Linux-2.6.33.2/arch/arm/plat-mxc/dma-mx1-mx2.c
/*
* linux/arch/arm/plat-mxc/dma-mx1-mx2.c
*
* i.MX DMA registration and IRQ dispatching
*
* Copyright 2006 Pavel Pisa <pisa@cmp.felk.cvut.cz>
* Copyright 2008 Juergen Beisert, <kernel@pengutronix.de>
* Copyright 2008 Sascha Hauer, <s.hauer@pengutronix.de>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/clk.h>
#include <linux/scatterlist.h>
#include <linux/io.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <mach/hardware.h>
#include <mach/dma-mx1-mx2.h>
#define DMA_DCR 0x00 /* Control Register */
#define DMA_DISR 0x04 /* Interrupt status Register */
#define DMA_DIMR 0x08 /* Interrupt mask Register */
#define DMA_DBTOSR 0x0c /* Burst timeout status Register */
#define DMA_DRTOSR 0x10 /* Request timeout Register */
#define DMA_DSESR 0x14 /* Transfer Error Status Register */
#define DMA_DBOSR 0x18 /* Buffer overflow status Register */
#define DMA_DBTOCR 0x1c /* Burst timeout control Register */
#define DMA_WSRA 0x40 /* W-Size Register A */
#define DMA_XSRA 0x44 /* X-Size Register A */
#define DMA_YSRA 0x48 /* Y-Size Register A */
#define DMA_WSRB 0x4c /* W-Size Register B */
#define DMA_XSRB 0x50 /* X-Size Register B */
#define DMA_YSRB 0x54 /* Y-Size Register B */
#define DMA_SAR(x) (0x80 + ((x) << 6)) /* Source Address Registers */
#define DMA_DAR(x) (0x84 + ((x) << 6)) /* Destination Address Registers */
#define DMA_CNTR(x) (0x88 + ((x) << 6)) /* Count Registers */
#define DMA_CCR(x) (0x8c + ((x) << 6)) /* Control Registers */
#define DMA_RSSR(x) (0x90 + ((x) << 6)) /* Request source select Registers */
#define DMA_BLR(x) (0x94 + ((x) << 6)) /* Burst length Registers */
#define DMA_RTOR(x) (0x98 + ((x) << 6)) /* Request timeout Registers */
#define DMA_BUCR(x) (0x98 + ((x) << 6)) /* Bus Utilization Registers */
#define DMA_CCNR(x) (0x9C + ((x) << 6)) /* Channel counter Registers */
#define DCR_DRST (1<<1)
#define DCR_DEN (1<<0)
#define DBTOCR_EN (1<<15)
#define DBTOCR_CNT(x) ((x) & 0x7fff)
#define CNTR_CNT(x) ((x) & 0xffffff)
#define CCR_ACRPT (1<<14)
#define CCR_DMOD_LINEAR (0x0 << 12)
#define CCR_DMOD_2D (0x1 << 12)
#define CCR_DMOD_FIFO (0x2 << 12)
#define CCR_DMOD_EOBFIFO (0x3 << 12)
#define CCR_SMOD_LINEAR (0x0 << 10)
#define CCR_SMOD_2D (0x1 << 10)
#define CCR_SMOD_FIFO (0x2 << 10)
#define CCR_SMOD_EOBFIFO (0x3 << 10)
#define CCR_MDIR_DEC (1<<9)
#define CCR_MSEL_B (1<<8)
#define CCR_DSIZ_32 (0x0 << 6)
#define CCR_DSIZ_8 (0x1 << 6)
#define CCR_DSIZ_16 (0x2 << 6)
#define CCR_SSIZ_32 (0x0 << 4)
#define CCR_SSIZ_8 (0x1 << 4)
#define CCR_SSIZ_16 (0x2 << 4)
#define CCR_REN (1<<3)
#define CCR_RPT (1<<2)
#define CCR_FRC (1<<1)
#define CCR_CEN (1<<0)
#define RTOR_EN (1<<15)
#define RTOR_CLK (1<<14)
#define RTOR_PSC (1<<13)
/*
* struct imx_dma_channel - i.MX specific DMA extension
* @name: name specified by DMA client
* @irq_handler: client callback for end of transfer
* @err_handler: client callback for error condition
* @data: clients context data for callbacks
* @dma_mode: direction of the transfer %DMA_MODE_READ or %DMA_MODE_WRITE
* @sg: pointer to the actual read/written chunk for scatter-gather emulation
* @resbytes: total residual number of bytes to transfer
* (it can be lower or same as sum of SG mapped chunk sizes)
* @sgcount: number of chunks to be read/written
*
* Structure is used for IMX DMA processing. It would be probably good
* @struct dma_struct in the future for external interfacing and use
* @struct imx_dma_channel only as extension to it.
