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 *
39 * Caller allocates a block. If it is available, a pointer to a
40 * pre-initialized struct atmel_tc is returned. The caller can access
41 * the registers directly through the "regs" field.
42 */
43struct atmel_tc *atmel_tc_alloc(unsigned block)
44{
45 struct atmel_tc *tc;
46 struct platform_device *pdev = NULL;
47
48 spin_lock(&tc_list_lock);
49 list_for_each_entry(tc, &tc_list, node) {
50 if (tc->allocated)
51 continue;
52
53 if ((tc->pdev->dev.of_node && tc->id == block) ||
54 (tc->pdev->id == block)) {
55 pdev = tc->pdev;
56 tc->allocated = true;
57 break;
58 }
59 }
60 spin_unlock(&tc_list_lock);
61
62 return pdev ? tc : NULL;
63}
64EXPORT_SYMBOL_GPL(atmel_tc_alloc);
65
66/**
67 * atmel_tc_free - release a specified TC block
68 * @tc: Timer/counter block that was returned by atmel_tc_alloc()
69 *
70 * This reverses the effect of atmel_tc_alloc(), invalidating the resource
71 * returned by that routine and making the TC available to other drivers.
72 */
73void atmel_tc_free(struct atmel_tc *tc)
74{
75 spin_lock(&tc_list_lock);
76 if (tc->allocated)
77 tc->allocated = false;
78 spin_unlock(&tc_list_lock);
79}
80EXPORT_SYMBOL_GPL(atmel_tc_free);
81
82#if defined(CONFIG_OF)
83static struct atmel_tcb_config tcb_rm9200_config = {
84 .counter_width = 16,
85};
86
87static struct atmel_tcb_config tcb_sam9x5_config = {
88 .counter_width = 32,
89};
90
91static const struct of_device_id atmel_tcb_dt_ids[] = {
92 {
93 .compatible = "atmel,at91rm9200-tcb",
94 .data = &tcb_rm9200_config,
95 }, {
96 .compatible = "atmel,at91sam9x5-tcb",
97 .data = &tcb_sam9x5_config,
98 }, {
99 /* sentinel */
100 }
101};
102
103MODULE_DEVICE_TABLE(of, atmel_tcb_dt_ids);
104#endif
105
106static int __init tc_probe(struct platform_device *pdev)
107{
108 struct atmel_tc *tc;
109 struct clk *clk;
110 int irq;
111 struct resource *r;
112 unsigned int i;
113
114 irq = platform_get_irq(pdev, 0);
115 if (irq < 0)
116 return -EINVAL;
117
118 tc = devm_kzalloc(&pdev->dev, sizeof(struct atmel_tc), GFP_KERNEL);
119 if (!tc)
120 return -ENOMEM;
121
122 tc->pdev = pdev;
123
124 clk = devm_clk_get(&pdev->dev, "t0_clk");
125 if (IS_ERR(clk))
126 return PTR_ERR(clk);
127
128 tc->slow_clk = devm_clk_get(&pdev->dev, "slow_clk");
129 if (IS_ERR(tc->slow_clk))
130 return PTR_ERR(tc->slow_clk);
131
132 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
133 tc->regs = devm_ioremap_resource(&pdev->dev, r);
134 if (IS_ERR(tc->regs))
135 return PTR_ERR(tc->regs);
136
137 /* Now take SoC information if available */
138 if (pdev->dev.of_node) {
139 const struct of_device_id *match;
140 match = of_match_node(atmel_tcb_dt_ids, pdev->dev.of_node);
141 if (match)
142 tc->tcb_config = match->data;
143
144 tc->id = of_alias_get_id(tc->pdev->dev.of_node, "tcb");
145 } else {
146 tc->id = pdev->id;
147 }
148
149 tc->clk[0] = clk;
150 tc->clk[1] = devm_clk_get(&pdev->dev, "t1_clk");
151 if (IS_ERR(tc->clk[1]))
152 tc->clk[1] = clk;
153 tc->clk[2] = devm_clk_get(&pdev->dev, "t2_clk");
154 if (IS_ERR(tc->clk[2]))
155 tc->clk[2] = clk;
156
157 tc->irq[0] = irq;
158 tc->irq[1] = platform_get_irq(pdev, 1);
159 if (tc->irq[1] < 0)
160 tc->irq[1] = irq;
161 tc->irq[2] = platform_get_irq(pdev, 2);
162 if (tc->irq[2] < 0)
163 tc->irq[2] = irq;
164
165 for (i = 0; i < 3; i++)
166 writel(ATMEL_TC_ALL_IRQ, tc->regs + ATMEL_TC_REG(i, IDR));
167
168 spin_lock(&tc_list_lock);
169 list_add_tail(&tc->node, &tc_list);
170 spin_unlock(&tc_list_lock);
171
172 platform_set_drvdata(pdev, tc);
173
174 return 0;
175}
176
177static void tc_shutdown(struct platform_device *pdev)
178{
179 int i;
180 struct atmel_tc *tc = platform_get_drvdata(pdev);
181
182 for (i = 0; i < 3; i++)
183 writel(ATMEL_TC_ALL_IRQ, tc->regs + ATMEL_TC_REG(i, IDR));
184}
185
186static struct platform_driver tc_driver = {
187 .driver = {
188 .name = "atmel_tcb",
189 .of_match_table = of_match_ptr(atmel_tcb_dt_ids),
190 },
191 .shutdown = tc_shutdown,
192};
193
194static int __init tc_init(void)
195{
196 return platform_driver_probe(&tc_driver, tc_probe);
197}
198arch_initcall(tc_init);