318_base_init(struct dma_device *dma, const int *pick_chans,
struct coh901318_base *base)
{
int chans_i;
int i = 0;
struct coh901318_chan *cohc;
INIT_LIST_HEAD(&dma->channels);
for (chans_i = 0; pick_chans[chans_i] != -1; chans_i += 2) {
for (i = pick_chans[chans_i]; i <= pick_chans[chans_i+1]; i++) {
cohc = &base->chans[i];
cohc->base = base;
cohc->chan.device = dma;
cohc->id = i;
/* TODO: do we really need this lock if only one
* client is connected to each channel?
*/
spin_lock_init(&cohc->lock);
cohc->nbr_active_done = 0;
cohc->busy = 0;
INIT_LIST_HEAD(&cohc->free);
INIT_LIST_HEAD(&cohc->active);
INIT_LIST_HEAD(&cohc->queue);
tasklet_init(&cohc->tasklet, dma_tasklet,
(unsigned long) cohc);
list_add_tail(&cohc->chan.device_node,
&dma->channels);
}
}
}
static int __init coh901318_probe(struct platform_device *pdev)
{
int err = 0;
struct coh901318_platform *pdata;
struct coh901318_base *base;
int irq;
struct resource *io;
io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!io)
goto err_get_resource;
/* Map DMA controller registers to virtual memory */
if (request_mem_region(io->start,
resource_size(io),
pdev->dev.driver->name) == NULL) {
err = -EBUSY;
goto err_request_mem;
}
pdata = pdev->dev.platform_data;
if (!pdata)
goto err_no_platformdata;
base = kmalloc(ALIGN(sizeof(struct coh901318_base), 4) +
pdata->max_channels *
sizeof(struct coh901318_chan),
GFP_KERNEL);
if (!base)
goto err_alloc_coh_dma_channels;
base->chans = ((void *)base) + ALIGN(sizeof(struct coh901318_base), 4);
base->virtbase = ioremap(io->start, resource_size(io));
if (!base->virtbase) {
err = -ENOMEM;
goto err_no_ioremap;
}
base->dev = &pdev->dev;
base->platform = pdata;
spin_lock_init(&base->pm.lock);
base->pm.started_channels = 0;
COH901318_DEBUGFS_ASSIGN(debugfs_dma_base, base);
platform_set_drvdata(pdev, base);
irq = platform_get_irq(pdev, 0);
if (irq < 0)
goto err_no_irq;
err = request_irq(irq, dma_irq_handler, IRQF_DISABLED,
"coh901318", base);
if (err) {
dev_crit(&pdev->dev,
"Cannot allocate IRQ for DMA controller!\n");
goto err_request_irq;
}
err = coh901318_pool_create(&base->pool, &pdev->dev,
sizeof(struct coh901318_lli),
32);
if (err)
goto err_pool_create;
/* init channels for device transfers */
coh901318_base_init(&base->dma_slave, base->platform->chans_slave,
base);
dma_cap_zero(base->dma_slave.cap_mask);
dma_cap_set(DMA_SLAVE, base->dma_slave.cap_mask);
base->dma_slave.device_alloc_chan_resources = coh901318_alloc_chan_resources;
base->dma_slave.device_free_chan_resources = coh901318_free_chan_resources;
base->dma_slave.device_prep_slave_sg = coh901318_prep_slave_sg;
base->dma_slave.device_tx_status = coh901318_tx_status;
base->dma_slave.device_issue_pending = coh901318_issue_pending;
base->dma_slave.device_control = coh901318_control;
base->dma_slave.dev = &pdev->dev;
err = dma_async_device_register(&base->dma_slave);
if (err)
goto err_register_slave;
/* init channels for memcpy */
coh901318_base_init(&base->dma_memcpy, base->platform->chans_memcpy,
base);
dma_cap_zero(base->dma_memcpy.cap_mask);
dma_cap_set(DMA_MEMCPY, base->dma_memcpy.cap_mask);
base->dma_memcpy.device_alloc_chan_resources = coh901318_alloc_chan_resources;
base->dma_memcpy.device_free_chan_resources = coh901318_free_chan_resources;
base->dma_memcpy.device_prep_dma_memcpy = coh901318_prep_memcpy;
base->dma_memcpy.device_tx_status = coh901318_tx_status;
base->dma_memcpy.device_issue_pending = coh901318_issue_pending;
base->dma_memcpy.device_control = coh901318_control;
base->dma_memcpy.dev = &pdev->dev;
/*
* This controller can only access address at even 32bit boundaries,
* i.e. 2^2
*/
base->dma_memcpy.copy_align = 2;
err = dma_async_device_register(&base->dma_memcpy);
if (err)
goto err_register_memcpy;
dev_info(&pdev->dev, "Initialized COH901318 DMA on virtual base 0x%08x\n",
(u32) base->virtbase);
return err;
err_register_memcpy:
dma_async_device_unregister(&base->dma_slave);
err_register_slave:
coh901318_pool_destroy(&base->pool);
err_pool_create:
free_irq(platform_get_irq(pdev, 0), base);
err_request_irq:
err_no_irq:
iounmap(base->virtbase);
err_no_ioremap:
kfree(base);
err_alloc_coh_dma_channels:
err_no_platformdata:
release_mem_region(pdev->resource->start,
resource_size(pdev->resource));
err_request_mem:
err_get_resource:
return err;
}
static int __exit coh901318_remove(struct platform_device *pdev)
{
struct coh901318_base *base = platform_get_drvdata(pdev);
dma_async_device_unregister(&base->dma_memcpy);
dma_async_device_unregister(&base->dma_slave);
coh901318_pool_destroy(&base->pool);
free_irq(platform_get_irq(pdev, 0), base);
iounmap(base->virtbase);
kfree(base);
release_mem_region(pdev->resource->start,
resource_size(pdev->resource));
return 0;
}
static struct platform_driver coh901318_driver = {
.remove = __exit_p(coh901318_remove),
.driver = {
.name = "coh901318",
},
};
int __init coh901318_init(void)
{
return platform_driver_probe(&coh901318_driver, coh901318_probe);
}
arch_initcall(coh901318_init);
void __exit coh901318_exit(void)
{
platform_driver_unregister(&coh901318_driver);
}
module_exit(coh901318_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Per Friden");