/*
   * H8/300 divide clock driver
   *
   * Copyright 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
   */
  
  #include <linux/clk-provider.h>
  #include <linux/err.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  
  static DEFINE_SPINLOCK(clklock);
  
  static void __init h8300_div_clk_setup(struct device_node *node)
  {
  	int num_parents;
  	struct clk *clk;
  	const char *clk_name = node->name;
  	const char *parent_name;
  	void __iomem *divcr = NULL;
  	int width;
  	int offset;
  
  	num_parents = of_clk_get_parent_count(node);
  	if (num_parents < 1) {
  		pr_err("%s: no parent found", clk_name);
  		return;
  	}
  
  	divcr = of_iomap(node, 0);
  	if (divcr == NULL) {
  		pr_err("%s: failed to map divide register", clk_name);
  		goto error;
  	}
  	offset = (unsigned long)divcr & 3;
  	offset = (3 - offset) * 8;
  	divcr = (void *)((unsigned long)divcr & ~3);
  
  	parent_name = of_clk_get_parent_name(node, 0);
  	of_property_read_u32(node, "renesas,width", &width);
  	clk = clk_register_divider(NULL, clk_name, parent_name,
  				   CLK_SET_RATE_GATE, divcr, offset, width,
  				   CLK_DIVIDER_POWER_OF_TWO, &clklock);
  	if (!IS_ERR(clk)) {
  		of_clk_add_provider(node, of_clk_src_simple_get, clk);
  		return;
  	}
  	pr_err("%s: failed to register %s div clock (%ld)
  ",
  	       __func__, clk_name, PTR_ERR(clk));
  error:
  	if (divcr)
  		iounmap(divcr);
  }
  
  CLK_OF_DECLARE(h8300_div_clk, "renesas,h8300-div-clock", h8300_div_clk_setup);