* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
- * 2004-03-03 Sascha Hauer <sascha@saschahauer.de>
+ * 03/03/2004 Sascha Hauer <sascha@saschahauer.de>
* initial version heavily inspired by
* linux/arch/arm/mach-pxa/dma.c
- *
- * 2005-04-17 Pavel Pisa <pisa@cmp.felk.cvut.cz>
- * Changed to support scatter gather DMA
- * by taking Russell's code from RiscPC
- *
- * 2006-05-31 Pavel Pisa <pisa@cmp.felk.cvut.cz>
- * Corrected error handling code.
- *
*/
-#undef DEBUG
-
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <asm/irq.h>
#include <asm/hardware.h>
#include <asm/dma.h>
-#include <asm/arch/imx-dma.h>
-
-struct imx_dma_channel imx_dma_channels[IMX_DMA_CHANNELS];
-
-/*
- * imx_dma_sg_next - prepare next chunk for scatter-gather DMA emulation
- * @dma_ch: i.MX DMA channel number
- * @lastcount: number of bytes transferred during last transfer
- *
- * Functions prepares DMA controller for next sg data chunk transfer.
- * The @lastcount argument informs function about number of bytes transferred
- * during last block. Zero value can be used for @lastcount to setup DMA
- * for the first chunk.
- */
-static inline int imx_dma_sg_next(imx_dmach_t dma_ch, unsigned int lastcount)
-{
- struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch];
- unsigned int nextcount;
- unsigned int nextaddr;
-
- if (!imxdma->name) {
- printk(KERN_CRIT "%s: called for not allocated channel %d\n",
- __FUNCTION__, dma_ch);
- return 0;
- }
-
- imxdma->resbytes -= lastcount;
-
- if (!imxdma->sg) {
- pr_debug("imxdma%d: no sg data\n", dma_ch);
- return 0;
- }
-
- imxdma->sgbc += lastcount;
- if ((imxdma->sgbc >= imxdma->sg->length) || !imxdma->resbytes) {
- if ((imxdma->sgcount <= 1) || !imxdma->resbytes) {
- pr_debug("imxdma%d: sg transfer limit reached\n",
- dma_ch);
- imxdma->sgcount=0;
- imxdma->sg = NULL;
- return 0;
- } else {
- imxdma->sgcount--;
- imxdma->sg++;
- imxdma->sgbc = 0;
- }
- }
- nextcount = imxdma->sg->length - imxdma->sgbc;
- nextaddr = imxdma->sg->dma_address + imxdma->sgbc;
-
- if(imxdma->resbytes < nextcount)
- nextcount = imxdma->resbytes;
- if ((imxdma->dma_mode & DMA_MODE_MASK) == DMA_MODE_READ)
- DAR(dma_ch) = nextaddr;
- else
- SAR(dma_ch) = nextaddr;
+static struct dma_channel {
+ char *name;
+ void (*irq_handler) (int, void *, struct pt_regs *);
+ void (*err_handler) (int, void *, struct pt_regs *);
+ void *data;
+} dma_channels[11];
- CNTR(dma_ch) = nextcount;
- pr_debug("imxdma%d: next sg chunk dst 0x%08x, src 0x%08x, size 0x%08x\n",
- dma_ch, DAR(dma_ch), SAR(dma_ch), CNTR(dma_ch));
-
- return nextcount;
-}
-
-/*
- * imx_dma_setup_sg_base - scatter-gather DMA emulation
- * @dma_ch: i.MX DMA channel number
- * @sg: pointer to the scatter-gather list/vector
- * @sgcount: scatter-gather list hungs count
- *
- * Functions sets up i.MX DMA state for emulated scatter-gather transfer
- * and sets up channel registers to be ready for the first chunk
- */
-static int
-imx_dma_setup_sg_base(imx_dmach_t dma_ch,
- struct scatterlist *sg, unsigned int sgcount)
-{
- struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch];
-
- imxdma->sg = sg;
- imxdma->sgcount = sgcount;
- imxdma->sgbc = 0;
- return imx_dma_sg_next(dma_ch, 0);
-}
-
-/**
- * imx_dma_setup_single - setup i.MX DMA channel for linear memory to/from device transfer
- * @dma_ch: 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
- *
- * The function setups DMA channel source and destination addresses for transfer
- * specified by provided parameters. The scatter-gather emulation is disabled,
- * because linear data block
- * form the physical address range is transfered.
