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kernel/linux-rt-4.4.41/drivers/clk/sunxi/clk-sun6i-apb0.c 1.98 KB
5113f6f70   김현기   kernel add
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  /*
   * Copyright (C) 2014 Free Electrons
   *
   * License Terms: GNU General Public License v2
   * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
   *
   * Allwinner A31 APB0 clock driver
   *
   */
  
  #include <linux/clk-provider.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/platform_device.h>
  
  /*
   * The APB0 clk has a configurable divisor.
   *
   * We must use a clk_div_table and not a regular power of 2
   * divisor here, because the first 2 values divide the clock
   * by 2.
   */
  static const struct clk_div_table sun6i_a31_apb0_divs[] = {
  	{ .val = 0, .div = 2, },
  	{ .val = 1, .div = 2, },
  	{ .val = 2, .div = 4, },
  	{ .val = 3, .div = 8, },
  	{ /* sentinel */ },
  };
  
  static int sun6i_a31_apb0_clk_probe(struct platform_device *pdev)
  {
  	struct device_node *np = pdev->dev.of_node;
  	const char *clk_name = np->name;
  	const char *clk_parent;
  	struct resource *r;
  	void __iomem *reg;
  	struct clk *clk;
  
  	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;
  
  	of_property_read_string(np, "clock-output-names", &clk_name);
  
  	clk = clk_register_divider_table(&pdev->dev, clk_name, clk_parent,
  					 0, reg, 0, 2, 0, sun6i_a31_apb0_divs,
  					 NULL);
  	if (IS_ERR(clk))
  		return PTR_ERR(clk);
  
  	return of_clk_add_provider(np, of_clk_src_simple_get, clk);
  }
  
  static const struct of_device_id sun6i_a31_apb0_clk_dt_ids[] = {
  	{ .compatible = "allwinner,sun6i-a31-apb0-clk" },
  	{ /* sentinel */ }
  };
  MODULE_DEVICE_TABLE(of, sun6i_a31_apb0_clk_dt_ids);
  
  static struct platform_driver sun6i_a31_apb0_clk_driver = {
  	.driver = {
  		.name = "sun6i-a31-apb0-clk",
  		.of_match_table = sun6i_a31_apb0_clk_dt_ids,
  	},
  	.probe = sun6i_a31_apb0_clk_probe,
  };
  module_platform_driver(sun6i_a31_apb0_clk_driver);
  
  MODULE_AUTHOR("Boris BREZILLON <boris.brezillon@free-electrons.com>");
  MODULE_DESCRIPTION("Allwinner A31 APB0 clock Driver");
  MODULE_LICENSE("GPL v2");