On Fri, 2022-10-21 at 10:41 +0200, AngeloGioacchino Del Regno wrote:
> Il 21/10/22 10:27, Trevor Wu ha scritto:
> > Add mt8188 audio cg clock control. Audio clock gates are registered
> > to CCF
> > for reference count and clock parent management.
> >
> > Signed-off-by: Trevor Wu <trevor.wu@xxxxxxxxxxxx>
> > ---
> > sound/soc/mediatek/mt8188/mt8188-audsys-clk.c | 206
> > ++++++++++++++++++
> > sound/soc/mediatek/mt8188/mt8188-audsys-clk.h | 15 ++
> > .../soc/mediatek/mt8188/mt8188-audsys-clkid.h | 83 +++++++
> > 3 files changed, 304 insertions(+)
> > create mode 100644 sound/soc/mediatek/mt8188/mt8188-audsys-clk.c
> > create mode 100644 sound/soc/mediatek/mt8188/mt8188-audsys-clk.h
> > create mode 100644 sound/soc/mediatek/mt8188/mt8188-audsys-
> > clkid.h
> >
> > diff --git a/sound/soc/mediatek/mt8188/mt8188-audsys-clk.c
> > b/sound/soc/mediatek/mt8188/mt8188-audsys-clk.c
> > new file mode 100644
> > index 000000000000..1f294231d4c2
> > --- /dev/null
> > +++ b/sound/soc/mediatek/mt8188/mt8188-audsys-clk.c
> > @@ -0,0 +1,206 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * mt8188-audsys-clk.c -- MediaTek 8188 audsys clock control
> > + *
> > + * Copyright (c) 2022 MediaTek Inc.
> > + * Author: Chun-Chia Chiu <chun-chia.chiu@xxxxxxxxxxxx>
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/clk-provider.h>
> > +#include <linux/clkdev.h>
> > +#include "mt8188-afe-common.h"
> > +#include "mt8188-audsys-clk.h"
> > +#include "mt8188-audsys-clkid.h"
> > +#include "mt8188-reg.h"
> > +
> > +struct afe_gate {
> > + int id;
> > + const char *name;
> > + const char *parent_name;
> > + int reg;
> > + u8 bit;
> > + const struct clk_ops *ops;
> > + unsigned long flags;
> > + u8 cg_flags;
> > +};
> > +
> > +#define GATE_AFE_FLAGS(_id, _name, _parent, _reg, _bit, _flags,
> > _cgflags) {\
> > + .id = _id, \
> > + .name = _name, \
> > + .parent_name = _parent, \
> > + .reg = _reg, \
> > + .bit = _bit, \
> > + .flags = _flags, \
> > + .cg_flags = _cgflags, \
> > + }
> > +
> > +#define GATE_AFE(_id, _name, _parent, _reg, _bit) \
> > + GATE_AFE_FLAGS(_id, _name, _parent, _reg, _bit, \
> > + CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED,
> > CLK_GATE_SET_TO_DISABLE)
>
> Can you please explain what's the reason for CLK_IGNORE_UNUSED here?
> Maybe we can solve some issue that you're facing in a cleaner way.
>
> Regards,
> Angelo
Hi Angelo,
Because clk_disable_unused() calls clk_core_is_enabled(), register
access happens in is_enabled() ops.
At the moment, the power for register access is not enabled, so the
register read results in CPU hang.
That's why I added CLK_IGNORE_UNUSED here, but it can't resolve all
issues. Actually, we met same problem when "cat
/sys/kernel/debug/clk/clk_summary" is used. We are still suffering the
problem.
I'm not sure if I can implement clk ops by myself, and exclude the
registration of is_enabled() ops.
Thanks,
Trevor
>
