linux/drivers/dma/zx296702_dma.c

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/*
* Copyright 2015 Linaro.
*
* 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/sched.h>
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/of_device.h>
#include <linux/of.h>
#include <linux/clk.h>
#include <linux/of_dma.h>
#include "virt-dma.h"
#define DRIVER_NAME "zx-dma"
#define DMA_ALIGN 4
#define DMA_MAX_SIZE (0x10000 - PAGE_SIZE)
#define LLI_BLOCK_SIZE (4 * PAGE_SIZE)
#define REG_ZX_SRC_ADDR 0x00
#define REG_ZX_DST_ADDR 0x04
#define REG_ZX_TX_X_COUNT 0x08
#define REG_ZX_TX_ZY_COUNT 0x0c
#define REG_ZX_SRC_ZY_STEP 0x10
#define REG_ZX_DST_ZY_STEP 0x14
#define REG_ZX_LLI_ADDR 0x1c
#define REG_ZX_CTRL 0x20
#define REG_ZX_TC_IRQ 0x800
#define REG_ZX_SRC_ERR_IRQ 0x804
#define REG_ZX_DST_ERR_IRQ 0x808
#define REG_ZX_CFG_ERR_IRQ 0x80c
#define REG_ZX_TC_IRQ_RAW 0x810
#define REG_ZX_SRC_ERR_IRQ_RAW 0x814
#define REG_ZX_DST_ERR_IRQ_RAW 0x818
#define REG_ZX_CFG_ERR_IRQ_RAW 0x81c
#define REG_ZX_STATUS 0x820
#define REG_ZX_DMA_GRP_PRIO 0x824
#define REG_ZX_DMA_ARB 0x828
#define ZX_FORCE_CLOSE BIT(31)
#define ZX_DST_BURST_WIDTH(x) (((x) & 0x7) << 13)
#define ZX_MAX_BURST_LEN 16
#define ZX_SRC_BURST_LEN(x) (((x) & 0xf) << 9)
#define ZX_SRC_BURST_WIDTH(x) (((x) & 0x7) << 6)
#define ZX_IRQ_ENABLE_ALL (3 << 4)
#define ZX_DST_FIFO_MODE BIT(3)
#define ZX_SRC_FIFO_MODE BIT(2)
#define ZX_SOFT_REQ BIT(1)
#define ZX_CH_ENABLE BIT(0)
#define ZX_DMA_BUSWIDTHS \
(BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
enum zx_dma_burst_width {
ZX_DMA_WIDTH_8BIT = 0,
ZX_DMA_WIDTH_16BIT = 1,
ZX_DMA_WIDTH_32BIT = 2,
ZX_DMA_WIDTH_64BIT = 3,
};
struct zx_desc_hw {
u32 saddr;
u32 daddr;
u32 src_x;
u32 src_zy;
u32 src_zy_step;
u32 dst_zy_step;
u32 reserved1;
u32 lli;
u32 ctr;
u32 reserved[7]; /* pack as hardware registers region size */
} __aligned(32);
struct zx_dma_desc_sw {
struct virt_dma_desc vd;
dma_addr_t desc_hw_lli;
size_t desc_num;
size_t size;
struct zx_desc_hw *desc_hw;
};
struct zx_dma_phy;
struct zx_dma_chan {
struct dma_slave_config slave_cfg;
int id; /* Request phy chan id */
u32 ccfg;
u32 cyclic;
struct virt_dma_chan vc;
struct zx_dma_phy *phy;
struct list_head node;
dma_addr_t dev_addr;
enum dma_status status;
};
struct zx_dma_phy {
u32 idx;
void __iomem *base;
struct zx_dma_chan *vchan;
struct zx_dma_desc_sw *ds_run;
struct zx_dma_desc_sw *ds_done;
};
struct zx_dma_dev {
struct dma_device slave;
void __iomem *base;
spinlock_t lock; /* lock for ch and phy */
struct list_head chan_pending;
struct zx_dma_phy *phy;
struct zx_dma_chan *chans;
struct clk *clk;
struct dma_pool *pool;
u32 dma_channels;
u32 dma_requests;
int irq;
};
#define to_zx_dma(dmadev) container_of(dmadev, struct zx_dma_dev, slave)
static struct zx_dma_chan *to_zx_chan(struct dma_chan *chan)
