linux/drivers/clk/clk-ls1x.c
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   1/*
   2 * Copyright (c) 2012 Zhang, Keguang <keguang.zhang@gmail.com>
   3 *
   4 * This program is free software; you can redistribute  it and/or modify it
   5 * under  the terms of  the GNU General  Public License as published by the
   6 * Free Software Foundation;  either version 2 of the  License, or (at your
   7 * option) any later version.
   8 */
   9
  10#include <linux/clkdev.h>
  11#include <linux/clk-provider.h>
  12#include <linux/io.h>
  13#include <linux/slab.h>
  14#include <linux/err.h>
  15
  16#include <loongson1.h>
  17
  18#define OSC     33
  19
  20static DEFINE_SPINLOCK(_lock);
  21
  22static int ls1x_pll_clk_enable(struct clk_hw *hw)
  23{
  24        return 0;
  25}
  26
  27static void ls1x_pll_clk_disable(struct clk_hw *hw)
  28{
  29}
  30
  31static unsigned long ls1x_pll_recalc_rate(struct clk_hw *hw,
  32                                             unsigned long parent_rate)
  33{
  34        u32 pll, rate;
  35
  36        pll = __raw_readl(LS1X_CLK_PLL_FREQ);
  37        rate = ((12 + (pll & 0x3f)) * 1000000) +
  38                ((((pll >> 8) & 0x3ff) * 1000000) >> 10);
  39        rate *= OSC;
  40        rate >>= 1;
  41
  42        return rate;
  43}
  44
  45static const struct clk_ops ls1x_pll_clk_ops = {
  46        .enable = ls1x_pll_clk_enable,
  47        .disable = ls1x_pll_clk_disable,
  48        .recalc_rate = ls1x_pll_recalc_rate,
  49};
  50
  51static struct clk * __init clk_register_pll(struct device *dev,
  52         const char *name, const char *parent_name, unsigned long flags)
  53{
  54        struct clk_hw *hw;
  55        struct clk *clk;
  56        struct clk_init_data init;
  57
  58        /* allocate the divider */
  59        hw = kzalloc(sizeof(struct clk_hw), GFP_KERNEL);
  60        if (!hw) {
  61                pr_err("%s: could not allocate clk_hw\n", __func__);
  62                return ERR_PTR(-ENOMEM);
  63        }
  64
  65        init.name = name;
  66        init.ops = &ls1x_pll_clk_ops;
  67        init.flags = flags | CLK_IS_BASIC;
  68        init.parent_names = (parent_name ? &parent_name : NULL);
  69        init.num_parents = (parent_name ? 1 : 0);
  70        hw->init = &init;
  71
  72        /* register the clock */
  73        clk = clk_register(dev, hw);
  74
  75        if (IS_ERR(clk))
  76                kfree(hw);
  77
  78        return clk;
  79}
  80
  81void __init ls1x_clk_init(void)
  82{
  83        struct clk *clk;
  84
  85        clk = clk_register_pll(NULL, "pll_clk", NULL, CLK_IS_ROOT);
  86        clk_prepare_enable(clk);
  87
  88        clk = clk_register_divider(NULL, "cpu_clk", "pll_clk",
  89                        CLK_SET_RATE_PARENT, LS1X_CLK_PLL_DIV, DIV_CPU_SHIFT,
  90                        DIV_CPU_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
  91        clk_prepare_enable(clk);
  92        clk_register_clkdev(clk, "cpu", NULL);
  93
  94        clk = clk_register_divider(NULL, "dc_clk", "pll_clk",
  95                        CLK_SET_RATE_PARENT, LS1X_CLK_PLL_DIV, DIV_DC_SHIFT,
  96                        DIV_DC_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
  97        clk_prepare_enable(clk);
  98        clk_register_clkdev(clk, "dc", NULL);
  99
 100        clk = clk_register_divider(NULL, "ahb_clk", "pll_clk",
 101                        CLK_SET_RATE_PARENT, LS1X_CLK_PLL_DIV, DIV_DDR_SHIFT,
 102                        DIV_DDR_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
 103        clk_prepare_enable(clk);
 104        clk_register_clkdev(clk, "ahb", NULL);
 105        clk_register_clkdev(clk, "stmmaceth", NULL);
 106
 107        clk = clk_register_fixed_factor(NULL, "apb_clk", "ahb_clk", 0, 1, 2);
 108        clk_prepare_enable(clk);
 109        clk_register_clkdev(clk, "apb", NULL);
 110        clk_register_clkdev(clk, "serial8250", NULL);
 111}
 112
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