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
  38 static int sun6i_a31_apb0_gates_clk_probe(struct platform_device *pdev)
  39 {
  40         struct device_node *np = pdev->dev.of_node;
  41         struct clk_onecell_data *clk_data;
  42         const struct of_device_id *device;
  43         const struct gates_data *data;
  44         const char *clk_parent;
  45         const char *clk_name;
  46         struct resource *r;
  47         void __iomem *reg;
  48         int ngates;
  49         int i;
  50         int j = 0;
  51
  52         if (!np)
  53                 return -ENODEV;
  54
  55         device = of_match_device(sun6i_a31_apb0_gates_clk_dt_ids, &pdev->dev);
  56         if (!device)
  57                 return -ENODEV;
  58         data = device->data;
  59
  60         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  61         reg = devm_ioremap_resource(&pdev->dev, r);
  62         if (IS_ERR(reg))
  63                 return PTR_ERR(reg);
  64
  65         clk_parent = of_clk_get_parent_name(np, 0);
  66         if (!clk_parent)
  67                 return -EINVAL;
  68
  69         clk_data = devm_kzalloc(&pdev->dev, sizeof(struct clk_onecell_data),
  70                                 GFP_KERNEL);
  71         if (!clk_data)
  72                 return -ENOMEM;
  73
  74         /* Worst-case size approximation and memory allocation */
  75         ngates = find_last_bit(data->mask, SUN6I_APB0_GATES_MAX_SIZE);
  76         clk_data->clks = devm_kcalloc(&pdev->dev, (ngates + 1),
  77                                       sizeof(struct clk *), GFP_KERNEL);
  78         if (!clk_data->clks)
  79                 return -ENOMEM;
  80
  81         for_each_set_bit(i, data->mask, SUN6I_APB0_GATES_MAX_SIZE) {
  82                 of_property_read_string_index(np, "clock-output-names",
  83                                               j, &clk_name);
  84
  85                 clk_data->clks[i] = clk_register_gate(&pdev->dev, clk_name,
  86                                                       clk_parent, 0, reg, i,
  87                                                       0, NULL);
  88                 WARN_ON(IS_ERR(clk_data->clks[i]));
  89                 clk_register_clkdev(clk_data->clks[i], clk_name, NULL);
  90
  91                 j++;
  92         }
  93
  94         clk_data->clk_num = ngates + 1;
  95
  96         return of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
  97 }
  98
  99 static struct platform_driver sun6i_a31_apb0_gates_clk_driver = {
 100         .driver = {
 101                 .name = "sun6i-a31-apb0-gates-clk",
 102                 .of_match_table = sun6i_a31_apb0_gates_clk_dt_ids,
 103         },
 104         .probe = sun6i_a31_apb0_gates_clk_probe,
 105 };
 106 module_platform_driver(sun6i_a31_apb0_gates_clk_driver);
 107
 108 MODULE_AUTHOR("Boris BREZILLON <boris.brezillon@free-electrons.com>");
 109 MODULE_DESCRIPTION("Allwinner A31 APB0 gate clocks driver");
 110 MODULE_LICENSE("GPL v2");