Luca
On 3/9/20 3:35 PM, Luca Weiss wrote:
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.
How does one enable torch and one enable flash?
Is the flash-gpio control this or does the enable-gpio enable the flash?
The DT binding did not indicate what the GPIOs are really going to control.
Signed-off-by: Luca Weiss <luca@xxxxxxxxx>
---
Changes since RFC:
- address review comments from Jacek Anaszewski:
- implement strobe_get op
- implement timeout_set op
- init v4l2_sd_cfg variable
- remove init_data.devicename assignemnt
- use devm_ version of led_classdev_flash_register_ext
- release child_node in case of success
drivers/leds/Kconfig | 9 ++
drivers/leds/Makefile | 1 +
drivers/leds/leds-sgm3140.c | 260 ++++++++++++++++++++++++++++++++++++
3 files changed, 270 insertions(+)
create mode 100644 drivers/leds/leds-sgm3140.c
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 4b68520ac251..9206fc66799d 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -836,6 +836,15 @@ config LEDS_LM36274
Say Y to enable the LM36274 LED driver for TI LMU devices.
This supports the LED device LM36274.
+config LEDS_SGM3140
+ tristate "LED support for the SGM3140"
+ depends on LEDS_CLASS_FLASH
+ depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
What is the purpose of this? Enable if V4L2_FLASH_LED_CLASS is enabled
or if it is not enabled?
Seems to be a do nothing dependency in the Kconfig
+ depends on OF
+ 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 2da39e896ce8..38d57dd53e4b 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -85,6 +85,7 @@ obj-$(CONFIG_LEDS_LM3601X) += leds-lm3601x.o
obj-$(CONFIG_LEDS_TI_LMU_COMMON) += leds-ti-lmu-common.o
obj-$(CONFIG_LEDS_LM3697) += leds-lm3697.o
obj-$(CONFIG_LEDS_LM36274) += leds-lm36274.o
+obj-$(CONFIG_LEDS_SGM3140) += leds-sgm3140.o
# LED SPI Drivers
obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o
diff --git a/drivers/leds/leds-sgm3140.c b/drivers/leds/leds-sgm3140.c
new file mode 100644
index 000000000000..357f4cbb279a
--- /dev/null
+++ b/drivers/leds/leds-sgm3140.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2020 Luca Weiss <luca@xxxxxxxxx>
+
+#include <linux/gpio/consumer.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include <media/v4l2-flash-led-class.h>
+
+#define FLASH_TIMEOUT_DEFAULT 250000 /* 250ms */
+#define FLASH_MAX_TIMEOUT_DEFAULT 300000 /* 300ms */
+
+struct sgm3140 {
+ struct gpio_desc *flash_gpio;
+ struct gpio_desc *enable_gpio;
+
+ /* current timeout in us */
+ u32 timeout;
+ /* maximum timeout in us */
+ u32 max_timeout;
+
+ struct led_classdev_flash fled_cdev;
+ struct v4l2_flash *v4l2_flash;
+
+ struct timer_list powerdown_timer;
+};
+
+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);
+
+ if (state) {
+ 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 {
+ gpiod_set_value_cansleep(priv->enable_gpio, 0);
+ gpiod_set_value_cansleep(priv->flash_gpio, 0);
+ del_timer_sync(&priv->powerdown_timer);
+ }
+
+ 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;
+}
+
+struct led_flash_ops sgm3140_flash_ops = {
+ .strobe_set = sgm3140_strobe_set,
+ .strobe_get = sgm3140_strobe_get,
+ .timeout_set = sgm3140_timeout_set,
+};
+
+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);
+
+ if (brightness == LED_OFF)
+ gpiod_set_value_cansleep(priv->enable_gpio, 0);
+ else
+ gpiod_set_value_cansleep(priv->enable_gpio, 1);
+
+ return 0;
+}
+
+static void sgm3140_powerdown_timer(struct timer_list *t)
+{
+ struct sgm3140 *priv = from_timer(priv, t, powerdown_timer);
+
+ gpiod_set_value_cansleep(priv->enable_gpio, 0);
+ gpiod_set_value_cansleep(priv->flash_gpio, 0);
+}
+
+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;
+
+ strlcpy(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 device_node *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;
+ }
+
+ child_node = of_get_next_available_child(pdev->dev.of_node, NULL);
Please use the device_property api's to retrieve DT settings.
+ if (!child_node) {
+ dev_err(&pdev->dev, "No DT child node found for connected LED.\n");
+ return -EINVAL;
+ }
+
+
+ ret = of_property_read_u32(child_node, "flash-max-timeout-us",
+ &priv->max_timeout);
Please use the device_property api's to retrieve DT settings. Then
there is no need to release the "of" child node.
+ if (ret < 0) {
if (ret)
+ priv->max_timeout = FLASH_MAX_TIMEOUT_DEFAULT;
+ dev_warn(&pdev->dev, "flash-max-timeout-us DT property missing\n");
+ }
+
+ /*
+ * Set default timeout to FLASH_DEFAULT_TIMEOUT except if max_timeout
+ * from DT is lower.
+ */
+ priv->timeout = min(priv->max_timeout, (u32)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 = of_fwnode_handle(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 < 0) {
+ 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, of_fwnode_handle(child_node),
+ fled_cdev, NULL,
+ &v4l2_sd_cfg);
+ if (IS_ERR(priv->v4l2_flash)) {
+ ret = PTR_ERR(priv->v4l2_flash);
+ goto err;
Do you need to jump here? This should just fall out and go through err
anyway.
Dan
