Merge branch 'topic/univ_api' into for-linus

Documentation/dmaengine/client.txt

@@ -22,25 +22,14 @@ The slave DMA usage consists of following steps:
    Channel allocation is slightly different in the slave DMA context,
    client drivers typically need a channel from a particular DMA
    controller only and even in some cases a specific channel is desired.
-   To request a channel dma_request_channel() API is used.
+   To request a channel dma_request_chan() API is used.
 
    Interface:
-	struct dma_chan *dma_request_channel(dma_cap_mask_t mask,
+	struct dma_chan *dma_request_chan(struct device *dev, const char *name);
-			dma_filter_fn filter_fn,
-			void *filter_param);
-   where dma_filter_fn is defined as:
-	typedef bool (*dma_filter_fn)(struct dma_chan *chan, void *filter_param);
 
-   The 'filter_fn' parameter is optional, but highly recommended for
+   Which will find and return the 'name' DMA channel associated with the 'dev'
-   slave and cyclic channels as they typically need to obtain a specific
+   device. The association is done via DT, ACPI or board file based
-   DMA channel.
+   dma_slave_map matching table.
-
-   When the optional 'filter_fn' parameter is NULL, dma_request_channel()
-   simply returns the first channel that satisfies the capability mask.
-
-   Otherwise, the 'filter_fn' routine will be called once for each free
-   channel which has a capability in 'mask'.  'filter_fn' is expected to
-   return 'true' when the desired DMA channel is found.
 
    A channel allocated via this interface is exclusive to the caller,
    until dma_release_channel() is called.

drivers/dma/dmaengine.c

@@ -43,6 +43,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
 #include <linux/init.h>
 #include <linux/module.h>
@@ -512,7 +513,7 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
 {
 	struct dma_chan *chan;
 
-	if (!__dma_device_satisfies_mask(dev, mask)) {
+	if (mask && !__dma_device_satisfies_mask(dev, mask)) {
 		pr_debug("%s: wrong capabilities\n", __func__);
 		return NULL;
 	}
@@ -543,6 +544,42 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
 	return NULL;
 }
 
+static struct dma_chan *find_candidate(struct dma_device *device,
+				       const dma_cap_mask_t *mask,
+				       dma_filter_fn fn, void *fn_param)
+{
+	struct dma_chan *chan = private_candidate(mask, device, fn, fn_param);
+	int err;
+
+	if (chan) {
+		/* Found a suitable channel, try to grab, prep, and return it.
+		 * We first set DMA_PRIVATE to disable balance_ref_count as this
+		 * channel will not be published in the general-purpose
+		 * allocator
+		 */
+		dma_cap_set(DMA_PRIVATE, device->cap_mask);
+		device->privatecnt++;
+		err = dma_chan_get(chan);
+
+		if (err) {
+			if (err == -ENODEV) {
+				pr_debug("%s: %s module removed\n", __func__,
+					 dma_chan_name(chan));
+				list_del_rcu(&device->global_node);
+			} else
+				pr_debug("%s: failed to get %s: (%d)\n",
+					 __func__, dma_chan_name(chan), err);
+
+			if (--device->privatecnt == 0)
+				dma_cap_clear(DMA_PRIVATE, device->cap_mask);
+
+			chan = ERR_PTR(err);
+		}
+	}
+
+	return chan ? chan : ERR_PTR(-EPROBE_DEFER);
+}
+
 /**
  * dma_get_slave_channel - try to get specific channel exclusively
  * @chan: target channel
@@ -581,7 +618,6 @@ struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
 {
 	dma_cap_mask_t mask;
 	struct dma_chan *chan;
-	int err;
 
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
@@ -589,23 +625,11 @@ struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
 	/* lock against __dma_request_channel */
 	mutex_lock(&dma_list_mutex);
 
-	chan = private_candidate(&mask, device, NULL, NULL);
+	chan = find_candidate(device, &mask, NULL, NULL);
-	if (chan) {
-		dma_cap_set(DMA_PRIVATE, device->cap_mask);
-		device->privatecnt++;
-		err = dma_chan_get(chan);
-		if (err) {
-			pr_debug("%s: failed to get %s: (%d)\n",
-				__func__, dma_chan_name(chan), err);
-			chan = NULL;
-			if (--device->privatecnt == 0)
-				dma_cap_clear(DMA_PRIVATE, device->cap_mask);
-		}
-	}
 
 	mutex_unlock(&dma_list_mutex);
 
