Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shaggy...
[linux-2.6] / drivers / misc / atmel_tclib.c
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);