From: Ansuel Smith <ansuelsmth@gmail.com>
To: "Marek Behún" <kabel@kernel.org>
Cc: Andrew Lunn <andrew@lunn.ch>,
Vivien Didelot <vivien.didelot@gmail.com>,
Florian Fainelli <f.fainelli@gmail.com>,
Vladimir Oltean <olteanv@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Rob Herring <robh+dt@kernel.org>,
Jonathan Corbet <corbet@lwn.net>, Pavel Machek <pavel@ucw.cz>,
John Crispin <john@phrozen.org>,
netdev@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
linux-leds@vger.kernel.org
Subject: Re: [RFC PATCH v3 2/8] leds: add function to configure hardware controlled LED
Date: Tue, 9 Nov 2021 15:22:53 +0100 [thread overview]
Message-ID: <YYqEPZpGmjNgFj0L@Ansuel-xps.localdomain> (raw)
In-Reply-To: <20211109040103.7b56bf82@thinkpad>
On Tue, Nov 09, 2021 at 04:01:03AM +0100, Marek Behún wrote:
> Hello Ansuel,
>
> On Tue, 9 Nov 2021 03:26:02 +0100
> Ansuel Smith <ansuelsmth@gmail.com> wrote:
>
> > Add hw_control_configure helper to configure how the LED should work in
> > hardware mode. The function require to support the particular trigger and
> > will use the passed flag to elaborate the data and apply the
> > correct configuration. This function will then be used by the trigger to
> > request and update hardware configuration.
> >
> > Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> > ---
> > Documentation/leds/leds-class.rst | 25 ++++++++++++++++++++
> > include/linux/leds.h | 39 +++++++++++++++++++++++++++++++
> > 2 files changed, 64 insertions(+)
> >
> > diff --git a/Documentation/leds/leds-class.rst b/Documentation/leds/leds-class.rst
> > index 645940b78d81..efd2f68c46a7 100644
> > --- a/Documentation/leds/leds-class.rst
> > +++ b/Documentation/leds/leds-class.rst
> > @@ -198,6 +198,31 @@ With HARDWARE_CONTROLLED blink_mode hw_control_status/start/stop is optional
> > and any software only trigger will reject activation as the LED supports only
> > hardware mode.
> >
> > +A trigger once he declared support for hardware controlled blinks, will use the function
> > +hw_control_configure() provided by the driver to check support for a particular blink mode.
> > +This function passes as the first argument (flag) a u32 flag.
> > +The second argument (cmd) of hw_control_configure() method can be used to do various
> > +operations for the specific blink mode. We currently support ENABLE, DISABLE, READ, ZERO
> > +and SUPPORTED to enable, disable, read the state of the blink mode, ask the LED
> > +driver if it does supports the specific blink mode and to reset any blink mode active.
> > +
> > +In ENABLE/DISABLE hw_control_configure() should configure the LED to enable/disable the
> > +requested blink mode (flag).
> > +In READ hw_control_configure() should return 0 or 1 based on the status of the requested
> > +blink mode (flag).
> > +In SUPPORTED hw_control_configure() should return 0 or 1 if the LED driver supports the
> > +requested blink mode (flags) or not.
> > +In ZERO hw_control_configure() should return 0 with success operation or error.
> > +
> > +The unsigned long flag is specific to the trigger and change across them. It's in the LED
> > +driver interest know how to elaborate this flag and to declare support for a
> > +particular trigger. For this exact reason explicit support for the specific
> > +trigger is mandatory or the driver returns -EOPNOTSUPP if asked to enter offload mode
> > +with a not supported trigger.
> > +If the driver returns -EOPNOTSUPP on hw_control_configure(), the trigger activation will
> > +fail as the driver doesn't support that specific offload trigger or doesn't know
> > +how to handle the provided flags.
> > +
> > Known Issues
> > ============
> >
> > diff --git a/include/linux/leds.h b/include/linux/leds.h
> > index cf0c6005c297..00bc4d6ed7ca 100644
> > --- a/include/linux/leds.h
> > +++ b/include/linux/leds.h
> > @@ -73,6 +73,16 @@ enum led_blink_modes {
> > SOFTWARE_HARDWARE_CONTROLLED,
> > };
> >
> > +#ifdef CONFIG_LEDS_HARDWARE_CONTROL
> > +enum blink_mode_cmd {
> > + BLINK_MODE_ENABLE, /* Enable the hardware blink mode */
> > + BLINK_MODE_DISABLE, /* Disable the hardware blink mode */
> > + BLINK_MODE_READ, /* Read the status of the hardware blink mode */
> > + BLINK_MODE_SUPPORTED, /* Ask the driver if the hardware blink mode is supported */
> > + BLINK_MODE_ZERO, /* Disable any hardware blink active */
> > +};
> > +#endif
>
> this is a strange proposal for the API.
