Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * Generic heartbeat driver for regular LED banks

 *

 * Copyright (C) 2007  Paul Mundt

 *

 * Most SH reference boards include a number of individual LEDs that can

 * be independently controlled (either via a pre-defined hardware

 * function or via the LED class, if desired -- the hardware tends to

 * encapsulate some of the same "triggers" that the LED class supports,

 * so there's not too much value in it).

 *

 * Additionally, most of these boards also have a LED bank that we've

 * traditionally used for strobing the load average. This use case is

 * handled by this driver, rather than giving each LED bit position its

 * own struct device.

 *

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 */

#include <linux/init.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/sched.h>

#include <linux/timer.h>

#include <linux/io.h>

#include <asm/heartbeat.h>

#define DRV_NAME "heartbeat"

#define DRV_VERSION "0.1.1"

static unsigned char default_bit_pos[] = { 0, 1, 2, 3, 4, 5, 6, 7 };

static inline void heartbeat_toggle_bit(struct heartbeat_data *hd,

                                        unsigned bit, unsigned int inverted)

{

        unsigned int new;

        new = (1 << hd->bit_pos[bit]);

        if (inverted)

                new = ~new;

        switch (hd->regsize) {

        case 32:

                iowrite32(new, hd->base);

                break;

        case 16:

                iowrite16(new, hd->base);

                break;

        default:

                iowrite8(new, hd->base);

                break;

        }

}

static void heartbeat_timer(unsigned long data)

{

        struct heartbeat_data *hd = (struct heartbeat_data *)data;

        static unsigned bit = 0, up = 1;

        heartbeat_toggle_bit(hd, bit, hd->flags & HEARTBEAT_INVERTED);

        bit += up;

        if ((bit == 0) || (bit == (hd->nr_bits)-1))

                up = -up;

        mod_timer(&hd->timer, jiffies + (110 - ((300 << FSHIFT) /

                        ((avenrun[0] / 5) + (3 << FSHIFT)))));

}

static int heartbeat_drv_probe(struct platform_device *pdev)

{

        struct resource *res;

        struct heartbeat_data *hd;

        if (unlikely(pdev->num_resources != 1)) {

                dev_err(&pdev->dev, "invalid number of resources\n");

                return -EINVAL;

        }

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

        if (unlikely(res == NULL)) {

                dev_err(&pdev->dev, "invalid resource\n");

                return -EINVAL;

        }

        if (pdev->dev.platform_data) {

                hd = pdev->dev.platform_data;

        } else {

                hd = kzalloc(sizeof(struct heartbeat_data), GFP_KERNEL);

                if (unlikely(!hd))

                        return -ENOMEM;

        }

        hd->base = ioremap_nocache(res->start, res->end - res->start + 1);

        if (!unlikely(hd->base)) {

                dev_err(&pdev->dev, "ioremap failed\n");

                if (!pdev->dev.platform_data)

                        kfree(hd);

                return -ENXIO;

        }

        if (!hd->nr_bits) {

                hd->bit_pos = default_bit_pos;

                hd->nr_bits = ARRAY_SIZE(default_bit_pos);

        }

        if (!hd->regsize)

                hd->regsize = 8;        /* default access size */

        setup_timer(&hd->timer, heartbeat_timer, (unsigned long)hd);

        platform_set_drvdata(pdev, hd);

        return mod_timer(&hd->timer, jiffies + 1);

}

static int heartbeat_drv_remove(struct platform_device *pdev)

{

        struct heartbeat_data *hd = platform_get_drvdata(pdev);

        del_timer_sync(&hd->timer);

        iounmap(hd->base);

        platform_set_drvdata(pdev, NULL);

        if (!pdev->dev.platform_data)

                kfree(hd);

        return 0;

}

static struct platform_driver heartbeat_driver = {

        .probe          = heartbeat_drv_probe,

        .remove         = heartbeat_drv_remove,

        .driver         = {

                .name   = DRV_NAME,

        },

};

static int __init heartbeat_init(void)

{

        printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION);

        return platform_driver_register(&heartbeat_driver);

}

static void __exit heartbeat_exit(void)

{

        platform_driver_unregister(&heartbeat_driver);

}

module_init(heartbeat_init);

module_exit(heartbeat_exit);

MODULE_VERSION(DRV_VERSION);

MODULE_AUTHOR("Paul Mundt");

MODULE_LICENSE("GPLv2");