From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-201.mailbox.org (mout-p-201.mailbox.org [80.241.56.171]) (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 A738F1DA0E1; Mon, 17 Nov 2025 02:00:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763344860; cv=none; b=JuLqik7t3EXTa6QQop0z4/jSzj34SRzLxNPJeXIUbnX8RYvFAjXl1tXTUbaY4zVt/TEWmC6tJgnksQsk7iF58yph91TcFurkdBlvySKBV0kXJJLh+19b20jq8H6LpxI6TgI6VxEMW6xUEeaIVnjVE2pCsxQk6ieWLQP/DOn/YMA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763344860; c=relaxed/simple; bh=IWvb0i+ssFD4m+4AsJJdxGAYAExiZjQ5qAN41PUi4B0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=u0B/37rMa09Cp+8ZaKgTICswAXD1qsMOIgQS5Y0ZLCuEJTDblCfNFvoT6FExywhmrNwLTAlBrUJRCoBuI8L9gnU9aGXIq3vFs2ifj/2Z0DNk1kJDv7nwcQEHmPUSN6YD1jbQcMr3Vs3x24yyXs1yuWYhzc2Vp+euBd/WMZv/LI4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=timmermann.space; spf=pass smtp.mailfrom=timmermann.space; arc=none smtp.client-ip=80.241.56.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=timmermann.space Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=timmermann.space Received: from smtp102.mailbox.org (smtp102.mailbox.org [10.196.197.102]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-201.mailbox.org (Postfix) with ESMTPS id 4d8rYq2dNtz9tKq; Mon, 17 Nov 2025 03:00:47 +0100 (CET) From: Lukas Timmermann To: lee@kernel.org, pavel@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org Cc: linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux@timmermann.space Subject: [PATCH v10 2/2] leds: as3668: Driver for the ams Osram 4-channel i2c LED driver Date: Mon, 17 Nov 2025 03:00:08 +0100 Message-ID: <20251117020008.316648-3-linux@timmermann.space> In-Reply-To: <20251117020008.316648-1-linux@timmermann.space> References: <20251117020008.316648-1-linux@timmermann.space> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Since there were no existing drivers for the AS3668 or related devices, a new driver was introduced in a separate file. Similar devices were reviewed, but none shared enough characteristics to justify code reuse. As a result, this driver is written specifically for the AS3668. Signed-off-by: Lukas Timmermann --- MAINTAINERS | 1 + drivers/leds/Kconfig | 13 +++ drivers/leds/Makefile | 1 + drivers/leds/leds-as3668.c | 222 +++++++++++++++++++++++++++++++++++++ 4 files changed, 237 insertions(+) create mode 100644 drivers/leds/leds-as3668.c diff --git a/MAINTAINERS b/MAINTAINERS index 091206c54c63..945d78fef380 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3511,6 +3511,7 @@ M: Lukas Timmermann L: linux-leds@vger.kernel.org S: Maintained F: Documentation/devicetree/bindings/leds/ams,as3668.yaml +F: drivers/leds/leds-as3668.c ASAHI KASEI AK7375 LENS VOICE COIL DRIVER M: Tianshu Qiu diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index a104cbb0a001..ec37d55ac14e 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -100,6 +100,19 @@ config LEDS_ARIEL Say Y to if your machine is a Dell Wyse 3020 thin client. +config LEDS_OSRAM_AMS_AS3668 + tristate "LED support for Osram AMS AS3668" + depends on LEDS_CLASS + depends on I2C + help + This option enables support for the Osram AMS AS3668 LED controller. + The AS3668 provides up to four LED channels and is controlled via + the I2C bus. This driver offers basic brightness control for each + channel, without support for