- * Return value: if incorrect parameters are provided -%EINVAL.
- * Zero indicates success.
- */
+/* set err_handler to NULL to have the standard info-only error handler */
int
-imx_dma_setup_single(imx_dmach_t dma_ch, dma_addr_t dma_address,
- unsigned int dma_length, unsigned int dev_addr,
- dmamode_t dmamode)
+imx_request_dma(char *name, imx_dma_prio prio,
+ void (*irq_handler) (int, void *, struct pt_regs *),
+ void (*err_handler) (int, void *, struct pt_regs *), void *data)
{
- struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch];
-
- imxdma->sg = NULL;
- imxdma->sgcount = 0;
- imxdma->dma_mode = dmamode;
- imxdma->resbytes = dma_length;
-
- if (!dma_address) {
- printk(KERN_ERR "imxdma%d: imx_dma_setup_single null address\n",
- dma_ch);
- return -EINVAL;
- }
-
- if (!dma_length) {
- printk(KERN_ERR "imxdma%d: imx_dma_setup_single zero length\n",
- dma_ch);
- return -EINVAL;
- }
-
- if ((dmamode & DMA_MODE_MASK) == DMA_MODE_READ) {
- pr_debug("imxdma%d: mx_dma_setup_single2dev dma_addressg=0x%08x dma_length=%d dev_addr=0x%08x for read\n",
- dma_ch, (unsigned int)dma_address, dma_length,
- dev_addr);
- SAR(dma_ch) = dev_addr;
- DAR(dma_ch) = (unsigned int)dma_address;
- } else if ((dmamode & DMA_MODE_MASK) == DMA_MODE_WRITE) {
- pr_debug("imxdma%d: mx_dma_setup_single2dev dma_addressg=0x%08x dma_length=%d dev_addr=0x%08x for write\n",
- dma_ch, (unsigned int)dma_address, dma_length,
- dev_addr);
- SAR(dma_ch) = (unsigned int)dma_address;
- DAR(dma_ch) = dev_addr;
- } else {
- printk(KERN_ERR "imxdma%d: imx_dma_setup_single bad dmamode\n",
- dma_ch);
- return -EINVAL;
- }
-
- CNTR(dma_ch) = dma_length;
-
- return 0;
-}
-
-/**
- * imx_dma_setup_sg - setup i.MX DMA channel SG list to/from device transfer
- * @dma_ch: 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 setups 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(dma_ch) holds transfer burst length in bytes, 0 means 64 bytes
- *
- * %RSSR(dma_ch) has to be set to the DMA request line source %DMA_REQ_xxx
- *
- * %CCR(dma_ch) 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 carefull there 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(imx_dmach_t dma_ch,
- struct scatterlist *sg, unsigned int sgcount, unsigned int dma_length,
- unsigned int dev_addr, dmamode_t dmamode)
-{
- int res;
- struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch];
-
- imxdma->sg = NULL;
- imxdma->sgcount = 0;
- imxdma->dma_mode = dmamode;
- imxdma->resbytes = dma_length;
-
- if (!sg || !sgcount) {
- printk(KERN_ERR "imxdma%d: imx_dma_setup_sg epty sg list\n",
- dma_ch);
- return -EINVAL;
- }
-
- if (!sg->length) {
- printk(KERN_ERR "imxdma%d: imx_dma_setup_sg zero length\n",
- dma_ch);
- return -EINVAL;
- }
-
- if ((dmamode & DMA_MODE_MASK) == DMA_MODE_READ) {
- pr_debug("imxdma%d: mx_dma_setup_sg2dev sg=%p sgcount=%d total length=%d dev_addr=0x%08x for read\n",
- dma_ch, sg, sgcount, dma_length, dev_addr);
- SAR(dma_ch) = dev_addr;
