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authorChen-Yu Tsai <wens@csie.org>2019-04-13 11:32:52 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-25 19:43:11 +0200
commit273a474ee843fe6f77c3fef365306018bac9c96d (patch)
tree56eb6af8aaa3f9de711f073d060349737644df08 /drivers/nvmem
parent7fa5ad23dbb02fc9832ef303adbca06f425250d5 (diff)
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nvmem: sunxi_sid: Read out data in native format
Originally the SID e-fuses were thought to be in big-endian format. Later sources show that they are in fact native or little-endian. The most compelling evidence is the thermal sensor calibration data, which is a set of one to three 16-bit values. In native-endian they are in 16-bit cells with increasing offsets, whereas with big-endian they are in the wrong order, and a gap with no data will show if there are one or three cells. Switch to a native endian representation for the nvmem device. For the H3, the register read-out method was already returning data in native endian. This only affects the other SoCs. Signed-off-by: Chen-Yu Tsai <wens@csie.org> Acked-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/nvmem')
-rw-r--r--drivers/nvmem/sunxi_sid.c23
1 files changed, 1 insertions, 22 deletions
diff --git a/drivers/nvmem/sunxi_sid.c b/drivers/nvmem/sunxi_sid.c
index 75c1f48cb3d0..14c114620ed6 100644
--- a/drivers/nvmem/sunxi_sid.c
+++ b/drivers/nvmem/sunxi_sid.c
@@ -46,33 +46,12 @@ struct sunxi_sid {
u32 value_offset;
};
-/* We read the entire key, due to a 32 bit read alignment requirement. Since we
- * want to return the requested byte, this results in somewhat slower code and
- * uses 4 times more reads as needed but keeps code simpler. Since the SID is
- * only very rarely probed, this is not really an issue.
- */
-static u8 sunxi_sid_read_byte(const struct sunxi_sid *sid,
- const unsigned int offset)
-{
- u32 sid_key;
-
- sid_key = ioread32be(sid->base + round_down(offset, 4));
- sid_key >>= (offset % 4) * 8;
-
- return sid_key; /* Only return the last byte */
-}
-
static int sunxi_sid_read(void *context, unsigned int offset,
void *val, size_t bytes)
{
struct sunxi_sid *sid = context;
- u8 *buf = val;
-
- /* Offset the read operation to the real position of SID */
- offset += sid->value_offset;
- while (bytes--)
- *buf++ = sunxi_sid_read_byte(sid, offset++);
+ memcpy_fromio(val, sid->base + sid->value_offset + offset, bytes);
return 0;
}