From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4407C10F14 for ; Thu, 3 Oct 2019 11:47:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68E2E2070B for ; Thu, 3 Oct 2019 11:47:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570103261; bh=gjF+Beu9cVE7QyxON52ocEaaf6UCJYqYDNkFZGF0kpU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=udq9gXW5ekOYBvyCJgk64Dh2nwTbA18ErJ24dxTgTnxNPfXQjTWb7dVbPUGZZ1seL n5QVCicgQq7KHYyHAkdnTTnMKhaNZEa1+gXGleE9HkRDgLssB8Bglz7ZBu5jJyPh7V ogE7frO0z4h0519LVSuopm6uuPXDj8Sks3/l27rk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730256AbfJCLrl (ORCPT ); Thu, 3 Oct 2019 07:47:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:35006 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725827AbfJCLrk (ORCPT ); Thu, 3 Oct 2019 07:47:40 -0400 Received: from earth.universe (dyndsl-037-138-174-173.ewe-ip-backbone.de [37.138.174.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 39C7B2086A; Thu, 3 Oct 2019 11:47:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570103259; bh=gjF+Beu9cVE7QyxON52ocEaaf6UCJYqYDNkFZGF0kpU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=B5+4uathTZgUBWwoMwRo0uKanKIL2bOTtJFzQgJEYAcj1SoRrqO8DsUk5iYnV4ToO N5OvBSs6m7bLw8EzfIVFNWlW3c0IlgICEb880+CLdGeOmIhJbuiRekWiWYJyGQptOV TwugluC14UmIXQrkrt9QEaes7DKAjXTh0OaAGnL8= Received: by earth.universe (Postfix, from userid 1000) id 4654A3C0CA1; Thu, 3 Oct 2019 13:47:35 +0200 (CEST) Date: Thu, 3 Oct 2019 13:47:35 +0200 From: Sebastian Reichel To: Jean-Jacques Hiblot Cc: jacek.anaszewski@gmail.com, pavel@ucw.cz, robh+dt@kernel.org, mark.rutland@arm.com, lee.jones@linaro.org, daniel.thompson@linaro.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, tomi.valkeinen@ti.com, dmurphy@ti.com, linux-leds@vger.kernel.org Subject: Re: [PATCH v8 5/5] backlight: add led-backlight driver Message-ID: <20191003114735.byayntpe35qqrjeu@earth.universe> References: <20191003082812.28491-1-jjhiblot@ti.com> <20191003082812.28491-6-jjhiblot@ti.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="3lt566epwms7icad" Content-Disposition: inline In-Reply-To: <20191003082812.28491-6-jjhiblot@ti.com> User-Agent: NeoMutt/20180716 Sender: linux-leds-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org --3lt566epwms7icad Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Thu, Oct 03, 2019 at 10:28:12AM +0200, Jean-Jacques Hiblot wrote: > From: Tomi Valkeinen >=20 > This patch adds a led-backlight driver (led_bl), which is similar to > pwm_bl except the driver uses a LED class driver to adjust the > brightness in the HW. Multiple LEDs can be used for a single backlight. >=20 > Signed-off-by: Tomi Valkeinen > Signed-off-by: Jean-Jacques Hiblot > Acked-by: Pavel Machek > Reviewed-by: Daniel Thompson > --- Reviewed-by: Sebastian Reichel (with some suggestions below) > drivers/video/backlight/Kconfig | 7 + > drivers/video/backlight/Makefile | 1 + > drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++ > 3 files changed, 268 insertions(+) > create mode 100644 drivers/video/backlight/led_bl.c >=20 > diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kc= onfig > index 8b081d61773e..585a1787618c 100644 > --- a/drivers/video/backlight/Kconfig > +++ b/drivers/video/backlight/Kconfig > @@ -458,6 +458,13 @@ config BACKLIGHT_RAVE_SP > help > Support for backlight control on RAVE SP device. > =20 > +config BACKLIGHT_LED > + tristate "Generic LED based Backlight Driver" > + depends on LEDS_CLASS && OF > + help > + If you have a LCD backlight adjustable by LED class driver, say Y > + to enable this driver. > + > endif # BACKLIGHT_CLASS_DEVICE > =20 > endmenu > diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/M= akefile > index 63c507c07437..2a67642966a5 100644 > --- a/drivers/video/backlight/Makefile > +++ b/drivers/video/backlight/Makefile > @@ -57,3 +57,4 @@ obj-$(CONFIG_BACKLIGHT_TPS65217) +=3D tps65217_bl.o > obj-$(CONFIG_BACKLIGHT_WM831X) +=3D wm831x_bl.o > obj-$(CONFIG_BACKLIGHT_ARCXCNN) +=3D arcxcnn_bl.o > obj-$(CONFIG_BACKLIGHT_RAVE_SP) +=3D rave-sp-backlight.o > +obj-$(CONFIG_BACKLIGHT_LED) +=3D led_bl.o > diff --git a/drivers/video/backlight/led_bl.c b/drivers/video/backlight/l= ed_bl.c > new file mode 100644 > index 000000000000..3f66549997c8 > --- /dev/null > +++ b/drivers/video/backlight/led_bl.c > @@ -0,0 +1,260 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) 2015-2019 Texas Instruments Incorporated - http://www.= ti.com/ > + * Author: Tomi Valkeinen > + * > + * Based on pwm_bl.c > + */ > + > +#include > +#include > +#include > +#include > + > +struct led_bl_data { > + struct device *dev; > + struct backlight_device *bl_dev; > + struct led_classdev **leds; > + bool enabled; > + int nb_leds; > + unsigned int *levels; > + unsigned int default_brightness; > + unsigned int max_brightness; > +}; > + > +static void led_bl_set_brightness(struct led_bl_data *priv, int level) > +{ > + int i; > + int bkl_brightness; > + > + if (priv->levels) > + bkl_brightness =3D priv->levels[level]; > + else > + bkl_brightness =3D level; > + > + for (i =3D 0; i < priv->nb_leds; i++) > + led_set_brightness(priv->leds[i], bkl_brightness); > + > + priv->enabled =3D true; > +} > + > +static void led_bl_power_off(struct led_bl_data *priv) > +{ > + int i; > + > + if (!priv->enabled) > + return; > + > + for (i =3D 0; i < priv->nb_leds; i++) > + led_set_brightness(priv->leds[i], LED_OFF); > + > + priv->enabled =3D false; > +} > + > +static int led_bl_update_status(struct backlight_device *bl) > +{ > + struct led_bl_data *priv =3D bl_get_data(bl); > + int brightness =3D bl->props.brightness; > + > + if (bl->props.power !=3D FB_BLANK_UNBLANK || > + bl->props.fb_blank !=3D FB_BLANK_UNBLANK || > + bl->props.state & BL_CORE_FBBLANK) > + brightness =3D 0; > + > + if (brightness > 0) > + led_bl_set_brightness(priv, brightness); > + else > + led_bl_power_off(priv); > + > + return 0; > +} > + > +static const struct backlight_ops led_bl_ops =3D { > + .update_status =3D led_bl_update_status, > +}; > + > +static int led_bl_get_leds(struct device *dev, > + struct led_bl_data *priv) > +{ > + int i, nb_leds, ret; > + struct device_node *node =3D dev->of_node; > + struct led_classdev **leds; > + unsigned int max_brightness; > + unsigned int default_brightness; > + > + ret =3D of_count_phandle_with_args(node, "leds", NULL); > + if (ret < 0) { > + dev_err(dev, "Unable to get led count\n"); > + return -EINVAL; > + } > + > + nb_leds =3D ret; > + if (nb_leds < 1) { > + dev_err(dev, "At least one LED must be specified!