From patchwork Wed Jun 11 08:31:51 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Timmermann X-Patchwork-Id: 895795 Received: from mout-p-202.mailbox.org (mout-p-202.mailbox.org [80.241.56.172]) (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 AD143238C0C; Wed, 11 Jun 2025 08:32:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749630740; cv=none; b=OzoOcHw9aFy9jbBB9W7/Fyv4qV4Yl6hFx1+CZ0yQLQlSIV5gWdYQe260m3Ei1Nfe80gTG78wyz2lsCauBgClo01EqRHC5Dez4CAFu0H4lt0UcRd3vzSTZ/yCWbvme6Xg/oPL9s46aP+yUHyVCcZxxCKBacjqqJ2rKv+3f2Vz7PI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749630740; c=relaxed/simple; bh=trUX0gVPJ0n0sTl+vIBz2GzynZMnGSykW9Y1wQxpzI0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ioU8sSjiZnN9xwC9VBz1QWxoXpVQQr/bhghWN26DZE2O0f6orxdojvB7hp+BBUxAakthXsFY99bDvObgzn9ikzv2ZOpJyPk8X5I1wPN+Tl8eXBJ1hHArmrmk133cQ/HmFc4mLC6lq7Pup4WDYI1TXVItCXJRMOOsZxcHIx0+QJY= 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=80.241.56.172 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 smtp202.mailbox.org (smtp202.mailbox.org [IPv6:2001:67c:2050:b231:465::202]) (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-202.mailbox.org (Postfix) with ESMTPS id 4bHJmk6GXzz9snl; Wed, 11 Jun 2025 10:32:06 +0200 (CEST) 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 v6 2/2] leds: as3668: Driver for the ams Osram 4-channel i2c LED driver Date: Wed, 11 Jun 2025 10:31:51 +0200 Message-ID: <20250611083151.22150-3-linux@timmermann.space> In-Reply-To: <20250611083151.22150-1-linux@timmermann.space> References: <20250611083151.22150-1-linux@timmermann.space> Precedence: bulk X-Mailing-List: linux-leds@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Queue-Id: 4bHJmk6GXzz9snl 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 | 204 +++++++++++++++++++++++++++++++++++++ 4 files changed, 219 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..cb1b90217ca6 --- /dev/null +++ b/drivers/leds/leds-as3668.c @@ -0,0 +1,204 @@ +// 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 Registers */ +#define AS3668_CHIP_ID1 0x3e +#define AS3668_CHIP_ID2 0x3f + +#define AS3668_CHIP_ID2_SERIAL_MASK GENMASK(7, 4) +#define AS3668_CHIP_ID2_REV_MASK GENMASK(3, 0) + +#define AS3668_CURRX_CONTROL 0x01 +#define AS3668_CURR1 0x02 +#define AS3668_CURR2 0x03 +#define AS3668_CURR3 0x04 +#define AS3668_CURR4 0x05 + +/* Constants */ +#define AS3668_CHIP_IDENT 0xa5 +#define AS3668_CHIP_REV1 0x01 + +struct as3668_led { + struct led_classdev cdev; + struct as3668 *chip; + struct fwnode_handle *fwnode; + + int num; +}; + +struct as3668 { + struct i2c_client *client; + struct as3668_led leds[AS3668_MAX_LEDS]; +}; + +static int as3668_read_value(struct i2c_client *client, u8 reg) +{ + return i2c_smbus_read_byte_data(client, reg); +} + +static int as3668_write_value(struct i2c_client *client, u8 reg, u8 value) +{ + int err = i2c_smbus_write_byte_data(client, reg, value); + + if (err) + dev_err(&client->dev, "error writing to reg 0x%02x, returned %d\n", reg, err); + + return err; +} + +static enum led_brightness as3668_brightness_get(struct led_classdev *cdev) +{ + struct as3668_led *led = container_of(cdev, struct as3668_led, cdev); + + return as3668_read_value(led->chip->client, AS3668_CURR1 + led->num); +} + +static void as3668_brightness_set(struct led_classdev *cdev, enum led_brightness brightness) +{ + struct as3668_led *led = container_of(cdev, struct as3668_led, cdev); + + as3668_write_value(led->chip->client, AS3668_CURR1 + led->num, brightness); +} + +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) { + dev_err(dev, "unable to read device tree led reg, err %d\n", err); + return err; + } + + if (reg < 0 || reg > AS3668_MAX_LEDS) { + dev_err(dev, "unsupported led reg %d\n", reg); + return -EOPNOTSUPP; + } + + led = &as3668->leds[reg]; + led->fwnode = of_fwnode_handle(child); + + led->num = 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) { + dev_err(dev, "failed to register %d LED\n", reg); + return err; + } + } + + return 0; +} + +static int as3668_probe(struct i2c_client *client) +{ + u8 chip_id1, chip_id2, chip_serial, chip_rev; + struct as3668 *as3668; + + /* Check for sensible i2c address */ + if (client->addr != 0x42) + return dev_err_probe(&client->dev, -EFAULT, + "unexpected address for as3668 device\n"); + + /* Read identifier from chip */ + chip_id1 = as3668_read_value(client, AS3668_CHIP_ID1); + + if (chip_id1 != AS3668_CHIP_IDENT) + return dev_err_probe(&client->dev, -ENODEV, + "chip reported wrong id: 0x%02x\n", chip_id1); + + /* Check the revision */ + chip_id2 = as3668_read_value(client, AS3668_CHIP_ID2); + chip_serial = FIELD_GET(AS3668_CHIP_ID2_SERIAL_MASK, chip_id2); + chip_rev = FIELD_GET(AS3668_CHIP_ID2_REV_MASK, chip_id2); + + if (chip_rev != AS3668_CHIP_REV1) + dev_warn(&client->dev, "unexpected chip revision\n"); + + /* Print out information about the chip */ + dev_dbg(&client->dev, + "chip_id: 0x%02x | chip_id2: 0x%02x | chip_serial: 0x%02x | chip_rev: 0x%02x\n", + chip_id1, chip_id2, chip_serial, chip_rev); + + as3668 = devm_kzalloc(&client->dev, sizeof(*as3668), GFP_KERNEL); + + if (!as3668) + return -ENOMEM; + + as3668->client = client; + int err = as3668_dt_init(as3668); + + if (err) { + dev_err(&client->dev, "failed to initialize device, err %d\n", err); + return err; + } + + /* Initialize the chip */ + as3668_write_value(client, AS3668_CURRX_CONTROL, 0x55); + as3668_write_value(client, AS3668_CURR1, 0x00); + as3668_write_value(client, AS3668_CURR2, 0x00); + as3668_write_value(client, AS3668_CURR3, 0x00); + as3668_write_value(client, AS3668_CURR4, 0x00); + + return 0; +} + +static void as3668_remove(struct i2c_client *client) +{ + as3668_write_value(client, AS3668_CURRX_CONTROL, 0x0); +} + +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");