2021-03-26 05:35:21

by Hermes Zhang

[permalink] [raw]
Subject: [PATCH v2 0/2] New multiple GPIOs LED driver

From: Hermes Zhang <[email protected]>

changes v2:
- use max_brightness(=2^gpio number) instead of LED_FULL
- alloc priv at once
- move driver code to new simple folder
- update commit message for dt-binding commit
- move dt-binding commit before driver code

Hermes Zhang (2):
dt-binding: leds: Document leds-multi-gpio bindings
leds: leds-multi-gpio: Add multiple GPIOs LED driver

.../bindings/leds/leds-multi-gpio.yaml | 50 ++++++
drivers/leds/Kconfig | 3 +
drivers/leds/Makefile | 3 +
drivers/leds/simple/Kconfig | 23 +++
drivers/leds/simple/Makefile | 3 +
drivers/leds/simple/leds-multi-gpio.c | 144 ++++++++++++++++++
6 files changed, 226 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml
create mode 100644 drivers/leds/simple/Kconfig
create mode 100644 drivers/leds/simple/Makefile
create mode 100644 drivers/leds/simple/leds-multi-gpio.c

--
2.20.1


2021-03-26 05:35:49

by Hermes Zhang

[permalink] [raw]
Subject: [PATCH v2 1/2] dt-binding: leds: Document leds-multi-gpio bindings

From: Hermes Zhang <[email protected]>

This binding represents LED devices which are controller with
multiple GPIO lines in order to achieve more than two brightness
states.

Signed-off-by: Hermes Zhang <[email protected]>
---
.../bindings/leds/leds-multi-gpio.yaml | 50 +++++++++++++++++++
1 file changed, 50 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml

diff --git a/Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml b/Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml
new file mode 100644
index 000000000000..1549f21e8d6e
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/leds-multi-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Multiple GPIOs LED driver
+
+maintainers:
+ - Hermes Zhang <[email protected]>
+
+description:
+ This will support some LED made of multiple GPIOs and the brightness of the
+ LED could map to different states of the GPIOs.
+
+properties:
+ compatible:
+ const: multi-gpio-led
+
+ led-gpios:
+ description: Array of one or more GPIOs pins used to control the LED.
+ minItems: 1
+ maxItems: 8 # Should be enough
+
+ led-states:
+ description: |
+ The array list the supported states here which will map to brightness
+ from 0 to maximum. Each item in the array will present all the GPIOs
+ value by bit.
+ $ref: /schemas/types.yaml#/definitions/uint8-array
+ minItems: 1
+ maxItems: 256 # Should be enough
+
+required:
+ - compatible
+ - led-gpios
+ - led-states
+
+additionalProperties: false
+
+examples:
+ - |
+ gpios-led {
+ compatible = "multi-gpio-led";
+
+ led-gpios = <&gpio0 23 0x1>,
+ <&gpio0 24 0x1>;
+ led-states = /bits/ 8 <0x00 0x01 0x02 0x03>;
+ };
+...
--
2.20.1

2021-03-26 05:37:32

by Hermes Zhang

[permalink] [raw]
Subject: [PATCH v2 2/2] leds: leds-multi-gpio: Add multiple GPIOs LED driver

From: Hermes Zhang <[email protected]>

Introduce a new multiple GPIOs LED driver. This LED will made of
multiple GPIOs (up to 8) and will map different brightness to different
GPIOs states which defined in dts file.

Signed-off-by: Hermes Zhang <[email protected]>
---
drivers/leds/Kconfig | 3 +
drivers/leds/Makefile | 3 +
drivers/leds/simple/Kconfig | 23 ++++
drivers/leds/simple/Makefile | 3 +
drivers/leds/simple/leds-multi-gpio.c | 144 ++++++++++++++++++++++++++
5 files changed, 176 insertions(+)
create mode 100644 drivers/leds/simple/Kconfig
create mode 100644 drivers/leds/simple/Makefile
create mode 100644 drivers/leds/simple/leds-multi-gpio.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index b6742b4231bf..f95217b2fcf1 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -937,4 +937,7 @@ source "drivers/leds/trigger/Kconfig"
comment "LED Blink"
source "drivers/leds/blink/Kconfig"

