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

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

Re-sent to loml, the original email was sent to lkml...

On 8/25/2010 1:30 PM, Cousson, Benoit wrote:
> On 8/25/2010 12:45 PM, Basak, Partha wrote:
>>
>>> From: Cousson, Benoit
>>> Sent: Tuesday, August 24, 2010 1:45 AM
>>>
>>> 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 */
>>>
>> OK
>>>>     /**
>>>> + * 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;
>>>
>> Not clear on your comment, wanted to take care of the scenario where a device is having multiple hwmods
>
> Which one? the one below or before? These comments are just about the
> readability of this patch.
>
>>> 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.
>>>
>> Agreed
>>
>>> 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.
>>
>> I see your point, but most of the functions in this layer are having omap_device * as the parameter, so I maintained consistency
>
> Since your function is anyway a private function, I don't see any reason
> to do that.
>
> FYI, I joined an updated version.
>
> Regards,
> Benoit
>
> ---
>   From d8a374c679b7f26229cf054520deb0ac416b7f4c Mon Sep 17 00:00:00 2001
> From: Basak, Partha<p-basak2@ti.com>
> Date: Mon, 23 Aug 2010 21:14:29 +0530
> Subject: [PATCH] OMAP: hwmod: handle opt clocks node using clk_add_alias
>
> 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 |   39
> +++++++++++++++++++++++++++++++++++++-
>    1 files changed, 38 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/plat-omap/omap_device.c
> b/arch/arm/plat-omap/omap_device.c
> index d2b1609..d876cec 100644
> --- a/arch/arm/plat-omap/omap_device.c
> +++ b/arch/arm/plat-omap/omap_device.c
> @@ -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>
> @@ -243,6 +244,40 @@ static inline struct omap_device
> *_find_by_pdev(struct platform_device *pdev)
>    	return container_of(pdev, struct omap_device, pdev);
>    }
>
> +/**
> + * _add_optional_clock_alias - Add clock alias for hwmod optional clocks
> + * @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 _add_optional_clock_alias(struct omap_device *od,
> +				      struct omap_hwmod *oh)
> +{
> +	int i;
> +	struct omap_hwmod_opt_clk *oc;
> +
> +	for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i>  0; i--, oc++) {
> +		int ret;
> +
> +		if (!oc->_clk || !IS_ERR(clk_get(&od->pdev.dev, oc->role)))
> +			return;
> +
> +		ret = clk_add_alias(oc->role, dev_name(&od->pdev.dev),
> +				    (char *)oc->clk, NULL);
> +		if (ret)
> +			pr_err("omap_device: clk_add_alias for %s failed\n",
> +			       oc->role);
> +	}
> +}
> +
>
>    /* Public functions for use by core code */
>
> @@ -421,8 +456,10 @@ struct omap_device *omap_device_build_ss(const char
> *pdev_name, int pdev_id,
>    	else
>    		ret = omap_device_register(od);
>
> -	for (i = 0; i<  oh_cnt; i++)
> +	for (i = 0; i<  oh_cnt; i++) {
>    		hwmods[i]->od = od;
> +		_add_optional_clock_alias(od, hwmods[i]);
> +	}
>
>    	if (ret)
>    		goto odbs_exit4;