Re: [RFC 3/7] OMAP: Introduce voltage domain pointer and device specific set rate and get rate in device opp structures.

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

Hi Thara,

On 7/2/2010 12:18 PM, Gopinath, Thara wrote:
> This patch extends the device opp structure to contain
> info about the voltage domain to which the device belongs to
> and to contain pointers to scale the operating rate of the
> device. This patch also adds an API in the opp layer that
> can be used by the voltage layer to get a list of all the
> scalable devices belonging to a particular voltage domain.
> This API is to be typically called only once by the voltage
> layer per voltage domain instance and the device list should
> be stored. This approach makes it easy during dvfs to scale
> all the devices associated with a voltage domain and then
> scale the voltage domain.
>
> Signed-off-by: Thara Gopinath<thara@ti.com>
> ---
>   arch/arm/plat-omap/include/plat/opp.h |   37 +++++++++++++++++++++++++-
>   arch/arm/plat-omap/opp.c              |   47 +++++++++++++++++++++++++-------
>   2 files changed, 72 insertions(+), 12 deletions(-)
>
> diff --git a/arch/arm/plat-omap/include/plat/opp.h b/arch/arm/plat-omap/include/plat/opp.h
> index 893731f..15e1e70 100644
> --- a/arch/arm/plat-omap/include/plat/opp.h
> +++ b/arch/arm/plat-omap/include/plat/opp.h
> @@ -16,6 +16,7 @@
>
>   #include<linux/err.h>
>   #include<linux/cpufreq.h>
> +#include<linux/clk.h>
>
>   #include<plat/common.h>
>
> @@ -38,21 +39,45 @@
>    */
>   struct omap_opp_def {
>   	char *hwmod_name;
> +	char *vdd_name;

vdd should be an attribute of hwmod. For one hwmod in a soc we will 
always have the same vdd.
That will avoid to duplicate information and to have to populate that in 
each OPP entry (cf patch 6).

>
>   	unsigned long freq;
>   	unsigned long u_volt;
>
> +	int (*set_rate)(struct device *dev, unsigned long rate);
> +	unsigned long (*get_rate) (struct device *dev);

We might already discussed that, but why should we store that per OPP?
Cannot we store that per device?

Regards,
Benoit