Add a simple uclass for LEDs, so that these can be controlled by the device tree and activated when needed. LEDs are referred to by their label.
This implementation requires a driver for each type of LED (e.g GPIO, I2C).
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v3: None Changes in v2: None
doc/device-tree-bindings/leds/common.txt | 23 ++++++++++++++ drivers/Kconfig | 2 ++ drivers/Makefile | 1 + drivers/led/Kconfig | 17 +++++++++++ drivers/led/Makefile | 8 +++++ drivers/led/led-uclass.c | 48 ++++++++++++++++++++++++++++++ include/dm/uclass-id.h | 1 + include/led.h | 51 ++++++++++++++++++++++++++++++++ scripts/Makefile.spl | 1 + 9 files changed, 152 insertions(+) create mode 100644 doc/device-tree-bindings/leds/common.txt create mode 100644 drivers/led/Kconfig create mode 100644 drivers/led/Makefile create mode 100644 drivers/led/led-uclass.c create mode 100644 include/led.h
diff --git a/doc/device-tree-bindings/leds/common.txt b/doc/device-tree-bindings/leds/common.txt new file mode 100644 index 0000000..2d88816 --- /dev/null +++ b/doc/device-tree-bindings/leds/common.txt @@ -0,0 +1,23 @@ +Common leds properties. + +Optional properties for child nodes: +- label : The label for this LED. If omitted, the label is + taken from the node name (excluding the unit address). + +- linux,default-trigger : This parameter, if present, is a + string defining the trigger assigned to the LED. Current triggers are: + "backlight" - LED will act as a back-light, controlled by the framebuffer + system + "default-on" - LED will turn on (but for leds-gpio see "default-state" + property in Documentation/devicetree/bindings/gpio/led.txt) + "heartbeat" - LED "double" flashes at a load average based rate + "ide-disk" - LED indicates disk activity + "timer" - LED flashes at a fixed, configurable rate + +Examples: + +system-status { + label = "Status"; + linux,default-trigger = "heartbeat"; + ... +}; diff --git a/drivers/Kconfig b/drivers/Kconfig index 1f40887..ee942e2 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -20,6 +20,8 @@ source "drivers/net/Kconfig"
source "drivers/input/Kconfig"
+source "drivers/led/Kconfig" + source "drivers/serial/Kconfig"
source "drivers/tpm/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 405b64b..c090aba 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_CPU) += cpu/ obj-y += crypto/ obj-$(CONFIG_FPGA) += fpga/ obj-y += hwmon/ +obj-$(CONFIG_LED) += led/ obj-y += misc/ obj-y += pcmcia/ obj-y += dfu/ diff --git a/drivers/led/Kconfig b/drivers/led/Kconfig new file mode 100644 index 0000000..e4d9a84 --- /dev/null +++ b/drivers/led/Kconfig @@ -0,0 +1,17 @@ +config LED + bool "Enable LED support" + depends on DM + help + Many boards have LEDs which can be used to signal status or alerts. + U-Boot provides a uclass API to implement this feature. LED drivers + can provide access to board-specific LEDs. Use of the device tree + for configuration is encouraged. + +config SPL_LED_SUPPORT + bool "Enable LED support in SPL" + depends on LED + help + The LED subsystem adds a small amount of overhead to the image. + If this is acceptable and you have a need to use LEDs in SPL, + enable this option. You will need to enable device tree in SPL + for this to work. diff --git a/drivers/led/Makefile b/drivers/led/Makefile new file mode 100644 index 0000000..b39b205 --- /dev/null +++ b/drivers/led/Makefile @@ -0,0 +1,8 @@ +# +# Copyright (c) 2015 Google, Inc +# Written by Simon Glass sjg@chromium.org +# +# SPDX-License-Identifier: GPL-2.0+ +# + +obj-$(CONFIG_LED) += led-uclass.o diff --git a/drivers/led/led-uclass.c b/drivers/led/led-uclass.c new file mode 100644 index 0000000..a80ae93 --- /dev/null +++ b/drivers/led/led-uclass.c @@ -0,0 +1,48 @@ +/* + * Copyright (c) 2015 Google, Inc + * Written by Simon Glass sjg@chromium.org + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <dm.h> +#include <errno.h> +#include <led.h> +#include <dm/root.h> +#include <dm/uclass-internal.h> + +int led_get_by_label(const char *label, struct udevice **devp) +{ + struct udevice *dev; + struct uclass *uc; + int ret; + + ret = uclass_get(UCLASS_LED, &uc); + if (ret) + return ret; + uclass_foreach_dev(dev, uc) { + struct led_uclass_plat *uc_plat = dev_get_uclass_platdata(dev); + + if (!strcmp(label, uc_plat->label)) + return uclass_get_device_tail(dev, 0, devp); + } + + return -ENOENT; +} + +int led_set_on(struct udevice *dev, int on) +{ + struct led_ops *ops = led_get_ops(dev); + + if (!ops->set_on) + return -ENOSYS; + + return ops->set_on(dev, on); +} + +UCLASS_DRIVER(led) = { + .id = UCLASS_LED, + .name = "led", + .per_device_platdata_auto_alloc_size = sizeof(struct led_uclass_plat), +}; diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index 24baa5c..a961648 100644 --- a/include/dm/uclass-id.h +++ b/include/dm/uclass-id.h @@ -33,6 +33,7 @@ enum uclass_id { UCLASS_I2C, /* I2C bus */ UCLASS_I2C_EEPROM, /* I2C EEPROM device */ UCLASS_I2C_GENERIC, /* Generic I2C device */ + UCLASS_LED, /* Light-emitting diode (LED) */ UCLASS_LPC, /* x86 'low pin count' interface */ UCLASS_MASS_STORAGE, /* Mass storage device */ UCLASS_MOD_EXP, /* RSA Mod Exp device */ diff --git a/include/led.h b/include/led.h new file mode 100644 index 0000000..8925d75 --- /dev/null +++ b/include/led.h @@ -0,0 +1,51 @@ +/* + * Copyright (c) 2015 Google, Inc + * Written by Simon Glass sjg@chromium.org + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef __LED_H +#define __LED_H + +/** + * struct led_uclass_plat - Platform data the uclass stores about each device + * + * @label: LED label + */ +struct led_uclass_plat { + const char *label; +}; + +struct led_ops { + /** + * set_on() - set the state of an LED + * + * @dev: LED device to change + * @on: 1 to turn the LED on, 0 to turn it off + * @return 0 if OK, -ve on error + */ + int (*set_on)(struct udevice *dev, int on); +}; + +#define led_get_ops(dev) ((struct led_ops *)(dev)->driver->ops) + +/** + * led_get_by_label() - Find an LED device by label + * + * @label: LED label to look up + * @devp: Returns the associated device, if found + * @return 0 if found, -ve on error + */ +int led_get_by_label(const char *label, struct udevice **devp); + +/** + * led_set_on() - set the state of an LED + * + * @dev: LED device to change + * @on: 1 to turn the LED on, 0 to turn it off + * @return 0 if OK, -ve on error + */ +int led_set_on(struct udevice *dev, int on); + +#endif diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl index bcc7ca2..6b32618 100644 --- a/scripts/Makefile.spl +++ b/scripts/Makefile.spl @@ -64,6 +64,7 @@ libs-$(CONFIG_SPL_SERIAL_SUPPORT) += drivers/serial/ libs-$(CONFIG_SPL_SPI_FLASH_SUPPORT) += drivers/mtd/spi/ libs-$(CONFIG_SPL_SPI_SUPPORT) += drivers/spi/ libs-y += fs/ +libs-$(CONFIG_SPL_LED_SUPPORT) += drivers/led/ libs-$(CONFIG_SPL_LIBGENERIC_SUPPORT) += lib/ libs-$(CONFIG_SPL_POWER_SUPPORT) += drivers/power/ drivers/power/pmic/ libs-$(CONFIG_SPL_MTD_SUPPORT) += drivers/mtd/