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dmaengine: mxs-dma: add dma support for i.MX23/28

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This patch adds dma support for Freescale MXS-based SoC i.MX23/28,
including apbh-dma and apbx-dma.

* apbh-dma and apbx-dma are supported in the driver as two mxs-dma
  instances.

* apbh-dma is different between mx23 and mx28, hardware version
  register is used to differentiate.

* mxs-dma supports pio function besides data transfer.  The driver
  uses dma_data_direction DMA_NONE to identify the pio mode, and
  steals sgl and sg_len to get pio words and numbers from clients.

* mxs dmaengine has some very specific features, like sense function
  and the special NAND support (nand_lock, nand_wait4ready).  These
  are too specific to implemented in generic dmaengine driver.

* The driver refers to imx-sdma and only a single descriptor is
  statically assigned to each channel.

Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Shawn Guo 2011-02-27 00:47:42 +08:00 committed by Vinod Koul
parent 26d890f0d0
commit a580b8c542
4 changed files with 759 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
arch/arm/mach-mxs/include/mach/dma.h Normal file
View File

@ -0,0 +1,26 @@
/*
* Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved.
*
* 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.
*/
#ifndef __MACH_MXS_DMA_H__
#define __MACH_MXS_DMA_H__
struct mxs_dma_data {
int chan_irq;
};
static inline int mxs_dma_is_apbh(struct dma_chan *chan)
{
return !strcmp(dev_name(chan->device->dev), "mxs-dma-apbh");
}
static inline int mxs_dma_is_apbx(struct dma_chan *chan)
{
return !strcmp(dev_name(chan->device->dev), "mxs-dma-apbx");
}
#endif /* __MACH_MXS_DMA_H__ */

8
drivers/dma/Kconfig
View File

@ -227,6 +227,14 @@ config IMX_DMA
Support the i.MX DMA engine. This engine is integrated into
Freescale i.MX1/21/27 chips.
config MXS_DMA
bool "MXS DMA support"
depends on SOC_IMX23 || SOC_IMX28
select DMA_ENGINE
help
Support the MXS DMA engine. This engine including APBH-DMA
and APBX-DMA is integrated into Freescale i.MX23/28 chips.
config DMA_ENGINE
bool

1
drivers/dma/Makefile
View File

@ -23,6 +23,7 @@ obj-$(CONFIG_COH901318) += coh901318.o coh901318_lli.o
obj-$(CONFIG_AMCC_PPC440SPE_ADMA) += ppc4xx/
obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
obj-$(CONFIG_IMX_DMA) += imx-dma.o
obj-$(CONFIG_MXS_DMA) += mxs-dma.o
obj-$(CONFIG_TIMB_DMA) += timb_dma.o
obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
obj-$(CONFIG_PL330_DMA) += pl330.o