*/
struct imx_dma_channel {
const char *name;
void (*irq_handler) (int, void *);
void (*err_handler) (int, void *, int errcode);
void (*prog_handler) (int, void *, struct scatterlist *);
void *data;
unsigned int dma_mode;
struct scatterlist *sg;
unsigned int resbytes;
int dma_num;
int in_use;
u32 ccr_from_device;
u32 ccr_to_device;
struct timer_list watchdog;
int hw_chaining;
};
static struct imx_dma_channel imx_dma_channels[IMX_DMA_CHANNELS];
static struct clk *dma_clk;
static int imx_dma_hw_chain(struct imx_dma_channel *imxdma)
{
if (cpu_is_mx27())
return imxdma->hw_chaining;
else
return 0;
}
/*
* imx_dma_sg_next - prepare next chunk for scatter-gather DMA emulation
*/
static inline int imx_dma_sg_next(int channel, struct scatterlist *sg)
{
struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
unsigned long now;
if (!imxdma->name) {
printk(KERN_CRIT "%s: called for not allocated channel %d\n",
__func__, channel);
return 0;
}
now = min(imxdma->resbytes, sg->length);
if (imxdma->resbytes != IMX_DMA_LENGTH_LOOP)
imxdma->resbytes -= now;
if ((imxdma->dma_mode & DMA_MODE_MASK) == DMA_MODE_READ)
__raw_writel(sg->dma_address, DMA_BASE + DMA_DAR(channel));
else
__raw_writel(sg->dma_address, DMA_BASE + DMA_SAR(channel));
__raw_writel(now, DMA_BASE + DMA_CNTR(channel));
pr_debug("imxdma%d: next sg chunk dst 0x%08x, src 0x%08x, "
"size 0x%08x\n", channel,
__raw_readl(DMA_BASE + DMA_DAR(channel)),
__raw_readl(DMA_BASE + DMA_SAR(channel)),
__raw_readl(DMA_BASE + DMA_CNTR(channel)));
return now;
}
/**
* imx_dma_setup_single - setup i.MX DMA channel for linear memory to/from
* device transfer
*
* @channel: i.MX DMA channel number
* @dma_address: the DMA/physical memory address of the linear data block
* to transfer
* @dma_length: length of the data block in bytes
* @dev_addr: physical device port address
* @dmamode: DMA transfer mode, %DMA_MODE_READ from the device to the memory
* or %DMA_MODE_WRITE from memory to the device
*
* Return value: if incorrect parameters are provided -%EINVAL.
* Zero indicates success.
