[RFC PATCH v2 03/11] mfd: omap: control: core system control driver

Konstantin Baydarov kbaidarov at dev.rtsoft.ru
Wed Jun 20 10:13:54 EDT 2012

  Hi, Tony.

On 06/20/2012 02:22 PM, Tony Lindgren wrote:
> * Konstantin Baydarov <kbaidarov at dev.rtsoft.ru> [120618 04:36]:
>> This patch introduces a MFD core device driver for
>> OMAP system control module.
>> The control module allows software control of
>> various static modes supported by the device. It is
>> composed of two control submodules: general control
>> module and device (padconfiguration) control
>> module.
>> +++ linux-2.6/drivers/mfd/omap-control-core.c
> ...
>> +u32 omap_control_readl(u16 offset)
>> +{
>> +	return __raw_readl(omap_control_base + (offset));
>> +}
>> +
>> +void omap_control_writel(u32 val, u16 offset)
>> +{
>> +	__raw_writel(val, omap_control_base + (offset));
>> +}
> There should not be any need to have the individual drivers use
> these. Please instead just set up something where individual drivers
> register with the control module core, and get their own iobase
> returned so they can use readl/writel and behave like normal device
> drivers.
IIUC one of the reasons drivers/mfd/omap-control-core.c introduction is replacement of arch/arm/mach-omap2/control.c. control.c provides omap_ctrl_readl/omap_ctrl_writel API which are heavily used in arch/arm/mach-omap2/:

So,the same API set (omap_control_readl/omap_control_writel) was added to omap-control-core.c.

If omap-control-core.c should only service users from driver/ directory, than I agree - we can remove
omap_control_readl/omap_control_writel from omap-control-core.c.
  But IIUC you are agree to "switch" arch/arm/mach-omap2/id.c from control.c to omap-control-core.c. If arch/arm/mach-omap2/id.c is switched to control.c, then I guess all arch/arm/mach-omap2/*.c should be "switched" to omap-control-core.c as well. But this means that omap-control-core.c should provide omap_control_readl/omap_control_writel API.

    Konstantin Baydarov.

> Regards,
> Tony
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