Merge remote-tracking branch 'regmap/topic/async' into regmap-next

drivers/base/regmap/internal.h

@@ -16,6 +16,7 @@
 #include <linux/regmap.h>
 #include <linux/fs.h>
 #include <linux/list.h>
+#include <linux/wait.h>
 
 struct regmap;
 struct regcache_ops;
@@ -39,6 +40,13 @@ struct regmap_format {
 	unsigned int (*parse_val)(void *buf);
 };
 
+struct regmap_async {
+	struct list_head list;
+	struct work_struct cleanup;
+	struct regmap *map;
+	void *work_buf;
+};
+
 struct regmap {
 	struct mutex mutex;
 	spinlock_t spinlock;
@@ -53,6 +61,11 @@ struct regmap {
 	void *bus_context;
 	const char *name;
 
+	spinlock_t async_lock;
+	wait_queue_head_t async_waitq;
+	struct list_head async_list;
+	int async_ret;
+
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debugfs;
 	const char *debugfs_name;
@@ -74,6 +87,9 @@ struct regmap {
 	const struct regmap_access_table *volatile_table;
 	const struct regmap_access_table *precious_table;
 
+	int (*reg_read)(void *context, unsigned int reg, unsigned int *val);
+	int (*reg_write)(void *context, unsigned int reg, unsigned int val);
+
 	u8 read_flag_mask;
 	u8 write_flag_mask;
 
@@ -175,6 +191,8 @@ bool regcache_set_val(void *base, unsigned int idx,
 		      unsigned int val, unsigned int word_size);
 int regcache_lookup_reg(struct regmap *map, unsigned int reg);
 
+void regmap_async_complete_cb(struct regmap_async *async, int ret);
+
 extern struct regcache_ops regcache_rbtree_ops;
 extern struct regcache_ops regcache_lzo_ops;
 

drivers/base/regmap/regmap-spi.c

@@ -15,6 +15,21 @@
 #include <linux/init.h>
 #include <linux/module.h>
 
+#include "internal.h"
+
+struct regmap_async_spi {
+	struct regmap_async core;
+	struct spi_message m;
+	struct spi_transfer t[2];
+};
+
+static void regmap_spi_complete(void *data)
+{
+	struct regmap_async_spi *async = data;
+
+	regmap_async_complete_cb(&async->core, async->m.status);
+}
+
 static int regmap_spi_write(void *context, const void *data, size_t count)
 {
 	struct device *dev = context;
@@ -40,6 +55,43 @@ static int regmap_spi_gather_write(void *context,
 	return spi_sync(spi, &m);
 }
 
+static int regmap_spi_async_write(void *context,
+				  const void *reg, size_t reg_len,
+				  const void *val, size_t val_len,
+				  struct regmap_async *a)
+{
+	struct regmap_async_spi *async = container_of(a,
+						      struct regmap_async_spi,
+						      core);
+	struct device *dev = context;
+	struct spi_device *spi = to_spi_device(dev);
+
+	async->t[0].tx_buf = reg;
+	async->t[0].len = reg_len;
+	async->t[1].tx_buf = val;
+	async->t[1].len = val_len;
+
+	spi_message_init(&async->m);
+	spi_message_add_tail(&async->t[0], &async->m);
+	spi_message_add_tail(&async->t[1], &async->m);
+
+	async->m.complete = regmap_spi_complete;
+	async->m.context = async;
+
+	return spi_async(spi, &async->m);
+}
+
+static struct regmap_async *regmap_spi_async_alloc(void)
+{
+	struct regmap_async_spi *async_spi;
+
+	async_spi = kzalloc(sizeof(*async_spi), GFP_KERNEL);
+	if (!async_spi)
+		return NULL;
+
+	return &async_spi->core;
+}
+
 static int regmap_spi_read(void *context,
 			   const void *reg, size_t reg_size,
 			   void *val, size_t val_size)
@@ -53,6 +105,8 @@ static int regmap_spi_read(void *context,
 static struct regmap_bus regmap_spi = {
 	.write = regmap_spi_write,
 	.gather_write = regmap_spi_gather_write,
+	.async_write = regmap_spi_async_write,
+	.async_alloc = regmap_spi_async_alloc,
 	.read = regmap_spi_read,
 	.read_flag_mask = 0x80,
 };

drivers/base/regmap/regmap.c

@@ -16,6 +16,7 @@
 #include <linux/mutex.h>
 #include <linux/err.h>
 #include <linux/rbtree.h>
+#include <linux/sched.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/regmap.h>
@@ -34,6 +35,22 @@ static int _regmap_update_bits(struct regmap *map, unsigned int reg,
 			       unsigned int mask, unsigned int val,
 			       bool *change);
 
