Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758049AbaLKOZq (ORCPT ); Thu, 11 Dec 2014 09:25:46 -0500 Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:45822 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754498AbaLKOZo (ORCPT ); Thu, 11 Dec 2014 09:25:44 -0500 Date: Thu, 11 Dec 2014 16:16:48 +0200 From: Sakari Ailus To: Jacek Anaszewski Cc: linux-leds@vger.kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, kyungmin.park@samsung.com, b.zolnierkie@samsung.com, pavel@ucw.cz, cooloney@gmail.com, rpurdie@rpsys.net, s.nawrocki@samsung.com, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org Subject: Re: [PATCH/RFC v9 08/19] leds: Add driver for AAT1290 current regulator Message-ID: <20141211141648.GR15559@valkosipuli.retiisi.org.uk> References: <1417622814-10845-1-git-send-email-j.anaszewski@samsung.com> <1417622814-10845-9-git-send-email-j.anaszewski@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1417622814-10845-9-git-send-email-j.anaszewski@samsung.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jacek, On Wed, Dec 03, 2014 at 05:06:43PM +0100, Jacek Anaszewski wrote: > This patch adds a driver for the 1.5A Step-Up Current Regulator > for Flash LEDs. The device is programmed through a Skyworks proprietary > AS2Cwire serial digital interface. > > Signed-off-by: Jacek Anaszewski > Acked-by: Kyungmin Park > Cc: Bryan Wu > Cc: Richard Purdie > --- > drivers/leds/Kconfig | 7 + > drivers/leds/Makefile | 1 + > drivers/leds/leds-aat1290.c | 413 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 421 insertions(+) > create mode 100644 drivers/leds/leds-aat1290.c > > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index 2e66d55..ec4b78c 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -39,6 +39,13 @@ config LEDS_88PM860X > This option enables support for on-chip LED drivers found on Marvell > Semiconductor 88PM8606 PMIC. > > +config LEDS_AAT1290 > + tristate "LED support for the AAT1290" > + depends on LEDS_CLASS_FLASH > + depends on OF > + help > + This option enables support for the LEDs on the AAT1290. > + > config LEDS_LM3530 > tristate "LCD Backlight driver for LM3530" > depends on LEDS_CLASS > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile > index 57ca62b..b802251 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -7,6 +7,7 @@ obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o > > # LED Platform Drivers > obj-$(CONFIG_LEDS_88PM860X) += leds-88pm860x.o > +obj-$(CONFIG_LEDS_AAT1290) += leds-aat1290.o > obj-$(CONFIG_LEDS_BD2802) += leds-bd2802.o > obj-$(CONFIG_LEDS_LOCOMO) += leds-locomo.o > obj-$(CONFIG_LEDS_LM3530) += leds-lm3530.o > diff --git a/drivers/leds/leds-aat1290.c b/drivers/leds/leds-aat1290.c > new file mode 100644 > index 0000000..15d969b > --- /dev/null > +++ b/drivers/leds/leds-aat1290.c > @@ -0,0 +1,413 @@ > +/* > + * LED Flash class driver for the AAT1290 > + * 1.5A Step-Up Current Regulator for Flash LEDs > + * > + * Copyright (C) 2014, Samsung Electronics Co., Ltd. > + * Author: Jacek Anaszewski > + * > + * 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. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include Alphabetic order, please. > + > +#define AAT1290_MOVIE_MODE_CURRENT_ADDR 17 > +#define AAT1290_FLASH_SAFETY_TIMER_ADDR 18 > +#define AAT1290_MOVIE_MODE_CONFIG_ADDR 19 > +#define AAT1290_MM_CURRENT_RATIO_ADDR 20 > +#define AAT1290_LATCH_TIME_US 500 > +#define AAT1290_EN_SET_TICK_TIME_US 1 > +#define AAT1290_MOVIE_MODE_OFF 1 > +#define AAT1290_MOVIE_MODE_ON 3 > +#define AAT1290_MAX_MM_CURR_PERCENT_0 16 > +#define AAT1290_MAX_MM_CURR_PERCENT_100 1 > +#define AAT1290_FLASH_TM_NUM_LEVELS 16 It'd be nice to arrange register bit definitions next to the register address they're related to. That makes this a lot more readable. Timeouts