Merge branch 'next' of git://git.infradead.org/users/vkoul/slave-dma

Pull second set of slave-dmaengine updates from Vinod Koul:
 "Arnd's patch moves the dw_dmac to use generic DMA binding.  I agreed
  to merge this late as it will avoid the conflicts between trees.

  The second patch from Matt adding a dma_request_slave_channel_compat
  API was supposed to be picked up, but somehow never got picked up.
  Some patches dependent on this are already in -next :("

* 'next' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dw_dmac: move to generic DMA binding
  dmaengine: add dma_request_slave_channel_compat()

Documentation/devicetree/bindings/dma/snps-dma.txt

@@ -3,59 +3,61 @@
 Required properties:
 - compatible: "snps,dma-spear1340"
 - reg: Address range of the DMAC registers
-- interrupt-parent: Should be the phandle for the interrupt controller
-  that services interrupts for this device
 - interrupt: Should contain the DMAC interrupt number
-- nr_channels: Number of channels supported by hardware
+- dma-channels: Number of channels supported by hardware
-- is_private: The device channels should be marked as private and not for by the
+- dma-requests: Number of DMA request lines supported, up to 16
-  general purpose DMA channel allocator. False if not passed.
+- dma-masters: Number of AHB masters supported by the controller
+- #dma-cells: must be <3>
 - chan_allocation_order: order of allocation of channel, 0 (default): ascending,
   1: descending
 - chan_priority: priority of channels. 0 (default): increase from chan 0->n, 1:
   increase from chan n->0
 - block_size: Maximum block size supported by the controller
-- nr_masters: Number of AHB masters supported by the controller
 - data_width: Maximum data width supported by hardware per AHB master
   (0 - 8bits, 1 - 16bits, ..., 5 - 256bits)
-- slave_info:
+
-	- bus_id: name of this device channel, not just a device name since
+
-	  devices may have more than one channel e.g. "foo_tx". For using the
+Optional properties:
-	  dw_generic_filter(), slave drivers must pass exactly this string as
+- interrupt-parent: Should be the phandle for the interrupt controller
-	  param to filter function.
+  that services interrupts for this device
-	- cfg_hi: Platform-specific initializer for the CFG_HI register
+- is_private: The device channels should be marked as private and not for by the
-	- cfg_lo: Platform-specific initializer for the CFG_LO register
+  general purpose DMA channel allocator. False if not passed.
-	- src_master: src master for transfers on allocated channel.
-	- dst_master: dest master for transfers on allocated channel.
 
 Example:
 
-	dma@fc000000 {
+	dmahost: dma@fc000000 {
 		compatible = "snps,dma-spear1340";
 		reg = <0xfc000000 0x1000>;
 		interrupt-parent = <&vic1>;
 		interrupts = <12>;
 
-		nr_channels = <8>;
+		dma-channels = <8>;
+		dma-requests = <16>;
+		dma-masters = <2>;
+		#dma-cells = <3>;
 		chan_allocation_order = <1>;
 		chan_priority = <1>;
 		block_size = <0xfff>;
-		nr_masters = <2>;
 		data_width = <3 3 0 0>;
-
+	};
-		slave_info {
+
-			uart0-tx {
+DMA clients connected to the Designware DMA controller must use the format
-				bus_id = "uart0-tx";
+described in the dma.txt file, using a four-cell specifier for each channel.
-				cfg_hi = <0x4000>;	/* 0x8 << 11 */
+The four cells in order are:
-				cfg_lo = <0>;
+
-				src_master = <0>;
+1. A phandle pointing to the DMA controller
-				dst_master = <1>;
+2. The DMA request line number
-			};
+3. Source master for transfers on allocated channel
-			spi0-tx {
+4. Destination master for transfers on allocated channel
-				bus_id = "spi0-tx";
+
-				cfg_hi = <0x2000>;	/* 0x4 << 11 */
+Example:
-				cfg_lo = <0>;
+	
-				src_master = <0>;
+	serial@e0000000 {
-				dst_master = <0>;
+		compatible = "arm,pl011", "arm,primecell";
-			};
+		reg = <0xe0000000 0x1000>;
-		};
+		interrupts = <0 35 0x4>;
+		status = "disabled";
+		dmas = <&dmahost 12 0 1>,
+			<&dmahost 13 0 1 0>;
+		dma-names = "rx", "rx";
 	};

drivers/dma/dw_dmac.c

@@ -20,6 +20,7 @@
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/of.h>
+#include <linux/of_dma.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -171,7 +172,13 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
 	if (dwc->initialized == true)
 		return;
 
-	if (dws) {
+	if (dws && dws->cfg_hi == ~0 && dws->cfg_lo == ~0) {
+		/* autoconfigure based on request line from DT */
+		if (dwc->direction == DMA_MEM_TO_DEV)
+			cfghi = DWC_CFGH_DST_PER(dwc->request_line);
+		else if (dwc->direction == DMA_DEV_TO_MEM)
+			cfghi = DWC_CFGH_SRC_PER(dwc->request_line);
+	} else if (dws) {
 		/*
 		 * We need controller-specific data to set up slave
 		 * transfers.
@@ -1226,49 +1233,64 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
 	dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
 }
 
