From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fVxHb-0005ra-3w for barebox@lists.infradead.org; Thu, 21 Jun 2018 10:58:29 +0000 Date: Thu, 21 Jun 2018 12:57:31 +0200 From: Sascha Hauer Message-ID: <20180621105731.ulu247tcj7xmwofd@pengutronix.de> References: <20180620094749.1804-1-l.stach@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180620094749.1804-1-l.stach@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH v2] video: backlight: add slew time parameter To: Lucas Stach Cc: barebox@lists.infradead.org On Wed, Jun 20, 2018 at 11:47:49AM +0200, Lucas Stach wrote: > Currently the backlight implementation stretches a brightness change over > a period of 100ms. While this is a fine default for PWM backlights, a user > might wish to change this slew time to meet other constraints or even > completely disable it for some backlight devices. > > Add a parameter and provide the default value from the backlight device. > > Signed-off-by: Lucas Stach > --- > v2: rename variable and dev param to include unit Applied, thanks Sascha > --- > drivers/video/backlight-pwm.c | 1 + > drivers/video/backlight.c | 14 ++++++++++++-- > include/video/backlight.h | 1 + > 3 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/video/backlight-pwm.c b/drivers/video/backlight-pwm.c > index ec35bd1bc039..997235a74a30 100644 > --- a/drivers/video/backlight-pwm.c > +++ b/drivers/video/backlight-pwm.c > @@ -206,6 +206,7 @@ static int backlight_pwm_of_probe(struct device_d *dev) > > pwm_backlight->period = pwm_get_period(pwm_backlight->pwm); > > + pwm_backlight->backlight.slew_time_ms = 100; > pwm_backlight->backlight.brightness_set = backlight_pwm_set; > pwm_backlight->backlight.node = dev->device_node; > > diff --git a/drivers/video/backlight.c b/drivers/video/backlight.c > index 09c0e47af6fb..30d52fcb685b 100644 > --- a/drivers/video/backlight.c > +++ b/drivers/video/backlight.c > @@ -15,6 +15,15 @@ int backlight_set_brightness(struct backlight_device *bl, int brightness) > if (brightness == bl->brightness_cur) > return 0; > > + if (!bl->slew_time_ms) { > + ret = bl->brightness_set(bl, brightness); > + if (ret) > + return ret; > + > + bl->brightness_cur = bl->brightness = brightness; > + return 0; > + } > + > if (brightness > bl->brightness_cur) > step = 1; > else > @@ -34,10 +43,9 @@ int backlight_set_brightness(struct backlight_device *bl, int brightness) > if (i == brightness) > break; > > - udelay(100000 / num_steps); > + udelay(bl->slew_time_ms * 1000 / num_steps); > } > > - > bl->brightness_cur = bl->brightness = brightness; > > return ret; > @@ -72,6 +80,8 @@ int backlight_register(struct backlight_device *bl) > > dev_add_param_uint32(&bl->dev, "brightness", backlight_brightness_set, > NULL, &bl->brightness, "%d", bl); > + dev_add_param_uint32(&bl->dev, "slew_time_ms", NULL, NULL, > + &bl->slew_time_ms, "%d", NULL); > > list_add_tail(&bl->list, &backlights); > > diff --git a/include/video/backlight.h b/include/video/backlight.h > index 8dc49dc113e3..afa384cc9adf 100644 > --- a/include/video/backlight.h > +++ b/include/video/backlight.h > @@ -7,6 +7,7 @@ struct backlight_device { > int brightness_cur; > int brightness_max; > int brightness_default; > + int slew_time_ms; /* time to stretch brightness changes */ > int (*brightness_set)(struct backlight_device *, int brightness); > struct list_head list; > struct device_d dev; > -- > 2.17.1 > > > _______________________________________________ > barebox mailing list > barebox@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/barebox > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox