From: "Nuno Sá" <noname.nuno@gmail.com>
To: "David Lechner" <dlechner@baylibre.com>,
"Uwe Kleine-König" <ukleinek@kernel.org>
Cc: "Michael Hennerich" <michael.hennerich@analog.com>,
"Nuno Sá" <nuno.sa@analog.com>,
"Trevor Gamblin" <tgamblin@baylibre.com>,
linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] pwm: axi-pwmgen: always enable FORCE_ALIGN
Date: Thu, 10 Oct 2024 10:33:20 +0200 [thread overview]
Message-ID: <57169283416bf7902523891ba03d1f878772ffe5.camel@gmail.com> (raw)
In-Reply-To: <20241009-pwm-axi-pwmgen-enable-force_align-v1-0-5d6ad8cbf5b4@baylibre.com>
On Wed, 2024-10-09 at 16:11 -0500, David Lechner wrote:
> When using the axi-pwmgen as a trigger for ADCs, we've found that the
> default behavior of the PWMGEN IP block is not ideal. The default
> behavior is to wait for the period of all PWM outputs to run out before
> applying any new settings. But there isn't a way to block until this
> happens (and even if there was, it could take a long time). So the
> pwm apply function returns before the new settings are actually applied.
>
> This makes certain use cases impossible. For example, to use the PWM
> like a GPIO to create a single pulse on and off to trigger a single ADC
> conversion.
>
> The AXI PWMGEN has a FORCE_ALIGN configuration option that changes the
> behavior so that any new output settings (period, duty cycle, etc.) are
> applied immediately. This can cause glitches in the output, but makes
> the PWM actually useable for most applications.
>
> Also, there was a naming conflict with register names, so there is a
> preliminary cleanup patch to sort that out.
>
> ---
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
> David Lechner (2):
> pwm: axi-pwmgen: rename 0x10 register
> pwm: axi-pwmgen: enable FORCE_ALIGN by default
>
> drivers/pwm/pwm-axi-pwmgen.c | 24 ++++++++++++++++++------
> 1 file changed, 18 insertions(+), 6 deletions(-)
> ---
> base-commit: ff25451372ee1aa4c4f4401dc96516782a00dd4d
> change-id: 20241009-pwm-axi-pwmgen-enable-force_align-cfb403da4612
>
> Best regards,
next prev parent reply other threads:[~2024-10-10 8:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-09 21:11 David Lechner
2024-10-09 21:11 ` [PATCH 1/2] pwm: axi-pwmgen: rename 0x10 register David Lechner
2024-10-09 21:11 ` [PATCH 2/2] pwm: axi-pwmgen: enable FORCE_ALIGN by default David Lechner
2024-10-10 8:33 ` Nuno Sá [this message]
2024-10-11 9:51 ` [PATCH 0/2] pwm: axi-pwmgen: always enable FORCE_ALIGN Uwe Kleine-König
2024-10-11 10:14 ` Nuno Sá
2024-10-11 9:53 ` Uwe Kleine-König
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