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	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
129	tc->regs = devm_ioremap_resource(&pdev->dev, r);
130	if (IS_ERR(tc->regs))
131		return PTR_ERR(tc->regs);
132
133	/* Now take SoC information if available */
134	if (pdev->dev.of_node) {
135		const struct of_device_id *match;
136		match = of_match_node(atmel_tcb_dt_ids, pdev->dev.of_node);
137		if (match)
138			tc->tcb_config = match->data;
139
140		tc->id = of_alias_get_id(tc->pdev->dev.of_node, "tcb");
141	} else {
142		tc->id = pdev->id;
143	}
144
145	tc->clk[0] = clk;
146	tc->clk[1] = devm_clk_get(&pdev->dev, "t1_clk");
147	if (IS_ERR(tc->clk[1]))
148		tc->clk[1] = clk;
149	tc->clk[2] = devm_clk_get(&pdev->dev, "t2_clk");
150	if (IS_ERR(tc->clk[2]))
151		tc->clk[2] = clk;
152
153	tc->irq[0] = irq;
154	tc->irq[1] = platform_get_irq(pdev, 1);
155	if (tc->irq[1] < 0)
156		tc->irq[1] = irq;
157	tc->irq[2] = platform_get_irq(pdev, 2);
158	if (tc->irq[2] < 0)
159		tc->irq[2] = irq;
160
161	for (i = 0; i < 3; i++)
162		writel(ATMEL_TC_ALL_IRQ, tc->regs + ATMEL_TC_REG(i, IDR));
163
164	spin_lock(&tc_list_lock);
165	list_add_tail(&tc->node, &tc_list);
166	spin_unlock(&tc_list_lock);
167
168	platform_set_drvdata(pdev, tc);
169
170	return 0;
171}
172
173static void tc_shutdown(struct platform_device *pdev)
174{
175	int i;
176	struct atmel_tc *tc = platform_get_drvdata(pdev);
177
178	for (i = 0; i < 3; i++)
179		writel(ATMEL_TC_ALL_IRQ, tc->regs + ATMEL_TC_REG(i, IDR));
180}
181
182static struct platform_driver tc_driver = {
183	.driver = {
184		.name	= "atmel_tcb",
185		.of_match_table	= of_match_ptr(atmel_tcb_dt_ids),
186	},
187	.shutdown = tc_shutdown,
188};
189
190static int __init tc_init(void)
191{
192	return platform_driver_probe(&tc_driver, tc_probe);
193}
194arch_initcall(tc_init);
195