Subject: [RFC PATCH] ARM: OMAP2+: omap-device: Do not overwrite resources allocated by OF layer

From: [email-masked] (Peter Ujfalusi)
Date: Wed, 05 Sep 2012 12:20:06 +0300

On 08/29/2012 12:48 PM, Vaibhav Hiremath wrote:
> With the new devices (like, AM33XX and OMAP5) we now only support
> DT boot mode of operation and now it is the time to start killing
> slowly the dependency on hwmod, so with this patch, we are starting
> with device resources.
> The idea here is implemented considering to both boot modes -
>   - DT boot mode
>     OF framework will construct the resource structure (currently
>     does for MEM & IRQ resource) and we should respect/use these
>     resources, killing hwmod dependency.
>     If pdev->num_resources > 0, we assume that MEM & IRQ resources
>     have been allocated by OF layer already (through DTB).
> 
>     Once DMA resource is available from OF layer, we should
>     kill filling any resources from hwmod.
> 
>   - Non-DT boot mode
>     Here, pdev->num_resources = 0, and we should get all the
>     resources from hwmod (following existing steps)
> 
> Signed-off-by: Vaibhav Hiremath <[email-masked]>
> Cc: Benoit Cousson <[email-masked]>
> Cc: Tony Lindgren <[email-masked]>
> Cc: Paul Walmsley <[email-masked]>
> Cc: Kevin Hilman <[email-masked]>
> ---
> This patch is tested on BeagleBone and AM37xEVM.

I tried this on OMAP3 (with McBSP/twl4030-audio/omap-twl4030 DT boot), OMAP4
(McPDM, DMIC DT), and on OMAP5 (McPDM, DMIC DT).
I have sent the patches needed for the dtsi files to probe the audio related
IPs with this patch.