+static int _regmap_bus_read(void *context, unsigned int reg,
+			    unsigned int *val);
+static int _regmap_bus_formatted_write(void *context, unsigned int reg,
+				       unsigned int val);
+static int _regmap_bus_raw_write(void *context, unsigned int reg,
+				 unsigned int val);
+
+static void async_cleanup(struct work_struct *work)
+{
+	struct regmap_async *async = container_of(work, struct regmap_async,
+						  cleanup);
+
+	kfree(async->work_buf);
+	kfree(async);
+}
+
 bool regmap_reg_in_ranges(unsigned int reg,
 			  const struct regmap_range *ranges,
 			  unsigned int nranges)
@@ -423,6 +440,10 @@ struct regmap *regmap_init(struct device *dev,
 	map->cache_type = config->cache_type;
 	map->name = config->name;
 
+	spin_lock_init(&map->async_lock);
+	INIT_LIST_HEAD(&map->async_list);
+	init_waitqueue_head(&map->async_waitq);
+
 	if (config->read_flag_mask || config->write_flag_mask) {
 		map->read_flag_mask = config->read_flag_mask;
 		map->write_flag_mask = config->write_flag_mask;
@@ -430,6 +451,8 @@ struct regmap *regmap_init(struct device *dev,
 		map->read_flag_mask = bus->read_flag_mask;
 	}
 
+	map->reg_read = _regmap_bus_read;
+
 	reg_endian = config->reg_format_endian;
 	if (reg_endian == REGMAP_ENDIAN_DEFAULT)
 		reg_endian = bus->reg_format_endian_default;
@@ -581,6 +604,11 @@ struct regmap *regmap_init(struct device *dev,
 		goto err_map;
 	}
 
+	if (map->format.format_write)
+		map->reg_write = _regmap_bus_formatted_write;
+	else if (map->format.format_val)
+		map->reg_write = _regmap_bus_raw_write;
+
 	map->range_tree = RB_ROOT;
 	for (i = 0; i < config->num_ranges; i++) {
 		const struct regmap_range_cfg *range_cfg = &config->ranges[i];
@@ -876,10 +904,13 @@ static int _regmap_select_page(struct regmap *map, unsigned int *reg,
 }
 
 static int _regmap_raw_write(struct regmap *map, unsigned int reg,
-			     const void *val, size_t val_len)
+			     const void *val, size_t val_len, bool async)
 {
 	struct regmap_range_node *range;
+	unsigned long flags;
 	u8 *u8 = map->work_buf;
+	void *work_val = map->work_buf + map->format.reg_bytes +
+		map->format.pad_bytes;
 	void *buf;
 	int ret = -ENOTSUPP;
 	size_t len;
@@ -924,7 +955,7 @@ static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 			dev_dbg(map->dev, "Writing window %d/%zu\n",
 				win_residue, val_len / map->format.val_bytes);
 			ret = _regmap_raw_write(map, reg, val, win_residue *
-						map->format.val_bytes);
+						map->format.val_bytes, async);
 			if (ret != 0)
 				return ret;
 
@@ -947,6 +978,50 @@ static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 
 	u8[0] |= map->write_flag_mask;
 
+	if (async && map->bus->async_write) {
+		struct regmap_async *async = map->bus->async_alloc();
+		if (!async)
+			return -ENOMEM;
+
+		async->work_buf = kzalloc(map->format.buf_size,
+					  GFP_KERNEL | GFP_DMA);
+		if (!async->work_buf) {
+			kfree(async);
+			return -ENOMEM;
+		}
+
+		INIT_WORK(&async->cleanup, async_cleanup);
+		async->map = map;
+
+		/* If the caller supplied the value we can use it safely. */
+		memcpy(async->work_buf, map->work_buf, map->format.pad_bytes +
+		       map->format.reg_bytes + map->format.val_bytes);
+		if (val == work_val)
+			val = async->work_buf + map->format.pad_bytes +
+				map->format.reg_bytes;
+
+		spin_lock_irqsave(&map->async_lock, flags);
+		list_add_tail(&async->list, &map->async_list);
+		spin_unlock_irqrestore(&map->async_lock, flags);
+
+		ret = map->bus->async_write(map->bus_context, async->work_buf,
+					    map->format.reg_bytes +
+					    map->format.pad_bytes,
+					    val, val_len, async);
+
+		if (ret != 0) {
+			dev_err(map->dev, "Failed to schedule write: %d\n",
+				ret);
+
+			spin_lock_irqsave(&map->async_lock, flags);
+			list_del(&async->list);
+			spin_unlock_irqrestore(&map->async_lock, flags);
+
+			kfree(async->work_buf);
+			kfree(async);
+		}
+	}
+
 	trace_regmap_hw_write_start(map->dev, reg,
 				    val_len / map->format.val_bytes);
 
