Add a driver for the SGMICRO SGM3140 Buck/Boost Charge Pump LED driver.
This device is controlled by two GPIO pins, one for enabling and the
second one for switching between torch and flash mode.
Signed-off-by: Luca Weiss <[email protected]>
---
Changes since v2:
- switch from of to fwnode API
drivers/leds/Kconfig | 8 +
drivers/leds/Makefile | 1 +
drivers/leds/leds-sgm3140.c | 320 ++++++++++++++++++++++++++++++++++++
3 files changed, 329 insertions(+)
create mode 100644 drivers/leds/leds-sgm3140.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 7599dbee8de13..e746c4429a288 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -871,6 +871,14 @@ config LEDS_IP30
To compile this driver as a module, choose M here: the module
will be called leds-ip30.
+config LEDS_SGM3140
+ tristate "LED support for the SGM3140"
+ depends on LEDS_CLASS_FLASH
+ depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
+ help
+ This option enables support for the SGM3140 500mA Buck/Boost Charge
+ Pump LED Driver.
+
comment "LED Triggers"
source "drivers/leds/trigger/Kconfig"
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index fd61421f7d405..f60ed0c09d4c9 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_LEDS_PWM) += leds-pwm.o
obj-$(CONFIG_LEDS_REGULATOR) += leds-regulator.o
obj-$(CONFIG_LEDS_S3C24XX) += leds-s3c24xx.o
obj-$(CONFIG_LEDS_SC27XX_BLTC) += leds-sc27xx-bltc.o
+obj-$(CONFIG_LEDS_SGM3140) += leds-sgm3140.o
obj-$(CONFIG_LEDS_SUNFIRE) += leds-sunfire.o
obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o
obj-$(CONFIG_LEDS_TCA6507) += leds-tca6507.o
diff --git a/drivers/leds/leds-sgm3140.c b/drivers/leds/leds-sgm3140.c
new file mode 100644
index 0000000000000..c494b934ae095
--- /dev/null
+++ b/drivers/leds/leds-sgm3140.c
@@ -0,0 +1,320 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2020 Luca Weiss <[email protected]>
+
+#include <linux/gpio/consumer.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/platform_device.h>
+
+#include <media/v4l2-flash-led-class.h>
+
+#define FLASH_TIMEOUT_DEFAULT 250000U /* 250ms */
+#define FLASH_MAX_TIMEOUT_DEFAULT 300000U /* 300ms */
+
+struct sgm3140 {
+ struct led_classdev_flash fled_cdev;
+ struct v4l2_flash *v4l2_flash;
+
+ struct timer_list powerdown_timer;
+
+ struct gpio_desc *flash_gpio;
+ struct gpio_desc *enable_gpio;
+ struct regulator *vin_regulator;
+
+ bool enabled;
+
+ /* current timeout in us */
+ u32 timeout;
+ /* maximum timeout in us */
+ u32 max_timeout;
+};
+
+static struct sgm3140 *flcdev_to_sgm3140(struct led_classdev_flash *flcdev)
+{
+ return container_of(flcdev, struct sgm3140, fled_cdev);
+}
+
+static int sgm3140_strobe_set(struct led_classdev_flash *fled_cdev, bool state)
+{
+ struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
+ int ret;
+
+ if (priv->enabled == state)
+ return 0;
+
+ if (state) {
+ ret = regulator_enable(priv->vin_regulator);
+ if (ret) {
+ dev_err(fled_cdev->led_cdev.dev,
+ "failed to enable regulator: %d\n", ret);
+ return ret;
+ }
+ gpiod_set_value_cansleep(priv->flash_gpio, 1);
+ gpiod_set_value_cansleep(priv->enable_gpio, 1);
+ mod_timer(&priv->powerdown_timer,
+ jiffies + usecs_to_jiffies(priv->timeout));
+ } else {
+ del_timer_sync(&priv->powerdown_timer);
+ gpiod_set_value_cansleep(priv->enable_gpio, 0);
+ gpiod_set_value_cansleep(priv->flash_gpio, 0);
+ ret = regulator_disable(priv->vin_regulator);
+ if (ret) {
+ dev_err(fled_cdev->led_cdev.dev,
+ "failed to disable regulator: %d\n", ret);
+ return ret;
+ }
+ }
+
+ priv->enabled = state;
+
+ return 0;
+}
+
+static int sgm3140_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
+{
+ struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
+
+ *state = timer_pending(&priv->powerdown_timer);
+
+ return 0;
+}
+
+static int sgm3140_timeout_set(struct led_classdev_flash *fled_cdev,
+ u32 timeout)
