From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4D8A72F999F; Tue, 2 Sep 2025 12:11:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756815096; cv=none; b=O61gScGkVN3g7/TOwDVwprT08eZTddFL0bjIzWmkV+4ES25m4j+nSB4967eGxlC6KBRPJPLR4AR3akBEenFhbJO806opfg52unySDS7m2Ka4Q9uVrjHnQVWhQuaALRoMLgrGBJs6InX0Xqa546dNHCaDSw/QhwOtX7VDB6mWOvU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756815096; c=relaxed/simple; bh=VYOX3TVwu2aQXNaJ1IWUZuDWAMGRimYYSnEF6bUBxzI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Sx4F0oe6RMgSpJFd7D5uQ8xs0nAs2n6j/e9BCKGnh5g5DqZsq8hpQeKHlr+eMcOO1YfbQLsUkuhJpdLWs+0xlyOes/C1t5Y9Nayoeh/IICdCbOeqPrfEr/EUQYrO/B+kf5/XyX4zdIfDg27eXOvJibLMtjw7EK/K285sXCWdV0g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tfoxuWMI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tfoxuWMI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C84FC4CEED; Tue, 2 Sep 2025 12:11:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756815095; bh=VYOX3TVwu2aQXNaJ1IWUZuDWAMGRimYYSnEF6bUBxzI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tfoxuWMIPd4UNzc/yxQqis3aUWDmrplaLHu9HZsuO5VgppUUWU2QePPO2IkYsSh7M FZnf5P1Dxcrn2ETcZ8DJVpqmKA3++717JJP1NhKWifNLaLkSZ361PF5jEVZUNmGZF0 9zWSmxyS3+EtZ3HpVZ5kQG3AUrF3XyJHIOmmfBpOhcR7itLc43gd3Z5uiQKPvRy+Bh 01kR4OobvUFdNpCoZ0vyhPF08SSJI1yTwazy++7LmhuDBEALJPdq2NNAmy2BZFVXzs 8TT4MAFJTuEVddnwXv0siAVIGgILg6Yiy+nOMKlnIoE41Tmrlj0flDvcGZEk4JlTV8 XqE11LoiZueAg== Date: Tue, 2 Sep 2025 13:11:30 +0100 From: Lee Jones To: Nam Tran Cc: pavel@kernel.org, rdunlap@infradead.org, christophe.jaillet@wanadoo.fr, krzk+dt@kernel.org, robh@kernel.org, conor+dt@kernel.org, corbet@lwn.net, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v13 RESEND 2/4] leds: add basic support for TI/National Semiconductor LP5812 LED Driver Message-ID: <20250902121130.GK2163762@google.com> References: <20250818012654.143058-1-trannamatk@gmail.com> <20250818012654.143058-3-trannamatk@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250818012654.143058-3-trannamatk@gmail.com> On Mon, 18 Aug 2025, Nam Tran wrote: > The LP5812 is a 4x3 matrix RGB LED driver with an autonomous animation > engine and time-cross-multiplexing (TCM) support for up to 12 LEDs or > 4 RGB LEDs. Each LED can be configured through the related registers > to realize vivid and fancy lighting effects. > > This patch adds minimal driver support for the LP5812, implementing > only the essential functionality: I2C communication with the device, > LED registration, brightness control in manual mode, and basic sysfs > interfaces for LED configuration and fault monitoring. > > Signed-off-by: Nam Tran > --- > MAINTAINERS | 4 + > drivers/leds/rgb/Kconfig | 13 + > drivers/leds/rgb/Makefile | 1 + > drivers/leds/rgb/leds-lp5812.c | 1086 ++++++++++++++++++++++++++++++++ > drivers/leds/rgb/leds-lp5812.h | 164 +++++ > 5 files changed, 1268 insertions(+) > create mode 100644 drivers/leds/rgb/leds-lp5812.c > create mode 100644 drivers/leds/rgb/leds-lp5812.h > > diff --git a/MAINTAINERS b/MAINTAINERS > index 99512777b890..c2e1c02e206d 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -24828,6 +24828,10 @@ M: Nam Tran > L: linux-leds@vger.kernel.org > S: Maintained > F: Documentation/devicetree/bindings/leds/ti,lp5812.yaml > +F: drivers/leds/rgb/Kconfig > +F: drivers/leds/rgb/Makefile > +F: drivers/leds/rgb/leds-lp5812.c > +F: drivers/leds/rgb/leds-lp5812.h > > TEXAS INSTRUMENTS' LB8864 LED BACKLIGHT DRIVER > M: Alexander Sverdlin > diff --git a/drivers/leds/rgb/Kconfig b/drivers/leds/rgb/Kconfig > index 222d943d826a..28ef4c487367 100644 > --- a/drivers/leds/rgb/Kconfig > +++ b/drivers/leds/rgb/Kconfig > @@ -26,6 +26,19 @@ config LEDS_KTD202X > To compile this driver as a module, choose M here: the module > will be called leds-ktd202x. > > +config LEDS_LP5812 > + tristate "LED support for Texas Instruments LP5812" > + depends on I2C > + help > + If you say Y here you get support for TI LP5812 LED driver. > + The LP5812 is a 4x3 matrix RGB LED driver with autonomous > + animation engine control. > + > + To compile this driver as a module, choose M here: the > + module will be called leds-lp5812. > + > + If unsure, say N. > + > config LEDS_NCP5623 > tristate "LED support for NCP5623" > depends on I2C > diff --git a/drivers/leds/rgb/Makefile b/drivers/leds/rgb/Makefile > index a501fd27f179..be45991f63f5 100644 > --- a/drivers/leds/rgb/Makefile > +++ b/drivers/leds/rgb/Makefile > @@ -2,6 +2,7 @@ > > obj-$(CONFIG_LEDS_GROUP_MULTICOLOR) += leds-group-multicolor.o > obj-$(CONFIG_LEDS_KTD202X) += leds-ktd202x.o > +obj-$(CONFIG_LEDS_LP5812) += leds-lp5812.o > obj-$(CONFIG_LEDS_NCP5623) += leds-ncp5623.o > obj-$(CONFIG_LEDS_PWM_MULTICOLOR) += leds-pwm-multicolor.o > obj-$(CONFIG_LEDS_QCOM_LPG) += leds-qcom-lpg.o > diff --git a/drivers/leds/rgb/leds-lp5812.c b/drivers/leds/rgb/leds-lp5812.c > new file mode 100644 > index 000000000000..fb5ea449761a > --- /dev/null > +++ b/drivers/leds/rgb/leds-lp5812.c > @@ -0,0 +1,1086 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * LP5812 LED driver > + * > + * Copyright (C) 2025 Texas Instruments > + * > + * Author: Jared Zhou > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "leds-lp5812.h" > + > +static int lp5812_write(struct lp5812_chip *chip, u16 reg, u8 val) > +{ > + struct device *dev = &chip->client->dev; > + struct i2c_msg msg; > + u8 buf[2]; > + u8 extracted_bits; What bits are being extracted? addr_low? > + int ret; > + > + /* Extract register address bits 9 and 8 for Address Byte 1 */ > + extracted_bits = (reg >> 8) & 0x03; Define all magic numbers throughout. This includes MASKs and SHIFTs. > + /* Prepare payload: Address Byte 2 (bits [7:0]) and value to write */ > + buf[0] = (u8)(reg & 0xFF); > + buf[1] = val; > + > + /* Construct I2C message for a write operation */ > + msg.addr = (chip->client->addr << 2) | extracted_bits; > + msg.flags = 0; > + msg.len = sizeof(buf); > + msg.buf = buf; > + > + ret = i2c_transfer(chip->client->adapter, &msg, 1); if (ret == 1) return 0; dev_err(dev, "I2C write error, ret=%d\n", ret); return ret < 0 ? ret : -EIO; > + if (ret != 1) { > + dev_err(dev, "I2C write error, ret=%d\n", ret); > + ret = ret < 0 ? ret : -EIO; > + } else { > + ret = 0; > + } > + > + return ret; > +} > + > +static int lp5812_read(struct lp5812_chip *chip, u16 reg, u8 *val) > +{ > + struct device *dev = &chip->client->dev; > + struct i2c_msg msgs[2]; > + u8 ret_val; > + u8 extracted_bits; > + u8 converted_reg; > + int ret; > + > + /* Extract register address bits 9 and 8 for Address