From 3245d460a1eb55b5c3ca31dde7b5c5ac71546edf Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 2 Feb 2016 10:16:51 -0200 Subject: [PATCH] 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: Mark Brown [maciej: Use cache_bypass around read and skipping of unreadable regs] Signed-off-by: Maciej S. Szmigiero Signed-off-by: Fabio Estevam Tested-by: Fabio Estevam Signed-off-by: Mark Brown --- drivers/base/regmap/regcache.c | 41 +++++++++++++++++++++++++--------- 1 file changed, 30 insertions(+), 11 deletions(-) diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c index 348be3a35410..cccceb599b02 100644 --- a/drivers/base/regmap/regcache.c +++ b/drivers/base/regmap/regcache.c @@ -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; - - map->reg_defaults_raw = tmp_buf; - map->cache_free = 1; + 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; - val = regcache_get_val(map, map->reg_defaults_raw, i); - map->reg_defaults[j].reg = i * map->reg_stride; + + if (regmap_volatile(map, reg)) + continue; + + if (map->reg_defaults_raw) { + val = regcache_get_val(map, map->reg_defaults_raw, i); + } 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); -- 2.20.1