@@ -954,8 +1029,7 @@ static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 	 * send the work_buf directly, otherwise try to do a gather
 	 * write.
 	 */
-	if (val == (map->work_buf + map->format.pad_bytes +
-		    map->format.reg_bytes))
+	if (val == work_val)
 		ret = map->bus->write(map->bus_context, map->work_buf,
 				      map->format.reg_bytes +
 				      map->format.pad_bytes +
@@ -987,12 +1061,54 @@ static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 	return ret;
 }
 
+static int _regmap_bus_formatted_write(void *context, unsigned int reg,
+				       unsigned int val)
+{
+	int ret;
+	struct regmap_range_node *range;
+	struct regmap *map = context;
+
+	BUG_ON(!map->format.format_write);
+
+	range = _regmap_range_lookup(map, reg);
+	if (range) {
+		ret = _regmap_select_page(map, &reg, range, 1);
+		if (ret != 0)
+			return ret;
+	}
+
+	map->format.format_write(map, reg, val);
+
+	trace_regmap_hw_write_start(map->dev, reg, 1);
+
+	ret = map->bus->write(map->bus_context, map->work_buf,
+			      map->format.buf_size);
+
+	trace_regmap_hw_write_done(map->dev, reg, 1);
+
+	return ret;
+}
+
+static int _regmap_bus_raw_write(void *context, unsigned int reg,
+				 unsigned int val)
+{
+	struct regmap *map = context;
+
+	BUG_ON(!map->format.format_val);
+
+	map->format.format_val(map->work_buf + map->format.reg_bytes
+			       + map->format.pad_bytes, val, 0);
+	return _regmap_raw_write(map, reg,
+				 map->work_buf +
+				 map->format.reg_bytes +
+				 map->format.pad_bytes,
+				 map->format.val_bytes, false);
+}
+
 int _regmap_write(struct regmap *map, unsigned int reg,
 		  unsigned int val)
 {
-	struct regmap_range_node *range;
 	int ret;
-	BUG_ON(!map->format.format_write && !map->format.format_val);
 
 	if (!map->cache_bypass && map->format.format_write) {
 		ret = regcache_write(map, reg, val);
@@ -1011,33 +1127,7 @@ int _regmap_write(struct regmap *map, unsigned int reg,
 
 	trace_regmap_reg_write(map->dev, reg, val);
 
-	if (map->format.format_write) {
-		range = _regmap_range_lookup(map, reg);
-		if (range) {
-			ret = _regmap_select_page(map, &reg, range, 1);
-			if (ret != 0)
-				return ret;
-		}
-
-		map->format.format_write(map, reg, val);
-
-		trace_regmap_hw_write_start(map->dev, reg, 1);
-
-		ret = map->bus->write(map->bus_context, map->work_buf,
-				      map->format.buf_size);
-
-		trace_regmap_hw_write_done(map->dev, reg, 1);
-
-		return ret;
-	} else {
-		map->format.format_val(map->work_buf + map->format.reg_bytes
-				       + map->format.pad_bytes, val, 0);
-		return _regmap_raw_write(map, reg,
-					 map->work_buf +
-					 map->format.reg_bytes +
-					 map->format.pad_bytes,
-					 map->format.val_bytes);
-	}
+	return map->reg_write(map, reg, val);
 }
 
 /**
@@ -1095,7 +1185,7 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
 
 	map->lock(map->lock_arg);
 
-	ret = _regmap_raw_write(map, reg, val, val_len);
+	ret = _regmap_raw_write(map, reg, val, val_len, false);
 
 	map->unlock(map->lock_arg);
 
@@ -1151,14 +1241,15 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 	if (map->use_single_rw) {
 		for (i = 0; i < val_count; i++) {
 			ret = regmap_raw_write(map,
-						reg + (i * map->reg_stride),
-						val + (i * val_bytes),
-						val_bytes);
+					       reg + (i * map->reg_stride),
+					       val + (i * val_bytes),
+					       val_bytes);
 			if (ret != 0)
 				return ret;
 		}
 	} else {
-		ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count);
+		ret = _regmap_raw_write(map, reg, wval, val_bytes * val_count,
+					false);
 	}
 
 	if (val_bytes != 1)
@@ -1170,6 +1261,48 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 }
 EXPORT_SYMBOL_GPL(regmap_bulk_write);
 
