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#include <linux/module.h>
10#include <linux/slab.h>
11#include <linux/export.h>
12#include <linux/of.h>
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 size_t size;
50
51 spin_lock(&tc_list_lock);
52 list_for_each_entry(tc, &tc_list, node) {
53 if (tc->pdev->dev.of_node) {
54 if (of_alias_get_id(tc->pdev->dev.of_node, "tcb")
55 == block) {
56 pdev = tc->pdev;
57 break;
58 }
59 } else if (tc->pdev->id == block) {
60 pdev = tc->pdev;
61 break;
62 }
63 }
64
65 if (!pdev || tc->iomem)
66 goto fail;
67
68 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
69 if (!r)
70 goto fail;
71
72 size = resource_size(r);
73 r = request_mem_region(r->start, size, name);
74 if (!r)
75 goto fail;
76
77 tc->regs = ioremap(r->start, size);
78 if (!tc->regs)
79 goto fail_ioremap;
80
81 tc->iomem = r;
82
83out:
84 spin_unlock(&tc_list_lock);
85 return tc;
86
87fail_ioremap:
88 release_mem_region(r->start, size);
89fail:
90 tc = NULL;
91 goto out;
92}
93EXPORT_SYMBOL_GPL(atmel_tc_alloc);
94
95/**
96 * atmel_tc_free - release a specified TC block
97 * @tc: Timer/counter block that was returned by atmel_tc_alloc()
98 *
99 * This reverses the effect of atmel_tc_alloc(), unmapping the I/O
100 * registers, invalidating the resource returned by that routine and
101 * making the TC available to other drivers.
102 */
103void atmel_tc_free(struct atmel_tc *tc)
104{
105 spin_lock(&tc_list_lock);
106 if (tc->regs) {
107 iounmap(tc->regs);
108 release_mem_region(tc->iomem->start, resource_size(tc->iomem));
109 tc->regs = NULL;
110 tc->iomem = NULL;
111 }
112 spin_unlock(&tc_list_lock);
113}
114EXPORT_SYMBOL_GPL(atmel_tc_free);
115
116#if defined(CONFIG_OF)
117static struct atmel_tcb_config tcb_rm9200_config = {
118 .counter_width = 16,
119};
120
121static struct atmel_tcb_config tcb_sam9x5_config = {
122 .counter_width = 32,
123};
124
125static const struct of_device_id atmel_tcb_dt_ids[] = {
126 {
127 .compatible = "atmel,at91rm9200-tcb",
128 .data = &tcb_rm9200_config,
129 }, {
130 .compatible = "atmel,at91sam9x5-tcb",
131 .data = &tcb_sam9x5_config,
132 }, {
133 /* sentinel */
134 }
135};
136
137MODULE_DEVICE_TABLE(of, atmel_tcb_dt_ids);
138#endif
139
140static int __init tc_probe(struct platform_device *pdev)
141{
142 struct atmel_tc *tc;
143 struct clk *clk;
144 int irq;
145
146 if (!platform_get_resource(pdev, IORESOURCE_MEM, 0))
147 return -EINVAL;
148
149 irq = platform_get_irq(pdev, 0);
150 if (irq < 0)
151 return -EINVAL;
152
153 tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL);
154 if (!tc)
155 return -ENOMEM;
156
157 tc->pdev = pdev;
158
159 clk = clk_get(&pdev->dev, "t0_clk");
160 if (IS_ERR(clk)) {
161 kfree(tc);
162 return -EINVAL;
163 }
164
165 /* Now take SoC information if available */
166 if (pdev->dev.of_node) {
167 const struct of_device_id *match;
168 match = of_match_node(atmel_tcb_dt_ids, pdev->dev.of_node);
169 if (match)
170 tc->tcb_config = match->data;
171 }
172
173 tc->clk[0] = clk;
174 tc->clk[1] = clk_get(&pdev->dev, "t1_clk");
175 if (IS_ERR(tc->clk[1]))
176 tc->clk[1] = clk;
177 tc->clk[2] = clk_get(&pdev->dev, "t2_clk");
178 if (IS_ERR(tc->clk[2]))
179 tc->clk[2] = clk;
180
181 tc->irq[0] = irq;
182 tc->irq[1] = platform_get_irq(pdev, 1);
183 if (tc->irq[1] < 0)
184 tc->irq[1] = irq;
185 tc->irq[2] = platform_get_irq(pdev, 2);
186 if (tc->irq[2] < 0)
187 tc->irq[2] = irq;
188
189 spin_lock(&tc_list_lock);
190 list_add_tail(&tc->node, &tc_list);
191 spin_unlock(&tc_list_lock);
192
193 return 0;
194}
195
196static struct platform_driver tc_driver = {
197 .driver = {
198 .name = "atmel_tcb",
199 .of_match_table = of_match_ptr(atmel_tcb_dt_ids),
200 },
201};
202
203static int __init tc_init(void)
204{
205 return platform_driver_probe(&tc_driver, tc_probe);
206}
207arch_initcall(tc_init);