>
> Anyway, led_classdev already has the blink_set() method, which is documented as
> /*
> * Activate hardware accelerated blink, delays are in milliseconds
> * and if both are zero then a sensible default should be chosen.
> * The call should adjust the timings in that case and if it can't
> * match the values specified exactly.
> * Deactivate blinking again when the brightness is set to LED_OFF
> * via the brightness_set() callback.
> */
> int (*blink_set)(struct led_classdev *led_cdev,
> unsigned long *delay_on,
> unsigned long *delay_off);
>
> So we already have a method to set hardware blkinking, we don't need
> another one.
>
> Marek
But that is about hardware blink, not a LED controlled by hardware based
on some rules/modes.
Doesn't really match the use for the hardware control.
Blink_set makes the LED blink contantly at the declared delay.
The blink_mode_cmd are used to request stuff to a LED in hardware mode.
Doesn't seem correct to change/enhance the blink_set function with
something that would do something completely different.
--
Ansuel
next prev parent reply other threads:[~2021-11-09 14:22 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-09 2:26 [RFC PATCH v3 0/8] Adds support for PHY LEDs with offload triggers Ansuel Smith
2021-11-09 2:26 ` [RFC PATCH v3 1/8] leds: add support for hardware driven LEDs Ansuel Smith
2021-11-09 6:16 ` Randy Dunlap
2021-11-09 20:34 ` Andrew Lunn
2021-11-09 20:40 ` Ansuel Smith
2021-11-09 2:26 ` [RFC PATCH v3 2/8] leds: add function to configure hardware controlled LED Ansuel Smith
2021-11-09 3:01 ` Marek Behún
2021-11-09 14:22 ` Ansuel Smith [this message]
2021-11-09 20:49 ` Andrew Lunn
2021-11-10 19:51 ` Ansuel Smith
2021-11-10 22:24 ` Andrew Lunn
2021-11-09 22:18 ` Marek Behún
2021-11-09 6:12 ` Randy Dunlap
2021-11-09 2:26 ` [RFC PATCH v3 3/8] leds: trigger: netdev: drop NETDEV_LED_MODE_LINKUP from mode Ansuel Smith
2021-11-09 3:02 ` Marek Behún
2021-11-09 14:24 ` Ansuel Smith
2021-11-09 20:53 ` Andrew Lunn
2021-11-09 2:26 ` [RFC PATCH v3 4/8] leds: trigger: netdev: rename and expose NETDEV trigger enum modes Ansuel Smith
2021-11-09 20:58 ` Andrew Lunn
2021-11-10 19:57 ` Ansuel Smith
2021-11-10 22:29 ` Andrew Lunn
2021-11-09 2:26 ` [RFC PATCH v3 5/8] leds: trigger: netdev: add hardware control support Ansuel Smith
2021-11-09 3:12 ` Marek Behún
2021-11-09 15:02 ` Ansuel Smith
2021-11-09 2:26 ` [RFC PATCH v3 6/8] leds: trigger: add hardware-phy-activity trigger Ansuel Smith
2021-11-09 3:25 ` Marek Behún
2021-11-09 21:09 ` Andrew Lunn
2021-11-10 20:04 ` Ansuel Smith
2021-11-10 22:32 ` Andrew Lunn
2021-11-09 6:02 ` Randy Dunlap
2021-11-09 15:06 ` Ansuel Smith
2021-11-09 21:17 ` Andrew Lunn
2021-11-09 21:28 ` Andrew Lunn
2021-11-09 2:26 ` [RFC PATCH v3 7/8] net: dsa: qca8k: add LEDs support Ansuel Smith
2021-11-09 6:03 ` Randy Dunlap
2021-11-09 21:22 ` Andrew Lunn
2021-11-09 2:26 ` [RFC PATCH v3 8/8] dt-bindings: net: dsa: qca8k: add LEDs definition example Ansuel Smith
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=YYqEPZpGmjNgFj0L@Ansuel-xps.localdomain \
--to=ansuelsmth@gmail.com \
--cc=andrew@lunn.ch \
--cc=corbet@lwn.net \
--cc=davem@davemloft.net \
--cc=devicetree@vger.kernel.org \
--cc=f.fainelli@gmail.com \
--cc=john@phrozen.org \
--cc=kabel@kernel.org \
--cc=kuba@kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-leds@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=olteanv@gmail.com \
--cc=pavel@ucw.cz \
--cc=robh+dt@kernel.org \
--cc=vivien.didelot@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).