kernel/drivers/clk/sunxi/clk-sun8i-apb0.c

   1 /*
   2  * Copyright (C) 2014 Chen-Yu Tsai
   3  * Author: Chen-Yu Tsai <wens@csie.org>
   4  *
   5  * Allwinner A23 APB0 clock driver
   6  *
   7  * License Terms: GNU General Public License v2
   8  *
   9  * Based on clk-sun6i-apb0.c
  10  * Allwinner A31 APB0 clock driver
  11  *
  12  * Copyright (C) 2014 Free Electrons
  13  * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
  14  *
  15  */
  16
  17 #include <linux/clk-provider.h>
  18 #include <linux/module.h>
  19 #include <linux/of.h>
  20 #include <linux/platform_device.h>
  21
  22 static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
  23 {
  24         struct device_node *np = pdev->dev.of_node;
  25         const char *clk_name = np->name;
  26         const char *clk_parent;
  27         struct resource *r;
  28         void __iomem *reg;
  29         struct clk *clk;
  30
  31         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  32         reg = devm_ioremap_resource(&pdev->dev, r);
  33         if (IS_ERR(reg))
  34                 return PTR_ERR(reg);
  35
  36         clk_parent = of_clk_get_parent_name(np, 0);
  37         if (!clk_parent)
  38                 return -EINVAL;
  39
  40         of_property_read_string(np, "clock-output-names", &clk_name);
  41
  42         /* The A23 APB0 clock is a standard 2 bit wide divider clock */
  43         clk = clk_register_divider(&pdev->dev, clk_name, clk_parent, 0, reg,
  44                                    0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
  45         if (IS_ERR(clk))
  46                 return PTR_ERR(clk);
  47
  48         return of_clk_add_provider(np, of_clk_src_simple_get, clk);
  49 }
  50
  51 static const struct of_device_id sun8i_a23_apb0_clk_dt_ids[] = {
  52         { .compatible = "allwinner,sun8i-a23-apb0-clk" },
  53         { /* sentinel */ }
  54 };
  55
  56 static struct platform_driver sun8i_a23_apb0_clk_driver = {
  57         .driver = {
  58                 .name = "sun8i-a23-apb0-clk",
  59                 .of_match_table = sun8i_a23_apb0_clk_dt_ids,
  60         },
  61         .probe = sun8i_a23_apb0_clk_probe,
  62 };
  63 module_platform_driver(sun8i_a23_apb0_clk_driver);
  64
  65 MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
  66 MODULE_DESCRIPTION("Allwinner A23 APB0 clock Driver");
  67 MODULE_LICENSE("GPL v2");