forked from Minki/linux
73f103c952
Clean up the code a bit and transition over to the gpiod based interface. Signed-off-by: Daniel Mack <daniel@zonque.org> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
148 lines
3.7 KiB
C
148 lines
3.7 KiB
C
/*
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* LEDs driver for LT3593 controllers
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*
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* See the datasheet at http://cds.linear.com/docs/Datasheet/3593f.pdf
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*
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* Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
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*
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* Based on leds-gpio.c,
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*
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* Copyright (C) 2007 8D Technologies inc.
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* Raphael Assenat <raph@8d.com>
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* Copyright (C) 2008 Freescale Semiconductor, Inc.
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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/kernel.h>
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#include <linux/platform_device.h>
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#include <linux/leds.h>
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#include <linux/delay.h>
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#include <linux/gpio.h>
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#include <linux/gpio/consumer.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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struct lt3593_led_data {
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struct led_classdev cdev;
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struct gpio_desc *gpiod;
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};
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static int lt3593_led_set(struct led_classdev *led_cdev,
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enum led_brightness value)
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{
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struct lt3593_led_data *led_dat =
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container_of(led_cdev, struct lt3593_led_data, cdev);
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int pulses;
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/*
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* The LT3593 resets its internal current level register to the maximum
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* level on the first falling edge on the control pin. Each following
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* falling edge decreases the current level by 625uA. Up to 32 pulses
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* can be sent, so the maximum power reduction is 20mA.
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* After a timeout of 128us, the value is taken from the register and
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* applied is to the output driver.
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*/
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if (value == 0) {
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gpiod_set_value_cansleep(led_dat->gpiod, 0);
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return 0;
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}
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pulses = 32 - (value * 32) / 255;
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if (pulses == 0) {
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gpiod_set_value_cansleep(led_dat->gpiod, 0);
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mdelay(1);
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gpiod_set_value_cansleep(led_dat->gpiod, 1);
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return 0;
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}
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gpiod_set_value_cansleep(led_dat->gpiod, 1);
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while (pulses--) {
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gpiod_set_value_cansleep(led_dat->gpiod, 0);
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udelay(1);
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gpiod_set_value_cansleep(led_dat->gpiod, 1);
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udelay(1);
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}
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return 0;
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}
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static struct lt3593_led_data *lt3593_led_probe_pdata(struct device *dev)
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{
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struct gpio_led_platform_data *pdata = dev_get_platdata(dev);
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const struct gpio_led *template = &pdata->leds[0];
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struct lt3593_led_data *led_data;
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int ret, state;
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if (pdata->num_leds != 1)
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return ERR_PTR(-EINVAL);
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led_data = devm_kzalloc(dev, sizeof(*led_data), GFP_KERNEL);
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if (!led_data)
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return ERR_PTR(-ENOMEM);
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led_data->cdev.name = template->name;
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led_data->cdev.default_trigger = template->default_trigger;
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led_data->cdev.brightness_set_blocking = lt3593_led_set;
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state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);
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led_data->cdev.brightness = state ? LED_FULL : LED_OFF;
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if (!template->retain_state_suspended)
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led_data->cdev.flags |= LED_CORE_SUSPENDRESUME;
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ret = devm_gpio_request_one(dev, template->gpio, state ?
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GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW,
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template->name);
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if (ret < 0)
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return ERR_PTR(ret);
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led_data->gpiod = gpio_to_desc(template->gpio);
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if (!led_data->gpiod)
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return ERR_PTR(-EPROBE_DEFER);
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ret = devm_led_classdev_register(dev, &led_data->cdev);
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if (ret < 0)
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return ERR_PTR(ret);
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dev_info(dev, "registered LT3593 LED '%s' at GPIO %d\n",
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template->name, template->gpio);
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return led_data;
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}
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static int lt3593_led_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct lt3593_led_data *led_data;
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if (dev_get_platdata(dev)) {
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led_data = lt3593_led_probe_pdata(dev);
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if (IS_ERR(led_data))
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return PTR_ERR(led_data);
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}
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platform_set_drvdata(pdev, led_data);
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return 0;
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}
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static struct platform_driver lt3593_led_driver = {
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.probe = lt3593_led_probe,
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.driver = {
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.name = "leds-lt3593",
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},
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};
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module_platform_driver(lt3593_led_driver);
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MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
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MODULE_DESCRIPTION("LED driver for LT3593 controllers");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:leds-lt3593");
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