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2a341f5c DB |
1 | #include <linux/atmel_tc.h> |
2 | #include <linux/clk.h> | |
3 | #include <linux/err.h> | |
4 | #include <linux/init.h> | |
5 | #include <linux/io.h> | |
6 | #include <linux/ioport.h> | |
7 | #include <linux/kernel.h> | |
8 | #include <linux/platform_device.h> | |
9 | ||
10 | /* Number of bytes to reserve for the iomem resource */ | |
11 | #define ATMEL_TC_IOMEM_SIZE 256 | |
12 | ||
13 | ||
14 | /* | |
15 | * This is a thin library to solve the problem of how to portably allocate | |
16 | * one of the TC blocks. For simplicity, it doesn't currently expect to | |
17 | * share individual timers between different drivers. | |
18 | */ | |
19 | ||
20 | #if defined(CONFIG_AVR32) | |
21 | /* AVR32 has these divide PBB */ | |
22 | const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, }; | |
23 | EXPORT_SYMBOL(atmel_tc_divisors); | |
24 | ||
25 | #elif defined(CONFIG_ARCH_AT91) | |
26 | /* AT91 has these divide MCK */ | |
27 | const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, }; | |
28 | EXPORT_SYMBOL(atmel_tc_divisors); | |
29 | ||
30 | #endif | |
31 | ||
32 | static DEFINE_SPINLOCK(tc_list_lock); | |
33 | static LIST_HEAD(tc_list); | |
34 | ||
35 | /** | |
36 | * atmel_tc_alloc - allocate a specified TC block | |
37 | * @block: which block to allocate | |
38 | * @name: name to be associated with the iomem resource | |
39 | * | |
40 | * Caller allocates a block. If it is available, a pointer to a | |
41 | * pre-initialized struct atmel_tc is returned. The caller can access | |
42 | * the registers directly through the "regs" field. | |
43 | */ | |
44 | struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name) | |
45 | { | |
46 | struct atmel_tc *tc; | |
47 | struct platform_device *pdev = NULL; | |
48 | struct resource *r; | |
49 | ||
50 | spin_lock(&tc_list_lock); | |
51 | list_for_each_entry(tc, &tc_list, node) { | |
52 | if (tc->pdev->id == block) { | |
53 | pdev = tc->pdev; | |
54 | break; | |
55 | } | |
56 | } | |
57 | ||
58 | if (!pdev || tc->iomem) | |
59 | goto fail; | |
60 | ||
61 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
62 | r = request_mem_region(r->start, ATMEL_TC_IOMEM_SIZE, name); | |
63 | if (!r) | |
64 | goto fail; | |
65 | ||
66 | tc->regs = ioremap(r->start, ATMEL_TC_IOMEM_SIZE); | |
67 | if (!tc->regs) | |
68 | goto fail_ioremap; | |
69 | ||
70 | tc->iomem = r; | |
71 | ||
72 | out: | |
73 | spin_unlock(&tc_list_lock); | |
74 | return tc; | |
75 | ||
76 | fail_ioremap: | |
77 | release_resource(r); | |
78 | fail: | |
79 | tc = NULL; | |
80 | goto out; | |
81 | } | |
82 | EXPORT_SYMBOL_GPL(atmel_tc_alloc); | |
83 | ||
84 | /** | |
85 | * atmel_tc_free - release a specified TC block | |
86 | * @tc: Timer/counter block that was returned by atmel_tc_alloc() | |
87 | * | |
88 | * This reverses the effect of atmel_tc_alloc(), unmapping the I/O | |
89 | * registers, invalidating the resource returned by that routine and | |
90 | * making the TC available to other drivers. | |
91 | */ | |
92 | void atmel_tc_free(struct atmel_tc *tc) | |
93 | { | |
94 | spin_lock(&tc_list_lock); | |
95 | if (tc->regs) { | |
96 | iounmap(tc->regs); | |
97 | release_resource(tc->iomem); | |
98 | tc->regs = NULL; | |
99 | tc->iomem = NULL; | |
100 | } | |
101 | spin_unlock(&tc_list_lock); | |
102 | } | |
103 | EXPORT_SYMBOL_GPL(atmel_tc_free); | |
104 | ||
105 | static int __init tc_probe(struct platform_device *pdev) | |
106 | { | |
107 | struct atmel_tc *tc; | |
108 | struct clk *clk; | |
109 | int irq; | |
110 | ||
111 | if (!platform_get_resource(pdev, IORESOURCE_MEM, 0)) | |
112 | return -EINVAL; | |
113 | ||
114 | irq = platform_get_irq(pdev, 0); | |
115 | if (irq < 0) | |
116 | return -EINVAL; | |
117 | ||
118 | tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL); | |
119 | if (!tc) | |
120 | return -ENOMEM; | |
121 | ||
122 | tc->pdev = pdev; | |
123 | ||
124 | clk = clk_get(&pdev->dev, "t0_clk"); | |
125 | if (IS_ERR(clk)) { | |
126 | kfree(tc); | |
127 | return -EINVAL; | |
128 | } | |
129 | ||
130 | tc->clk[0] = clk; | |
131 | tc->clk[1] = clk_get(&pdev->dev, "t1_clk"); | |
132 | if (IS_ERR(tc->clk[1])) | |
133 | tc->clk[1] = clk; | |
134 | tc->clk[2] = clk_get(&pdev->dev, "t2_clk"); | |
135 | if (IS_ERR(tc->clk[2])) | |
136 | tc->clk[2] = clk; | |
137 | ||
138 | tc->irq[0] = irq; | |
139 | tc->irq[1] = platform_get_irq(pdev, 1); | |
140 | if (tc->irq[1] < 0) | |
141 | tc->irq[1] = irq; | |
142 | tc->irq[2] = platform_get_irq(pdev, 2); | |
143 | if (tc->irq[2] < 0) | |
144 | tc->irq[2] = irq; | |
145 | ||
146 | spin_lock(&tc_list_lock); | |
147 | list_add_tail(&tc->node, &tc_list); | |
148 | spin_unlock(&tc_list_lock); | |
149 | ||
150 | return 0; | |
151 | } | |
152 | ||
153 | static struct platform_driver tc_driver = { | |
154 | .driver.name = "atmel_tcb", | |
155 | }; | |
156 | ||
157 | static int __init tc_init(void) | |
158 | { | |
159 | return platform_driver_probe(&tc_driver, tc_probe); | |
160 | } | |
161 | arch_initcall(tc_init); |