Before adding support to define bulk read/write callbacks in regmap_config
by the commit d77e745613 ("regmap: Add bulk read/write callbacks into
regmap_config"), the regmap_noinc_read() function returned an errno early
a map->bus->read callback wasn't set.
But that commit dropped the check and now a call to _regmap_raw_read() is
attempted even when bulk read operations are not supported. That function
checks for map->read anyways but there's no point to continue if the read
can't succeed.
Also is a fragile assumption to make so is better to make it fail earlier.
Fixes: d77e745613 ("regmap: Add bulk read/write callbacks into regmap_config")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20220616073435.1988219-3-javierm@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>
c42e99a3f9