Re: [PATCH] OMAP: HWMOD: Handle opt clocks using clk_add_alias

["Cousson, Benoit" <b-cousson@ti.com>]

Hi Partha,

On 8/23/2010 5:44 PM, Basak, Partha wrote:
> From: Basak, Partha<p-basak2@ti.com>
>
> For every optional clock present per hwmod per omap-device, this function
> adds an entry in the clocks list of the form<dev-id=dev_name, con-id=role>,
> if an entry is already present in the list of the form<dev-id=NULL, con-id=role>.
>
> The function is called from within the framework inside omap_device_build_ss(),
> after omap_device_register.
>
> This allows drivers to get a pointer to its optional clocks based on its role
> by calling clk_get(<dev*>,<role>).
>
> Link to discussions related to this patch:
> http://www.spinics.net/lists/linux-omap/msg34809.html
>
> Signed-off-by: Charulatha V<charu@ti.com>
> Signed-off-by: Basak, Partha<p-basak2@ti.com>
> Signed-off-by: Benoit Cousson<b-cousson@ti.com>
> Signed-off-by: Rajendra Nayak<rnayak@ti.com>
>
> Cc: Paul Walmsley<paul@pwsan.com>
> Cc: Kevin Hilman<khilman@deeprootsystems.com>
> ---
>   arch/arm/plat-omap/omap_device.c |   31 ++++++++++++++++++++++++++++++-
>   1 files changed, 30 insertions(+), 1 deletions(-)
>
> Index: linux-omap-pm/arch/arm/plat-omap/omap_device.c
> ===================================================================
> --- linux-omap-pm.orig/arch/arm/plat-omap/omap_device.c	2010-08-18 02:48:30.789079550 +0530
> +++ linux-omap-pm/arch/arm/plat-omap/omap_device.c	2010-08-24 07:19:43.637080138 +0530
> @@ -82,6 +82,7 @@
>   #include<linux/slab.h>
>   #include<linux/err.h>
>   #include<linux/io.h>
> +#include<linux/clk.h>
>
>   #include<plat/omap_device.h>
>   #include<plat/omap_hwmod.h>
> @@ -243,7 +244,6 @@ static inline struct omap_device *_find_
>   	return container_of(pdev, struct omap_device, pdev);
>   }
>
> -

That fix is not related to the patch subject.

>   /* Public functions for use by core code */
>
>   /**
> @@ -271,6 +271,47 @@ int omap_device_count_resources(struct o
>   }

This is not a public function, so you should move it before the /* 
Public functions for use by core code */

>   /**
> + * omap_device_add_opt_clk_alias - Add alias for optional clocks in the
> + * clocks list.
> + *
> + * @od: struct omap_device *od
> + *
> + * For every optional clock present per hwmod per omap-device, this function
> + * adds an entry in the clocks list of the form<dev-id=dev_name, con-id=role>
> + * if an entry is already present in it with the form<dev-id=NULL,con-id=role>
> + *
> + * The function is called from inside omap_device_build_ss(),
> + * after omap_device_register.
> + *
> + * This allows drivers to get a pointer to its optional clocks based on its role
> + * by calling clk_get(<dev*>,<role>).
> + */
> +
> +static void omap_device_add_opt_clk_alias(struct omap_device *od)
> +{
> +	int i, j;
> +	struct omap_hwmod_opt_clk *oc;
> +	struct omap_hwmod *oh;
> +
> +	for (i = 0, oh = *od->hwmods; i<  od->hwmods_cnt; i++, oh++)

You can avoid that iteration and the extra level of indentation by 
re-using the iteration done before the call to that function.

> +		/* Add Clock alias for all optional clocks*/
> +		for (j = oh->opt_clks_cnt, oc = oh->opt_clks;
> +			j>  0; j--, oc++) {
> +			if ((oc->_clk)&&
> +			(IS_ERR(clk_get(&od->pdev.dev, oc->role)))) {
> +				int ret;

You can avoid the indentation by returning in case of error.
You can avoid as well 2 pairs of parens.

> +
> +				ret = clk_add_alias(oc->role,
> +					dev_name(&od->pdev.dev),
> +					(char *)oc->clk, NULL);

The indentation is not align with the inner parameters... which is not 
easy in your case due to the too many indentation level you have in this 
function.

> +				if (ret)
> +					dev_err(&od->pdev.dev, "omap_device:\

This is not correct way of splitting long string, use "omap_device:" 
instead.

Even if dev_err is usable because you have the dev pointer, it is in 
fact an error from the omap_device code code, so using pr_err is 
probably more appropriate (TBC).

> +					clk_add_alias for %s failed\n",
> +					oc->role);
> +			}
> +		}
> +}
> +/**
>    * omap_device_fill_resources - fill in array of struct resource
>    * @od: struct omap_device *
>    * @res: pointer to an array of struct resource to be filled in
> @@ -424,6 +465,12 @@ struct omap_device *omap_device_build_ss
>   	for (i = 0; i<  oh_cnt; i++)
>   		hwmods[i]->od = od;

You can call a per hwmod API here in order to avoid the iteration inside 
the function.

>
> +	/*
> +	 * Add Clock alias for all optional
> +	 * clocks present in the hwmod
> +	 */

That comment is not bringing any new information, the function is 
already documented in the kernel doc comment.

> +	omap_device_add_opt_clk_alias(od);
> +
>   	if (ret)
>   		goto odbs_exit4;
>

Regards,
Benoit