Paul Mundt | 401e909 | 2007-02-13 15:46:39 +0900 | [diff] [blame] | 1 | /* |
| 2 | * Generic heartbeat driver for regular LED banks |
| 3 | * |
| 4 | * Copyright (C) 2007 Paul Mundt |
| 5 | * |
| 6 | * Most SH reference boards include a number of individual LEDs that can |
| 7 | * be independently controlled (either via a pre-defined hardware |
| 8 | * function or via the LED class, if desired -- the hardware tends to |
| 9 | * encapsulate some of the same "triggers" that the LED class supports, |
| 10 | * so there's not too much value in it). |
| 11 | * |
| 12 | * Additionally, most of these boards also have a LED bank that we've |
| 13 | * traditionally used for strobing the load average. This use case is |
| 14 | * handled by this driver, rather than giving each LED bit position its |
| 15 | * own struct device. |
| 16 | * |
| 17 | * This file is subject to the terms and conditions of the GNU General Public |
| 18 | * License. See the file "COPYING" in the main directory of this archive |
| 19 | * for more details. |
| 20 | */ |
| 21 | #include <linux/init.h> |
| 22 | #include <linux/module.h> |
| 23 | #include <linux/platform_device.h> |
| 24 | #include <linux/sched.h> |
| 25 | #include <linux/timer.h> |
| 26 | #include <linux/io.h> |
| 27 | |
| 28 | #define DRV_NAME "heartbeat" |
| 29 | #define DRV_VERSION "0.1.0" |
| 30 | |
| 31 | struct heartbeat_data { |
| 32 | void __iomem *base; |
| 33 | unsigned char bit_pos[8]; |
| 34 | struct timer_list timer; |
| 35 | }; |
| 36 | |
| 37 | static void heartbeat_timer(unsigned long data) |
| 38 | { |
| 39 | struct heartbeat_data *hd = (struct heartbeat_data *)data; |
| 40 | static unsigned bit = 0, up = 1; |
| 41 | |
| 42 | ctrl_outw(1 << hd->bit_pos[bit], (unsigned long)hd->base); |
Takashi YOSHII | f607289 | 2007-03-12 15:33:22 +0900 | [diff] [blame] | 43 | bit += up; |
| 44 | if ((bit == 0) || (bit == ARRAY_SIZE(hd->bit_pos)-1)) |
| 45 | up = -up; |
Paul Mundt | 401e909 | 2007-02-13 15:46:39 +0900 | [diff] [blame] | 46 | |
| 47 | mod_timer(&hd->timer, jiffies + (110 - ((300 << FSHIFT) / |
| 48 | ((avenrun[0] / 5) + (3 << FSHIFT))))); |
| 49 | } |
| 50 | |
| 51 | static int heartbeat_drv_probe(struct platform_device *pdev) |
| 52 | { |
| 53 | struct resource *res; |
| 54 | struct heartbeat_data *hd; |
| 55 | |
| 56 | if (unlikely(pdev->num_resources != 1)) { |
| 57 | dev_err(&pdev->dev, "invalid number of resources\n"); |
| 58 | return -EINVAL; |
| 59 | } |
| 60 | |
| 61 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 62 | if (unlikely(res == NULL)) { |
| 63 | dev_err(&pdev->dev, "invalid resource\n"); |
| 64 | return -EINVAL; |
| 65 | } |
| 66 | |
| 67 | hd = kmalloc(sizeof(struct heartbeat_data), GFP_KERNEL); |
| 68 | if (unlikely(!hd)) |
| 69 | return -ENOMEM; |
| 70 | |
| 71 | if (pdev->dev.platform_data) { |
| 72 | memcpy(hd->bit_pos, pdev->dev.platform_data, |
| 73 | ARRAY_SIZE(hd->bit_pos)); |
| 74 | } else { |
| 75 | int i; |
| 76 | |
| 77 | for (i = 0; i < ARRAY_SIZE(hd->bit_pos); i++) |
| 78 | hd->bit_pos[i] = i; |
| 79 | } |
| 80 | |
Paul Mundt | bf73af2 | 2007-07-20 17:35:42 +0900 | [diff] [blame] | 81 | hd->base = (void __iomem *)(unsigned long)res->start; |
Paul Mundt | 401e909 | 2007-02-13 15:46:39 +0900 | [diff] [blame] | 82 | |
| 83 | setup_timer(&hd->timer, heartbeat_timer, (unsigned long)hd); |
| 84 | platform_set_drvdata(pdev, hd); |
| 85 | |
| 86 | return mod_timer(&hd->timer, jiffies + 1); |
| 87 | } |
| 88 | |
| 89 | static int heartbeat_drv_remove(struct platform_device *pdev) |
| 90 | { |
| 91 | struct heartbeat_data *hd = platform_get_drvdata(pdev); |
| 92 | |
| 93 | del_timer_sync(&hd->timer); |
| 94 | |
| 95 | platform_set_drvdata(pdev, NULL); |
| 96 | |
| 97 | kfree(hd); |
| 98 | |
| 99 | return 0; |
| 100 | } |
| 101 | |
| 102 | static struct platform_driver heartbeat_driver = { |
| 103 | .probe = heartbeat_drv_probe, |
| 104 | .remove = heartbeat_drv_remove, |
| 105 | .driver = { |
| 106 | .name = DRV_NAME, |
| 107 | }, |
| 108 | }; |
| 109 | |
| 110 | static int __init heartbeat_init(void) |
| 111 | { |
| 112 | printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION); |
| 113 | return platform_driver_register(&heartbeat_driver); |
| 114 | } |
| 115 | |
| 116 | static void __exit heartbeat_exit(void) |
| 117 | { |
| 118 | platform_driver_unregister(&heartbeat_driver); |
| 119 | } |
| 120 | module_init(heartbeat_init); |
| 121 | module_exit(heartbeat_exit); |
| 122 | |
| 123 | MODULE_VERSION(DRV_VERSION); |
| 124 | MODULE_AUTHOR("Paul Mundt"); |
| 125 | MODULE_LICENSE("GPLv2"); |