- } else if ((dmamode & DMA_MODE_MASK) == DMA_MODE_WRITE) {
- pr_debug("imxdma%d: mx_dma_setup_sg2dev sg=%p sgcount=%d total length=%d dev_addr=0x%08x for write\n",
- dma_ch, sg, sgcount, dma_length, dev_addr);
- DAR(dma_ch) = dev_addr;
- } else {
- printk(KERN_ERR "imxdma%d: imx_dma_setup_sg bad dmamode\n",
- dma_ch);
- return -EINVAL;
- }
-
- res = imx_dma_setup_sg_base(dma_ch, sg, sgcount);
- if (res <= 0) {
- printk(KERN_ERR "imxdma%d: no sg chunk ready\n", dma_ch);
- return -EINVAL;
- }
-
- return 0;
-}
-
-/**
- * imx_dma_setup_handlers - setup i.MX DMA channel end and error notification handlers
- * @dma_ch: 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(imx_dmach_t dma_ch,
- void (*irq_handler) (int, void *, struct pt_regs *),
- void (*err_handler) (int, void *, struct pt_regs *, int),
- void *data)
-{
- struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch];
unsigned long flags;
+ int i, found = 0;
- if (!imxdma->name) {
- printk(KERN_CRIT "%s: called for not allocated channel %d\n",
- __FUNCTION__, dma_ch);
- return -ENODEV;
- }
+ /* basic sanity checks */
+ if (!name || !irq_handler)
+ return -EINVAL;
local_irq_save(flags);
- DISR = (1 << dma_ch);
- imxdma->irq_handler = irq_handler;
- imxdma->err_handler = err_handler;
- imxdma->data = data;
- local_irq_restore(flags);
- return 0;
-}
-/**
- * imx_dma_enable - function to start i.MX DMA channel operation
- * @dma_ch: 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(dma_ch), %RSSR(dma_ch) and %CCR(dma_ch) has to
- * be set prior this function call by the channel user.
- */
-void imx_dma_enable(imx_dmach_t dma_ch)
-{
- struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch];
- unsigned long flags;
-
- pr_debug("imxdma%d: imx_dma_enable\n", dma_ch);
-
- if (!imxdma->name) {
- printk(KERN_CRIT "%s: called for not allocated channel %d\n",
- __FUNCTION__, dma_ch);
- return;
+ /* try grabbing a DMA channel with the requested priority */
+ for (i = prio; i < prio + (prio == DMA_PRIO_LOW) ? 8 : 4; i++) {
+ if (!dma_channels[i].name) {
+ found = 1;
+ break;
+ }
}
- local_irq_save(flags);
- DISR = (1 << dma_ch);
- DIMR &= ~(1 << dma_ch);
- CCR(dma_ch) |= CCR_CEN;
- local_irq_restore(flags);
-}
-
-/**
- * imx_dma_disable - stop, finish i.MX DMA channel operatin
- * @dma_ch: i.MX DMA channel number
- */
-void imx_dma_disable(imx_dmach_t dma_ch)
-{
- unsigned long flags;
-
- pr_debug("imxdma%d: imx_dma_disable\n", dma_ch);
-
- local_irq_save(flags);
- DIMR |= (1 << dma_ch);
- CCR(dma_ch) &= ~CCR_CEN;
- DISR = (1 << dma_ch);
- local_irq_restore(flags);
-}
-
-/**
- * imx_dma_request - request/allocate specified channel number
- * @dma_ch: i.MX DMA channel number
- * @name: the driver/caller own non-%NULL identification
- */
-int imx_dma_request(imx_dmach_t dma_ch, const char *name)
-{
- struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch];
- unsigned long flags;
-
- /* basic sanity checks */
- if (!name)
- return -EINVAL;
-
- if (dma_ch >= IMX_DMA_CHANNELS) {