{
return container_of(chan, struct zx_dma_chan, vc.chan);
}
static void zx_dma_terminate_chan(struct zx_dma_phy *phy, struct zx_dma_dev *d)
{
u32 val = 0;
val = readl_relaxed(phy->base + REG_ZX_CTRL);
val &= ~ZX_CH_ENABLE;
val |= ZX_FORCE_CLOSE;
writel_relaxed(val, phy->base + REG_ZX_CTRL);
val = 0x1 << phy->idx;
writel_relaxed(val, d->base + REG_ZX_TC_IRQ_RAW);
writel_relaxed(val, d->base + REG_ZX_SRC_ERR_IRQ_RAW);
writel_relaxed(val, d->base + REG_ZX_DST_ERR_IRQ_RAW);
writel_relaxed(val, d->base + REG_ZX_CFG_ERR_IRQ_RAW);
}
static void zx_dma_set_desc(struct zx_dma_phy *phy, struct zx_desc_hw *hw)
{
writel_relaxed(hw->saddr, phy->base + REG_ZX_SRC_ADDR);
writel_relaxed(hw->daddr, phy->base + REG_ZX_DST_ADDR);
writel_relaxed(hw->src_x, phy->base + REG_ZX_TX_X_COUNT);
writel_relaxed(0, phy->base + REG_ZX_TX_ZY_COUNT);
writel_relaxed(0, phy->base + REG_ZX_SRC_ZY_STEP);
writel_relaxed(0, phy->base + REG_ZX_DST_ZY_STEP);
writel_relaxed(hw->lli, phy->base + REG_ZX_LLI_ADDR);
writel_relaxed(hw->ctr, phy->base + REG_ZX_CTRL);
}
static u32 zx_dma_get_curr_lli(struct zx_dma_phy *phy)
{
return readl_relaxed(phy->base + REG_ZX_LLI_ADDR);
}
static u32 zx_dma_get_chan_stat(struct zx_dma_dev *d)
{
return readl_relaxed(d->base + REG_ZX_STATUS);
}
static void zx_dma_init_state(struct zx_dma_dev *d)
{
/* set same priority */
writel_relaxed(0x0, d->base + REG_ZX_DMA_ARB);
/* clear all irq */
writel_relaxed(0xffffffff, d->base + REG_ZX_TC_IRQ_RAW);
writel_relaxed(0xffffffff, d->base + REG_ZX_SRC_ERR_IRQ_RAW);
writel_relaxed(0xffffffff, d->base + REG_ZX_DST_ERR_IRQ_RAW);
writel_relaxed(0xffffffff, d->base + REG_ZX_CFG_ERR_IRQ_RAW);
}
static int zx_dma_start_txd(struct zx_dma_chan *c)
{
struct zx_dma_dev *d = to_zx_dma(c->vc.chan.device);
struct virt_dma_desc *vd = vchan_next_desc(&c->vc);
if (!c->phy)
return -EAGAIN;
if (BIT(c->phy->idx) & zx_dma_get_chan_stat(d))
return -EAGAIN;
if (vd) {
struct zx_dma_desc_sw *ds =
container_of(vd, struct zx_dma_desc_sw, vd);
/*
* fetch and remove request from vc->desc_issued
* so vc->desc_issued only contains desc pending
*/
list_del(&ds->vd.node);
c->phy->ds_run = ds;
c->phy->ds_done = NULL;
/* start dma */
zx_dma_set_desc(c->phy, ds->desc_hw);
return 0;
}
c->phy->ds_done = NULL;
c->phy->ds_run = NULL;
return -EAGAIN;
}
static void zx_dma_task(struct zx_dma_dev *d)
{
struct zx_dma_phy *p;
struct zx_dma_chan *c, *cn;
unsigned pch, pch_alloc = 0;
unsigned long flags;
/* check new dma request of running channel in vc->desc_issued */
list_for_each_entry_safe(c, cn, &d->slave.channels,
vc.chan.device_node) {
spin_lock_irqsave(&c->vc.lock, flags);
p = c->phy;
if (p && p->ds_done && zx_dma_start_txd(c)) {
/* No current txd associated with this channel */
dev_dbg(d->slave.dev, "pchan %u: free\n", p->idx);
