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

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * H8/300 divide clock driver
   4 *
   5 * Copyright 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
   6 */
   7
   8#include <linux/clk-provider.h>
   9#include <linux/err.h>
  10#include <linux/io.h>
  11#include <linux/of.h>
  12#include <linux/of_address.h>
  13
  14static DEFINE_SPINLOCK(clklock);
  15
  16static void __init h8300_div_clk_setup(struct device_node *node)
  17{
  18        unsigned int num_parents;
  19        struct clk_hw *hw;
  20        const char *clk_name = node->name;
  21        const char *parent_name;
  22        void __iomem *divcr = NULL;
  23        int width;
  24        int offset;
  25
  26        num_parents = of_clk_get_parent_count(node);
  27        if (!num_parents) {
  28                pr_err("%s: no parent found\n", clk_name);
  29                return;
  30        }
  31
  32        divcr = of_iomap(node, 0);
  33        if (divcr == NULL) {
  34                pr_err("%s: failed to map divide register\n", clk_name);
  35                goto error;
  36        }
  37        offset = (unsigned long)divcr & 3;
  38        offset = (3 - offset) * 8;
  39        divcr = (void __iomem *)((unsigned long)divcr & ~3);
  40
  41        parent_name = of_clk_get_parent_name(node, 0);
  42        of_property_read_u32(node, "renesas,width", &width);
  43        hw = clk_hw_register_divider(NULL, clk_name, parent_name,
  44                                   CLK_SET_RATE_GATE, divcr, offset, width,
  45                                   CLK_DIVIDER_POWER_OF_TWO, &clklock);
  46        if (!IS_ERR(hw)) {
  47                of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
  48                return;
  49        }
  50        pr_err("%s: failed to register %s div clock (%ld)\n",
  51               __func__, clk_name, PTR_ERR(hw));
  52error:
  53        if (divcr)
  54                iounmap(divcr);
  55}
  56
  57CLK_OF_DECLARE(h8300_div_clk, "renesas,h8300-div-clock", h8300_div_clk_setup);
  58