*/
int
imx_dma_setup_single(int channel, dma_addr_t dma_address,
unsigned int dma_length, unsigned int dev_addr,
unsigned int dmamode)
{
struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
imxdma->sg = NULL;
imxdma->dma_mode = dmamode;
if (!dma_address) {
printk(KERN_ERR "imxdma%d: imx_dma_setup_single null address\n",
channel);
return -EINVAL;
}
if (!dma_length) {
printk(KERN_ERR "imxdma%d: imx_dma_setup_single zero length\n",
channel);
return -EINVAL;
}
if ((dmamode & DMA_MODE_MASK) == DMA_MODE_READ) {
pr_debug("imxdma%d: %s dma_addressg=0x%08x dma_length=%d "
"dev_addr=0x%08x for read\n",
channel, __func__, (unsigned int)dma_address,
dma_length, dev_addr);
__raw_writel(dev_addr, DMA_BASE + DMA_SAR(channel));
__raw_writel(dma_address, DMA_BASE + DMA_DAR(channel));
__raw_writel(imxdma->ccr_from_device,
DMA_BASE + DMA_CCR(channel));
} else if ((dmamode & DMA_MODE_MASK) == DMA_MODE_WRITE) {
pr_debug("imxdma%d: %s dma_addressg=0x%08x dma_length=%d "
"dev_addr=0x%08x for write\n",
channel, __func__, (unsigned int)dma_address,
dma_length, dev_addr);
__raw_writel(dma_address, DMA_BASE + DMA_SAR(channel));
__raw_writel(dev_addr, DMA_BASE + DMA_DAR(channel));
__raw_writel(imxdma->ccr_to_device,
DMA_BASE + DMA_CCR(channel));
} else {
printk(KERN_ERR "imxdma%d: imx_dma_setup_single bad dmamode\n",
channel);
return -EINVAL;
}
__raw_writel(dma_length, DMA_BASE + DMA_CNTR(channel));
return 0;
}
EXPORT_SYMBOL(imx_dma_setup_single);
/**
* imx_dma_setup_sg - setup i.MX DMA channel SG list to/from device transfer
* @channel: i.MX DMA channel number
* @sg: pointer to the scatter-gather list/vector
* @sgcount: scatter-gather list hungs count
* @dma_length: total length of the transfer request in bytes
* @dev_addr: physical device port address
* @dmamode: DMA transfer mode, %DMA_MODE_READ from the device to the memory
* or %DMA_MODE_WRITE from memory to the device
*
* The function sets up DMA channel state and registers to be ready for
* transfer specified by provided parameters. The scatter-gather emulation
* is set up according to the parameters.
*
* The full preparation of the transfer requires setup of more register
* by the caller before imx_dma_enable() can be called.
*
* %BLR(channel) holds transfer burst length in bytes, 0 means 64 bytes
*
* %RSSR(channel) has to be set to the DMA request line source %DMA_REQ_xxx
*
* %CCR(channel) has to specify transfer parameters, the next settings is
* typical for linear or simple scatter-gather transfers if %DMA_MODE_READ is
* specified
*
* %CCR_DMOD_LINEAR | %CCR_DSIZ_32 | %CCR_SMOD_FIFO | %CCR_SSIZ_x
*
* The typical setup for %DMA_MODE_WRITE is specified by next options
* combination
*
* %CCR_SMOD_LINEAR | %CCR_SSIZ_32 | %CCR_DMOD_FIFO | %CCR_DSIZ_x
*
* Be careful here and do not mistakenly mix source and target device
* port sizes constants, they are really different:
* %CCR_SSIZ_8, %CCR_SSIZ_16, %CCR_SSIZ_32,
* %CCR_DSIZ_8, %CCR_DSIZ_16, %CCR_DSIZ_32
*
* Return value: if incorrect parameters are provided -%EINVAL.
* Zero indicates success.
