From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailout1.w1.samsung.com ([210.118.77.11]:41814 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751970AbcJJJlp (ORCPT ); Mon, 10 Oct 2016 05:41:45 -0400 Subject: Re: [PATCH 07/10] leds: i2cs: Add I2CS FPGA leds driver To: Pantelis Antoniou , Lee Jones Cc: Linus Walleij , Alexandre Courbot , Rob Herring , Mark Rutland , Frank Rowand , Wolfram Sang , Richard Purdie , Jean Delvare , Peter Rosin , Avirup Banerjee , Georgi Vlaev , Guenter Roeck , JawaharBalaji Thirumalaisamy , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org, linux-leds@vger.kernel.org, linux-hwmon@vger.kernel.org From: Jacek Anaszewski Message-id: <31a98da5-d5f1-f86c-ee98-6fd0707e6180@samsung.com> Date: Mon, 10 Oct 2016 11:41:34 +0200 MIME-version: 1.0 In-reply-to: <1475853669-22480-8-git-send-email-pantelis.antoniou@konsulko.com> Content-type: text/plain; charset=windows-1252; format=flowed Content-transfer-encoding: 7bit References: <1475853669-22480-1-git-send-email-pantelis.antoniou@konsulko.com> <1475853669-22480-8-git-send-email-pantelis.antoniou@konsulko.com> Sender: linux-hwmon-owner@vger.kernel.org List-Id: linux-hwmon@vger.kernel.org Hi Pantelis, Thanks for the patch. Please find my comments in the code below. On 10/07/2016 05:21 PM, Pantelis Antoniou wrote: > From: Georgi Vlaev > > Add support for the FRU faceplate status LEDs (OK, FAIL, > ACTIVE, STANDBY) controlled by the Juniper I2CS FPGA. This > driver is a jnx-i2cs-core client. > > Signed-off-by: Georgi Vlaev > [Ported from Juniper kernel] > Signed-off-by: Pantelis Antoniou > --- > drivers/leds/Kconfig | 9 ++ > drivers/leds/Makefile | 1 + > drivers/leds/leds-jnx-i2cs.c | 219 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 229 insertions(+) > create mode 100644 drivers/leds/leds-jnx-i2cs.c > > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index 7a628c6..45c6612 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -659,6 +659,15 @@ config LEDS_MLXCPLD > This option enabled support for the LEDs on the Mellanox > boards. Say Y to enabled these. > > +config LEDS_JNX_I2CS > + tristate "LED support for the Juniper Networks I2CS FPGA" > + depends on LEDS_CLASS && I2C > + select REGMAP_I2C > + help > + This option enables support for the FRU faceplate status > + LEDs (OK, FAIL, ACTIVE, STANDBY) controlled by the Juniper > + I2CS FPGA. > + > comment "LED Triggers" > source "drivers/leds/trigger/Kconfig" > > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile > index 3965070..1ce2d0b 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -71,6 +71,7 @@ obj-$(CONFIG_LEDS_IS31FL319X) += leds-is31fl319x.o > obj-$(CONFIG_LEDS_IS31FL32XX) += leds-is31fl32xx.o > obj-$(CONFIG_LEDS_PM8058) += leds-pm8058.o > obj-$(CONFIG_LEDS_MLXCPLD) += leds-mlxcpld.o > +obj-$(CONFIG_LEDS_JNX_I2CS) += leds-jnx-i2cs.o > > # LED SPI Drivers > obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o > diff --git a/drivers/leds/leds-jnx-i2cs.c b/drivers/leds/leds-jnx-i2cs.c > new file mode 100644 > index 0000000..c2d7274 > --- /dev/null > +++ b/drivers/leds/leds-jnx-i2cs.c > @@ -0,0 +1,219 @@ > +/* > + * Juniper Networks I2CS FPGA LEDs driver > + * > + * Copyright (C) 2016 Juniper Networks > + * Author: Georgi Vlaev > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include Please arrange include directives in alphabetical order. > +#define FRU_LEDS 4 /* Total LEDs (active, fail, ok, standby) */ > +#define HW_BLINK_LEDS 3 /* LEDs with hw blink cap (standby not supported) */ > + > +/* > + * I2CS fru_led [0x12] > + * > + * bit 6 | bit 5 | bit 4 |... | bit 0 > + * blink_ok|blink_fail|blink_act|led_standby|led_ok|led_fail|led_act > + */ > + > +/* TODO: Use the regmap from the parent MFD */ Isn't it a good moment to address that? > +static struct regmap_config i2cs_leds_regmap_config = { > + .reg_bits = 8, > + .val_bits = 8, > + .max_register = I2CS_SPARE_OE, > +}; > + > +struct i2cs_led { > + struct led_classdev lc; Most drivers use led_cdev or cdev name for it. It is more informative and improves readability. > + struct regmap *regmap; > + struct work_struct work; > + int blink; > + int on; > + int bit; > +}; > + > +struct i2cs_led_data { > + int num_leds; > + struct i2cs_led *leds; > +}; > + > +static void jnx_i2cs_leds_work(struct work_struct *work) > +{ > + struct i2cs_led *led = container_of(work, struct i2cs_led, work); > + > + int mask = (BIT(led->bit) << 4) | BIT(led->bit); > + int value = ((led->blink << led->bit) << 4) | (led->on << led->bit); > + > + regmap_update_bits(led->regmap, I2CS_FRU_LED, mask, value & 0x7f); > +} If you used brightness_set_blocking op instead of brightness_set, then you could get rid of the in-driver work queue. > + > +static void jnx_i2cs_leds_brightness_set(struct