From patchwork Thu Jan 18 17:32:39 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Duje_Mihanovi=C4=87?= X-Patchwork-Id: 763727 Received: from mx.skole.hr (mx2.hosting.skole.hr [161.53.165.186]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D81C92D78F; Thu, 18 Jan 2024 17:33:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=161.53.165.186 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705599215; cv=none; b=aJLySe7YuM71/PIoCbTwx7zYWu763tJVSsay/Okhtha6jO/B1Ri1MPnbckkCaisrwyDP7myd0KTH6VZv0zPMDYAYXlwHcthV5QolWYNMqYhlxfDAu6y2no6EfBbWhf/Pu9QJFrBPYYme+YhxaVQAgcyTe5ThpNseJU2+wgz5UYg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705599215; c=relaxed/simple; bh=RL8pDKSS8GEXEpA6kwbUcC+c8mq/JIBYJcEdllWUPgM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=CixFsQcaqy7wn95JEFJS8O6Tue/709qbwUXKm+iRSv7SxIp4qpnfw1RXivkIUWlQHjZbsQ7m1mhyHMFTTjmC8TDQi0H1ZyfpSs53WnDkLAWkmHCzjATnWLA3tIxwY+cFQ20nYw77s1HV6OEzZ5yG8R4ANCco4OOImHfu/Tlt1xE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=skole.hr; spf=pass smtp.mailfrom=skole.hr; arc=none smtp.client-ip=161.53.165.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=skole.hr Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=skole.hr Received: from mx2.hosting.skole.hr (localhost.localdomain [127.0.0.1]) by mx.skole.hr (mx.skole.hr) with ESMTP id 8287F83381; Thu, 18 Jan 2024 18:33:25 +0100 (CET) From: =?utf-8?q?Duje_Mihanovi=C4=87?= Date: Thu, 18 Jan 2024 18:32:39 +0100 Subject: [PATCH v2 2/2] backlight: Add Kinetic KTD2801 driver Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240118-ktd2801-v2-2-425cf32e0769@skole.hr> References: <20240118-ktd2801-v2-0-425cf32e0769@skole.hr> In-Reply-To: <20240118-ktd2801-v2-0-425cf32e0769@skole.hr> To: Lee Jones , Daniel Thompson , Jingoo Han , Pavel Machek , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Helge Deller Cc: Karel Balej , ~postmarketos/upstreaming@lists.sr.ht, dri-devel@lists.freedesktop.org, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org, =?utf-8?q?Duje_Mihanovi=C4=87?= X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=openpgp-sha256; l=7328; i=duje.mihanovic@skole.hr; h=from:subject:message-id; bh=RL8pDKSS8GEXEpA6kwbUcC+c8mq/JIBYJcEdllWUPgM=; b=owEBbQKS/ZANAwAIAZoRnrBCLZbhAcsmYgBlqWDB5L3h2dG7RFFheDJevRR/i3WGXidWHtR/D aLaWTJYRdSJAjMEAAEIAB0WIQRT351NnD/hEPs2LXiaEZ6wQi2W4QUCZalgwQAKCRCaEZ6wQi2W 4UYID/9rv5+qAkM5dST6CQP69Me/+I0XI0eBe/GLSMEn8iI/9LruOL6+Yf/8nR3NbKXF1PHhmkt WtnQVZvVgfZqPG0bzY1okOK1GG9jSFiw0rfMHMz1sSKfTeu7y8iJN2N6IVye7XJ2WsLqDc2O8ch pOMw1C6m93ePflYp0JP/Lv0P9oVuAb0OuLDT1z7Ui+j6+eV34rfB/BSKTCTKF9dL/8GT9wm6Dpf BsshDeZ29VDbrhaOijY5XvhL89s/Wnzgg26W/WrLryxVgBnGHtUnqjac2wqC3NiXpmE9WYW+aDW EacCbJ5TTB9eEwkbRU/iJQ9RM/ZU/RKt5hVJfQPKmCDj/aCl68VT7qf+LJU38WytmSiA5J8hrFe fvSowFIw0hfwg+kv9XX2saE9vlcVn4tfoOBc3Vl4zLlGlKKmIlsfHgG5IUVzypQW+j9ImC+AN01 dD4TB4fFo36TIo53HspodHQ4cT0c+iLFciMAOTTYSckv8ouVSOTybdWqYv0ATYKQsOLn1KfXO9Z cGhOWQvZChHFw+GIgrGR8DPdEDkGGLau4+qBb14qoukW9WfZXzWd5LO/lcTCvA5WC09wrFdVrRV LGWFDrjG0WMYinlmvENyu+ikech6ddHE5kOEfgbaSNDJCQZwCgvyen4eBkENf2ujs25o45LJASI mMSwXabVgpizOJQ== X-Developer-Key: i=duje.mihanovic@skole.hr; a=openpgp; fpr=53DF9D4D9C3FE110FB362D789A119EB0422D96E1 Add driver for the Kinetic KTD2801 backlight