+{
+ struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
+
+ priv->timeout = timeout;
+
+ return 0;
+}
+
+static const struct led_flash_ops sgm3140_flash_ops = {
+ .strobe_set = sgm3140_strobe_set,
+ .strobe_get = sgm3140_strobe_get,
+ .timeout_set = sgm3140_timeout_set,
+};
+
+static int sgm3140_brightness_set(struct led_classdev *led_cdev,
+ enum led_brightness brightness)
+{
+ struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
+ struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
+ bool enable = brightness == LED_ON;
+ int ret;
+
+ if (priv->enabled == enable)
+ return 0;
+
+ if (enable) {
+ ret = regulator_enable(priv->vin_regulator);
+ if (ret) {
+ dev_err(led_cdev->dev,
+ "failed to enable regulator: %d\n", ret);
+ return ret;
+ }
+ gpiod_set_value_cansleep(priv->enable_gpio, 1);
+ } else {
+ gpiod_set_value_cansleep(priv->enable_gpio, 0);
+ ret = regulator_disable(priv->vin_regulator);
+ if (ret) {
+ dev_err(led_cdev->dev,
+ "failed to disable regulator: %d\n", ret);
+ return ret;
+ }
+ }
+
+ priv->enabled = enable;
+
+ return 0;
+}
+
+static void sgm3140_powerdown_timer(struct timer_list *t)
+{
+ struct sgm3140 *priv = from_timer(priv, t, powerdown_timer);
+
+ gpiod_set_value(priv->enable_gpio, 0);
+ gpiod_set_value(priv->flash_gpio, 0);
+ regulator_disable(priv->vin_regulator);
+
+ priv->enabled = false;
+}
+
+static void sgm3140_init_flash_timeout(struct sgm3140 *priv)
+{
+ struct led_classdev_flash *fled_cdev = &priv->fled_cdev;
+ struct led_flash_setting *s;
+
+ /* Init flash timeout setting */
+ s = &fled_cdev->timeout;
+ s->min = 1;
+ s->max = priv->max_timeout;
+ s->step = 1;
+ s->val = FLASH_TIMEOUT_DEFAULT;
+}
+
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
+ struct v4l2_flash_config *v4l2_sd_cfg)
+{
+ struct led_classdev *led_cdev = &priv->fled_cdev.led_cdev;
+ struct led_flash_setting *s;
+
+ strscpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name,
+ sizeof(v4l2_sd_cfg->dev_name));
+
+ /* Init flash intensity setting */
+ s = &v4l2_sd_cfg->intensity;
+ s->min = 0;
+ s->max = 1;
+ s->step = 1;
+ s->val = 1;
+}
+
+#else
+static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
+ struct v4l2_flash_config *v4l2_sd_cfg)
+{
+}
+#endif
+
+static int sgm3140_probe(struct platform_device *pdev)
+{
+ struct sgm3140 *priv;
+ struct led_classdev *led_cdev;
+ struct led_classdev_flash *fled_cdev;
+ struct led_init_data init_data = {};
+ struct fwnode_handle *child_node;
+ struct v4l2_flash_config v4l2_sd_cfg = {};
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->flash_gpio = devm_gpiod_get(&pdev->dev, "flash", GPIOD_OUT_LOW);
+ ret = PTR_ERR_OR_ZERO(priv->flash_gpio);
+ if (ret) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev,
+ "Failed to request flash gpio: %d\n", ret);
+ return ret;
+ }
+
+ priv->enable_gpio = devm_gpiod_get(&pdev->dev, "enable", GPIOD_OUT_LOW);
+ ret = PTR_ERR_OR_ZERO(priv->enable_gpio);
+ if (ret) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev,
+ "Failed to request enable gpio: %d\n", ret);
+ return ret;
+ }
+
+ priv->vin_regulator = devm_regulator_get(&pdev->dev, "vin");
+ ret = PTR_ERR_OR_ZERO(priv->vin_regulator);
+ if (ret) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev,
+ "Failed to request regulator: %d\n", ret);
+ return ret;
+ }
+
+ child_node = fwnode_get_next_available_child_node(pdev->dev.fwnode,
+ NULL);
+ if (!child_node) {
+ dev_err(&pdev->dev,
+ "No fwnode child node found for connected LED.\n");
+ return -EINVAL;
+ }
+
+ ret = fwnode_property_read_u32(child_node, "flash-max-timeout-us",
+ &priv->max_timeout);
+ if (ret) {
+ priv->max_timeout = FLASH_MAX_TIMEOUT_DEFAULT;
+ dev_warn(&pdev->dev,
+ "flash-max-timeout-us property missing\n");
+ }
+
+ /*
+ * Set default timeout to FLASH_DEFAULT_TIMEOUT except if max_timeout
+ * from DT is lower.
