From: Stephen Warren <swarren@wwwdotorg.org>
To: Bart Tanghe <bart.tanghe@thomasmore.be>, thierry.reding@gmail.com
Cc: matt.porter@linaro.org, linux-kernel@vger.kernel.org,
linux-pwm@vger.kernel.org, linux-rpi-kernel@lists.infradead.org
Subject: Re: [PATCH v6]pwm: add BCM2835 PWM driver
Date: Tue, 07 Oct 2014 08:35:51 -0700 [thread overview]
Message-ID: <54340857.9000409@wwwdotorg.org> (raw)
In-Reply-To: <1412690665-15416-1-git-send-email-bart.tanghe@thomasmore.be>
On 10/07/2014 07:04 AM, Bart Tanghe wrote:
> Add pwm driver for Broadcom BCM2835 processor (Raspberry Pi)
Just a few nits below,
> diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c
> +#define PWM_CONTROL_MASK 0xff
> +#define PWM_MODE 0x80 /* set timer in pwm mode */
> +#define DEFAULT 0xff /* set timer in default mode */
BTW, it'd be nice to say default *what*. Perhaps DEFAULT_PWM_MODE?
> +static int bcm2835_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
> +{
> + struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
> + u32 value;
> +
> + value = readl(pc->base);
> + value &= ~(PWM_CONTROL_MASK << PWM_CONTROL_STRIDE * pwm->hwpwm);
> + value |= (PWM_MODE << (PWM_CONTROL_STRIDE * pwm->hwpwm));
Presence/absence of brackets around the STRIDE*pwm calculation is still
inconsistent here, and in other places.
> +static void bcm2835_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
> +{
> + struct bcm2835_pwm *pc = to_bcm2835_pwm(chip);
> + u32 value;
> +
> + value = readl(pc->base);
> + value &= (~DEFAULT << (PWM_CONTROL_STRIDE * pwm->hwpwm));
Why clear the "DEFAULT" bits here; why not use PWM_CONTROL_MASK?
prev parent reply other threads:[~2014-10-07 15:35 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-07 14:04 [PATCH v6]pwm: add BCM2835 PWM driver Bart Tanghe
2014-10-07 14:14 ` Marc Kleine-Budde
2014-10-07 15:35 ` Stephen Warren [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=54340857.9000409@wwwdotorg.org \
--to=swarren@wwwdotorg.org \
--cc=bart.tanghe@thomasmore.be \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pwm@vger.kernel.org \
--cc=linux-rpi-kernel@lists.infradead.org \
--cc=matt.porter@linaro.org \
--cc=thierry.reding@gmail.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).