/* Mark this channel free */
c->phy = NULL;
p->vchan = NULL;
}
spin_unlock_irqrestore(&c->vc.lock, flags);
}
/* check new channel request in d->chan_pending */
spin_lock_irqsave(&d->lock, flags);
while (!list_empty(&d->chan_pending)) {
c = list_first_entry(&d->chan_pending,
struct zx_dma_chan, node);
p = &d->phy[c->id];
if (!p->vchan) {
/* remove from d->chan_pending */
list_del_init(&c->node);
pch_alloc |= 1 << c->id;
/* Mark this channel allocated */
p->vchan = c;
c->phy = p;
} else {
dev_dbg(d->slave.dev, "pchan %u: busy!\n", c->id);
}
}
spin_unlock_irqrestore(&d->lock, flags);
for (pch = 0; pch < d->dma_channels; pch++) {
if (pch_alloc & (1 << pch)) {
p = &d->phy[pch];
c = p->vchan;
if (c) {
spin_lock_irqsave(&c->vc.lock, flags);
zx_dma_start_txd(c);
spin_unlock_irqrestore(&c->vc.lock, flags);
}
}
}
}
static irqreturn_t zx_dma_int_handler(int irq, void *dev_id)
{
struct zx_dma_dev *d = (struct zx_dma_dev *)dev_id;
struct zx_dma_phy *p;
struct zx_dma_chan *c;
u32 tc = readl_relaxed(d->base + REG_ZX_TC_IRQ);
u32 serr = readl_relaxed(d->base + REG_ZX_SRC_ERR_IRQ);
u32 derr = readl_relaxed(d->base + REG_ZX_DST_ERR_IRQ);
u32 cfg = readl_relaxed(d->base + REG_ZX_CFG_ERR_IRQ);
u32 i, irq_chan = 0, task = 0;
while (tc) {
i = __ffs(tc);
tc &= ~BIT(i);
p = &d->phy[i];
c = p->vchan;
if (c) {
unsigned long flags;
spin_lock_irqsave(&c->vc.lock, flags);
if (c->cyclic) {
vchan_cyclic_callback(&p->ds_run->vd);
} else {
vchan_cookie_complete(&p->ds_run->vd);
p->ds_done = p->ds_run;
task = 1;
}
spin_unlock_irqrestore(&c->vc.lock, flags);
irq_chan |= BIT(i);
}
}
if (serr || derr || cfg)
dev_warn(d->slave.dev, "DMA ERR src 0x%x, dst 0x%x, cfg 0x%x\n",
serr, derr, cfg);
writel_relaxed(irq_chan, d->base + REG_ZX_TC_IRQ_RAW);
writel_relaxed(serr, d->base + REG_ZX_SRC_ERR_IRQ_RAW);
writel_relaxed(derr, d->base + REG_ZX_DST_ERR_IRQ_RAW);
writel_relaxed(cfg, d->base + REG_ZX_CFG_ERR_IRQ_RAW);
if (task)
zx_dma_task(d);
return IRQ_HANDLED;
}
static void zx_dma_free_chan_resources(struct dma_chan *chan)
{
struct zx_dma_chan *c = to_zx_chan(chan);
struct zx_dma_dev *d = to_zx_dma(chan->device);
unsigned long flags;
spin_lock_irqsave(&d->lock, flags);
list_del_init(&c->node);
spin_unlock_irqrestore(&d->lock, flags);
vchan_free_chan_resources(&c->vc);
c->ccfg = 0;
}
static enum dma_status zx_dma_tx_status(struct dma_chan *chan,
dma_cookie_t cookie,
struct dma_tx_state *state)
{
struct zx_dma_chan *c = to_zx_chan(chan);
struct zx_dma_phy *p;
struct virt_dma_desc *vd;
unsigned long flags;
enum dma_status ret;
size_t bytes = 0;
ret = dma_cookie_status(&c->vc.chan, cookie, state);
if (ret == DMA_COMPLETE || !state)
return ret;
spin_lock_irqsave(&c->vc.lock, flags);
p = c->phy;
ret = c->status;
/*
* If the cookie is on our issue queue, then the residue is
* its total size.
