forked from Minki/linux
d8be286739
In preparation to DT probe functionality, merge create_lt3593_led() into its only call-site. The DT based setup code will be quite different, so this internal helper function is of no help. This also changes the way the driver works by only handling one entry inside 'struct gpio_led_platform_data'. If multiple devices of the same type are found in a design, there should be a platform device for each of them. The only mainline user of this driver is not affected by this change. Last, use devm_led_classdev_register() instead of led_classdev_register(), so the driver's remove callback can go away. Signed-off-by: Daniel Mack <daniel@zonque.org> Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
150 lines
3.8 KiB
C
150 lines
3.8 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/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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unsigned gpio;
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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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gpio_set_value_cansleep(led_dat->gpio, 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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gpio_set_value_cansleep(led_dat->gpio, 0);
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mdelay(1);
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gpio_set_value_cansleep(led_dat->gpio, 1);
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return 0;
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}
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gpio_set_value_cansleep(led_dat->gpio, 1);
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while (pulses--) {
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gpio_set_value_cansleep(led_dat->gpio, 0);
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udelay(1);
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gpio_set_value_cansleep(led_dat->gpio, 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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if (!gpio_is_valid(template->gpio)) {
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dev_info(dev, "skipping unavailable LT3593 LED at gpio "
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"%d (%s)\n", template->gpio, template->name);
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return ERR_PTR(-EINVAL);
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}
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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->gpio = template->gpio;
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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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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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