724
drivers/dma/mxs-dma.c Normal file
View File

@ -0,0 +1,724 @@
/*
* 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 <asm/irq.h>
#include <mach/mxs.h>
#include <mach/dma.h>
#include <mach/common.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 MXS_DMA_APBH 0
#define MXS_DMA_APBX 1
#define dma_is_apbh() (mxs_dma->dev_id == MXS_DMA_APBH)
#define APBH_VERSION_LATEST 3
#define apbh_is_old() (mxs_dma->version < APBH_VERSION_LATEST)
#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_CLKGATE_CHANNEL 8
#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
#define HW_APBH_VERSION (cpu_is_mx23() ? 0x3f0 : 0x800)
#define HW_APBX_VERSION 0x800
#define BP_APBHX_VERSION_MAJOR 24
#define HW_APBHX_CHn_NXTCMDAR(n) \
(((dma_is_apbh() && apbh_is_old()) ? 0x050 : 0x110) + (n) * 0x70)
#define HW_APBHX_CHn_SEMA(n) \
(((dma_is_apbh() && apbh_is_old()) ? 0x080 : 0x140) + (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 NUM_CCW (int)(PAGE_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;
int chan_irq;
struct mxs_dma_ccw *ccw;
dma_addr_t ccw_phys;
dma_cookie_t last_completed;
enum dma_status status;
unsigned int flags;
#define MXS_DMA_SG_LOOP (1 << 0)
};
#define MXS_DMA_CHANNELS 16
#define MXS_DMA_CHANNELS_MASK 0xffff
struct mxs_dma_engine {
int dev_id;
unsigned int version;
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];
};
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;
if (dma_is_apbh() && apbh_is_old())
writel(1 << (chan_id + BP_APBH_CTRL0_RESET_CHANNEL),
mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
else
writel(1 << (chan_id + BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL),
mxs_dma->base + HW_APBHX_CHANNEL_CTRL + MXS_SET_ADDR);
}
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(chan_id));
/* enable apbh channel clock */
if (dma_is_apbh()) {
if (apbh_is_old())
writel(1 << (chan_id + BP_APBH_CTRL0_CLKGATE_CHANNEL),
mxs_dma->base + HW_APBHX_CTRL0 + MXS_CLR_ADDR);
else
writel(1 << chan_id,
mxs_dma->base + HW_APBHX_CTRL0 + MXS_CLR_ADDR);
}
/* write 1 to SEMA to kick off the channel */
writel(1, mxs_dma->base + HW_APBHX_CHn_SEMA(chan_id));
}
static void mxs_dma_disable_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;
/* disable apbh channel clock */
if (dma_is_apbh()) {
if (apbh_is_old())
writel(1 << (chan_id + BP_APBH_CTRL0_CLKGATE_CHANNEL),
mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
else
writel(1 << chan_id,
mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
}
mxs_chan->status = DMA_SUCCESS;
}
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() && apbh_is_old())
writel(1 << chan_id,
mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
else
writel(1 << chan_id,
mxs_dma->base + HW_APBHX_CHANNEL_CTRL + MXS_SET_ADDR);
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() && apbh_is_old())
writel(1 << chan_id,
mxs_dma->base + HW_APBHX_CTRL0 + MXS_CLR_ADDR);
else
writel(1 << chan_id,
mxs_dma->base + HW_APBHX_CHANNEL_CTRL + MXS_CLR_ADDR);
mxs_chan->status = DMA_IN_PROGRESS;
}
static dma_cookie_t mxs_dma_assign_cookie(struct mxs_dma_chan *mxs_chan)
{
dma_cookie_t cookie = mxs_chan->chan.cookie;
if (++cookie < 0)
cookie = 1;
mxs_chan->chan.cookie = cookie;
mxs_chan->desc.cookie = cookie;
return cookie;
}
static struct mxs_dma_chan *to_mxs_dma_chan(struct dma_chan *chan)
{
return container_of(chan, struct mxs_dma_chan, chan);
}
static dma_cookie_t mxs_dma_tx_submit(struct dma_async_tx_descriptor *tx)
{
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(tx->chan);
mxs_dma_enable_chan(mxs_chan);
return mxs_dma_assign_cookie(mxs_chan);
}
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 irqreturn_t mxs_dma_int_handler(int irq, void *dev_id)
{
struct mxs_dma_engine *mxs_dma = dev_id;
u32 stat1, stat2;
/* completion status */
stat1 = readl(mxs_dma->base + HW_APBHX_CTRL1);
stat1 &= MXS_DMA_CHANNELS_MASK;
writel(stat1, mxs_dma->base + HW_APBHX_CTRL1 + MXS_CLR_ADDR);
/* error status */
stat2 = readl(mxs_dma->base + HW_APBHX_CTRL2);
writel(stat2, mxs_dma->base + HW_APBHX_CTRL2 + MXS_CLR_ADDR);
/*
* 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 handler here in case of ether it's (1) an bus
* error or (2) a termination error with no completion.
*/
stat2 = ((stat2 >> MXS_DMA_CHANNELS) & stat2) | /* (1) */
(~(stat2 >> MXS_DMA_CHANNELS) & stat2 & ~stat1); /* (2) */
/* combine error and completion status for checking */
stat1 = (stat2 << MXS_DMA_CHANNELS) | stat1;
while (stat1) {
int channel = fls(stat1) - 1;
struct mxs_dma_chan *mxs_chan =
&mxs_dma->mxs_chans[channel % MXS_DMA_CHANNELS];
if (channel >= MXS_DMA_CHANNELS) {
dev_dbg(mxs_dma->dma_device.dev,
"%s: error in channel %d\n", __func__,
channel - MXS_DMA_CHANNELS);
mxs_chan->status = DMA_ERROR;
mxs_dma_reset_chan(mxs_chan);
} else {
if (mxs_chan->flags & MXS_DMA_SG_LOOP)
mxs_chan->status = DMA_IN_PROGRESS;
else
mxs_chan->status = DMA_SUCCESS;
}
