- 根目录:
- drivers
- dma
- mxs-dma.c
/*
* Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved.
*
* Refer to drivers/dma/imx-sdma.c
*
* 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/init.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/semaphore.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/dmaengine.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/stmp_device.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_dma.h>
#include <linux/list.h>
#include <asm/irq.h>
#include "dmaengine.h"
/*
* NOTE: The term "PIO" throughout the mxs-dma implementation means
* PIO mode of mxs apbh-dma and apbx-dma. With this working mode,
* dma can program the controller registers of peripheral devices.
*/
#define dma_is_apbh(mxs_dma) ((mxs_dma)->type == MXS_DMA_APBH)
#define apbh_is_old(mxs_dma) ((mxs_dma)->dev_id == IMX23_DMA)
#define HW_APBHX_CTRL0 0x000
#define BM_APBH_CTRL0_APB_BURST8_EN (1 << 29)
#define BM_APBH_CTRL0_APB_BURST_EN (1 << 28)
#define BP_APBH_CTRL0_RESET_CHANNEL 16
#define HW_APBHX_CTRL1 0x010
#define HW_APBHX_CTRL2 0x020
#define HW_APBHX_CHANNEL_CTRL 0x030
#define BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL 16
/*
* The offset of NXTCMDAR register is different per both dma type and version,
* while stride for each channel is all the same 0x70.
*/
#define HW_APBHX_CHn_NXTCMDAR(d, n) \
(((dma_is_apbh(d) && apbh_is_old(d)) ? 0x050 : 0x110) + (n) * 0x70)
#define HW_APBHX_CHn_SEMA(d, n) \
(((dma_is_apbh(d) && apbh_is_old(d)) ? 0x080 : 0x140) + (n) * 0x70)
#define HW_APBHX_CHn_BAR(d, n) \
(((dma_is_apbh(d) && apbh_is_old(d)) ? 0x070 : 0x130) + (n) * 0x70)
#define HW_APBX_CHn_DEBUG1(d, n) (0x150 + (n) * 0x70)
/*
* ccw bits definitions
*
* COMMAND: 0..1 (2)
* CHAIN: 2 (1)
* IRQ: 3 (1)
* NAND_LOCK: 4 (1) - not implemented
* NAND_WAIT4READY: 5 (1) - not implemented
* DEC_SEM: 6 (1)
* WAIT4END: 7 (1)
* HALT_ON_TERMINATE: 8 (1)
* TERMINATE_FLUSH: 9 (1)
* RESERVED: 10..11 (2)
* PIO_NUM: 12..15 (4)
*/
#define BP_CCW_COMMAND 0
#define BM_CCW_COMMAND (3 << 0)
#define CCW_CHAIN (1 << 2)
#define CCW_IRQ (1 << 3)
#define CCW_DEC_SEM (1 << 6)
#define CCW_WAIT4END (1 << 7)
#define CCW_HALT_ON_TERM (1 << 8)
#define CCW_TERM_FLUSH (1 << 9)
#define BP_CCW_PIO_NUM 12
#define BM_CCW_PIO_NUM (0xf << 12)
#define BF_CCW(value, field) (((value) << BP_CCW_##field) & BM_CCW_##field)
#define MXS_DMA_CMD_NO_XFER 0
#define MXS_DMA_CMD_WRITE 1
#define MXS_DMA_CMD_READ 2
#define MXS_DMA_CMD_DMA_SENSE 3 /* not implemented */
struct mxs_dma_ccw {
u32 next;
u16 bits;
u16 xfer_bytes;
#define MAX_XFER_BYTES 0xff00
u32 bufaddr;
#define MXS_PIO_WORDS 16
u32 pio_words[MXS_PIO_WORDS];
};
#define CCW_BLOCK_SIZE (4 * PAGE_SIZE)
#define NUM_CCW (int)(CCW_BLOCK_SIZE / sizeof(struct mxs_dma_ccw))
struct mxs_dma_chan {
struct mxs_dma_engine *mxs_dma;
struct dma_chan chan;
struct dma_async_tx_descriptor desc;
struct tasklet_struct tasklet;
unsigned int chan_irq;
