Add LED driven by multiple gpio.

PATCH In review Dmitry Bondar 4 participants 7 messages Apr 25, 2016 – Apr 29, 2016

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Dmitry Bondar

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2016-04-25 08:29 UTC #0 lore raw

PATCH 1/1 Add LED driven by multiple gpio.

Hello, on our board we have one LED with 2 gpio connected to it:
- when gpio0 is on and gpio1 on - LED is orange.
- when gpio0 is on and gpio1 off - LED is green.
- when gpio0 is off and gpio1 on - LED is red.
- when gpio0 is off and gpio1 off - LED is off.
We want use led_trigger (nand-disk) on this LED.
Below patch which we use for get one LED on 2 gpios. Can be this in mainline, or may be exist other - better way?

Signature · 2 lines

Dmitry Bondar, 
simicon.com

Quoted 1 line

From 27f61d2bf3264f1434c0e568c5adb82fafc591b1 Mon Sep 17 00:00:00 2001

From: Dmitry Bondar <[email protected]>
Date: Fri, 22 Apr 2016 18:33:44 +0300
Subject: [PATCH 0/2] Add LED driven by multiple gpio

Dmitry Bondar (2):
add multiple gpio led(mgpio-led) description to device tree add multiple gpio led(mgpio-led) driver

 .../devicetree/bindings/leds/leds-mgpio.txt        |   31 ++++
 drivers/leds/Kconfig                               |    8 +
 drivers/leds/Makefile                              |    1 +
 drivers/leds/leds-mgpio.c                          |  191 ++++++++++++++++++++
 4 files changed, 231 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-mgpio.txt
 create mode 100644 drivers/leds/leds-mgpio.c

Signature · 1 line

1.7.10.4

Quoted 1 line

From 359cf82ccd8ca100b4330596843af17fbaa85a9e Mon Sep 17 00:00:00 2001

From: Dmitry Bondar <[email protected]>
Date: Fri, 22 Apr 2016 17:46:33 +0300
Subject: [PATCH 1/2] Add LED driven by multiple gpio
led(mgpio-led) description to
device tree

---
 .../devicetree/bindings/leds/leds-mgpio.txt        |   31 ++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-mgpio.txt

Documentation/devicetree/bindings/leds/leds-mgpio.txt new file +31 -0

new file mode 100644
index 0000000..135d810
@@ -0,0 +1,31 @@
+LED connected to multiple GPIO lines
+For example red/green/orange led with to 2 gpio connectd to it.
+
+Required properties:
+- compatible : should be "mgpio-led".
+- gpios :  Should specify the LED's GPIOs, see "gpios property" in
+  Documentation/devicetree/bindings/gpio/gpio.txt.  Active low LEDs should be
+  indicated using flags in the GPIO specifier.
+- color_names: list of colors
+- color_vals: list of gpio values for each color
+  in example below for red led gpio 23 must be 0 and gpio 8 must be 1
+
+Optional properties:
+- label :
+  see Documentation/devicetree/bindings/leds/common.txt
+- linux,default-trigger :
+  see Documentation/devicetree/bindings/leds/common.txt
+- default-color
+  string from color-names
+Examples:
+
+led_uplink{
+        compatible = "simicon,mgpio-led";
+        label = "uplink";
+        gpios = <&portb 23 GPIO_ACTIVE_HIGH>, <&portb 8 GPIO_ACTIVE_HIGH>;
+        color_vals =  <1 1>, <0 1>, <1 0>;
+        color_names = "orange", "red", "green";
+        default-color = "green";
+        linux,default-trigger = "heartbeat";
+};
+

Signature · 1 line

1.7.10.4

Quoted 1 line

From 27f61d2bf3264f1434c0e568c5adb82fafc591b1 Mon Sep 17 00:00:00 2001

From: Dmitry Bondar <[email protected]>
Date: Fri, 22 Apr 2016 17:50:04 +0300
Subject: [PATCH 2/2] Add LED driven by multiple gpio
led(mgpio-led) driver

---
 drivers/leds/Kconfig      |    8 ++
 drivers/leds/Makefile     |    1 +
 drivers/leds/leds-mgpio.c |  191 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 200 insertions(+)
 create mode 100644 drivers/leds/leds-mgpio.c

drivers/leds/Kconfig +8 -0

index 2251478..33ce940 100644
@@ -616,6 +616,14 @@ config LEDS_VERSATILE
 	  This option enabled support for the LEDs on the ARM Versatile
 	  and RealView boards. Say Y to enabled these.
 
