drivers/clk/loongson1/clk-loongson1c.c

   1 /*
   2  * Copyright (c) 2016 Yang Ling <gnaygnil@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
  13 #include <loongson1.h>
  14 #include "clk.h"
  15
  16 #define OSC             (24 * 1000000)
  17 #define DIV_APB         1
  18
  19 static DEFINE_SPINLOCK(_lock);
  20
  21 static unsigned long ls1x_pll_recalc_rate(struct clk_hw *hw,
  22                                           unsigned long parent_rate)
  23 {
  24         u32 pll, rate;
  25
  26         pll = __raw_readl(LS1X_CLK_PLL_FREQ);
  27         rate = ((pll >> 8) & 0xff) + ((pll >> 16) & 0xff);
  28         rate *= OSC;
  29         rate >>= 2;
  30
  31         return rate;
  32 }
  33
  34 static const struct clk_ops ls1x_pll_clk_ops = {
  35         .recalc_rate = ls1x_pll_recalc_rate,
  36 };
  37
  38 static const struct clk_div_table ahb_div_table[] = {
  39         [0] = { .val = 0, .div = 2 },
  40         [1] = { .val = 1, .div = 4 },
  41         [2] = { .val = 2, .div = 3 },
  42         [3] = { .val = 3, .div = 3 },
  43 };
  44
  45 void __init ls1x_clk_init(void)
  46 {
  47         struct clk_hw *hw;
  48
  49         hw = clk_hw_register_fixed_rate(NULL, "osc_clk", NULL, 0, OSC);
  50         clk_hw_register_clkdev(hw, "osc_clk", NULL);
  51
  52         /* clock derived from 24 MHz OSC clk */
  53         hw = clk_hw_register_pll(NULL, "pll_clk", "osc_clk",
  54                                 &ls1x_pll_clk_ops, 0);
  55         clk_hw_register_clkdev(hw, "pll_clk", NULL);
  56
  57         hw = clk_hw_register_divider(NULL, "cpu_clk_div", "pll_clk",
  58                                    CLK_GET_RATE_NOCACHE, LS1X_CLK_PLL_DIV,
  59                                    DIV_CPU_SHIFT, DIV_CPU_WIDTH,
  60                                    CLK_DIVIDER_ONE_BASED |
  61                                    CLK_DIVIDER_ROUND_CLOSEST, &_lock);
  62         clk_hw_register_clkdev(hw, "cpu_clk_div", NULL);
  63         hw = clk_hw_register_fixed_factor(NULL, "cpu_clk", "cpu_clk_div",
  64                                         0, 1, 1);
  65         clk_hw_register_clkdev(hw, "cpu_clk", NULL);
  66
  67         hw = clk_hw_register_divider(NULL, "dc_clk_div", "pll_clk",
  68                                    0, LS1X_CLK_PLL_DIV, DIV_DC_SHIFT,
  69                                    DIV_DC_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
  70         clk_hw_register_clkdev(hw, "dc_clk_div", NULL);
  71         hw = clk_hw_register_fixed_factor(NULL, "dc_clk", "dc_clk_div",
  72                                         0, 1, 1);
  73         clk_hw_register_clkdev(hw, "dc_clk", NULL);
  74
  75         hw = clk_hw_register_divider_table(NULL, "ahb_clk_div", "cpu_clk_div",
  76                                 0, LS1X_CLK_PLL_FREQ, DIV_DDR_SHIFT,
  77                                 DIV_DDR_WIDTH, CLK_DIVIDER_ALLOW_ZERO,
  78                                 ahb_div_table, &_lock);
  79         clk_hw_register_clkdev(hw, "ahb_clk_div", NULL);
  80         hw = clk_hw_register_fixed_factor(NULL, "ahb_clk", "ahb_clk_div",
  81                                         0, 1, 1);
  82         clk_hw_register_clkdev(hw, "ahb_clk", NULL);
  83         clk_hw_register_clkdev(hw, "ls1x-dma", NULL);
  84         clk_hw_register_clkdev(hw, "stmmaceth", NULL);
  85
  86         /* clock derived from AHB clk */
  87         hw = clk_hw_register_fixed_factor(NULL, "apb_clk", "ahb_clk", 0, 1,
  88                                         DIV_APB);
  89         clk_hw_register_clkdev(hw, "apb_clk", NULL);
  90         clk_hw_register_clkdev(hw, "ls1x-ac97", NULL);
  91         clk_hw_register_clkdev(hw, "ls1x-i2c", NULL);
  92         clk_hw_register_clkdev(hw, "ls1x-nand", NULL);
  93         clk_hw_register_clkdev(hw, "ls1x-pwmtimer", NULL);
  94         clk_hw_register_clkdev(hw, "ls1x-spi", NULL);
  95         clk_hw_register_clkdev(hw, "ls1x-wdt", NULL);
  96         clk_hw_register_clkdev(hw, "serial8250", NULL);
  97 }