blinking or other advanced features. + + To compile this driver as a module, choose M here: the module + will be called leds-as3668. + config LEDS_AW200XX tristate "LED support for Awinic AW20036/AW20054/AW20072/AW20108" depends on LEDS_CLASS diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index 2f170d69dcbf..983811384fec 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_LEDS_ADP5520) += leds-adp5520.o obj-$(CONFIG_LEDS_AN30259A) += leds-an30259a.o obj-$(CONFIG_LEDS_APU) += leds-apu.o obj-$(CONFIG_LEDS_ARIEL) += leds-ariel.o +obj-$(CONFIG_LEDS_AS3668) += leds-as3668.o obj-$(CONFIG_LEDS_AW200XX) += leds-aw200xx.o obj-$(CONFIG_LEDS_AW2013) += leds-aw2013.o obj-$(CONFIG_LEDS_BCM6328) += leds-bcm6328.o diff --git a/drivers/leds/leds-as3668.c b/drivers/leds/leds-as3668.c new file mode 100644 index 000000000000..8c43429f2856 --- /dev/null +++ b/drivers/leds/leds-as3668.c @@ -0,0 +1,222 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Osram AMS AS3668 LED Driver IC + * + * Copyright (C) 2025 Lukas Timmermann + */ + +#include +#include +#include +#include +#include + +#define AS3668_MAX_LEDS 4 + +/* Chip Ident */ + +#define AS3668_CHIP_ID1_REG 0x3e +#define AS3668_CHIP_ID 0xa5 + +/* Current Control */ + +#define AS3668_CURR_MODE_REG 0x01 +#define AS3668_CURR_MODE_OFF 0x0 +#define AS3668_CURR_MODE_ON 0x1 +#define AS3668_CURR1_MODE_MASK GENMASK(1, 0) +#define AS3668_CURR2_MODE_MASK GENMASK(3, 2) +#define AS3668_CURR3_MODE_MASK GENMASK(5, 4) +#define AS3668_CURR4_MODE_MASK GENMASK(7, 6) +#define AS3668_CURR1_REG 0x02 +#define AS3668_CURR2_REG 0x03 +#define AS3668_CURR3_REG 0x04 +#define AS3668_CURR4_REG 0x05 + +struct as3668_led { + struct led_classdev cdev; + struct as3668 *chip; + struct fwnode_handle *fwnode; + int led_id; +}; + +struct as3668 { + struct i2c_client *client; + struct as3668_led leds[AS3668_MAX_LEDS]; +}; + +static void as3668_channel_mode_set(struct as3668 *as3668, int led_id, u8 mode) +{ + int err; + u8 reg; + + reg = i2c_smbus_read_byte_data(as3668->client, AS3668_CURR_MODE_REG); + if (reg < 0) { + dev_err(&as3668->client->dev, "failed to read channel modes\n"); + return; + } + + switch (led_id) { + case 0: + reg &= ~AS3668_CURR1_MODE_MASK; + reg |= FIELD_PREP(AS3668_CURR1_MODE_MASK, mode); + break; + case 1: + reg &= ~AS3668_CURR2_MODE_MASK; + reg |= FIELD_PREP(AS3668_CURR2_MODE_MASK, mode); + break; + case 2: + reg &= ~AS3668_CURR3_MODE_MASK; + reg |= FIELD_PREP(AS3668_CURR3_MODE_MASK, mode); + break; + case 3: + reg &= ~AS3668_CURR4_MODE_MASK; + reg |= FIELD_PREP(AS3668_CURR4_MODE_MASK, mode); + break; + default: + return; + } + + err = i2c_smbus_write_byte_data(as3668->client, AS3668_CURR_MODE_REG, reg); + if (err) + dev_err(&as3668->client->dev, "failed to set channel modes\n"); +} + +static enum led_brightness as3668_brightness_get(struct led_classdev *cdev) +{ + struct as3668_led *led = container_of(cdev, struct as3668_led, cdev); + + return i2c_smbus_read_byte_data(led->chip->client, AS3668_CURR1_REG + led->led_id); +} + +static void as3668_brightness_set(struct led_classdev *cdev, enum led_brightness brightness) +{ + struct as3668_led *led = container_of(cdev, struct as3668_led, cdev); + int err; + + if (brightness == 0) + as3668_channel_mode_set(led->chip, led->led_id, AS3668_CURR_MODE_OFF); + else + as3668_channel_mode_set(led->chip, led->led_id, AS3668_CURR_MODE_ON); + + err = i2c_smbus_write_byte_data(led->chip->client, + AS3668_CURR1_REG + led->led_id, + brightness); + + if (err) + dev_err(&led->chip->client->dev, "failed to set brightness: %d\n", err); +} + +static int as3668_dt_init(struct as3668 *as3668) +{ + struct device *dev = &as3668->client->dev; + struct as3668_led *led; + struct led_init_data init_data = {}; + int err; + u32 reg; + + for_each_available_child_of_node_scoped(dev_of_node(dev), child) { + err = of_property_read_u32(child, "reg", ®); + if (err) + return dev_err_probe(dev, err, "failed to read 'reg' property"); + + if (reg < 0 || reg > AS3668_MAX_LEDS) + return dev_err_probe(dev, -EOPNOTSUPP, + "unsupported LED: %d\n", reg); + + led = &as3668->leds[reg]; + led->fwnode = of_fwnode_handle(child); + + led->led_id = reg; + led->chip = as3668; + + led->cdev.max_brightness = U8_MAX; + led->cdev.brightness_get = as3668_brightness_get; + led->cdev.brightness_set = as3668_brightness_set; + + init_data.fwnode = led->fwnode; + init_data.default_label = ":"; + + err = devm_led_classdev_register_ext(dev, &led->cdev, &init_data); + if (err) + return dev_err_probe(dev, err, "failed to register LED %d\n", reg); + } + + return 0; +} + +static int as3668_probe(struct i2c_client *client) +{ + struct as3668 *as3668; + int err; + u8 chip_id; + + chip_id = i2c_smbus_read_byte_data(client, AS3668_CHIP_ID1_REG); + if (chip_id != AS3668_CHIP_ID) + return dev_err_probe(&client->dev, -ENODEV, + "expected chip ID 0x%02x, got 0x%02x\n", + AS3668_CHIP_ID, chip_id); + + as3668 = devm_kzalloc(&client->dev, sizeof(*as3668), GFP_KERNEL); + if (!as3668) + return -ENOMEM; + + as3668->client = client; + + err = as3668_dt_init(as3668); + if (err) + return err; + + /* Set all four channel modes to 'off' */ + err = i2c_smbus_write_byte_data(client, AS3668_CURR_MODE_REG, + FIELD_PREP(AS3668_CURR1_MODE_MASK, AS3668_CURR_MODE_OFF) | + FIELD_PREP(AS3668_CURR2_MODE_MASK, AS3668_CURR_MODE_OFF) | + FIELD_PREP(AS3668_CURR3_MODE_MASK, AS3668_CURR_MODE_OFF) | + FIELD_PREP(AS3668_CURR4_MODE_MASK, AS3668_CURR_MODE_OFF)); + + /* Set initial currents to 0mA */ + err |= i2c_smbus_write_byte_data(client, AS3668_CURR1_REG, 0); + err |= i2c_smbus_write_byte_data(client, AS3668_CURR2_REG, 0); + err |= i2c_smbus_write_byte_data(client, AS3668_CURR3_REG, 0); + err |= i2c_smbus_write_byte_data(client, AS3668_CURR4_REG, 0); + + if (err) + return dev_err_probe(&client->dev, -EIO, "failed to write to the device\n"); + + return 0; +} + +static void as3668_remove(struct i2c_client *client) +{ + int err; + + err = i2c_smbus_write_byte_data(client, AS3668_CURR_MODE_REG, 0); + if (err) + dev_err(&client->dev, "failed to turn off the LEDs\n"); +} + +static const struct i2c_device_id as3668_idtable[] = { + { "as3668" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, as3668_idtable); + +static const struct of_device_id as3668_match_table[] = { + { .compatible = "ams,as3668" }, + { } +}; +MODULE_DEVICE_TABLE(of, as3668_match_table); + +static struct i2c_driver as3668_driver = { + .driver = { + .name = "leds_as3668", + .of_match_table = as3668_match_table, + }, + .probe = as3668_probe, + .remove = as3668_remove, + .id_table = as3668_idtable, +}; +module_i2c_driver(as3668_driver); + +MODULE_AUTHOR("Lukas Timmermann "); +MODULE_DESCRIPTION("AS3668 LED driver"); +MODULE_LICENSE("GPL"); -- 2.51.2