From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: Neil Armstrong <narmstrong@baylibre.com>,
linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org,
thierry.reding@gmail.com, linux-amlogic@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 04/14] pwm: meson: change MISC_CLK_SEL_WIDTH to MISC_CLK_SEL_MASK
Date: Tue, 28 May 2019 20:04:45 +0200 [thread overview]
Message-ID: <CAFBinCCWYf4TJ8GTL3PrHMRfL3=Ma-QrTAGSyAp5OQc0M-67Jg@mail.gmail.com> (raw)
In-Reply-To: <20190527180047.nfsjfqs22coyqmvp@pengutronix.de>
Hi Uwe,
On Mon, May 27, 2019 at 8:00 PM Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> wrote:
>
> On Mon, May 27, 2019 at 07:46:43PM +0200, Martin Blumenstingl wrote:
> > Hi Neil,
> >
> > On Mon, May 27, 2019 at 2:26 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
> > >
> > > On 25/05/2019 20:11, Martin Blumenstingl wrote:
> > > > MISC_CLK_SEL_WIDTH is only used in one place where it's converted into
> > > > a bit-mask. Rename and change the macro to be a bit-mask so that
> > > > conversion is not needed anymore. No functional changes intended.
> > > >
> > > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> > > > ---
> > > > drivers/pwm/pwm-meson.c | 4 ++--
> > > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
> > > > index c62a3ac924d0..84b28ba0f903 100644
> > > > --- a/drivers/pwm/pwm-meson.c
> > > > +++ b/drivers/pwm/pwm-meson.c
> > > > @@ -33,7 +33,7 @@
> > > > #define MISC_A_CLK_DIV_SHIFT 8
> > > > #define MISC_B_CLK_SEL_SHIFT 6
> > > > #define MISC_A_CLK_SEL_SHIFT 4
> > > > -#define MISC_CLK_SEL_WIDTH 2
> > > > +#define MISC_CLK_SEL_MASK 0x3
> > >
> > > NIT I would have used GENMASK here
> > that was my initial idea but I decided against it.
> > the variant I came up with was: #define MISC_CLK_SEL_MASK GENMASK(1, 0)
> >
> > however, the actual offset is either 4 or 6 (depending on the PWM channel)
> > and I felt that duplicating the macro would just make it more complicated
> > so instead I chose to be consistent with MISC_CLK_DIV_MASK
>
> An option would be:
>
> #define MISC_CLK_SEL_MASK(hwid) GENMASK(1 + 4 * (hwid), 0 + 4 * (hwid))
>
> (Note I didn't check a manual to the 4 above is probably wrong.)
that (or at least something similar) will work
the catch here is: we use it to initialize the mux clock and the
common clock framework expects us to set "shift" and "mask", while
mask starts at bit 0 instead of shift
this is how the current code is being used at the moment:
channel->mux.shift = meson_pwm_per_channel_data[i].clk_sel_shift;
channel->mux.mask = MISC_CLK_SEL_MASK;
so with MISC_CLK_SEL_MASK this would become:
channel->mux.shift = meson_pwm_per_channel_data[i].clk_sel_shift;
channel->mux.mask = MISC_CLK_SEL_MASK(i) >> channel->mux.shift;
or we could dynamically determine the "shift" using ffs or friends
my own brain parses the variant from the patch best
I'm happy to change it though if we can find something "better"
Martin
WARNING: multiple messages have this Message-ID (diff)
From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: linux-pwm@vger.kernel.org,
Neil Armstrong <narmstrong@baylibre.com>,
linux-kernel@vger.kernel.org, thierry.reding@gmail.com,
linux-amlogic@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 04/14] pwm: meson: change MISC_CLK_SEL_WIDTH to MISC_CLK_SEL_MASK
Date: Tue, 28 May 2019 20:04:45 +0200 [thread overview]
Message-ID: <CAFBinCCWYf4TJ8GTL3PrHMRfL3=Ma-QrTAGSyAp5OQc0M-67Jg@mail.gmail.com> (raw)
In-Reply-To: <20190527180047.nfsjfqs22coyqmvp@pengutronix.de>
Hi Uwe,
On Mon, May 27, 2019 at 8:00 PM Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> wrote:
>
> On Mon, May 27, 2019 at 07:46:43PM +0200, Martin Blumenstingl wrote:
> > Hi Neil,
> >
> > On Mon, May 27, 2019 at 2:26 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
> > >
> > > On 25/05/2019 20:11, Martin Blumenstingl wrote:
> > > > MISC_CLK_SEL_WIDTH is only used in one place where it's converted into
> > > > a bit-mask. Rename and change the macro to be a bit-mask so that
> > > > conversion is not needed anymore. No functional changes intended.
> > > >
> > > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> > > > ---
> > > > drivers/pwm/pwm-meson.c | 4 ++--
> > > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
> > > > index c62a3ac924d0..84b28ba0f903 100644
> > > > --- a/drivers/pwm/pwm-meson.c
> > > > +++ b/drivers/pwm/pwm-meson.c
> > > > @@ -33,7 +33,7 @@
> > > > #define MISC_A_CLK_DIV_SHIFT 8
> > > > #define MISC_B_CLK_SEL_SHIFT 6
> > > > #define MISC_A_CLK_SEL_SHIFT 4
> > > > -#define MISC_CLK_SEL_WIDTH 2
> > > > +#define MISC_CLK_SEL_MASK 0x3
> > >
> > > NIT I would have used GENMASK here
> > that was my initial idea but I decided against it.