*/
vd = vchan_find_desc(&c->vc, cookie);
if (vd) {
bytes = container_of(vd, struct zx_dma_desc_sw, vd)->size;
} else if ((!p) || (!p->ds_run)) {
bytes = 0;
} else {
struct zx_dma_desc_sw *ds = p->ds_run;
u32 clli = 0, index = 0;
bytes = 0;
clli = zx_dma_get_curr_lli(p);
index = (clli - ds->desc_hw_lli) / sizeof(struct zx_desc_hw);
for (; index < ds->desc_num; index++) {
bytes += ds->desc_hw[index].src_x;
/* end of lli */
if (!ds->desc_hw[index].lli)
break;
}
}
spin_unlock_irqrestore(&c->vc.lock, flags);
dma_set_residue(state, bytes);
return ret;
}
static void zx_dma_issue_pending(struct dma_chan *chan)
{
struct zx_dma_chan *c = to_zx_chan(chan);
struct zx_dma_dev *d = to_zx_dma(chan->device);
unsigned long flags;
int issue = 0;
spin_lock_irqsave(&c->vc.lock, flags);
/* add request to vc->desc_issued */
if (vchan_issue_pending(&c->vc)) {
spin_lock(&d->lock);
if (!c->phy && list_empty(&c->node)) {
/* if new channel, add chan_pending */
list_add_tail(&c->node, &d->chan_pending);
issue = 1;
dev_dbg(d->slave.dev, "vchan %p: issued\n", &c->vc);
}
spin_unlock(&d->lock);
} else {
dev_dbg(d->slave.dev, "vchan %p: nothing to issue\n", &c->vc);
}
spin_unlock_irqrestore(&c->vc.lock, flags);
if (issue)
zx_dma_task(d);
}
static void zx_dma_fill_desc(struct zx_dma_desc_sw *ds, dma_addr_t dst,
dma_addr_t src, size_t len, u32 num, u32 ccfg)
{
if ((num + 1) < ds->desc_num)
ds->desc_hw[num].lli = ds->desc_hw_lli + (num + 1) *
sizeof(struct zx_desc_hw);
ds->desc_hw[num].saddr = src;
ds->desc_hw[num].daddr = dst;
ds->desc_hw[num].src_x = len;
ds->desc_hw[num].ctr = ccfg;
}
static struct zx_dma_desc_sw *zx_alloc_desc_resource(int num,
struct dma_chan *chan)
{
struct zx_dma_chan *c = to_zx_chan(chan);
struct zx_dma_desc_sw *ds;
struct zx_dma_dev *d = to_zx_dma(chan->device);
int lli_limit = LLI_BLOCK_SIZE / sizeof(struct zx_desc_hw);
if (num > lli_limit) {
dev_dbg(chan->device->dev, "vch %p: sg num %d exceed max %d\n",
&c->vc, num, lli_limit);
return NULL;
}
ds = kzalloc(sizeof(*ds), GFP_ATOMIC);
if (!ds)
return NULL;
ds->desc_hw = dma_pool_alloc(d->pool, GFP_NOWAIT, &ds->desc_hw_lli);
if (!ds->desc_hw) {
dev_dbg(chan->device->dev, "vch %p: dma alloc fail\n", &c->vc);
kfree(ds);
return NULL;
}
memset(ds->desc_hw, 0, sizeof(struct zx_desc_hw) * num);
ds->desc_num = num;
return ds;
}
static enum zx_dma_burst_width zx_dma_burst_width(enum dma_slave_buswidth width)
{
switch (width) {
case DMA_SLAVE_BUSWIDTH_1_BYTE:
case DMA_SLAVE_BUSWIDTH_2_BYTES:
case DMA_SLAVE_BUSWIDTH_4_BYTES:
case DMA_SLAVE_BUSWIDTH_8_BYTES:
return ffs(width) - 1;
default:
return ZX_DMA_WIDTH_32BIT;
}
}
static int zx_pre_config(struct zx_dma_chan *c, enum dma_transfer_direction dir)
{
struct dma_slave_config *cfg = &c->slave_cfg;
enum zx_dma_burst_width src_width;
enum zx_dma_burst_width dst_width;
u32 maxburst = 0;
switch (dir) {
case DMA_MEM_TO_MEM:
c->ccfg = ZX_CH_ENABLE | ZX_SOFT_REQ
| ZX_SRC_BURST_LEN(ZX_MAX_BURST_LEN - 1)
| ZX_SRC_BURST_WIDTH(ZX_DMA_WIDTH_32BIT)
| ZX_DST_BURST_WIDTH(ZX_DMA_WIDTH_32BIT);
break;
case DMA_MEM_TO_DEV:
c->dev_addr = cfg->dst_addr;
/* dst len is calculated from src width, len and dst width.
