leds: Add ktd2692 flash LED driver
This patch adds a driver to support the ktd2692 flash LEDs. ktd2692 can control flash current by ExpressWire interface. Signed-off-by: Ingi Kim <ingi2.kim@samsung.com> Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com> Reviewed-by: Varka Bhadram <varkabhadram@gmail.com> Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com> Signed-off-by: Bryan Wu <cooloney@gmail.com>
This commit is contained in:
Ingi Kim
Bryan Wu
parent
84b5def48f
commit
b7da8c5c72
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@ -532,6 +532,15 @@ config LEDS_MENF21BMC
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This driver can also be built as a module. If so the module
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will be called leds-menf21bmc.
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config LEDS_KTD2692
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tristate "LED support for KTD2692 flash LED controller"
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depends on LEDS_CLASS_FLASH && GPIOLIB && OF
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help
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This option enables support for KTD2692 LED flash connected
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through ExpressWire interface.
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Say Y to enable this driver.
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comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
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config LEDS_BLINKM
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@ -63,6 +63,7 @@ obj-$(CONFIG_LEDS_SYSCON) += leds-syscon.o
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obj-$(CONFIG_LEDS_VERSATILE) += leds-versatile.o
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obj-$(CONFIG_LEDS_MENF21BMC) += leds-menf21bmc.o
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obj-$(CONFIG_LEDS_PM8941_WLED) += leds-pm8941-wled.o
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obj-$(CONFIG_LEDS_KTD2692) += leds-ktd2692.o
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# LED SPI Drivers
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obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
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@ -0,0 +1,443 @@
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/*
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* LED driver : leds-ktd2692.c
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*
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* Copyright (C) 2015 Samsung Electronics
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* Ingi Kim <ingi2.kim@samsung.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/gpio/consumer.h>
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#include <linux/led-class-flash.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/consumer.h>
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#include <linux/workqueue.h>
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/* Value related the movie mode */
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#define KTD2692_MOVIE_MODE_CURRENT_LEVELS 16
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#define KTD2692_MM_TO_FL_RATIO(x) ((x) / 3)
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#define KTD2962_MM_MIN_CURR_THRESHOLD_SCALE 8
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/* Value related the flash mode */
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#define KTD2692_FLASH_MODE_TIMEOUT_LEVELS 8
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#define KTD2692_FLASH_MODE_TIMEOUT_DISABLE 0
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#define KTD2692_FLASH_MODE_CURR_PERCENT(x) (((x) * 16) / 100)
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/* Macro for getting offset of flash timeout */
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#define GET_TIMEOUT_OFFSET(timeout, step) ((timeout) / (step))
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/* Base register address */
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#define KTD2692_REG_LVP_BASE 0x00
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#define KTD2692_REG_FLASH_TIMEOUT_BASE 0x20
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#define KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE 0x40
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#define KTD2692_REG_MOVIE_CURRENT_BASE 0x60
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#define KTD2692_REG_FLASH_CURRENT_BASE 0x80
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#define KTD2692_REG_MODE_BASE 0xA0
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/* Set bit coding time for expresswire interface */
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#define KTD2692_TIME_RESET_US 700
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#define KTD2692_TIME_DATA_START_TIME_US 10
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#define KTD2692_TIME_HIGH_END_OF_DATA_US 350
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#define KTD2692_TIME_LOW_END_OF_DATA_US 10
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#define KTD2692_TIME_SHORT_BITSET_US 4
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#define KTD2692_TIME_LONG_BITSET_US 12
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/* KTD2692 default length of name */
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#define KTD2692_NAME_LENGTH 20
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enum ktd2692_bitset {
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KTD2692_LOW = 0,
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KTD2692_HIGH,
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};
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/* Movie / Flash Mode Control */
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enum ktd2692_led_mode {
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KTD2692_MODE_DISABLE = 0, /* default */
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KTD2692_MODE_MOVIE,
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KTD2692_MODE_FLASH,
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};
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struct ktd2692_led_config_data {
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/* maximum LED current in movie mode */
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u32 movie_max_microamp;
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/* maximum LED current in flash mode */
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u32 flash_max_microamp;
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/* maximum flash timeout */
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u32 flash_max_timeout;
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/* max LED brightness level */
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enum led_brightness max_brightness;
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};
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struct ktd2692_context {
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/* Related LED Flash class device */
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struct led_classdev_flash fled_cdev;
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/* secures access to the device */
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struct mutex lock;
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struct regulator *regulator;
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struct work_struct work_brightness_set;