> > the variant I came up with was: #define MISC_CLK_SEL_MASK GENMASK(1, 0)
> >
> > however, the actual offset is either 4 or 6 (depending on the PWM channel)
> > and I felt that duplicating the macro would just make it more complicated
> > so instead I chose to be consistent with MISC_CLK_DIV_MASK
>
> An option would be:
>
> #define MISC_CLK_SEL_MASK(hwid) GENMASK(1 + 4 * (hwid), 0 + 4 * (hwid))
>
> (Note I didn't check a manual to the 4 above is probably wrong.)
that (or at least something similar) will work
the catch here is: we use it to initialize the mux clock and the
common clock framework expects us to set "shift" and "mask", while
mask starts at bit 0 instead of shift
this is how the current code is being used at the moment:
channel->mux.shift = meson_pwm_per_channel_data[i].clk_sel_shift;
channel->mux.mask = MISC_CLK_SEL_MASK;
so with MISC_CLK_SEL_MASK this would become:
channel->mux.shift = meson_pwm_per_channel_data[i].clk_sel_shift;
channel->mux.mask = MISC_CLK_SEL_MASK(i) >> channel->mux.shift;
or we could dynamically determine the "shift" using ffs or friends
my own brain parses the variant from the patch best
I'm happy to change it though if we can find something "better"
Martin
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: linux-pwm@vger.kernel.org,
Neil Armstrong <narmstrong@baylibre.com>,
linux-kernel@vger.kernel.org, thierry.reding@gmail.com,
linux-amlogic@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 04/14] pwm: meson: change MISC_CLK_SEL_WIDTH to MISC_CLK_SEL_MASK
Date: Tue, 28 May 2019 20:04:45 +0200 [thread overview]
Message-ID: <CAFBinCCWYf4TJ8GTL3PrHMRfL3=Ma-QrTAGSyAp5OQc0M-67Jg@mail.gmail.com> (raw)
In-Reply-To: <20190527180047.nfsjfqs22coyqmvp@pengutronix.de>
Hi Uwe,
On Mon, May 27, 2019 at 8:00 PM Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> wrote:
>
> On Mon, May 27, 2019 at 07:46:43PM +0200, Martin Blumenstingl wrote:
> > Hi Neil,
> >
> > On Mon, May 27, 2019 at 2:26 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
> > >
> > > On 25/05/2019 20:11, Martin Blumenstingl wrote:
> > > > MISC_CLK_SEL_WIDTH is only used in one place where it's converted into
> > > > a bit-mask. Rename and change the macro to be a bit-mask so that
> > > > conversion is not needed anymore. No functional changes intended.
> > > >
> > > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> > > > ---
> > > > drivers/pwm/pwm-meson.c | 4 ++--
> > > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > > >
> > > > diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
> > > > index c62a3ac924d0..84b28ba0f903 100644
> > > > --- a/drivers/pwm/pwm-meson.c
> > > > +++ b/drivers/pwm/pwm-meson.c
> > > > @@ -33,7 +33,7 @@
> > > > #define MISC_A_CLK_DIV_SHIFT 8
> > > > #define MISC_B_CLK_SEL_SHIFT 6
> > > > #define MISC_A_CLK_SEL_SHIFT 4
> > > > -#define MISC_CLK_SEL_WIDTH 2
> > > > +#define MISC_CLK_SEL_MASK 0x3
> > >
> > > NIT I would have used GENMASK here
> > that was my initial idea but I decided against it.
> > the variant I came up with was: #define MISC_CLK_SEL_MASK GENMASK(1, 0)
> >
> > however, the actual offset is either 4 or 6 (depending on the PWM channel)
> > and I felt that duplicating the macro would just make it more complicated
> > so instead I chose to be consistent with MISC_CLK_DIV_MASK
>
> An option would be:
>
> #define MISC_CLK_SEL_MASK(hwid) GENMASK(1 + 4 * (hwid), 0 + 4 * (hwid))
>
> (Note I didn't check a manual to the 4 above is probably wrong.)
