From: Michael Polyntsov michael.polyntsov@iopsys.eu
If hardware (or driver) doesn't support leds blinking, it's now possible to use software implementation of blinking instead. This relies on cyclic functions.
v2 changes: * Drop sw_blink_state structure, move its necessary fields to led_uc_plat structure. * Add cyclic_info pointer to led_uc_plat structure. This simplify code a lot. * Remove cyclic function search logic. Not needed anymore. * Fix blinking period. It was twice large. * Other cleanups.
v3 changes: * Adapt code to recent cyclic function changes * Move software blinking functions to separate file * Other small changes
Signed-off-by: Michael Polyntsov michael.polyntsov@iopsys.eu Signed-off-by: Mikhail Kshevetskiy mikhail.kshevetskiy@iopsys.eu --- drivers/led/Kconfig | 14 +++++ drivers/led/Makefile | 1 + drivers/led/led-uclass.c | 16 +++++- drivers/led/led_sw_blink.c | 106 +++++++++++++++++++++++++++++++++++++ include/led.h | 17 ++++++ 5 files changed, 152 insertions(+), 2 deletions(-) create mode 100644 drivers/led/led_sw_blink.c
diff --git a/drivers/led/Kconfig b/drivers/led/Kconfig index 9837960198d..dc9d4c8a757 100644 --- a/drivers/led/Kconfig +++ b/drivers/led/Kconfig @@ -73,6 +73,20 @@ config LED_BLINK This option enables support for this which adds slightly to the code size.
+config LED_SW_BLINK + bool "Support software LED blinking" + depends on LED_BLINK + select CYCLIC + help + Turns on led blinking implemented in the software, useful when + the hardware doesn't support led blinking. Half of the period + led will be ON and the rest time it will be OFF. Standard + led commands can be used to configure blinking. Does nothing + if driver supports blinking. + WARNING: Blinking may be inaccurate during execution of time + consuming commands (ex. flash reading). Also it completely + stops during OS booting. + config SPL_LED bool "Enable LED support in SPL" depends on SPL_DM diff --git a/drivers/led/Makefile b/drivers/led/Makefile index 2bcb8589087..e27aa488482 100644 --- a/drivers/led/Makefile +++ b/drivers/led/Makefile @@ -4,6 +4,7 @@ # Written by Simon Glass sjg@chromium.org
obj-y += led-uclass.o +obj-$(CONFIG_LED_SW_BLINK) += led_sw_blink.o obj-$(CONFIG_LED_BCM6328) += led_bcm6328.o obj-$(CONFIG_LED_BCM6358) += led_bcm6358.o obj-$(CONFIG_LED_BCM6753) += led_bcm6753.o diff --git a/drivers/led/led-uclass.c b/drivers/led/led-uclass.c index f37bf6a1550..37dc99cecdc 100644 --- a/drivers/led/led-uclass.c +++ b/drivers/led/led-uclass.c @@ -58,6 +58,10 @@ int led_set_state(struct udevice *dev, enum led_state_t state) if (!ops->set_state) return -ENOSYS;
+ if (IS_ENABLED(CONFIG_LED_SW_BLINK) && + led_sw_on_state_change(dev, state)) + return 0; + return ops->set_state(dev, state); }
@@ -68,6 +72,10 @@ enum led_state_t led_get_state(struct udevice *dev) if (!ops->get_state) return -ENOSYS;
+ if (IS_ENABLED(CONFIG_LED_SW_BLINK) && + led_sw_is_blinking(dev)) + return LEDST_BLINK; + return ops->get_state(dev); }
@@ -76,8 +84,12 @@ int led_set_period(struct udevice *dev, int period_ms) { struct led_ops *ops = led_get_ops(dev);
- if (!ops->set_period) - return -ENOSYS; + if (!ops->set_period) { + if (IS_ENABLED(CONFIG_LED_SW_BLINK)) + return led_sw_set_period(dev, period_ms); + else + return -ENOSYS; + }