*/
int
imx_dma_setup_sg(int channel,
struct scatterlist *sg, unsigned int sgcount,
unsigned int dma_length, unsigned int dev_addr,
unsigned int dmamode)
{
struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
if (imxdma->in_use)
return -EBUSY;
imxdma->sg = sg;
imxdma->dma_mode = dmamode;
imxdma->resbytes = dma_length;
if (!sg || !sgcount) {
printk(KERN_ERR "imxdma%d: imx_dma_setup_sg epty sg list\n",
channel);
return -EINVAL;
}
if (!sg->length) {
printk(KERN_ERR "imxdma%d: imx_dma_setup_sg zero length\n",
channel);
return -EINVAL;
}
if ((dmamode & DMA_MODE_MASK) == DMA_MODE_READ) {
pr_debug("imxdma%d: %s sg=%p sgcount=%d total length=%d "
"dev_addr=0x%08x for read\n",
channel, __func__, sg, sgcount, dma_length, dev_addr);
__raw_writel(dev_addr, DMA_BASE + DMA_SAR(channel));
__raw_writel(imxdma->ccr_from_device,
DMA_BASE + DMA_CCR(channel));
} else if ((dmamode & DMA_MODE_MASK) == DMA_MODE_WRITE) {
pr_debug("imxdma%d: %s sg=%p sgcount=%d total length=%d "
"dev_addr=0x%08x for write\n",
channel, __func__, sg, sgcount, dma_length, dev_addr);
__raw_writel(dev_addr, DMA_BASE + DMA_DAR(channel));
__raw_writel(imxdma->ccr_to_device,
DMA_BASE + DMA_CCR(channel));
} else {
printk(KERN_ERR "imxdma%d: imx_dma_setup_sg bad dmamode\n",
channel);
return -EINVAL;
}
imx_dma_sg_next(channel, sg);
return 0;
}
EXPORT_SYMBOL(imx_dma_setup_sg);
int
imx_dma_config_channel(int channel, unsigned int config_port,
unsigned int config_mem, unsigned int dmareq, int hw_chaining)
{
struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
u32 dreq = 0;
imxdma->hw_chaining = 0;
if (hw_chaining) {
imxdma->hw_chaining = 1;
if (!imx_dma_hw_chain(imxdma))
return -EINVAL;
}
if (dmareq)
dreq = CCR_REN;
imxdma->ccr_from_device = config_port | (config_mem << 2) | dreq;
imxdma->ccr_to_device = config_mem | (config_port << 2) | dreq;
__raw_writel(dmareq, DMA_BASE + DMA_RSSR(channel));
return 0;
}
EXPORT_SYMBOL(imx_dma_config_channel);
void imx_dma_config_burstlen(int channel, unsigned int burstlen)
{
__raw_writel(burstlen, DMA_BASE + DMA_BLR(channel));
}
EXPORT_SYMBOL(imx_dma_config_burstlen);
/**
* imx_dma_setup_handlers - setup i.MX DMA channel end and error notification
* handlers
* @channel: i.MX DMA channel number
* @irq_handler: the pointer to the function called if the transfer
* ends successfully
* @err_handler: the pointer to the function called if the premature
* end caused by error occurs
* @data: user specified value to be passed to the handlers
*/
int
imx_dma_setup_handlers(int channel,
void (*irq_handler) (int, void *),
void (*err_handler) (int, void *, int),
void *data)
{
struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
unsigned long flags;
if (!imxdma->name) {
printk(KERN_CRIT "%s: called for not allocated channel %d\n",
__func__, channel);
return -ENODEV;
}
local_irq_save(flags);
__raw_writel(1 << channel, DMA_BASE + DMA_DISR);
imxdma->irq_handler = irq_handler;
imxdma->err_handler = err_handler;
imxdma->data = data;
local_irq_restore(flags);
return 0;
}
EXPORT_SYMBOL(imx_dma_setup_handlers);
/**
* imx_dma_setup_progression_handler - setup i.MX DMA channel progression
* handlers
* @channel: i.MX DMA channel number
* @prog_handler: the pointer to the function called if the transfer progresses
*/
int
imx_dma_setup_progression_handler(int channel,
void (*prog_handler) (int, void*, struct scatterlist*))
{
struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
unsigned long flags;
if (!imxdma->name) {
printk(KERN_CRIT "%s: called for not allocated channel %d\n",
__func__, channel);
return -ENODEV;
}
local_irq_save(flags);
imxdma->prog_handler = prog_handler;
local_irq_restore(flags);
return 0;
}
EXPORT_SYMBOL(imx_dma_setup_progression_handler);
/**
* imx_dma_enable - function to start i.MX DMA channel operation
* @channel: i.MX DMA channel number
*
* The channel has to be allocated by driver through imx_dma_request()
* or imx_dma_request_by_prio() function.
* The transfer parameters has to be set to the channel registers through
* call of the imx_dma_setup_single() or imx_dma_setup_sg() function
* and registers %BLR(channel), %RSSR(channel) and %CCR(channel) has to
* be set prior this function call by the channel user.
