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 <j.anaszewski@xxxxxxxxxxx>
> Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> Cc: Bryan Wu <cooloney@xxxxxxxxx>
> Cc: Richard Purdie <rpurdie@xxxxxxxxx>
> ---
> 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 <j.anaszewski@xxxxxxxxxxx>
> + *
> + * 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 <linux/delay.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/led-class-flash.h>
> +#include <linux/leds.h>
> +#include <linux/mutex.h>
> +#include <linux/gpio.h>
> +#include <linux/of_gpio.h>
> +#include <linux/of.h>
> +#include <linux/workqueue.h>
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 <j.anaszewski@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Skyworks Current Regulator for Flash LEDs");
> +MODULE_LICENSE("GPL");
--
Kind regards,
Sakari Ailus
e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx
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