struct mxs_dma_ccw *ccw;
dma_addr_t ccw_phys;
int desc_count;
enum dma_status status;
unsigned int flags;
bool reset;
#define MXS_DMA_SG_LOOP (1 << 0)
#define MXS_DMA_USE_SEMAPHORE (1 << 1)
};
#define MXS_DMA_CHANNELS 16
#define MXS_DMA_CHANNELS_MASK 0xffff
enum mxs_dma_devtype {
MXS_DMA_APBH,
MXS_DMA_APBX,
};
enum mxs_dma_id {
IMX23_DMA,
IMX28_DMA,
};
struct mxs_dma_engine {
enum mxs_dma_id dev_id;
enum mxs_dma_devtype type;
void __iomem *base;
struct clk *clk;
struct dma_device dma_device;
struct device_dma_parameters dma_parms;
struct mxs_dma_chan mxs_chans[MXS_DMA_CHANNELS];
struct platform_device *pdev;
unsigned int nr_channels;
};
struct mxs_dma_type {
enum mxs_dma_id id;
enum mxs_dma_devtype type;
};
static struct mxs_dma_type mxs_dma_types[] = {
{
.id = IMX23_DMA,
.type = MXS_DMA_APBH,
}, {
.id = IMX23_DMA,
.type = MXS_DMA_APBX,
}, {
.id = IMX28_DMA,
.type = MXS_DMA_APBH,
}, {
.id = IMX28_DMA,
.type = MXS_DMA_APBX,
}
};
static struct platform_device_id mxs_dma_ids[] = {
{
.name = "imx23-dma-apbh",
.driver_data = (kernel_ulong_t) &mxs_dma_types[0],
}, {
.name = "imx23-dma-apbx",
.driver_data = (kernel_ulong_t) &mxs_dma_types[1],
}, {
.name = "imx28-dma-apbh",
.driver_data = (kernel_ulong_t) &mxs_dma_types[2],
}, {
.name = "imx28-dma-apbx",
.driver_data = (kernel_ulong_t) &mxs_dma_types[3],
}, {
/* end of list */
}
};
static const struct of_device_id mxs_dma_dt_ids[] = {
{ .compatible = "fsl,imx23-dma-apbh", .data = &mxs_dma_ids[0], },
{ .compatible = "fsl,imx23-dma-apbx", .data = &mxs_dma_ids[1], },
{ .compatible = "fsl,imx28-dma-apbh", .data = &mxs_dma_ids[2], },
{ .compatible = "fsl,imx28-dma-apbx", .data = &mxs_dma_ids[3], },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mxs_dma_dt_ids);
static struct mxs_dma_chan *to_mxs_dma_chan(struct dma_chan *chan)
{
return container_of(chan, struct mxs_dma_chan, chan);
}
static void mxs_dma_reset_chan(struct mxs_dma_chan *mxs_chan)
{
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int chan_id = mxs_chan->chan.chan_id;
/*
* mxs dma channel resets can cause a channel stall. To recover from a
* channel stall, we have to reset the whole DMA engine. To avoid this,
* we use cyclic DMA with semaphores, that are enhanced in
* mxs_dma_int_handler. To reset the channel, we can simply stop writing
* into the semaphore counter.
*/
if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE &&
mxs_chan->flags & MXS_DMA_SG_LOOP) {
mxs_chan->reset = true;
} else if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma)) {
writel(1 << (chan_id + BP_APBH_CTRL0_RESET_CHANNEL),
mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
} else {
unsigned long elapsed = 0;
const unsigned long max_wait = 50000; /* 50ms */
void __iomem *reg_dbg1 = mxs_dma->base +
HW_APBX_CHn_DEBUG1(mxs_dma, chan_id);
/*
* On i.MX28 APBX, the DMA channel can stop working if we reset
* the channel while it is in READ_FLUSH (0x08) state.
