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/init.h>
  13 #include <linux/of.h>
  14 #include <linux/of_device.h>
  15 #include <linux/platform_device.h>
  16
  17 #define SUN6I_APB0_GATES_MAX_SIZE       32
  18
  19 struct gates_data {
  20         DECLARE_BITMAP(mask, SUN6I_APB0_GATES_MAX_SIZE);
  21 };
  22
  23 static const struct gates_data sun6i_a31_apb0_gates __initconst = {
  24         .mask = {0x7F},
  25 };
  26
  27 static const struct gates_data sun8i_a23_apb0_gates __initconst = {
  28         .mask = {0x5D},
  29 };
  30
  31 static const struct of_device_id sun6i_a31_apb0_gates_clk_dt_ids[] = {
  32         { .compatible = "allwinner,sun6i-a31-apb0-gates-clk", .data = &sun6i_a31_apb0_gates },
  33         { .compatible = "allwinner,sun8i-a23-apb0-gates-clk", .data = &sun8i_a23_apb0_gates },
  34         { /* sentinel */ }
  35 };
  36
  37 static int sun6i_a31_apb0_gates_clk_probe(struct platform_device *pdev)
  38 {
  39         struct device_node *np = pdev->dev.of_node;
  40         struct clk_onecell_data *clk_data;
  41         const struct of_device_id *device;
  42         const struct gates_data *data;
  43         const char *clk_parent;
  44         const char *clk_name;
  45         struct resource *r;
  46         void __iomem *reg;
  47         int ngates;
  48         int i;
  49         int j = 0;
  50
  51         if (!np)
  52                 return -ENODEV;
  53
  54         device = of_match_device(sun6i_a31_apb0_gates_clk_dt_ids, &pdev->dev);
  55         if (!device)
  56                 return -ENODEV;
  57         data = device->data;
  58
  59         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  60         reg = devm_ioremap_resource(&pdev->dev, r);
  61         if (IS_ERR(reg))
  62                 return PTR_ERR(reg);
  63
  64         clk_parent = of_clk_get_parent_name(np, 0);
  65         if (!clk_parent)
  66                 return -EINVAL;
  67
  68         clk_data = devm_kzalloc(&pdev->dev, sizeof(struct clk_onecell_data),
  69                                 GFP_KERNEL);
  70         if (!clk_data)
  71                 return -ENOMEM;
  72
  73         /* Worst-case size approximation and memory allocation */
  74         ngates = find_last_bit(data->mask, SUN6I_APB0_GATES_MAX_SIZE);
  75         clk_data->clks = devm_kcalloc(&pdev->dev, (ngates + 1),
  76                                       sizeof(struct clk *), GFP_KERNEL);
  77         if (!clk_data->clks)
  78                 return -ENOMEM;
  79
  80         for_each_set_bit(i, data->mask, SUN6I_APB0_GATES_MAX_SIZE) {
  81                 of_property_read_string_index(np, "clock-output-names",
  82                                               j, &clk_name);
  83
  84                 clk_data->clks[i] = clk_register_gate(&pdev->dev, clk_name,
  85                                                       clk_parent, 0, reg, i,
  86                                                       0, NULL);
  87                 WARN_ON(IS_ERR(clk_data->clks[i]));
  88
  89                 j++;
  90         }
  91
  92         clk_data->clk_num = ngates + 1;
  93
  94         return of_clk_add_provider(np, of_clk_src_onecell_get, clk_data);
  95 }
  96
  97 static struct platform_driver sun6i_a31_apb0_gates_clk_driver = {
  98         .driver = {
  99                 .name = "sun6i-a31-apb0-gates-clk",
 100                 .of_match_table = sun6i_a31_apb0_gates_clk_dt_ids,
 101         },
 102         .probe = sun6i_a31_apb0_gates_clk_probe,
 103 };
 104 builtin_platform_driver(sun6i_a31_apb0_gates_clk_driver);