[1/2,v6] dt-bindings: leds: Add DT binding for Richtek RT8515
Commit Message
Add a YAML devicetree binding for the Richtek RT8515
dual channel flash/torch LED driver.
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Cc: newbytee@protonmail.com
Cc: Stephan Gerhold <stephan@gerhold.net>
Cc: phone-devel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v5->v6:
- Use the suffix -ohms for the resistor values as this gets
recognized by default by dtschema and is nominal.
ChangeLog v4->v5:
- Fix the RFS/RTS resistors to reference the u32 schema.
- Fix resisitor speling error.
ChangeLog v3->v4:
- Add DT attributes for the RFS and RTS resistors, so that
the hardware-defined maximum current can be determined.
- Add torch-max-microamp to the common bindings so we can
set an attribute for the max microamp in torch mode.
- Add flash-max-microamp and torch-max-microamp as optional
to the LED node.
- Slot in some elabortative descriptions of the new
properties and describe what the hardware is doing.
- Cc phone-devel@vger.kernel.org
ChangeLog v2->v3:
- Add Sakari to CC
- Resend
ChangeLog v1->v2:
- Explicitly inherit function, color and flash-max-timeout-us
from common.yaml
- Add "led" node as required.
---
.../devicetree/bindings/leds/common.yaml | 6 +
.../bindings/leds/richtek,rt8515.yaml | 109 ++++++++++++++++++
2 files changed, 115 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/richtek,rt8515.yaml
Comments
Hi Linus,
On Mon, Nov 23, 2020 at 10:44:38PM +0100, Linus Walleij wrote:
> diff --git a/Documentation/devicetree/bindings/leds/common.yaml b/Documentation/devicetree/bindings/leds/common.yaml
> index f1211e7045f1..92fa90b4a671 100644
> --- a/Documentation/devicetree/bindings/leds/common.yaml
> +++ b/Documentation/devicetree/bindings/leds/common.yaml
> @@ -151,6 +151,12 @@ properties:
> Maximum flash LED supply current in microamperes. Required for flash LED
> nodes with configurable current.
>
> + torch-max-microamp:
> + description:
> + Maximum flash LED supply current in microamperes, when the flash LED is
> + used as a torch (flashlight). This is usually lower than the flash mode
> + maximum current, if the LED supports torch mode.
Thanks for the update.
One more thing. The other flash LED DT bindings are using led-max-microamp
for the torch mode --- for it's what the non-flash LEDs do.
Could you use the same here?
With that, for the set:
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
On Tue, Nov 24, 2020 at 12:45:43AM +0200, Sakari Ailus wrote:
> Hi Linus,
>
> On Mon, Nov 23, 2020 at 10:44:38PM +0100, Linus Walleij wrote:
> > diff --git a/Documentation/devicetree/bindings/leds/common.yaml b/Documentation/devicetree/bindings/leds/common.yaml
> > index f1211e7045f1..92fa90b4a671 100644
> > --- a/Documentation/devicetree/bindings/leds/common.yaml
> > +++ b/Documentation/devicetree/bindings/leds/common.yaml
> > @@ -151,6 +151,12 @@ properties:
> > Maximum flash LED supply current in microamperes. Required for flash LED
> > nodes with configurable current.
> >
> > + torch-max-microamp:
> > + description:
> > + Maximum flash LED supply current in microamperes, when the flash LED is
> > + used as a torch (flashlight). This is usually lower than the flash mode
> > + maximum current, if the LED supports torch mode.
>
> Thanks for the update.
>
> One more thing. The other flash LED DT bindings are using led-max-microamp
> for the torch mode --- for it's what the non-flash LEDs do.
>
> Could you use the same here?
Good point. Seems like it as led-max-microamp should be the max steady
state current whereas flash-max-microamp is the max for a limited time.
Rob
@@ -151,6 +151,12 @@ properties:
Maximum flash LED supply current in microamperes. Required for flash LED
nodes with configurable current.
+ torch-max-microamp:
+ description:
+ Maximum flash LED supply current in microamperes, when the flash LED is
+ used as a torch (flashlight). This is usually lower than the flash mode
+ maximum current, if the LED supports torch mode.
+
flash-max-timeout-us:
description:
Maximum timeout in microseconds after which the flash LED is turned off.
new file mode 100644
@@ -0,0 +1,109 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/richtek,rt8515.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Richtek RT8515 1.5A dual channel LED driver
+
+maintainers:
+ - Linus Walleij <linus.walleij@linaro.org>
+
+description: |
+ The Richtek RT8515 is a dual channel (two mode) LED driver that
+ supports driving a white LED in flash or torch mode. The maximum
+ current for each mode is defined in hardware using two resistors
+ RFS and RTS.
+
+properties:
+ compatible:
+ const: richtek,rt8515
+
+ enf-gpios:
+ maxItems: 1
+ description: A connection to the 'ENF' (enable flash) pin.
+
+ ent-gpios:
+ maxItems: 1
+ description: A connection to the 'ENT' (enable torch) pin.
+
+ richtek,rfs-ohms:
+ minimum: 7680
+ maximum: 367000
+ description: The resistance value of the RFS resistor. This
+ resistors limits the maximum flash current. This must be set
+ for the property flash-max-microamp to work, the RFS resistor
+ defines the range of the dimmer setting (brightness) of the
+ flash LED.
+
+ richtek,rts-ohms:
+ minimum: 7680
+ maximum: 367000
+ description: The resistance value of the RTS resistor. This
+ resistors limits the maximum torch current. This must be set
+ for the property torch-max-microamp to work, the RTS resistor
+ defines the range of the dimmer setting (brightness) of the
+ torch LED.
+
+ led:
+ type: object
+ $ref: common.yaml#
+ properties:
+ function: true
+ color: true
+ flash-max-timeout-us: true
+
+ flash-max-microamp:
+ maximum: 700000
+ description: The maximum current for flash mode
+ is hardwired to the component using the RFS resistor to
+ ground. The maximum hardware current setting is calculated
+ according to the formula Imax = 5500 / RFS. The lowest
+ allowed resistance value is 7.86 kOhm giving an absolute
+ maximum current of 700mA. By setting this attribute in
+ the device tree, you can further restrict the maximum
+ current below the hardware limit. This requires the RFS
+ to be defined as it defines the maximum range.
+
+ torch-max-microamp:
+ maximum: 700000
+ description: The maximum current for torch mode
+ is hardwired to the component using the RTS resistor to
+ ground. The maximum hardware current setting is calculated
+ according to the formula Imax = 5500 / RTS. The lowest
+ allowed resistance value is 7.86 kOhm giving an absolute
+ maximum current of 700mA. By setting this attribute in
+ the device tree, you can further restrict the maximum
+ current below the hardware limit. This requires the RTS
+ to be defined as it defines the maximum range.
+
+required:
+ - compatible
+ - ent-gpios
+ - enf-gpios
+ - led
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ #include <dt-bindings/leds/common.h>
+
+ led-controller {
+ compatible = "richtek,rt8515";
+ enf-gpios = <&gpio4 12 GPIO_ACTIVE_HIGH>;
+ ent-gpios = <&gpio4 13 GPIO_ACTIVE_HIGH>;
+ richtek,rfs-ohms = <16000>;
+ richtek,rts-ohms = <100000>;
+
+ led {
+ function = LED_FUNCTION_FLASH;
+ color = <LED_COLOR_ID_WHITE>;
+ flash-max-timeout-us = <250000>;
+ flash-max-microamp = <150000>;
+ torch-max-microamp = <25000>;
+ };
+ };
+
+...