1 files changed, 109 insertions, 18 deletions

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index b77f1c6abdad..e48cb8562e68 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -579,6 +579,10 @@ struct regmap *regmap_init(struct device *dev,
 	map->use_single_read = config->use_single_rw || !bus || !bus->read;
 	map->use_single_write = config->use_single_rw || !bus || !bus->write;
 	map->can_multi_write = config->can_multi_write && bus && bus->write;
+	if (bus) {
+		map->max_raw_read = bus->max_raw_read;
+		map->max_raw_write = bus->max_raw_write;
+	}
 	map->dev = dev;
 	map->bus = bus;
 	map->bus_context = bus_context;
@@ -1386,10 +1390,33 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg,
  */
 bool regmap_can_raw_write(struct regmap *map)
 {
-	return map->bus && map->format.format_val && map->format.format_reg;
+	return map->bus && map->bus->write && map->format.format_val &&
+		map->format.format_reg;
 }
 EXPORT_SYMBOL_GPL(regmap_can_raw_write);
 
+/**
+ * regmap_get_raw_read_max - Get the maximum size we can read
+ *
+ * @map: Map to check.
+ */
+size_t regmap_get_raw_read_max(struct regmap *map)
+{
+	return map->max_raw_read;
+}
+EXPORT_SYMBOL_GPL(regmap_get_raw_read_max);
+
+/**
+ * regmap_get_raw_write_max - Get the maximum size we can read
+ *
+ * @map: Map to check.
+ */
+size_t regmap_get_raw_write_max(struct regmap *map)
+{
+	return map->max_raw_write;
+}
+EXPORT_SYMBOL_GPL(regmap_get_raw_write_max);
+
 static int _regmap_bus_formatted_write(void *context, unsigned int reg,
 				       unsigned int val)
 {
@@ -1559,6 +1586,8 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
 		return -EINVAL;
 	if (val_len % map->format.val_bytes)
 		return -EINVAL;
+	if (map->max_raw_write && map->max_raw_write > val_len)
+		return -E2BIG;
 
 	map->lock(map->lock_arg);
 
@@ -1673,6 +1702,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 {
 	int ret = 0, i;
 	size_t val_bytes = map->format.val_bytes;
+	size_t total_size = val_bytes * val_count;
 
 	if (map->bus && !map->format.parse_inplace)
 		return -EINVAL;
@@ -1721,16 +1751,37 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 		}
 out:
 		map->unlock(map->lock_arg);
-	} else if (map->use_single_write) {
+	} else if (map->use_single_write ||
+		   (map->max_raw_write && map->max_raw_write < total_size)) {
+		int chunk_stride = map->reg_stride;
+		size_t chunk_size = val_bytes;
+		size_t chunk_count = val_count;
+
+		if (!map->use_single_write) {
+			chunk_size = map->max_raw_write;
+			if (chunk_size % val_bytes)
+				chunk_size -= chunk_size % val_bytes;
+			chunk_count = total_size / chunk_size;
+			chunk_stride *= chunk_size / val_bytes;
+		}
+
 		map->lock(map->lock_arg);
-		for (i = 0; i < val_count; i++) {
+		/* Write as many bytes as possible with chunk_size */
+		for (i = 0; i < chunk_count; i++) {
 			ret = _regmap_raw_write(map,
-						reg + (i * map->reg_stride),
-						val + (i * val_bytes),
-						val_bytes);
+						reg + (i * chunk_stride),
+						val + (i * chunk_size),
+						chunk_size);
 			if (ret)
 				break;
 		}
+
+		/* Write remaining bytes */
+		if (!ret && chunk_size * i < total_size) {
+			ret = _regmap_raw_write(map, reg + (i * chunk_stride),
+						val + (i * chunk_size),
+						total_size - i * chunk_size);
+		}
 		map->unlock(map->lock_arg);
 	} else {
 		void *wval;
@@ -1761,7 +1812,7 @@ EXPORT_SYMBOL_GPL(regmap_bulk_write);
  *
  * the (register,newvalue) pairs in regs have not been formatted, but
  * they are all in the same page and have been changed to being page
- * relative. The page register has been written if that was neccessary.
+ * relative. The page register has been written if that was necessary.
  */
 static int _regmap_raw_multi_reg_write(struct regmap *map,
 				       const struct reg_default *regs,
@@ -2071,7 +2122,7 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 
 	/*
 	 * Some buses or devices flag reads by setting the high bits in the
-	 * register addresss; since it's always the high bits for all
+	 * register address; since it's always the high bits for all
 	 * current formats we can do this here rather than in
 	 * formatting.  This may break if we get interesting formats.
 	 */
@@ -2205,6 +2256,15 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 
 	if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
 	    map->cache_type == REGCACHE_NONE) {
+		if (!map->bus->read) {
+			ret = -ENOTSUPP;
+			goto out;
+		}
+		if (map->max_raw_read && map->max_raw_read < val_len) {
+			ret = -E2BIG;
+			goto out;
+		}
+
 		/* Physical block read if there's no cache involved */
 		ret = _regmap_raw_read(map, reg, val, val_len);
 
@@ -2313,20 +2373,51 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 		 * Some devices does not support bulk read, for
 		 * them we have a series of single read operations.
 		 */
-		if (map->use_single_read) {
-			for (i = 0; i < val_count; i++) {
-				ret = regmap_raw_read(map,
-						reg + (i * map->reg_stride),
-						val + (i * val_bytes),
-						val_bytes);
-				if (ret != 0)
-					return ret;
-			}
-		} else {
+		size_t total_size = val_bytes * val_count;
+
+		if (!map->use_single_read &&
+		    (!map->max_raw_read || map->max_raw_read > total_size)) {
 			ret = regmap_raw_read(map, reg, val,
 					      val_bytes * val_count);
 			if (ret != 0)
 				return ret;
+		} else {
+			/*
+			 * Some devices do not support bulk read or do not
+			 * support large bulk reads, for them we have a series
+			 * of read operations.
+			 */
+			int chunk_stride = map->reg_stride;
+			size_t chunk_size = val_bytes;
+			size_t chunk_count = val_count;
+
+			if (!map->use_single_read) {
+				chunk_size = map->max_raw_read;
+				if (chunk_size % val_bytes)
+					chunk_size -= chunk_size % val_bytes;
+				chunk_count = total_size / chunk_size;
+				chunk_stride *= chunk_size / val_bytes;
+			}
+
+			/* Read bytes that fit into a multiple of chunk_size */
+			for (i = 0; i < chunk_count; i++) {
+				ret = regmap_raw_read(map,
+						      reg + (i * chunk_stride),
+						      val + (i * chunk_size),
+						      chunk_size);
+				if (ret != 0)
+					return ret;
+			}
+
+			/* Read remaining bytes */
+			if (chunk_size * i < total_size) {
+				ret = regmap_raw_read(map,
+						      reg + (i * chunk_stride),
+						      val + (i * chunk_size),
+						      total_size - i * chunk_size);
+				if (ret != 0)
+					return ret;
+			}
 		}
 
 		for (i = 0; i < val_count * val_bytes; i += val_bytes)