Tegra CEC Support
[linux-2.6.git] / 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 #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 */
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         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
83 out:
84         spin_unlock(&tc_list_lock);
85         return tc;
86
87 fail_ioremap:
88         release_mem_region(r->start, size);
89 fail:
90         tc = NULL;
91         goto out;
92 }
93 EXPORT_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  */
103 void 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 }
114 EXPORT_SYMBOL_GPL(atmel_tc_free);
115
116 #if defined(CONFIG_OF)
117 static struct atmel_tcb_config tcb_rm9200_config = {
118         .counter_width = 16,
119 };
120
121 static struct atmel_tcb_config tcb_sam9x5_config = {
122         .counter_width = 32,
123 };
124
125 static 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
137 MODULE_DEVICE_TABLE(of, atmel_tcb_dt_ids);
138 #endif
139
140 static 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
196 static 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
203 static int __init tc_init(void)
204 {
205         return platform_driver_probe(&tc_driver, tc_probe);
206 }
207 arch_initcall(tc_init);