lkml.org 
[lkml]   [2019]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 10/15] drm/bridge: tc358767: Add support for address-only I2C transfers
Date
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>
Cc: Archit Taneja <architt@codeaurora.org>
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: Chris Healy <cphealy@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
---
drivers/gpu/drm/bridge/tc358767.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
index 7e4607c6907f..768f01cc2a30 100644
--- a/drivers/gpu/drm/bridge/tc358767.c
+++ b/drivers/gpu/drm/bridge/tc358767.c
@@ -137,6 +137,8 @@

/* 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)

@@ -331,6 +333,18 @@ 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)
{
@@ -340,9 +354,6 @@ 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, 100);
if (ret)
return ret;
@@ -366,8 +377,7 @@ 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;

@@ -381,8 +391,14 @@ 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) {
--
2.20.1
\
 
 \ /
  Last update: 2019-03-22 04:30    [W:0.187 / U:10.644 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site