* We need make sure dst len not exceed MAX LEN.
* Trailing single transaction that does not fill a full
* burst also require identical src/dst data width.
*/
dst_width = zx_dma_burst_width(cfg->dst_addr_width);
maxburst = cfg->dst_maxburst;
maxburst = maxburst < ZX_MAX_BURST_LEN ?
maxburst : ZX_MAX_BURST_LEN;
c->ccfg = ZX_DST_FIFO_MODE | ZX_CH_ENABLE
| ZX_SRC_BURST_LEN(maxburst - 1)
| ZX_SRC_BURST_WIDTH(dst_width)
| ZX_DST_BURST_WIDTH(dst_width);
break;
case DMA_DEV_TO_MEM:
c->dev_addr = cfg->src_addr;
src_width = zx_dma_burst_width(cfg->src_addr_width);
maxburst = cfg->src_maxburst;
maxburst = maxburst < ZX_MAX_BURST_LEN ?
maxburst : ZX_MAX_BURST_LEN;
c->ccfg = ZX_SRC_FIFO_MODE | ZX_CH_ENABLE
| ZX_SRC_BURST_LEN(maxburst - 1)
| ZX_SRC_BURST_WIDTH(src_width)
| ZX_DST_BURST_WIDTH(src_width);
break;
default:
return -EINVAL;
}
return 0;
}
static struct dma_async_tx_descriptor *zx_dma_prep_memcpy(
struct dma_chan *chan, dma_addr_t dst, dma_addr_t src,
size_t len, unsigned long flags)
{
struct zx_dma_chan *c = to_zx_chan(chan);
struct zx_dma_desc_sw *ds;
size_t copy = 0;
int num = 0;
if (!len)
return NULL;
if (zx_pre_config(c, DMA_MEM_TO_MEM))
return NULL;
num = DIV_ROUND_UP(len, DMA_MAX_SIZE);
ds = zx_alloc_desc_resource(num, chan);
if (!ds)
return NULL;
ds->size = len;
num = 0;
do {
copy = min_t(size_t, len, DMA_MAX_SIZE);
zx_dma_fill_desc(ds, dst, src, copy, num++, c->ccfg);
src += copy;
dst += copy;
len -= copy;
} while (len);
c->cyclic = 0;
ds->desc_hw[num - 1].lli = 0; /* end of link */
ds->desc_hw[num - 1].ctr |= ZX_IRQ_ENABLE_ALL;
return vchan_tx_prep(&c->vc, &ds->vd, flags);
}
static struct dma_async_tx_descriptor *zx_dma_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl, unsigned int sglen,
enum dma_transfer_direction dir, unsigned long flags, void *context)
{
struct zx_dma_chan *c = to_zx_chan(chan);
struct zx_dma_desc_sw *ds;
size_t len, avail, total = 0;
struct scatterlist *sg;
dma_addr_t addr, src = 0, dst = 0;
int num = sglen, i;
if (!sgl)
return NULL;
if (zx_pre_config(c, dir))
return NULL;
for_each_sg(sgl, sg, sglen, i) {
avail = sg_dma_len(sg);
if (avail > DMA_MAX_SIZE)
num += DIV_ROUND_UP(avail, DMA_MAX_SIZE) - 1;
}
ds = zx_alloc_desc_resource(num, chan);
if (!ds)
return NULL;
c->cyclic = 0;
num = 0;
for_each_sg(sgl, sg, sglen, i) {
addr = sg_dma_address(sg);
avail = sg_dma_len(sg);
total += avail;
do {
len = min_t(size_t, avail, DMA_MAX_SIZE);
if (dir == DMA_MEM_TO_DEV) {
src = addr;
dst = c->dev_addr;
} else if (dir == DMA_DEV_TO_MEM) {
src = c->dev_addr;
dst = addr;
}
zx_dma_fill_desc(ds, dst, src, len, num++, c->ccfg);
addr += len;
avail -= len;
} while (avail);
}
ds->desc_hw[num - 1].lli = 0; /* end of link */
ds->desc_hw[num - 1].ctr |= ZX_IRQ_ENABLE_ALL;