*/
void imx_dma_enable(int channel)
{
struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
unsigned long flags;
pr_debug("imxdma%d: imx_dma_enable\n", channel);
if (!imxdma->name) {
printk(KERN_CRIT "%s: called for not allocated channel %d\n",
__func__, channel);
return;
}
if (imxdma->in_use)
return;
local_irq_save(flags);
__raw_writel(1 << channel, DMA_BASE + DMA_DISR);
__raw_writel(__raw_readl(DMA_BASE + DMA_DIMR) & ~(1 << channel),
DMA_BASE + DMA_DIMR);
__raw_writel(__raw_readl(DMA_BASE + DMA_CCR(channel)) | CCR_CEN |
CCR_ACRPT,
DMA_BASE + DMA_CCR(channel));
#ifdef CONFIG_ARCH_MX2
if (imxdma->sg && imx_dma_hw_chain(imxdma)) {
imxdma->sg = sg_next(imxdma->sg);
if (imxdma->sg) {
u32 tmp;
imx_dma_sg_next(channel, imxdma->sg);
tmp = __raw_readl(DMA_BASE + DMA_CCR(channel));
__raw_writel(tmp | CCR_RPT | CCR_ACRPT,
DMA_BASE + DMA_CCR(channel));
}
}
#endif
imxdma->in_use = 1;
local_irq_restore(flags);
}
EXPORT_SYMBOL(imx_dma_enable);
/**
* imx_dma_disable - stop, finish i.MX DMA channel operatin
* @channel: i.MX DMA channel number
*/
void imx_dma_disable(int channel)
{
struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
unsigned long flags;
pr_debug("imxdma%d: imx_dma_disable\n", channel);
if (imx_dma_hw_chain(imxdma))
del_timer(&imxdma->watchdog);
local_irq_save(flags);
__raw_writel(__raw_readl(DMA_BASE + DMA_DIMR) | (1 << channel),
DMA_BASE + DMA_DIMR);
__raw_writel(__raw_readl(DMA_BASE + DMA_CCR(channel)) & ~CCR_CEN,
DMA_BASE + DMA_CCR(channel));
__raw_writel(1 << channel, DMA_BASE + DMA_DISR);
imxdma->in_use = 0;
local_irq_restore(flags);
}
EXPORT_SYMBOL(imx_dma_disable);
#ifdef CONFIG_ARCH_MX2
static void imx_dma_watchdog(unsigned long chno)
{
struct imx_dma_channel *imxdma = &imx_dma_channels[chno];
__raw_writel(0, DMA_BASE + DMA_CCR(chno));
imxdma->in_use = 0;
imxdma->sg = NULL;
if (imxdma->err_handler)
imxdma->err_handler(chno, imxdma->data, IMX_DMA_ERR_TIMEOUT);
}
#endif
static irqreturn_t dma_err_handler(int irq, void *dev_id)
{
int i, disr;
struct imx_dma_channel *imxdma;
unsigned int err_mask;
int errcode;
disr = __raw_readl(DMA_BASE + DMA_DISR);
err_mask = __raw_readl(DMA_BASE + DMA_DBTOSR) |
__raw_readl(DMA_BASE + DMA_DRTOSR) |
__raw_readl(DMA_BASE + DMA_DSESR) |
__raw_readl(DMA_BASE + DMA_DBOSR);
if (!err_mask)
return IRQ_HANDLED;
__raw_writel(disr & err_mask, DMA_BASE + DMA_DISR);
for (i = 0; i < IMX_DMA_CHANNELS; i++) {
if (!(err_mask & (1 << i)))
continue;
imxdma = &imx_dma_channels[i];
errcode = 0;
if (__raw_readl(DMA_BASE + DMA_DBTOSR) & (1 << i)) {
__raw_writel(1 << i, DMA_BASE + DMA_DBTOSR);
errcode |= IMX_DMA_ERR_BURST;
}
if (__raw_readl(DMA_BASE + DMA_DRTOSR) & (1 << i)) {
__raw_writel(1 << i, DMA_BASE + DMA_DRTOSR);
errcode |= IMX_DMA_ERR_REQUEST;
}
if (__raw_readl(DMA_BASE + DMA_DSESR) & (1 << i)) {
__raw_writel(1 << i, DMA_BASE + DMA_DSESR);
errcode |= IMX_DMA_ERR_TRANSFER;
}
