led: Implement software led blinking
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.
Signed-off-by: Michael Polyntsov <michael.polyntsov@iopsys.eu>
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/led/Kconfig b/drivers/led/Kconfig
index 9837960..bee74b2 100644
--- a/drivers/led/Kconfig
+++ b/drivers/led/Kconfig
@@ -65,7 +65,7 @@
Linux compatible ofdata.
config LED_BLINK
- bool "Support LED blinking"
+ bool "Support hardware LED blinking"
depends on LED
help
Some drivers can support automatic blinking of LEDs with a given
@@ -73,6 +73,20 @@
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
+ 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 hardware 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 2bcb858..e27aa48 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 4932b90..e6312d1 100644
--- a/drivers/led/led-uclass.c
+++ b/drivers/led/led-uclass.c
@@ -58,6 +58,10 @@
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 @@
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);
}
@@ -80,6 +88,9 @@
return ops->set_period(dev, period_ms);
#endif
+ if (IS_ENABLED(CONFIG_LED_SW_BLINK))
+ return led_sw_set_period(dev, period_ms);
+
return -ENOSYS;
}
diff --git a/drivers/led/led_sw_blink.c b/drivers/led/led_sw_blink.c
new file mode 100644
index 0000000..9e36edb
--- /dev/null
+++ b/drivers/led/led_sw_blink.c
@@ -0,0 +1,117 @@
+// 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>
+
+#define CYCLIC_NAME_PREFIX "led_sw_blink_"
+
+static void led_sw_blink(struct cyclic_info *c)
+{
+ struct led_sw_blink *sw_blink;
+ struct udevice *dev;
+ struct led_ops *ops;
+
+ sw_blink = container_of(c, struct led_sw_blink, cyclic);
+ dev = sw_blink->dev;
+ ops = led_get_ops(dev);
+
+ switch (sw_blink->state) {
+ case LED_SW_BLINK_ST_OFF:
+ sw_blink->state = LED_SW_BLINK_ST_ON;
+ ops->set_state(dev, LEDST_ON);
+ break;
+ case LED_SW_BLINK_ST_ON:
+ 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 led_sw_blink *sw_blink = uc_plat->sw_blink;
+ struct led_ops *ops = led_get_ops(dev);
+ int half_period_us;
+
+ half_period_us = period_ms * 1000 / 2;
+
+ if (!sw_blink) {
+ int len = sizeof(struct led_sw_blink) +
+ strlen(CYCLIC_NAME_PREFIX) +
+ strlen(uc_plat->label) + 1;
+
+ sw_blink = calloc(1, len);
+ if (!sw_blink)
+ return -ENOMEM;
+
+ sw_blink->dev = dev;
+ sw_blink->state = LED_SW_BLINK_ST_DISABLED;
+ strcpy((char *)sw_blink->cyclic_name, CYCLIC_NAME_PREFIX);
+ strcat((char *)sw_blink->cyclic_name, uc_plat->label);
+
+ uc_plat->sw_blink = sw_blink;
+ }
+
+ if (sw_blink->state == LED_SW_BLINK_ST_DISABLED) {
+ cyclic_register(&sw_blink->cyclic, led_sw_blink,
+ half_period_us, sw_blink->cyclic_name);
+ } else {
+ sw_blink->cyclic.delay_us = half_period_us;
+ sw_blink->cyclic.start_time_us = timer_get_us();
+ }
+
+ 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);
+ struct led_sw_blink *sw_blink = uc_plat->sw_blink;
+
+ if (!sw_blink)
+ return false;
+
+ return 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);
+ struct led_sw_blink *sw_blink = uc_plat->sw_blink;
+
+ if (!sw_blink || sw_blink->state == LED_SW_BLINK_ST_DISABLED)
+ return false;
+
+ if (state == LEDST_BLINK) {
+ /* start blinking on next led_sw_blink() call */
+ sw_blink->state = LED_SW_BLINK_ST_OFF;
+ return true;
+ }
+
+ /* stop blinking */
+ uc_plat->sw_blink = NULL;
+ cyclic_unregister(&sw_blink->cyclic);
+ free(sw_blink);
+
+ return false;
+}