Re: [PATCH v2 2/3] ARM: keystone: pm: switch to use generic pm domains

[Kevin Hilman <khilman@kernel.org>]

Grygorii Strashko <grygorii.strashko@ti.com> writes:

> Hi Santosh,
>
> On 10/21/2014 09:05 PM, Santosh Shilimkar wrote:
>> On 10/20/2014 05:56 AM, Grygorii Strashko wrote:
>>> This patch switches Keystone 2 PM code to use Generic PM domains
>>> instead of PM clock domains because of the lack of DT support
>>> for the last.
>>>
>>> Reviewed-by: Kevin Hilman <khilman@linaro.org>
>>> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
>>> ---
>>>   .../bindings/power/ti,keystone-powerdomain.txt     |  31 ++++++
>>>   arch/arm/mach-keystone/Kconfig                     |   1 +
>>>   arch/arm/mach-keystone/pm_domain.c                 | 112 
>>> ++++++++++++++-------
>>>   3 files changed, 107 insertions(+), 37 deletions(-)
>>>   create mode 100644 
>>> Documentation/devicetree/bindings/power/ti,keystone-powerdomain.txt
>>>
>>> diff --git 
>>> a/Documentation/devicetree/bindings/power/ti,keystone-powerdomain.txt 
>>> b/Documentation/devicetree/bindings/power/ti,keystone-powerdomain.txt
>>> new file mode 100644
>>> index 0000000..4bbf2aa
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/power/ti,keystone-powerdomain.txt
>>> @@ -0,0 +1,31 @@
>>> +* TI Keystone 2 Generic PM Controller
>>> +
>>> +The TI Keystone 2 Generic PM Controller is responsible for Clock gating
>>> +for each controlled IP module.
>>> +
>>> +Required properties:
>>> +- compatible: Should be "ti,keystone-powerdomain"
>>> +- #power-domain-cells: Should be 0, see below:
>>> +
>>> +The gpc node is a power-controller as documented by the generic power 
>>> domain
>> You renamed gpc but missed to fix the comment ? Pls update it.
>
> ok.
>
>> 
>>> +bindings in Documentation/devicetree/bindings/power/power_domain.txt.
>>> +
>>> +Example:
>>> +
>>> +    pm_controller: pm-controller {
>>> +        compatible = "ti,keystone-powerdomain";
>>> +        #power-domain-cells = <0>;
>>> +    };
>>> +
>>> +    netcp: netcp@2090000 {
>>> +        reg = <0x2620110 0x8>;
>>> +        reg-names = "efuse";
>>> +        ...
>>> +        #address-cells = <1>;
>>> +        #size-cells = <1>;
>>> +        ranges;
>>> +        power-domains = <&pm_controller>;
>>> +
>>> +        clocks = <&clkpa>, <&clkcpgmac>, <&chipclk12>;
>>> +        dma-coherent;
>>> +    }
>>> diff --git a/arch/arm/mach-keystone/Kconfig 
>>> b/arch/arm/mach-keystone/Kconfig
>>> index 98a156a..de43107 100644
>>> --- a/arch/arm/mach-keystone/Kconfig
>>> +++ b/arch/arm/mach-keystone/Kconfig
>>> @@ -9,6 +9,7 @@ config ARCH_KEYSTONE
>>>       select COMMON_CLK_KEYSTONE
>>>       select ARCH_SUPPORTS_BIG_ENDIAN
>>>       select ZONE_DMA if ARM_LPAE
>>> +    select PM_GENERIC_DOMAINS if PM
>>>       help
>>>         Support for boards based on the Texas Instruments Keystone 
>>> family of
>>>         SoCs.
>>> diff --git a/arch/arm/mach-keystone/pm_domain.c 
>>> b/arch/arm/mach-keystone/pm_domain.c
>>> index ca79dda..d58759d 100644
>>> --- a/arch/arm/mach-keystone/pm_domain.c
>>> +++ b/arch/arm/mach-keystone/pm_domain.c
>>> @@ -12,69 +12,107 @@
>>>    * version 2, as published by the Free Software Foundation.
>>>    */
>>>
>>> +#include <linux/clk.h>
>>>   #include <linux/init.h>
>>> -#include <linux/pm_runtime.h>
>>>   #include <linux/pm_clock.h>
>>> +#include <linux/pm_domain.h>
>>>   #include <linux/platform_device.h>
>>> -#include <linux/clk-provider.h>
>>>   #include <linux/of.h>
>>>
>>> -#ifdef CONFIG_PM_RUNTIME
>>> -static int keystone_pm_runtime_suspend(struct device *dev)
>>> +#ifdef CONFIG_PM_GENERIC_DOMAINS
>>> +
>>> +struct keystone_domain {
>>> +    struct generic_pm_domain genpd;
>>> +    struct device    *dev;
>>> +};
>>> +
>>> +void keystone_pm_domain_attach_dev(struct device *dev)
>>>   {
>>> +    struct clk *clk;
>>>       int ret;
>>> +    int i = 0;
>>>
>>>       dev_dbg(dev, "%s\n", __func__);
>>>
>>> -    ret = pm_generic_runtime_suspend(dev);
>>> -    if (ret)
>>> -        return ret;
>>> -
>>> -    ret = pm_clk_suspend(dev);
>>> +    ret = pm_clk_create(dev);
>>>       if (ret) {
>>> -        pm_generic_runtime_resume(dev);
>>> -        return ret;
>>> +        dev_err(dev, "pm_clk_create failed %d\n", ret);
>>> +        return;
>>> +    };
>>> +
>>> +    while ((clk = of_clk_get(dev->of_node, i++)) && !IS_ERR(clk)) {
>>> +        ret = pm_clk_add_clk(dev, clk);
>>> +        if (ret) {
>>> +            dev_err(dev, "pm_clk_add_clk failed %d\n", ret);
>>> +            goto clk_err;
>>> +        };
>>>       }
>>>
>>> -    return 0;
>>> +    if (!IS_ENABLED(CONFIG_PM_RUNTIME)) {
>> Can we not okkup two seperate callbacks instead of above check ?
>> I don't like this CONFIG check here. Its slightly better version of
>> ifdef in middle of the code.
>
> I've found more-less similar comment on patch
> "Re: [PATCH v3 1/3] power-domain: add power domain drivers for Rockchip platform"
> https://lkml.org/lkml/2014/10/17/257
>
> So, Would you like me to create patch which will enable clocks in pm_clk_add/_clk()
> in case !IS_ENABLED(CONFIG_PM_RUNTIME)

Yes, I think it's a good idea to propose that change and propose to
Rafael on linux-pm.  Be sure that myself, Ulf and Geert are Cc'd.

Thanks,

Kevin