--- /dev/null
+/*
+ * 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 <asm/dma.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;
+ dmamode_t 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);
+ 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,
+ dmamode_t 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,
+ dmamode_t 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);
+
+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);
+}
+
+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;
+
+ /* 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;
+ }
+
+#ifdef CONFIG_ARCH_MX2
+ ret = request_irq(MXC_INT_DMACH0 + channel, dma_irq_handler, 0, "DMA",
+ NULL);
+ if (ret) {
+ 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
+
+ imxdma->name = name;
+ imxdma->irq_handler = NULL;
+ imxdma->err_handler = NULL;
+ imxdma->data = NULL;
+ imxdma->sg = NULL;
+
+ local_irq_restore(flags);
+ return 0;
+}
+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 */
+ __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));
+ 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");
+ 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);
projects / openwrt / staging / blogic.git / commitdiff