diff options
Diffstat (limited to 'arch/arm/mach-imx/dma.c')
| -rw-r--r-- | arch/arm/mach-imx/dma.c | 597 |
1 files changed, 0 insertions, 597 deletions
diff --git a/arch/arm/mach-imx/dma.c b/arch/arm/mach-imx/dma.c deleted file mode 100644 index 1536583eece..00000000000 --- a/arch/arm/mach-imx/dma.c +++ /dev/null @@ -1,597 +0,0 @@ -/* - * linux/arch/arm/mach-imx/dma.c - * - * imx DMA registration and IRQ dispatching - * - * 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. - * - * 2004-03-03 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 <linux/interrupt.h> -#include <linux/errno.h> - -#include <asm/scatterlist.h> -#include <asm/system.h> -#include <asm/irq.h> -#include <mach/hardware.h> -#include <mach/dma.h> -#include <mach/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", - __func__, 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; - - 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 transferred. - * Return value: if incorrect parameters are provided -%EINVAL. - * Zero indicates success. - */ -int -imx_dma_setup_single(imx_dmach_t dma_ch, dma_addr_t dma_address, - unsigned int dma_length, unsigned int dev_addr, - unsigned int dmamode) -{ - 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 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(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 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(imx_dmach_t dma_ch, - struct scatterlist *sg, unsigned int sgcount, unsigned int dma_length, - unsigned int dev_addr, unsigned int 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 *), - void (*err_handler) (int, void *, int), - void *data) -{ - struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch]; - unsigned long flags; - - if (!imxdma->name) { - printk(KERN_CRIT "%s: called for not allocated channel %d\n", - __func__, dma_ch); - return -ENODEV; - } - - 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", - __func__, dma_ch); - return; - } - - 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", - __func__, dma_ch); - return -EINVAL; - } - - local_irq_save(flags); - if (imxdma->name) { - local_irq_restore(flags); - return -ENODEV; - } - - imxdma->name = name; - imxdma->irq_handler = NULL; - imxdma->err_handler = NULL; - imxdma->data = NULL; - imxdma->sg = NULL; - local_irq_restore(flags); - return 0; -} - -/** - * imx_dma_free - release previously acquired channel - * @dma_ch: i.MX DMA channel number - */ -void imx_dma_free(imx_dmach_t dma_ch) -{ - unsigned long flags; - struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch]; - - if (!imxdma->name) { - printk(KERN_CRIT - "%s: trying to free channel %d which is already freed\n", - __func__, dma_ch); - return; - } - - local_irq_save(flags); - /* Disable interrupts */ - DIMR |= (1 << dma_ch); - CCR(dma_ch) &= ~CCR_CEN; - imxdma->name = NULL; - local_irq_restore(flags); -} - -/** - * imx_dma_request_by_prio - find and request some of free channels best suiting requested priority - * @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. - * On successful allocation channel is returned. - */ -imx_dmach_t imx_dma_request_by_prio(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)) { - 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; -} - -static irqreturn_t dma_err_handler(int irq, void *dev_id) -{ - int i, disr = DISR; - struct imx_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))) - continue; - channel = &imx_dma_channels[i]; - errcode = 0; - - if (DBTOSR & (1 << i)) { - DBTOSR = (1 << i); - errcode |= IMX_DMA_ERR_BURST; - } - if (DRTOSR & (1 << i)) { - DRTOSR = (1 << i); - errcode |= IMX_DMA_ERR_REQUEST; - } - if (DSESR & (1 << i)) { - DSESR = (1 << i); - errcode |= IMX_DMA_ERR_TRANSFER; - } - if (DBOSR & (1 << i)) { - DBOSR = (1 << i); - errcode |= IMX_DMA_ERR_BUFFER; - } - - /* - * The cleaning of @sg field would be questionable - * there, because its value can help to compute - * remaining/transferred bytes count in the handler - */ - /*imx_dma_channels[i].sg = NULL;*/ - - if (channel->name && channel->err_handler) { - channel->err_handler(i, channel->data, 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) -{ - 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++) { - 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); - } - } else { - /* - * IRQ for an unregistered DMA channel: - * let's clear the interrupts and disable it. - */ - printk(KERN_WARNING - "spurious IRQ for DMA channel %d\n", i); - } - } - } - return IRQ_HANDLED; -} - -static int __init imx_dma_init(void) -{ - int ret; - int i; - - /* reset DMA module */ - DCR = DCR_DRST; - - 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); - } - - /* enable DMA module */ - DCR = DCR_DEN; - - /* clear all interrupts */ - DISR = (1 << IMX_DMA_CHANNELS) - 1; - - /* 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; - } - - 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); |