+comment "LED Simple"
+source "drivers/leds/simple/Kconfig"
+
endif # NEW_LEDS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index 2a698df9da57..26917d93fa03 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -111,3 +111,6 @@ obj-$(CONFIG_LEDS_TRIGGERS) += trigger/

# LED Blink
obj-$(CONFIG_LEDS_BLINK) += blink/
+
+# LED Blink
+obj-$(CONFIG_LEDS_SIMPLE) += simple/
diff --git a/drivers/leds/simple/Kconfig b/drivers/leds/simple/Kconfig
new file mode 100644
index 000000000000..7aef82701f86
--- /dev/null
+++ b/drivers/leds/simple/Kconfig
@@ -0,0 +1,23 @@
+menuconfig LEDS_SIMPLE
+ bool "Simple LED support"
+ depends on LEDS_CLASS
+ help
+ This option enables simple leds support for the leds class.
+ If unsure, say Y.
+
+if LEDS_SIMPLE
+
+config LEDS_MULTI_GPIO
+ tristate "LED Support for multiple GPIOs LED"
+ depends on LEDS_CLASS
+ depends on GPIOLIB
+ depends on OF
+ help
+ This option enables support for a multiple GPIOs LED. Such LED is made
+ of multiple GPIOs and could change the brightness by setting different
+ states of the GPIOs.
+
+ To compile this driver as a module, choose M here: the
+ module will be called leds-multi-gpio.
+
+endif # LEDS_SIMPLE
diff --git a/drivers/leds/simple/Makefile b/drivers/leds/simple/Makefile
new file mode 100644
index 000000000000..2ba655fdc175
--- /dev/null
+++ b/drivers/leds/simple/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_LEDS_MULTI_GPIO) += leds-multi-gpio.o
diff --git a/drivers/leds/simple/leds-multi-gpio.c b/drivers/leds/simple/leds-multi-gpio.c
new file mode 100644
index 000000000000..14fdaa5a2aac
--- /dev/null
+++ b/drivers/leds/simple/leds-multi-gpio.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Axis Communications AB
+ */
+
+#include <linux/leds.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+
+#define MAX_GPIO_NUM 8
+
+struct multi_gpio_led_priv {
+ struct led_classdev cdev;
+
+ struct gpio_descs *gpios;
+
+ u16 nr_states;
+
+ u8 states[0];
+};
+
+
+static void multi_gpio_led_set(struct led_classdev *led_cdev,
+ enum led_brightness value)
+{
+ struct multi_gpio_led_priv *priv;
+ int idx;
+
+ DECLARE_BITMAP(values, MAX_GPIO_NUM);
+
+ priv = container_of(led_cdev, struct multi_gpio_led_priv, cdev);
+
+ idx = value > led_cdev->max_brightness ? led_cdev->max_brightness : value;
+
+ values[0] = priv->states[idx];
+
+ gpiod_set_array_value(priv->gpios->ndescs, priv->gpios->desc,
+ priv->gpios->info, values);
+}
+
+static int multi_gpio_led_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+ struct multi_gpio_led_priv *priv = NULL;
+ int ret;
+ const char *state = NULL;
+ struct led_init_data init_data = {};
+ struct gpio_descs *gpios;
+ u16 nr_states;
+
+ gpios = devm_gpiod_get_array(dev, "led", GPIOD_OUT_LOW);
+ if (IS_ERR(gpios))
+ return PTR_ERR(gpios);
+
+ if (gpios->ndescs >= MAX_GPIO_NUM) {
+ dev_err(dev, "Too many GPIOs\n");
+ return -EINVAL;
+ }
+
+ ret = of_property_count_u8_elems(node, "led-states");
+ if (ret < 0)
+ return ret;
+
+ if (ret != 1 << gpios->ndescs) {
+ dev_err(dev, "led-states number should equal to 2^led-gpios\n");
+ return -EINVAL;
+ }
+
+ nr_states = ret;
+
+ priv = devm_kzalloc(dev, sizeof(struct multi_gpio_led_priv)
+ + sizeof(u8) * nr_states , GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ ret = of_property_read_u8_array(node, "led-states", priv->states, nr_states);
+ if (ret)
+ return ret;
+
+ priv->gpios = gpios;
+ priv->nr_states = nr_states;
+
+ priv->cdev.max_brightness = nr_states;
+ priv->cdev.default_trigger = of_get_property(node, "linux,default-trigger", NULL);
+ priv->cdev.brightness_set = multi_gpio_led_set;
+
+ init_data.fwnode = of_fwnode_handle(node);
+
+ ret = devm_led_classdev_register_ext(dev, &priv->cdev, &init_data);
+ if (ret < 0)
+ return ret;
+
+ of_property_read_string(node, "default-state", &state);
+ if (!strcmp(state, "on"))
+ multi_gpio_led_set(&priv->cdev, priv->cdev.max_brightness);
+ else
+ multi_gpio_led_set(&priv->cdev, 0);
+
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+}
+
+static void multi_gpio_led_shutdown(struct platform_device *pdev)
+{
+ struct multi_gpio_led_priv *priv = platform_get_drvdata(pdev);
+
+ multi_gpio_led_set(&priv->cdev, 0);
+}
+
+static int multi_gpio_led_remove(struct platform_device *pdev)
+{
+ multi_gpio_led_shutdown(pdev);
+
+ return 0;
+}
+
+static const struct of_device_id of_multi_gpio_led_match[] = {
+ { .compatible = "multi-gpio-led", },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, of_multi_gpio_led_match);
+
+static struct platform_driver multi_gpio_led_driver = {
+ .probe = multi_gpio_led_probe,
+ .remove = multi_gpio_led_remove,
+ .shutdown = multi_gpio_led_shutdown,
+ .driver = {
+ .name = "multi-gpio-led",
+ .of_match_table = of_multi_gpio_led_match,
+ },
+};
+
+module_platform_driver(multi_gpio_led_driver);
+
+MODULE_AUTHOR("Hermes Zhang <[email protected]>");
+MODULE_DESCRIPTION("Multiple GPIOs LED driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:leds-multi-gpio");
--
2.20.1

