regmap: Add asynchronous I/O support

Some use cases like firmware download can transfer a lot of data in quick
succession. With high speed buses these use cases can benefit from having
multiple transfers scheduled at once since this allows the bus to minimise
the delay between transfers.

Support this by adding regmap_raw_write_async(), allowing raw transfers to
be scheduled, and regmap_async_complete() to wait for them to finish.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 51f05740564..20251864177 100644
--- a/drivers/base/regmap/internal.h
+++ b/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;
@@ -178,6 +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;