+/**
+ * regmap_raw_write_async(): Write raw values to one or more registers
+ *                           asynchronously
+ *
+ * @map: Register map to write to
+ * @reg: Initial register to write to
+ * @val: Block of data to be written, laid out for direct transmission to the
+ *       device.  Must be valid until regmap_async_complete() is called.
+ * @val_len: Length of data pointed to by val.
+ *
+ * This function is intended to be used for things like firmware
+ * download where a large block of data needs to be transferred to the
+ * device.  No formatting will be done on the data provided.
+ *
+ * If supported by the underlying bus the write will be scheduled
+ * asynchronously, helping maximise I/O speed on higher speed buses
+ * like SPI.  regmap_async_complete() can be called to ensure that all
+ * asynchrnous writes have been completed.
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_raw_write_async(struct regmap *map, unsigned int reg,
+			   const void *val, size_t val_len)
+{
+	int ret;
+
+	if (val_len % map->format.val_bytes)
+		return -EINVAL;
+	if (reg % map->reg_stride)
+		return -EINVAL;
+
+	map->lock(map->lock_arg);
+
+	ret = _regmap_raw_write(map, reg, val, val_len, true);
+
+	map->unlock(map->lock_arg);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_raw_write_async);
+
 static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 			    unsigned int val_len)
 {
@@ -1208,10 +1341,27 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 	return ret;
 }
 
+static int _regmap_bus_read(void *context, unsigned int reg,
+			    unsigned int *val)
+{
+	int ret;
+	struct regmap *map = context;
+
+	if (!map->format.parse_val)
+		return -EINVAL;
+
+	ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
+	if (ret == 0)
+		*val = map->format.parse_val(map->work_buf);
+
+	return ret;
+}
+
 static int _regmap_read(struct regmap *map, unsigned int reg,
 			unsigned int *val)
 {
 	int ret;
+	BUG_ON(!map->reg_read);
 
 	if (!map->cache_bypass) {
 		ret = regcache_read(map, reg, val);
@@ -1219,26 +1369,21 @@ static int _regmap_read(struct regmap *map, unsigned int reg,
 			return 0;
 	}
 
-	if (!map->format.parse_val)
-		return -EINVAL;
-
 	if (map->cache_only)
 		return -EBUSY;
 
-	ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
+	ret = map->reg_read(map, reg, val);
 	if (ret == 0) {
-		*val = map->format.parse_val(map->work_buf);
-
 #ifdef LOG_DEVICE
 		if (strcmp(dev_name(map->dev), LOG_DEVICE) == 0)
 			dev_info(map->dev, "%x => %x\n", reg, *val);
 #endif
 
 		trace_regmap_reg_read(map->dev, reg, *val);
-	}
 
-	if (ret == 0 && !map->cache_bypass)
-		regcache_write(map, reg, *val);
+		if (!map->cache_bypass)
+			regcache_write(map, reg, *val);
+	}
 
 	return ret;
 }
@@ -1456,6 +1601,68 @@ int regmap_update_bits_check(struct regmap *map, unsigned int reg,
 }
 EXPORT_SYMBOL_GPL(regmap_update_bits_check);
 
+void regmap_async_complete_cb(struct regmap_async *async, int ret)
+{
+	struct regmap *map = async->map;
+	bool wake;
+
+	spin_lock(&map->async_lock);
+
+	list_del(&async->list);
+	wake = list_empty(&map->async_list);
+
+	if (ret != 0)
+		map->async_ret = ret;
+
+	spin_unlock(&map->async_lock);
+
+	schedule_work(&async->cleanup);
+
+	if (wake)
+		wake_up(&map->async_waitq);
+}
+EXPORT_SYMBOL_GPL(regmap_async_complete_cb);
+
+static int regmap_async_is_done(struct regmap *map)
+{
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&map->async_lock, flags);
+	ret = list_empty(&map->async_list);
+	spin_unlock_irqrestore(&map->async_lock, flags);
+
+	return ret;
+}
+
+/**
+ * regmap_async_complete: Ensure all asynchronous I/O has completed.
+ *
+ * @map: Map to operate on.
+ *
+ * Blocks until any pending asynchronous I/O has completed.  Returns
+ * an error code for any failed I/O operations.
+ */
+int regmap_async_complete(struct regmap *map)
+{
+	unsigned long flags;
+	int ret;
+
+	/* Nothing to do with no async support */
+	if (!map->bus->async_write)
+		return 0;
+
+	wait_event(map->async_waitq, regmap_async_is_done(map));
+
+	spin_lock_irqsave(&map->async_lock, flags);
+	ret = map->async_ret;
+	map->async_ret = 0;
+	spin_unlock_irqrestore(&map->async_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_async_complete);
+
 /**
  * regmap_register_patch: Register and apply register updates to be applied
  *                        on device initialistion

include/linux/regmap.h

@@ -235,14 +235,21 @@ struct regmap_range_cfg {
 	unsigned int window_len;
 };
 