+config LEDS_MGPIO
+	tristate "LED driven by multiple gpio"
+	depends on LEDS_CLASS
+	depends on GPIOLIB || COMPILE_TEST
+	help
+	  This option enables support for the LEDs connected to
+	  multiple GPIO outputs.
+
 comment "LED Triggers"
 source "drivers/leds/trigger/Kconfig"

drivers/leds/Makefile +1 -0

index cb2013d..e6189e2 100644
@@ -67,6 +67,7 @@ obj-$(CONFIG_LEDS_KTD2692)		+= leds-ktd2692.o
 obj-$(CONFIG_LEDS_POWERNV)		+= leds-powernv.o
 obj-$(CONFIG_LEDS_SEAD3)		+= leds-sead3.o
 obj-$(CONFIG_LEDS_IS31FL32XX)		+= leds-is31fl32xx.o
+obj-$(CONFIG_LEDS_MGPIO)		+= leds-mgpio.c
 
 # LED SPI Drivers
 obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o

drivers/leds/leds-mgpio.c new file +191 -0

191 lines not on this page · raw message

Signature · 1 line

1.7.10.4

Jacek Anaszewski

2016-04-25 09:23 UTC #1 lore raw

Hi Dmitry,

First of all, please don't send patches as attachments but use git send-email on each of them.

Regarding the driver - if the LEDs are not driven by some LED controller device, then this patch fits better for GPIO subsystem IMO.

Quoted 9 lines · Dmitry Bondar

Hello, on our board we have one LED with 2 gpio connected to it:
- when gpio0 is on and gpio1 on - LED is orange.
- when gpio0 is on and gpio1 off - LED is green.
- when gpio0 is off and gpio1 on - LED is red.
- when gpio0 is off and gpio1 off - LED is off.
We want use led_trigger (nand-disk) on this LED.
Below patch which we use for get one LED on 2 gpios. Can be this in mainline, or may be exist other - better way?

Signature · 2 lines

Best regards,
Jacek Anaszewski

Jacek Anaszewski

2016-04-27 06:56 UTC #2 lore raw

Quoted 7 lines · Jacek Anaszewski

Hi Dmitry,
First of all, please don't send patches as attachments but use git send-email on each of them.
Regarding the driver - if the LEDs are not driven by some LED controller device, then this patch fits better for GPIO subsystem IMO.

Of course the driver should register LED class device anyway, but the main question is how the GPIO logic is implemented. Is it some publicly available chip or a circuit composed of discrete elements?

Quoted 12 lines · Dmitry Bondar

Quoted 9 lines
Hello, on our board we have one LED with 2 gpio connected to it:
- when gpio0 is on and gpio1 on - LED is orange.
- when gpio0 is on and gpio1 off - LED is green.
- when gpio0 is off and gpio1 on - LED is red.
- when gpio0 is off and gpio1 off - LED is off.
We want use led_trigger (nand-disk) on this LED.
Below patch which we use for get one LED on 2 gpios. Can be this in mainline, or may be exist other - better way?

Signature · 2 lines

Best regards,
Jacek Anaszewski

David Rivshin (Allworx)

2016-04-26 20:27 UTC #3 lore raw

In reply to Dmitry Bondar

Quoted 9 lines · On Mon, 25 Apr 2016 11:14:38 +0300 Dmitry Bondar <[email protected]> wrote:

Hello, on our board we have one LED with 2 gpio connected to it:
- when gpio0 is on and gpio1 on - LED is orange.
- when gpio0 is on and gpio1 off - LED is green.
- when gpio0 is off and gpio1 on - LED is red.
- when gpio0 is off and gpio1 off - LED is off.
We want use led_trigger (nand-disk) on this LED.
Below patch which we use for get one LED on 2 gpios. Can be this in mainline, or may be exist other - better way?

It sounds like what you have is two independent GPIO controlled LEDs:
one green and the other red (even if they are part of the same IC). Given the current infrastructure, I have modeled such cases as two separate LEDs in the devicetree, named <device>:green:<function> and <device>:red:<function>. Userspace is then responsible for controlling them appropriately to get the desired color.

Unless I'm mistaken, in your case (nand-disk) there are blinking combinations you wouldn't be able to achieve this way, but there are a number you can do:
- off/green: green:nand-disk red:off
- off/red: green:off red:nand-disk
- off/orange: green:nand-disk red:nand-disk
- green/orange: green:on red:nand-disk
- red/orange: green:nand-disk red:on
The other cases (e.g. green/red) would need an inverted nand-disk trigger (on while inactive, off while active).

I'm hoping that if the RGB LED framework comes to fruition, that there will be some way to combine arbitrary single-color LED devices into a logical RGB LED. I suspect there are many boards that would find it useful to expose a single RGB LED to userspace (and triggers), as opposed to separate R, G, and B LEDs.

