Re: [PATCH v4 3/5] pwm-backlight: add support for PWM delays proprieties.

Hi,

2017-07-26 19:01 GMT+02:00 Jingoo Han [off-list ref]:

On Monday, July 24, 2017 11:22 AM, Daniel Thompson wrote:

quoted

On 21/07/17 11:48, Enric Balletbo i Serra wrote:

quoted

Some panels (i.e. N116BGE-L41), in their power sequence specifications,
request a delay between set the PWM signal and enable the backlight and
between clear the PWM signal and disable the backlight. Add support for
the new post-pwm-on-delay-ms and pwm-off-delay-ms proprieties to meet
the timings.

Signed-off-by: Enric Balletbo i Serra <redacted>

Acked-by: Daniel Thompson <redacted>

Acked-by: Jingoo Han <jingoohan1@gmail.com>

A lot of time has passed since these patches received the acks but I'm
still without seeing the patches in linux-next. There is some action I
need to do ? (rebase?). I'd really like to see those to land in next
merge window if all is ok.

Thanks,
 Enric

Best regards,
Jingoo Han

quoted

quoted

---
Changes since v3:
  - Use two named members instead of pwm_delay[] (Daniel and Pavel)
  - Use msleep instead of usleep_range. (Pavel)
Changes since v2:
  - Move the pwm/enable sequence to another patch (Thierry Reding)
Changes since v1:
  - As suggested by Daniel Thompson
    - Do not assume power-on delay and power-off delay will be the same
  - Move the check of dt property to the parse dt function.

  drivers/video/backlight/pwm_bl.c | 19 +++++++++++++++++++
  include/linux/pwm_backlight.h    |  2 ++
  2 files changed, 21 insertions(+)

diff --git a/drivers/video/backlight/pwm_bl.c

b/drivers/video/backlight/pwm_bl.c

quoted

index 909a686..6cf6109 100644

--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c

@@ -10,6 +10,7 @@
   * published by the Free Software Foundation.
   */

+#include <linux/delay.h>
  #include <linux/gpio/consumer.h>
  #include <linux/gpio.h>
  #include <linux/module.h>

@@ -35,6 +36,8 @@ struct pwm_bl_data {
    struct gpio_desc        *enable_gpio;
    unsigned int            scale;
    bool                    legacy;
+   unsigned int            post_pwm_on_delay;
+   unsigned int            pwm_off_delay;
    int                     (*notify)(struct device *,
                                      int brightness);
    void                    (*notify_after)(struct device *,

@@ -56,6 +59,9 @@ static void pwm_backlight_power_on(struct pwm_bl_data

*pb, int brightness)

quoted

    pwm_enable(pb->pwm);

+   if (pb->post_pwm_on_delay)
+           msleep(pb->post_pwm_on_delay);
+
    if (pb->enable_gpio)
            gpiod_set_value_cansleep(pb->enable_gpio, 1);

@@ -70,6 +76,9 @@ static void pwm_backlight_power_off(struct pwm_bl_data

*pb)

quoted

    if (pb->enable_gpio)
            gpiod_set_value_cansleep(pb->enable_gpio, 0);

+   if (pb->pwm_off_delay)
+           msleep(pb->pwm_off_delay);
+
    pwm_config(pb->pwm, 0, pb->period);
    pwm_disable(pb->pwm);

@@ -175,6 +184,14 @@ static int pwm_backlight_parse_dt(struct device

*dev,

quoted

            data->max_brightness--;
    }

+   /*
+    * These values are optional and set as 0 by default, the out

values

quoted

+    * are modified only if a valid u32 value can be decoded.
+    */
+   of_property_read_u32(node, "post-pwm-on-delay-ms",
+                        &data->post_pwm_on_delay);
+   of_property_read_u32(node, "pwm-off-delay-ms", &data-
pwm_off_delay);
+
    data->enable_gpio = -EINVAL;
    return 0;
  }

@@ -273,6 +290,8 @@ static int pwm_backlight_probe(struct

platform_device *pdev)

quoted

    pb->exit = data->exit;
    pb->dev = &pdev->dev;
    pb->enabled = false;
+   pb->post_pwm_on_delay = data->post_pwm_on_delay;
+   pb->pwm_off_delay = data->pwm_off_delay;

    pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
                                              GPIOD_ASIS);

diff --git a/include/linux/pwm_backlight.h

b/include/linux/pwm_backlight.h

quoted

index efdd922..62f59c4 100644

--- a/include/linux/pwm_backlight.h
+++ b/include/linux/pwm_backlight.h

@@ -13,6 +13,8 @@ struct platform_pwm_backlight_data {
    unsigned int lth_brightness;
    unsigned int pwm_period_ns;
    unsigned int *levels;
+   unsigned int post_pwm_on_delay;
+   unsigned int pwm_off_delay;
    /* TODO remove once all users are switched to gpiod_* API */
    int enable_gpio;
    int (*init)(struct device *dev);