+ */
+ priv->timeout = min(priv->max_timeout, FLASH_TIMEOUT_DEFAULT);
+
+ timer_setup(&priv->powerdown_timer, sgm3140_powerdown_timer, 0);
+
+ fled_cdev = &priv->fled_cdev;
+ led_cdev = &fled_cdev->led_cdev;
+
+ fled_cdev->ops = &sgm3140_flash_ops;
+
+ led_cdev->brightness_set_blocking = sgm3140_brightness_set;
+ led_cdev->max_brightness = LED_ON;
+ led_cdev->flags |= LED_DEV_CAP_FLASH;
+
+ sgm3140_init_flash_timeout(priv);
+
+ init_data.fwnode = child_node;
+
+ platform_set_drvdata(pdev, priv);
+
+ /* Register in the LED subsystem */
+ ret = devm_led_classdev_flash_register_ext(&pdev->dev,
+ fled_cdev, &init_data);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to register flash device: %d\n",
+ ret);
+ goto err;
+ }
+
+ sgm3140_init_v4l2_flash_config(priv, &v4l2_sd_cfg);
+
+ /* Create V4L2 Flash subdev */
+ priv->v4l2_flash = v4l2_flash_init(&pdev->dev,
+ child_node,
+ fled_cdev, NULL,
+ &v4l2_sd_cfg);
+ if (IS_ERR(priv->v4l2_flash)) {
+ ret = PTR_ERR(priv->v4l2_flash);
+ goto err;
+ }
+
+ return ret;
+
+err:
+ fwnode_handle_put(child_node);
+ return ret;
+}
+
+static int sgm3140_remove(struct platform_device *pdev)
+{
+ struct sgm3140 *priv = platform_get_drvdata(pdev);
+
+ del_timer_sync(&priv->powerdown_timer);
+
+ v4l2_flash_release(priv->v4l2_flash);
+
+ return 0;
+}
+
+static const struct of_device_id sgm3140_dt_match[] = {
+ { .compatible = "sgmicro,sgm3140" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sgm3140_dt_match);
+
+static struct platform_driver sgm3140_driver = {
+ .probe = sgm3140_probe,
+ .remove = sgm3140_remove,
+ .driver = {
+ .name = "sgm3140",
+ .of_match_table = sgm3140_dt_match,
+ },
+};
+
+module_platform_driver(sgm3140_driver);
+
+MODULE_AUTHOR("Luca Weiss <[email protected]>");
+MODULE_DESCRIPTION("SG Micro SGM3140 charge pump led driver");
+MODULE_LICENSE("GPL v2");
--
2.26.1
Hi!
> Add a driver for the SGMICRO SGM3140 Buck/Boost Charge Pump LED driver.
>
> This device is controlled by two GPIO pins, one for enabling and the
> second one for switching between torch and flash mode.
>
> Signed-off-by: Luca Weiss <[email protected]>
Thanks, applied, but... I may remove it again.
> +++ b/drivers/leds/leds-sgm3140.c
> @@ -0,0 +1,320 @@
> +// SPDX-License-Identifier: GPL-2.0
Would you consider GPL-2+?
> +#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
> +static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
Ok.
> +static int sgm3140_probe(struct platform_device *pdev)
> +{
...
> + led_cdev->brightness_set_blocking = sgm3140_brightness_set;
> + led_cdev->max_brightness = LED_ON;
Don't do this, unless you really have 255 levels of brightness.
> + /* Create V4L2 Flash subdev */
> + priv->v4l2_flash = v4l2_flash_init(&pdev->dev,
> + child_node,
> + fled_cdev, NULL,
> + &v4l2_sd_cfg);
> + if (IS_ERR(priv->v4l2_flash)) {
Does this need some #ifdef guards?
> + ret = PTR_ERR(priv->v4l2_flash);
> + goto err;
> + }
> +
> + return ret;
Should this return 0?
> +err:
> + fwnode_handle_put(child_node);
> + return ret;
> +}
Does non-error path needs handle_put, too?
Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
On Montag, 27. April 2020 11:51:02 CEST Pavel Machek wrote:
> Hi!
>
> > Add a driver for the SGMICRO SGM3140 Buck/Boost Charge Pump LED driver.
> >
> > This device is controlled by two GPIO pins, one for enabling and the
> > second one for switching between torch and flash mode.
> >
> > Signed-off-by: Luca Weiss <[email protected]>
>
> Thanks, applied, but... I may remove it again.
>
> > +++ b/drivers/leds/leds-sgm3140.c
> > @@ -0,0 +1,320 @@
> > +// SPDX-License-Identifier: GPL-2.0
>
> Would you consider GPL-2+?
