From: guenter.roeck@ericsson•com (Guenter Roeck)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/2] hwmon: add generic GPIO fan driver
Date: Tue, 19 Oct 2010 08:15:12 -0700 [thread overview]
Message-ID: <20101019151512.GB13908@ericsson.com> (raw)
In-Reply-To: <20101019083656.GE29120@kw.sim.vm.gnt>
Hi Simon,
On Tue, Oct 19, 2010 at 04:36:56AM -0400, Simon Guinot wrote:
[ ... ]
> /* Designed for fan 40x40x16: ADDA AD0412LB-D50 6000rpm at 12v */
> static struct gpio_fan_speed netspace_max_v2_fan_speed[] = {
> { 0, 0 },
> { 1500, 15 },
> { 1700, 14 },
> { 1800, 13 },
> { 2100, 12 },
> { 3100, 11 },
> { 3300, 10 },
> { 4300, 9 },
> { 5500, 8 },
> };
>
> The function rpm_speed(index) is really not linear. I am not sure about
> the resulting behaviour when this will be used by a userland fan control
> process...
>
> If the pwm interface must be exported, I think we have to respect the
> fan speed array. But as you said, maybe the work is rather on the
> fancontrol script side.
>
Not sure if there is an expectation that the mapping pwm->speed has
to be linear. One might as well argue that steps should be equally
far apart to ensure that results are better predictable.
> As a first step, we could keep the heavy pwm interface. Once the
> fancontrol script (or something else) will be able to handle the rpm
> attributes, we will drop the pwm compatibility.
> Simply remove the gpio-fan pwm interface seems a good option too...
>
I think we should keep the pwm interface after all. Changing fancontrol
is a possibility, but the change would take a while to make it upstream.
As for the actual code, I would prefer the simpler implementation, but I am willing
to go with the complex one if you feel wtrongly about it. Only thing I would ask you
to do is to add an explanation of what is done and why.
Reminds me - you'll also have to provide Documentation/hwmon/gpio-fan.
Thanks,
Guenter
next prev parent reply other threads:[~2010-10-19 15:15 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-22 10:54 [PATCH 4/5] hwmon: DNS323 rev C1 fan support Benjamin Herrenschmidt
2010-05-22 11:00 ` Benjamin Herrenschmidt
2010-10-13 11:59 ` Simon Guinot
2010-10-13 16:34 ` [lm-sensors] " Guenter Roeck
2010-10-17 15:40 ` Simon Guinot
2010-10-17 15:50 ` [PATCH 1/2] hwmon: add generic GPIO fan driver Simon Guinot
2010-10-17 15:50 ` [PATCH 2/2] [ARM] Kirkwood: add fan support for Network Space Max v2 Simon Guinot
2010-10-22 1:53 ` Guenter Roeck
2010-10-22 2:08 ` Nicolas Pitre
2010-10-22 4:30 ` Guenter Roeck
2010-10-22 9:29 ` [PATCH] " Simon Guinot
2010-10-22 9:59 ` Guenter Roeck
2010-10-22 8:27 ` [PATCH 2/2] " Simon Guinot
2010-10-22 9:58 ` Guenter Roeck
2010-10-22 18:39 ` Guenter Roeck
2010-10-22 18:50 ` Nicolas Pitre
2010-10-18 16:08 ` [PATCH 1/2] hwmon: add generic GPIO fan driver Guenter Roeck
2010-10-18 18:00 ` Chris Moore
2010-10-18 18:35 ` Guenter Roeck
2010-10-18 20:36 ` Simon Guinot
2010-10-18 20:50 ` Guenter Roeck
2010-10-19 11:46 ` Simon Guinot
2010-10-19 14:52 ` Guenter Roeck
2010-10-19 6:52 ` Guenter Roeck
2010-10-19 8:36 ` Simon Guinot
2010-10-19 15:15 ` Guenter Roeck [this message]
2010-10-19 19:30 ` Simon Guinot
2010-10-21 20:07 ` Simon Guinot
2010-10-21 20:26 ` Guenter Roeck
2010-10-19 22:03 ` Guenter Roeck
2010-10-20 0:19 ` Simon Guinot
2010-10-20 0:50 ` Guenter Roeck
2010-10-20 7:59 ` Simon Guinot
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