2021-03-26 05:59:59

by Alexander Dahl

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] leds: leds-multi-gpio: Add multiple GPIOs LED driver

Hello Hermes,

great to see your improved series. See below for my remarks.

On Fri, Mar 26, 2021 at 01:28:01PM +0800, Hermes Zhang wrote:
> From: Hermes Zhang <[email protected]>
>
> Introduce a new multiple GPIOs LED driver. This LED will made of
> multiple GPIOs (up to 8) and will map different brightness to different
> GPIOs states which defined in dts file.
>
> Signed-off-by: Hermes Zhang <[email protected]>
> ---
> drivers/leds/Kconfig | 3 +
> drivers/leds/Makefile | 3 +
> drivers/leds/simple/Kconfig | 23 ++++
> drivers/leds/simple/Makefile | 3 +
> drivers/leds/simple/leds-multi-gpio.c | 144 ++++++++++++++++++++++++++
> 5 files changed, 176 insertions(+)
> create mode 100644 drivers/leds/simple/Kconfig
> create mode 100644 drivers/leds/simple/Makefile
> create mode 100644 drivers/leds/simple/leds-multi-gpio.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index b6742b4231bf..f95217b2fcf1 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -937,4 +937,7 @@ source "drivers/leds/trigger/Kconfig"
> comment "LED Blink"
> source "drivers/leds/blink/Kconfig"
>
> +comment "LED Simple"
> +source "drivers/leds/simple/Kconfig"
> +
> endif # NEW_LEDS
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index 2a698df9da57..26917d93fa03 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -111,3 +111,6 @@ obj-$(CONFIG_LEDS_TRIGGERS) += trigger/
>
> # LED Blink
> obj-$(CONFIG_LEDS_BLINK) += blink/
> +
> +# LED Blink
> +obj-$(CONFIG_LEDS_SIMPLE) += simple/

That comment should read "LED Simple", right?

