From 7aea8389a77abf9fde254aca2434a605c7704f58 Mon Sep 17 00:00:00 2001 From: Jacek Anaszewski Date: Fri, 9 Jan 2015 07:22:51 -0800 Subject: leds: Add LED Flash class extension to the LED subsystem Some LED devices support two operation modes - torch and flash. This patch provides support for flash LED devices in the LED subsystem by introducing new sysfs attributes and kernel internal interface. The attributes being introduced are: flash_brightness, flash_strobe, flash_timeout, max_flash_timeout, max_flash_brightness, flash_fault, flash_sync_strobe and available_sync_leds. All the flash related features are placed in a separate module. The modifications aim to be compatible with V4L2 framework requirements related to the flash devices management. The design assumes that V4L2 sub-device can take of the LED class device control and communicate with it through the kernel internal interface. When V4L2 Flash sub-device file is opened, the LED class device sysfs interface is made unavailable. Signed-off-by: Jacek Anaszewski Acked-by: Kyungmin Park Cc: Richard Purdie Acked-by: Pavel Machek Signed-off-by: Bryan Wu --- drivers/leds/led-class-flash.c | 486 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 486 insertions(+) create mode 100644 drivers/leds/led-class-flash.c (limited to 'drivers/leds/led-class-flash.c') diff --git a/drivers/leds/led-class-flash.c b/drivers/leds/led-class-flash.c new file mode 100644 index 0000000..4a19fd4 --- /dev/null +++ b/drivers/leds/led-class-flash.c @@ -0,0 +1,486 @@ +/* + * LED Flash class interface + * + * Copyright (C) 2015 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 "leds.h" + +#define has_flash_op(fled_cdev, op) \ + (fled_cdev && fled_cdev->ops->op) + +#define call_flash_op(fled_cdev, op, args...) \ + ((has_flash_op(fled_cdev, op)) ? \ + (fled_cdev->ops->op(fled_cdev, args)) : \ + -EINVAL) + +static const char * const led_flash_fault_names[] = { + "led-over-voltage", + "flash-timeout-exceeded", + "controller-over-temperature", + "controller-short-circuit", + "led-power-supply-over-current", + "indicator-led-fault", + "led-under-voltage", + "controller-under-voltage", + "led-over-temperature", +}; + +static ssize_t flash_brightness_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + unsigned long state; + ssize_t ret; + + mutex_lock(&led_cdev->led_access); + + if (led_sysfs_is_disabled(led_cdev)) { + ret = -EBUSY; + goto unlock; + } + + ret = kstrtoul(buf, 10, &state); + if (ret) + goto unlock; + + ret = led_set_flash_brightness(fled_cdev, state); + if (ret < 0) + goto unlock; + + ret = size; +unlock: + mutex_unlock(&led_cdev->led_access); + return ret; +} + +static ssize_t flash_brightness_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + + /* no lock needed for this */ + led_update_flash_brightness(fled_cdev); + + return sprintf(buf, "%u\n", fled_cdev->brightness.val); +} +static DEVICE_ATTR_RW(flash_brightness); + +static ssize_t max_flash_brightness_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + + return sprintf(buf, "%u\n", fled_cdev->brightness.max); +} +static DEVICE_ATTR_RO(max_flash_brightness); + +static ssize_t flash_strobe_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + unsigned long state; + ssize_t ret = -EINVAL; + + mutex_lock(&led_cdev->led_access); + + if (led_sysfs_is_disabled(led_cdev)) { + ret = -EBUSY; + goto unlock; + } + + ret = kstrtoul(buf, 10, &state); + if (ret) + goto unlock; + + if (state < 0 || state > 1) { + ret = -EINVAL; + goto unlock; + } + + ret = led_set_flash_strobe(fled_cdev, state); + if (ret < 0) + goto unlock; + ret = size; +unlock: + mutex_unlock(&led_cdev->led_access); + return ret; +} + +static ssize_t flash_strobe_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + bool state; + int ret; + + /* no lock needed for this */ + ret = led_get_flash_strobe(fled_cdev, &state); + if (ret < 0) + return ret; + + return sprintf(buf, "%u\n", state); +} +static