driver. Signed-off-by: Duje Mihanović --- Shared ExpressWire handling code and preemption watchdogs haven't been implemented in this version as my questions regarding these two weren't answered. --- MAINTAINERS | 6 ++ drivers/video/backlight/Kconfig | 7 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/ktd2801-backlight.c | 149 ++++++++++++++++++++++++++++ 4 files changed, 163 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index a7c4cf8201e0..1e25d760f312 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11884,6 +11884,12 @@ S: Maintained F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktd253.yaml F: drivers/video/backlight/ktd253-backlight.c +KTD2801 BACKLIGHT DRIVER +M: Duje Mihanović +S: Maintained +F: Documentation/devicetree/bindings/leds/backlight/kinetic,ktd2801.yaml +F: drivers/video/backlight/ktd2801-backlight.c + KTEST M: Steven Rostedt M: John Hawley diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 51387b1ef012..a2b268293345 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -183,6 +183,13 @@ config BACKLIGHT_KTD253 which is a 1-wire GPIO-controlled backlight found in some mobile phones. +config BACKLIGHT_KTD2801 + tristate "Backlight Driver for Kinetic KTD2801" + depends on GPIOLIB || COMPILE_TEST + help + Say Y to enable the backlight driver for the Kinetic KTD2801 1-wire + GPIO-controlled backlight found in Samsung Galaxy Core Prime VE LTE. + config BACKLIGHT_KTZ8866 tristate "Backlight Driver for Kinetic KTZ8866" depends on I2C diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index f72e1c3c59e9..b33b647f31ca 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -35,6 +35,7 @@ obj-$(CONFIG_BACKLIGHT_HP680) += hp680_bl.o obj-$(CONFIG_BACKLIGHT_HP700) += jornada720_bl.o obj-$(CONFIG_BACKLIGHT_IPAQ_MICRO) += ipaq_micro_bl.o obj-$(CONFIG_BACKLIGHT_KTD253) += ktd253-backlight.o +obj-$(CONFIG_BACKLIGHT_KTD2801) += ktd2801-backlight.o obj-$(CONFIG_BACKLIGHT_KTZ8866) += ktz8866.o obj-$(CONFIG_BACKLIGHT_LM3533) += lm3533_bl.o obj-$(CONFIG_BACKLIGHT_LM3630A) += lm3630a_bl.o diff --git a/drivers/video/backlight/ktd2801-backlight.c b/drivers/video/backlight/ktd2801-backlight.c new file mode 100644 index 000000000000..bbcb2e2059a2 --- /dev/null +++ b/drivers/video/backlight/ktd2801-backlight.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include +#include + +/* These values have been extracted from Samsung's driver. */ +#define KTD2801_EXPRESSWIRE_DETECT_DELAY_US 150 +#define KTD2801_EXPRESSWIRE_DETECT_US 270 +#define KTD2801_LOW_BIT_HIGH_TIME_US 5 +#define KTD2801_LOW_BIT_LOW_TIME_US (4 * KTD2801_HIGH_BIT_LOW_TIME_US) +#define KTD2801_HIGH_BIT_LOW_TIME_US 5 +#define KTD2801_HIGH_BIT_HIGH_TIME_US (4 * KTD2801_HIGH_BIT_LOW_TIME_US) +#define KTD2801_DATA_START_US 5 +#define KTD2801_END_OF_DATA_LOW_US 10 +#define KTD2801_END_OF_DATA_HIGH_US 350 +#define KTD2801_PWR_DOWN_DELAY_US 2600 + +#define KTD2801_DEFAULT_BRIGHTNESS 100 +#define KTD2801_MAX_BRIGHTNESS 255 + +struct ktd2801_backlight { + struct backlight_device *bd; + struct gpio_desc *gpiod; + bool was_on; +}; + +static int ktd2801_update_status(struct backlight_device *bd) +{ + struct ktd2801_backlight *ktd2801 = bl_get_data(bd); + u8 brightness = (u8) backlight_get_brightness(bd); + + if (backlight_is_blank(bd)) { + gpiod_set_value(ktd2801->gpiod, 0); + udelay(KTD2801_PWR_DOWN_DELAY_US); + ktd2801->was_on = false; + return 0; + } + + if (!ktd2801->was_on) { + gpiod_set_value(ktd2801->gpiod, 1); + udelay(KTD2801_EXPRESSWIRE_DETECT_DELAY_US); + gpiod_set_value(ktd2801->gpiod, 0); + udelay(KTD2801_EXPRESSWIRE_DETECT_US); + gpiod_set_value(ktd2801->gpiod, 1); + ktd2801->was_on = true; + } + + gpiod_set_value(ktd2801->gpiod, 1); + udelay(KTD2801_DATA_START_US); + + for (int i = 0; i < 8; i++) { + u8 next_bit = (brightness & 0x80) >> 7; + + if (!next_bit) { + gpiod_set_value(ktd2801->gpiod, 0); + udelay(KTD2801_LOW_BIT_LOW_TIME_US); + gpiod_set_value(ktd2801->gpiod, 1); + udelay(KTD2801_LOW_BIT_HIGH_TIME_US); + } else { + gpiod_set_value(ktd2801->gpiod, 0); + udelay(KTD2801_HIGH_BIT_LOW_TIME_US); + gpiod_set_value(ktd2801->gpiod, 1); + udelay(KTD2801_HIGH_BIT_HIGH_TIME_US); + } + brightness <<= 1; + } + gpiod_set_value(ktd2801->gpiod, 0); + udelay(KTD2801_END_OF_DATA_LOW_US); + gpiod_set_value(ktd2801->gpiod, 1); + udelay(KTD2801_END_OF_DATA_HIGH_US); + return 0; +} + +static const struct backlight_ops ktd2801_backlight_ops = { + .update_status = ktd2801_update_status, +}; + +static int ktd2801_backlight_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct backlight_device *bd; + struct ktd2801_backlight *ktd2801; + u32 brightness, max_brightness; + int ret; + + ktd2801 = devm_kzalloc(dev, sizeof(*ktd2801), GFP_KERNEL); + if (!ktd2801) + return -ENOMEM; + ktd2801->was_on = true; + + ret = device_property_read_u32(dev, "max-brightness", &max_brightness); + if (ret) + max_brightness = KTD2801_MAX_BRIGHTNESS; + if (max_brightness > KTD2801_MAX_BRIGHTNESS) { + dev_err(dev, "illegal max brightness specified\n"); + max_brightness = KTD2801_MAX_BRIGHTNESS; + } + + ret = device_property_read_u32(dev, "default-brightness", &brightness); + if (ret) + brightness = KTD2801_DEFAULT_BRIGHTNESS; + if (brightness > max_brightness) { + dev_err(dev, "default brightness exceeds max\n"); + brightness = max_brightness; + } + + ktd2801->gpiod = devm_gpiod_get(dev, "ctrl", GPIOD_OUT_HIGH); + if (IS_ERR(ktd2801->gpiod)) + return dev_err_probe(dev, PTR_ERR(dev), + "failed to get backlight GPIO"); + gpiod_set_consumer_name(ktd2801->gpiod, dev_name(dev)); + + bd = devm_backlight_device_register(dev, dev_name(dev), dev, ktd2801, + &ktd2801_backlight_ops, NULL); + if (IS_ERR(bd)) + return dev_err_probe(dev, PTR_ERR(bd), + "failed to register backlight"); + + bd->props.max_brightness = max_brightness; + bd->props.brightness = brightness; + + ktd2801->bd = bd; + platform_set_drvdata(pdev, bd); + backlight_update_status(bd); + + return 0; +} + +static const struct of_device_id ktd2801_of_match[] = { + { .compatible = "kinetic,ktd2801" }, + { } +}; +MODULE_DEVICE_TABLE(of, ktd2801_of_match); + +static struct platform_driver ktd2801_backlight_driver = { + .driver = { + .name = "ktd2801-backlight", + .of_match_table = ktd2801_of_match, + }, + .probe = ktd2801_backlight_probe, +}; +module_platform_driver(ktd2801_backlight_driver); + +MODULE_AUTHOR("Duje Mihanović "); +MODULE_DESCRIPTION("Kinetic KTD2801 Backlight Driver"); +MODULE_LICENSE("GPL");