Hi Simon,
On 10/08/18 13:01, Simon Horman wrote:
> On Tue, Aug 07, 2018 at 04:59:33PM +0100, Kieran Bingham wrote:
>> Ensure that the ADV748x device addresses do not conflict, and group them
>> together (visually in i2cdetect)
>
> Hi Kieran,
>
> could you help me out with some pointers on how to correlate this
> with the HW documentation?
Not easily :) - Except for the 'main' address (0x70), these are not
addresses documented by the datasheet. <by the very nature of the
activity>. The driver supports the DT providing the slave pages to
allocate. One day the I2C framework might allow us to 'request' an
unused page :D
I performed a scan on the Salvator-X, (i2cdetect -r -y 4) and identified
a region of unused I2C address space to allocate the 12 pages so that
they did not conflict.
In particular, the address <0x30> which is the default for the CBUS page
conflicts with the default address of the OV10635 used by the GMSL
cameras on the same bus, and so I needed to move that one.
To make the effects clear, (and the i2cdetect reporting more obvious) I
chose to reassign all of the movable pages so that it is clear they are
from the same device.
Rather annoyingly it's difficult to map a slave page back to it's driver
due to the fact that it gets registered as a 'dummy' driver, so keeping
the related addresses together is quite valuable.
As soon as I get some free cycles, I plan to look at being able to map
extra driver information to dummy I2C registrations to make it easier to
identify who owns the address :)
--
Regards
Kieran
>>
>> Signed-off-by: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>
>> ---
>> arch/arm64/boot/dts/renesas/salvator-common.dtsi | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/boot/dts/renesas/salvator-common.dtsi b/arch/arm64/boot/dts/renesas/salvator-common.dtsi
>> index 5cfb9b99de89..2eba743c5c3f 100644
>> --- a/arch/arm64/boot/dts/renesas/salvator-common.dtsi
>> +++ b/arch/arm64/boot/dts/renesas/salvator-common.dtsi
>> @@ -414,7 +414,10 @@
>>
>> video-receiver@70 {
>> compatible = "adi,adv7482";
>> - reg = <0x70>;
>> + reg = <0x70 0x71 0x72 0x73 0x74 0x75
>> + 0x60 0x61 0x62 0x63 0x64 0x65>;
>> + reg-names = "main", "dpll", "cp", "hdmi", "edid", "repeater",
>> + "infoframe", "cbus", "cec", "sdp", "txa", "txb" ;
>>
>> #address-cells = <1>;
>> #size-cells = <0>;
>> --
>> 2.17.1
>>
--
Regards
--
Kieran