* We wait here until we leave the state. Then we trigger the
* reset. Waiting a maximum of 50ms, the kernel shouldn't crash
* because of this.
*/
while ((readl(reg_dbg1) & 0xf) == 0x8 && elapsed < max_wait) {
udelay(100);
elapsed += 100;
}
if (elapsed >= max_wait)
dev_err(&mxs_chan->mxs_dma->pdev->dev,
"Failed waiting for the DMA channel %d to leave state READ_FLUSH, trying to reset channel in READ_FLUSH state now\n",
chan_id);
writel(1 << (chan_id + BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL),
mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_SET);
}
mxs_chan->status = DMA_COMPLETE;
}
static void mxs_dma_enable_chan(struct mxs_dma_chan *mxs_chan)
{
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int chan_id = mxs_chan->chan.chan_id;
/* set cmd_addr up */
writel(mxs_chan->ccw_phys,
mxs_dma->base + HW_APBHX_CHn_NXTCMDAR(mxs_dma, chan_id));
/* write 1 to SEMA to kick off the channel */
if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE &&
mxs_chan->flags & MXS_DMA_SG_LOOP) {
/* A cyclic DMA consists of at least 2 segments, so initialize
* the semaphore with 2 so we have enough time to add 1 to the
* semaphore if we need to */
writel(2, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan_id));
} else {
writel(1, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan_id));
}
mxs_chan->reset = false;
}
static void mxs_dma_disable_chan(struct mxs_dma_chan *mxs_chan)
{
mxs_chan->status = DMA_COMPLETE;
}
static void mxs_dma_pause_chan(struct mxs_dma_chan *mxs_chan)
{
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int chan_id = mxs_chan->chan.chan_id;
/* freeze the channel */
if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma))
writel(1 << chan_id,
mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
else
writel(1 << chan_id,
mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_SET);
mxs_chan->status = DMA_PAUSED;
}
static void mxs_dma_resume_chan(struct mxs_dma_chan *mxs_chan)
{
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int chan_id = mxs_chan->chan.chan_id;
/* unfreeze the channel */
if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma))
writel(1 << chan_id,
mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_CLR);
else
writel(1 << chan_id,
mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_CLR);
mxs_chan->status = DMA_IN_PROGRESS;
}
static dma_cookie_t mxs_dma_tx_submit(struct dma_async_tx_descriptor *tx)
{
return dma_cookie_assign(tx);
}
static void mxs_dma_tasklet(unsigned long data)
{
struct mxs_dma_chan *mxs_chan = (struct mxs_dma_chan *) data;
if (mxs_chan->desc.callback)
mxs_chan->desc.callback(mxs_chan->desc.callback_param);
}
static int mxs_dma_irq_to_chan(struct mxs_dma_engine *mxs_dma, int irq)
{
int i;
for (i = 0; i != mxs_dma->nr_channels; ++i)
if (mxs_dma->mxs_chans[i].chan_irq == irq)
return i;
return -EINVAL;
}
static irqreturn_t mxs_dma_int_handler(int irq, void *dev_id)
{
struct mxs_dma_engine *mxs_dma = dev_id;
struct mxs_dma_chan *mxs_chan;
u32 completed;
u32 err;
int chan = mxs_dma_irq_to_chan(mxs_dma, irq);
if (chan < 0)
return IRQ_NONE;
/* completion status */
completed = readl(mxs_dma->base + HW_APBHX_CTRL1);
completed = (completed >> chan) & 0x1;
/* Clear interrupt */
writel((1 << chan),
mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_CLR);
/* error status */
err = readl(mxs_dma->base + HW_APBHX_CTRL2);
err &= (1 << (MXS_DMA_CHANNELS + chan)) | (1 << chan);
/*
* error status bit is in the upper 16 bits, error irq bit in the lower
* 16 bits. We transform it into a simpler error code:
* err: 0x00 = no error, 0x01 = TERMINATION, 0x02 = BUS_ERROR
*/
err = (err >> (MXS_DMA_CHANNELS + chan)) + (err >> chan);
/* Clear error irq */
writel((1 << chan),
mxs_dma->base + HW_APBHX_CTRL2 + STMP_OFFSET_REG_CLR);
/*
* When both completion and error of termination bits set at the
* same time, we do not take it as an error. IOW, it only becomes
* an error we need to handle here in case of either it's a bus
* error or a termination error with no completion. 0x01 is termination
* error, so we can subtract err & completed to get the real error case.
