82 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			82 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| /*
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|  *
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|  * iPAQ microcontroller backlight support
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|  * Author : Linus Walleij <linus.walleij@linaro.org>
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|  */
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| 
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| #include <linux/backlight.h>
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| #include <linux/err.h>
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| #include <linux/fb.h>
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| #include <linux/init.h>
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| #include <linux/mfd/ipaq-micro.h>
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| #include <linux/module.h>
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| #include <linux/platform_device.h>
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| 
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| static int micro_bl_update_status(struct backlight_device *bd)
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| {
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| 	struct ipaq_micro *micro = dev_get_drvdata(&bd->dev);
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| 	int intensity = bd->props.brightness;
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| 	struct ipaq_micro_msg msg = {
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| 		.id = MSG_BACKLIGHT,
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| 		.tx_len = 3,
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| 	};
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| 
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| 	if (bd->props.power != FB_BLANK_UNBLANK)
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| 		intensity = 0;
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| 	if (bd->props.state & (BL_CORE_FBBLANK | BL_CORE_SUSPENDED))
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| 		intensity = 0;
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| 
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| 	/*
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| 	 * Message format:
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| 	 * Byte 0: backlight instance (usually 1)
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| 	 * Byte 1: on/off
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| 	 * Byte 2: intensity, 0-255
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| 	 */
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| 	msg.tx_data[0] = 0x01;
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| 	msg.tx_data[1] = intensity > 0 ? 1 : 0;
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| 	msg.tx_data[2] = intensity;
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| 	return ipaq_micro_tx_msg_sync(micro, &msg);
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| }
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| 
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| static const struct backlight_ops micro_bl_ops = {
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| 	.options = BL_CORE_SUSPENDRESUME,
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| 	.update_status  = micro_bl_update_status,
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| };
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| 
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| static const struct backlight_properties micro_bl_props = {
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| 	.type = BACKLIGHT_RAW,
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| 	.max_brightness = 255,
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| 	.power = FB_BLANK_UNBLANK,
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| 	.brightness = 64,
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| };
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| 
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| static int micro_backlight_probe(struct platform_device *pdev)
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| {
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| 	struct backlight_device *bd;
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| 	struct ipaq_micro *micro = dev_get_drvdata(pdev->dev.parent);
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| 
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| 	bd = devm_backlight_device_register(&pdev->dev, "ipaq-micro-backlight",
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| 					    &pdev->dev, micro, µ_bl_ops,
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| 					    µ_bl_props);
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| 	if (IS_ERR(bd))
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| 		return PTR_ERR(bd);
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| 
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| 	platform_set_drvdata(pdev, bd);
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| 	backlight_update_status(bd);
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| 
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| 	return 0;
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| }
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| 
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| static struct platform_driver micro_backlight_device_driver = {
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| 	.driver = {
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| 		.name    = "ipaq-micro-backlight",
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| 	},
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| 	.probe   = micro_backlight_probe,
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| };
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| module_platform_driver(micro_backlight_device_driver);
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| 
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| MODULE_LICENSE("GPL v2");
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| MODULE_DESCRIPTION("driver for iPAQ Atmel micro backlight");
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| MODULE_ALIAS("platform:ipaq-micro-backlight");
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