+ 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;
+
+ if (!imxdma->name) {
+ printk(KERN_CRIT "%s: called for not allocated channel %d\n",
+ __FUNCTION__, 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",
+ __FUNCTION__, 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",
+ __FUNCTION__, 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;