Jacek Anaszewski

2016-04-29 12:42 UTC #4 lore raw

Hi David,

Quoted 31 lines · David Rivshin (Allworx)

Quoted 9 lines · On Mon, 25 Apr 2016 11:14:38 +0300 Dmitry Bondar <[email protected]> wrote:
Hello, on our board we have one LED with 2 gpio connected to it:
- when gpio0 is on and gpio1 on - LED is orange.
- when gpio0 is on and gpio1 off - LED is green.
- when gpio0 is off and gpio1 on - LED is red.
- when gpio0 is off and gpio1 off - LED is off.
We want use led_trigger (nand-disk) on this LED.
Below patch which we use for get one LED on 2 gpios. Can be this in mainline, or may be exist other - better way?
It sounds like what you have is two independent GPIO controlled LEDs:
one green and the other red (even if they are part of the same IC). Given the current infrastructure, I have modeled such cases as two separate LEDs in the devicetree, named <device>:green:<function> and <device>:red:<function>. Userspace is then responsible for controlling them appropriately to get the desired color.
Unless I'm mistaken, in your case (nand-disk) there are blinking combinations you wouldn't be able to achieve this way, but there are a number you can do:
- off/green: green:nand-disk red:off
- off/red: green:off red:nand-disk
- off/orange: green:nand-disk red:nand-disk
- green/orange: green:on red:nand-disk
- red/orange: green:nand-disk red:on
The other cases (e.g. green/red) would need an inverted nand-disk trigger (on while inactive, off while active).

Quoted 3 lines

I'm hoping that if the RGB LED framework comes to fruition, that there will be some way to combine arbitrary single-color LED devices into a logical RGB LED.

It turns out that rgb-pattern trigger, we were discussing some time ago, would be useful also for LEDs of arbitrary colors. It should be given more generic name then, e.g. three-led-composite or so. The "color" sysfs attribute exposed by the trigger could be replaced with "subled_id", that would accept values 0, 1 or 2.

Brightness of such a compound LED could be set with:

led_trigger_3led_event(sturct led_trigger *trig,
enum led_brightness led1,
enum led_brightness led2,
enum led_brightness led3)

Maybe we should think about making this scalable using C ellipsis feature:

led_trigger_3led_event(sturct led_trigger *trig,
enum led_brightness led1,
...)

Signature · 2 lines

Best regards,
Jacek Anaszewski

Pavel Machek

2016-04-29 12:58 UTC #5 lore raw

Hi!

Quoted 17 lines

Quoted 3 lines
I'm hoping that if the RGB LED framework comes to fruition, that there will be some way to combine arbitrary single-color LED devices into a logical RGB LED.
It turns out that rgb-pattern trigger, we were discussing some time ago, would be useful also for LEDs of arbitrary colors. It should be given more generic name then, e.g. three-led-composite or so. The "color" sysfs attribute exposed by the trigger could be replaced with "subled_id", that would accept values 0, 1 or 2.
Brightness of such a compound LED could be set with:
led_trigger_3led_event(sturct led_trigger *trig,
enum led_brightness led1,
enum led_brightness led2,
enum led_brightness led3)

Quoted 6 lines

Maybe we should think about making this scalable using C ellipsis feature:
led_trigger_3led_event(sturct led_trigger *trig,
enum led_brightness led1,
...)

You don't need (and should not need) elipsis.

led_trigger_many_leds_event(sturct led_trigger *trig,
int num_leds,
enum led_brightness *brightness)

...should be fine.
Pavel

Signature · 2 lines

(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Jacek Anaszewski

2016-04-29 13:07 UTC #6 lore raw

Hi Pavel,

Quoted 26 lines · Pavel Machek

Hi!
Quoted 17 lines
Quoted 3 lines
I'm hoping that if the RGB LED framework comes to fruition, that there will be some way to combine arbitrary single-color LED devices into a logical RGB LED.
It turns out that rgb-pattern trigger, we were discussing some time ago, would be useful also for LEDs of arbitrary colors. It should be given more generic name then, e.g. three-led-composite or so. The "color" sysfs attribute exposed by the trigger could be replaced with "subled_id", that would accept values 0, 1 or 2.
Brightness of such a compound LED could be set with:
led_trigger_3led_event(sturct led_trigger *trig,
enum led_brightness led1,
enum led_brightness led2,
enum led_brightness led3)
Quoted 6 lines
Maybe we should think about making this scalable using C ellipsis feature:
led_trigger_3led_event(sturct led_trigger *trig,
enum led_brightness led1,
...)

Quoted 5 lines

You don't need (and should not need) elipsis.
led_trigger_many_leds_event(sturct led_trigger *trig,
int num_leds,
enum led_brightness *brightness)

Right, this is more straightforward approach.

Signature · 2 lines

Best regards,
Jacek Anaszewski