* [PATCH v9 0/2] Support for Osram as3668 LED driver @ 2025-10-14 15:26 Lukas Timmermann 2025-10-14 15:26 ` [PATCH v9 1/2] dt-bindings: leds: Add new as3668 support Lukas Timmermann 2025-10-14 15:26 ` [PATCH v9 2/2] leds: as3668: Driver for the ams Osram 4-channel i2c LED driver Lukas Timmermann 0 siblings, 2 replies; 4+ messages in thread From: Lukas Timmermann @ 2025-10-14 15:26 UTC (permalink / raw) To: lee, pavel, robh, krzk+dt, conor+dt Cc: linux-leds, devicetree, linux-kernel, linux This patch adds basic support for the as3668 driver IC via I2C interface. The IC is capable of driving four individual LEDs up to 25.5mA per channel. Hardware blinking would be theoretically possible, but this chip only supports a few set on/off-delays which makes using that feature unfeasable, therefore my driver doesn't offer that capability. It's intended applications is in mobile devices such as phones, tablets and cameras. This driver was tested and is working on a samsung-manta which is running postmarketOS with a near mainline kernel. The register names and values are taken from the official datasheet which can be found here: https://www.mouser.com/datasheet/2/588/AS3668_DS000196_1-00-1512816.pdf Please note: This is my first suggested patch to the kernel. checkpatch.pl runs without warnings or errors. I've read the docs in regards to the led subsystem, coding style and submission of patches, but I'm still a bit unsure about the general workflow. I will try my best. Changes in v9: - Tabbed out values. (@Lee) - Removed newlines. (@Lee) - Renamed chip id constant and variables to be more clear. (@Lee) - Removed unnecessary comments. (@Lee) - Removed unnecessary debug message. (@Lee) - Separate declaration and assignment of err variable. (@Lee) - Link to v8: https://lore.kernel.org/all/20250808213143.146732-1-linux@timmermann.space/ Changes in v8: - Rearranged constants. - Removed more newlines. - Changed error messages to be more clear. - Renamed variables. - Removed revision check. - Removed extra i2c read&write functions. - Made initalisation code more readable with bitmasks. - The code now wraps around before 100 chars instead of 80. - Link to v7: https://lore.kernel.org/all/20250708141114.134950-1-linux@timmermann.space/ Changes in v7: - Simplified multiple error messages. They now use dev_err_probe(). - Removed some newlines. - Link to v6: https://lore.kernel.org/all/20250611083151.22150-1-linux@timmermann.space/ Changes in v6: - Fixed missing error handling during init - Fixed missing newline in error messages - Fixed size calculation for memory allocation - Fixed error handling for memory allocation - Link to v5: https://lore.kernel.org/lkml/20250608231854.75668-1-linux@timmermann.space/ Changes in v5: - Fixed debug and error messages using wrong format specifiers. - Fixed missing include bitwise.h. - Changed commit message for dt file to fit expected style. - Link to v4: https://lore.kernel.org/lkml/20250607215049.29259-1-linux@timmermann.space/ Changes in v4: - Fixed some mistakes made in the dt file pointed out in v3. - Swapped dt and driver in patch series. DT now comes first. - Fixed errors in Kconfig due to last minute changes. - Added dt file into MAINTAINERS file. - Link to v3: https://lore.kernel.org/lkml/20250604225838.102910-2-linux@timmermann.space/ Changes in v3: - Fixed an extra whitespace in the dt bindings documentation. - Sent patch to all related lists and maintainers. - Link to v2: https://lore.kernel.org/lkml/20250531120715.302870-4-linux@timmermann.space/ Changes in v2: - Fixed reading led subnodes in dt incorrectly, which caused wrong numbering and a segfault when removing the driver module - Fixed calling of_property_read_u8 with an int, causing a compiler error - Added more error checking during writes to the i2c bus - Link to v1: https://lore.kernel.org/linux-leds/20250530184219.78085-3-linux@timmermann.space/ Signed-off-by: Lukas Timmermann <linux@timmermann.space> Lukas Timmermann (2): dt-bindings: leds: Add new as3668 support leds: as3668: Driver for the ams Osram 4-channel i2c LED driver .../devicetree/bindings/leds/ams,as3668.yaml | 74 +++++++ MAINTAINERS | 7 + drivers/leds/Kconfig | 13 ++ drivers/leds/Makefile | 1 + drivers/leds/leds-as3668.c | 188 ++++++++++++++++++ 5 files changed, 283 insertions(+) create mode 100644 Documentation/devicetree/bindings/leds/ams,as3668.yaml create mode 100644 drivers/leds/leds-as3668.c -- 2.51.0 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v9 1/2] dt-bindings: