dmaengine: dw: add support of iDMA 32-bit hardware

iDMA 32-bit is Intel designed DMA controller that behaves like Synopsys
Designware DMA. This patch adds a support of the new Intel hardware.

Due to iDMA 32-bit has no autoconfiguration the platform code must
provide a platform data to dw_dma_probe().

By default full FIFO (1024 bytes) is assigned to channel 0. Here we
slice FIFO on equal parts between channels for iDMA 32-bit case.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/dw/core.c

@@ -138,16 +138,32 @@ static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
 	dwc->descs_allocated--;
 }
 
-static void dwc_initialize(struct dw_dma_chan *dwc)
+static void dwc_initialize_chan_idma32(struct dw_dma_chan *dwc)
+{
+	u32 cfghi = 0;
+	u32 cfglo = 0;
+
+	/* Set default burst alignment */
+	cfglo |= IDMA32C_CFGL_DST_BURST_ALIGN | IDMA32C_CFGL_SRC_BURST_ALIGN;
+
+	/* Low 4 bits of the request lines */
+	cfghi |= IDMA32C_CFGH_DST_PER(dwc->dws.dst_id & 0xf);
+	cfghi |= IDMA32C_CFGH_SRC_PER(dwc->dws.src_id & 0xf);
+
+	/* Request line extension (2 bits) */
+	cfghi |= IDMA32C_CFGH_DST_PER_EXT(dwc->dws.dst_id >> 4 & 0x3);
+	cfghi |= IDMA32C_CFGH_SRC_PER_EXT(dwc->dws.src_id >> 4 & 0x3);
+
+	channel_writel(dwc, CFG_LO, cfglo);
+	channel_writel(dwc, CFG_HI, cfghi);
+}
+
+static void dwc_initialize_chan_dw(struct dw_dma_chan *dwc)
 {
-	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
 	u32 cfghi = DWC_CFGH_FIFO_MODE;
 	u32 cfglo = DWC_CFGL_CH_PRIOR(dwc->priority);
 	bool hs_polarity = dwc->dws.hs_polarity;
 
-	if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags))
-		return;
-
 	cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
 	cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);
 
@@ -156,6 +172,19 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
 
 	channel_writel(dwc, CFG_LO, cfglo);
 	channel_writel(dwc, CFG_HI, cfghi);
+}
+
+static void dwc_initialize(struct dw_dma_chan *dwc)
+{
+	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
+
+	if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags))
+		return;
+
+	if (dw->pdata->is_idma32)
+		dwc_initialize_chan_idma32(dwc);
+	else
+		dwc_initialize_chan_dw(dwc);
 
 	/* Enable interrupts */
 	channel_set_bit(dw, MASK.XFER, dwc->mask);
@@ -187,8 +216,13 @@ static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
 static u32 bytes2block(struct dw_dma_chan *dwc, size_t bytes,
 			  unsigned int width, size_t *len)
 {
+	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
 	u32 block;
 
+	/* Always in bytes for iDMA 32-bit */
+	if (dw->pdata->is_idma32)
+		width = 0;
+
 	if ((bytes >> width) > dwc->block_size) {
 		block = dwc->block_size;
 		*len = block << width;
@@ -202,6 +236,11 @@ static u32 bytes2block(struct dw_dma_chan *dwc, size_t bytes,
 
 static size_t block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
 {
+	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
+
+	if (dw->pdata->is_idma32)
+		return IDMA32C_CTLH_BLOCK_TS(block);
+
 	return DWC_CTLH_BLOCK_TS(block) << width;
 }
 
@@ -915,14 +954,16 @@ static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
 {
 	struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 	struct dma_slave_config *sc = &dwc->dma_sconfig;
+	struct dw_dma *dw = to_dw_dma(chan->device);
 	/*
 	 * Fix sconfig's burst size according to dw_dmac. We need to convert
 	 * them as:
 	 * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
 	 *
 	 * NOTE: burst size 2 is not supported by DesignWare controller.
+	 *       iDMA 32-bit supports it.
 	 */
-	u32 s = 2;
+	u32 s = dw->pdata->is_idma32 ? 1 : 2;
 
 	/* Check if chan will be configured for slave transfers */
 	if (!is_slave_direction(sconfig->direction))
@@ -937,12 +978,19 @@ static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
 	return 0;
 }
 