- printk(KERN_CRIT "%s: called for non-existed channel %d\n",
- __FUNCTION__, dma_ch);
- return -EINVAL;
+ if (!found) {
+ /* requested prio group is full, try hier priorities */
+ for (i = prio - 1; i >= 0; i--) {
+ if (!dma_channels[i].name) {
+ found = 1;
+ break;
+ }
+ }
}
- local_irq_save(flags);
- if (imxdma->name) {
- local_irq_restore(flags);
- return -ENODEV;
+ if (found) {
+ DIMR &= ~(1 << i);
+ dma_channels[i].name = name;
+ dma_channels[i].irq_handler = irq_handler;
+ dma_channels[i].err_handler = err_handler;
+ dma_channels[i].data = data;
+ } else {
+ printk(KERN_WARNING "No more available DMA channels for %s\n",
+ name);
+ i = -ENODEV;
}
- imxdma->name = name;
- imxdma->irq_handler = NULL;
- imxdma->err_handler = NULL;
- imxdma->data = NULL;
- imxdma->sg = NULL;
local_irq_restore(flags);
- return 0;
+ return i;
}
-/**
- * imx_dma_free - release previously acquired channel
- * @dma_ch: i.MX DMA channel number
- */
-void imx_dma_free(imx_dmach_t dma_ch)
+void
+imx_free_dma(int dma_ch)
{
unsigned long flags;
- struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch];
- if (!imxdma->name) {
+ if (!dma_channels[dma_ch].name) {
printk(KERN_CRIT
"%s: trying to free channel %d which is already freed\n",
__FUNCTION__, dma_ch);
}
local_irq_save(flags);
- /* Disable interrupts */
- DIMR |= (1 << dma_ch);
- CCR(dma_ch) &= ~CCR_CEN;
- imxdma->name = NULL;
+ DIMR &= ~(1 << dma_ch);
+ dma_channels[dma_ch].name = NULL;
local_irq_restore(flags);
}
-/**
- * imx_dma_request_by_prio - find and request some of free channels best suiting requested priority
- * @dma_ch: i.MX DMA channel number
- * @name: the driver/caller own non-%NULL identification
- * @prio: one of the hardware distinguished priority level:
- * %DMA_PRIO_HIGH, %DMA_PRIO_MEDIUM, %DMA_PRIO_LOW
- *
- * This function tries to find 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.
- * Zero value indicates successful channel allocation.
- */
-int
-imx_dma_request_by_prio(imx_dmach_t * pdma_ch, const char *name,
- 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)) {
- *pdma_ch = i;
- return 0;
- }
- }
-
- for (i = best - 1; i >= 0; i--) {
- if (!imx_dma_request(i, name)) {
- *pdma_ch = i;
- return 0;
- }
- }
-
- printk(KERN_ERR "%s: no free DMA channel found\n", __FUNCTION__);
-
- return -ENODEV;
-}
-
-static irqreturn_t dma_err_handler(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t
+dma_err_handler(int irq, void *dev_id, struct pt_regs *regs)
{
int i, disr = DISR;
- struct imx_dma_channel *channel;
+ struct dma_channel *channel;
unsigned int err_mask = DBTOSR | DRTOSR | DSESR | DBOSR;
- int errcode;
- DISR = disr & err_mask;
- for (i = 0; i < IMX_DMA_CHANNELS; i++) {
- if(!(err_mask & (1 << i)))
+ DISR = disr;
+ for (i = 0; i < 11; i++) {
+ channel = &dma_channels[i];
+
+ if ( (err_mask & 1<<i) && channel->name && channel->err_handler) {
+ channel->err_handler(i, channel->data, regs);
continue;
- channel = &imx_dma_channels[i];
- errcode = 0;