leds: Add new as3668 support 2025-10-14 15:26 [PATCH v9 0/2] Support for Osram as3668 LED driver Lukas Timmermann @ 2025-10-14 15:26 ` Lukas Timmermann 2025-10-14 15:26 ` [PATCH v9 2/2] leds: as3668: Driver for the ams Osram 4-channel i2c LED driver Lukas Timmermann 1 sibling, 0 replies; 4+ messages in thread From: Lukas Timmermann @ 2025-10-14 15:26 UTC (permalink / raw) To: lee, pavel, robh, krzk+dt, conor+dt Cc: linux-leds, devicetree, linux-kernel, linux, Krzysztof Kozlowski The bindings are incomplete, as the GPIO/Audio Input pin is still undocumented. The hardware used for testing this patch series does not allow modification, so the mentioned pin has been omitted. Signed-off-by: Lukas Timmermann <linux@timmermann.space> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> --- .../devicetree/bindings/leds/ams,as3668.yaml | 74 +++++++++++++++++++ MAINTAINERS | 6 ++ 2 files changed, 80 insertions(+) create mode 100644 Documentation/devicetree/bindings/leds/ams,as3668.yaml diff --git a/Documentation/devicetree/bindings/leds/ams,as3668.yaml b/Documentation/devicetree/bindings/leds/ams,as3668.yaml new file mode 100644 index 000000000000..d1d73782da55 --- /dev/null +++ b/Documentation/devicetree/bindings/leds/ams,as3668.yaml @@ -0,0 +1,74 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/leds/ams,as3668.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Osram 4-channel i2c LED driver + +maintainers: + - Lukas Timmermann <linux@timmermann.space> + +description: + This IC can drive up to four separate LEDs. + Having four channels suggests it could be used with a single RGBW LED. + +properties: + compatible: + const: ams,as3668 + + reg: + maxItems: 1 + + "#address-cells": + const: 1 + + "#size-cells": + const: 0 + +patternProperties: + "^led@[0-3]$": + type: object + $ref: common.yaml# + unevaluatedProperties: false + + properties: + reg: + maxItems: 1 + +required: + - compatible + - reg + - "#address-cells" + - "#size-cells" + +additionalProperties: false + +examples: + - | + #include <dt-bindings/leds/common.h> + + i2c { + #address-cells = <1>; + #size-cells = <0>; + + led-controller@42 { + compatible = "ams,as3668"; + reg = <0x42>; + #address-cells = <1>; + #size-cells = <0>; + + led@0 { + reg = <0x0>; + function = LED_FUNCTION_STATUS; + color = <LED_COLOR_ID_RED>; + }; + + led@1 { + reg = <0x1>; + function = LED_FUNCTION_STATUS; + color = <LED_COLOR_ID_GREEN>; + }; + }; + }; + diff --git a/MAINTAINERS b/MAINTAINERS index c59316109e3f..091206c54c63 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3506,6 +3506,12 @@ L: linux-leds@vger.kernel.org S: Maintained F: drivers/leds/flash/leds-as3645a.c +AS3668 LED DRIVER +M: Lukas Timmermann <linux@timmermann.space> +L: linux-leds@vger.kernel.org +S: Maintained +F: Documentation/devicetree/bindings/leds/ams,as3668.yaml + ASAHI KASEI AK7375 LENS VOICE COIL DRIVER M: Tianshu Qiu <tian.shu.qiu@intel.com> L: linux-media@vger.kernel.org -- 2.51.0 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v9 2/2] leds: as3668: Driver for the ams Osram 4-channel i2c LED driver 2025-10-14 15:26 [PATCH v9 0/2] Support for Osram as3668 LED driver Lukas Timmermann 2025-10-14 15:26 ` [PATCH v9 1/2] dt-bindings: leds: Add new as3668 support Lukas Timmermann @ 2025-10-14 15:26 ` Lukas Timmermann 2025-10-23 14:18 ` Lee Jones 1 sibling, 1 reply; 4+ messages in thread From: Lukas Timmermann @ 2025-10-14 15:26 UTC (permalink / raw) To: lee, pavel, robh, krzk+dt, conor+dt Cc: linux-leds, devicetree, linux-kernel, linux 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 <linux@timmermann.space> --- MAINTAINERS | 1 + drivers/leds/Kconfig | 13 +++ drivers/leds/Makefile | 1 + drivers/leds/leds-as3668.c | 188 +++++++++++++++++++++++++++++++++++++ 4 files changed, 203 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 <linux@timmermann.space> 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 <tian.shu.qiu@intel.com> 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..2b7b776fe2f5 --- /dev/null +++ b/drivers/leds/leds-as3668.c @@ -0,0 +1,188 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Osram AMS AS3668 LED Driver IC + * + * Copyright (C) 2025 Lukas Timmermann <linux@timmermann.space> + */ + +#include <linux/bitfield.h> +#include <linux/i2c.