From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751535AbdLAQe4 (ORCPT ); Fri, 1 Dec 2017 11:34:56 -0500 Received: from fllnx210.ext.ti.com ([198.47.19.17]:25096 "EHLO fllnx210.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750977AbdLAQey (ORCPT ); Fri, 1 Dec 2017 11:34:54 -0500 Subject: Re: [PATCH v5 2/2] leds: lm3692x: Introduce LM3692x dual string driver To: Jacek Anaszewski , , CC: , References: <20171130192239.7575-1-dmurphy@ti.com> <20171130192239.7575-2-dmurphy@ti.com> <80c6d487-7061-338c-adf0-a8c7d5439eb1@gmail.com> From: Dan Murphy Message-ID: <07d67e2b-72d9-c0db-1b8d-cd43e48b2847@ti.com> Date: Fri, 1 Dec 2017 10:34:36 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <80c6d487-7061-338c-adf0-a8c7d5439eb1@gmail.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jacek On 11/30/2017 03:38 PM, Jacek Anaszewski wrote: > Dan, > > Thanks for addressing my remarks. LED class device name > composition stills needs some tweaking, though. > > Please refer below to the piece of code in question. > > On 11/30/2017 08:22 PM, Dan Murphy wrote: >> Introducing the LM3692x Dual-String white LED driver. >> >> Data sheet is located >> http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf >> >> Signed-off-by: Dan Murphy >> --- >> v5 - Added OF dependency in Kconfig, added extra fault flag read to ensure that >> if a fault exists and it is not a artifact, fixed LED class label to be derived >> from either the DT child "label" node or create a label based on >> parent_node_name:led color:trigger, removed ifdef for CONFIG_OF and removed >> of_match_ptr - https://patchwork.kernel.org/patch/10081073/ >> >> v4 - Converted to devm led class register, changed MODULE_LICENSE to GPL v2, >> set the led name based on child node name or label entry, removed fault and >> returned read_buf for fault checking, added mutex_destroy to remove function, >> and removed LED_FULL - https://patchwork.kernel.org/patch/10060109/ >> v3 - Add missing Makefile and Kconfig from v1 and v2 - https://patchwork.kernel.org/patch/10060075/ >> v2 - Added data sheet link, fixed linuxdoc format, returned on failure in init >> routine, return on fault_check failure, updated brightness calculation and >> fixed capitalization issue - https://patchwork.kernel.org/patch/10056675/ >> >> drivers/leds/Kconfig | 7 + >> drivers/leds/Makefile | 1 + >> drivers/leds/leds-lm3692x.c | 396 ++++++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 404 insertions(+) >> create mode 100644 drivers/leds/leds-lm3692x.c >> >> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig >> index 318a28fd58fe..1d215b39cefd 100644 >> --- a/drivers/leds/Kconfig >> +++ b/drivers/leds/Kconfig >> @@ -137,6 +137,13 @@ config LEDS_LM3642 >> converter plus 1.5A constant current driver for a high-current >> white LED. >> >> +config LEDS_LM3692X >> + tristate "LED support for LM3692x Chips" >> + depends on LEDS_CLASS && I2C && OF >> + select REGMAP_I2C >> + help >> + This option enables support for the TI LM3692x family >> + of white LED string drivers used for backlighting. >> >> config LEDS_LOCOMO >> tristate "LED Support for Locomo device" >> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile >> index a2a6b5a4f86d..987884a5b9a5 