From: Bjorn Andersson <[email protected]>
Some LED controllers have support for autonomously controlling
brightness over time, according to some preprogrammed pattern or
function.
This adds a new optional operator that LED class drivers can implement
if they support such functionality as well as a new device attribute to
configure the pattern for a given LED.
Signed-off-by: Bjorn Andersson <[email protected]>
Signed-off-by: Baolin Wang <[email protected]>
---
Note: I removed the pattern repeat check and will get the repeat number by adding
one extra file named 'pattern_repeat' according to previous discussion.
---
Documentation/ABI/testing/sysfs-class-led | 16 ++++
drivers/leds/led-class.c | 127 +++++++++++++++++++++++++++++
include/linux/leds.h | 19 +++++
3 files changed, 162 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led
index 5f67f7a..fe90a12 100644
--- a/Documentation/ABI/testing/sysfs-class-led
+++ b/Documentation/ABI/testing/sysfs-class-led
@@ -61,3 +61,19 @@ Description:
gpio and backlight triggers. In case of the backlight trigger,
it is useful when driving a LED which is intended to indicate
a device in a standby like state.
+
+What: /sys/class/leds/<led>/pattern
+Date: June 2018
+KernelVersion: 4.18
+Description:
+ Specify a pattern for the LED, for LED hardware that support
+ altering the brightness as a function of time.
+
+ The pattern is given by a series of tuples, of brightness and
+ duration (ms). The LED is expected to traverse the series and
+ each brightness value for the specified duration.
+
+ As LED hardware might have different capabilities and precision
+ the requested pattern might be slighly adjusted by the driver
+ and the resulting pattern of such operation should be returned
+ when this file is read.
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 3c7e348..5ebdd83 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -74,6 +74,131 @@ static ssize_t max_brightness_show(struct device *dev,
}
static DEVICE_ATTR_RO(max_brightness);
+static ssize_t pattern_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_pattern *pattern;
+ size_t offset = 0;
+ int count, n, i;
+
+ if (!led_cdev->pattern_get)
+ return -EOPNOTSUPP;
+
+ pattern = led_cdev->pattern_get(led_cdev, &count);
+ if (IS_ERR_OR_NULL(pattern))
+ return PTR_ERR(pattern);
+
+ for (i = 0; i < count; i++) {
+ n = snprintf(buf + offset, PAGE_SIZE - offset, "%d %d",
+ pattern[i].brightness, pattern[i].delta_t);
+
+ if (offset + n >= PAGE_SIZE)
+ goto err_nospc;
+
+ offset += n;
+
+ if (i < count - 1)
+ buf[offset++] = ' ';
+ }
+
+ buf[offset++] = '\n';
+
+ kfree(pattern);
+ return offset;
+
+err_nospc:
+ kfree(pattern);
+ return -ENOSPC;
+}
+
+static ssize_t pattern_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct led_pattern *pattern = NULL;
+ unsigned long val;
+ char *sbegin;
+ char *elem;
+ char *s;
+ int ret, len = 0;
+ bool odd = true;
+
+ s = sbegin = kstrndup(buf, size, GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ /* Trim trailing newline */
+ s[strcspn(s, "\n")] = '\0';
+
+ /* If the remaining string is empty, clear the pattern */
+ if (!s[0]) {
+ ret = led_cdev->pattern_clear(led_cdev);
+ goto out;
+ }
+
+ pattern = kcalloc(size, sizeof(*pattern), GFP_KERNEL);