\n"); > + return -EINVAL; > + } > + > + leds =3D devm_kzalloc(dev, sizeof(struct led_classdev *) * nb_leds, > + GFP_KERNEL); > + if (!leds) > + return -ENOMEM; > + > + for (i =3D 0; i < nb_leds; i++) { > + leds[i] =3D devm_of_led_get(dev, i); > + if (IS_ERR(leds[i])) > + return PTR_ERR(leds[i]); > + } > + > + /* check that the LEDs all have the same brightness range */ > + max_brightness =3D leds[0]->max_brightness; > + for (i =3D 1; i < nb_leds; i++) { > + if (max_brightness !=3D leds[i]->max_brightness) { > + dev_err(dev, "LEDs must have identical ranges\n"); > + return -EINVAL; > + } > + } > + > + /* get the default brightness from the first LED from the list */ > + default_brightness =3D leds[0]->brightness; > + > + priv->nb_leds =3D nb_leds; > + priv->leds =3D leds; > + priv->max_brightness =3D max_brightness; > + priv->default_brightness =3D default_brightness; > + > + return 0; > +} > + > +static int led_bl_parse_levels(struct device *dev, > + struct led_bl_data *priv) > +{ > + struct device_node *node =3D dev->of_node; > + int num_levels; > + u32 value; > + int ret; > + > + if (!node) > + return -ENODEV; > + > + num_levels =3D of_property_count_u32_elems(node, "brightness-levels"); > + if (num_levels > 1) { > + int i; > + unsigned int db; > + u32 *levels =3D NULL; > + > + levels =3D devm_kzalloc(dev, sizeof(u32) * num_levels, > + GFP_KERNEL); > + if (!levels) > + return -ENOMEM; > + > + ret =3D of_property_read_u32_array(node, "brightness-levels", > + levels, > + num_levels); > + if (ret < 0) > + return ret; > + > + /* > + * Try to map actual LED brightness to backlight brightness > + * level > + */ > + db =3D priv->default_brightness; > + for (i =3D 0 ; i < num_levels; i++) { > + if ((i && db > levels[i-1]) && db <=3D levels[i]) > + break; > + } > + priv->default_brightness =3D i; > + priv->max_brightness =3D num_levels - 1; > + priv->levels =3D levels; > + } else if (num_levels >=3D 0) > + dev_warn(dev, "Not enough levels defined\n"); > + > + ret =3D of_property_read_u32(node, "default-brightness-level", &value); > + if (!ret && value <=3D priv->max_brightness) > + priv->default_brightness =3D value; > + else if (!ret && value > priv->max_brightness) > + dev_warn(dev, "Invalid default brightness. Ignoring it\n"); > + > + return 0; > +} > + > +static int led_bl_probe(struct platform_device *pdev) > +{ > + struct backlight_properties props; > + struct led_bl_data *priv; > + int ret, i; > + > + priv =3D devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + platform_set_drvdata(pdev, priv); > + > + priv->dev =3D &pdev->dev; > + > + ret =3D led_bl_get_leds(&pdev->dev, priv); > + if (ret) > + return ret; > + > + ret =3D led_bl_parse_levels(&pdev->dev, priv); > + if (ret < 0) { > + dev_err(&pdev->dev, "Failed to parse DT data\n"); > + return ret; > + } > + > + memset(&props, 