+struct regmap_async;
+
 typedef int (*regmap_hw_write)(void *context, const void *data,
 			       size_t count);
 typedef int (*regmap_hw_gather_write)(void *context,
 				      const void *reg, size_t reg_len,
 				      const void *val, size_t val_len);
+typedef int (*regmap_hw_async_write)(void *context,
+				     const void *reg, size_t reg_len,
+				     const void *val, size_t val_len,
+				     struct regmap_async *async);
 typedef int (*regmap_hw_read)(void *context,
 			      const void *reg_buf, size_t reg_size,
 			      void *val_buf, size_t val_size);
+typedef struct regmap_async *(*regmap_hw_async_alloc)(void);
 typedef void (*regmap_hw_free_context)(void *context);
 
 /**
@@ -255,8 +262,11 @@ typedef void (*regmap_hw_free_context)(void *context);
  * @write: Write operation.
  * @gather_write: Write operation with split register/value, return -ENOTSUPP
  *                if not implemented  on a given device.
+ * @async_write: Write operation which completes asynchronously, optional and
+ *               must serialise with respect to non-async I/O.
  * @read: Read operation.  Data is returned in the buffer used to transmit
  *         data.
+ * @async_alloc: Allocate a regmap_async() structure.
  * @read_flag_mask: Mask to be set in the top byte of the register when doing
  *                  a read.
  * @reg_format_endian_default: Default endianness for formatted register
@@ -265,13 +275,16 @@ typedef void (*regmap_hw_free_context)(void *context);
  * @val_format_endian_default: Default endianness for formatted register
  *     values. Used when the regmap_config specifies DEFAULT. If this is
  *     DEFAULT, BIG is assumed.
+ * @async_size: Size of struct used for async work.
  */
 struct regmap_bus {
 	bool fast_io;
 	regmap_hw_write write;
 	regmap_hw_gather_write gather_write;
+	regmap_hw_async_write async_write;
 	regmap_hw_read read;
 	regmap_hw_free_context free_context;
+	regmap_hw_async_alloc async_alloc;
 	u8 read_flag_mask;
 	enum regmap_endian reg_format_endian_default;
 	enum regmap_endian val_format_endian_default;
@@ -310,6 +323,8 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
 		     const void *val, size_t val_len);
 int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 			size_t val_count);
+int regmap_raw_write_async(struct regmap *map, unsigned int reg,
+			   const void *val, size_t val_len);
 int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
 int regmap_raw_read(struct regmap *map, unsigned int reg,
 		    void *val, size_t val_len);
@@ -321,6 +336,7 @@ int regmap_update_bits_check(struct regmap *map, unsigned int reg,
 			     unsigned int mask, unsigned int val,
 			     bool *change);
 int regmap_get_val_bytes(struct regmap *map);
+int regmap_async_complete(struct regmap *map);
 
 int regcache_sync(struct regmap *map);
 int regcache_sync_region(struct regmap *map, unsigned int min,
@@ -422,6 +438,13 @@ static inline int regmap_raw_write(struct regmap *map, unsigned int reg,
 	return -EINVAL;
 }
 
+static inline int regmap_raw_write_async(struct regmap *map, unsigned int reg,
+					 const void *val, size_t val_len)
+{
+	WARN_ONCE(1, "regmap API is disabled");
+	return -EINVAL;
+}
+
 static inline int regmap_bulk_write(struct regmap *map, unsigned int reg,
 				    const void *val, size_t val_count)
 {
@@ -500,6 +523,11 @@ static inline void regcache_mark_dirty(struct regmap *map)
 	WARN_ONCE(1, "regmap API is disabled");
 }
 
+static inline void regmap_async_complete(struct regmap *map)
+{
+	WARN_ONCE(1, "regmap API is disabled");
+}
+
 static inline int regmap_register_patch(struct regmap *map,
 					const struct reg_default *regs,
 					int num_regs)