> diff --git a/drivers/leds/simple/Kconfig b/drivers/leds/simple/Kconfig
> new file mode 100644
> index 000000000000..7aef82701f86
> --- /dev/null
> +++ b/drivers/leds/simple/Kconfig
> @@ -0,0 +1,23 @@
> +menuconfig LEDS_SIMPLE
> + bool "Simple LED support"
> + depends on LEDS_CLASS
> + help
> + This option enables simple leds support for the leds class.
> + If unsure, say Y.
> +
> +if LEDS_SIMPLE
> +
> +config LEDS_MULTI_GPIO
> + tristate "LED Support for multiple GPIOs LED"
> + depends on LEDS_CLASS
> + depends on GPIOLIB
> + depends on OF
> + help
> + This option enables support for a multiple GPIOs LED. Such LED is made
> + of multiple GPIOs and could change the brightness by setting different
> + states of the GPIOs.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called leds-multi-gpio.
> +
> +endif # LEDS_SIMPLE

I'm wondering why this is part of this driver? I suppose there's no
such folder yet, although Pavel suggested. Would it make sense to put
that Kconfig menu entry and folder creation to a separate commit?

> diff --git a/drivers/leds/simple/Makefile b/drivers/leds/simple/Makefile
> new file mode 100644
> index 000000000000..2ba655fdc175
> --- /dev/null
> +++ b/drivers/leds/simple/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +obj-$(CONFIG_LEDS_MULTI_GPIO) += leds-multi-gpio.o
> diff --git a/drivers/leds/simple/leds-multi-gpio.c b/drivers/leds/simple/leds-multi-gpio.c
> new file mode 100644
> index 000000000000..14fdaa5a2aac
> --- /dev/null
> +++ b/drivers/leds/simple/leds-multi-gpio.c
> @@ -0,0 +1,144 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Axis Communications AB
> + */
> +
> +#include <linux/leds.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +
> +
> +#define MAX_GPIO_NUM 8
> +
> +struct multi_gpio_led_priv {
> + struct led_classdev cdev;
> +
> + struct gpio_descs *gpios;
> +
> + u16 nr_states;
> +
> + u8 states[0];
> +};
> +
> +
> +static void multi_gpio_led_set(struct led_classdev *led_cdev,
> + enum led_brightness value)
> +{
> + struct multi_gpio_led_priv *priv;
> + int idx;
> +
> + DECLARE_BITMAP(values, MAX_GPIO_NUM);
> +
> + priv = container_of(led_cdev, struct multi_gpio_led_priv, cdev);
> +
> + idx = value > led_cdev->max_brightness ? led_cdev->max_brightness : value;
> +
> + values[0] = priv->states[idx];
> +
> + gpiod_set_array_value(priv->gpios->ndescs, priv->gpios->desc,
> + priv->gpios->info, values);
> +}
> +
> +static int multi_gpio_led_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *node = dev->of_node;
> + struct multi_gpio_led_priv *priv = NULL;
> + int ret;
> + const char *state = NULL;
> + struct led_init_data init_data = {};
> + struct gpio_descs *gpios;
> + u16 nr_states;
> +
> + gpios = devm_gpiod_get_array(dev, "led", GPIOD_OUT_LOW);
> + if (IS_ERR(gpios))
> + return PTR_ERR(gpios);
> +
> + if (gpios->ndescs >= MAX_GPIO_NUM) {
> + dev_err(dev, "Too many GPIOs\n");
> + return -EINVAL;
> + }
> +
> + ret = of_property_count_u8_elems(node, "led-states");
> + if (ret < 0)
> + return ret;
> +
> + if (ret != 1 << gpios->ndescs) {
> + dev_err(dev, "led-states number should equal to 2^led-gpios\n");
> + return -EINVAL;
> + }
> +
> + nr_states = ret;
> +
> + priv = devm_kzalloc(dev, sizeof(struct multi_gpio_led_priv)
> + + sizeof(u8) * nr_states , GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + ret = of_property_read_u8_array(node, "led-states", priv->states, nr_states);
> + if (ret)
> + return ret;
> +
> + priv->gpios = gpios;
> + priv->nr_states = nr_states;
> +
> + priv->cdev.max_brightness = nr_states;
> + priv->cdev.default_trigger = of_get_property(node, "linux,default-trigger", NULL);
> + priv->cdev.brightness_set = multi_gpio_led_set;
> +
> + init_data.fwnode = of_fwnode_handle(node);
> +
> + ret = devm_led_classdev_register_ext(dev, &priv->cdev, &init_data);
> + if (ret < 0)
> + return ret;
> +
> + of_property_read_string(node, "default-state", &state);
> + if (!strcmp(state, "on"))
> + multi_gpio_led_set(&priv->cdev, priv->cdev.max_brightness);
> + else
> + multi_gpio_led_set(&priv->cdev, 0);
> +
> + platform_set_drvdata(pdev, priv);
> +
> + return 0;
> +}
> +
> +static void multi_gpio_led_shutdown(struct platform_device *pdev)
> +{
> + struct multi_gpio_led_priv *priv = platform_get_drvdata(pdev);
> +
> + multi_gpio_led_set(&priv->cdev, 0);
> +}
> +
> +static int multi_gpio_led_remove(struct platform_device *pdev)
> +{
> + multi_gpio_led_shutdown(pdev);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id of_multi_gpio_led_match[] = {
> + { .compatible = "multi-gpio-led", },
> + {},
> +};
> +
> +MODULE_DEVICE_TABLE(of, of_multi_gpio_led_match);
> +
> +static struct platform_driver multi_gpio_led_driver = {
> + .probe = multi_gpio_led_probe,
> + .remove = multi_gpio_led_remove,
> + .shutdown = multi_gpio_led_shutdown,
> + .driver = {
> + .name = "multi-gpio-led",
> + .of_match_table = of_multi_gpio_led_match,
> + },
> +};
> +
> +module_platform_driver(multi_gpio_led_driver);
> +
> +MODULE_AUTHOR("Hermes Zhang <[email protected]>");
> +MODULE_DESCRIPTION("Multiple GPIOs LED driver");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:leds-multi-gpio");

