linux/drivers/dma/omap-dma.c

696 lines
16 KiB
C

/*
* OMAP DMAengine support
*
* 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/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/omap-dma.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include "virt-dma.h"
struct omap_dmadev {
struct dma_device ddev;
spinlock_t lock;
struct tasklet_struct task;
struct list_head pending;
};
struct omap_chan {
struct virt_dma_chan vc;
struct list_head node;
struct dma_slave_config cfg;
unsigned dma_sig;
bool cyclic;
bool paused;
int dma_ch;
struct omap_desc *desc;
unsigned sgidx;
};
struct omap_sg {
dma_addr_t addr;
uint32_t en; /* number of elements (24-bit) */
uint32_t fn; /* number of frames (16-bit) */
};
struct omap_desc {
struct virt_dma_desc vd;
enum dma_transfer_direction dir;
dma_addr_t dev_addr;
int16_t fi; /* for OMAP_DMA_SYNC_PACKET */
uint8_t es; /* OMAP_DMA_DATA_TYPE_xxx */
uint8_t sync_mode; /* OMAP_DMA_SYNC_xxx */
uint8_t sync_type; /* OMAP_DMA_xxx_SYNC* */
uint8_t periph_port; /* Peripheral port */
unsigned sglen;
struct omap_sg sg[0];
};
static const unsigned es_bytes[] = {
[OMAP_DMA_DATA_TYPE_S8] = 1,
[OMAP_DMA_DATA_TYPE_S16] = 2,
[OMAP_DMA_DATA_TYPE_S32] = 4,
};
static inline struct omap_dmadev *to_omap_dma_dev(struct dma_device *d)
{
return container_of(d, struct omap_dmadev, ddev);
}
static inline struct omap_chan *to_omap_dma_chan(struct dma_chan *c)
{
return container_of(c, struct omap_chan, vc.chan);
}
static inline struct omap_desc *to_omap_dma_desc(struct dma_async_tx_descriptor *t)
{
return container_of(t, struct omap_desc, vd.tx);
}
static void omap_dma_desc_free(struct virt_dma_desc *vd)
{
kfree(container_of(vd, struct omap_desc, vd));
}
static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d,
unsigned idx)
{
struct omap_sg *sg = d->sg + idx;
if (d->dir == DMA_DEV_TO_MEM)
omap_set_dma_dest_params(c->dma_ch, OMAP_DMA_PORT_EMIFF,
OMAP_DMA_AMODE_POST_INC, sg->addr, 0, 0);
else
omap_set_dma_src_params(c->dma_ch, OMAP_DMA_PORT_EMIFF,
OMAP_DMA_AMODE_POST_INC, sg->addr, 0, 0);
omap_set_dma_transfer_params(c->dma_ch, d->es, sg->en, sg->fn,
d->sync_mode, c->dma_sig, d->sync_type);
omap_start_dma(c->dma_ch);
}
static void omap_dma_start_desc(struct omap_chan *c)
{
struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
struct omap_desc *d;
if (!vd) {
c->desc = NULL;
return;
}
list_del(&vd->node);
c->desc = d = to_omap_dma_desc(&vd->tx);
c->sgidx = 0;
if (d->dir == DMA_DEV_TO_MEM)
omap_set_dma_src_params(c->dma_ch, d->periph_port,
OMAP_DMA_AMODE_CONSTANT, d->dev_addr, 0, d->fi);
else
omap_set_dma_dest_params(c->dma_ch, d->periph_port,
OMAP_DMA_AMODE_CONSTANT, d->dev_addr, 0, d->fi);
omap_dma_start_sg(c, d, 0);
}
static void omap_dma_callback(int ch, u16 status, void *data)
{
struct omap_chan *c = data;
struct omap_desc *d;
unsigned long flags;
spin_lock_irqsave(&c->vc.lock, flags);
d = c->desc;
if (d) {
if (!c->cyclic) {
if (++c->sgidx < d->sglen) {
omap_dma_start_sg(c, d, c->sgidx);
} else {
omap_dma_start_desc(c);
vchan_cookie_complete(&d->vd);
}
} else {
vchan_cyclic_callback(&d->vd);
}
}
spin_unlock_irqrestore(&c->vc.lock, flags);
}
/*
* This callback schedules all pending channels. We could be more
* clever here by postponing allocation of the real DMA channels to
* this point, and freeing them when our virtual channel becomes idle.