Tested-by: Peter Ujfalusi <[email-masked]>

> 
> Why RFC?
> Still we have function duplication omap_device_fill_resources() and
> omap_device_fill_dma_resources(), we can actually split the function
> into 3 resources and avoid duplication -
>   - omap_device_fill_dma_resources()
>   - omap_device_fill_mem_resources()
>   - omap_device_fill_irq_resources()
> 
> Actually I wanted to clean it further but thought of getting
> feedback first and then proceed further.
> 
>  arch/arm/mach-omap2/omap_hwmod.c             |   27 ++++++++++
>  arch/arm/plat-omap/include/plat/omap_hwmod.h |    1 +
>  arch/arm/plat-omap/omap_device.c             |   72 +++++++++++++++++++++----
>  3 files changed, 88 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
> index 31ec283..edabfb3 100644
> --- a/arch/arm/mach-omap2/omap_hwmod.c
> +++ b/arch/arm/mach-omap2/omap_hwmod.c
> @@ -3330,6 +3330,33 @@ int omap_hwmod_fill_resources(struct omap_hwmod *oh, struct resource *res)
>  }
> 
>  /**
> + * omap_hwmod_fill_dma_resources - fill struct resource array with dma data
> + * @oh: struct omap_hwmod *
> + * @res: pointer to the array of struct resource to fill
> + *
> + * Fill the struct resource array @res with dma resource data from the
> + * omap_hwmod @oh.  Intended to be called by code that registers
> + * omap_devices.  See also omap_hwmod_count_resources().  Returns the
> + * number of array elements filled.
> + */
> +int omap_hwmod_fill_dma_resources(struct omap_hwmod *oh, struct resource *res)
> +{
> +	int i, sdma_reqs_cnt;
> +	int r = 0;
> +
> +	sdma_reqs_cnt = _count_sdma_reqs(oh);
> +	for (i = 0; i < sdma_reqs_cnt; i++) {
> +		(res + r)->name = (oh->sdma_reqs + i)->name;
> +		(res + r)->start = (oh->sdma_reqs + i)->dma_req;
> +		(res + r)->end = (oh->sdma_reqs + i)->dma_req;
> +		(res + r)->flags = IORESOURCE_DMA;
> +		r++;
> +	}
> +
> +	return r;
> +}
> +
> +/**
>   * omap_hwmod_get_resource_byname - fetch IP block integration data by name
>   * @oh: struct omap_hwmod * to operate on
>   * @type: one of the IORESOURCE_* constants from include/linux/ioport.h
> diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h
> index 9b9646c..0533073 100644
> --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h
> +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h
> @@ -615,6 +615,7 @@ int omap_hwmod_softreset(struct omap_hwmod *oh);
> 
>  int omap_hwmod_count_resources(struct omap_hwmod *oh);
>  int omap_hwmod_fill_resources(struct omap_hwmod *oh, struct resource *res);
> +int omap_hwmod_fill_dma_resources(struct omap_hwmod *oh, struct resource *res);
>  int omap_hwmod_get_resource_byname(struct omap_hwmod *oh, unsigned int type,
>  				   const char *name, struct resource *res);
> 
> diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
> index c490240..fd15a3a 100644
> --- a/arch/arm/plat-omap/omap_device.c
> +++ b/arch/arm/plat-omap/omap_device.c
> @@ -486,6 +486,33 @@ static int omap_device_fill_resources(struct omap_device *od,
>  }
> 
>  /**
> + * omap_device_fill_dma_resources - fill in array of struct resource with dma resources
> + * @od: struct omap_device *
> + * @res: pointer to an array of struct resource to be filled in
> + *
> + * Populate one or more empty struct resource pointed to by @res with
> + * the dma resource data for this omap_device @od.  Used by
> + * omap_device_alloc() after calling omap_device_count_resources().
> + *
> + * Ideally this function would not be needed at all.  If we have
> + * mechanism to get dma resources from DT.
> + *
> + * Returns 0.
> + */
> +static int omap_device_fill_dma_resources(struct omap_device *od,
> +				      struct resource *res)
> +{
> +	int i, r;
> +
> +	for (i = 0; i < od->hwmods_cnt; i++) {
> +		r = omap_hwmod_fill_dma_resources(od->hwmods[i], res);
> +		res += r;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
>   * omap_device_alloc - allocate an omap_device
>   * @pdev: platform_device that will be included in this omap_device
>   * @oh: ptr to the single omap_hwmod that backs this omap_device
> @@ -524,24 +551,45 @@ struct omap_device *omap_device_alloc(struct platform_device *pdev,
>  	od->hwmods = hwmods;
>  	od->pdev = pdev;
> 
> +	res_count = omap_device_count_resources(od);
>  	/*
> -	 * HACK: Ideally the resources from DT should match, and hwmod
> -	 * should just add the missing ones. Since the name is not
> -	 * properly populated by DT, stick to hwmod resources only.
> +	 * DT Boot:
> +	 *   OF framework will construct the resource structure (currently
> +	 *   does for MEM & IRQ resource) and we should respect/use these
> +	 *   resources, killing hwmod dependency.
> +	 *   If pdev->num_resources > 0, we assume that MEM & IRQ resources
> +	 *   have been allocated by OF layer already (through DTB).
> +	 *
> +	 * Non-DT Boot:
> +	 *   Here, pdev->num_resources = 0, and we should get all the
> +	 *   resources from hwmod.
> +	 *
> +	 * TODO: Once DMA resource is available from OF layer, we should
> +	 *   kill filling any resources from hwmod.
>  	 */
> -	if (pdev->num_resources && pdev->resource)
> -		dev_warn(&pdev->dev, "%s(): resources already allocated %d\n",
> -			__func__, pdev->num_resources);
> -
> -	res_count = omap_device_count_resources(od);
> -	if (res_count > 0) {
> -		dev_dbg(&pdev->dev, "%s(): resources allocated from hwmod %d\n",
> -			__func__, res_count);
> +	if (res_count > pdev->num_resources) {
> +		/* Allocate resources memory to account for new resources */
>  		res = kzalloc(sizeof(struct resource) * res_count, GFP_KERNEL);
>  		if (!res)
>  			goto oda_exit3;
> 
> -		omap_device_fill_resources(od, res);
> +		/*
> +		 * If pdev->num_resources > 0, then assume that,
> +		 * MEM and IRQ resources will only come from DT and only
> +		 * fill DMA resource from hwmod layer.
> +		 */
> +		if (pdev->num_resources && pdev->resource) {
> +			dev_dbg(&pdev->dev, "%s(): resources already allocated %d\n",
> +					__func__, res_count);
> +			memcpy(res, pdev->resource,
> +				sizeof(struct resource) * pdev->num_resources);
> +			omap_device_fill_dma_resources(od,
> +					&res[pdev->num_resources]);
> +		} else {
> +			dev_dbg(&pdev->dev, "%s(): using resources from hwmod %d\n",
> +					__func__, res_count);
> +			omap_device_fill_resources(od, res);
> +		}
> 
>  		ret = platform_device_add_resources(pdev, res, res_count);
>  		kfree(res);
> --
> 1.7.0.4
> 
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-- 
P?ter