+ if (!pattern) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* Parse out the brightness & delta_t touples and check for repeat */
+ while ((elem = strsep(&s, " ")) != NULL) {
+ ret = kstrtoul(elem, 10, &val);
+ if (ret)
+ goto out;
+
+ if (odd) {
+ pattern[len].brightness = val;
+ } else {
+ /* Ensure we don't have any delta_t == 0 */
+ if (!val) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ pattern[len].delta_t = val;
+ len++;
+ }
+
+ odd = !odd;
+ }
+
+ /*
+ * Fail if we didn't find any data points or last data point was partial
+ */
+ if (!len || !odd) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = led_cdev->pattern_set(led_cdev, pattern, len);
+
+out:
+ kfree(pattern);
+ kfree(sbegin);
+ return ret < 0 ? ret : size;
+}
+static DEVICE_ATTR_RW(pattern);
+
+static umode_t led_class_attrs_mode(struct kobject *kobj,
+ struct attribute *attr, int index)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+ if (attr == &dev_attr_brightness.attr)
+ return attr->mode;
+ if (attr == &dev_attr_max_brightness.attr)
+ return attr->mode;
+ if (attr == &dev_attr_pattern.attr && led_cdev->pattern_set)
+ return attr->mode;
+
+ return 0;
+}
+
#ifdef CONFIG_LEDS_TRIGGERS
static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
static struct attribute *led_trigger_attrs[] = {
@@ -88,11 +213,13 @@ static ssize_t max_brightness_show(struct device *dev,
static struct attribute *led_class_attrs[] = {
&dev_attr_brightness.attr,
&dev_attr_max_brightness.attr,
+ &dev_attr_pattern.attr,
NULL,
};
static const struct attribute_group led_group = {
.attrs = led_class_attrs,
+ .is_visible = led_class_attrs_mode,
};
static const struct attribute_group *led_groups[] = {
diff --git a/include/linux/leds.h b/include/linux/leds.h
index b7e8255..acdbb2f 100644
--- a/include/linux/leds.h
+++ b/include/linux/leds.h
@@ -22,6 +22,7 @@
#include <linux/workqueue.h>
struct device;
+struct led_pattern;
/*
* LED Core
*/
@@ -88,6 +89,14 @@ struct led_classdev {
unsigned long *delay_on,
unsigned long *delay_off);
+ int (*pattern_set)(struct led_classdev *led_cdev,
+ struct led_pattern *pattern, int len);
+
+ int (*pattern_clear)(struct led_classdev *led_cdev);
+
+ struct led_pattern *(*pattern_get)(struct led_classdev *led_cdev,
+ int *len);
+
struct device *dev;
const struct attribute_group **groups;
@@ -446,4 +455,14 @@ static inline void led_classdev_notify_brightness_hw_changed(
struct led_classdev *led_cdev, enum led_brightness brightness) { }
#endif
+/**
+ * struct led_pattern - brigheness value in a pattern
+ * @delta_t: delay until next entry, in milliseconds
+ * @brightness: brightness at time = 0
+ */
+struct led_pattern {
+ int delta_t;
+ int brightness;
+};
+
#endif /* __LINUX_LEDS_H_INCLUDED */
--
1.7.9.5
This patch implements the 'pattern_set', 'pattern_get' and 'pattern_clear'
interfaces to support SC27XX LED breathing mode.
Signed-off-by: Baolin Wang <[email protected]>
---
drivers/leds/leds-sc27xx-bltc.c | 160 +++++++++++++++++++++++++++++++++++++++
1 file changed, 160 insertions(+)
diff --git a/drivers/leds/leds-sc27xx-bltc.c b/drivers/leds/leds-sc27xx-bltc.c
index 9d9b7aa..898f92d 100644
--- a/drivers/leds/leds-sc27xx-bltc.c
+++ b/drivers/leds/leds-sc27xx-bltc.c
@@ -6,6 +6,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
+#include <linux/slab.h>
#include <uapi/linux/uleds.h>
/* PMIC global control register definition */
@@ -32,8 +33,13 @@
#define SC27XX_DUTY_MASK GENMASK(15, 0)
#define SC27XX_MOD_MASK GENMASK(7, 0)
+#define SC27XX_CURVE_SHIFT 8
+#define SC27XX_CURVE_L_MASK GENMASK(7, 0)
+#define SC27XX_CURVE_H_MASK GENMASK(15, 8)
+
#define SC27XX_LEDS_OFFSET 0x10
#define SC27XX_LEDS_MAX 3
+#define SC27XX_LEDS_PATTERN_CNT 4
struct sc27xx_led {
char name[LED_MAX_NAME_SIZE];
@@ -122,6 +128,157 @@ static int sc27xx_led_set(struct led_classdev *ldev, enum led_brightness value)
return err;
}
+static int sc27xx_led_pattern_clear(struct led_classdev *ldev)
+{
+ struct sc27xx_led *leds = to_sc27xx_led(ldev);
+ struct regmap *regmap = leds->priv->regmap;
+ u32 base = sc27xx_led_get_offset(leds);
+ u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL;
+ u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line;
+ int err;
+
+ mutex_lock(&leds->priv->lock);
+
+ /* Reset the rise, high, fall and low time to zero. */
+ regmap_write(regmap, base + SC27XX_LEDS_CURVE0, 0);
+ regmap_write(regmap, base + SC27XX_LEDS_CURVE1, 0);
+
+ err = regmap_update_bits(regmap, ctrl_base,
+ (SC27XX_LED_RUN | SC27XX_LED_TYPE) << ctrl_shift, 0);
+
+ mutex_unlock(&leds->priv->lock);
+
+ return err;
+}
+
+static int sc27xx_led_pattern_set(struct led_classdev *ldev,
+ struct led_pattern *pattern,
+ int len)
+{
+ struct sc27xx_led *leds = to_sc27xx_led(ldev);
+ u32 base = sc27xx_led_get_offset(leds);
+ u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL;
+ u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line;
+ struct regmap *regmap = leds->priv->regmap;
+ int err;
+
+ /*
+ * Must contain 4 patterns to configure the rise time, high time, fall
+ * time and low time to enable the breathing mode.
+ */
+ if (len != SC27XX_LEDS_PATTERN_CNT)
+ return -EINVAL;
+
+ mutex_lock(&leds->priv->lock);
+
+ err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE0,
+ SC27XX_CURVE_L_MASK, pattern[0].delta_t);
+ if (err)
+ goto out;
+
+ err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE1,
+ SC27XX_CURVE_L_MASK, pattern[1].delta_t);
+ if (err)
+ goto out;
+
+ err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE0,
+ SC27XX_CURVE_H_MASK,
+ pattern[2].delta_t << SC27XX_CURVE_SHIFT);
+ if (err)
+ goto out;
+
+
+ err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE1,
+ SC27XX_CURVE_H_MASK,
+ pattern[3].delta_t << SC27XX_CURVE_SHIFT);
+ if (err)
+ goto out;
+
+
+ err = regmap_update_bits(regmap, base + SC27XX_LEDS_DUTY,
+ SC27XX_DUTY_MASK,
+ (pattern[0].brightness << SC27XX_DUTY_SHIFT) |
+ SC27XX_MOD_MASK);
+ if (err)
+ goto out;
+
+ /* Enable the LED breathing mode */
+ err = regmap_update_bits(regmap, ctrl_base,
+ SC27XX_LED_RUN << ctrl_shift,
+ SC27XX_LED_RUN << ctrl_shift);
+
+out:
+ mutex_unlock(&leds->priv->lock);
+
+ return err;
+}
+
+static struct led_pattern *sc27xx_led_pattern_get(struct led_classdev *ldev,
+ int *len)
+{
+ struct sc27xx_led *leds = to_sc27xx_led(ldev);
+ u32 base = sc27xx_led_get_offset(leds);
+ struct regmap *regmap = leds->priv->regmap;
+ struct led_pattern *pattern;
+ int i, err;
+ u32 val;
+
+ /*
+ * Must allocate 4 patterns to show the rise time, high time, fall time
+ * and low time.