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struct gpio_desc *aux_gpio;
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struct gpio_desc *ctrl_gpio;
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enum ktd2692_led_mode mode;
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enum led_brightness torch_brightness;
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};
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static struct ktd2692_context *fled_cdev_to_led(
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struct led_classdev_flash *fled_cdev)
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{
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return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
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}
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static void ktd2692_expresswire_start(struct ktd2692_context *led)
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{
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gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
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udelay(KTD2692_TIME_DATA_START_TIME_US);
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}
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static void ktd2692_expresswire_reset(struct ktd2692_context *led)
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{
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gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
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udelay(KTD2692_TIME_RESET_US);
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}
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static void ktd2692_expresswire_end(struct ktd2692_context *led)
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{
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gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
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udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
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gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
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udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
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}
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static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
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{
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/*
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* The Low Bit(0) and High Bit(1) is based on a time detection
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* algorithm between time low and time high
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* Time_(L_LB) : Low time of the Low Bit(0)
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* Time_(H_LB) : High time of the LOW Bit(0)
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* Time_(L_HB) : Low time of the High Bit(1)
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* Time_(H_HB) : High time of the High Bit(1)
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*
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* It can be simplified to:
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* Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)
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* High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)
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* HIGH ___ ____ _.. _________ ___
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* |_________| |_.. |____| |__|
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* LOW <L_LB> <H_LB> <L_HB> <H_HB>
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* [ Low Bit (0) ] [ High Bit(1) ]
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*/
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if (bit) {
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gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
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udelay(KTD2692_TIME_SHORT_BITSET_US);
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gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
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udelay(KTD2692_TIME_LONG_BITSET_US);
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} else {
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gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
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udelay(KTD2692_TIME_LONG_BITSET_US);
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gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
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udelay(KTD2692_TIME_SHORT_BITSET_US);
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}
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}
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static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
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{
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int i;
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ktd2692_expresswire_start(led);
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for (i = 7; i >= 0; i--)
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ktd2692_expresswire_set_bit(led, value & BIT(i));
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ktd2692_expresswire_end(led);
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}
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static void ktd2692_brightness_set(struct ktd2692_context *led,
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enum led_brightness brightness)
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{
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mutex_lock(&led->lock);
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if (brightness == LED_OFF) {
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led->mode = KTD2692_MODE_DISABLE;
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gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
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} else {
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ktd2692_expresswire_write(led, brightness |
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KTD2692_REG_MOVIE_CURRENT_BASE);
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led->mode = KTD2692_MODE_MOVIE;
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}
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ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
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mutex_unlock(&led->lock);
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}
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static void ktd2692_brightness_set_work(struct work_struct *work)
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{
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struct ktd2692_context *led =
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container_of(work, struct ktd2692_context, work_brightness_set);
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ktd2692_brightness_set(led, led->torch_brightness);
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}
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static void ktd2692_led_brightness_set(struct led_classdev *led_cdev,
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enum led_brightness brightness)
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{
