Blame view

kernel/linux-rt-4.4.41/drivers/clk/sunxi/clk-sun6i-apb0-gates.c 2.95 KB
5113f6f70   김현기   kernel add
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
  /*
   * Copyright (C) 2014 Free Electrons
   *
   * License Terms: GNU General Public License v2
   * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
   *
   * Allwinner A31 APB0 clock gates driver
   *
   */
  
  #include <linux/clk-provider.h>
  #include <linux/clkdev.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/of_device.h>
  #include <linux/platform_device.h>
  
  #define SUN6I_APB0_GATES_MAX_SIZE	32
  
  struct gates_data {
  	DECLARE_BITMAP(mask, SUN6I_APB0_GATES_MAX_SIZE);
  };
  
  static const struct gates_data sun6i_a31_apb0_gates __initconst = {
  	.mask = {0x7F},
  };
  
  static const struct gates_data sun8i_a23_apb0_gates __initconst = {
  	.mask = {0x5D},
  };
  
  static const struct of_device_id sun6i_a31_apb0_gates_clk_dt_ids[] = {
  	{ .compatible = "allwinner,sun6i-a31-apb0-gates-clk", .data = &sun6i_a31_apb0_gates },
  	{ .compatible = "allwinner,sun8i-a23-apb0-gates-clk", .data = &sun8i_a23_apb0_gates },
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(of, sun6i_a31_apb0_gates_clk_dt_ids);
  
  static int sun6i_a31_apb0_gates_clk_probe(struct platform_device *pdev)
  {
  	struct device_node *np = pdev->dev.of_node;
  	struct clk_onecell_data *clk_data;
  	const struct of_device_id *device;
  	const struct gates_data *data;
  	const char *clk_parent;
  	const char *clk_name;
  	struct resource *r;
  	void __iomem *reg;
  	int ngates;
  	int i;
  	int j = 0;
  
  	if (!np)
  		return -ENODEV;
  
  	device = of_match_device(sun6i_a31_apb0_gates_clk_dt_ids, &pdev->dev);
  	if (!device)
  		return -ENODEV;
  	data = device->data;
  
  	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	reg = devm_ioremap_resource(&pdev->dev, r);
  	if (IS_ERR(reg))
  		return PTR_ERR(reg);
  
  	clk_parent = of_clk_get_parent_name(np, 0);
  	if (!clk_parent)
  		return -EINVAL;
  
  	clk_data = devm_kzalloc(&pdev->dev, sizeof(struct clk_onecell_data),
  				GFP_KERNEL);
  	if (!clk_data)
  		return -ENOMEM;
  
  	/* Worst-case size approximation and memory allocation */
  	ngates = find_last_bit(data->mask, SUN6I_APB0_GATES_MAX_SIZE);
  	clk_data->clks = devm_kcalloc(&pdev->dev, (ngates + 1),
  				      sizeof(struct clk *), GFP_KERNEL);
  	if (!clk_data->clks)
  		return -ENOMEM;
  
  	for_each_set_bit(i, data->mask, SUN6I_APB0_GATES_MAX_SIZE) {
  		of_property_read_string_index(np, "clock-output-names",
  					      j, &clk_name);
  
  		clk_data->clks[i] = clk_register_gate(&pdev->dev, clk_name,
  						      clk_parent, 0, reg, i,
  						      0, NULL);
  		WARN_ON(IS_ERR(clk_data->clks[i]));
  		clk_register_clkdev(clk_data->clks[i], clk_name, NULL);
  
  		j++;
  	}
  
  	clk_data->clk_num = ngates + 1;
  
  	return of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
  }
  
  static struct platform_driver sun6i_a31_apb0_gates_clk_driver = {
  	.driver = {
  		.name = "sun6i-a31-apb0-gates-clk",
  		.of_match_table = sun6i_a31_apb0_gates_clk_dt_ids,
  	},
  	.probe = sun6i_a31_apb0_gates_clk_probe,
  };
  module_platform_driver(sun6i_a31_apb0_gates_clk_driver);
  
  MODULE_AUTHOR("Boris BREZILLON <boris.brezillon@free-electrons.com>");
  MODULE_DESCRIPTION("Allwinner A31 APB0 gate clocks driver");
  MODULE_LICENSE("GPL v2");