0, sizeof(struct backlight_properties)); > + props.type =3D BACKLIGHT_RAW; > + props.max_brightness =3D priv->max_brightness; > + props.brightness =3D priv->default_brightness; > + props.power =3D (priv->default_brightness > 0) ? FB_BLANK_POWERDOWN : > + FB_BLANK_UNBLANK; > + priv->bl_dev =3D backlight_device_register(dev_name(&pdev->dev), > + &pdev->dev, priv, &led_bl_ops, &props); > + if (IS_ERR(priv->bl_dev)) { > + dev_err(&pdev->dev, "Failed to register backlight\n"); > + return PTR_ERR(priv->bl_dev); > + } > + > + for (i =3D 0; i < priv->nb_leds; i++) > + led_sysfs_disable(priv->leds[i]); I suggest to restructure: 1. call led_sysfs_disable 2. use devm_add_action_or_reset() to register the led_sysfs_enable loop 3. use devm_backlight_device_register() to register BL 4. drop the remove function > + > + backlight_update_status(priv->bl_dev); > + > + return 0; > +} > + > +static int led_bl_remove(struct platform_device *pdev) > +{ > + struct led_bl_data *priv =3D platform_get_drvdata(pdev); > + struct backlight_device *bl =3D priv->bl_dev; > + int i; > + > + backlight_device_unregister(bl); > + > + led_bl_power_off(priv); > + for (i =3D 0; i < priv->nb_leds; i++) > + led_sysfs_enable(priv->leds[i]); > + > + return 0; > +} > + > +static const struct of_device_id led_bl_of_match[] =3D { > + { .compatible =3D "led-backlight" }, > + { } > +}; > + > +MODULE_DEVICE_TABLE(of, led_bl_of_match); > + > +static struct platform_driver led_bl_driver =3D { > + .driver =3D { > + .name =3D "led-backlight", > + .of_match_table =3D of_match_ptr(led_bl_of_match), You should drop of_match_ptr(). Since the driver depends on OF, it will always simply return led_bl_of_match. (Also after removing the OF dependency from the driver it would either require led_bl_of_match to be marked __maybe_unused or moving it into a #if CONFIG_OF area to avoid warnings.) -- Sebastian > + }, > + .probe =3D led_bl_probe, > + .remove =3D led_bl_remove, > +}; > + > +module_platform_driver(led_bl_driver); > + > +MODULE_DESCRIPTION("LED based Backlight Driver"); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS("platform:led-backlight"); > --=20 > 2.17.1 >=20 > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel --3lt566epwms7icad Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE72YNB0Y/i3JqeVQT2O7X88g7+poFAl2V39EACgkQ2O7X88g7 +pqCeBAAjejzox0B9olFgbjOZnJehF9gXVkcLB4FgAZ7Jr/RpmJvXeSCBgDWLPT1 swGlEG1dCHiYnY7W8LI/g7vsrLLv2XmkbPX4AQ16fBHYy3udf3AU5v6uswD8W8Qg Cs0n7jS3ojWSjvj5SBFI1Ckfhl8s5h9tVSBZjFMfC5vQ7AUyi+4R4jY+/y+y30WU ZgcjmBX41Rp4XASAIMv1ZMAt0uzynyMQmU23FJ1L9aMIaQgVCYd+z8ynnnTvdWBa hFUE3mbrQLBG3DMrTMclzWRPQJpGnT3sFGW9iFatyseh31j+/zT0AXuZ7SocVWmw 7tXpUs7IxMoNrsl6tB8ThqL+8SIH0eKiJR6aP57qT/WYiTVoJ+WRlZ7Pp+6aT6F7 Uut2u37WYkrttmpKFF/QzquiuO+5KoMT6w5FiieuEHe1yc1GRJS8dJ/uMB87pdnQ ZsKL9sF7LD989nphmvJjqvqBlQhQYDr10oVrCVwuV8t73p3Jljtftx8vSnWGKBbu YtDm+QM/FsWrbXvzgx9Ecy+/SiPgWQ+WPYGu5zvZkzDBmur481POvWGf+F23T4mZ MqKOvJSIyG9nU/+mzavxlAjwWZspWdODltI/ciLdGSYcDrPrQbJKdNEiT/zSZxKb 5Fcpz7U/oQFIUMDULp6TcUT5mU8pMzN2bJeg9wUr/q9ID97rGFU= =znKz -----END PGP SIGNATURE----- --3lt566epwms7icad--