that (or at least something similar) will work
the catch here is: we use it to initialize the mux clock and the
common clock framework expects us to set "shift" and "mask", while
mask starts at bit 0 instead of shift
this is how the current code is being used at the moment:
channel->mux.shift = meson_pwm_per_channel_data[i].clk_sel_shift;
channel->mux.mask = MISC_CLK_SEL_MASK;
so with MISC_CLK_SEL_MASK this would become:
channel->mux.shift = meson_pwm_per_channel_data[i].clk_sel_shift;
channel->mux.mask = MISC_CLK_SEL_MASK(i) >> channel->mux.shift;
or we could dynamically determine the "shift" using ffs or friends
my own brain parses the variant from the patch best
I'm happy to change it though if we can find something "better"
Martin
_______________________________________________
linux-amlogic mailing list
linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic
next prev parent reply other threads:[~2019-05-28 18:04 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-25 18:11 [PATCH 00/14] pwm-meson: cleanups and improvements Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` [PATCH 01/14] pwm: meson: unify the parameter list of meson_pwm_{enable,disable} Martin Blumenstingl
2019-05-25 18:11 ` [PATCH 01/14] pwm: meson: unify the parameter list of meson_pwm_{enable, disable} Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:25 ` Neil Armstrong
2019-05-27 12:25 ` Neil Armstrong
2019-05-27 12:25 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 02/14] pwm: meson: use devm_clk_get_optional() to get the input clock Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:25 ` Neil Armstrong
2019-05-27 12:25 ` Neil Armstrong
2019-05-27 12:25 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 03/14] pwm: meson: use GENMASK and FIELD_PREP for the lo and hi values Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:25 ` Neil Armstrong
2019-05-27 12:25 ` Neil Armstrong
2019-05-27 12:25 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 04/14] pwm: meson: change MISC_CLK_SEL_WIDTH to MISC_CLK_SEL_MASK Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:26 ` Neil Armstrong
2019-05-27 12:26 ` Neil Armstrong
2019-05-27 12:26 ` Neil Armstrong
2019-05-27 17:46 ` Martin Blumenstingl
2019-05-27 17:46 ` Martin Blumenstingl
2019-05-27 17:46 ` Martin Blumenstingl
2019-05-27 18:00 ` Uwe Kleine-König
2019-05-27 18:00 ` Uwe Kleine-König
2019-05-27 18:00 ` Uwe Kleine-König
2019-05-28 18:04 ` Martin Blumenstingl [this message]
2019-05-28 18:04 ` Martin Blumenstingl
2019-05-28 18:04 ` Martin Blumenstingl
2019-05-25 18:11 ` [PATCH 05/14] pwm: meson: don't duplicate the polarity internally Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:26 ` Neil Armstrong
2019-05-27 12:26 ` Neil Armstrong
2019-05-27 12:26 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 06/14] pwm: meson: pass struct pwm_device to meson_pwm_calc() Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:27 ` Neil Armstrong
2019-05-27 12:27 ` Neil Armstrong
2019-05-27 12:27 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 07/14] pwm: meson: add the meson_pwm_channel data to struct meson_pwm Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:27 ` Neil Armstrong
2019-05-27 12:27 ` Neil Armstrong
2019-05-27 12:27 ` Neil Armstrong
2019-05-27 17:52 ` Martin Blumenstingl
2019-05-27 17:52 ` Martin Blumenstingl
2019-05-27 17:52 ` Martin Blumenstingl
2019-05-25 18:11 ` [PATCH 08/14] pwm: meson: add the per-channel register offsets and bits in a struct Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:28 ` Neil Armstrong
2019-05-27 12:28 ` Neil Armstrong
2019-05-27 12:28 ` Neil Armstrong
2019-05-27 17:57 ` Martin Blumenstingl
2019-05-27 17:57 ` Martin Blumenstingl
2019-05-27 17:57 ` Martin Blumenstingl
2019-05-28 8:11 ` Neil Armstrong
2019-05-28 8:11 ` Neil Armstrong
2019-05-28 8:11 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 09/14] pwm: meson: move pwm_set_chip_data() to meson_pwm_request() Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:30 ` Neil Armstrong
2019-05-27 12:30 ` Neil Armstrong
2019-05-27 12:30 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 10/14] pwm: meson: simplify the calculation of the pre-divider and count Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-26 19:41 ` Uwe Kleine-König
2019-05-26 19:41 ` Uwe Kleine-König
2019-05-26 19:41 ` Uwe Kleine-König
2019-05-26 19:41 ` Uwe Kleine-König
2019-05-27 12:37 ` Neil Armstrong
2019-05-27 12:37 ` Neil Armstrong
2019-05-27 12:37 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 11/14] pwm: meson: read the full hardware state in meson_pwm_get_state() Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:31 ` Neil Armstrong
2019-05-27 12:31 ` Neil Armstrong
2019-05-27 12:31 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 12/14] pwm: meson: don't cache struct pwm_state internally Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:31 ` Neil Armstrong
2019-05-27 12:31 ` Neil Armstrong
2019-05-27 12:31 ` Neil Armstrong
2019-05-25 18:11 ` [PATCH 13/14] pwm: meson: add support PWM_POLARITY_INVERSED when disabling Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:33 ` Neil Armstrong
2019-05-27 12:33 ` Neil Armstrong
2019-05-27 12:33 ` Neil Armstrong
2019-05-27 17:50 ` Martin Blumenstingl
2019-05-27 17:50 ` Martin Blumenstingl
2019-05-27 17:50 ` Martin Blumenstingl
2019-05-25 18:11 ` [PATCH 14/14] pwm: meson: add documentation to the driver Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-25 18:11 ` Martin Blumenstingl
2019-05-27 12:33 ` Neil Armstrong
2019-05-27 12:33 ` Neil Armstrong
2019-05-27 12:33 ` Neil Armstrong
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