[PATCH 3/4] regmap: Don't use format_val in regmap_bulk_read

From: Charles Keepax
Date: Mon Feb 12 2018 - 13:16:34 EST


A bulk read can be implemented either through regmap_raw_read, or
by reading each register individually using regmap_read. Both
regmap_read and regmap_bulk_read should return values in native
endian. In the individual case the current implementation calls
format_val to put the data into the output array, which can cause
endian issues. The regmap_read will have already converted the data
into native endian, if the hosts endian differs from the device then
format_val will switch the endian back again.

Rather than using format_val simply use the code that is called if
there is no format_val function. This code supports all cases except
24-bit but there don't appear to be any users of regmap_bulk_read for
24-bit. Additionally, it would have to be a big endian host for the
old code to actually function correctly anyway.

Fixes: 15b8d2c41fe5 ("regmap: Fix regmap_bulk_read in BE mode")
Reported-by: David Rhodes <david.rhodes@xxxxxxxxxx>
Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/base/regmap/regmap.c | 55 ++++++++++++++++++--------------------------
1 file changed, 23 insertions(+), 32 deletions(-)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 2339b98f1b6e4..8594b02aa3e67 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -2709,47 +2709,38 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
for (i = 0; i < val_count * val_bytes; i += val_bytes)
map->format.parse_inplace(val + i);
} else {
+#ifdef CONFIG_64BIT
+ u64 *u64 = val;
+#endif
+ u32 *u32 = val;
+ u16 *u16 = val;
+ u8 *u8 = val;
+
for (i = 0; i < val_count; i++) {
unsigned int ival;
+
ret = regmap_read(map, reg + regmap_get_offset(map, i),
&ival);
if (ret != 0)
return ret;

- if (map->format.format_val) {
- map->format.format_val(val + (i * val_bytes), ival, 0);
- } else {
- /* Devices providing read and write
- * operations can use the bulk I/O
- * functions if they define a val_bytes,
- * we assume that the values are native
- * endian.
- */
-#ifdef CONFIG_64BIT
- u64 *u64 = val;
-#endif
- u32 *u32 = val;
- u16 *u16 = val;
- u8 *u8 = val;
-
- switch (map->format.val_bytes) {
+ switch (map->format.val_bytes) {
#ifdef CONFIG_64BIT
- case 8:
- u64[i] = ival;
- break;
+ case 8:
+ u64[i] = ival;
+ break;
#endif
- case 4:
- u32[i] = ival;
- break;
- case 2:
- u16[i] = ival;
- break;
- case 1:
- u8[i] = ival;
- break;
- default:
- return -EINVAL;
- }
+ case 4:
+ u32[i] = ival;
+ break;
+ case 2:
+ u16[i] = ival;
+ break;
+ case 1:
+ u8[i] = ival;
+ break;
+ default:
+ return -EINVAL;
}
}
}
--
2.11.0