[PATCH v5 1/2] led: Implement software led blinking
Simon Glass
sjg at chromium.org
Sat Jul 13 17:13:40 CEST 2024
Hi Mikhail,
On Fri, 12 Jul 2024 at 06:25, Mikhail Kshevetskiy
<mikhail.kshevetskiy at iopsys.eu> wrote:
>
> 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 | 19 +++++--
> drivers/led/led_sw_blink.c | 106 +++++++++++++++++++++++++++++++++++++
> include/led.h | 17 ++++++
> 5 files changed, 154 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..4f5dd66765e 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 +72,12 @@ enum led_state_t led_get_state(struct udevice *dev)
> if (!ops->get_state)
> return -ENOSYS;
>
> +#ifdef CONFIG_LED_BLINK
It looks like you can use if (IS_ENABLED...) for that ^
> + if (IS_ENABLED(CONFIG_LED_SW_BLINK) &&
> + led_sw_is_blinking(dev))
> + return LEDST_BLINK;
> +#endif
> +
> return ops->get_state(dev);
> }
>
> @@ -76,10 +86,13 @@ 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) {
if (!name)
> + 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);
I think it would be OK to have a fixed-length name (say 20-30 chars)
and use snprintf()...would reduce the code size.
> + }
> +
> + 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);
drop ()
> +}
> +
> +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
>
Regards,
Simon
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