[PATCH v4 1/2] led: Implement software led blinking
Mikhail Kshevetskiy
mikhail.kshevetskiy at iopsys.eu
Fri Jul 5 14:10:22 CEST 2024
From: Michael Polyntsov <michael.polyntsov at 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.
Signed-off-by: Michael Polyntsov <michael.polyntsov at iopsys.eu>
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy at iopsys.eu>
---
drivers/led/Kconfig | 14 +++++
drivers/led/Makefile | 1 +
drivers/led/led-uclass.c | 17 ++++--
drivers/led/led_sw_blink.c | 106 +++++++++++++++++++++++++++++++++++++
include/led.h | 17 ++++++
5 files changed, 152 insertions(+), 3 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 at 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..03907a12407 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);
}
@@ -76,10 +84,13 @@ 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)
+ return ops->set_period(dev, period_ms);
+
+ if (IS_ENABLED(CONFIG_LED_SW_BLINK))
+ return led_sw_set_period(dev, period_ms);
- return ops->set_period(dev, period_ms);
+ return -ENOSYS;
}
#endif
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 at 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
--
2.39.2
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