I did not review thouroughly, but in my mail the indentation looks
wrong. Did checkpatch complain?

Greets
Alex

--
/"\ ASCII RIBBON | ?With the first link, the chain is forged. The first
\ / CAMPAIGN | speech censured, the first thought forbidden, the
X AGAINST | first freedom denied, chains us all irrevocably.?
/ \ HTML MAIL | (Jean-Luc Picard, quoting Judge Aaron Satie)


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2021-03-26 06:11:16

by Hermes Zhang

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] leds: leds-multi-gpio: Add multiple GPIOs LED driver

On 3/26/21 1:56 PM, Alexander Dahl wrote:
>> +
>> +module_platform_driver(multi_gpio_led_driver);
>> +
>> +MODULE_AUTHOR("Hermes Zhang <[email protected]>");
>> +MODULE_DESCRIPTION("Multiple GPIOs LED driver");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_ALIAS("platform:leds-multi-gpio");
> I did not review thouroughly, but in my mail the indentation looks
> wrong. Did checkpatch complain?

Sorry, I forgot to check the style before commit, but seems one problem
about extra space:

$ chkernel
ERROR: space prohibited before that ',' (ctx:WxW)
#164: FILE: drivers/leds/simple/leds-multi-gpio.c:76:
+ + sizeof(u8) * nr_states , GFP_KERNEL);
^

I will fix it in next commit.


Best Regards,

Hermes


2021-03-26 13:53:47

by Pavel Machek

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] leds: leds-multi-gpio: Add multiple GPIOs LED driver

Hi!

> Introduce a new multiple GPIOs LED driver. This LED will made of
> multiple GPIOs (up to 8) and will map different brightness to different
> GPIOs states which defined in dts file.
>
> Signed-off-by: Hermes Zhang <[email protected]>


> index 000000000000..7aef82701f86
> --- /dev/null
> +++ b/drivers/leds/simple/Kconfig
> @@ -0,0 +1,23 @@
> +menuconfig LEDS_SIMPLE
> + bool "Simple LED support"
> + depends on LEDS_CLASS
> + help
> + This option enables simple leds support for the leds class.
> + If unsure, say Y.

No need for new config symbol.