stat1 &= ~(1 << channel);
if (mxs_chan->status == DMA_SUCCESS)
mxs_chan->last_completed = mxs_chan->desc.cookie;
/* 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_data *data = chan->private;
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int ret;
if (!data)
return -EINVAL;
mxs_chan->chan_irq = data->chan_irq;
mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,
&mxs_chan->ccw_phys, GFP_KERNEL);
if (!mxs_chan->ccw) {
ret = -ENOMEM;
goto err_alloc;
}
memset(mxs_chan->ccw, 0, PAGE_SIZE);
ret = request_irq(mxs_chan->chan_irq, mxs_dma_int_handler,
0, "mxs-dma", mxs_dma);
if (ret)
goto err_irq;
ret = clk_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, PAGE_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, PAGE_SIZE,
mxs_chan->ccw, mxs_chan->ccw_phys);
clk_disable(mxs_dma->clk);
}
static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_data_direction direction,
unsigned long append)
{
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;
int i, j;
u32 *pio;
static int idx;
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;
ccw->bits &= ~CCW_WAIT4END;
} else {
idx = 0;
}
if (direction == DMA_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;
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->length > MAX_XFER_BYTES) {
dev_err(mxs_dma->dma_device.dev, "maximum bytes for sg entry exceeded: %d > %d\n",
sg->length, 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->length;
ccw->bits = 0;
ccw->bits |= CCW_CHAIN;
ccw->bits |= CCW_HALT_ON_TERM;
ccw->bits |= CCW_TERM_FLUSH;
ccw->bits |= BF_CCW(direction == DMA_FROM_DEVICE ?
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;
ccw->bits |= CCW_WAIT4END;
}
}
}
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_data_direction direction)
{
struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
int num_periods = buf_len / period_len;
int 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;
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 |= BF_CCW(direction == DMA_FROM_DEVICE ?
MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ, COMMAND);
dma_addr += period_len;
buf += period_len;
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_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);
dma_cookie_t last_used;
last_used = chan->cookie;
dma_set_tx_state(txstate, mxs_chan->last_completed, last_used, 0);
return mxs_chan->status;
}
static void mxs_dma_issue_pending(struct dma_chan *chan)
{
/*
* Nothing to do. We only have a single descriptor.
*/
}
static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
{
int ret;
ret = clk_enable(mxs_dma->clk);
if (ret)
goto err_out;
ret = mxs_reset_block(mxs_dma->base);
if (ret)
goto err_out;
/* only major version matters */
mxs_dma->version = readl(mxs_dma->base +
((mxs_dma->dev_id == MXS_DMA_APBX) ?
HW_APBX_VERSION : HW_APBH_VERSION)) >>
BP_APBHX_VERSION_MAJOR;
/* enable apbh burst */
if (dma_is_apbh()) {
writel(BM_APBH_CTRL0_APB_BURST_EN,
mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
writel(BM_APBH_CTRL0_APB_BURST8_EN,
mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
}
/* enable irq for all the channels */
writel(MXS_DMA_CHANNELS_MASK << MXS_DMA_CHANNELS,
mxs_dma->base + HW_APBHX_CTRL1 + MXS_SET_ADDR);
clk_disable(mxs_dma->clk);
return 0;
err_out:
return ret;
}
static int __init mxs_dma_probe(struct platform_device *pdev)
{
const struct platform_device_id *id_entry =
platform_get_device_id(pdev);
struct mxs_dma_engine *mxs_dma;
struct resource *iores;
int ret, i;
mxs_dma = kzalloc(sizeof(*mxs_dma), GFP_KERNEL);
if (!mxs_dma)
return -ENOMEM;
mxs_dma->dev_id = id_entry->driver_data;
iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!request_mem_region(iores->start, resource_size(iores),
pdev->name)) {
ret = -EBUSY;
goto err_request_region;
}
mxs_dma->base = ioremap(iores->start, resource_size(iores));
if (!mxs_dma->base) {
ret = -ENOMEM;
goto err_ioremap;
}
mxs_dma->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(mxs_dma->clk)) {
ret = PTR_ERR(mxs_dma->clk);
goto err_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;
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)
goto err_init;
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");
goto err_init;
}
dev_info(mxs_dma->dma_device.dev, "initialized\n");
return 0;
err_init:
clk_put(mxs_dma->clk);
err_clk:
iounmap(mxs_dma->base);
err_ioremap:
release_mem_region(iores->start, resource_size(iores));
err_request_region:
kfree(mxs_dma);
return ret;
}
static struct platform_device_id mxs_dma_type[] = {
{
.name = "mxs-dma-apbh",
.driver_data = MXS_DMA_APBH,
}, {
.name = "mxs-dma-apbx",
.driver_data = MXS_DMA_APBX,
}
};
static struct platform_driver mxs_dma_driver = {
.driver = {
.name = "mxs-dma",
},
.id_table = mxs_dma_type,
};
static int __init mxs_dma_module_init(void)
{
return platform_driver_probe(&mxs_dma_driver, mxs_dma_probe);
}
subsys_initcall(mxs_dma_module_init);