separately as well. Please also align the values on the right to the same column. I think they mostly are, but at least AAT1290_MAX_MM_CURR_PERCENT_100 uses space instead of a tab. > +#define AAT1290_MM_TO_FL_1_92 1 > +#define AAT1290_MM_TO_FL_3_7 2 > +#define AAT1290_MM_TO_FL_5_5 3 > +#define AAT1290_MM_TO_FL_7_3 4 > +#define AAT1290_MM_TO_FL_9 5 > +#define AAT1290_MM_TO_FL_10_7 6 > +#define AAT1290_MM_TO_FL_12_4 7 > +#define AAT1290_MM_TO_FL_14 8 > +#define AAT1290_MM_TO_FL_15_9 9 > +#define AAT1290_MM_TO_FL_17_5 10 > +#define AAT1290_MM_TO_FL_19_1 11 > +#define AAT1290_MM_TO_FL_20_8 12 > +#define AAT1290_MM_TO_FL_22_4 13 > +#define AAT1290_MM_TO_FL_24 14 > +#define AAT1290_MM_TO_FL_25_6 15 > +#define AAT1290_MM_TO_FL_OFF 16 > + > +struct aat1290_led_settings { > + struct led_flash_setting torch_brightness; > + struct led_flash_setting flash_brightness; > + struct led_flash_setting flash_timeout; > +}; > + > +struct aat1290_led { > + struct platform_device *pdev; > + struct mutex lock; > + > + struct led_classdev_flash ldev; > + > + int flen_gpio; > + int en_set_gpio; > + > + u32 max_flash_tm; > + bool movie_mode; > + > + char *label; > + unsigned int torch_brightness; > + unsigned int flash_timeout; > + struct work_struct work_brightness_set; > +}; > + > +static struct aat1290_led *ldev_to_led(struct led_classdev_flash *ldev) > +{ > + return container_of(ldev, struct aat1290_led, ldev); > +} > + > +static void aat1290_as2cwire_write(struct aat1290_led *led, int addr, int value) > +{ > + int i; > + > + gpio_set_value(led->flen_gpio, 0); > + gpio_set_value(led->en_set_gpio, 0); > + > + udelay(10); Could you use a #define for this as you are using for the rest? > + > + /* write address */ > + for (i = 0; i < addr; ++i) { > + udelay(AAT1290_EN_SET_TICK_TIME_US); > + gpio_set_value(led->en_set_gpio, 0); > + udelay(AAT1290_EN_SET_TICK_TIME_US); > + gpio_set_value(led->en_set_gpio, 1); > + } This is a very interesting approach to bus implementation. It's a bit like pulse dial on POTS. :-) > + > + udelay(AAT1290_LATCH_TIME_US); How precise does this need to be? Could you use usleep_range() instead? > + > + /* write data */ > + for (i = 0; i < value; ++i) { > + udelay(AAT1290_EN_SET_TICK_TIME_US); > + gpio_set_value(led->en_set_gpio, 0); > + udelay(AAT1290_EN_SET_TICK_TIME_US); > + gpio_set_value(led->en_set_gpio, 1); > + } > + > + udelay(AAT1290_LATCH_TIME_US); > +} > + > +static void aat1290_set_flash_safety_timer(struct aat1290_led *led, > + unsigned int micro_sec) > +{ > + struct led_classdev_flash *flash = &led->ldev; > + struct led_flash_setting *flash_tm = &flash->timeout; > + int flash_tm_reg = AAT1290_FLASH_TM_NUM_LEVELS - > + (micro_sec / flash_tm->step) + 1; > + > + aat1290_as2cwire_write(led, AAT1290_FLASH_SAFETY_TIMER_ADDR, > + flash_tm_reg); > +} > + > +static void aat1290_brightness_set(struct aat1290_led *led, > + enum led_brightness brightness) > +{ > + mutex_lock(&led->lock); > + > + if (brightness == 0) { > + gpio_set_value(led->flen_gpio, 0); > + gpio_set_value(led->en_set_gpio, 0); > + goto unlock; > + } > + > + if (!led->movie_mode) { > + aat1290_as2cwire_write(led, AAT1290_MM_CURRENT_RATIO_ADDR, > + AAT1290_MM_TO_FL_1_92); > + led->movie_mode = true; > + } > + > + aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CURRENT_ADDR, > + AAT1290_MAX_MM_CURR_PERCENT_0 - brightness); > + aat1290_as2cwire_write(led, AAT1290_MOVIE_MODE_CONFIG_ADDR, > + AAT1290_MOVIE_MODE_ON); > +unlock: > + mutex_unlock(&led->lock); > +} > + > +/* LED subsystem callbacks */ > + > +static void aat1290_brightness_set_work(struct work_struct *work) > +{ > + struct aat1290_led *led = > + container_of(work, struct aat1290_led, work_brightness_set); > + > + aat1290_brightness_set(led, led->torch_brightness); > +} > + > +static