led_classdev *lc, > + enum led_brightness brightness) > +{ > + struct i2cs_led *led = container_of(lc, struct i2cs_led, lc); > + > + led->on = (brightness != LED_OFF); > + led->blink = 0; /* always turn off hw blink on brightness_set() */ Some time ago we changed brightness setting semantics when blinking is on. Now setting any brightness > 0 shouldn't disable blinking. Following commit provides the details: 7cfe749fad51 ("leds: core: Fix brightness setting upon hardware blinking enabled") It seems that the hardware supports only one brightness level. In such a case I'd return immediately if the LED is on and brightness to be set is 1. > + schedule_work(&led->work); > +} > + > +static int jnx_i2cs_leds_blink_set(struct led_classdev *lc, > + unsigned long *delay_on, > + unsigned long *delay_off) > +{ > + struct i2cs_led *led = container_of(lc, struct i2cs_led, lc); > + > + led->blink = (*delay_on > 0); blink_set op should fail if hardware doesn't support delay_on or delay_off periods. I lets the LED core to apply software blink fallback. > + led->on = led->blink; /* 'on' bit should be set if blinking */ > + schedule_work(&led->work); > + > + return 0; > +} > + > +static int jnx_i2cs_leds_init_one(struct device *dev, struct device_node *np, > + struct i2cs_led_data *ild, > + struct regmap *regmap, int num) > +{ > + struct i2cs_led *led; > + const char *string; > + bool hw_blink; > + int ret; > + u32 reg; > + > + ret = of_property_read_u32(np, "reg", ®); > + if (ret || reg >= FRU_LEDS) > + return -ENODEV; > + > + led = &ild->leds[num]; > + led->bit = reg; > + led->regmap = regmap; > + > + if (!of_property_read_string(np, "label", &string)) > + led->lc.name = string; > + else > + led->lc.name = np->name; > + > + if (!of_property_read_string(np, "linux,default-trigger", &string)) > + led->lc.default_trigger = string; > + > + led->lc.brightness = LED_OFF; > + led->lc.brightness_set = jnx_i2cs_leds_brightness_set; You need also: led->lc.max_brightness = 1; > + if (led->bit <= HW_BLINK_LEDS) { > + hw_blink = of_property_read_bool(np, "hw-blink"); > + if (hw_blink) > + led->lc.blink_set = jnx_i2cs_leds_blink_set; > + } > + > + ret = devm_led_classdev_register(dev, &led->lc); > + if (ret) > + return ret; > + > + INIT_WORK(&led->work, jnx_i2cs_leds_work); > + > + return 0; > +} > + > +static int jnx_i2cs_leds_of_init(struct device *dev, struct i2cs_led_data *ild) > +{ > + struct device_node *child, *np = dev->of_node; > + struct regmap *regmap; > + struct i2c_client *client; > + int ret, num_leds, i = 0; > + > + if (!dev->parent) > + return -ENODEV; > + > + client = i2c_verify_client(dev->parent); > + if (!client) > + return -ENODEV; > + > + regmap = devm_regmap_init_i2c(client, &i2cs_leds_regmap_config); > + if (IS_ERR(regmap)) { > + dev_err(dev, "Failed to allocate register map\n"); > + return PTR_ERR(regmap); > + } > + > + num_leds = of_get_child_count(np); > + if (!num_leds || num_leds > FRU_LEDS) > + return -ENODEV; > + > + ild->num_leds = num_leds; > + ild->leds = devm_kzalloc(dev, sizeof(struct i2cs_led) * num_leds, > + GFP_KERNEL); > + if (!ild->leds) > + return -ENOMEM; > + > + for_each_child_of_node(np, child) { > + ret = jnx_i2cs_leds_init_one(dev, child, ild, regmap, i++); > + if (ret) > + return ret; of_node_put(child) should be called on error to avoid memory leak. > + } > + > + return 0; > +} > + > +static int jnx_i2cs_leds_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct i2cs_led_data *ild; > + int ret; > + > + ild = devm_kzalloc(dev, sizeof(*ild), GFP_KERNEL); > + if (!ild) > + return -ENOMEM; > + > + ret = jnx_i2cs_leds_of_init(dev, ild); > + if (ret < 0) > + return ret; > + > + platform_set_drvdata(pdev, ild); > + > + return 0; > +} > + > +static int jnx_i2cs_leds_remove(struct platform_device *pdev) > +{ > + struct i2cs_led_data *ild = platform_get_drvdata(pdev); > + int i; > + > + for (i = 0; i < ild->num_leds; i++) { > + devm_led_classdev_unregister(&pdev->dev, &ild->leds[i].lc); This is redundant. > + cancel_work_sync(&ild->leds[i].work); > + } > + > + return 0; > +} This function will be redundant after removing work queue. > +static const struct of_device_id jnx_i2cs_leds_match[] = { > + { .compatible = "jnx,leds-i2cs", }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, jnx_i2cs_leds_match); > + > +static struct platform_driver jnx_i2cs_leds_driver = { > + .driver = { > + .name = "leds-i2cs", > + .of_match_table = jnx_i2cs_leds_match, > + }, > + .probe = jnx_i2cs_leds_probe, > + .remove = jnx_i2cs_leds_remove, > +}; > + > +module_platform_driver(jnx_i2cs_leds_driver); > + > +MODULE_DESCRIPTION("Juniper Networks I2CS leds driver"); > +MODULE_AUTHOR("Georgi Vlaev "); > +MODULE_LICENSE("GPL"); > -- Best regards, Jacek Anaszewski