Re: [PATCH v2 7/7] OMAPDSS: HDMI: Create platform device for audio support

From: Tomi Valkeinen <tomi.valkeinen@ti.com>
To: Ricardo Neri <ricardo.neri@ti.com>
Cc: peter.ujfalusi@ti.com, s-guiriec@ti.com, b-cousson@ti.com,
	linux-omap@vger.kernel.org
Subject: Re: [PATCH v2 7/7] OMAPDSS: HDMI: Create platform device for audio support
Date: Mon, 5 Nov 2012 10:46:15 +0200	[thread overview]
Message-ID: <50977CD7.7070609@ti.com> (raw)
In-Reply-To: <1351902708-866-8-git-send-email-ricardo.neri@ti.com>

[-- Attachment #1: Type: text/plain, Size: 3108 bytes --]

On 2012-11-03 02:31, Ricardo Neri wrote:
> Creating the accessory devices, such as audio, from the HDMI driver
> allows to regard HDMI as a single entity with audio an display
> functionality. This intends to follow the design of drivers such
> as MFD, in which a single entity handles the creation of the accessory
> devices. Such devices are then used by domain-specific drivers; audio in
> this case.
> 
> Also, this is in line with the DT implementation of HDMI, in which we will
> have a single node to describe this feature of the OMAP SoC.
> 
> Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
> ---
>  drivers/video/omap2/dss/hdmi.c |   62 ++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 62 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/video/omap2/dss/hdmi.c b/drivers/video/omap2/dss/hdmi.c
> index 4adf830..d6ce4c6 100644
> --- a/drivers/video/omap2/dss/hdmi.c
> +++ b/drivers/video/omap2/dss/hdmi.c
> @@ -60,6 +60,9 @@
>  static struct {
>  	struct mutex lock;
>  	struct platform_device *pdev;
> +#if defined(CONFIG_OMAP4_DSS_HDMI_AUDIO)
> +	struct platform_device *audio_pdev;
> +#endif
>  
>  	struct hdmi_ip_data ip_data;
>  
> @@ -766,6 +769,54 @@ static void hdmi_put_clocks(void)
>  }
>  
>  #if defined(CONFIG_OMAP4_DSS_HDMI_AUDIO)
> +static int hdmi_probe_audio(struct platform_device *pdev)
> +{
> +	struct resource *res;
> +	u32 port_offset, port_size;
> +	struct resource aud_res[2] = {
> +		DEFINE_RES_MEM(-1, -1),
> +		DEFINE_RES_DMA(-1),
> +	};
> +
> +	hdmi.audio_pdev = ERR_PTR(-EINVAL);

I don't like this. I think ERR_PTR stuff should be used only for return
values, not when storing pointers. I think it's much more natural and
less error prone to do if (hdmi.audio_pdev == NULL) than if
(IS_ERR(hdmi.audio_pdev)).

So store the return value from platform_dev_register first to a local
variable, check IS_ERR for that, and only then store it to hdmi.audio_pdev.

> +	res = platform_get_resource(hdmi.pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		DSSERR("can't get IORESOURCE_MEM HDMI\n");
> +		return -EINVAL;
> +	}
> +
> +	/*
> +	 * Pass DMA audio port to audio drivers.
> +	 * Audio drivers should not ioremap it.
> +	 */
> +	hdmi.ip_data.ops->audio_get_dma_port(&port_offset, &port_size);
> +
> +	aud_res[0].start = res->start + port_offset;
> +	aud_res[0].end = aud_res[0].start + port_size - 1;
> +
> +	res = platform_get_resource(hdmi.pdev, IORESOURCE_DMA, 0);
> +	if (!res) {
> +		DSSERR("can't get IORESOURCE_DMA HDMI\n");
> +		return -EINVAL;
> +	}
> +
> +	/* Pass the audio DMA request resource to audio drivers. */
> +	aud_res[1].start = res->start;
> +
> +	/* create platform device for HDMI audio driver */
> +	hdmi.audio_pdev = platform_device_register_simple(
> +							  "omap_hdmi_audio",
> +							  -1, aud_res,
> +							   ARRAY_SIZE(aud_res));

Not a problem for the time being, but the above prevents us from having
two HDMI outputs. Perhaps you could use hdmi pdev's ID instead of -1 above?

Otherwise I think the series is ok.

 Tomi

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 897 bytes --]