ds->size = total;
return vchan_tx_prep(&c->vc, &ds->vd, flags);
}
static struct dma_async_tx_descriptor *zx_dma_prep_dma_cyclic(
struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
size_t period_len, enum dma_transfer_direction dir,
unsigned long flags)
{
struct zx_dma_chan *c = to_zx_chan(chan);
struct zx_dma_desc_sw *ds;
dma_addr_t src = 0, dst = 0;
int num_periods = buf_len / period_len;
int buf = 0, num = 0;
if (period_len > DMA_MAX_SIZE) {
dev_err(chan->device->dev, "maximum period size exceeded\n");
return NULL;
}
if (zx_pre_config(c, dir))
return NULL;
ds = zx_alloc_desc_resource(num_periods, chan);
if (!ds)
return NULL;
c->cyclic = 1;
while (buf < buf_len) {
if (dir == DMA_MEM_TO_DEV) {
src = dma_addr;
dst = c->dev_addr;
} else if (dir == DMA_DEV_TO_MEM) {
src = c->dev_addr;
dst = dma_addr;
}
zx_dma_fill_desc(ds, dst, src, period_len, num++,
c->ccfg | ZX_IRQ_ENABLE_ALL);
dma_addr += period_len;
buf += period_len;
}
ds->desc_hw[num - 1].lli = ds->desc_hw_lli;
ds->size = buf_len;
return vchan_tx_prep(&c->vc, &ds->vd, flags);
}
static int zx_dma_config(struct dma_chan *chan,
struct dma_slave_config *cfg)
{
struct zx_dma_chan *c = to_zx_chan(chan);
if (!cfg)
return -EINVAL;
memcpy(&c->slave_cfg, cfg, sizeof(*cfg));
return 0;
}
static int zx_dma_terminate_all(struct dma_chan *chan)
{
struct zx_dma_chan *c = to_zx_chan(chan);
struct zx_dma_dev *d = to_zx_dma(chan->device);
struct zx_dma_phy *p = c->phy;
unsigned long flags;
LIST_HEAD(head);
dev_dbg(d->slave.dev, "vchan %p: terminate all\n", &c->vc);
/* Prevent this channel being scheduled */
spin_lock(&d->lock);
list_del_init(&c->node);
spin_unlock(&d->lock);
/* Clear the tx descriptor lists */
spin_lock_irqsave(&c->vc.lock, flags);
vchan_get_all_descriptors(&c->vc, &head);
if (p) {
/* vchan is assigned to a pchan - stop the channel */
zx_dma_terminate_chan(p, d);
c->phy = NULL;
p->vchan = NULL;
p->ds_run = NULL;
p->ds_done = NULL;
}
spin_unlock_irqrestore(&c->vc.lock, flags);
vchan_dma_desc_free_list(&c->vc, &head);
return 0;
}
static int zx_dma_transfer_pause(struct dma_chan *chan)
{
struct zx_dma_chan *c = to_zx_chan(chan);
u32 val = 0;
val = readl_relaxed(c->phy->base + REG_ZX_CTRL);
val &= ~ZX_CH_ENABLE;
writel_relaxed(val, c->phy->base + REG_ZX_CTRL);
return 0;
}
static int zx_dma_transfer_resume(struct dma_chan *chan)
{
struct zx_dma_chan *c = to_zx_chan(chan);
u32 val = 0;
val = readl_relaxed(c->phy->base + REG_ZX_CTRL);
val |= ZX_CH_ENABLE;
writel_relaxed(val, c->phy->base + REG_ZX_CTRL);
return 0;
}
static void zx_dma_free_desc(struct virt_dma_desc *vd)
{
struct zx_dma_desc_sw *ds =
container_of(vd, struct zx_dma_desc_sw, vd);
struct zx_dma_dev *d = to_zx_dma(vd->tx.chan->device);
dma_pool_free(d->pool, ds->desc_hw, ds->desc_hw_lli);
