3 files changed, 34 insertions, 14 deletions

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index a6e4689000af..c73036744468 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -322,6 +322,7 @@ static inline unsigned int regcache_get_index_by_order(const struct regmap *map,
 }
 
 struct regmap_ram_data {
+	unsigned int base_reg;
 	unsigned int *vals;  /* Allocatd by caller */
 	bool *read;
 	bool *written;
diff --git a/drivers/base/regmap/regmap-ram.c b/drivers/base/regmap/regmap-ram.c
index c7356b0d8c83..a666bfb4d667 100644
--- a/drivers/base/regmap/regmap-ram.c
+++ b/drivers/base/regmap/regmap-ram.c
@@ -20,8 +20,11 @@ static int regmap_ram_write(void *context, unsigned int reg, unsigned int val)
 {
 	struct regmap_ram_data *data = context;
 
-	data->vals[reg] = val;
-	data->written[reg] = true;
+	if (reg < data->base_reg)
+		return -EINVAL;
+
+	data->vals[reg - data->base_reg] = val;
+	data->written[reg - data->base_reg] = true;
 
 	return 0;
 }
@@ -30,8 +33,11 @@ static int regmap_ram_read(void *context, unsigned int reg, unsigned int *val)
 {
 	struct regmap_ram_data *data = context;
 
-	*val = data->vals[reg];
-	data->read[reg] = true;
+	if (reg < data->base_reg)
+		return -EINVAL;
+
+	*val = data->vals[reg - data->base_reg];
+	data->read[reg - data->base_reg] = true;
 
 	return 0;
 }
@@ -60,17 +66,25 @@ struct regmap *__regmap_init_ram(struct device *dev,
 				 const char *lock_name)
 {
 	struct regmap *map;
+	unsigned int num_regs;
 
 	if (!config->max_register) {
 		pr_crit("No max_register specified for RAM regmap\n");
 		return ERR_PTR(-EINVAL);
 	}
 
-	data->read = kzalloc_objs(bool, config->max_register + 1);
+	if (data->base_reg > config->max_register) {
+		pr_crit("base_reg above max_register for RAM regmap\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	num_regs = config->max_register - data->base_reg + 1;
+
+	data->read = kzalloc_objs(bool, num_regs);
 	if (!data->read)
 		return ERR_PTR(-ENOMEM);
 
-	data->written = kzalloc_objs(bool, config->max_register + 1);
+	data->written = kzalloc_objs(bool, num_regs);
 	if (!data->written) {
 		kfree(data->read);
 		return ERR_PTR(-ENOMEM);
diff --git a/drivers/base/regmap/regmap-raw-ram.c b/drivers/base/regmap/regmap-raw-ram.c
index 60d6e95cdd1b..c63c464549f9 100644
--- a/drivers/base/regmap/regmap-raw-ram.c
+++ b/drivers/base/regmap/regmap-raw-ram.c
@@ -16,14 +16,17 @@
 
 #include "internal.h"
 
-static unsigned int decode_reg(enum regmap_endian endian, const void *reg)
+static unsigned int decode_reg(struct regmap_ram_data *data, const void *reg)
 {
 	const u16 *r = reg;
+	unsigned int decode;
 
-	if (endian == REGMAP_ENDIAN_BIG)
-		return be16_to_cpu(*r);
+	if (data->reg_endian == REGMAP_ENDIAN_BIG)
+		decode = be16_to_cpu(*r);
 	else
-		return le16_to_cpu(*r);
+		decode = le16_to_cpu(*r);
+
+	return decode - data->base_reg;
 }
 
 static int regmap_raw_ram_gather_write(void *context,
@@ -40,7 +43,7 @@ static int regmap_raw_ram_gather_write(void *context,
 	if (val_len % 2)
 		return -EINVAL;
 
-	r = decode_reg(data->reg_endian, reg);
+	r = decode_reg(data, reg);
 	if (data->noinc_reg && data->noinc_reg(data, r)) {
 		memcpy(&our_buf[r], val + val_len - 2, 2);
 		data->written[r] = true;
@@ -74,7 +77,7 @@ static int regmap_raw_ram_read(void *context,
 	if (val_len % 2)
 		return -EINVAL;
 
-	r = decode_reg(data->reg_endian, reg);
+	r = decode_reg(data, reg);
 	if (data->noinc_reg && data->noinc_reg(data, r)) {
 		for (i = 0; i < val_len; i += 2)
 			memcpy(val + i, &our_buf[r], 2);
@@ -114,6 +117,7 @@ struct regmap *__regmap_init_raw_ram(struct device *dev,
 				     const char *lock_name)
 {
 	struct regmap *map;
+	unsigned int regs;
 
 	if (config->reg_bits != 16)
 		return ERR_PTR(-EINVAL);
@@ -123,11 +127,12 @@ struct regmap *__regmap_init_raw_ram(struct device *dev,
 		return ERR_PTR(-EINVAL);
 	}
 
-	data->read = kzalloc_objs(bool, config->max_register + 1);
+	regs = config->max_register - data->base_reg + 1;
+	data->read = kzalloc_objs(bool, regs);
 	if (!data->read)
 		return ERR_PTR(-ENOMEM);
 
-	data->written = kzalloc_objs(bool, config->max_register + 1);
+	data->written = kzalloc_objs(bool, regs);
 	if (!data->written)
 		return ERR_PTR(-ENOMEM);