LXR linux/drivers/clk/h8300/clk-div.c

   1/*
   2 * H8/300 divide clock driver
   3 *
   4 * Copyright 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
   5 */
   6
   7#include <linux/clk-provider.h>
   8#include <linux/err.h>
   9#include <linux/of.h>
  10#include <linux/of_address.h>
  11
  12static DEFINE_SPINLOCK(clklock);
  13
  14static void __init h8300_div_clk_setup(struct device_node *node)
  15{
  16        unsigned int num_parents;
  17        struct clk_hw *hw;
  18        const char *clk_name = node->name;
  19        const char *parent_name;
  20        void __iomem *divcr = NULL;
  21        int width;
  22        int offset;
  23
  24        num_parents = of_clk_get_parent_count(node);
  25        if (!num_parents) {
  26                pr_err("%s: no parent found", clk_name);
  27                return;
  28        }
  29
  30        divcr = of_iomap(node, 0);
  31        if (divcr == NULL) {
  32                pr_err("%s: failed to map divide register", clk_name);
  33                goto error;
  34        }
  35        offset = (unsigned long)divcr & 3;
  36        offset = (3 - offset) * 8;
  37        divcr = (void __iomem *)((unsigned long)divcr & ~3);
  38
  39        parent_name = of_clk_get_parent_name(node, 0);
  40        of_property_read_u32(node, "renesas,width", &width);
  41        hw = clk_hw_register_divider(NULL, clk_name, parent_name,
  42                                   CLK_SET_RATE_GATE, divcr, offset, width,
  43                                   CLK_DIVIDER_POWER_OF_TWO, &clklock);
  44        if (!IS_ERR(hw)) {
  45                of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
  46                return;
  47        }
  48        pr_err("%s: failed to register %s div clock (%ld)\n",
  49               __func__, clk_name, PTR_ERR(hw));
  50error:
  51        if (divcr)
  52                iounmap(divcr);
  53}
  54
  55CLK_OF_DECLARE(h8300_div_clk, "renesas,h8300-div-clock", h8300_div_clk_setup);
  56