> -----Original Message-----
> From: Sudeep Holla <sudeep.holla@xxxxxxx>
> Sent: Monday, February 21, 2022 6:52 PM
> To: Edwin Chiu <edwinchiu0505tw@xxxxxxxxx>
> Cc: Edwin Chiu 邱垂峰 <edwin.chiu@xxxxxxxxxxx>; robh+dt@xxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; rafael@xxxxxxxxxx; Sudeep Holla <sudeep.holla@xxxxxxx>;
> daniel.lezcano@xxxxxxxxxx; linux-pm@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v5] cpuidle: sunplus: Create cpuidle driver for sunplus sp7021
>
> On Mon, Feb 21, 2022 at 03:26:18PM +0800, Edwin Chiu wrote:
> > Create cpuidle driver for sunplus sp7021 chip
> >
> > Signed-off-by: Edwin Chiu <edwinchiu0505tw@xxxxxxxxx>
> > ---
> > Changes in v3
> > - Rearrangement #include sequence
> > - Change remark style to /*~*/
> > - Align author email address to same as sob
> > - Optimal code
> > Changes in v4
> > - According Rob Herringrobh's comment
> > There is no need for this binding.
> > Just wanting a different driver is not a reason
> > for a duplicate schema.
> > So remove yaml file and submit driver again.
> > Changes in v5
> > - According Krzysztof's comment
> > You either use appropriate compatible in DT
> > or add your compatible to cpuidle-arm.
> > Even if this did not work, then the solution is to
> > use common parts, not to duplicate entire driver.
> > According Sudeep's comment
> > In short NACK for any dedicated driver for this platform,
> > use the generic cpuidle-arm driver with appropriate platform hooks
> > Create cpuidle-sunplus.c in arch/arm/mach-sunplus/
> > for hook generic cpuidle-arm driver
> >
> > MAINTAINERS | 6 ++
> > arch/arm/mach-sunplus/cpuidle-sunplus.c | 88 +++++++++++++++++
> > include/linux/platform_data/cpuidle-sunplus.h | 12 ++++
> > 3 files changed, 106 insertions(+)
> > create mode 100644 arch/arm/mach-sunplus/cpuidle-sunplus.c
> > create mode 100644 include/linux/platform_data/cpuidle-sunplus.h
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS index e0dca8f..5c96428 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -18252,6 +18252,12 @@ L: netdev@xxxxxxxxxxxxxxx
> > S: Maintained
> > F: drivers/net/ethernet/dlink/sundance.c
> >
> > +SUNPLUS CPUIDLE DRIVER
> > +M: Edwin Chiu <edwinchiu0505tw@xxxxxxxxx>
> > +S: Maintained
> > +F: arch/arm/mach-sunplus/cpuidle-sunplus.c
> > +F: include/linux/platform_data/cpuidle-sunplus.h
> > +
> > SUPERH
> > M: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
> > M: Rich Felker <dalias@xxxxxxxx>
> > diff --git a/arch/arm/mach-sunplus/cpuidle-sunplus.c
> > b/arch/arm/mach-sunplus/cpuidle-sunplus.c
> > new file mode 100644
> > index 0000000..e9d9738
> > --- /dev/null
> > +++ b/arch/arm/mach-sunplus/cpuidle-sunplus.c
> > @@ -0,0 +1,88 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * SP7021 cpu idle Driver.
> > + * Copyright (C) Sunplus Tech / Tibbo Tech.
> > + */
> > +#define pr_fmt(fmt) "CPUidle arm: " fmt
> > +
> > +#include <linux/cpuidle.h>
> > +#include <linux/of_device.h>
> > +#include <linux/platform_data/cpuidle-sunplus.h>
> > +
> > +#include <asm/cpuidle.h>
> > +
> > +typedef int (*idle_fn)(void);
> > +
> > +static DEFINE_PER_CPU(idle_fn*, sp7021_idle_ops);
> > +
> > +static int sp7021_cpuidle_enter(unsigned long index) {
> > + return __this_cpu_read(sp7021_idle_ops)[index]();
> > +}
> > +static int sp7021_cpu_spc(void)
> > +{
> > + cpu_v7_do_idle(); /* idle to WFI */
> > + return 0;
> > +}
>
> You really don't need a cpuidle driver to just WFI for any states.
> Add the driver when you have something non WFI in the suspend function.
>
> > +static const struct of_device_id sp7021_idle_state_match[] = {
> > + { .compatible = "arm,idle-state", .data = sp7021_cpu_spc },
> > + { },
> > +};
>
> This is better than adding new driver like you did in previous version.
>
> I did a quick check but couldn't figure out. How do cpus get switched ON or OFF on this platform(for
> example during CPU hotplug) ?
>
> --
> Regards,
> Sudeep
In this patch, I just want to submit cpuidle function.
So there have no cpu hotplug function now.
邱垂峰 EdwinChiu
智能運算專案
T: +886-3-5786005 ext.2590
edwin.chiu@xxxxxxxxxxx
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