1 // SPDX-License-Identifier: GPL-2.0-only
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 #include <soc/at91/atmel_tcb.h>
14
15 /*
16 * This is a thin library to solve the problem of how to portably allocate
17 * one of the TC blocks. For simplicity, it doesn't currently expect to
18 * share individual timers between different drivers.
19 */
20
21 #if defined(CONFIG_AVR32)
22 /* AVR32 has these divide PBB */
23 const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
24 EXPORT_SYMBOL(atmel_tc_divisors);
25
26 #elif defined(CONFIG_ARCH_AT91)
27 /* AT91 has these divide MCK */
28 const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
29 EXPORT_SYMBOL(atmel_tc_divisors);
30
31 #endif
32
33 static DEFINE_SPINLOCK(tc_list_lock);
34 static LIST_HEAD(tc_list);
35
36 /**
37 * atmel_tc_alloc - allocate a specified TC block
38 * @block: which block to allocate
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 */
atmel_tc_alloc(unsigned block)44 struct atmel_tc *atmel_tc_alloc(unsigned block)
45 {
46 struct atmel_tc *tc;
47 struct platform_device *pdev = NULL;
48
49 spin_lock(&tc_list_lock);
50 list_for_each_entry(tc, &tc_list, node) {
51 if (tc->allocated)
52 continue;
53
54 if ((tc->pdev->dev.of_node && tc->id == block) ||
55 (tc->pdev->id == block)) {
56 pdev = tc->pdev;
57 tc->allocated = true;
58 break;
59 }
60 }
61 spin_unlock(&tc_list_lock);
62
63 return pdev ? tc : NULL;
64 }
65 EXPORT_SYMBOL_GPL(atmel_tc_alloc);
66
67 /**
68 * atmel_tc_free - release a specified TC block
69 * @tc: Timer/counter block that was returned by atmel_tc_alloc()
70 *
71 * This reverses the effect of atmel_tc_alloc(), invalidating the resource
72 * returned by that routine and making the TC available to other drivers.
73 */
atmel_tc_free(struct atmel_tc * tc)74 void atmel_tc_free(struct atmel_tc *tc)
75 {
76 spin_lock(&tc_list_lock);
77 if (tc->allocated)
78 tc->allocated = false;
79 spin_unlock(&tc_list_lock);
80 }
81 EXPORT_SYMBOL_GPL(atmel_tc_free);
82
83 #if defined(CONFIG_OF)
84 static struct atmel_tcb_config tcb_rm9200_config = {
85 .counter_width = 16,
86 };
87
88 static struct atmel_tcb_config tcb_sam9x5_config = {
89 .counter_width = 32,
90 };
91
92 static const struct of_device_id atmel_tcb_dt_ids[] = {
93 {
94 .compatible = "atmel,at91rm9200-tcb",
95 .data = &tcb_rm9200_config,
96 }, {
97 .compatible = "atmel,at91sam9x5-tcb",
98 .data = &tcb_sam9x5_config,
99 }, {
100 /* sentinel */
101 }
102 };
103
104 MODULE_DEVICE_TABLE(of, atmel_tcb_dt_ids);
105 #endif
106
tc_probe(struct platform_device * pdev)107 static int __init tc_probe(struct platform_device *pdev)
108 {
109 struct atmel_tc *tc;
110 struct clk *clk;
111 int irq;
112 struct resource *r;
113 unsigned int i;
114
115 if (of_get_child_count(pdev->dev.of_node))
116 return -EBUSY;
117
118 irq = platform_get_irq(pdev, 0);
119 if (irq < 0)
120 return -EINVAL;
121
122 tc = devm_kzalloc(&pdev->dev, sizeof(struct atmel_tc), GFP_KERNEL);
123 if (!tc)
124 return -ENOMEM;
125
126 tc->pdev = pdev;
127
128 clk = devm_clk_get(&pdev->dev, "t0_clk");
129 if (IS_ERR(clk))
130 return PTR_ERR(clk);
131
132 tc->slow_clk = devm_clk_get(&pdev->dev, "slow_clk");
133 if (IS_ERR(tc->slow_clk))
134 return PTR_ERR(tc->slow_clk);
135
136 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
137 tc->regs = devm_ioremap_resource(&pdev->dev, r);
138 if (IS_ERR(tc->regs))
139 return PTR_ERR(tc->regs);
140
141 /* Now take SoC information if available */
142 if (pdev->dev.of_node) {
143 const struct of_device_id *match;
144 match = of_match_node(atmel_tcb_dt_ids, pdev->dev.of_node);
145 if (match)
146 tc->tcb_config = match->data;
147
148 tc->id = of_alias_get_id(tc->pdev->dev.of_node, "tcb");
149 } else {
150 tc->id = pdev->id;
151 }
152
153 tc->clk[0] = clk;
154 tc->clk[1] = devm_clk_get(&pdev->dev, "t1_clk");
155 if (IS_ERR(tc->clk[1]))
156 tc->clk[1] = clk;
157 tc->clk[2] = devm_clk_get(&pdev->dev, "t2_clk");
158 if (IS_ERR(tc->clk[2]))
159 tc->clk[2] = clk;
160
161 tc->irq[0] = irq;
162 tc->irq[1] = platform_get_irq(pdev, 1);
163 if (tc->irq[1] < 0)
164 tc->irq[1] = irq;
165 tc->irq[2] = platform_get_irq(pdev, 2);
166 if (tc->irq[2] < 0)
167 tc->irq[2] = irq;
168
169 for (i = 0; i < 3; i++)
170 writel(ATMEL_TC_ALL_IRQ, tc->regs + ATMEL_TC_REG(i, IDR));
171
172 spin_lock(&tc_list_lock);
173 list_add_tail(&tc->node, &tc_list);
174 spin_unlock(&tc_list_lock);
175
176 platform_set_drvdata(pdev, tc);
177
178 return 0;
179 }
180
tc_shutdown(struct platform_device * pdev)181 static void tc_shutdown(struct platform_device *pdev)
182 {
183 int i;
184 struct atmel_tc *tc = platform_get_drvdata(pdev);
185
186 for (i = 0; i < 3; i++)
187 writel(ATMEL_TC_ALL_IRQ, tc->regs + ATMEL_TC_REG(i, IDR));
188 }
189
190 static struct platform_driver tc_driver = {
191 .driver = {
192 .name = "atmel_tcb",
193 .of_match_table = of_match_ptr(atmel_tcb_dt_ids),
194 },
195 .shutdown = tc_shutdown,
196 };
197
tc_init(void)198 static int __init tc_init(void)
199 {
200 return platform_driver_probe(&tc_driver, tc_probe);
201 }
202 arch_initcall(tc_init);
203
