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Commit 3245d460 authored by Mark Brown's avatar Mark Brown
Browse files

regmap: cache: Fall back to register by register read for cache defaults 



If we are unable to read the cache defaults for a regmap then fall back
on attempting to read them word by word. This is going to be painfully
slow for large regmaps but might be adequate for smaller ones.

Signed-off-by: default avatarMark Brown <broonie@kernel.org>
[maciej: Use cache_bypass around read and skipping of unreadable regs]
Signed-off-by: default avatarMaciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: default avatarFabio Estevam <fabio.estevam@nxp.com>
Tested-by: default avatarFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent bb2bb45d

drivers/base/regmap/regcache.c

+30 −11
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ static int regcache_hw_init(struct regmap *map) 
	int i, j;

	int ret;

	int count;

	unsigned int val;

	unsigned int reg, val;

	void *tmp_buf;



	if (!map->num_reg_defaults_raw)
@@ -67,27 +67,46 @@ static int regcache_hw_init(struct regmap *map) 
		ret = regmap_raw_read(map, 0, tmp_buf,

				      map->num_reg_defaults_raw);

		map->cache_bypass = cache_bypass;

		if (ret < 0)

			goto err_cache_free;



		if (ret == 0) {

			map->reg_defaults_raw = tmp_buf;

			map->cache_free = 1;

		} else {

			kfree(tmp_buf);

		}

	}



	/* fill the reg_defaults */

	for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) {

		if (regmap_volatile(map, i * map->reg_stride))

		reg = i * map->reg_stride;



		if (!regmap_readable(map, reg))

			continue;



		if (regmap_volatile(map, reg))

			continue;



		if (map->reg_defaults_raw) {

			val = regcache_get_val(map, map->reg_defaults_raw, i);

		map->reg_defaults[j].reg = i * map->reg_stride;

		} else {

			bool cache_bypass = map->cache_bypass;



			map->cache_bypass = true;

			ret = regmap_read(map, reg, &val);

			map->cache_bypass = cache_bypass;

			if (ret != 0) {

				dev_err(map->dev, "Failed to read %d: %d\n",

					reg, ret);

				goto err_free;

			}

		}



		map->reg_defaults[j].reg = reg;

		map->reg_defaults[j].def = val;

		j++;

	}



	return 0;



err_cache_free:

	kfree(tmp_buf);

err_free:

	kfree(map->reg_defaults);