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8786c952c1
Add some flags for the heartbeat driver, and kill off some duplication in the bit positions for the boards that don't have special cases. This also allows for variable access widths and inversion. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
158 lines
3.7 KiB
C
158 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("GPLv2");
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