*
* We would then need to deal with 'all channels in-use'
*/
static void omap_dma_sched(unsigned long data)
{
struct omap_dmadev *d = (struct omap_dmadev *)data;
LIST_HEAD(head);
spin_lock_irq(&d->lock);
list_splice_tail_init(&d->pending, &head);
spin_unlock_irq(&d->lock);
while (!list_empty(&head)) {
struct omap_chan *c = list_first_entry(&head,
struct omap_chan, node);
spin_lock_irq(&c->vc.lock);
list_del_init(&c->node);
omap_dma_start_desc(c);
spin_unlock_irq(&c->vc.lock);
}
}
static int omap_dma_alloc_chan_resources(struct dma_chan *chan)
{
struct omap_chan *c = to_omap_dma_chan(chan);
dev_info(c->vc.chan.device->dev, "allocating channel for %u\n", c->dma_sig);
return omap_request_dma(c->dma_sig, "DMA engine",
omap_dma_callback, c, &c->dma_ch);
}
static void omap_dma_free_chan_resources(struct dma_chan *chan)
{
struct omap_chan *c = to_omap_dma_chan(chan);
vchan_free_chan_resources(&c->vc);
omap_free_dma(c->dma_ch);
dev_info(c->vc.chan.device->dev, "freeing channel for %u\n", c->dma_sig);
}
static size_t omap_dma_sg_size(struct omap_sg *sg)
{
return sg->en * sg->fn;
}
static size_t omap_dma_desc_size(struct omap_desc *d)
{
unsigned i;
size_t size;
for (size = i = 0; i < d->sglen; i++)
size += omap_dma_sg_size(&d->sg[i]);
return size * es_bytes[d->es];
}
static size_t omap_dma_desc_size_pos(struct omap_desc *d, dma_addr_t addr)
{
unsigned i;
size_t size, es_size = es_bytes[d->es];
for (size = i = 0; i < d->sglen; i++) {
size_t this_size = omap_dma_sg_size(&d->sg[i]) * es_size;
if (size)
size += this_size;
else if (addr >= d->sg[i].addr &&
addr < d->sg[i].addr + this_size)
size += d->sg[i].addr + this_size - addr;
}
return size;
}
static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
dma_cookie_t cookie, struct dma_tx_state *txstate)
{
struct omap_chan *c = to_omap_dma_chan(chan);
struct virt_dma_desc *vd;
enum dma_status ret;
unsigned long flags;
ret = dma_cookie_status(chan, cookie, txstate);
if (ret == DMA_SUCCESS || !txstate)
return ret;
spin_lock_irqsave(&c->vc.lock, flags);
vd = vchan_find_desc(&c->vc, cookie);
if (vd) {
txstate->residue = omap_dma_desc_size(to_omap_dma_desc(&vd->tx));
} else if (c->desc && c->desc->vd.tx.cookie == cookie) {
struct omap_desc *d = c->desc;
dma_addr_t pos;
if (d->dir == DMA_MEM_TO_DEV)
pos = omap_get_dma_src_pos(c->dma_ch);
else if (d->dir == DMA_DEV_TO_MEM)
pos = omap_get_dma_dst_pos(c->dma_ch);
else
pos = 0;
txstate->residue = omap_dma_desc_size_pos(d, pos);
} else {
txstate->residue = 0;
}
spin_unlock_irqrestore(&c->vc.lock, flags);
return ret;
}
static void omap_dma_issue_pending(struct dma_chan *chan)
{
struct omap_chan *c = to_omap_dma_chan(chan);
unsigned long flags;
spin_lock_irqsave(&c->vc.lock, flags);
if (vchan_issue_pending(&c->vc) && !c->desc) {
struct omap_dmadev *d = to_omap_dma_dev(chan->device);
spin_lock(&d->lock);
if (list_empty(&c->node))
list_add_tail(&c->node, &d->pending);
spin_unlock(&d->lock);