void aat1290_led_brightness_set(struct led_classdev *led_cdev, > + enum led_brightness brightness) > +{ > + struct led_classdev_flash *flash = lcdev_to_flash(led_cdev); > + struct aat1290_led *led = ldev_to_led(flash); > + > + led->torch_brightness = brightness; > + schedule_work(&led->work_brightness_set); Where is the asynchronous brightness setting used? Don't flash class devices use always the synchronous variant? > +} > + > +static int aat1290_led_brightness_set_sync(struct led_classdev *led_cdev, > + enum led_brightness brightness) > +{ > + struct led_classdev_flash *flash = lcdev_to_flash(led_cdev); > + struct aat1290_led *led = ldev_to_led(flash); > + > + aat1290_brightness_set(led, brightness); > + > + return 0; > +} > + > +static int aat1290_led_flash_strobe_set(struct led_classdev_flash *flash, > + bool state) > + > +{ > + struct aat1290_led *led = ldev_to_led(flash); > + struct led_classdev *led_cdev = &flash->led_cdev; > + struct led_flash_setting *timeout = &flash->timeout; > + > + mutex_lock(&led->lock); > + > + if (state == 0) { > + gpio_set_value(led->flen_gpio, 0); > + gpio_set_value(led->en_set_gpio, 0); > + goto unlock; > + } > + > + aat1290_set_flash_safety_timer(led, timeout->val); > + > + /* > + * To reenter movie mode after a flash event the part > + * must be cycled off and back on to reset the movie > + * mode and reprogrammed via the AS2Cwire. Therefore > + * the brightness value needs to be updated here to > + * reflect the actual state. > + */ > + led_cdev->brightness = 0; > + led->movie_mode = false; > + > + gpio_set_value(led->flen_gpio, 1); > + > +unlock: > + mutex_unlock(&led->lock); > + > + return 0; > +} > + > +static int aat1290_led_flash_timeout_set(struct led_classdev_flash *flash, > + u32 timeout) > +{ > + /* > + * Don't do anything - flash timeout is cached in the led-class-flash > + * core and will be applied in the strobe_set op, as writing the > + * safety timer register spuriously turns the torch mode on. > + */ > + > + return 0; > +} > + > +static int aat1290_led_parse_dt(struct aat1290_led *led, > + struct device *dev) > +{ > + int ret; > + char *pname = "label"; You could use two const static variables for this, or a define. No need to assign the variable in the middle. I have to admit I've usually just written the string in verbatim where I need it. :-) > + > + ret = of_property_read_string(dev->of_node, pname, > + (const char **) &led->label); > + if (ret < 0) { > + dev_err(dev, "Error reading %s Device Tree property (%d)\n", > + pname, ret); > + return ret; > + } > + > + pname = "flash-timeout-microsec"; > + > + ret = of_property_read_u32(dev->of_node, pname, &led->max_flash_tm); > + if (ret) { > + dev_err(dev, "Error reading %s Device Tree property (%d)\n", > + pname, ret); > + return ret; > + } > + > + return ret; You always return ret whether here or above. > +} > + > +static void aat1290_init_flash_settings(struct aat1290_led *led, > + struct aat1290_led_settings *s) > +{ > + struct led_flash_setting *setting; > + > + /* Init flash intensity setting */ > + setting = &s->torch_brightness; > + /* > + * Torch current is adjustable in logarithmic fashion and thus > + * it is not possible to define fixed step in microamperes. > + * Instead led brightness levels are used to make possible > + * setting all the supported levels from V4L2 Flash sub-device. > + */ > + setting->min = 1; > + setting->max = AAT1290_MAX_MM_CURR_PERCENT_0 - > + AAT1290_MAX_MM_CURR_PERCENT_100; > + setting->step = 1; > + setting->val = setting->max; > + > + /* Init flash timeout setting */ > + setting = &s->flash_timeout; > + setting->min = led->max_flash_tm / AAT1290_FLASH_TM_NUM_LEVELS; > + setting->max = setting->min * AAT1290_FLASH_TM_NUM_LEVELS; > + setting->step = setting->min; > + setting->val = setting->max; > +} > + > +static const struct led_flash_ops flash_ops = { > + .strobe_set = aat1290_led_flash_strobe_set, > + .timeout_set = aat1290_led_flash_timeout_set, > +}; > + > +static int aat1290_led_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct device_node *dev_node = pdev->dev.of_node; > + struct aat1290_led *led; > + struct led_classdev *led_cdev; > + struct led_classdev_flash *flash; > + struct aat1290_led_settings settings; > + int flen_gpio, enset_gpio, ret; > + > + led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL); > + if (!led) > + return -ENOMEM; > + > + led->pdev = pdev; > + platform_set_drvdata(pdev, led); > + > + if (!dev_node) > + return -ENXIO; > + > + flen_gpio = of_get_gpio(dev_node, 0); > + if (gpio_is_valid(flen_gpio)) { > + ret = gpio_request_one(flen_gpio, GPIOF_DIR_OUT, > + "aat1290_flen"); > + if (ret < 0) { > + dev_err(dev, > + "failed to request GPIO %d, error %d\n", > + flen_gpio, ret); > + goto error_gpio_flen; > + } > + } > + led->flen_gpio = flen_gpio; > + > + enset_gpio = of_get_gpio(dev_node, 1); > + if (gpio_is_valid(enset_gpio)) { > + ret = gpio_request_one(enset_gpio, GPIOF_DIR_OUT, Could you use devm_gpio_request_one()? > + "aat1290_en_set"); > + if (ret < 0) { > + dev_err(dev, > + "failed to request GPIO %d, error %d\n", > + enset_gpio, ret); > + goto error_gpio_en_set; > + } > + } > + led->en_set_gpio = enset_gpio; > + > + ret = aat1290_led_parse_dt(led, &pdev->dev); > + if (ret < 0) > + goto error_gpio_en_set; > + > + mutex_init(&led->lock); By moving mutex_init() up, you can avoid calling mutex_destroy() on an uninitialised mutex in error paths. > + > + flash = &led->ldev; > + > + /* Init flash settings */ > + aat1290_init_flash_settings(led, &settings); > + > + flash->timeout = settings.flash_timeout; > + > + /* Init led class */ > + led_cdev = &flash->led_cdev; > + led_cdev->name = led->label; > + led_cdev->brightness_set = aat1290_led_brightness_set; > + led_cdev->brightness_set_sync = aat1290_led_brightness_set_sync; > + led_cdev->max_brightness = settings.torch_brightness.max; > + led_cdev->flags |= LED_DEV_CAP_FLASH; > + > + INIT_WORK(&led->work_brightness_set, aat1290_brightness_set_work); > + > + flash->ops = &flash_ops; > + > + /* Register in the LED subsystem. */ > + ret = led_classdev_flash_register(&pdev->dev, flash); > + if (ret < 0) > + goto error_gpio_en_set; > + > + return 0; > + > +error_gpio_en_set: > + if (gpio_is_valid(enset_gpio)) > + gpio_free(enset_gpio); > +error_gpio_flen: > + if (gpio_is_valid(flen_gpio)) > + gpio_free(flen_gpio); > + mutex_destroy(&led->lock); > + > + return ret; > +} > + > +static int aat1290_led_remove(struct platform_device *pdev) > +{ > + struct aat1290_led *led = platform_get_drvdata(pdev); > + > + led_classdev_flash_unregister(&led->ldev); > + cancel_work_sync(&led->work_brightness_set); > + > + if (gpio_is_valid(led->en_set_gpio)) > + gpio_free(led->en_set_gpio); > + if (gpio_is_valid(led->flen_gpio)) > + gpio_free(led->flen_gpio); > + > + mutex_destroy(&led->lock); > + > + return 0; > +} > + > +static struct of_device_id aat1290_led_dt_match[] = { > + {.compatible = "skyworks,aat1290"}, > + {}, > +}; > + > +static struct platform_driver aat1290_led_driver = { > + .probe = aat1290_led_probe, > + .remove = aat1290_led_remove, > + .driver = { > + .name = "aat1290-led", > + .owner = THIS_MODULE, > + .of_match_table = aat1290_led_dt_match, > + }, > +}; > + > +module_platform_driver(aat1290_led_driver); > + > +MODULE_AUTHOR("Jacek Anaszewski "); > +MODULE_DESCRIPTION("Skyworks Current Regulator for Flash LEDs"); > +MODULE_LICENSE("GPL"); -- Kind regards, Sakari Ailus e-mail: sakari.ailus@iki.fi XMPP: sailus@retiisi.org.uk -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/