From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Claudiu Beznea <claudiu.beznea@microchip.com>
Cc: mturquette@linaro.org, bbrezillon@kernel.org, sboyd@kernel.org,
mturquette@baylibre.com, linux-kernel@vger.kernel.org,
ludovic.desroches@microchip.com, linux-clk@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] clk: at91: clk-main: update key before writing AT91_CKGR_MOR
Date: Tue, 4 Aug 2020 18:00:28 +0200 [thread overview]
Message-ID: <20200804160028.GD10725@piout.net> (raw)
In-Reply-To: <1596099803-1393-1-git-send-email-claudiu.beznea@microchip.com>
On 30/07/2020 12:03:23+0300, Claudiu Beznea wrote:
> SAMA5D2 datasheet specifies on chapter 33.22.8 (PMC Clock Generator
> Main Oscillator Register) that writing any value other than
> 0x37 on KEY field aborts the write operation. Use the key when
> selecting main clock parent.
>
> Fixes: 27cb1c2083373 ("clk: at91: rework main clk implementation")
> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
> ---
> drivers/clk/at91/clk-main.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c
> index 5c83e899084f..cfae2f59df66 100644
> --- a/drivers/clk/at91/clk-main.c
> +++ b/drivers/clk/at91/clk-main.c
> @@ -437,12 +437,17 @@ static int clk_sam9x5_main_set_parent(struct clk_hw *hw, u8 index)
> return -EINVAL;
>
> regmap_read(regmap, AT91_CKGR_MOR, &tmp);
> - tmp &= ~MOR_KEY_MASK;
>
> if (index && !(tmp & AT91_PMC_MOSCSEL))
> - regmap_write(regmap, AT91_CKGR_MOR, tmp | AT91_PMC_MOSCSEL);
> + tmp = AT91_PMC_MOSCSEL;
> else if (!index && (tmp & AT91_PMC_MOSCSEL))
> - regmap_write(regmap, AT91_CKGR_MOR, tmp & ~AT91_PMC_MOSCSEL);
> + tmp = 0;
> + else
> + return 0;
> +
> + regmap_update_bits(regmap, AT91_CKGR_MOR,
> + AT91_PMC_MOSCSEL | MOR_KEY_MASK,
> + tmp | AT91_PMC_KEY);
>
> while (!clk_sam9x5_main_ready(regmap))
> cpu_relax();
> --
> 2.7.4
>
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
prev parent reply other threads:[~2020-08-04 16:02 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-30 9:03 [PATCH] clk: at91: clk-main: update key before writing AT91_CKGR_MOR Claudiu Beznea
2020-08-04 16:00 ` Alexandre Belloni [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200804160028.GD10725@piout.net \
--to=alexandre.belloni@bootlin.com \
--cc=bbrezillon@kernel.org \
--cc=claudiu.beznea@microchip.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-clk@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ludovic.desroches@microchip.com \
--cc=mturquette@baylibre.com \
--cc=mturquette@linaro.org \
--cc=sboyd@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).