summaryrefslogtreecommitdiffstats
path: root/drivers/misc/atmel_tclib.c
blob: c8d8e38d0d8ae6dc47cc0d85b581388896ae5361 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
#include <linux/atmel_tc.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/of.h>

/*
 * This is a thin library to solve the problem of how to portably allocate
 * one of the TC blocks.  For simplicity, it doesn't currently expect to
 * share individual timers between different drivers.
 */

#if defined(CONFIG_AVR32)
/* AVR32 has these divide PBB */
const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
EXPORT_SYMBOL(atmel_tc_divisors);

#elif defined(CONFIG_ARCH_AT91)
/* AT91 has these divide MCK */
const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
EXPORT_SYMBOL(atmel_tc_divisors);

#endif

static DEFINE_SPINLOCK(tc_list_lock);
static LIST_HEAD(tc_list);

/**
 * atmel_tc_alloc - allocate a specified TC block
 * @block: which block to allocate
 * @name: name to be associated with the iomem resource
 *
 * Caller allocates a block.  If it is available, a pointer to a
 * pre-initialized struct atmel_tc is returned. The caller can access
 * the registers directly through the "regs" field.
 */
struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name)
{
	struct atmel_tc		*tc;
	struct platform_device	*pdev = NULL;
	struct resource		*r;
	size_t			size;

	spin_lock(&tc_list_lock);
	list_for_each_entry(tc, &tc_list, node) {
		if (tc->pdev->dev.of_node) {
			if (of_alias_get_id(tc->pdev->dev.of_node, "tcb")
					== block) {
				pdev = tc->pdev;
				break;
			}
		} else if (tc->pdev->id == block) {
			pdev = tc->pdev;
			break;
		}
	}

	if (!pdev || tc->iomem)
		goto fail;

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!r)
		goto fail;

	size = resource_size(r);
	r = request_mem_region(r->start, size, name);
	if (!r)
		goto fail;

	tc->regs = ioremap(r->start, size);
	if (!tc->regs)
		goto fail_ioremap;

	tc->iomem = r;

out:
	spin_unlock(&tc_list_lock);
	return tc;

fail_ioremap:
	release_mem_region(r->start, size);
fail:
	tc = NULL;
	goto out;
}
EXPORT_SYMBOL_GPL(atmel_tc_alloc);

/**
 * atmel_tc_free - release a specified TC block
 * @tc: Timer/counter block that was returned by atmel_tc_alloc()
 *
 * This reverses the effect of atmel_tc_alloc(), unmapping the I/O
 * registers, invalidating the resource returned by that routine and
 * making the TC available to other drivers.
 */
void atmel_tc_free(struct atmel_tc *tc)
{
	spin_lock(&tc_list_lock);
	if (tc->regs) {
		iounmap(tc->regs);
		release_mem_region(tc->iomem->start, resource_size(tc->iomem));
		tc->regs = NULL;
		tc->iomem = NULL;
	}
	spin_unlock(&tc_list_lock);
}
EXPORT_SYMBOL_GPL(atmel_tc_free);

#if defined(CONFIG_OF)
static struct atmel_tcb_config tcb_rm9200_config = {
	.counter_width = 16,
};

static struct atmel_tcb_config tcb_sam9x5_config = {
	.counter_width = 32,
};

static const struct of_device_id atmel_tcb_dt_ids[] = {
	{
		.compatible = "atmel,at91rm9200-tcb",
		.data = &tcb_rm9200_config,
	}, {
		.compatible = "atmel,at91sam9x5-tcb",
		.data = &tcb_sam9x5_config,
	}, {
		/* sentinel */
	}
};

MODULE_DEVICE_TABLE(of, atmel_tcb_dt_ids);
#endif

static int __init tc_probe(struct platform_device *pdev)
{
	struct atmel_tc *tc;
	struct clk	*clk;
	int		irq;

	if (!platform_get_resource(pdev, IORESOURCE_MEM, 0))
		return -EINVAL;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return -EINVAL;

	tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL);
	if (!tc)
		return -ENOMEM;

	tc->pdev = pdev;

	clk = clk_get(&pdev->dev, "t0_clk");
	if (IS_ERR(clk)) {
		kfree(tc);
		return -EINVAL;
	}

	/* Now take SoC information if available */
	if (pdev->dev.of_node) {
		const struct of_device_id *match;
		match = of_match_node(atmel_tcb_dt_ids, pdev->dev.of_node);
		if (match)
			tc->tcb_config = match->data;
	}

	tc->clk[0] = clk;
	tc->clk[1] = clk_get(&pdev->dev, "t1_clk");
	if (IS_ERR(tc->clk[1]))
		tc->clk[1] = clk;
	tc->clk[2] = clk_get(&pdev->dev, "t2_clk");
	if (IS_ERR(tc->clk[2]))
		tc->clk[2] = clk;

	tc->irq[0] = irq;
	tc->irq[1] = platform_get_irq(pdev, 1);
	if (tc->irq[1] < 0)
		tc->irq[1] = irq;
	tc->irq[2] = platform_get_irq(pdev, 2);
	if (tc->irq[2] < 0)
		tc->irq[2] = irq;

	spin_lock(&tc_list_lock);
	list_add_tail(&tc->node, &tc_list);
	spin_unlock(&tc_list_lock);

	return 0;
}

static struct platform_driver tc_driver = {
	.driver = {
		.name	= "atmel_tcb",
		.of_match_table	= of_match_ptr(atmel_tcb_dt_ids),
	},
};

static int __init tc_init(void)
{
	return platform_driver_probe(&tc_driver, tc_probe);
}
arch_initcall(tc_init);