*/
err -= err & completed;
mxs_chan = &mxs_dma->mxs_chans[chan];
if (err) {
dev_dbg(mxs_dma->dma_device.dev,
"%s: error in channel %d\n", __func__,
chan);
mxs_chan->status = DMA_ERROR;
mxs_dma_reset_chan(mxs_chan);
} else if (mxs_chan->status != DMA_COMPLETE) {
if (mxs_chan->flags & MXS_DMA_SG_LOOP) {
mxs_chan->status = DMA_IN_PROGRESS;
if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE)
writel(1, mxs_dma->base +
HW_APBHX_CHn_SEMA(mxs_dma, chan));
} else {
mxs_chan->status = DMA_COMPLETE;
}
}
if (mxs_chan->status == DMA_COMPLETE) {
if (mxs_chan->reset)
return IRQ_HANDLED;
dma_cookie_complete(&mxs_chan->desc);
}
/* schedule tasklet on this channel */
tasklet_schedule(&mxs_chan->tasklet);
return IRQ_HANDLED;
}
static int mxs_dma_alloc_chan_resources(struct dma_chan *chan)
{
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int ret;
mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev,
CCW_BLOCK_SIZE, &mxs_chan->ccw_phys,
GFP_KERNEL);
if (!mxs_chan->ccw) {
ret = -ENOMEM;
goto err_alloc;
}
memset(mxs_chan->ccw, 0, CCW_BLOCK_SIZE);
if (mxs_chan->chan_irq != NO_IRQ) {
ret = request_irq(mxs_chan->chan_irq, mxs_dma_int_handler,
0, "mxs-dma", mxs_dma);
if (ret)
goto err_irq;
}
ret = clk_prepare_enable(mxs_dma->clk);
if (ret)
goto err_clk;
mxs_dma_reset_chan(mxs_chan);
dma_async_tx_descriptor_init(&mxs_chan->desc, chan);
mxs_chan->desc.tx_submit = mxs_dma_tx_submit;
/* the descriptor is ready */
async_tx_ack(&mxs_chan->desc);
return 0;
err_clk:
free_irq(mxs_chan->chan_irq, mxs_dma);
err_irq:
dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,
mxs_chan->ccw, mxs_chan->ccw_phys);
err_alloc:
return ret;
}
static void mxs_dma_free_chan_resources(struct dma_chan *chan)
{
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
mxs_dma_disable_chan(mxs_chan);
free_irq(mxs_chan->chan_irq, mxs_dma);
dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,
mxs_chan->ccw, mxs_chan->ccw_phys);
clk_disable_unprepare(mxs_dma->clk);
}
/*
* How to use the flags for ->device_prep_slave_sg() :
* [1] If there is only one DMA command in the DMA chain, the code should be:
* ......
* ->device_prep_slave_sg(DMA_CTRL_ACK);
* ......
* [2] If there are two DMA commands in the DMA chain, the code should be
* ......
* ->device_prep_slave_sg(0);
* ......
* ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
* ......
* [3] If there are more than two DMA commands in the DMA chain, the code
* should be:
* ......
* ->device_prep_slave_sg(0); // First
* ......
* ->device_prep_slave_sg(DMA_PREP_INTERRUPT [| DMA_CTRL_ACK]);
* ......
* ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK); // Last
* ......
