... and we have few enough places using the latter to make it simpler to do search and replace... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			157 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			157 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Generic heartbeat driver for regular LED banks
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 *
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 * Copyright (C) 2007  Paul Mundt
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 *
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 * Most SH reference boards include a number of individual LEDs that can
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 * be independently controlled (either via a pre-defined hardware
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 * function or via the LED class, if desired -- the hardware tends to
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 * encapsulate some of the same "triggers" that the LED class supports,
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 * so there's not too much value in it).
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 *
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 * Additionally, most of these boards also have a LED bank that we've
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 * traditionally used for strobing the load average. This use case is
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 * handled by this driver, rather than giving each LED bit position its
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 * own struct device.
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 *
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 * This file is subject to the terms and conditions of the GNU General Public
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 * License.  See the file "COPYING" in the main directory of this archive
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 * for more details.
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 */
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/sched.h>
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#include <linux/timer.h>
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#include <linux/io.h>
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#include <asm/heartbeat.h>
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#define DRV_NAME "heartbeat"
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#define DRV_VERSION "0.1.1"
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static unsigned char default_bit_pos[] = { 0, 1, 2, 3, 4, 5, 6, 7 };
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static inline void heartbeat_toggle_bit(struct heartbeat_data *hd,
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					unsigned bit, unsigned int inverted)
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{
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	unsigned int new;
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	new = (1 << hd->bit_pos[bit]);
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	if (inverted)
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		new = ~new;
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	switch (hd->regsize) {
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	case 32:
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		iowrite32(new, hd->base);
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		break;
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	case 16:
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		iowrite16(new, hd->base);
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		break;
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	default:
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		iowrite8(new, hd->base);
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		break;
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	}
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}
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static void heartbeat_timer(unsigned long data)
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{
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	struct heartbeat_data *hd = (struct heartbeat_data *)data;
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	static unsigned bit = 0, up = 1;
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	heartbeat_toggle_bit(hd, bit, hd->flags & HEARTBEAT_INVERTED);
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	bit += up;
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	if ((bit == 0) || (bit == (hd->nr_bits)-1))
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		up = -up;
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	mod_timer(&hd->timer, jiffies + (110 - ((300 << FSHIFT) /
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			((avenrun[0] / 5) + (3 << FSHIFT)))));
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}
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static int heartbeat_drv_probe(struct platform_device *pdev)
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{
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	struct resource *res;
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	struct heartbeat_data *hd;
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	if (unlikely(pdev->num_resources != 1)) {
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		dev_err(&pdev->dev, "invalid number of resources\n");
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		return -EINVAL;
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	}
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	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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	if (unlikely(res == NULL)) {
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		dev_err(&pdev->dev, "invalid resource\n");
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		return -EINVAL;
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	}
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	if (pdev->dev.platform_data) {
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		hd = pdev->dev.platform_data;
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	} else {
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		hd = kzalloc(sizeof(struct heartbeat_data), GFP_KERNEL);
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		if (unlikely(!hd))
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			return -ENOMEM;
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	}
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	hd->base = ioremap_nocache(res->start, res->end - res->start + 1);
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	if (unlikely(!hd->base)) {
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		dev_err(&pdev->dev, "ioremap failed\n");
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		if (!pdev->dev.platform_data)
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			kfree(hd);
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		return -ENXIO;
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	}
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	if (!hd->nr_bits) {
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		hd->bit_pos = default_bit_pos;
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		hd->nr_bits = ARRAY_SIZE(default_bit_pos);
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	}
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	if (!hd->regsize)
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		hd->regsize = 8;	/* default access size */
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	setup_timer(&hd->timer, heartbeat_timer, (unsigned long)hd);
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	platform_set_drvdata(pdev, hd);
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	return mod_timer(&hd->timer, jiffies + 1);
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}
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static int heartbeat_drv_remove(struct platform_device *pdev)
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{
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	struct heartbeat_data *hd = platform_get_drvdata(pdev);
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	del_timer_sync(&hd->timer);
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	iounmap(hd->base);
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	platform_set_drvdata(pdev, NULL);
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	if (!pdev->dev.platform_data)
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		kfree(hd);
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	return 0;
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}
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static struct platform_driver heartbeat_driver = {
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	.probe		= heartbeat_drv_probe,
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	.remove		= heartbeat_drv_remove,
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	.driver		= {
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		.name	= DRV_NAME,
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	},
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};
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static int __init heartbeat_init(void)
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{
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	printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);
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	return platform_driver_register(&heartbeat_driver);
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}
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static void __exit heartbeat_exit(void)
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{
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	platform_driver_unregister(&heartbeat_driver);
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}
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module_init(heartbeat_init);
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module_exit(heartbeat_exit);
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MODULE_VERSION(DRV_VERSION);
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MODULE_AUTHOR("Paul Mundt");
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MODULE_LICENSE("GPL v2");
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