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ff4a7481 | 1 | // SPDX-License-Identifier: GPL-2.0 |
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2 | /* |
3 | * Generic heartbeat driver for regular LED banks | |
4 | * | |
10ab92d8 | 5 | * Copyright (C) 2007 - 2010 Paul Mundt |
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6 | * |
7 | * Most SH reference boards include a number of individual LEDs that can | |
8 | * be independently controlled (either via a pre-defined hardware | |
9 | * function or via the LED class, if desired -- the hardware tends to | |
10 | * encapsulate some of the same "triggers" that the LED class supports, | |
11 | * so there's not too much value in it). | |
12 | * | |
13 | * Additionally, most of these boards also have a LED bank that we've | |
14 | * traditionally used for strobing the load average. This use case is | |
15 | * handled by this driver, rather than giving each LED bit position its | |
16 | * own struct device. | |
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17 | */ |
18 | #include <linux/init.h> | |
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19 | #include <linux/platform_device.h> |
20 | #include <linux/sched.h> | |
4f17722c | 21 | #include <linux/sched/loadavg.h> |
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22 | #include <linux/timer.h> |
23 | #include <linux/io.h> | |
5a0e3ad6 | 24 | #include <linux/slab.h> |
8786c952 | 25 | #include <asm/heartbeat.h> |
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26 | |
27 | #define DRV_NAME "heartbeat" | |
10ab92d8 | 28 | #define DRV_VERSION "0.1.2" |
401e9093 | 29 | |
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30 | static unsigned char default_bit_pos[] = { 0, 1, 2, 3, 4, 5, 6, 7 }; |
31 | ||
32 | static inline void heartbeat_toggle_bit(struct heartbeat_data *hd, | |
33 | unsigned bit, unsigned int inverted) | |
34 | { | |
35 | unsigned int new; | |
36 | ||
37 | new = (1 << hd->bit_pos[bit]); | |
38 | if (inverted) | |
39 | new = ~new; | |
40 | ||
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41 | new &= hd->mask; |
42 | ||
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43 | switch (hd->regsize) { |
44 | case 32: | |
e174d130 | 45 | new |= ioread32(hd->base) & ~hd->mask; |
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46 | iowrite32(new, hd->base); |
47 | break; | |
48 | case 16: | |
e174d130 | 49 | new |= ioread16(hd->base) & ~hd->mask; |
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50 | iowrite16(new, hd->base); |
51 | break; | |
52 | default: | |
e174d130 | 53 | new |= ioread8(hd->base) & ~hd->mask; |
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54 | iowrite8(new, hd->base); |
55 | break; | |
56 | } | |
57 | } | |
401e9093 | 58 | |
e99e88a9 | 59 | static void heartbeat_timer(struct timer_list *t) |
401e9093 | 60 | { |
e99e88a9 | 61 | struct heartbeat_data *hd = from_timer(hd, t, timer); |
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62 | static unsigned bit = 0, up = 1; |
63 | ||
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64 | heartbeat_toggle_bit(hd, bit, hd->flags & HEARTBEAT_INVERTED); |
65 | ||
f6072896 | 66 | bit += up; |
8786c952 | 67 | if ((bit == 0) || (bit == (hd->nr_bits)-1)) |
f6072896 | 68 | up = -up; |
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69 | |
70 | mod_timer(&hd->timer, jiffies + (110 - ((300 << FSHIFT) / | |
71 | ((avenrun[0] / 5) + (3 << FSHIFT))))); | |
72 | } | |
73 | ||
74 | static int heartbeat_drv_probe(struct platform_device *pdev) | |
75 | { | |
76 | struct resource *res; | |
77 | struct heartbeat_data *hd; | |
e174d130 | 78 | int i; |
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79 | |
80 | if (unlikely(pdev->num_resources != 1)) { | |
81 | dev_err(&pdev->dev, "invalid number of resources\n"); | |
82 | return -EINVAL; | |
83 | } | |
84 | ||
85 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
86 | if (unlikely(res == NULL)) { | |
87 | dev_err(&pdev->dev, "invalid resource\n"); | |
88 | return -EINVAL; | |
89 | } | |
90 | ||
401e9093 | 91 | if (pdev->dev.platform_data) { |
8786c952 | 92 | hd = pdev->dev.platform_data; |
401e9093 | 93 | } else { |
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94 | hd = kzalloc(sizeof(struct heartbeat_data), GFP_KERNEL); |
95 | if (unlikely(!hd)) | |
96 | return -ENOMEM; | |
97 | } | |
98 | ||
4bdc0d67 | 99 | hd->base = ioremap(res->start, resource_size(res)); |
1de83e94 | 100 | if (unlikely(!hd->base)) { |
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101 | dev_err(&pdev->dev, "ioremap failed\n"); |
102 | ||
103 | if (!pdev->dev.platform_data) | |
104 | kfree(hd); | |
105 | ||
106 | return -ENXIO; | |
107 | } | |
401e9093 | 108 | |
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109 | if (!hd->nr_bits) { |
110 | hd->bit_pos = default_bit_pos; | |
111 | hd->nr_bits = ARRAY_SIZE(default_bit_pos); | |
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112 | } |
113 | ||
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114 | hd->mask = 0; |
115 | for (i = 0; i < hd->nr_bits; i++) | |
116 | hd->mask |= (1 << hd->bit_pos[i]); | |
117 | ||
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118 | if (!hd->regsize) { |
119 | switch (res->flags & IORESOURCE_MEM_TYPE_MASK) { | |
120 | case IORESOURCE_MEM_32BIT: | |
121 | hd->regsize = 32; | |
122 | break; | |
123 | case IORESOURCE_MEM_16BIT: | |
124 | hd->regsize = 16; | |
125 | break; | |
126 | case IORESOURCE_MEM_8BIT: | |
127 | default: | |
128 | hd->regsize = 8; | |
129 | break; | |
130 | } | |
131 | } | |
401e9093 | 132 | |
e99e88a9 | 133 | timer_setup(&hd->timer, heartbeat_timer, 0); |
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134 | platform_set_drvdata(pdev, hd); |
135 | ||
136 | return mod_timer(&hd->timer, jiffies + 1); | |
137 | } | |
138 | ||
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139 | static struct platform_driver heartbeat_driver = { |
140 | .probe = heartbeat_drv_probe, | |
401e9093 | 141 | .driver = { |
e75438e2 PG |
142 | .name = DRV_NAME, |
143 | .suppress_bind_attrs = true, | |
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144 | }, |
145 | }; | |
146 | ||
147 | static int __init heartbeat_init(void) | |
148 | { | |
149 | printk(KERN_NOTICE DRV_NAME ": version %s loaded\n", DRV_VERSION); | |
150 | return platform_driver_register(&heartbeat_driver); | |
151 | } | |
e75438e2 | 152 | device_initcall(heartbeat_init); |