Byte 1 */ > + extracted_bits = (reg >> 8) & 0x03; > + > + /* Lower 8 bits go in Address Byte 2 */ > + converted_reg = (u8)(reg & 0xFF); > + > + /* Prepare I2C write message to set register address */ > + msgs[0].addr = (chip->client->addr << 2) | extracted_bits; > + msgs[0].flags = 0; > + msgs[0].len = 1; > + msgs[0].buf = &converted_reg; > + > + /* Prepare I2C read message to retrieve register value */ > + msgs[1].addr = (chip->client->addr << 2) | extracted_bits; > + msgs[1].flags = I2C_M_RD; > + msgs[1].len = 1; > + msgs[1].buf = &ret_val; > + > + ret = i2c_transfer(chip->client->adapter, msgs, 2); As above. > + if (ret != 2) { > + dev_err(dev, "I2C read error, ret=%d\n", ret); > + *val = 0; > + ret = ret < 0 ? ret : -EIO; > + } else { > + /* Store the value retrieved from the hardware */ > + *val = ret_val; > + ret = 0; > + } > + > + return ret; > +} > + > +static int lp5812_read_tsd_config_status(struct lp5812_chip *chip, u8 *reg_val) > +{ > + return lp5812_read(chip, chip->cfg->reg_tsd_config_status.addr, reg_val); > +} > + > +static int lp5812_update_regs_config(struct lp5812_chip *chip) > +{ > + u8 reg_val; > + int ret; > + > + ret = lp5812_write(chip, chip->cfg->reg_cmd_update.addr, LP5812_UPDATE_CMD_VAL); > + if (ret) > + return ret; > + > + ret = lp5812_read_tsd_config_status(chip, ®_val); /* Save register value */ Save register value where? > + if (ret) > + return ret; > + > + return reg_val & 0x01; What bit is this? Please define it properly. > +} > + > +static int lp5812_fault_clear(struct lp5812_chip *chip, u8 value) > +{ > + > + if (value == 0) What do these values mean? Define? A switch() would be better. > + reg_val = LOD_CLEAR_VAL; > + else if (value == 1) > + reg_val = LSD_CLEAR_VAL; > + else if (value == 2) > + reg_val = TSD_CLEAR_VAL; > + else if (value == 3) > + reg_val = FAULT_CLEAR_ALL; > + else > + return -EINVAL; > + > + return lp5812_write(chip, chip->cfg->reg_reset.addr, reg_val); > +} > + > +static void set_mix_sel_led(struct lp5812_chip *chip, int mix_sel_led) What is a "mix_sel_led"? If forthcoming nomenclature can't be incorporated use comments. > +{ > + if (mix_sel_led == 0) > + chip->u_drive_mode.s_drive_mode.mix_sel_led_0 = 1; What are you doing here? Why not something like: chip->u_drive_mode.s_drive_mode.mix_sel_led[mix_sel_led] = true; Or if there is only one: chip->u_drive_mode.s_drive_mode.mix_sel_led = mix_sel_led; > + if (mix_sel_led == 1) > + chip->u_drive_mode.s_drive_mode.mix_sel_led_1 = 1; > + > + if (mix_sel_led == 2) > + chip->u_drive_mode.s_drive_mode.mix_sel_led_2 = 1; > + > + if (mix_sel_led == 3) > + chip->u_drive_mode.s_drive_mode.mix_sel_led_3 = 1; > +} > + > +static ssize_t parse_drive_mode(struct lp5812_chip *chip, char *str) > +{ > + char *sub_str; > + int tcm_scan_num, mix_scan_num, mix_sel_led, scan_oder[4], i, ret; > + > + chip->u_drive_mode.s_drive_mode.mix_sel_led_0 = 0; > + chip->u_drive_mode.s_drive_mode.mix_sel_led_1 = 0; > + chip->u_drive_mode.s_drive_mode.mix_sel_led_2 = 0; > + chip->u_drive_mode.s_drive_mode.mix_sel_led_3 = 0; > + > + sub_str = strsep(&str, ":"); This is totally unacceptable, sorry. One value per sysfs file. No parsing of weird and wonderful concats of data is allowed. I'll end the review here. -- Lee Jones [李琼斯]