tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 */
22const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
23EXPORT_SYMBOL(atmel_tc_divisors);
24
25#elif defined(CONFIG_ARCH_AT91)
26/* AT91 has these divide MCK */
27const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
28EXPORT_SYMBOL(atmel_tc_divisors);
29
30#endif
31
32static DEFINE_SPINLOCK(tc_list_lock);
33static 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 */
44struct 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
72out:
73 spin_unlock(&tc_list_lock);
74 return tc;
75
76fail_ioremap:
77 release_resource(r);
78fail:
79 tc = NULL;
80 goto out;
81}
82EXPORT_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 */
92void 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}
103EXPORT_SYMBOL_GPL(atmel_tc_free);
104
105static 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
153static struct platform_driver tc_driver = {
154 .driver.name = "atmel_tcb",
155};
156
157static int __init tc_init(void)
158{
159 return platform_driver_probe(&tc_driver, tc_probe);
160}
161arch_initcall(tc_init);