DEVICE_ATTR_RW(flash_strobe); + +static ssize_t flash_timeout_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + unsigned long flash_timeout; + ssize_t ret; + + mutex_lock(&led_cdev->led_access); + + if (led_sysfs_is_disabled(led_cdev)) { + ret = -EBUSY; + goto unlock; + } + + ret = kstrtoul(buf, 10, &flash_timeout); + if (ret) + goto unlock; + + ret = led_set_flash_timeout(fled_cdev, flash_timeout); + if (ret < 0) + goto unlock; + + ret = size; +unlock: + mutex_unlock(&led_cdev->led_access); + return ret; +} + +static ssize_t flash_timeout_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + + return sprintf(buf, "%u\n", fled_cdev->timeout.val); +} +static DEVICE_ATTR_RW(flash_timeout); + +static ssize_t max_flash_timeout_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + + return sprintf(buf, "%u\n", fled_cdev->timeout.max); +} +static DEVICE_ATTR_RO(max_flash_timeout); + +static ssize_t flash_fault_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + u32 fault, mask = 0x1; + char *pbuf = buf; + int i, ret, buf_len; + + ret = led_get_flash_fault(fled_cdev, &fault); + if (ret < 0) + return -EINVAL; + + *buf = '\0'; + + for (i = 0; i < LED_NUM_FLASH_FAULTS; ++i) { + if (fault & mask) { + buf_len = sprintf(pbuf, "%s ", + led_flash_fault_names[i]); + pbuf += buf_len; + } + mask <<= 1; + } + + return sprintf(buf, "%s\n", buf); +} +static DEVICE_ATTR_RO(flash_fault); + +static ssize_t available_sync_leds_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + char *pbuf = buf; + int i, buf_len; + + buf_len = sprintf(pbuf, "[0: none] "); + pbuf += buf_len; + + for (i = 0; i < fled_cdev->num_sync_leds; ++i) { + buf_len = sprintf(pbuf, "[%d: %s] ", i + 1, + fled_cdev->sync_leds[i]->led_cdev.name); + pbuf += buf_len; + } + + return sprintf(buf, "%s\n", buf); +} +static DEVICE_ATTR_RO(available_sync_leds); + +static ssize_t flash_sync_strobe_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + unsigned long led_id; + ssize_t ret; + + mutex_lock(&led_cdev->led_access); + + if (led_sysfs_is_disabled(led_cdev)) { + ret = -EBUSY; + goto unlock; + } + + ret = kstrtoul(buf, 10, &led_id); + if (ret) + goto unlock; + + if (led_id > fled_cdev->num_sync_leds) { + ret = -ERANGE; + goto unlock; + } + + fled_cdev->sync_led_id = led_id; + + ret = size; +unlock: + mutex_unlock(&led_cdev->led_access); + return ret; +} + +static ssize_t flash_sync_strobe_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + int sled_id = fled_cdev->sync_led_id; + char *sync_led_name = "none"; + + if (fled_cdev->sync_led_id > 0) + sync_led_name = (char *) + fled_cdev->sync_leds[sled_id - 1]->led_cdev.name; + + return sprintf(buf, "[%d: %s]\n", sled_id, sync_led_name); +} +static DEVICE_ATTR_RW(flash_sync_strobe); + +static struct attribute *led_flash_strobe_attrs[] = { + &dev_attr_flash_strobe.attr, + NULL, +}; + +static struct attribute *led_flash_timeout_attrs[] = { + &dev_attr_flash_timeout.attr, + &dev_attr_max_flash_timeout.attr, + NULL, +}; + +static struct attribute *led_flash_brightness_attrs[] = { + &dev_attr_flash_brightness.attr, + &dev_attr_max_flash_brightness.attr, + NULL, +}; + +static struct attribute *led_flash_fault_attrs[] = { + &dev_attr_flash_fault.attr, + NULL, +}; + +static struct attribute *led_flash_sync_strobe_attrs[] = { + &dev_attr_available_sync_leds.attr, + &dev_attr_flash_sync_strobe.attr, + NULL, +}; + +static const struct attribute_group led_flash_strobe_group = { + .attrs = led_flash_strobe_attrs, +}; + +static const struct attribute_group led_flash_timeout_group = { + .attrs = led_flash_timeout_attrs, +}; + +static const struct attribute_group led_flash_brightness_group = { + .attrs = led_flash_brightness_attrs, +}; + +static const struct attribute_group led_flash_fault_group = { + .attrs = led_flash_fault_attrs, +}; + +static const struct attribute_group led_flash_sync_strobe_group = { + .attrs = led_flash_sync_strobe_attrs, +}; + +static void led_flash_resume(struct