blob: a844810b50f68a6a88e12ed7a427862a044efc48 [file] [log] [blame]
David Brownell2a341f52008-02-22 17:23:23 -08001#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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09009#include <linux/slab.h>
David Brownell2a341f52008-02-22 17:23:23 -080010
11/* Number of bytes to reserve for the iomem resource */
12#define ATMEL_TC_IOMEM_SIZE 256
13
14
15/*
16 * This is a thin library to solve the problem of how to portably allocate
17 * one of the TC blocks. For simplicity, it doesn't currently expect to
18 * share individual timers between different drivers.
19 */
20
21#if defined(CONFIG_AVR32)
22/* AVR32 has these divide PBB */
23const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
24EXPORT_SYMBOL(atmel_tc_divisors);
25
26#elif defined(CONFIG_ARCH_AT91)
27/* AT91 has these divide MCK */
28const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
29EXPORT_SYMBOL(atmel_tc_divisors);
30
31#endif
32
33static DEFINE_SPINLOCK(tc_list_lock);
34static LIST_HEAD(tc_list);
35
36/**
37 * atmel_tc_alloc - allocate a specified TC block
38 * @block: which block to allocate
39 * @name: name to be associated with the iomem resource
40 *
41 * Caller allocates a block. If it is available, a pointer to a
42 * pre-initialized struct atmel_tc is returned. The caller can access
43 * the registers directly through the "regs" field.
44 */
45struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name)
46{
47 struct atmel_tc *tc;
48 struct platform_device *pdev = NULL;
49 struct resource *r;
50
51 spin_lock(&tc_list_lock);
52 list_for_each_entry(tc, &tc_list, node) {
53 if (tc->pdev->id == block) {
54 pdev = tc->pdev;
55 break;
56 }
57 }
58
59 if (!pdev || tc->iomem)
60 goto fail;
61
62 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
63 r = request_mem_region(r->start, ATMEL_TC_IOMEM_SIZE, name);
64 if (!r)
65 goto fail;
66
67 tc->regs = ioremap(r->start, ATMEL_TC_IOMEM_SIZE);
68 if (!tc->regs)
69 goto fail_ioremap;
70
71 tc->iomem = r;
72
73out:
74 spin_unlock(&tc_list_lock);
75 return tc;
76
77fail_ioremap:
Axel Lina844b432011-03-22 16:34:01 -070078 release_mem_region(r->start, ATMEL_TC_IOMEM_SIZE);
David Brownell2a341f52008-02-22 17:23:23 -080079fail:
80 tc = NULL;
81 goto out;
82}
83EXPORT_SYMBOL_GPL(atmel_tc_alloc);
84
85/**
86 * atmel_tc_free - release a specified TC block
87 * @tc: Timer/counter block that was returned by atmel_tc_alloc()
88 *
89 * This reverses the effect of atmel_tc_alloc(), unmapping the I/O
90 * registers, invalidating the resource returned by that routine and
91 * making the TC available to other drivers.
92 */
93void atmel_tc_free(struct atmel_tc *tc)
94{
95 spin_lock(&tc_list_lock);
96 if (tc->regs) {
97 iounmap(tc->regs);
Axel Lina844b432011-03-22 16:34:01 -070098 release_mem_region(tc->iomem->start, ATMEL_TC_IOMEM_SIZE);
David Brownell2a341f52008-02-22 17:23:23 -080099 tc->regs = NULL;
100 tc->iomem = NULL;
101 }
102 spin_unlock(&tc_list_lock);
103}
104EXPORT_SYMBOL_GPL(atmel_tc_free);
105
106static int __init tc_probe(struct platform_device *pdev)
107{
108 struct atmel_tc *tc;
109 struct clk *clk;
110 int irq;
111
112 if (!platform_get_resource(pdev, IORESOURCE_MEM, 0))
113 return -EINVAL;
114
115 irq = platform_get_irq(pdev, 0);
116 if (irq < 0)
117 return -EINVAL;
118
119 tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL);
120 if (!tc)
121 return -ENOMEM;
122
123 tc->pdev = pdev;
124
125 clk = clk_get(&pdev->dev, "t0_clk");
126 if (IS_ERR(clk)) {
127 kfree(tc);
128 return -EINVAL;
129 }
130
131 tc->clk[0] = clk;
132 tc->clk[1] = clk_get(&pdev->dev, "t1_clk");
133 if (IS_ERR(tc->clk[1]))
134 tc->clk[1] = clk;
135 tc->clk[2] = clk_get(&pdev->dev, "t2_clk");
136 if (IS_ERR(tc->clk[2]))
137 tc->clk[2] = clk;
138
139 tc->irq[0] = irq;
140 tc->irq[1] = platform_get_irq(pdev, 1);
141 if (tc->irq[1] < 0)
142 tc->irq[1] = irq;
143 tc->irq[2] = platform_get_irq(pdev, 2);
144 if (tc->irq[2] < 0)
145 tc->irq[2] = irq;
146
147 spin_lock(&tc_list_lock);
148 list_add_tail(&tc->node, &tc_list);
149 spin_unlock(&tc_list_lock);
150
151 return 0;
152}
153
154static struct platform_driver tc_driver = {
155 .driver.name = "atmel_tcb",
156};
157
158static int __init tc_init(void)
159{
160 return platform_driver_probe(&tc_driver, tc_probe);
161}
162arch_initcall(tc_init);