regmap: Add support for register indirect addressing.

Devices with register paging or indirectly accessed registers can configure
register mapping to map those on virtual address range. During access to
virtually mapped register range, indirect addressing is processed
automatically, in following steps:
  1. selector for page or indirect register is updated (when needed);
  2. register in data window is accessed.

Configuration should provide minimum and maximum register for virtual range,
details of selector field for page selection, minimum and maximum register of
data window for indirect access.

Virtual range registers are managed by cache as well as direct access
registers. In order to make indirect access more efficient, selector register
should be declared as non-volatile, if possible.

struct regmap_config is extended with the following:
struct regmap_range_cfg	*ranges;
unsigned int		n_ranges;

[Also reordered debugfs init to later on since the cleanup code was
conflicting with the new cleanup code for ranges anyway -- broonie]

Signed-off-by: Krystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index b986b86..80f9ab9 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -95,6 +95,9 @@ struct regmap {
 
 	/* if set, converts bulk rw to single rw */
 	bool use_single_rw;
+
+	struct rb_root range_tree;
+	void *selector_work_buf;	/* Scratch buffer used for selector */
 };
 
 struct regcache_ops {
@@ -115,6 +118,20 @@ bool regmap_precious(struct regmap *map, unsigned int reg);
 int _regmap_write(struct regmap *map, unsigned int reg,
 		  unsigned int val);
 
+struct regmap_range_node {
+	struct rb_node node;
+
+	unsigned int range_min;
+	unsigned int range_max;
+
+	unsigned int selector_reg;
+	unsigned int selector_mask;
+	int selector_shift;
+
+	unsigned int window_start;
+	unsigned int window_len;
+};
+
 #ifdef CONFIG_DEBUG_FS
 extern void regmap_debugfs_initcall(void);
 extern void regmap_debugfs_init(struct regmap *map, const char *name);