On Mon, Sep 16, 2019 at 12:36:19PM +0200, Enric Balletbo i Serra wrote:

Hi Andrzej and Brian

On 16/9/19 12:02, Andrzej Hajda wrote:

quoted

On 15.08.2019 02:48, Brian Masney wrote:

quoted

When attempting to configure this driver on a Nexus 5 phone (msm8974),
setting up the dummy i2c bus for TX_P0 would fail due to an -EBUSY
error. The downstream MSM kernel sources [1] shows that the proper value
for TX_P0 is 0x78, not 0x70, so correct the value to allow device
probing to succeed.

[1] https://github.com/AICP/kernel_lge_hammerhead/blob/n7.1/drivers/video/slimport/slimport_tx_reg.h

Signed-off-by: Brian Masney <redacted>
---
 drivers/gpu/drm/bridge/analogix-anx78xx.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/analogix-anx78xx.h b/drivers/gpu/drm/bridge/analogix-anx78xx.h
index 25e063bcecbc..bc511fc605c9 100644
--- a/drivers/gpu/drm/bridge/analogix-anx78xx.h
+++ b/drivers/gpu/drm/bridge/analogix-anx78xx.h

@@ -6,7 +6,7 @@
 #ifndef __ANX78xx_H
 #define __ANX78xx_H
 
-#define TX_P0				0x70
+#define TX_P0				0x78

This bothers me little. There are no upstream users, grepping android
sources suggests that both values can be used [1][2]  (grep for "#define
TX_P0"), moreover there is code suggesting both values can be valid [3].

Could you verify datasheet which i2c slave addresses are valid for this
chip, if both I guess this patch should be reworked.

On my case the valid i2c slave address is 0x70 (from datasheet, very sorry I
can't share it) and the bridge used is an ANX7814, it could be that ANX7808 or
ANX7812 have different slave addresses?

I haven't been able to find any of the datasheets for these devices
online. Product briefs are online (such as 
https://www.analogix.com/en/system/files/ANX7808_product_brief.pdf), but
they don't provide this type of information.

Brian

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