tasklet_schedule(&d->task);
}
spin_unlock_irqrestore(&c->vc.lock, flags);
}
static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl, unsigned sglen,
enum dma_transfer_direction dir, unsigned long tx_flags, void *context)
{
struct omap_chan *c = to_omap_dma_chan(chan);
enum dma_slave_buswidth dev_width;
struct scatterlist *sgent;
struct omap_desc *d;
dma_addr_t dev_addr;
unsigned i, j = 0, es, en, frame_bytes, sync_type;
u32 burst;
if (dir == DMA_DEV_TO_MEM) {
dev_addr = c->cfg.src_addr;
dev_width = c->cfg.src_addr_width;
burst = c->cfg.src_maxburst;
sync_type = OMAP_DMA_SRC_SYNC;
} else if (dir == DMA_MEM_TO_DEV) {
dev_addr = c->cfg.dst_addr;
dev_width = c->cfg.dst_addr_width;
burst = c->cfg.dst_maxburst;
sync_type = OMAP_DMA_DST_SYNC;
} else {
dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
return NULL;
}
/* Bus width translates to the element size (ES) */
switch (dev_width) {
case DMA_SLAVE_BUSWIDTH_1_BYTE:
es = OMAP_DMA_DATA_TYPE_S8;
break;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
es = OMAP_DMA_DATA_TYPE_S16;
break;
case DMA_SLAVE_BUSWIDTH_4_BYTES:
es = OMAP_DMA_DATA_TYPE_S32;
break;
default: /* not reached */
return NULL;
}
/* Now allocate and setup the descriptor. */
d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC);
if (!d)
return NULL;
d->dir = dir;
d->dev_addr = dev_addr;
d->es = es;
d->sync_mode = OMAP_DMA_SYNC_FRAME;
d->sync_type = sync_type;
d->periph_port = OMAP_DMA_PORT_TIPB;
/*
* Build our scatterlist entries: each contains the address,
* the number of elements (EN) in each frame, and the number of
* frames (FN). Number of bytes for this entry = ES * EN * FN.
*
* Burst size translates to number of elements with frame sync.
* Note: DMA engine defines burst to be the number of dev-width
* transfers.
*/
en = burst;
frame_bytes = es_bytes[es] * en;
for_each_sg(sgl, sgent, sglen, i) {
d->sg[j].addr = sg_dma_address(sgent);
d->sg[j].en = en;
d->sg[j].fn = sg_dma_len(sgent) / frame_bytes;
j++;
}
d->sglen = j;
return vchan_tx_prep(&c->vc, &d->vd, tx_flags);
}
static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction dir, unsigned long flags,
void *context)
{
struct omap_chan *c = to_omap_dma_chan(chan);
enum dma_slave_buswidth dev_width;
struct omap_desc *d;
dma_addr_t dev_addr;
unsigned es, sync_type;
u32 burst;
if (dir == DMA_DEV_TO_MEM) {
dev_addr = c->cfg.src_addr;
dev_width = c->cfg.src_addr_width;
burst = c->cfg.src_maxburst;
sync_type = OMAP_DMA_SRC_SYNC;
} else if (dir == DMA_MEM_TO_DEV) {
dev_addr = c->cfg.dst_addr;
dev_width = c->cfg.dst_addr_width;
burst = c->cfg.dst_maxburst;
sync_type = OMAP_DMA_DST_SYNC;
} else {
dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
return NULL;
}
/* Bus width translates to the element size (ES) */
switch (dev_width) {
case DMA_SLAVE_BUSWIDTH_1_BYTE:
es = OMAP_DMA_DATA_TYPE_S8;
break;
case DMA_SLAVE_BUSWIDTH_2_BYTES:
es = OMAP_DMA_DATA_TYPE_S16;
break;
case DMA_SLAVE_BUSWIDTH_4_BYTES:
es = OMAP_DMA_DATA_TYPE_S32;
break;
default: /* not reached */
return NULL;
}
/* Now allocate and setup the descriptor. */
d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC);
if (!d)
return NULL;
d->dir = dir;
d->dev_addr = dev_addr;
d->fi = burst;
d->es = es;
if (burst)
d->sync_mode = OMAP_DMA_SYNC_PACKET;
else
d->sync_mode = OMAP_DMA_SYNC_ELEMENT;
d->sync_type = sync_type;
d->periph_port = OMAP_DMA_PORT_MPUI;
d->sg[0].addr = buf_addr;
d->sg[0].en = period_len / es_bytes[es];
d->sg[0].fn = buf_len / period_len;
d->sglen = 1;
if (!c->cyclic) {
c->cyclic = true;
omap_dma_link_lch(c->dma_ch, c->dma_ch);
if (flags & DMA_PREP_INTERRUPT)
omap_enable_dma_irq(c->dma_ch, OMAP_DMA_FRAME_IRQ);
omap_disable_dma_irq(c->dma_ch, OMAP_DMA_BLOCK_IRQ);
}
if (dma_omap2plus()) {
omap_set_dma_src_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16);
omap_set_dma_dest_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16);
}
return vchan_tx_prep(&c->vc, &d->vd, flags);
}
static int omap_dma_slave_config(struct omap_chan *c, struct dma_slave_config *cfg)
{
if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
return -EINVAL;
memcpy(&c->cfg, cfg, sizeof(c->cfg));
return 0;
}
static int omap_dma_terminate_all(struct omap_chan *c)
{
struct omap_dmadev *d = to_omap_dma_dev(c->vc.chan.device);
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&c->vc.lock, flags);
/* Prevent this channel being scheduled */
spin_lock(&d->lock);
list_del_init(&c->node);
spin_unlock(&d->lock);
/*
* Stop DMA activity: we assume the callback will not be called
* after omap_stop_dma() returns (even if it does, it will see
* c->desc is NULL and exit.)
*/
if (c->desc) {
c->desc = NULL;
/* Avoid stopping the dma twice */
if (!c->paused)
omap_stop_dma(c->dma_ch);
}
if (c->cyclic) {
c->cyclic = false;
c->paused = false;
omap_dma_unlink_lch(c->dma_ch, c->dma_ch);
}
vchan_get_all_descriptors(&c->vc, &head);
spin_unlock_irqrestore(&c->vc.lock, flags);
vchan_dma_desc_free_list(&c->vc, &head);
return 0;
}
static int omap_dma_pause(struct omap_chan *c)
{
/* Pause/Resume only allowed with cyclic mode */
if (!c->cyclic)
return -EINVAL;
if (!c->paused) {
omap_stop_dma(c->dma_ch);
c->paused = true;
}
return 0;
}
static int omap_dma_resume(struct omap_chan *c)
{
/* Pause/Resume only allowed with cyclic mode */
if (!c->cyclic)
return -EINVAL;
if (c->paused) {
omap_start_dma(c->dma_ch);
c->paused = false;
}
return 0;
}
static int omap_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
struct omap_chan *c = to_omap_dma_chan(chan);
int ret;
switch (cmd) {
case DMA_SLAVE_CONFIG:
ret = omap_dma_slave_config(c, (struct dma_slave_config *)arg);
break;
case DMA_TERMINATE_ALL:
ret = omap_dma_terminate_all(c);
break;
case DMA_PAUSE:
ret = omap_dma_pause(c);
break;
case DMA_RESUME:
ret = omap_dma_resume(c);
break;
default:
ret = -ENXIO;
break;
}
return ret;
}
static int omap_dma_chan_init(struct omap_dmadev *od, int dma_sig)