-static void dwc_chan_pause(struct dw_dma_chan *dwc)
+static void dwc_chan_pause(struct dw_dma_chan *dwc, bool drain)
 {
+	struct dw_dma *dw = to_dw_dma(dwc->chan.device);
 	unsigned int		count = 20;	/* timeout iterations */
 	u32			cfglo;
 
 	cfglo = channel_readl(dwc, CFG_LO);
+	if (dw->pdata->is_idma32) {
+		if (drain)
+			cfglo |= IDMA32C_CFGL_CH_DRAIN;
+		else
+			cfglo &= ~IDMA32C_CFGL_CH_DRAIN;
+	}
 	channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
 	while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY) && count--)
 		udelay(2);
@@ -956,7 +1004,7 @@ static int dwc_pause(struct dma_chan *chan)
 	unsigned long		flags;
 
 	spin_lock_irqsave(&dwc->lock, flags);
-	dwc_chan_pause(dwc);
+	dwc_chan_pause(dwc, false);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
 	return 0;
@@ -998,6 +1046,8 @@ static int dwc_terminate_all(struct dma_chan *chan)
 
 	clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
 
+	dwc_chan_pause(dwc, true);
+
 	dwc_chan_disable(dw, dwc);
 
 	dwc_chan_resume(dwc);
@@ -1090,6 +1140,32 @@ static void dwc_issue_pending(struct dma_chan *chan)
 
 /*----------------------------------------------------------------------*/
 
+/*
+ * Program FIFO size of channels.
+ *
+ * By default full FIFO (1024 bytes) is assigned to channel 0. Here we
+ * slice FIFO on equal parts between channels.
+ */
+static void idma32_fifo_partition(struct dw_dma *dw)
+{
+	u64 value = IDMA32C_FP_PSIZE_CH0(128) | IDMA32C_FP_PSIZE_CH1(128) |
+		    IDMA32C_FP_UPDATE;
+	u64 fifo_partition = 0;
+
+	if (!dw->pdata->is_idma32)
+		return;
+
+	/* Fill FIFO_PARTITION low bits (Channels 0..1, 4..5) */
+	fifo_partition |= value << 0;
+
+	/* Fill FIFO_PARTITION high bits (Channels 2..3, 6..7) */
+	fifo_partition |= value << 32;
+
+	/* Program FIFO Partition registers - 128 bytes for each channel */
+	idma32_writeq(dw, FIFO_PARTITION1, fifo_partition);
+	idma32_writeq(dw, FIFO_PARTITION0, fifo_partition);
+}
+
 static void dw_dma_off(struct dw_dma *dw)
 {
 	unsigned int i;
@@ -1509,7 +1585,12 @@ int dw_dma_probe(struct dw_dma_chip *chip)
 	/* Force dma off, just in case */
 	dw_dma_off(dw);
 
+	idma32_fifo_partition(dw);
+
 	/* Device and instance ID for IRQ and DMA pool */
+	if (pdata->is_idma32)
+		snprintf(dw->name, sizeof(dw->name), "idma32:dmac%d", chip->id);
+	else
 		snprintf(dw->name, sizeof(dw->name), "dw:dmac%d", chip->id);
 
 	/* Create a pool of consistent memory blocks for hardware descriptors */
@@ -1673,6 +1754,8 @@ int dw_dma_enable(struct dw_dma_chip *chip)
 {
 	struct dw_dma *dw = chip->dw;
 
+	idma32_fifo_partition(dw);
+
 	dw_dma_on(dw);
 	return 0;
 }

include/linux/platform_data/dma-dw.h

@@ -41,6 +41,7 @@ struct dw_dma_slave {
  * @is_private: The device channels should be marked as private and not for
  *	by the general purpose DMA channel allocator.
  * @is_memcpy: The device channels do support memory-to-memory transfers.
+ * @is_idma32: The type of the DMA controller is iDMA32
  * @chan_allocation_order: Allocate channels starting from 0 or 7
  * @chan_priority: Set channel priority increasing from 0 to 7 or 7 to 0.
  * @block_size: Maximum block size supported by the controller
@@ -53,6 +54,7 @@ struct dw_dma_platform_data {
 	unsigned int	nr_channels;
 	bool		is_private;
 	bool		is_memcpy;
+	bool		is_idma32;
 #define CHAN_ALLOCATION_ASCENDING	0	/* zero to seven */
 #define CHAN_ALLOCATION_DESCENDING	1	/* seven to zero */
 	unsigned char	chan_allocation_order;