100644 >> --- a/drivers/leds/Makefile >> +++ b/drivers/leds/Makefile >> @@ -74,6 +74,7 @@ obj-$(CONFIG_LEDS_PM8058) += leds-pm8058.o >> obj-$(CONFIG_LEDS_MLXCPLD) += leds-mlxcpld.o >> obj-$(CONFIG_LEDS_NIC78BX) += leds-nic78bx.o >> obj-$(CONFIG_LEDS_MT6323) += leds-mt6323.o >> +obj-$(CONFIG_LEDS_LM3692X) += leds-lm3692x.o >> >> # LED SPI Drivers >> obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o >> diff --git a/drivers/leds/leds-lm3692x.c b/drivers/leds/leds-lm3692x.c >> new file mode 100644 >> index 000000000000..70c974e06bd7 >> --- /dev/null >> +++ b/drivers/leds/leds-lm3692x.c >> @@ -0,0 +1,396 @@ >> +/* >> + * TI lm3692x LED Driver >> + * >> + * Copyright (C) 2017 Texas Instruments >> + * >> + * Author: Dan Murphy >> + * >> + * This program is free software; you can redistribute it and/or >> + * modify it under the terms of the GNU General Public License >> + * version 2 as published by the Free Software Foundation. >> + * >> + * Data sheet is located >> + * http://www.ti.com/lit/ds/snvsa29/snvsa29.pdf >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#define LM3692X_REV 0x0 >> +#define LM3692X_RESET 0x1 >> +#define LM3692X_EN 0x10 >> +#define LM3692X_BRT_CTRL 0x11 >> +#define LM3692X_PWM_CTRL 0x12 >> +#define LM3692X_BOOST_CTRL 0x13 >> +#define LM3692X_AUTO_FREQ_HI 0x15 >> +#define LM3692X_AUTO_FREQ_LO 0x16 >> +#define LM3692X_BL_ADJ_THRESH 0x17 >> +#define LM3692X_BRT_LSB 0x18 >> +#define LM3692X_BRT_MSB 0x19 >> +#define LM3692X_FAULT_CTRL 0x1e >> +#define LM3692X_FAULT_FLAGS 0x1f >> + >> +#define LM3692X_SW_RESET BIT(0) >> +#define LM3692X_DEVICE_EN BIT(0) >> +#define LM3692X_LED1_EN BIT(1) >> +#define LM3692X_LED2_EN BIT(2) >> + >> +/* Brightness Control Bits */ >> +#define LM3692X_BL_ADJ_POL BIT(0) >> +#define LM3692X_RAMP_RATE_125us 0x00 >> +#define LM3692X_RAMP_RATE_250us BIT(1) >> +#define LM3692X_RAMP_RATE_500us BIT(2) >> +#define LM3692X_RAMP_RATE_1ms (BIT(1) | BIT(2)) >> +#define LM3692X_RAMP_RATE_2ms BIT(3) >> +#define LM3692X_RAMP_RATE_4ms (BIT(3) | BIT(1)) >> +#define LM3692X_RAMP_RATE_8ms (BIT(2) | BIT(3)) >> +#define LM3692X_RAMP_RATE_16ms (BIT(1) | BIT(2) | BIT(3)) >> +#define LM3692X_RAMP_EN BIT(4) >> +#define LM3692X_BRHT_MODE_REG 0x00 >> +#define LM3692X_BRHT_MODE_PWM BIT(5) >> +#define LM3692X_BRHT_MODE_MULTI_RAMP BIT(6) >> +#define LM3692X_BRHT_MODE_RAMP_MULTI (BIT(5) | BIT(6)) >> +#define LM3692X_MAP_MODE_EXP BIT(7) >> + >> +/* PWM Register Bits */ >> +#define LM3692X_PWM_FILTER_100 BIT(0) >> +#define LM3692X_PWM_FILTER_150 BIT(1) >> +#define LM3692X_PWM_FILTER_200 (BIT(0) | BIT(1)) >> +#define LM3692X_PWM_HYSTER_1LSB BIT(2) >> +#define LM3692X_PWM_HYSTER_2LSB BIT(3) >> +#define LM3692X_PWM_HYSTER_3LSB (BIT(3) | BIT(2)) >> +#define LM3692X_PWM_HYSTER_4LSB BIT(4) >> +#define LM3692X_PWM_HYSTER_5LSB (BIT(4) | BIT(2)) >> +#define LM3692X_PWM_HYSTER_6LSB (BIT(4) | BIT(3)) >> +#define LM3692X_PWM_POLARITY BIT(5) >> +#define LM3692X_PWM_SAMP_4MHZ BIT(6) >> +#define LM3692X_PWM_SAMP_24MHZ BIT(7) >> + >> +/* Boost Control Bits */ >> +#define LM3692X_OCP_PROT_1A BIT(0) >> +#define LM3692X_OCP_PROT_1_25A BIT(1) >> +#define LM3692X_OCP_PROT_1_5A (BIT(0) | BIT(1)) >> +#define LM3692X_OVP_21V BIT(2) >> +#define LM3692X_OVP_25V