From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [80.241.56.151]) (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 4870C213E85; Fri, 8 Aug 2025 21:32:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.151 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754688763; cv=none; b=pPkH83AbQ0OP5OUUBR8puLSB3X1xvRdGuoLwhp9IaBRMHqCAt8ZipkAamEaWWAq0+/uF9LzTS8+hwJUOWrejzL68uHG8Eplpx6VcV8rM7vSg+Qc6uV567XW+xgqR/rbOZr9Netc5SK378KSqxPnlJuQb/dHxulJL1EYTEXEvsyI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754688763; c=relaxed/simple; bh=AA+L4VD9pvKljjMpU0c3SBNyWo90yERF+Mm3PryYPuk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pDRRZReJffpOeCllKhMJqUTx5Uv8g1ZKuh6gDnubLSbzf8N3+5bctx6qy5Gk0oR3l+YOaUMNX1cVrYFXxJPETGWrS0qZglE7kijcOH3rYa9He/RvfchtJLLZKlU2Lo6n7sTTmR/kazRZvtDLNKaR4kwPVs5O0CFrry2DJnlZGCo= 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=80.241.56.151 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 [IPv6:2001:67c:2050:b231:465::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-101.mailbox.org (Postfix) with ESMTPS id 4bzHLY4jQYz9tDq; Fri, 8 Aug 2025 23:32:37 +0200 (CEST) Authentication-Results: outgoing_mbo_mout; dkim=none; spf=pass (outgoing_mbo_mout: domain of linux@timmermann.space designates 2001:67c:2050:b231:465::102 as permitted sender) smtp.mailfrom=linux@timmermann.space 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 v8 2/2] leds: as3668: Driver for the ams Osram 4-channel i2c LED driver Date: Fri, 8 Aug 2025 23:31:43 +0200 Message-ID: <20250808213143.146732-3-linux@timmermann.space> In-Reply-To: <20250808213143.146732-1-linux@timmermann.space> References: <20250808213143.146732-1-linux@timmermann.space> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4bzHLY4jQYz9tDq 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 | 202 +++++++++++++++++++++++++++++++++++++ 4 files changed, 217 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..8cfb423ddf82 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_AS3668 + tristate "LED support for AMS AS3668" + depends on LEDS_CLASS + depends on I2C + help + This option enables support for the 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..0cfd3b68f90c --- /dev/null +++ b/drivers/leds/leds-as3668.c @@ -0,0 +1,202 @@ +// 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 +#define AS3668_EXPECTED_I2C_ADDR 0x42 + +/* Chip Ident */ + +#define AS3668_CHIP_ID1_REG 0x3e +#define AS3668_CHIP_ID2_REG 0x3f +#define AS3668_CHIP_ID1_EXPECTED_IDENTIFIER 0xa5 +#define AS3668_CHIP_ID2_SERIAL_MASK GENMASK(7, 4) +#define AS3668_CHIP_ID2_REV_MASK GENMASK(3, 0) + +/* Current Control */ + +#define AS3668_CURRX_CONTROL_REG 0x01 +#define AS3668_CURR1_REG 0x02 +#define AS3668_CURR2_REG 0x03 +#define AS3668_CURR3_REG 0x04 +#define AS3668_CURR4_REG 0x05 +#define AS3668_CURRX_MODE_ON 0x1 +#define AS3668_CURRX_CURR1_MASK GENMASK(1, 0) +#define AS3668_CURRX_CURR2_MASK GENMASK(3, 2) +#define AS3668_CURRX_CURR3_MASK GENMASK(5, 4) +#define AS3668_CURRX_CURR4_MASK GENMASK(7, 6) + +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 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 = i2c_smbus_write_byte_data(led->chip->client, + AS3668_CURR1_REG + led->led_id, + brightness); + + if (err) + dev_err(&led->chip->client->dev, "error writing to reg 0x%02x, returned %d\n", + AS3668_CURR1_REG + led->led_id, 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, "'reg' property missing from %s\n", + child->name); + + if (reg < 0 || reg > AS3668_MAX_LEDS) + return dev_err_probe(dev, -EOPNOTSUPP, + "'reg' property in %s is out of scope: %d\n", + child->name, 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_ident, chip_subident, chip_serial, chip_rev; + + /* Check for sensible i2c address */ + if (client->addr != AS3668_EXPECTED_I2C_ADDR) + return dev_err_probe(&client->dev, -EFAULT, + "expected i2c address 0x%02x, got 0x%02x\n", + AS3668_EXPECTED_I2C_ADDR, client->addr); + + /* Read identifier from chip */ + chip_ident = i2c_smbus_read_byte_data(client, AS3668_CHIP_ID1_REG); + + if (chip_ident != AS3668_CHIP_ID1_EXPECTED_IDENTIFIER) + return dev_err_probe(&client->dev, -ENODEV, + "expected chip identifier 0x%02x, got 0x%02x\n", + AS3668_CHIP_ID1_EXPECTED_IDENTIFIER, chip_ident); + + chip_subident = i2c_smbus_read_byte_data(client, AS3668_CHIP_ID2_REG); + chip_serial = FIELD_GET(AS3668_CHIP_ID2_SERIAL_MASK, chip_subident); + chip_rev = FIELD_GET(AS3668_CHIP_ID2_REV_MASK, chip_subident); + + /* Print out information about the chip */ + dev_dbg(&client->dev, + "chip_ident: 0x%02x | chip_subident: 0x%02x | chip_serial: 0x%02x | chip_rev: 0x%02x\n", + chip_ident, chip_subident, chip_serial, chip_rev); + + 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 'on' */ + err = i2c_smbus_write_byte_data(client, AS3668_CURRX_CONTROL_REG, + FIELD_PREP(AS3668_CURRX_CURR1_MASK, AS3668_CURRX_MODE_ON) | + FIELD_PREP(AS3668_CURRX_CURR2_MASK, AS3668_CURRX_MODE_ON) | + FIELD_PREP(AS3668_CURRX_CURR3_MASK, AS3668_CURRX_MODE_ON) | + FIELD_PREP(AS3668_CURRX_CURR4_MASK, AS3668_CURRX_MODE_ON)); + + /* 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, "error during hardware initialization\n"); + + return 0; +} + +static void as3668_remove(struct i2c_client *client) +{ + int err = i2c_smbus_write_byte_data(client, AS3668_CURRX_CONTROL_REG, 0); + + if (err) + dev_err(&client->dev, "couldn't deinit device\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"); -- 2.50.1