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401e9093 PM |
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> | |
8786c952 | 27 | #include <asm/heartbeat.h> |
401e9093 PM |
28 | |
29 | #define DRV_NAME "heartbeat" | |
8786c952 | 30 | #define DRV_VERSION "0.1.1" |
401e9093 | 31 | |
8786c952 PM |
32 | static unsigned char default_bit_pos[] = { 0, 1, 2, 3, 4, 5, 6, 7 }; |
33 | ||
34 | static inline void heartbeat_toggle_bit(struct heartbeat_data *hd, | |
35 | unsigned bit, unsigned int inverted) | |
36 | { | |
37 | unsigned int new; | |
38 | ||
39 | new = (1 << hd->bit_pos[bit]); | |
40 | if (inverted) | |
41 | new = ~new; | |
42 | ||
43 | switch (hd->regsize) { | |
44 | case 32: | |
45 | iowrite32(new, hd->base); | |
46 | break; | |
47 | case 16: | |
48 | iowrite16(new, hd->base); | |
49 | break; | |
50 | default: | |
51 | iowrite8(new, hd->base); | |
52 | break; | |
53 | } | |
54 | } | |
401e9093 PM |
55 | |
56 | static void heartbeat_timer(unsigned long data) | |
57 | { | |
58 | struct heartbeat_data *hd = (struct heartbeat_data *)data; | |
59 | static unsigned bit = 0, up = 1; | |
60 | ||
8786c952 PM |
61 | heartbeat_toggle_bit(hd, bit, hd->flags & HEARTBEAT_INVERTED); |
62 | ||
f6072896 | 63 | bit += up; |
8786c952 | 64 | if ((bit == 0) || (bit == (hd->nr_bits)-1)) |
f6072896 | 65 | up = -up; |
401e9093 PM |
66 | |
67 | mod_timer(&hd->timer, jiffies + (110 - ((300 << FSHIFT) / | |
68 | ((avenrun[0] / 5) + (3 << FSHIFT))))); | |
69 | } | |
70 | ||
71 | static int heartbeat_drv_probe(struct platform_device *pdev) | |
72 | { | |
73 | struct resource *res; | |
74 | struct heartbeat_data *hd; | |
75 | ||
76 | if (unlikely(pdev->num_resources != 1)) { | |
77 | dev_err(&pdev->dev, "invalid number of resources\n"); | |
78 | return -EINVAL; | |
79 | } | |
80 | ||
81 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
82 | if (unlikely(res == NULL)) { | |
83 | dev_err(&pdev->dev, "invalid resource\n"); | |
84 | return -EINVAL; | |
85 | } | |
86 | ||
401e9093 | 87 | if (pdev->dev.platform_data) { |
8786c952 | 88 | hd = pdev->dev.platform_data; |
401e9093 | 89 | } else { |
8786c952 PM |
90 | hd = kzalloc(sizeof(struct heartbeat_data), GFP_KERNEL); |
91 | if (unlikely(!hd)) | |
92 | return -ENOMEM; | |
93 | } | |
94 | ||
95 | hd->base = ioremap_nocache(res->start, res->end - res->start + 1); | |
1de83e94 | 96 | if (unlikely(!hd->base)) { |
8786c952 PM |
97 | dev_err(&pdev->dev, "ioremap failed\n"); |
98 | ||
99 | if (!pdev->dev.platform_data) | |
100 | kfree(hd); | |
101 | ||
102 | return -ENXIO; | |
103 | } | |
401e9093 | 104 | |
8786c952 PM |
105 | if (!hd->nr_bits) { |
106 | hd->bit_pos = default_bit_pos; | |
107 | hd->nr_bits = ARRAY_SIZE(default_bit_pos); | |
401e9093 PM |
108 | } |
109 | ||
8786c952 PM |
110 | if (!hd->regsize) |
111 | hd->regsize = 8; /* default access size */ | |
401e9093 PM |
112 | |
113 | setup_timer(&hd->timer, heartbeat_timer, (unsigned long)hd); | |
114 | platform_set_drvdata(pdev, hd); | |
115 | ||
116 | return mod_timer(&hd->timer, jiffies + 1); | |
117 | } | |
118 | ||
119 | static int heartbeat_drv_remove(struct platform_device *pdev) | |
120 | { | |
121 | struct heartbeat_data *hd = platform_get_drvdata(pdev); | |
122 | ||
123 | del_timer_sync(&hd->timer); | |
8786c952 | 124 | iounmap(hd->base); |
401e9093 PM |
125 | |
126 | platform_set_drvdata(pdev, NULL); | |
127 | ||
8786c952 PM |
128 | if (!pdev->dev.platform_data) |
129 | kfree(hd); | |
401e9093 PM |
130 | |
131 | return 0; | |
132 | } | |
133 | ||
134 | static struct platform_driver heartbeat_driver = { | |
135 | .probe = heartbeat_drv_probe, | |
136 | .remove = heartbeat_drv_remove, | |
137 | .driver = { | |
138 | .name = DRV_NAME, | |
139 | }, | |
140 | }; | |
141 | ||
142 | static int __init heartbeat_init(void) | |
143 | { | |
144 | printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION); | |
145 | return platform_driver_register(&heartbeat_driver); | |
146 | } | |
147 | ||
148 | static void __exit heartbeat_exit(void) | |
149 | { | |
150 | platform_driver_unregister(&heartbeat_driver); | |
151 | } | |
152 | module_init(heartbeat_init); | |
153 | module_exit(heartbeat_exit); | |
154 | ||
155 | MODULE_VERSION(DRV_VERSION); | |
156 | MODULE_AUTHOR("Paul Mundt"); | |
839cd310 | 157 | MODULE_LICENSE("GPL v2"); |