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struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
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struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
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led->torch_brightness = brightness;
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schedule_work(&led->work_brightness_set);
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}
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static int ktd2692_led_brightness_set_sync(struct led_classdev *led_cdev,
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enum led_brightness brightness)
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{
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struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
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struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
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ktd2692_brightness_set(led, brightness);
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return 0;
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}
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static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
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bool state)
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{
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struct ktd2692_context *led = fled_cdev_to_led(fled_cdev);
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struct led_flash_setting *timeout = &fled_cdev->timeout;
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u32 flash_tm_reg;
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mutex_lock(&led->lock);
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if (state) {
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flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
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ktd2692_expresswire_write(led, flash_tm_reg
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| KTD2692_REG_FLASH_TIMEOUT_BASE);
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led->mode = KTD2692_MODE_FLASH;
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gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
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} else {
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led->mode = KTD2692_MODE_DISABLE;
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gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
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}
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ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
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fled_cdev->led_cdev.brightness = LED_OFF;
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led->mode = KTD2692_MODE_DISABLE;
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mutex_unlock(&led->lock);
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return 0;
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}
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static int ktd2692_led_flash_timeout_set(struct led_classdev_flash *fled_cdev,
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u32 timeout)
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{
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return 0;
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}
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static void ktd2692_init_movie_current_max(struct ktd2692_led_config_data *cfg)
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{
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u32 offset, step;
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u32 movie_current_microamp;
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offset = KTD2692_MOVIE_MODE_CURRENT_LEVELS;
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step = KTD2692_MM_TO_FL_RATIO(cfg->flash_max_microamp)
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/ KTD2692_MOVIE_MODE_CURRENT_LEVELS;
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do {
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movie_current_microamp = step * offset;
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offset--;
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} while ((movie_current_microamp > cfg->movie_max_microamp) &&
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(offset > 0));
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cfg->max_brightness = offset;
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}
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static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
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struct ktd2692_led_config_data *cfg)
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{
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struct led_flash_setting *setting;
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setting = &fled_cdev->timeout;
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setting->min = KTD2692_FLASH_MODE_TIMEOUT_DISABLE;
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setting->max = cfg->flash_max_timeout;
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setting->step = cfg->flash_max_timeout
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/ (KTD2692_FLASH_MODE_TIMEOUT_LEVELS - 1);
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setting->val = cfg->flash_max_timeout;
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}
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static void ktd2692_setup(struct ktd2692_context *led)
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{
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led->mode = KTD2692_MODE_DISABLE;
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ktd2692_expresswire_reset(led);
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gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
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ktd2692_expresswire_write(led, (KTD2962_MM_MIN_CURR_THRESHOLD_SCALE - 1)
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| KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
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ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
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| KTD2692_REG_FLASH_CURRENT_BASE);
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}
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static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
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struct ktd2692_led_config_data *cfg)
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{
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struct device_node *np = dev->of_node;
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struct device_node *child_node;
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int ret;
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if (!dev->of_node)
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return -ENXIO;
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led->ctrl_gpio = devm_gpiod_get(dev, "ctrl");
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if (IS_ERR(led->ctrl_gpio)) {
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ret = PTR_ERR(led->ctrl_gpio);
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dev_err(dev, "cannot get ctrl-gpios %d\n", ret);
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return ret;
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}
