From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Simon Horman <horms+renesas@verge.net.au>
Cc: Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Magnus Damm <magnus.damm@gmail.com>
Subject: Re: [PATCH v3 2/6] clk: renesas: rcar-gen3: Add Z2 clock divider support
Date: Tue, 10 Oct 2017 08:56:35 +0200 [thread overview]
Message-ID: <CAMuHMdVg4sFkZvqfv0SZkefSy1UN=eBtwQrii7OtbYqyjfmC=Q@mail.gmail.com> (raw)
In-Reply-To: <CAMuHMdWpbZ5r5s2+29rLBcPABUaN0BBXEZreryoCSriDcqqdkQ@mail.gmail.com>
Hi Simon,
On Mon, Oct 9, 2017 at 10:02 AM, Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> On Thu, Oct 5, 2017 at 3:23 PM, Simon Horman <horms+renesas@verge.net.au> wrote:
>> From: Takeshi Kihara <takeshi.kihara.df@renesas.com>
>>
>> This patch adds Z2 clock divider support for R-Car Gen3 SoC.
>>
>> Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
>> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
>> ---
>> v2 [Simon Horman]
>> * Consolidate Z and Z2 clock ops
>> * Allow setting of Z2 clock
>
> Thanks for the update!
>
>> --- a/drivers/clk/renesas/rcar-gen3-cpg.c
>> +++ b/drivers/clk/renesas/rcar-gen3-cpg.c
>
>> @@ -88,8 +90,8 @@ static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate,
>> if (clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK)
>> return -EBUSY;
>>
>> - val = clk_readl(zclk->reg) & ~CPG_FRQCRC_ZFC_MASK;
>> - val |= FIELD_PREP(CPG_FRQCRC_ZFC_MASK, 32 - mult);
>> + val = clk_readl(zclk->reg) & ~zclk->mask;
>> + val |= ((32 - mult) << __bf_shf(zclk->mask)) & zclk->mask;
>
> Any special reason you're now open coding FIELD_PREP()?
Now I know: to circumvent the
BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask), ...) in
__BF_FIELD_CHECK(), called from FIELD_PREP().
Given <linux/bitfield.h> is intended to work with constant masks
only, I think it's best to not use it, and replace __bf_shf() by __ffs().
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Oops, looks like you forgot to replace CPG_FRQCRC_ZFC_MASK in
cpg_z_clk_recalc_rate() by zclk->mask.
Sorry for missing that.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
WARNING: multiple messages have this Message-ID (diff)
From: geert@linux-m68k.org (Geert Uytterhoeven)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 2/6] clk: renesas: rcar-gen3: Add Z2 clock divider support
Date: Tue, 10 Oct 2017 08:56:35 +0200 [thread overview]
Message-ID: <CAMuHMdVg4sFkZvqfv0SZkefSy1UN=eBtwQrii7OtbYqyjfmC=Q@mail.gmail.com> (raw)
In-Reply-To: <CAMuHMdWpbZ5r5s2+29rLBcPABUaN0BBXEZreryoCSriDcqqdkQ@mail.gmail.com>
Hi Simon,
On Mon, Oct 9, 2017 at 10:02 AM, Geert Uytterhoeven
<geert@linux-m68k.org> wrote:
> On Thu, Oct 5, 2017 at 3:23 PM, Simon Horman <horms+renesas@verge.net.au> wrote:
>> From: Takeshi Kihara <takeshi.kihara.df@renesas.com>
>>
>> This patch adds Z2 clock divider support for R-Car Gen3 SoC.
>>
>> Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
>> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
>> ---
>> v2 [Simon Horman]
>> * Consolidate Z and Z2 clock ops
>> * Allow setting of Z2 clock
>
> Thanks for the update!
>
>> --- a/drivers/clk/renesas/rcar-gen3-cpg.c
>> +++ b/drivers/clk/renesas/rcar-gen3-cpg.c
>
>> @@ -88,8 +90,8 @@ static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate,
>> if (clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK)
>> return -EBUSY;
>>
>> - val = clk_readl(zclk->reg) & ~CPG_FRQCRC_ZFC_MASK;
>> - val |= FIELD_PREP(CPG_FRQCRC_ZFC_MASK, 32 - mult);
>> + val = clk_readl(zclk->reg) & ~zclk->mask;
>> + val |= ((32 - mult) << __bf_shf(zclk->mask)) & zclk->mask;
>
> Any special reason you're now open coding FIELD_PREP()?
Now I know: to circumvent the
BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask), ...) in
__BF_FIELD_CHECK(), called from FIELD_PREP().
Given <linux/bitfield.h> is intended to work with constant masks
only, I think it's best to not use it, and replace __bf_shf() by __ffs().
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Oops, looks like you forgot to replace CPG_FRQCRC_ZFC_MASK in
cpg_z_clk_recalc_rate() by zclk->mask.
Sorry for missing that.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
next prev parent reply other threads:[~2017-10-10 6:56 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-05 13:23 [PATCH v3 0/6] clk: renesas: r8a779[56]: Add Z and Z2 clock support Simon Horman
2017-10-05 13:23 ` Simon Horman
2017-10-05 13:23 ` [PATCH v3 1/6] clk: renesas: rcar-gen3: Add Z clock divider support Simon Horman
2017-10-05 13:23 ` Simon Horman
2017-10-09 8:02 ` Geert Uytterhoeven
2017-10-09 8:02 ` Geert Uytterhoeven
2017-10-10 7:23 ` Simon Horman
2017-10-10 7:23 ` Simon Horman
2017-10-05 13:23 ` [PATCH v3 2/6] clk: renesas: rcar-gen3: Add Z2 " Simon Horman
2017-10-05 13:23 ` Simon Horman
2017-10-09 8:02 ` Geert Uytterhoeven
2017-10-09 8:02 ` Geert Uytterhoeven
2017-10-10 6:56 ` Geert Uytterhoeven [this message]
2017-10-10 6:56 ` Geert Uytterhoeven
2017-10-10 7:22 ` Simon Horman
2017-10-10 7:22 ` Simon Horman
2017-10-05 13:23 ` [PATCH v3 3/6] clk: renesas: r8a7795: Add Z clock Simon Horman
2017-10-05 13:23 ` Simon Horman
2017-10-05 13:23 ` [PATCH v3 4/6] clk: renesas: r8a7795: Add Z2 clock Simon Horman
2017-10-05 13:23 ` Simon Horman
2017-10-05 13:23 ` [PATCH v3 5/6] clk: renesas: r8a7796: Add Z clock Simon Horman
2017-10-05 13:23 ` Simon Horman
2017-10-05 13:23 ` [PATCH v3 6/6] clk: renesas: r8a7796: Add Z2 clock Simon Horman
2017-10-05 13:23 ` Simon Horman
2017-10-09 13:05 ` [PATCH v3 0/6] clk: renesas: r8a779[56]: Add Z and Z2 clock support Geert Uytterhoeven
2017-10-09 13:05 ` Geert Uytterhoeven
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