kfree(ds);
}
static const struct of_device_id zx6702_dma_dt_ids[] = {
{ .compatible = "zte,zx296702-dma", },
{}
};
MODULE_DEVICE_TABLE(of, zx6702_dma_dt_ids);
static struct dma_chan *zx_of_dma_simple_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct zx_dma_dev *d = ofdma->of_dma_data;
unsigned int request = dma_spec->args[0];
struct dma_chan *chan;
struct zx_dma_chan *c;
if (request >= d->dma_requests)
return NULL;
chan = dma_get_any_slave_channel(&d->slave);
if (!chan) {
dev_err(d->slave.dev, "get channel fail in %s.\n", __func__);
return NULL;
}
c = to_zx_chan(chan);
c->id = request;
dev_info(d->slave.dev, "zx_dma: pchan %u: alloc vchan %p\n",
c->id, &c->vc);
return chan;
}
static int zx_dma_probe(struct platform_device *op)
{
struct zx_dma_dev *d;
struct resource *iores;
int i, ret = 0;
iores = platform_get_resource(op, IORESOURCE_MEM, 0);
if (!iores)
return -EINVAL;
d = devm_kzalloc(&op->dev, sizeof(*d), GFP_KERNEL);
if (!d)
return -ENOMEM;
d->base = devm_ioremap_resource(&op->dev, iores);
if (IS_ERR(d->base))
return PTR_ERR(d->base);
of_property_read_u32((&op->dev)->of_node,
"dma-channels", &d->dma_channels);
of_property_read_u32((&op->dev)->of_node,
"dma-requests", &d->dma_requests);
if (!d->dma_requests || !d->dma_channels)
return -EINVAL;
d->clk = devm_clk_get(&op->dev, NULL);
if (IS_ERR(d->clk)) {
dev_err(&op->dev, "no dma clk\n");
return PTR_ERR(d->clk);
}
d->irq = platform_get_irq(op, 0);
ret = devm_request_irq(&op->dev, d->irq, zx_dma_int_handler,
0, DRIVER_NAME, d);
if (ret)
return ret;
/* A DMA memory pool for LLIs, align on 32-byte boundary */
d->pool = dmam_pool_create(DRIVER_NAME, &op->dev,
LLI_BLOCK_SIZE, 32, 0);
if (!d->pool)
return -ENOMEM;
/* init phy channel */
d->phy = devm_kzalloc(&op->dev,
d->dma_channels * sizeof(struct zx_dma_phy), GFP_KERNEL);
if (!d->phy)
return -ENOMEM;
for (i = 0; i < d->dma_channels; i++) {
struct zx_dma_phy *p = &d->phy[i];
p->idx = i;
p->base = d->base + i * 0x40;
}
INIT_LIST_HEAD(&d->slave.channels);
dma_cap_set(DMA_SLAVE, d->slave.cap_mask);
dma_cap_set(DMA_MEMCPY, d->slave.cap_mask);
dma_cap_set(DMA_PRIVATE, d->slave.cap_mask);
d->slave.dev = &op->dev;
d->slave.device_free_chan_resources = zx_dma_free_chan_resources;
d->slave.device_tx_status = zx_dma_tx_status;
d->slave.device_prep_dma_memcpy = zx_dma_prep_memcpy;
d->slave.device_prep_slave_sg = zx_dma_prep_slave_sg;
d->slave.device_prep_dma_cyclic = zx_dma_prep_dma_cyclic;
d->slave.device_issue_pending = zx_dma_issue_pending;
d->slave.device_config = zx_dma_config;
d->slave.device_terminate_all = zx_dma_terminate_all;
d->slave.device_pause = zx_dma_transfer_pause;
d->slave.device_resume = zx_dma_transfer_resume;
d->slave.copy_align = DMA_ALIGN;