> + if (ret != 1 << gpios->ndescs) {

I'd do (ret != (1 << gpios->ndescs))

> + priv = devm_kzalloc(dev, sizeof(struct multi_gpio_led_priv)
> + + sizeof(u8) * nr_states , GFP_KERNEL);

Sizeof(u8) is always 1, no need for space before , .

> + of_property_read_string(node, "default-state", &state);
> + if (!strcmp(state, "on"))
> + multi_gpio_led_set(&priv->cdev, priv->cdev.max_brightness);
> + else
> + multi_gpio_led_set(&priv->cdev, 0);

No need for default-state handling, unless you are using it.

Best regards,
Pavel

--
http://www.livejournal.com/~pavelmachek


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2021-03-27 18:16:42

by Rob Herring (Arm)

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] dt-binding: leds: Document leds-multi-gpio bindings

On Fri, Mar 26, 2021 at 01:28:00PM +0800, Hermes Zhang wrote:
> From: Hermes Zhang <[email protected]>
>
> This binding represents LED devices which are controller with
> multiple GPIO lines in order to achieve more than two brightness
> states.
>
> Signed-off-by: Hermes Zhang <[email protected]>
> ---
> .../bindings/leds/leds-multi-gpio.yaml | 50 +++++++++++++++++++
> 1 file changed, 50 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml
>
> diff --git a/Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml b/Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml
> new file mode 100644
> index 000000000000..1549f21e8d6e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml
> @@ -0,0 +1,50 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/leds/leds-multi-gpio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Multiple GPIOs LED driver
> +
> +maintainers:
> + - Hermes Zhang <[email protected]>
> +
> +description:
> + This will support some LED made of multiple GPIOs and the brightness of the
> + LED could map to different states of the GPIOs.
> +
> +properties:
> + compatible:
> + const: multi-gpio-led
> +
> + led-gpios:
> + description: Array of one or more GPIOs pins used to control the LED.
> + minItems: 1
> + maxItems: 8 # Should be enough
> +
> + led-states:
> + description: |
> + The array list the supported states here which will map to brightness
> + from 0 to maximum. Each item in the array will present all the GPIOs
> + value by bit.
> + $ref: /schemas/types.yaml#/definitions/uint8-array
> + minItems: 1
> + maxItems: 256 # Should be enough

Isn't this the same as the standard 'brightness-levels' from backlight
binding? The index is the level and the value is the h/w specific
setting.

> +
> +required:
> + - compatible
> + - led-gpios
> + - led-states
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + gpios-led {
> + compatible = "multi-gpio-led";
> +
> + led-gpios = <&gpio0 23 0x1>,
> + <&gpio0 24 0x1>;
> + led-states = /bits/ 8 <0x00 0x01 0x02 0x03>;
> + };
> +...
> --
> 2.20.1
>

2021-03-29 06:02:30

by Hermes Zhang

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] leds: leds-multi-gpio: Add multiple GPIOs LED driver

On 3/26/21 9:49 PM, Pavel Machek wrote:
>> + of_property_read_string(node, "default-state", &state);
>> + if (!strcmp(state, "on"))
>> + multi_gpio_led_set(&priv->cdev, priv->cdev.max_brightness);
>> + else
>> + multi_gpio_led_set(&priv->cdev, 0);
> No need for default-state handling, unless you are using it.
>
We will use it, to make the LED default on or off.


Best Regards,

Hermes

2021-03-29 06:04:56

by Hermes Zhang

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] dt-binding: leds: Document leds-multi-gpio bindings

On 3/28/21 2:12 AM, Rob Herring wrote:
>> +
>> + led-gpios:
>> + description: Array of one or more GPIOs pins used to control the LED.
>> + minItems: 1
>> + maxItems: 8 # Should be enough
>> +
>> + led-states:
>> + description: |
>> + The array list the supported states here which will map to brightness
>> + from 0 to maximum. Each item in the array will present all the GPIOs
>> + value by bit.
>> + $ref: /schemas/types.yaml#/definitions/uint8-array
>> + minItems: 1
>> + maxItems: 256 # Should be enough
> Isn't this the same as the standard 'brightness-levels' from backlight
> binding? The index is the level and the value is the h/w specific
> setting.

Yes, it seems same.


Best Regards,

Hermes