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drm/bridge: tc358767: Add support for address-only I2C transfers

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Transfer size of zero means a request to do an address-only
transfer. Since the HW support this, we probably shouldn't be just
ignoring such requests. While at it allow DP_AUX_I2C_MOT flag to pass
through, since it is supported by the HW as well.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Andrey Gusakov <andrey.gusakov@cogentembedded.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Cory Tusar <cory.tusar@zii.aero>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190619052716.16831-16-andrew.smirnov@gmail.com
This commit is contained in:
Andrey Smirnov 2019-06-18 22:27:16 -07:00 committed by Andrzej Hajda
parent 32d3621996
commit fdb29b7380
1 changed files with 31 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

42
drivers/gpu/drm/bridge/tc358767.c
View file

@ -136,6 +136,8 @@
/* AUX channel */
#define DP0_AUXCFG0 0x0660
#define DP0_AUXCFG0_BSIZE GENMASK(11, 8)
#define DP0_AUXCFG0_ADDR_ONLY BIT(4)
#define DP0_AUXCFG1 0x0664
#define AUX_RX_FILTER_EN BIT(16)
@ -317,6 +319,18 @@ static int tc_aux_read_data(struct tc_data *tc, void *data, size_t size)
return size;
}
static u32 tc_auxcfg0(struct drm_dp_aux_msg *msg, size_t size)
{
u32 auxcfg0 = msg->request;
if (size)
auxcfg0 |= FIELD_PREP(DP0_AUXCFG0_BSIZE, size - 1);
else
auxcfg0 |= DP0_AUXCFG0_ADDR_ONLY;
return auxcfg0;
}
static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
struct drm_dp_aux_msg *msg)
{
@ -326,9 +340,6 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
u32 auxstatus;
int ret;
if (size == 0)
return 0;
ret = tc_aux_wait_busy(tc);
if (ret)
return ret;
@ -339,9 +350,11 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
break;
case DP_AUX_NATIVE_WRITE:
case DP_AUX_I2C_WRITE:
ret = tc_aux_write_data(tc, msg->buffer, size);
if (ret < 0)
return ret;
if (size) {
ret = tc_aux_write_data(tc, msg->buffer, size);
if (ret < 0)
return ret;
}
break;
default:
return -EINVAL;
@ -352,8 +365,7 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
if (ret)
return ret;
/* Start transfer */
ret = regmap_write(tc->regmap, DP0_AUXCFG0,
((size - 1) << 8) | request);
ret = regmap_write(tc->regmap, DP0_AUXCFG0, tc_auxcfg0(msg, size));
if (ret)
return ret;
@ -367,14 +379,22 @@ static ssize_t tc_aux_transfer(struct drm_dp_aux *aux,
if (auxstatus & AUX_TIMEOUT)
return -ETIMEDOUT;
size = FIELD_GET(AUX_BYTES, auxstatus);
/*
* For some reason address-only DP_AUX_I2C_WRITE (MOT), still
* reports 1 byte transferred in its status. To deal we that
* we ignore aux_bytes field if we know that this was an
* address-only transfer
*/
if (size)
size = FIELD_GET(AUX_BYTES, auxstatus);
msg->reply = FIELD_GET(AUX_STATUS, auxstatus);
switch (request) {
case DP_AUX_NATIVE_READ:
case DP_AUX_I2C_READ:
return tc_aux_read_data(tc, msg->buffer, size);
if (size)
return tc_aux_read_data(tc, msg->buffer, size);
break;
}
return size;