I don't really have a preference either way but GPL-2.0-or-later is fine for
me.
>
> > +#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
> > +static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
>
> Ok.
>
> > +static int sgm3140_probe(struct platform_device *pdev)
> > +{
>
> ...
>
> > + led_cdev->brightness_set_blocking = sgm3140_brightness_set;
> > + led_cdev->max_brightness = LED_ON;
>
> Don't do this, unless you really have 255 levels of brightness.
LED_ON is 1, so the brightness available is 0 - 1.
>
> > + /* Create V4L2 Flash subdev */
> > + priv->v4l2_flash = v4l2_flash_init(&pdev->dev,
> > + child_node,
> > + fled_cdev, NULL,
> > + &v4l2_sd_cfg);
> > + if (IS_ERR(priv->v4l2_flash)) {
>
> Does this need some #ifdef guards?
v4l2_flash_init has a NULL-returning version when CONFIG_V4L2_FLASH_LED_CLASS
is not defined (see https://elixir.bootlin.com/linux/latest/source/include/
media/v4l2-flash-led-class.h#L166 )
>
> > + ret = PTR_ERR(priv->v4l2_flash);
> > + goto err;
> > + }
> > +
> > + return ret;
>
> Should this return 0?
ret should be 0 here, so it shouldn't matter much.
>
> > +err:
> > + fwnode_handle_put(child_node);
> > + return ret;
> > +}
>
> Does non-error path needs handle_put, too?
I don't think so, I'm passing child_node to v4l2_flash_init which then saves
the pointer to v4l2_subdev->fwnode.
The devm_led_classdev_flash_register_ext function also seems to store the
pointer (led_cdev->dev->fwnode = init_data->fwnode; in
led_classdev_register_ext)
>
> Best regards,
>
Pavel
Regards,
Luca
Hi Luca,
On 4/27/20 9:49 PM, Luca Weiss wrote:
> On Montag, 27. April 2020 11:51:02 CEST Pavel Machek wrote:
>> Hi!
>>
>>> Add a driver for the SGMICRO SGM3140 Buck/Boost Charge Pump LED driver.
>>>
>>> This device is controlled by two GPIO pins, one for enabling and the
>>> second one for switching between torch and flash mode.
>>>
>>> Signed-off-by: Luca Weiss <[email protected]>
>>
>> Thanks, applied, but... I may remove it again.
>>
>>> +++ b/drivers/leds/leds-sgm3140.c
>>> @@ -0,0 +1,320 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>
>> Would you consider GPL-2+?
>
> I don't really have a preference either way but GPL-2.0-or-later is fine for
> me.
>
>>
>>> +#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
>>> +static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
>>
>> Ok.
>>
>>> +static int sgm3140_probe(struct platform_device *pdev)
>>> +{
>>
>> ...
>>
>>> + led_cdev->brightness_set_blocking = sgm3140_brightness_set;
>>> + led_cdev->max_brightness = LED_ON;
>>
>> Don't do this, unless you really have 255 levels of brightness.
>
> LED_ON is 1, so the brightness available is 0 - 1.
>
>>
>>> + /* Create V4L2 Flash subdev */
>>> + priv->v4l2_flash = v4l2_flash_init(&pdev->dev,
>>> + child_node,
>>> + fled_cdev, NULL,
>>> + &v4l2_sd_cfg);
>>> + if (IS_ERR(priv->v4l2_flash)) {
>>
>> Does this need some #ifdef guards?
>
> v4l2_flash_init has a NULL-returning version when CONFIG_V4L2_FLASH_LED_CLASS
> is not defined (see https://elixir.bootlin.com/linux/latest/source/include/
> media/v4l2-flash-led-class.h#L166 )
Correct.
>>
>>> + ret = PTR_ERR(priv->v4l2_flash);
>>> + goto err;
>>> + }
>>> +
>>> + return ret;
>>
>> Should this return 0?
>
> ret should be 0 here, so it shouldn't matter much.
>
>>
>>> +err:
>>> + fwnode_handle_put(child_node);
>>> + return ret;
>>> +}
>>
>> Does non-error path needs handle_put, too?
>
> I don't think so, I'm passing child_node to v4l2_flash_init which then saves
> the pointer to v4l2_subdev->fwnode.
>
> The devm_led_classdev_flash_register_ext function also seems to store the
> pointer (led_cdev->dev->fwnode = init_data->fwnode; in
> led_classdev_register_ext)
The node needs to be held only during parsing, so you
have to call fwnode_handle_put() for both paths.
--
Best regards,
Jacek Anaszewski