*/
static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction direction,
unsigned long flags, void *context)
{
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
struct mxs_dma_ccw *ccw;
struct scatterlist *sg;
u32 i, j;
u32 *pio;
bool append = flags & DMA_PREP_INTERRUPT;
int idx = append ? mxs_chan->desc_count : 0;
if (mxs_chan->status == DMA_IN_PROGRESS && !append)
return NULL;
if (sg_len + (append ? idx : 0) > NUM_CCW) {
dev_err(mxs_dma->dma_device.dev,
"maximum number of sg exceeded: %d > %d\n",
sg_len, NUM_CCW);
goto err_out;
}
mxs_chan->status = DMA_IN_PROGRESS;
mxs_chan->flags = 0;
/*
* If the sg is prepared with append flag set, the sg
* will be appended to the last prepared sg.
*/
if (append) {
BUG_ON(idx < 1);
ccw = &mxs_chan->ccw[idx - 1];
ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx;
ccw->bits |= CCW_CHAIN;
ccw->bits &= ~CCW_IRQ;
ccw->bits &= ~CCW_DEC_SEM;
} else {
idx = 0;
}
if (direction == DMA_TRANS_NONE) {
ccw = &mxs_chan->ccw[idx++];
pio = (u32 *) sgl;
for (j = 0; j < sg_len;)
ccw->pio_words[j++] = *pio++;
ccw->bits = 0;
ccw->bits |= CCW_IRQ;
ccw->bits |= CCW_DEC_SEM;
if (flags & DMA_CTRL_ACK)
ccw->bits |= CCW_WAIT4END;
ccw->bits |= CCW_HALT_ON_TERM;
ccw->bits |= CCW_TERM_FLUSH;
ccw->bits |= BF_CCW(sg_len, PIO_NUM);
ccw->bits |= BF_CCW(MXS_DMA_CMD_NO_XFER, COMMAND);
} else {
for_each_sg(sgl, sg, sg_len, i) {
if (sg_dma_len(sg) > MAX_XFER_BYTES) {
dev_err(mxs_dma->dma_device.dev, "maximum bytes for sg entry exceeded: %d > %d\n",
sg_dma_len(sg), MAX_XFER_BYTES);
goto err_out;
}
ccw = &mxs_chan->ccw[idx++];
ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx;
ccw->bufaddr = sg->dma_address;
ccw->xfer_bytes = sg_dma_len(sg);
ccw->bits = 0;
ccw->bits |= CCW_CHAIN;
ccw->bits |= CCW_HALT_ON_TERM;
ccw->bits |= CCW_TERM_FLUSH;
ccw->bits |= BF_CCW(direction == DMA_DEV_TO_MEM ?
MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ,
COMMAND);
if (i + 1 == sg_len) {
ccw->bits &= ~CCW_CHAIN;
ccw->bits |= CCW_IRQ;
ccw->bits |= CCW_DEC_SEM;
if (flags & DMA_CTRL_ACK)
ccw->bits |= CCW_WAIT4END;
}
}
}
mxs_chan->desc_count = idx;
return &mxs_chan->desc;
err_out:
mxs_chan->status = DMA_ERROR;
return NULL;
}
static struct dma_async_tx_descriptor *mxs_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 direction,
unsigned long flags, void *context)
{
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
u32 num_periods = buf_len / period_len;
u32 i = 0, buf = 0;
if (mxs_chan->status == DMA_IN_PROGRESS)
return NULL;
mxs_chan->status = DMA_IN_PROGRESS;
mxs_chan->flags |= MXS_DMA_SG_LOOP;
mxs_chan->flags |= MXS_DMA_USE_SEMAPHORE;
if (num_periods > NUM_CCW) {
dev_err(mxs_dma->dma_device.dev,
"maximum number of sg exceeded: %d > %d\n",
num_periods, NUM_CCW);
goto err_out;
}
if (period_len > MAX_XFER_BYTES) {
dev_err(mxs_dma->dma_device.dev,
"maximum period size exceeded: %d > %d\n",
period_len, MAX_XFER_BYTES);
goto err_out;
}
while (buf < buf_len) {
struct mxs_dma_ccw *ccw = &mxs_chan->ccw[i];
if (i + 1 == num_periods)
ccw->next = mxs_chan->ccw_phys;
else
ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * (i + 1);
ccw->bufaddr = dma_addr;
ccw->xfer_bytes = period_len;
ccw->bits = 0;
ccw->bits |= CCW_CHAIN;
ccw->bits |= CCW_IRQ;
ccw->bits |= CCW_HALT_ON_TERM;
ccw->bits |= CCW_TERM_FLUSH;
ccw->bits |= CCW_DEC_SEM;
ccw->bits |= BF_CCW(direction == DMA_DEV_TO_MEM ?
MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ, COMMAND);
dma_addr += period_len;
buf += period_len;
i++;
}
mxs_chan->desc_count = i;
return &mxs_chan->desc;
err_out:
mxs_chan->status = DMA_ERROR;
return NULL;
}
static int mxs_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
int ret = 0;
switch (cmd) {
case DMA_TERMINATE_ALL:
mxs_dma_reset_chan(mxs_chan);
mxs_dma_disable_chan(mxs_chan);
break;
case DMA_PAUSE:
mxs_dma_pause_chan(mxs_chan);
break;
case DMA_RESUME:
mxs_dma_resume_chan(mxs_chan);
break;
default:
ret = -ENOSYS;
}
return ret;
}
static enum dma_status mxs_dma_tx_status(struct dma_chan *chan,
dma_cookie_t cookie, struct dma_tx_state *txstate)
{
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
u32 residue = 0;
if (mxs_chan->status == DMA_IN_PROGRESS &&
mxs_chan->flags & MXS_DMA_SG_LOOP) {
struct mxs_dma_ccw *last_ccw;
u32 bar;
last_ccw = &mxs_chan->ccw[mxs_chan->desc_count - 1];
residue = last_ccw->xfer_bytes + last_ccw->bufaddr;
bar = readl(mxs_dma->base +
HW_APBHX_CHn_BAR(mxs_dma, chan->chan_id));
residue -= bar;
}
dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie,
residue);
return mxs_chan->status;
}
static void mxs_dma_issue_pending(struct dma_chan *chan)
{
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
mxs_dma_enable_chan(mxs_chan);
}
static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
{
int ret;
ret = clk_prepare_enable(mxs_dma->clk);
if (ret)
return ret;
ret = stmp_reset_block(mxs_dma->base);
if (ret)
goto err_out;
/* enable apbh burst */
if (dma_is_apbh(mxs_dma)) {
writel(BM_APBH_CTRL0_APB_BURST_EN,
mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
writel(BM_APBH_CTRL0_APB_BURST8_EN,
mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
}
/* enable irq for all the channels */
writel(MXS_DMA_CHANNELS_MASK << MXS_DMA_CHANNELS,
mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_SET);
err_out:
clk_disable_unprepare(mxs_dma->clk);
return ret;
}
struct mxs_dma_filter_param {
struct device_node *of_node;
unsigned int chan_id;
};
static bool mxs_dma_filter_fn(struct dma_chan *chan, void *fn_param)
{
struct mxs_dma_filter_param *param = fn_param;
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int chan_irq;
if (mxs_dma->dma_device.dev->of_node != param->of_node)
return false;
if (chan->chan_id != param->chan_id)
return false;
chan_irq = platform_get_irq(mxs_dma->pdev, param->chan_id);
if (chan_irq < 0)
return false;
mxs_chan->chan_irq = chan_irq;
return true;
}
static struct dma_chan *mxs_dma_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct mxs_dma_engine *mxs_dma = ofdma->of_dma_data;
dma_cap_mask_t mask = mxs_dma->dma_device.cap_mask;
struct mxs_dma_filter_param param;
if (dma_spec->args_count != 1)
return NULL;
param.of_node = ofdma->of_node;
param.chan_id = dma_spec->args[0];
if (param.chan_id >= mxs_dma->nr_channels)
return NULL;
return dma_request_channel(mask, mxs_dma_filter_fn, ¶m);
}
static int __init mxs_dma_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