return ops->set_period(dev, period_ms); } diff --git a/drivers/led/led_sw_blink.c b/drivers/led/led_sw_blink.c new file mode 100644 index 00000000000..ab56111a60b --- /dev/null +++ b/drivers/led/led_sw_blink.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Software blinking helpers + * Copyright (C) 2024 IOPSYS Software Solutions AB + * Author: Mikhail Kshevetskiy mikhail.kshevetskiy@iopsys.eu + */ + +#include <dm.h> +#include <led.h> +#include <time.h> +#include <stdlib.h> + +static void led_sw_blink(struct cyclic_info *c) +{ + struct led_uc_plat *uc_plat; + struct udevice *dev; + struct led_ops *ops; + + uc_plat = container_of(c, struct led_uc_plat, cyclic); + dev = uc_plat->dev; + ops = led_get_ops(dev); + + switch (uc_plat->sw_blink_state) { + case LED_SW_BLINK_ST_OFF: + uc_plat->sw_blink_state = LED_SW_BLINK_ST_ON; + ops->set_state(dev, LEDST_ON); + break; + case LED_SW_BLINK_ST_ON: + uc_plat->sw_blink_state = LED_SW_BLINK_ST_OFF; + ops->set_state(dev, LEDST_OFF); + break; + case LED_SW_BLINK_ST_NOT_READY: + /* + * led_set_period has been called, but + * led_set_state(LDST_BLINK) has not yet, + * so doing nothing + */ + break; + default: + break; + } +} + +int led_sw_set_period(struct udevice *dev, int period_ms) +{ + struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev); + struct cyclic_info *cyclic = &uc_plat->cyclic; + struct led_ops *ops = led_get_ops(dev); + int half_period_us; + char *name; + int len; + + half_period_us = period_ms * 1000 / 2; + + name = (char *)cyclic->name; + if (name == NULL) { + len = snprintf(NULL, 0, "led_sw_blink_%s", uc_plat->label); + if (len <= 0) + return -ENOMEM; + + name = malloc(len + 1); + if (!name) + return -ENOMEM; + + snprintf(name, len + 1, "led_sw_blink_%s", uc_plat->label); + } + + if (uc_plat->sw_blink_state == LED_SW_BLINK_ST_DISABLED) { + uc_plat->dev = dev; + cyclic_register(cyclic, led_sw_blink, half_period_us, name); + } else { + cyclic->delay_us = half_period_us; + cyclic->start_time_us = timer_get_us(); + } + + uc_plat->sw_blink_state = LED_SW_BLINK_ST_NOT_READY; + ops->set_state(dev, LEDST_OFF); + + return 0; +} + +bool led_sw_is_blinking(struct udevice *dev) +{ + struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev); + + return (uc_plat->sw_blink_state > LED_SW_BLINK_ST_NOT_READY); +} + +bool led_sw_on_state_change(struct udevice *dev, enum led_state_t state) +{ + struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev); + + if (uc_plat->sw_blink_state != LED_SW_BLINK_ST_DISABLED) { + if (state == LEDST_BLINK) { + /* start blinking on next led_sw_blink() call */ + uc_plat->sw_blink_state = LED_SW_BLINK_ST_OFF; + return true; + } + + /* stop blinking */ + cyclic_unregister(&uc_plat->cyclic); + uc_plat->sw_blink_state = LED_SW_BLINK_ST_DISABLED; + } + + return false; +} diff --git a/include/led.h b/include/led.h index a6353166289..26955269d3e 100644 --- a/include/led.h +++ b/include/led.h @@ -20,6 +20,13 @@ enum led_state_t { LEDST_COUNT, };
+enum led_sw_blink_state_t { + LED_SW_BLINK_ST_DISABLED, + LED_SW_BLINK_ST_NOT_READY, + LED_SW_BLINK_ST_OFF, + LED_SW_BLINK_ST_ON, +}; + /** * struct led_uc_plat - Platform data the uclass stores about each device * @@ -29,6 +36,11 @@ enum led_state_t { struct led_uc_plat { const char *label; enum led_state_t default_state; +#ifdef CONFIG_LED_SW_BLINK + struct udevice *dev; + struct cyclic_info cyclic; + enum led_sw_blink_state_t sw_blink_state; +#endif };
/** @@ -118,4 +130,9 @@ int led_set_period(struct udevice *dev, int period_ms); */ int led_bind_generic(struct udevice *parent, const char *driver_name);
+/* Internal functions for software blinking. Do not use them in your code */ +int led_sw_set_period(struct udevice *dev, int period_ms); +bool led_sw_is_blinking(struct udevice *dev); +bool led_sw_on_state_change(struct udevice *dev, enum led_state_t state); + #endif