kernel/drivers/clk/sunxi/clk-sun6i-apb0-gates.c

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