led_classdev *led_cdev) +{ + struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev); + + call_flash_op(fled_cdev, flash_brightness_set, + fled_cdev->brightness.val); + call_flash_op(fled_cdev, timeout_set, fled_cdev->timeout.val); +} + +static void led_flash_init_sysfs_groups(struct led_classdev_flash *fled_cdev) +{ + struct led_classdev *led_cdev = &fled_cdev->led_cdev; + const struct led_flash_ops *ops = fled_cdev->ops; + const struct attribute_group **flash_groups = fled_cdev->sysfs_groups; + + int num_sysfs_groups = 0; + + flash_groups[num_sysfs_groups++] = &led_flash_strobe_group; + + if (ops->flash_brightness_set) + flash_groups[num_sysfs_groups++] = &led_flash_brightness_group; + + if (ops->timeout_set) + flash_groups[num_sysfs_groups++] = &led_flash_timeout_group; + + if (ops->fault_get) + flash_groups[num_sysfs_groups++] = &led_flash_fault_group; + + if (led_cdev->flags & LED_DEV_CAP_SYNC_STROBE) + flash_groups[num_sysfs_groups++] = &led_flash_sync_strobe_group; + + led_cdev->groups = flash_groups; +} + +int led_classdev_flash_register(struct device *parent, + struct led_classdev_flash *fled_cdev) +{ + struct led_classdev *led_cdev; + const struct led_flash_ops *ops; + int ret; + + if (!fled_cdev) + return -EINVAL; + + led_cdev = &fled_cdev->led_cdev; + + if (led_cdev->flags & LED_DEV_CAP_FLASH) { + if (!led_cdev->brightness_set_sync) + return -EINVAL; + + ops = fled_cdev->ops; + if (!ops || !ops->strobe_set) + return -EINVAL; + + led_cdev->flash_resume = led_flash_resume; + + /* Select the sysfs attributes to be created for the device */ + led_flash_init_sysfs_groups(fled_cdev); + } + + /* Register led class device */ + ret = led_classdev_register(parent, led_cdev); + if (ret < 0) + return ret; + + /* Setting a torch brightness needs to have immediate effect */ + led_cdev->flags &= ~SET_BRIGHTNESS_ASYNC; + led_cdev->flags |= SET_BRIGHTNESS_SYNC; + + return 0; +} +EXPORT_SYMBOL_GPL(led_classdev_flash_register); + +void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev) +{ + if (!fled_cdev) + return; + + led_classdev_unregister(&fled_cdev->led_cdev); +} +EXPORT_SYMBOL_GPL(led_classdev_flash_unregister); + +static void led_clamp_align(struct led_flash_setting *s) +{ + u32 v, offset; + + v = s->val + s->step / 2; + v = clamp(v, s->min, s->max); + offset = v - s->min; + offset = s->step * (offset / s->step); + s->val = s->min + offset; +} + +int led_set_flash_timeout(struct led_classdev_flash *fled_cdev, u32 timeout) +{ + struct led_classdev *led_cdev = &fled_cdev->led_cdev; + struct led_flash_setting *s = &fled_cdev->timeout; + + s->val = timeout; + led_clamp_align(s); + + if (!(led_cdev->flags & LED_SUSPENDED)) + return call_flash_op(fled_cdev, timeout_set, s->val); + + return 0; +} +EXPORT_SYMBOL_GPL(led_set_flash_timeout); + +int led_get_flash_fault(struct led_classdev_flash *fled_cdev, u32 *fault) +{ + return call_flash_op(fled_cdev, fault_get, fault); +} +EXPORT_SYMBOL_GPL(led_get_flash_fault); + +int led_set_flash_brightness(struct led_classdev_flash *fled_cdev, + u32 brightness) +{ + struct led_classdev *led_cdev = &fled_cdev->led_cdev; + struct led_flash_setting *s = &fled_cdev->brightness; + + s->val = brightness; + led_clamp_align(s); + + if (!(led_cdev->flags & LED_SUSPENDED)) + return call_flash_op(fled_cdev, flash_brightness_set, s->val); + + return 0; +} +EXPORT_SYMBOL_GPL(led_set_flash_brightness); + +int led_update_flash_brightness(struct led_classdev_flash *fled_cdev) +{ + struct led_flash_setting *s = &fled_cdev->brightness; + u32 brightness; + + if (has_flash_op(fled_cdev, flash_brightness_get)) { + int ret = call_flash_op(fled_cdev, flash_brightness_get, + &brightness); + if (ret < 0) + return ret; + + s->val = brightness; + } + + return 0; +} +EXPORT_SYMBOL_GPL(led_update_flash_brightness); + +MODULE_AUTHOR("Jacek Anaszewski "); +MODULE_DESCRIPTION("LED Flash class interface"); +MODULE_LICENSE("GPL v2"); -- cgit v1.1