-bool dw_dma_generic_filter(struct dma_chan *chan, void *param)
+struct dw_dma_filter_args {
+	struct dw_dma *dw;
+	unsigned int req;
+	unsigned int src;
+	unsigned int dst;
+};
+
+static bool dw_dma_generic_filter(struct dma_chan *chan, void *param)
 {
+	struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
 	struct dw_dma *dw = to_dw_dma(chan->device);
-	static struct dw_dma *last_dw;
+	struct dw_dma_filter_args *fargs = param;
-	static char *last_bus_id;
+	struct dw_dma_slave *dws = &dwc->slave;
-	int i = -1;
 
-	/*
+	/* ensure the device matches our channel */
-	 * dmaengine framework calls this routine for all channels of all dma
+        if (chan->device != &fargs->dw->dma)
-	 * controller, until true is returned. If 'param' bus_id is not
+                return false;
-	 * registered with a dma controller (dw), then there is no need of
-	 * running below function for all channels of dw.
-	 *
-	 * This block of code does this by saving the parameters of last
-	 * failure. If dw and param are same, i.e. trying on same dw with
-	 * different channel, return false.
-	 */
-	if ((last_dw == dw) && (last_bus_id == param))
-		return false;
-	/*
-	 * Return true:
-	 * - If dw_dma's platform data is not filled with slave info, then all
-	 *   dma controllers are fine for transfer.
-	 * - Or if param is NULL
-	 */
-	if (!dw->sd || !param)
-		return true;
 
-	while (++i < dw->sd_count) {
+	dws->dma_dev	= dw->dma.dev;
-		if (!strcmp(dw->sd[i].bus_id, param)) {
+	dws->cfg_hi	= ~0;
-			chan->private = &dw->sd[i];
+	dws->cfg_lo	= ~0;
-			last_dw = NULL;
+	dws->src_master	= fargs->src;
-			last_bus_id = NULL;
+	dws->dst_master	= fargs->dst;
 
-			return true;
+	dwc->request_line = fargs->req;
-		}
-	}
 
-	last_dw = dw;
+	chan->private = dws;
-	last_bus_id = param;
+
-	return false;
+	return true;
+}
+
+static struct dma_chan *dw_dma_xlate(struct of_phandle_args *dma_spec,
+					 struct of_dma *ofdma)
+{
+	struct dw_dma *dw = ofdma->of_dma_data;
+	struct dw_dma_filter_args fargs = {
+		.dw = dw,
+	};
+	dma_cap_mask_t cap;
+
+	if (dma_spec->args_count != 3)
+		return NULL;
+
+	fargs.req = be32_to_cpup(dma_spec->args+0);
+	fargs.src = be32_to_cpup(dma_spec->args+1);
+	fargs.dst = be32_to_cpup(dma_spec->args+2);
+
+	if (WARN_ON(fargs.req >= DW_DMA_MAX_NR_REQUESTS ||
+		    fargs.src >= dw->nr_masters ||
+		    fargs.dst >= dw->nr_masters))
+		return NULL;
+
+	dma_cap_zero(cap);
+	dma_cap_set(DMA_SLAVE, cap);
+
+	/* TODO: there should be a simpler way to do this */
+	return dma_request_channel(cap, dw_dma_generic_filter, &fargs);
 }
-EXPORT_SYMBOL(dw_dma_generic_filter);
 
 /* --------------------- Cyclic DMA API extensions -------------------- */
 
@@ -1554,9 +1576,8 @@ static void dw_dma_off(struct dw_dma *dw)
 static struct dw_dma_platform_data *
 dw_dma_parse_dt(struct platform_device *pdev)
 {
-	struct device_node *sn, *cn, *np = pdev->dev.of_node;
+	struct device_node *np = pdev->dev.of_node;
 	struct dw_dma_platform_data *pdata;
-	struct dw_dma_slave *sd;
 	u32 tmp, arr[4];
 
 	if (!np) {
@@ -1568,7 +1589,7 @@ dw_dma_parse_dt(struct platform_device *pdev)
 	if (!pdata)
 		return NULL;
 
-	if (of_property_read_u32(np, "nr_channels", &pdata->nr_channels))
+	if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels))
 		return NULL;
 
 	if (of_property_read_bool(np, "is_private"))
@@ -1583,7 +1604,7 @@ dw_dma_parse_dt(struct platform_device *pdev)
 	if (!of_property_read_u32(np, "block_size", &tmp))
 		pdata->block_size = tmp;
 
-	if (!of_property_read_u32(np, "nr_masters", &tmp)) {
+	if (!of_property_read_u32(np, "dma-masters", &tmp)) {
 		if (tmp > 4)
 			return NULL;
 
@@ -1595,36 +1616,6 @@ dw_dma_parse_dt(struct platform_device *pdev)
 		for (tmp = 0; tmp < pdata->nr_masters; tmp++)
 			pdata->data_width[tmp] = arr[tmp];
 