+ */
+ pattern = kcalloc(SC27XX_LEDS_PATTERN_CNT, sizeof(*pattern),
+ GFP_KERNEL);
+ if (!pattern)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_lock(&leds->priv->lock);
+
+ err = regmap_read(regmap, base + SC27XX_LEDS_CURVE0, &val);
+ if (err)
+ goto out;
+
+ pattern[0].delta_t = val & SC27XX_CURVE_L_MASK;
+
+ err = regmap_read(regmap, base + SC27XX_LEDS_CURVE1, &val);
+ if (err)
+ goto out;
+
+ pattern[1].delta_t = val & SC27XX_CURVE_L_MASK;
+
+ err = regmap_read(regmap, base + SC27XX_LEDS_CURVE0, &val);
+ if (err)
+ goto out;
+
+ pattern[2].delta_t = (val & SC27XX_CURVE_H_MASK) >> SC27XX_CURVE_SHIFT;
+
+ err = regmap_read(regmap, base + SC27XX_LEDS_CURVE1, &val);
+ if (err)
+ goto out;
+
+ pattern[3].delta_t = (val & SC27XX_CURVE_H_MASK) >> SC27XX_CURVE_SHIFT;
+
+ err = regmap_read(regmap, base + SC27XX_LEDS_DUTY, &val);
+ if (err)
+ goto out;
+
+ mutex_unlock(&leds->priv->lock);
+
+ val = (val & SC27XX_DUTY_MASK) >> SC27XX_DUTY_SHIFT;
+ for (i = 0; i < SC27XX_LEDS_PATTERN_CNT; i++)
+ pattern[i].brightness = val;
+
+ *len = SC27XX_LEDS_PATTERN_CNT;
+
+ return pattern;
+
+out:
+ mutex_unlock(&leds->priv->lock);
+ kfree(pattern);
+
+ return ERR_PTR(err);
+}
+
static int sc27xx_led_register(struct device *dev, struct sc27xx_led_priv *priv)
{
int i, err;
@@ -140,6 +297,9 @@ static int sc27xx_led_register(struct device *dev, struct sc27xx_led_priv *priv)
led->priv = priv;
led->ldev.name = led->name;
led->ldev.brightness_set_blocking = sc27xx_led_set;
+ led->ldev.pattern_set = sc27xx_led_pattern_set;
+ led->ldev.pattern_get = sc27xx_led_pattern_get;
+ led->ldev.pattern_clear = sc27xx_led_pattern_clear;
err = devm_led_classdev_register(dev, &led->ldev);
if (err)
--
1.7.9.5
On Mon 2018-06-25 13:03:19, Baolin Wang wrote:
> From: Bjorn Andersson <[email protected]>
>
> Some LED controllers have support for autonomously controlling
> brightness over time, according to some preprogrammed pattern or
> function.
>
> This adds a new optional operator that LED class drivers can implement
> if they support such functionality as well as a new device attribute to
> configure the pattern for a given LED.
Thanks for doing this!
> index 5f67f7a..fe90a12 100644
> --- a/Documentation/ABI/testing/sysfs-class-led
> +++ b/Documentation/ABI/testing/sysfs-class-led
> @@ -61,3 +61,19 @@ Description:
> gpio and backlight triggers. In case of the backlight trigger,
> it is useful when driving a LED which is intended to indicate
> a device in a standby like state.
> +
> +What: /sys/class/leds/<led>/pattern
> +Date: June 2018
> +KernelVersion: 4.18
> +Description:
> + Specify a pattern for the LED, for LED hardware that support
> + altering the brightness as a function of time.
> +
> + The pattern is given by a series of tuples, of brightness and
> + duration (ms). The LED is expected to traverse the series and
> + each brightness value for the specified duration.
> +
> + As LED hardware might have different capabilities and precision
> + the requested pattern might be slighly adjusted by the driver
> + and the resulting pattern of such operation should be returned
> + when this file is read.
I'd add "Duration of 0 means brightness should immediately change to
new value."
> + struct led_classdev *led_cdev = dev_get_drvdata(dev);
> + struct led_pattern *pattern = NULL;
> + unsigned long val;
> + char *sbegin;
> + char *elem;
> + char *s;
> + int ret, len = 0;
> + bool odd = true;
> +
> + s = sbegin = kstrndup(buf, size, GFP_KERNEL);
> + if (!s)
> + return -ENOMEM;
> +
> + /* Trim trailing newline */
> + s[strcspn(s, "\n")] = '\0';
Is substring function best to use here? Will it do the right thing
when \n is not present?
