Subject: drm/i2c: tda998x: Set CEC I2C address from TDA I2C address

From: [email-masked] (Andrew Jackson)
Date: Wed, 2 Jul 2014 11:45:56 +0100

On 07/02/14 11:25, Russell King - ARM Linux wrote:
> You missed me as the maintainer of the driver:

Sorry, an over-sight on my part.

> NXP TDA998X DRM DRIVER
> M:      Russell King <[email-masked]>
> S:      Supported
> F:      drivers/gpu/drm/i2c/tda998x_drv.c
> F:      include/drm/i2c/tda998x.h
>
> On Wed, Jul 02, 2014 at 10:33:44AM +0100, Andrew Jackson wrote:
>> @@ -1274,9 +1275,9 @@ tda998x_encoder_init(struct i2c_client *client,
>>
>>         priv->current_page = 0xff;
>>         priv->hdmi = client;
>> -       priv->cec = i2c_new_dummy(client->adapter, 0x34);
>> -       if (!priv->cec)
>> -               priv->cec = i2c_new_dummy(client->adapter, 0x35);
>> +       /* CEC I2C address bound to TDA998x I2C addr by configuration pins */
>> +       cec_addr = 0x34 + (client->addr & 3);
>> +       priv->cec = i2c_new_dummy(client->adapter, cec_addr);
>
> We discussed the issue of the I2C CEC address when the DT binding first
> came up...
>
> Do we know for certain that the above is always true for all the devices
> that this driver supports?

I know that it is true for the following:

        * TDA9989 (Both lower LSBs are zero)
        * TDA19988 (LSBs are set from configuration pins)
        * TDA19989 (Both lower LSBs are zero)

I don't know about the N2 variants of the various devices.

I have tested the patch on board containing two TDA19988s.

   Andrew

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