-	/* parse slave data */
-	sn = of_find_node_by_name(np, "slave_info");
-	if (!sn)
-		return pdata;
-
-	/* calculate number of slaves */
-	tmp = of_get_child_count(sn);
-	if (!tmp)
-		return NULL;
-
-	sd = devm_kzalloc(&pdev->dev, sizeof(*sd) * tmp, GFP_KERNEL);
-	if (!sd)
-		return NULL;
-
-	pdata->sd = sd;
-	pdata->sd_count = tmp;
-
-	for_each_child_of_node(sn, cn) {
-		sd->dma_dev = &pdev->dev;
-		of_property_read_string(cn, "bus_id", &sd->bus_id);
-		of_property_read_u32(cn, "cfg_hi", &sd->cfg_hi);
-		of_property_read_u32(cn, "cfg_lo", &sd->cfg_lo);
-		if (!of_property_read_u32(cn, "src_master", &tmp))
-			sd->src_master = tmp;
-
-		if (!of_property_read_u32(cn, "dst_master", &tmp))
-			sd->dst_master = tmp;
-		sd++;
-	}
-
 	return pdata;
 }
 #else
@@ -1705,8 +1696,6 @@ static int dw_probe(struct platform_device *pdev)
 	clk_prepare_enable(dw->clk);
 
 	dw->regs = regs;
-	dw->sd = pdata->sd;
-	dw->sd_count = pdata->sd_count;
 
 	/* get hardware configuration parameters */
 	if (autocfg) {
@@ -1837,6 +1826,14 @@ static int dw_probe(struct platform_device *pdev)
 
 	dma_async_device_register(&dw->dma);
 
+	if (pdev->dev.of_node) {
+		err = of_dma_controller_register(pdev->dev.of_node,
+						 dw_dma_xlate, dw);
+		if (err && err != -ENODEV)
+			dev_err(&pdev->dev,
+				"could not register of_dma_controller\n");
+	}
+
 	return 0;
 }
 
@@ -1845,6 +1842,8 @@ static int dw_remove(struct platform_device *pdev)
 	struct dw_dma		*dw = platform_get_drvdata(pdev);
 	struct dw_dma_chan	*dwc, *_dwc;
 
+	if (pdev->dev.of_node)
+		of_dma_controller_free(pdev->dev.of_node);
 	dw_dma_off(dw);
 	dma_async_device_unregister(&dw->dma);
 

drivers/dma/dw_dmac_regs.h

@@ -13,6 +13,7 @@
 #include <linux/dw_dmac.h>
 
 #define DW_DMA_MAX_NR_CHANNELS	8
+#define DW_DMA_MAX_NR_REQUESTS	16
 
 /* flow controller */
 enum dw_dma_fc {
@@ -211,6 +212,8 @@ struct dw_dma_chan {
 	/* hardware configuration */
 	unsigned int		block_size;
 	bool			nollp;
+	unsigned int		request_line;
+	struct dw_dma_slave	slave;
 
 	/* configuration passed via DMA_SLAVE_CONFIG */
 	struct dma_slave_config dma_sconfig;
@@ -239,10 +242,6 @@ struct dw_dma {
 	struct tasklet_struct	tasklet;
 	struct clk		*clk;
 
-	/* slave information */
-	struct dw_dma_slave	*sd;
-	unsigned int		sd_count;
-
 	u8			all_chan_mask;
 
 	/* hardware configuration */

include/linux/dmaengine.h

@@ -1001,6 +1001,22 @@ void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
 struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type);
 struct dma_chan *net_dma_find_channel(void);
 #define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
+#define dma_request_slave_channel_compat(mask, x, y, dev, name) \
+	__dma_request_slave_channel_compat(&(mask), x, y, dev, name)
+
+static inline struct dma_chan
+*__dma_request_slave_channel_compat(dma_cap_mask_t *mask, dma_filter_fn fn,
+				  void *fn_param, struct device *dev,
+				  char *name)
+{
+	struct dma_chan *chan;
+
+	chan = dma_request_slave_channel(dev, name);
+	if (chan)
+		return chan;
+
+	return __dma_request_channel(mask, fn, fn_param);
+}
 
 /* --- Helper iov-locking functions --- */
 

include/linux/dw_dmac.h

@@ -27,7 +27,6 @@
  */
 struct dw_dma_slave {
 	struct device		*dma_dev;
-	const char		*bus_id;
 	u32			cfg_hi;
 	u32			cfg_lo;
 	u8			src_master;
@@ -60,9 +59,6 @@ struct dw_dma_platform_data {
 	unsigned short	block_size;
 	unsigned char	nr_masters;
 	unsigned char	data_width[4];
-
-	struct dw_dma_slave *sd;
-	unsigned int sd_count;
 };
 
 /* bursts size */
@@ -114,6 +110,5 @@ void dw_dma_cyclic_stop(struct dma_chan *chan);
 dma_addr_t dw_dma_get_src_addr(struct dma_chan *chan);
 
 dma_addr_t dw_dma_get_dst_addr(struct dma_chan *chan);
-bool dw_dma_generic_filter(struct dma_chan *chan, void *param);
 
 #endif /* DW_DMAC_H */