diff options
| -rw-r--r-- | arch/sh/drivers/heartbeat.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/arch/sh/drivers/heartbeat.c b/arch/sh/drivers/heartbeat.c new file mode 100644 index 0000000..bc59cb6 --- /dev/null +++ b/arch/sh/drivers/heartbeat.c @@ -0,0 +1,132 @@ +/* + * 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> + +#define DRV_NAME "heartbeat" +#define DRV_VERSION "0.1.0" + +struct heartbeat_data { + void __iomem *base; + unsigned char bit_pos[8]; + struct timer_list timer; +}; + +static void heartbeat_timer(unsigned long data) +{ + struct heartbeat_data *hd = (struct heartbeat_data *)data; + static unsigned bit = 0, up = 1; + + ctrl_outw(1 << hd->bit_pos[bit], (unsigned long)hd->base); + if (up) + if (bit == (ARRAY_SIZE(hd->bit_pos) - 1)) { + bit--; + up = 0; + } else + bit++; + else if (bit == 0) + up = 1; + else + bit--; + + 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; + } + + hd = kmalloc(sizeof(struct heartbeat_data), GFP_KERNEL); + if (unlikely(!hd)) + return -ENOMEM; + + if (pdev->dev.platform_data) { + memcpy(hd->bit_pos, pdev->dev.platform_data, + ARRAY_SIZE(hd->bit_pos)); + } else { + int i; + + for (i = 0; i < ARRAY_SIZE(hd->bit_pos); i++) + hd->bit_pos[i] = i; + } + + hd->base = (void __iomem *)res->start; + + 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); + + platform_set_drvdata(pdev, NULL); + + 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"); |