+ }
if (DBTOSR & (1 << i)) {
- DBTOSR = (1 << i);
- errcode |= IMX_DMA_ERR_BURST;
+ printk(KERN_WARNING
+ "Burst timeout on channel %d (%s)\n",
+ i, channel->name);
+ DBTOSR |= (1 << i);
}
if (DRTOSR & (1 << i)) {
- DRTOSR = (1 << i);
- errcode |= IMX_DMA_ERR_REQUEST;
+ printk(KERN_WARNING
+ "Request timeout on channel %d (%s)\n",
+ i, channel->name);
+ DRTOSR |= (1 << i);
}
if (DSESR & (1 << i)) {
- DSESR = (1 << i);
- errcode |= IMX_DMA_ERR_TRANSFER;
+ printk(KERN_WARNING
+ "Transfer timeout on channel %d (%s)\n",
+ i, channel->name);
+ DSESR |= (1 << i);
}
if (DBOSR & (1 << i)) {
- DBOSR = (1 << i);
- errcode |= IMX_DMA_ERR_BUFFER;
+ printk(KERN_WARNING
+ "Buffer overflow timeout on channel %d (%s)\n",
+ i, channel->name);
+ DBOSR |= (1 << i);
}
-
- /*
- * The cleaning of @sg field would be questionable
- * there, because its value can help to compute
- * remaining/transfered bytes count in the handler
- */
- /*imx_dma_channels[i].sg = NULL;*/
-
- if (channel->name && channel->err_handler) {
- channel->err_handler(i, channel->data, regs, errcode);
- continue;
- }
-
- imx_dma_channels[i].sg = NULL;
-
- printk(KERN_WARNING
- "DMA timeout on channel %d (%s) -%s%s%s%s\n",
- i, channel->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 irqreturn_t dma_irq_handler(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t
+dma_irq_handler(int irq, void *dev_id, struct pt_regs *regs)
{
int i, disr = DISR;
- pr_debug("imxdma: dma_irq_handler called, disr=0x%08x\n",
- disr);
-
DISR = disr;
- for (i = 0; i < IMX_DMA_CHANNELS; i++) {
+ for (i = 0; i < 11; i++) {
if (disr & (1 << i)) {
- struct imx_dma_channel *channel = &imx_dma_channels[i];
- if (channel->name) {
- if (imx_dma_sg_next(i, CNTR(i))) {
- CCR(i) &= ~CCR_CEN;
- mb();
- CCR(i) |= CCR_CEN;
- } else {
- if (channel->irq_handler)
- channel->irq_handler(i,
- channel->data, regs);
- }
+ struct dma_channel *channel = &dma_channels[i];
+ if (channel->name && channel->irq_handler) {
+ channel->irq_handler(i, channel->data, regs);
} else {
/*
* IRQ for an unregistered DMA channel:
return IRQ_HANDLED;
}
-static int __init imx_dma_init(void)
+static int __init
+imx_dma_init(void)
{
int ret;
- int i;
/* reset DMA module */
DCR = DCR_DRST;
DCR = DCR_DEN;
/* clear all interrupts */
- DISR = (1 << IMX_DMA_CHANNELS) - 1;
+ DISR = 0x3ff;
/* enable interrupts */
- DIMR = (1 << IMX_DMA_CHANNELS) - 1;
-
- for (i = 0; i < IMX_DMA_CHANNELS; i++) {
- imx_dma_channels[i].sg = NULL;
- imx_dma_channels[i].dma_num = i;
- }
+ DIMR = 0;
return ret;
}
arch_initcall(imx_dma_init);
-EXPORT_SYMBOL(imx_dma_setup_single);
-EXPORT_SYMBOL(imx_dma_setup_sg);
-EXPORT_SYMBOL(imx_dma_setup_handlers);
-EXPORT_SYMBOL(imx_dma_enable);
-EXPORT_SYMBOL(imx_dma_disable);
-EXPORT_SYMBOL(imx_dma_request);
-EXPORT_SYMBOL(imx_dma_free);
-EXPORT_SYMBOL(imx_dma_request_by_prio);
-EXPORT_SYMBOL(imx_dma_channels);
+EXPORT_SYMBOL(imx_request_dma);
+EXPORT_SYMBOL(imx_free_dma);
git://git.onelab.eu / linux-2.6.git / blobdiff