From: Charles Keepax <ckeepax@opensource.cirrus.com>
To: chen liu <chen.liu.opensource@gmail.com>
Cc: <lgirdwood@gmail.com>, <broonie@kernel.org>, <perex@perex.cz>,
<tiwai@suse.com>, <shengjiu.wang@freescale.com>,
<linux-kernel@vger.kernel.org>, <daniel.baluta@nxp.com>,
<patches@opensource.wolfsonmicro.com>,
<alsa-devel@alsa-project.org>
Subject: Re: [PATCH v2] ASOC: wm8960: Add multiple MCLK frequency support
Date: Mon, 18 Dec 2017 09:31:22 +0000 [thread overview]
Message-ID: <20171218093122.mgghz4mkxtvix6uu@localhost.localdomain> (raw)
In-Reply-To: <CACJSzi0Kuknj6xFpambi87a1cXecGdfNGQ7PpgywwZV=9_U1yA@mail.gmail.com>
On Fri, Dec 15, 2017 at 09:07:15PM +0800, chen liu wrote:
> 2017-12-15 0:19 GMT+08:00 Charles Keepax <ckeepax@opensource.cirrus.com>:
> > On Wed, Dec 13, 2017 at 08:37:30PM +0800, Chen.Liu wrote:
> When the MCLK clock frequency cannot meet the SYSCLK clock
> frequency of the wm8960 codec,we must use the PLL divider to
> generate the clock frequency.
>
> For what you are talking about setting the SYSCLK clock frequency
> automatically and manually,the difference is that one uses the PLL
> divider to generate the SYSCLK clock frequency and the other one
> provides the SYSCLK clock frequency directly through the MCLK.
>
> Although the driver already supports setting the SYSCLK_DIV register,
> it can only be set to 1,thus causing the codec to not support multiple
> MCLK clock frequency.(For more information, please see the wm8960
> codec manual)
>
> The important purpose of this patch is to support multiple MCLK
> clock frequency.
Sorry I think I am not following something here, could you be a
bit more specific, especially about why the automatic approach
doesn't meet your needs.
As far as I can see this will let you set the SYSCLKDIV using the
manual method and it can be easily set to either 1 or 2:
static int wm8960_set_dai_clkdiv(struct snd_soc_dai *codec_dai,
...
switch (div_id) {
case WM8960_SYSCLKDIV:
reg = snd_soc_read(codec, WM8960_CLOCK1) & 0x1f9;
snd_soc_write(codec, WM8960_CLOCK1, reg | div);
break;
...
And as for the automatic method:
static int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in,
...
for (i = 0; i < ARRAY_SIZE(sysclk_divs); ++i) {
if (sysclk_divs[i] == -1) continue;
...
This will iterate through all the sysclk_dividers and pick one
that is appropriate either 1 or 2. So in what way does the
automatic method not support a SYSCLK_DIV of 2?
Thanks,
Charles
next prev parent reply other threads:[~2017-12-18 9:32 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-13 12:37 [PATCH v2] ASOC: wm8960: Add multiple MCLK frequency support Chen.Liu
2017-12-14 11:56 ` Charles Keepax
2017-12-14 15:31 ` Mark Brown
2017-12-14 15:51 ` Charles Keepax
2017-12-14 16:45 ` Mark Brown
2017-12-14 16:19 ` Charles Keepax
[not found] ` <CACJSzi0Kuknj6xFpambi87a1cXecGdfNGQ7PpgywwZV=9_U1yA@mail.gmail.com>
2017-12-18 9:31 ` Charles Keepax [this message]
[not found] ` <CACJSzi13ZdOjvz1A2YFbE3z0nUPjeC7i5Dh+ZTnsQH55ON=YMA@mail.gmail.com>
2017-12-18 11:55 ` Charles Keepax
[not found] ` <CACJSzi0hbv2p_6dXkp2AFwyYVzmU6_H56LgJxY70_ZKn2y=aUw@mail.gmail.com>
2017-12-21 16:48 ` Charles Keepax
2017-12-22 10:40 ` chen liu
2017-12-29 11:05 ` Charles Keepax
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=20171218093122.mgghz4mkxtvix6uu@localhost.localdomain \
--to=ckeepax@opensource.cirrus.com \
--cc=alsa-devel@alsa-project.org \
--cc=broonie@kernel.org \
--cc=chen.liu.opensource@gmail.com \
--cc=daniel.baluta@nxp.com \
--cc=lgirdwood@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=patches@opensource.wolfsonmicro.com \
--cc=perex@perex.cz \
--cc=shengjiu.wang@freescale.com \
--cc=tiwai@suse.com \
/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).