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led->aux_gpio = devm_gpiod_get(dev, "aux");
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if (IS_ERR(led->aux_gpio)) {
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ret = PTR_ERR(led->aux_gpio);
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dev_err(dev, "cannot get aux-gpios %d\n", ret);
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return ret;
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}
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led->regulator = devm_regulator_get(dev, "vin");
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if (IS_ERR(led->regulator))
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led->regulator = NULL;
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if (led->regulator) {
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ret = regulator_enable(led->regulator);
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if (ret)
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dev_err(dev, "Failed to enable supply: %d\n", ret);
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}
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child_node = of_get_next_available_child(np, NULL);
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if (!child_node) {
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dev_err(dev, "No DT child node found for connected LED.\n");
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return -EINVAL;
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}
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led->fled_cdev.led_cdev.name =
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of_get_property(child_node, "label", NULL) ? : child_node->name;
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ret = of_property_read_u32(child_node, "led-max-microamp",
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&cfg->movie_max_microamp);
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if (ret) {
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dev_err(dev, "failed to parse led-max-microamp\n");
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return ret;
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}
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ret = of_property_read_u32(child_node, "flash-max-microamp",
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&cfg->flash_max_microamp);
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if (ret) {
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dev_err(dev, "failed to parse flash-max-microamp\n");
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return ret;
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}
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ret = of_property_read_u32(child_node, "flash-max-timeout-us",
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&cfg->flash_max_timeout);
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if (ret)
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dev_err(dev, "failed to parse flash-max-timeout-us\n");
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of_node_put(child_node);
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return ret;
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}
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static const struct led_flash_ops flash_ops = {
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.strobe_set = ktd2692_led_flash_strobe_set,
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.timeout_set = ktd2692_led_flash_timeout_set,
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};
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static int ktd2692_probe(struct platform_device *pdev)
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{
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struct ktd2692_context *led;
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struct led_classdev *led_cdev;
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struct led_classdev_flash *fled_cdev;
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struct ktd2692_led_config_data led_cfg;
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int ret;
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led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
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if (!led)
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return -ENOMEM;
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fled_cdev = &led->fled_cdev;
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led_cdev = &fled_cdev->led_cdev;
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ret = ktd2692_parse_dt(led, &pdev->dev, &led_cfg);
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if (ret)
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return ret;
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ktd2692_init_flash_timeout(fled_cdev, &led_cfg);
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ktd2692_init_movie_current_max(&led_cfg);
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fled_cdev->ops = &flash_ops;
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led_cdev->max_brightness = led_cfg.max_brightness;
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led_cdev->brightness_set = ktd2692_led_brightness_set;
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led_cdev->brightness_set_sync = ktd2692_led_brightness_set_sync;
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led_cdev->flags |= LED_CORE_SUSPENDRESUME | LED_DEV_CAP_FLASH;
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mutex_init(&led->lock);
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INIT_WORK(&led->work_brightness_set, ktd2692_brightness_set_work);
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platform_set_drvdata(pdev, led);
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ret = led_classdev_flash_register(&pdev->dev, fled_cdev);
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if (ret) {
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dev_err(&pdev->dev, "can't register LED %s\n", led_cdev->name);
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mutex_destroy(&led->lock);
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return ret;
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}
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ktd2692_setup(led);
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return 0;
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||||
}
|
||||
|
||||
static int ktd2692_remove(struct platform_device *pdev)
|
||||
{
|
||||
struct ktd2692_context *led = platform_get_drvdata(pdev);
|
||||
int ret;
|
||||
|
||||
led_classdev_flash_unregister(&led->fled_cdev);
|
||||
cancel_work_sync(&led->work_brightness_set);
|
||||
|
||||
if (led->regulator) {
|
||||
ret = regulator_disable(led->regulator);
|
||||
if (ret)
|
||||
dev_err(&pdev->dev,
|
||||
"Failed to disable supply: %d\n", ret);
|
||||
}
|
||||
|
||||
mutex_destroy(&led->lock);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct of_device_id ktd2692_match[] = {
|
||||
{ .compatible = "kinetic,ktd2692", },
|
||||
{ /* sentinel */ },
|
||||
};
|
||||
|
||||
static struct platform_driver ktd2692_driver = {
|
||||
.driver = {
|
||||
.name = "ktd2692",
|
||||
.of_match_table = ktd2692_match,
|
||||
},
|
||||
.probe = ktd2692_probe,
|
||||
.remove = ktd2692_remove,
|
||||
};
|
||||
|
||||
module_platform_driver(ktd2692_driver);
|
||||
|
||||
MODULE_AUTHOR("Ingi Kim <ingi2.kim@samsung.com>");
|
||||
MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
Loading…
Reference in New Issue