BIT(3) >> +#define LM3692X_OVP_29V (BIT(2) | BIT(3)) >> +#define LM3692X_MIN_IND_22UH BIT(4) >> +#define LM3692X_BOOST_SW_1MHZ BIT(5) >> +#define LM3692X_BOOST_SW_NO_SHIFT BIT(6) >> + >> +/* Fault Control Bits */ >> +#define LM3692X_FAULT_CTRL_OVP BIT(0) >> +#define LM3692X_FAULT_CTRL_OCP BIT(1) >> +#define LM3692X_FAULT_CTRL_TSD BIT(2) >> +#define LM3692X_FAULT_CTRL_OPEN BIT(3) >> + >> +/* Fault Flag Bits */ >> +#define LM3692X_FAULT_FLAG_OVP BIT(0) >> +#define LM3692X_FAULT_FLAG_OCP BIT(1) >> +#define LM3692X_FAULT_FLAG_TSD BIT(2) >> +#define LM3692X_FAULT_FLAG_SHRT BIT(3) >> +#define LM3692X_FAULT_FLAG_OPEN BIT(4) >> + >> +/** >> + * struct lm3692x_led - >> + * @lock - Lock for reading/writing the device >> + * @client - Pointer to the I2C client >> + * @led_dev - LED class device pointer >> + * @regmap - Devices register map >> + * @enable_gpio - VDDIO/EN gpio to enable communication interface >> + * @regulator - LED supply regulator pointer >> + * @label - LED label >> + */ >> +struct lm3692x_led { >> + struct mutex lock; >> + struct i2c_client *client; >> + struct led_classdev led_dev; >> + struct regmap *regmap; >> + struct gpio_desc *enable_gpio; >> + struct regulator *regulator; >> + char label[32]; >> +}; >> + >> +static const struct reg_default lm3692x_reg_defs[] = { >> + {LM3692X_EN, 0xf}, >> + {LM3692X_BRT_CTRL, 0x61}, >> + {LM3692X_PWM_CTRL, 0x73}, >> + {LM3692X_BOOST_CTRL, 0x6f}, >> + {LM3692X_AUTO_FREQ_HI, 0x0}, >> + {LM3692X_AUTO_FREQ_LO, 0x0}, >> + {LM3692X_BL_ADJ_THRESH, 0x0}, >> + {LM3692X_BRT_LSB, 0x7}, >> + {LM3692X_BRT_MSB, 0xff}, >> + {LM3692X_FAULT_CTRL, 0x7}, >> +}; >> + >> +static const struct regmap_config lm3692x_regmap_config = { >> + .reg_bits = 8, >> + .val_bits = 8, >> + >> + .max_register = LM3692X_FAULT_FLAGS, >> + .reg_defaults = lm3692x_reg_defs, >> + .num_reg_defaults = ARRAY_SIZE(lm3692x_reg_defs), >> + .cache_type = REGCACHE_RBTREE, >> +}; >> + >> +static int lm3692x_fault_check(struct lm3692x_led *led) >> +{ >> + int ret; >> + unsigned int read_buf; >> + >> + ret = regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); >> + if (ret) >> + return ret; >> + >> + if (read_buf) >> + dev_err(&led->client->dev, "Detected a fault 0x%X\n", read_buf); >> + >> + /* The first read may clear the fault. Check again to see if the fault >> + * still exits and return that value. >> + */ >> + regmap_read(led->regmap, LM3692X_FAULT_FLAGS, &read_buf); >> + if (read_buf) >> + dev_err(&led->client->dev, "Second read of fault flags 0x%X\n", >> + read_buf); >> + >> + return read_buf; >> +} >> + >> +static int lm3692x_brightness_set(struct led_classdev *led_cdev, >> + enum led_brightness brt_val) >> +{ >> + struct lm3692x_led *led = >> + container_of(led_cdev, struct lm3692x_led, led_dev); >> + int ret; >> + int led_brightness_lsb = (brt_val >> 5); >> + >> + mutex_lock(&led->lock); >> + >> + ret = lm3692x_fault_check(led); >> + if (ret) { >> + dev_err(&led->client->dev, "Cannot read/clear faults\n"); >> + goto out; >> + } >> + >> + ret = regmap_write(led->regmap, LM3692X_BRT_MSB, brt_val); >> + if (ret) { >> + dev_err(&led->client->dev, "Cannot write MSB\n"); >> + goto out; >> + } >> + >> + ret = regmap_write(led->regmap, LM3692X_BRT_LSB, led_brightness_lsb); >> + if (ret) { >> + dev_err(&led->client->dev, "Cannot write LSB\n"); >> + goto out; >> + } >> +out: >> + mutex_unlock(&led->lock); >> + return ret; >> +} >> + >> +static int lm3692x_init(struct lm3692x_led *led) >> +{ >> + int ret; >> + >> + if (led->regulator) { >> + ret = regulator_enable(led->regulator); >> + if (ret) { >> + dev_err(&led->client->dev, >> + "Failed to enable regulator\n"); >> + return ret; >> + } >> + } >> + >> + if (led->enable_gpio) >> + gpiod_direction_output(led->enable_gpio, 1); >> + >> + ret = lm3692x_fault_check(led); >> + if (ret) { >> + dev_err(&led->client->dev, "Cannot read/clear faults\n"); >> + goto out; >> + } >> + >> + ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, 0x00); >> + if (ret) >> + goto out; >> + >> + /* >> + * For glitch free operation, the following data should >> + * only be written while device enable bit is 0 >> + * per Section 7.5.14 of the data sheet >> + */ >> + ret = regmap_write(led->regmap, LM3692X_PWM_CTRL, >> + LM3692X_PWM_FILTER_100 | LM3692X_PWM_SAMP_24MHZ); >> + if (ret) >> + goto out; >> + >> + ret = regmap_write(led->regmap, LM3692X_BOOST_CTRL, >> + LM3692X_BRHT_MODE_RAMP_MULTI | >> + LM3692X_BL_ADJ_POL | >> + LM3692X_RAMP_RATE_250us); >> + if (ret) >> + goto out; >> + >> + ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_HI, 0x00); >> + if (ret) >> + goto out; >> + >> + ret = regmap_write(led->regmap, LM3692X_AUTO_FREQ_LO, 0x00); >> + if (ret) >> + goto out; >> + >> + ret = regmap_write(led->regmap, LM3692X_BL_ADJ_THRESH, 0x00); >> + if (ret) >> + goto out; >> + >> + ret = regmap_write(led->regmap, LM3692X_BRT_CTRL, >> + LM3692X_BL_ADJ_POL | LM3692X_PWM_HYSTER_4LSB); >> + if (ret) >> + goto out; >> + >> + return ret; >> +out: >> + dev_err(&led->client->dev, "Fail writing initialization values\n"); >> + >> + if (led->enable_gpio) >> + gpiod_direction_output(led->enable_gpio, 0); >> + >> + if (led->regulator) { >> + ret = regulator_disable(led->regulator); >> + if (ret) >> + dev_err(&led->client->dev, >> + "Failed to disable regulator\n"); >> + } >> + >> + return ret; >> +} >> + >> +static int lm3692x_probe(struct i2c_client *client, >> + const struct i2c_device_id *id) >> +{ >> + int ret; >> + struct lm3692x_led *led; >> + struct device_node *np = client->dev.of_node; >> + struct device_node *child_node; >> + const char *name; >> + char trigger[32] = ":none"; >> + >> + led = devm_kzalloc(&client->dev, sizeof(*led), GFP_KERNEL); >> + if (!led) >> + return -ENOMEM; >> + >> + for_each_available_child_of_node(np, child_node) { >> + led->led_dev.default_trigger = of_get_property(child_node, >> + "linux,default-trigger", >> + NULL); >> + >> + if (led->led_dev.default_trigger) >> + snprintf(trigger, sizeof(trigger), ":%s", >> + led->led_dev.default_trigger); > > Let's not use trigger name for the LED function name. Trigger cannot > define LED function, since LED class device can be assigned any > other trigger at any time. Please drop above "if" statement. > >> + >> + ret = of_property_read_string(child_node, "label", &name); >> + if (!ret) >> + strlcpy(led->label, name, sizeof(led->label)); >> + else >> + snprintf(led->label, sizeof(led->label), "%s:white%s", >> + np->name, trigger); > > You'll