Simplify AUX data read by removing index arithmetic and shifting with
a helper functions that does three things:
1. Fetch data from up to 4 32-bit registers from the chip
2. Optionally fix data endianness (not needed on LE hosts)
3. Copy read data into user provided array.
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
Cc: Archit Taneja <architt@xxxxxxxxxxxxxx>
Cc: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
Cc: Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Cc: Andrey Gusakov <andrey.gusakov@xxxxxxxxxxxxxxxxxx>
Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Cc: Cory Tusar <cory.tusar@xxxxxxxx>
Cc: Chris Healy <cphealy@xxxxxxxxx>
Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/gpu/drm/bridge/tc358767.c | 40 +++++++++++++++++++++----------
1 file changed, 27 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index e197ce0fb166..da47d81e7109 100644
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -321,6 +321,29 @@ static int tc_aux_get_status(struct tc_data *tc, u8 *reply)
return 0;
}
+static int tc_aux_read_data(struct tc_data *tc, void *data, size_t size)
+{
+ u32 auxrdata[DP_AUX_MAX_PAYLOAD_BYTES / sizeof(u32)];
+ int ret, i, count = DIV_ROUND_UP(size, sizeof(u32));
+
+ ret = regmap_bulk_read(tc->regmap, DP0_AUXRDATA(0), auxrdata, count);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < count; i++) {
+ /*
+ * Our regmap is configured as LE for register data,
+ * so we need undo any byte swapping that might have
+ * happened to preserve original byte order.
+ */
+ le32_to_cpus(&auxrdata[i]);
+ }
+
+ memcpy(data, auxrdata, size);
+
+ return size;
+}
+
static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
struct drm_dp_aux_msg *msg)
{
@@ -379,19 +402,10 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
if (ret)
return ret;
- if (request == DP_AUX_I2C_READ || request == DP_AUX_NATIVE_READ) {
- /* Read data */
- while (i < size) {
- if ((i % 4) == 0) {
- ret = regmap_read(tc->regmap,
- DP0_AUXRDATA(i >> 2), &tmp);
- if (ret)
- return ret;
- }
- buf[i] = tmp & 0xff;
- tmp = tmp >> 8;
- i++;
- }
+ switch (request) {
+ case DP_AUX_NATIVE_READ:
+ case DP_AUX_I2C_READ:
+ return tc_aux_read_data(tc, msg->buffer, size);
}
return size;
--
2.21.0
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