From 04dc91ce2cca5927159c689aa1f47663f8c51530 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Mon, 13 Jul 2015 12:26:44 +0200 Subject: [PATCH] regmap: Add better support for devices without readback support Currently regmap requires that a reg_read callback is supplied, otherwise a warning is emitted each time regmap_read() is called. This means a device or bus without readback support needs to supply dummy reg_read callback. Apart from that regmap_read() will still work fine if a cache is used. Remove the warning and let regmap_readable() return false if not reg_read callback is supplied. This means a device no longer has to supply a dummy callback if it does not support readback and it also doesn't have to have a readable_reg callback that always returns false since this is now implicit. Signed-off-by: Lars-Peter Clausen Signed-off-by: Mark Brown --- drivers/base/regmap/regmap.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 7111d04f2621..8894b992043e 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -93,6 +93,9 @@ bool regmap_writeable(struct regmap *map, unsigned int reg) bool regmap_readable(struct regmap *map, unsigned int reg) { + if (!map->reg_read) + return false; + if (map->max_register && reg > map->max_register) return false; @@ -2097,8 +2100,6 @@ static int _regmap_read(struct regmap *map, unsigned int reg, int ret; void *context = _regmap_map_get_context(map); - WARN_ON(!map->reg_read); - if (!map->cache_bypass) { ret = regcache_read(map, reg, val); if (ret == 0) -- 2.20.1