need to change label in your DT bindings example to: > > label = "white:backlight_cluster" > > and after that the LED class device name should be constructed like > below. Sorry for not being precise enough. > > ret = of_property_read_string(child_node, "label", &name); > if (!ret) > snprintf(led->label, sizeof(led->label), "%s:%s", > np->name, name) > else > snprintf(led->label, sizeof(led->label), > "%s:white:backlight_cluster", > np->name) > > You could even make this a generic LED core function e.g. > > void of_led_compose_name(struct device_node *parent, > struct device_node *child) > New LED class API coming your way in v6 along with some other driver changes for examples Dan > It's up to you, I'm going to do that anyway when I'll find a moment. > >> + }; >> + >> + led->enable_gpio = devm_gpiod_get_optional(&client->dev, >> + "enable", GPIOD_OUT_LOW); >> + if (IS_ERR(led->enable_gpio)) { >> + ret = PTR_ERR(led->enable_gpio); >> + dev_err(&client->dev, "Failed to get enable gpio: %d\n", ret); >> + return ret; >> + } >> + >> + led->regulator = devm_regulator_get(&client->dev, "vled"); >> + if (IS_ERR(led->regulator)) >> + led->regulator = NULL; >> + >> + led->client = client; >> + led->led_dev.name = led->label; >> + led->led_dev.brightness_set_blocking = lm3692x_brightness_set; >> + >> + mutex_init(&led->lock); >> + >> + i2c_set_clientdata(client, led); >> + >> + led->regmap = devm_regmap_init_i2c(client, &lm3692x_regmap_config); >> + if (IS_ERR(led->regmap)) { >> + ret = PTR_ERR(led->regmap); >> + dev_err(&client->dev, "Failed to allocate register map: %d\n", >> + ret); >> + return ret; >> + } >> + >> + ret = lm3692x_init(led); >> + if (ret) >> + return ret; >> + >> + ret = devm_led_classdev_register(&client->dev, &led->led_dev); >> + if (ret) { >> + dev_err(&client->dev, "led register err: %d\n", ret); >> + return ret; >> + } >> + >> + return 0; >> +} >> + >> +static int lm3692x_remove(struct i2c_client *client) >> +{ >> + struct lm3692x_led *led = i2c_get_clientdata(client); >> + int ret; >> + >> + if (led->enable_gpio) >> + gpiod_direction_output(led->enable_gpio, 0); >> + >> + if (led->regulator) { >> + ret = regulator_disable(led->regulator); >> + if (ret) >> + dev_err(&led->client->dev, >> + "Failed to disable regulator\n"); >> + } >> + >> + mutex_destroy(&led->lock); >> + >> + return 0; >> +} >> + >> +static const struct i2c_device_id lm3692x_id[] = { >> + { "lm36922", 0 }, >> + { "lm36923", 1 }, >> + { } >> +}; >> +MODULE_DEVICE_TABLE(i2c, lm3692x_id); >> + >> +static const struct of_device_id of_lm3692x_leds_match[] = { >> + { .compatible = "ti,lm36922", }, >> + { .compatible = "ti,lm36923", }, >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(of, of_lm3692x_leds_match); >> + >> +static struct i2c_driver lm3692x_driver = { >> + .driver = { >> + .name = "lm3692x", >> + .of_match_table = of_lm3692x_leds_match, >> + }, >> + .probe = lm3692x_probe, >> + .remove = lm3692x_remove, >> + .id_table = lm3692x_id, >> +}; >> +module_i2c_driver(lm3692x_driver); >> + >> +MODULE_DESCRIPTION("Texas Instruments LM3692X LED driver"); >> +MODULE_AUTHOR("Dan Murphy "); >> +MODULE_LICENSE("GPL v2"); >> > -- ------------------ Dan Murphy