d->slave.src_addr_widths = ZX_DMA_BUSWIDTHS;
d->slave.dst_addr_widths = ZX_DMA_BUSWIDTHS;
d->slave.directions = BIT(DMA_MEM_TO_MEM) | BIT(DMA_MEM_TO_DEV)
| BIT(DMA_DEV_TO_MEM);
d->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
/* init virtual channel */
d->chans = devm_kzalloc(&op->dev,
d->dma_requests * sizeof(struct zx_dma_chan), GFP_KERNEL);
if (!d->chans)
return -ENOMEM;
for (i = 0; i < d->dma_requests; i++) {
struct zx_dma_chan *c = &d->chans[i];
c->status = DMA_IN_PROGRESS;
INIT_LIST_HEAD(&c->node);
c->vc.desc_free = zx_dma_free_desc;
vchan_init(&c->vc, &d->slave);
}
/* Enable clock before accessing registers */
ret = clk_prepare_enable(d->clk);
if (ret < 0) {
dev_err(&op->dev, "clk_prepare_enable failed: %d\n", ret);
goto zx_dma_out;
}
zx_dma_init_state(d);
spin_lock_init(&d->lock);
INIT_LIST_HEAD(&d->chan_pending);
platform_set_drvdata(op, d);
ret = dma_async_device_register(&d->slave);
if (ret)
goto clk_dis;
ret = of_dma_controller_register((&op->dev)->of_node,
zx_of_dma_simple_xlate, d);
if (ret)
goto of_dma_register_fail;
dev_info(&op->dev, "initialized\n");
return 0;
of_dma_register_fail:
dma_async_device_unregister(&d->slave);
clk_dis:
clk_disable_unprepare(d->clk);
zx_dma_out:
return ret;
}
static int zx_dma_remove(struct platform_device *op)
{
struct zx_dma_chan *c, *cn;
struct zx_dma_dev *d = platform_get_drvdata(op);
/* explictly free the irq */
devm_free_irq(&op->dev, d->irq, d);
dma_async_device_unregister(&d->slave);
of_dma_controller_free((&op->dev)->of_node);
list_for_each_entry_safe(c, cn, &d->slave.channels,
vc.chan.device_node) {
list_del(&c->vc.chan.device_node);
}
clk_disable_unprepare(d->clk);
dmam_pool_destroy(d->pool);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int zx_dma_suspend_dev(struct device *dev)
{
struct zx_dma_dev *d = dev_get_drvdata(dev);
u32 stat = 0;
stat = zx_dma_get_chan_stat(d);
if (stat) {
dev_warn(d->slave.dev,
"chan %d is running fail to suspend\n", stat);
return -1;
}
clk_disable_unprepare(d->clk);
return 0;
}
static int zx_dma_resume_dev(struct device *dev)
{
struct zx_dma_dev *d = dev_get_drvdata(dev);
int ret = 0;
ret = clk_prepare_enable(d->clk);
if (ret < 0) {
dev_err(d->slave.dev, "clk_prepare_enable failed: %d\n", ret);
return ret;
}
zx_dma_init_state(d);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(zx_dma_pmops, zx_dma_suspend_dev, zx_dma_resume_dev);
static struct platform_driver zx_pdma_driver = {
.driver = {
.name = DRIVER_NAME,
.pm = &zx_dma_pmops,
.of_match_table = zx6702_dma_dt_ids,
},
.probe = zx_dma_probe,
.remove = zx_dma_remove,
};
module_platform_driver(zx_pdma_driver);
MODULE_DESCRIPTION("ZTE ZX296702 DMA Driver");
MODULE_AUTHOR("Jun Nie jun.nie@linaro.org");
MODULE_LICENSE("GPL v2");