if (__raw_readl(DMA_BASE + DMA_DBOSR) & (1 << i)) {
__raw_writel(1 << i, DMA_BASE + DMA_DBOSR);
errcode |= IMX_DMA_ERR_BUFFER;
}
if (imxdma->name && imxdma->err_handler) {
imxdma->err_handler(i, imxdma->data, errcode);
continue;
}
imx_dma_channels[i].sg = NULL;
printk(KERN_WARNING
"DMA timeout on channel %d (%s) -%s%s%s%s\n",
i, imxdma->name,
errcode & IMX_DMA_ERR_BURST ? " burst" : "",
errcode & IMX_DMA_ERR_REQUEST ? " request" : "",
errcode & IMX_DMA_ERR_TRANSFER ? " transfer" : "",
errcode & IMX_DMA_ERR_BUFFER ? " buffer" : "");
}
return IRQ_HANDLED;
}
static void dma_irq_handle_channel(int chno)
{
struct imx_dma_channel *imxdma = &imx_dma_channels[chno];
if (!imxdma->name) {
/*
* IRQ for an unregistered DMA channel:
* let's clear the interrupts and disable it.
*/
printk(KERN_WARNING
"spurious IRQ for DMA channel %d\n", chno);
return;
}
if (imxdma->sg) {
u32 tmp;
struct scatterlist *current_sg = imxdma->sg;
imxdma->sg = sg_next(imxdma->sg);
if (imxdma->sg) {
imx_dma_sg_next(chno, imxdma->sg);
tmp = __raw_readl(DMA_BASE + DMA_CCR(chno));
if (imx_dma_hw_chain(imxdma)) {
/* FIXME: The timeout should probably be
* configurable
*/
mod_timer(&imxdma->watchdog,
jiffies + msecs_to_jiffies(500));
tmp |= CCR_CEN | CCR_RPT | CCR_ACRPT;
__raw_writel(tmp, DMA_BASE +
DMA_CCR(chno));
} else {
__raw_writel(tmp & ~CCR_CEN, DMA_BASE +
DMA_CCR(chno));
tmp |= CCR_CEN;
}
__raw_writel(tmp, DMA_BASE + DMA_CCR(chno));
if (imxdma->prog_handler)
imxdma->prog_handler(chno, imxdma->data,
current_sg);
return;
}
if (imx_dma_hw_chain(imxdma)) {
del_timer(&imxdma->watchdog);
return;
}
}
__raw_writel(0, DMA_BASE + DMA_CCR(chno));
imxdma->in_use = 0;
if (imxdma->irq_handler)
imxdma->irq_handler(chno, imxdma->data);
}
static irqreturn_t dma_irq_handler(int irq, void *dev_id)
{
int i, disr;
#ifdef CONFIG_ARCH_MX2
dma_err_handler(irq, dev_id);
#endif
disr = __raw_readl(DMA_BASE + DMA_DISR);
pr_debug("imxdma: dma_irq_handler called, disr=0x%08x\n",
disr);
__raw_writel(disr, DMA_BASE + DMA_DISR);
for (i = 0; i < IMX_DMA_CHANNELS; i++) {
if (disr & (1 << i))
dma_irq_handle_channel(i);
}
return IRQ_HANDLED;
}
/**
* imx_dma_request - request/allocate specified channel number
* @channel: i.MX DMA channel number
* @name: the driver/caller own non-%NULL identification
*/
int imx_dma_request(int channel, const char *name)
{
struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
unsigned long flags;
int ret = 0;
/* basic sanity checks */
if (!name)
return -EINVAL;
if (channel >= IMX_DMA_CHANNELS) {
printk(KERN_CRIT "%s: called for non-existed channel %d\n",
__func__, channel);
return -EINVAL;
}
local_irq_save(flags);
if (imxdma->name) {
local_irq_restore(flags);
return -EBUSY;
}
memset(imxdma, 0, sizeof(imxdma));
imxdma->name = name;
local_irq_restore(flags); /* request_irq() can block */
#ifdef CONFIG_ARCH_MX2
ret = request_irq(MXC_INT_DMACH0 + channel, dma_irq_handler, 0, "DMA",
NULL);