-	return chan;
+	return IS_ERR(chan) ? NULL : chan;
 }
 EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
 
@@ -622,35 +646,15 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
 {
 	struct dma_device *device, *_d;
 	struct dma_chan *chan = NULL;
-	int err;
 
 	/* Find a channel */
 	mutex_lock(&dma_list_mutex);
 	list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
-		chan = private_candidate(mask, device, fn, fn_param);
+		chan = find_candidate(device, mask, fn, fn_param);
-		if (chan) {
+		if (!IS_ERR(chan))
-			/* Found a suitable channel, try to grab, prep, and
+			break;
-			 * return it.  We first set DMA_PRIVATE to disable
-			 * balance_ref_count as this channel will not be
-			 * published in the general-purpose allocator
-			 */
-			dma_cap_set(DMA_PRIVATE, device->cap_mask);
-			device->privatecnt++;
-			err = dma_chan_get(chan);
 
-			if (err == -ENODEV) {
+		chan = NULL;
-				pr_debug("%s: %s module removed\n",
-					 __func__, dma_chan_name(chan));
-				list_del_rcu(&device->global_node);
-			} else if (err)
-				pr_debug("%s: failed to get %s: (%d)\n",
-					 __func__, dma_chan_name(chan), err);
-			else
-				break;
-			if (--device->privatecnt == 0)
-				dma_cap_clear(DMA_PRIVATE, device->cap_mask);
-			chan = NULL;
-		}
 	}
 	mutex_unlock(&dma_list_mutex);
 
@@ -663,27 +667,73 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
 }
 EXPORT_SYMBOL_GPL(__dma_request_channel);
 
+static const struct dma_slave_map *dma_filter_match(struct dma_device *device,
+						    const char *name,
+						    struct device *dev)
+{
+	int i;
+
+	if (!device->filter.mapcnt)
+		return NULL;
+
+	for (i = 0; i < device->filter.mapcnt; i++) {
+		const struct dma_slave_map *map = &device->filter.map[i];
+
+		if (!strcmp(map->devname, dev_name(dev)) &&
+		    !strcmp(map->slave, name))
+			return map;
+	}
+
+	return NULL;
+}
+
 /**
- * dma_request_slave_channel_reason - try to allocate an exclusive slave channel
+ * dma_request_chan - try to allocate an exclusive slave channel
  * @dev:	pointer to client device structure
  * @name:	slave channel name
  *
  * Returns pointer to appropriate DMA channel on success or an error pointer.
  */
-struct dma_chan *dma_request_slave_channel_reason(struct device *dev,
+struct dma_chan *dma_request_chan(struct device *dev, const char *name)
-						  const char *name)
 {
+	struct dma_device *d, *_d;
+	struct dma_chan *chan = NULL;
+
 	/* If device-tree is present get slave info from here */
 	if (dev->of_node)
-		return of_dma_request_slave_channel(dev->of_node, name);
+		chan = of_dma_request_slave_channel(dev->of_node, name);
 
 	/* If device was enumerated by ACPI get slave info from here */
-	if (ACPI_HANDLE(dev))
+	if (has_acpi_companion(dev) && !chan)
-		return acpi_dma_request_slave_chan_by_name(dev, name);
+		chan = acpi_dma_request_slave_chan_by_name(dev, name);
 
-	return ERR_PTR(-ENODEV);
+	if (chan) {
+		/* Valid channel found or requester need to be deferred */
+		if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
+			return chan;
+	}
+
+	/* Try to find the channel via the DMA filter map(s) */
+	mutex_lock(&dma_list_mutex);
+	list_for_each_entry_safe(d, _d, &dma_device_list, global_node) {
+		dma_cap_mask_t mask;
+		const struct dma_slave_map *map = dma_filter_match(d, name, dev);
+
+		if (!map)
+			continue;
+
+		dma_cap_zero(mask);
+		dma_cap_set(DMA_SLAVE, mask);
+
+		chan = find_candidate(d, &mask, d->filter.fn, map->param);
+		if (!IS_ERR(chan))
+			break;
+	}
+	mutex_unlock(&dma_list_mutex);
+
+	return chan ? chan : ERR_PTR(-EPROBE_DEFER);
 }
-EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason);
+EXPORT_SYMBOL_GPL(dma_request_chan);
 