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/uleds.h> + +#define AS3668_MAX_LEDS 4 +#define AS3668_EXPECTED_I2C_ADDR 0x42 + +/* Chip Ident */ + +#define AS3668_CHIP_ID1_REG 0x3e +#define AS3668_CHIP_ID 0xa5 + +/* 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_id; + + 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_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 '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, "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_CURRX_CONTROL_REG, 0); + if (err) + dev_err(&client->dev, "couldn't remove the 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 <linux@timmermann.space>"); +MODULE_DESCRIPTION("AS3668 LED driver"); +MODULE_LICENSE("GPL"); -- 2.51.0 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v9 2/2] leds: as3668: Driver for the ams Osram 4-channel i2c LED driver 2025-10-14 15:26 ` [PATCH v9 2/2] leds: as3668: Driver for the ams Osram 4-channel i2c LED driver Lukas Timmermann @ 2025-10-23 14:18 ` Lee Jones 0 siblings, 0 replies; 4+ messages in thread From: Lee Jones @ 2025-10-23 14:18 UTC (permalink / raw) To: Lukas Timmermann Cc: pavel, robh, krzk+dt, conor+dt, linux-leds, devicetree, linux-kernel On Tue, 14 Oct 2025, Lukas Timmermann wrote: > 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 <linux@timmermann.space> > --- > MAINTAINERS | 1 + > drivers/leds/Kconfig | 13 +++ > drivers/leds/Makefile | 1 + > drivers/leds/leds-as3668.c | 188 +++++++++++++++++++++++++++++++++++++ > 4 files changed, 203 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 <linux@timmermann.space> > 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 <tian.shu.qiu@intel.com> > 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 LEDS_OSRAM_AMS_AS3668 > + tristate "LED support for AMS AS3668" "Osram" > + depends on LEDS_CLASS > + depends on I2C > + help > + This option enables support for the AMS AS3668 LED controller. "Osram" > + 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..2b7b776fe2f5 > --- /dev/null > +++ b/drivers/leds/leds-as3668.c > @@ -0,0 +1,188 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Osram AMS AS3668 LED Driver IC > + * > + * Copyright (C) 2025 Lukas Timmermann <linux@timmermann.space> > + */ > + > +#include <linux/bitfield.h> > +#include <linux/i2c.h> > +#include <linux/leds.h> > +#include <linux/module.h> > +#include <linux/uleds.h> > + > +#define AS3668_MAX_LEDS 4 > +#define AS3668_EXPECTED_I2C_ADDR 0x42 > + > +/* Chip Ident */ > + > +#define AS3668_CHIP_ID1_REG 0x3e > +#define AS3668_CHIP_ID 0xa5 > + > +/* 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", The user isn't going to care about this stuff. "Failed to set brightness: %d" > + 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", "Failed to read 'reg' property" > + 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", "Unsupported LED: %d" > + 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_id; > + > + if (client->addr != AS3668_EXPECTED_I2C_ADDR) Expected is weird. Why are we trying to catch-out the consumer? If you already know what the I2C address is, just use that. > + 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 */ This comment is superfluous IMHO. The register name should tell us everything. > + chip_id = i2c_smbus_read_byte_data(client, AS3668_CHIP_ID1_REG); > + Remove this line. > + if (chip_id != AS3668_CHIP_ID) > + return dev_err_probe(&client->dev, -ENODEV, > + "expected chip id 0x%02x, got 0x%02x\n", "ID" > + 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 'on' */ Even if a specific LED wasn't requested? Are you sure that this doesn't have any drawbacks (power perhaps)? > + 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, "failed to write to the device\n"); > + > + return 0; > +} > + > +static void as3668_remove(struct i2c_client *client) > +{ > + int err; '\n' here. > + err = i2c_smbus_write_byte_data(client, AS3668_CURRX_CONTROL_REG, 0); > + if (err) > + dev_err(&client->dev, "couldn't remove the device\n"); This does not remove the device. "Failed to turn off the LEDs" > +} > + > +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 <linux@timmermann.space>"); > +MODULE_DESCRIPTION("AS3668 LED driver"); > +MODULE_LICENSE("GPL"); > -- > 2.51.0 > -- Lee Jones [李琼斯] ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2025-10-23 14:18 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2025-10-14 15:26 [PATCH v9 0/2] Support for Osram as3668 LED driver Lukas Timmermann 2025-10-14 15:26 ` [PATCH v9 1/2] dt-bindings: leds: Add new as3668 support Lukas Timmermann 2025-10-14 15:26 ` [PATCH v9 2/2] leds: as3668: Driver for the ams Osram 4-channel i2c LED driver Lukas Timmermann 2025-10-23 14:18 ` Lee Jones
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