const struct platform_device_id *id_entry;
const struct of_device_id *of_id;
const struct mxs_dma_type *dma_type;
struct mxs_dma_engine *mxs_dma;
struct resource *iores;
int ret, i;
mxs_dma = devm_kzalloc(&pdev->dev, sizeof(*mxs_dma), GFP_KERNEL);
if (!mxs_dma)
return -ENOMEM;
ret = of_property_read_u32(np, "dma-channels", &mxs_dma->nr_channels);
if (ret) {
dev_err(&pdev->dev, "failed to read dma-channels\n");
return ret;
}
of_id = of_match_device(mxs_dma_dt_ids, &pdev->dev);
if (of_id)
id_entry = of_id->data;
else
id_entry = platform_get_device_id(pdev);
dma_type = (struct mxs_dma_type *)id_entry->driver_data;
mxs_dma->type = dma_type->type;
mxs_dma->dev_id = dma_type->id;
iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mxs_dma->base = devm_ioremap_resource(&pdev->dev, iores);
if (IS_ERR(mxs_dma->base))
return PTR_ERR(mxs_dma->base);
mxs_dma->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(mxs_dma->clk))
return PTR_ERR(mxs_dma->clk);
dma_cap_set(DMA_SLAVE, mxs_dma->dma_device.cap_mask);
dma_cap_set(DMA_CYCLIC, mxs_dma->dma_device.cap_mask);
INIT_LIST_HEAD(&mxs_dma->dma_device.channels);
/* Initialize channel parameters */
for (i = 0; i < MXS_DMA_CHANNELS; i++) {
struct mxs_dma_chan *mxs_chan = &mxs_dma->mxs_chans[i];
mxs_chan->mxs_dma = mxs_dma;
mxs_chan->chan.device = &mxs_dma->dma_device;
dma_cookie_init(&mxs_chan->chan);
tasklet_init(&mxs_chan->tasklet, mxs_dma_tasklet,
(unsigned long) mxs_chan);
/* Add the channel to mxs_chan list */
list_add_tail(&mxs_chan->chan.device_node,
&mxs_dma->dma_device.channels);
}
ret = mxs_dma_init(mxs_dma);
if (ret)
return ret;
mxs_dma->pdev = pdev;
mxs_dma->dma_device.dev = &pdev->dev;
/* mxs_dma gets 65535 bytes maximum sg size */
mxs_dma->dma_device.dev->dma_parms = &mxs_dma->dma_parms;
dma_set_max_seg_size(mxs_dma->dma_device.dev, MAX_XFER_BYTES);
mxs_dma->dma_device.device_alloc_chan_resources = mxs_dma_alloc_chan_resources;
mxs_dma->dma_device.device_free_chan_resources = mxs_dma_free_chan_resources;
mxs_dma->dma_device.device_tx_status = mxs_dma_tx_status;
mxs_dma->dma_device.device_prep_slave_sg = mxs_dma_prep_slave_sg;
mxs_dma->dma_device.device_prep_dma_cyclic = mxs_dma_prep_dma_cyclic;
mxs_dma->dma_device.device_control = mxs_dma_control;
mxs_dma->dma_device.device_issue_pending = mxs_dma_issue_pending;
ret = dma_async_device_register(&mxs_dma->dma_device);
if (ret) {
dev_err(mxs_dma->dma_device.dev, "unable to register\n");
return ret;
}
ret = of_dma_controller_register(np, mxs_dma_xlate, mxs_dma);
if (ret) {
dev_err(mxs_dma->dma_device.dev,
"failed to register controller\n");
dma_async_device_unregister(&mxs_dma->dma_device);
}
dev_info(mxs_dma->dma_device.dev, "initialized\n");
return 0;
}
static struct platform_driver mxs_dma_driver = {
.driver = {
.name = "mxs-dma",
.of_match_table = mxs_dma_dt_ids,
},
.id_table = mxs_dma_ids,
};
static int __init mxs_dma_module_init(void)
{
return platform_driver_probe(&mxs_dma_driver, mxs_dma_probe);
}
subsys_initcall(mxs_dma_module_init);