 /**
  * dma_request_slave_channel - try to allocate an exclusive slave channel
@@ -695,17 +745,35 @@ EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason);
 struct dma_chan *dma_request_slave_channel(struct device *dev,
 					   const char *name)
 {
-	struct dma_chan *ch = dma_request_slave_channel_reason(dev, name);
+	struct dma_chan *ch = dma_request_chan(dev, name);
 	if (IS_ERR(ch))
 		return NULL;
 
-	dma_cap_set(DMA_PRIVATE, ch->device->cap_mask);
-	ch->device->privatecnt++;
-
 	return ch;
 }
 EXPORT_SYMBOL_GPL(dma_request_slave_channel);
 
+/**
+ * dma_request_chan_by_mask - allocate a channel satisfying certain capabilities
+ * @mask: capabilities that the channel must satisfy
+ *
+ * Returns pointer to appropriate DMA channel on success or an error pointer.
+ */
+struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask)
+{
+	struct dma_chan *chan;
+
+	if (!mask)
+		return ERR_PTR(-ENODEV);
+
+	chan = __dma_request_channel(mask, NULL, NULL);
+	if (!chan)
+		chan = ERR_PTR(-ENODEV);
+
+	return chan;
+}
+EXPORT_SYMBOL_GPL(dma_request_chan_by_mask);
+
 void dma_release_channel(struct dma_chan *chan)
 {
 	mutex_lock(&dma_list_mutex);

drivers/dma/edma.c

@@ -2297,6 +2297,10 @@ static int edma_probe(struct platform_device *pdev)
 		edma_set_chmap(&ecc->slave_chans[i], ecc->dummy_slot);
 	}
 
+	ecc->dma_slave.filter.map = info->slave_map;
+	ecc->dma_slave.filter.mapcnt = info->slavecnt;
+	ecc->dma_slave.filter.fn = edma_filter_fn;
+
 	ret = dma_async_device_register(&ecc->dma_slave);
 	if (ret) {
 		dev_err(dev, "slave ddev registration failed (%d)\n", ret);

drivers/dma/omap-dma.c

@@ -1203,6 +1203,10 @@ static int omap_dma_probe(struct platform_device *pdev)
 			return rc;
 	}
 
+	od->ddev.filter.map = od->plat->slave_map;
+	od->ddev.filter.mapcnt = od->plat->slavecnt;
+	od->ddev.filter.fn = omap_dma_filter_fn;
+
 	rc = dma_async_device_register(&od->ddev);
 	if (rc) {
 		pr_warn("OMAP-DMA: failed to register slave DMA engine device: %d\n",

include/linux/dmaengine.h

@@ -606,12 +606,39 @@ enum dmaengine_alignment {
 	DMAENGINE_ALIGN_64_BYTES = 6,
 };
 