if (ret) {
imxdma->name = NULL;
printk(KERN_CRIT "Can't register IRQ %d for DMA channel %d\n",
MXC_INT_DMACH0 + channel, channel);
return ret;
}
init_timer(&imxdma->watchdog);
imxdma->watchdog.function = &imx_dma_watchdog;
imxdma->watchdog.data = channel;
#endif
return ret;
}
EXPORT_SYMBOL(imx_dma_request);
/**
* imx_dma_free - release previously acquired channel
* @channel: i.MX DMA channel number
*/
void imx_dma_free(int channel)
{
unsigned long flags;
struct imx_dma_channel *imxdma = &imx_dma_channels[channel];
if (!imxdma->name) {
printk(KERN_CRIT
"%s: trying to free free channel %d\n",
__func__, channel);
return;
}
local_irq_save(flags);
/* Disable interrupts */
imx_dma_disable(channel);
imxdma->name = NULL;
#ifdef CONFIG_ARCH_MX2
free_irq(MXC_INT_DMACH0 + channel, NULL);
#endif
local_irq_restore(flags);
}
EXPORT_SYMBOL(imx_dma_free);
/**
* imx_dma_request_by_prio - find and request some of free channels best
* suiting requested priority
* @channel: i.MX DMA channel number
* @name: the driver/caller own non-%NULL identification
*
* This function tries to find a free channel in the specified priority group
* This function tries to find a free channel in the specified priority group
* if the priority cannot be achieved it tries to look for free channel
* in the higher and then even lower priority groups.
*
* Return value: If there is no free channel to allocate, -%ENODEV is returned.
* On successful allocation channel is returned.
*/
int imx_dma_request_by_prio(const char *name, enum imx_dma_prio prio)
{
int i;
int best;
switch (prio) {
case (DMA_PRIO_HIGH):
best = 8;
break;
case (DMA_PRIO_MEDIUM):
best = 4;
break;
case (DMA_PRIO_LOW):
default:
best = 0;
break;
}
for (i = best; i < IMX_DMA_CHANNELS; i++)
if (!imx_dma_request(i, name))
return i;
for (i = best - 1; i >= 0; i--)
if (!imx_dma_request(i, name))
return i;
printk(KERN_ERR "%s: no free DMA channel found\n", __func__);
return -ENODEV;
}
EXPORT_SYMBOL(imx_dma_request_by_prio);
static int __init imx_dma_init(void)
{
int ret = 0;
int i;
dma_clk = clk_get(NULL, "dma");
clk_enable(dma_clk);
/* reset DMA module */
__raw_writel(DCR_DRST, DMA_BASE + DMA_DCR);
#ifdef CONFIG_ARCH_MX1
ret = request_irq(DMA_INT, dma_irq_handler, 0, "DMA", NULL);
if (ret) {
printk(KERN_CRIT "Wow! Can't register IRQ for DMA\n");
return ret;
}
ret = request_irq(DMA_ERR, dma_err_handler, 0, "DMA", NULL);
if (ret) {
printk(KERN_CRIT "Wow! Can't register ERRIRQ for DMA\n");
free_irq(DMA_INT, NULL);
return ret;
}
#endif
/* enable DMA module */
__raw_writel(DCR_DEN, DMA_BASE + DMA_DCR);
/* clear all interrupts */
__raw_writel((1 << IMX_DMA_CHANNELS) - 1, DMA_BASE + DMA_DISR);
/* disable interrupts */
__raw_writel((1 << IMX_DMA_CHANNELS) - 1, DMA_BASE + DMA_DIMR);
for (i = 0; i < IMX_DMA_CHANNELS; i++) {
imx_dma_channels[i].sg = NULL;
imx_dma_channels[i].dma_num = i;
}
return ret;
}
arch_initcall(imx_dma_init);