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7534904d42
The struct containing the KTD2801 timing can be made static as it's not referenced outside the KTD2801 driver. Do this to prevent sparse complaints. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202402100625.M0RkJhMh-lkp@intel.com/ Signed-off-by: Duje Mihanović <duje.mihanovic@skole.hr> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Link: https://lore.kernel.org/r/20240210-ktd2801-static-v1-1-90ad2e2e8483@skole.hr Signed-off-by: Lee Jones <lee@kernel.org>
129 lines
3.4 KiB
C
129 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Datasheet:
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* https://www.kinet-ic.com/uploads/web/KTD2801/KTD2801-04b.pdf
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*/
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#include <linux/backlight.h>
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#include <linux/gpio/consumer.h>
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#include <linux/leds-expresswire.h>
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#include <linux/platform_device.h>
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#include <linux/property.h>
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#define KTD2801_DEFAULT_BRIGHTNESS 100
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#define KTD2801_MAX_BRIGHTNESS 255
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/* These values have been extracted from Samsung's driver. */
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static const struct expresswire_timing ktd2801_timing = {
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.poweroff_us = 2600,
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.detect_delay_us = 150,
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.detect_us = 270,
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.data_start_us = 5,
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.short_bitset_us = 5,
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.long_bitset_us = 15,
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.end_of_data_low_us = 10,
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.end_of_data_high_us = 350
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};
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struct ktd2801_backlight {
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struct expresswire_common_props props;
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struct backlight_device *bd;
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bool was_on;
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};
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static int ktd2801_update_status(struct backlight_device *bd)
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{
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struct ktd2801_backlight *ktd2801 = bl_get_data(bd);
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u8 brightness = (u8) backlight_get_brightness(bd);
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if (backlight_is_blank(bd)) {
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expresswire_power_off(&ktd2801->props);
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ktd2801->was_on = false;
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return 0;
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}
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if (!ktd2801->was_on) {
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expresswire_enable(&ktd2801->props);
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ktd2801->was_on = true;
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}
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expresswire_write_u8(&ktd2801->props, brightness);
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return 0;
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}
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static const struct backlight_ops ktd2801_backlight_ops = {
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.update_status = ktd2801_update_status,
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};
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static int ktd2801_backlight_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct backlight_device *bd;
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struct ktd2801_backlight *ktd2801;
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u32 brightness, max_brightness;
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int ret;
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ktd2801 = devm_kzalloc(dev, sizeof(*ktd2801), GFP_KERNEL);
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if (!ktd2801)
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return -ENOMEM;
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ktd2801->was_on = true;
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ktd2801->props.timing = ktd2801_timing;
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ret = device_property_read_u32(dev, "max-brightness", &max_brightness);
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if (ret)
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max_brightness = KTD2801_MAX_BRIGHTNESS;
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if (max_brightness > KTD2801_MAX_BRIGHTNESS) {
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dev_err(dev, "illegal max brightness specified\n");
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max_brightness = KTD2801_MAX_BRIGHTNESS;
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}
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ret = device_property_read_u32(dev, "default-brightness", &brightness);
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if (ret)
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brightness = KTD2801_DEFAULT_BRIGHTNESS;
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if (brightness > max_brightness) {
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dev_err(dev, "default brightness exceeds max\n");
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brightness = max_brightness;
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}
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ktd2801->props.ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_OUT_HIGH);
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if (IS_ERR(ktd2801->props.ctrl_gpio))
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return dev_err_probe(dev, PTR_ERR(ktd2801->props.ctrl_gpio),
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"failed to get backlight GPIO");
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gpiod_set_consumer_name(ktd2801->props.ctrl_gpio, dev_name(dev));
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bd = devm_backlight_device_register(dev, dev_name(dev), dev, ktd2801,
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&ktd2801_backlight_ops, NULL);
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if (IS_ERR(bd))
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return dev_err_probe(dev, PTR_ERR(bd),
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"failed to register backlight");
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bd->props.max_brightness = max_brightness;
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bd->props.brightness = brightness;
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ktd2801->bd = bd;
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platform_set_drvdata(pdev, bd);
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backlight_update_status(bd);
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return 0;
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}
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static const struct of_device_id ktd2801_of_match[] = {
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{ .compatible = "kinetic,ktd2801" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, ktd2801_of_match);
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static struct platform_driver ktd2801_backlight_driver = {
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.driver = {
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.name = "ktd2801-backlight",
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.of_match_table = ktd2801_of_match,
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},
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.probe = ktd2801_backlight_probe,
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};
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module_platform_driver(ktd2801_backlight_driver);
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MODULE_IMPORT_NS(EXPRESSWIRE);
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MODULE_AUTHOR("Duje Mihanović <duje.mihanovic@skole.hr>");
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MODULE_DESCRIPTION("Kinetic KTD2801 Backlight Driver");
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MODULE_LICENSE("GPL");
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