{
struct omap_chan *c;
c = kzalloc(sizeof(*c), GFP_KERNEL);
if (!c)
return -ENOMEM;
c->dma_sig = dma_sig;
c->vc.desc_free = omap_dma_desc_free;
vchan_init(&c->vc, &od->ddev);
INIT_LIST_HEAD(&c->node);
od->ddev.chancnt++;
return 0;
}
static void omap_dma_free(struct omap_dmadev *od)
{
tasklet_kill(&od->task);
while (!list_empty(&od->ddev.channels)) {
struct omap_chan *c = list_first_entry(&od->ddev.channels,
struct omap_chan, vc.chan.device_node);
list_del(&c->vc.chan.device_node);
tasklet_kill(&c->vc.task);
kfree(c);
}
kfree(od);
}
static int omap_dma_probe(struct platform_device *pdev)
{
struct omap_dmadev *od;
int rc, i;
od = kzalloc(sizeof(*od), GFP_KERNEL);
if (!od)
return -ENOMEM;
dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources;
od->ddev.device_free_chan_resources = omap_dma_free_chan_resources;
od->ddev.device_tx_status = omap_dma_tx_status;
od->ddev.device_issue_pending = omap_dma_issue_pending;
od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg;
od->ddev.device_prep_dma_cyclic = omap_dma_prep_dma_cyclic;
od->ddev.device_control = omap_dma_control;
od->ddev.dev = &pdev->dev;
INIT_LIST_HEAD(&od->ddev.channels);
INIT_LIST_HEAD(&od->pending);
spin_lock_init(&od->lock);
tasklet_init(&od->task, omap_dma_sched, (unsigned long)od);
for (i = 0; i < 127; i++) {
rc = omap_dma_chan_init(od, i);
if (rc) {
omap_dma_free(od);
return rc;
}
}
rc = dma_async_device_register(&od->ddev);
if (rc) {
pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n",
rc);
omap_dma_free(od);
} else {
platform_set_drvdata(pdev, od);
}
dev_info(&pdev->dev, "OMAP DMA engine driver\n");
return rc;
}
static int omap_dma_remove(struct platform_device *pdev)
{
struct omap_dmadev *od = platform_get_drvdata(pdev);
dma_async_device_unregister(&od->ddev);
omap_dma_free(od);
return 0;
}
static struct platform_driver omap_dma_driver = {
.probe = omap_dma_probe,
.remove = omap_dma_remove,
.driver = {
.name = "omap-dma-engine",
.owner = THIS_MODULE,
},
};
bool omap_dma_filter_fn(struct dma_chan *chan, void *param)
{
if (chan->device->dev->driver == &omap_dma_driver.driver) {
struct omap_chan *c = to_omap_dma_chan(chan);
unsigned req = *(unsigned *)param;
return req == c->dma_sig;
}
return false;
}
EXPORT_SYMBOL_GPL(omap_dma_filter_fn);
static struct platform_device *pdev;
static const struct platform_device_info omap_dma_dev_info = {
.name = "omap-dma-engine",
.id = -1,
.dma_mask = DMA_BIT_MASK(32),
};
static int omap_dma_init(void)
{
int rc = platform_driver_register(&omap_dma_driver);
if (rc == 0) {
pdev = platform_device_register_full(&omap_dma_dev_info);
if (IS_ERR(pdev)) {
platform_driver_unregister(&omap_dma_driver);
rc = PTR_ERR(pdev);
}
}
return rc;
}
subsys_initcall(omap_dma_init);
static void __exit omap_dma_exit(void)
{
platform_device_unregister(pdev);
platform_driver_unregister(&omap_dma_driver);
}
module_exit(omap_dma_exit);
MODULE_AUTHOR("Russell King");
MODULE_LICENSE("GPL");