> + /* If the remaining string is empty, clear the pattern */
> + if (!s[0]) {
> + ret = led_cdev->pattern_clear(led_cdev);
> + goto out;
> + }
> +
> + pattern = kcalloc(size, sizeof(*pattern), GFP_KERNEL);
> + if (!pattern) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + /* Parse out the brightness & delta_t touples and check for repeat */
> + while ((elem = strsep(&s, " ")) != NULL) {
> + ret = kstrtoul(elem, 10, &val);
> + if (ret)
> + goto out;
> +
> + if (odd) {
> + pattern[len].brightness = val;
> + } else {
> + /* Ensure we don't have any delta_t == 0 */
> + if (!val) {
> + ret = -EINVAL;
> + goto out;
> + }
I believe we should support delta_t of 0 for "change immediately".
Thanks,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
Hi Pavel,
On 25 June 2018 at 20:18, Pavel Machek <[email protected]> wrote:
> On Mon 2018-06-25 13:03:19, Baolin Wang wrote:
>> From: Bjorn Andersson <[email protected]>
>>
>> Some LED controllers have support for autonomously controlling
>> brightness over time, according to some preprogrammed pattern or
>> function.
>>
>> This adds a new optional operator that LED class drivers can implement
>> if they support such functionality as well as a new device attribute to
>> configure the pattern for a given LED.
>
> Thanks for doing this!
>
>> index 5f67f7a..fe90a12 100644
>> --- a/Documentation/ABI/testing/sysfs-class-led
>> +++ b/Documentation/ABI/testing/sysfs-class-led
>> @@ -61,3 +61,19 @@ Description:
>> gpio and backlight triggers. In case of the backlight trigger,
>> it is useful when driving a LED which is intended to indicate
>> a device in a standby like state.
>> +
>> +What: /sys/class/leds/<led>/pattern
>> +Date: June 2018
>> +KernelVersion: 4.18
>> +Description:
>> + Specify a pattern for the LED, for LED hardware that support
>> + altering the brightness as a function of time.
>> +
>> + The pattern is given by a series of tuples, of brightness and
>> + duration (ms). The LED is expected to traverse the series and
>> + each brightness value for the specified duration.
>> +
>> + As LED hardware might have different capabilities and precision
>> + the requested pattern might be slighly adjusted by the driver
>> + and the resulting pattern of such operation should be returned
>> + when this file is read.
>
> I'd add "Duration of 0 means brightness should immediately change to
> new value."
Sure.
>
>> + struct led_classdev *led_cdev = dev_get_drvdata(dev);
>> + struct led_pattern *pattern = NULL;
>> + unsigned long val;
>> + char *sbegin;
>> + char *elem;
>> + char *s;
>> + int ret, len = 0;
>> + bool odd = true;
>> +
>> + s = sbegin = kstrndup(buf, size, GFP_KERNEL);
>> + if (!s)
>> + return -ENOMEM;
>> +
>> + /* Trim trailing newline */
>> + s[strcspn(s, "\n")] = '\0';
>
> Is substring function best to use here? Will it do the right thing
> when \n is not present?
We always have a '\n' to present the end of the string passed from
userspace. Or anything I missed here?
>
>> + /* If the remaining string is empty, clear the pattern */
>> + if (!s[0]) {
>> + ret = led_cdev->pattern_clear(led_cdev);
>> + goto out;
>> + }
>> +
>> + pattern = kcalloc(size, sizeof(*pattern), GFP_KERNEL);
>> + if (!pattern) {
>> + ret = -ENOMEM;
>> + goto out;
>> + }
>> +
>> + /* Parse out the brightness & delta_t touples and check for repeat */
>> + while ((elem = strsep(&s, " ")) != NULL) {
>> + ret = kstrtoul(elem, 10, &val);
>> + if (ret)
>> + goto out;
>> +
>> + if (odd) {
>> + pattern[len].brightness = val;
>> + } else {
>> + /* Ensure we don't have any delta_t == 0 */
>> + if (!val) {
>> + ret = -EINVAL;
>> + goto out;
>> + }
>
> I believe we should support delta_t of 0 for "change immediately".
OK. Thanks for your comments.
--
Baolin Wang
Best Regards