Re: [PATCH 01/12] drm/amdgpu: add amd_gnb_bus support

[Mark Brown <broonie@kernel.org>]

[-- Attachment #1.1: Type: text/plain, Size: 1033 bytes --]

On Thu, Aug 06, 2015 at 10:25:02AM -0400, Alex Deucher wrote:
> From: Chunming Zhou <david1.zhou@amd.com>
> 
> This is used by the incoming ACP driver.  The DMA
> engine for the i2s audio codec is part of the GPU.
> 
> This exposes an amd gnb bus for the i2s codec to
> hang off of.

Could you be more specific about what an "amd gnd bus" is please?

> +enum amd_gnb_bus_ip {
> +	AMD_GNB_IP_ACP_DMA,
> +	AMD_GNB_IP_ACP_I2S,
> +	AMD_GNB_IP_ACP_PCM,
> +	AMD_GNB_IP_ISP,
> +	AMD_GNB_IP_NUM
> +};
> +
> +struct amd_gnb_bus_dev {
> +	struct device dev; /* generic device interface */
> +	enum amd_gnb_bus_ip ip;
> +	/* private data can be acp_handle/isp_handle etc.*/
> +	void *private_data;
> +};

Looking at the code I'm not seeing too much bus specific except for the
above which looks like the sort of device we usually represent as a MFD
(with the MFD providing resource distribution and arbitration between
various component devices which fit into the subsystem).  Why code a new
bus for this device?

[-- Attachment #1.2: Digital signature --]
[-- Type: application/pgp-signature, Size: 473 bytes --]

[-- Attachment #2: Type: text/plain, Size: 0 bytes --]