+/**
+ * struct dma_slave_map - associates slave device and it's slave channel with
+ * parameter to be used by a filter function
+ * @devname: name of the device
+ * @slave: slave channel name
+ * @param: opaque parameter to pass to struct dma_filter.fn
+ */
+struct dma_slave_map {
+	const char *devname;
+	const char *slave;
+	void *param;
+};
+
+/**
+ * struct dma_filter - information for slave device/channel to filter_fn/param
+ * mapping
+ * @fn: filter function callback
+ * @mapcnt: number of slave device/channel in the map
+ * @map: array of channel to filter mapping data
+ */
+struct dma_filter {
+	dma_filter_fn fn;
+	int mapcnt;
+	const struct dma_slave_map *map;
+};
+
 /**
  * struct dma_device - info on the entity supplying DMA services
  * @chancnt: how many DMA channels are supported
  * @privatecnt: how many DMA channels are requested by dma_request_channel
  * @channels: the list of struct dma_chan
  * @global_node: list_head for global dma_device_list
+ * @filter: information for device/slave to filter function/param mapping
  * @cap_mask: one or more dma_capability flags
  * @max_xor: maximum number of xor sources, 0 if no capability
  * @max_pq: maximum number of PQ sources and PQ-continue capability
@@ -667,6 +694,7 @@ struct dma_device {
 	unsigned int privatecnt;
 	struct list_head channels;
 	struct list_head global_node;
+	struct dma_filter filter;
 	dma_cap_mask_t  cap_mask;
 	unsigned short max_xor;
 	unsigned short max_pq;
@@ -1142,9 +1170,11 @@ enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);
 void dma_issue_pending_all(void);
 struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
 					dma_filter_fn fn, void *fn_param);
-struct dma_chan *dma_request_slave_channel_reason(struct device *dev,
-						  const char *name);
 struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name);
+
+struct dma_chan *dma_request_chan(struct device *dev, const char *name);
+struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask);
+
 void dma_release_channel(struct dma_chan *chan);
 int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps);
 #else
@@ -1168,16 +1198,21 @@ static inline struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
 {
 	return NULL;
 }
-static inline struct dma_chan *dma_request_slave_channel_reason(
-					struct device *dev, const char *name)
-{
-	return ERR_PTR(-ENODEV);
-}
 static inline struct dma_chan *dma_request_slave_channel(struct device *dev,
 							 const char *name)
 {
 	return NULL;
 }
+static inline struct dma_chan *dma_request_chan(struct device *dev,
+						const char *name)
+{
+	return ERR_PTR(-ENODEV);
+}
+static inline struct dma_chan *dma_request_chan_by_mask(
+						const dma_cap_mask_t *mask)
+{
+	return ERR_PTR(-ENODEV);
+}
 static inline void dma_release_channel(struct dma_chan *chan)
 {
 }
@@ -1188,6 +1223,8 @@ static inline int dma_get_slave_caps(struct dma_chan *chan,
 }
 #endif
 
+#define dma_request_slave_channel_reason(dev, name) dma_request_chan(dev, name)
+
 static inline int dmaengine_desc_set_reuse(struct dma_async_tx_descriptor *tx)
 {
 	struct dma_slave_caps caps;

include/linux/omap-dma.h

@@ -267,6 +267,9 @@ struct omap_dma_reg {
 	u8	type;
 };
 
+#define SDMA_FILTER_PARAM(hw_req)	((int[]) { (hw_req) })
+struct dma_slave_map;
+
 /* System DMA platform data structure */
 struct omap_system_dma_plat_info {
 	const struct omap_dma_reg *reg_map;
@@ -278,6 +281,9 @@ struct omap_system_dma_plat_info {
 	void (*clear_dma)(int lch);
 	void (*dma_write)(u32 val, int reg, int lch);
 	u32 (*dma_read)(int reg, int lch);
+
+	const struct dma_slave_map *slave_map;
+	int slavecnt;
 };
 
 #ifdef CONFIG_ARCH_OMAP2PLUS

include/linux/platform_data/edma.h

@@ -53,12 +53,16 @@ enum dma_event_q {
 #define EDMA_CTLR(i)			((i) >> 16)
 #define EDMA_CHAN_SLOT(i)		((i) & 0xffff)
 
+#define EDMA_FILTER_PARAM(ctlr, chan)	((int[]) { EDMA_CTLR_CHAN(ctlr, chan) })
+
 struct edma_rsv_info {
 
 	const s16	(*rsv_chans)[2];
 	const s16	(*rsv_slots)[2];
 };
 
+struct dma_slave_map;
+
 /* platform_data for EDMA driver */
 struct edma_soc_info {
 	/*
@@ -76,6 +80,9 @@ struct edma_soc_info {
 
 	s8	(*queue_priority_mapping)[2];
 	const s16	(*xbar_chans)[2];
+
+	const struct dma_slave_map *slave_map;
+	int slavecnt;
 };
 
 #endif