drivers/clk/loongson1/clk-loongson1c.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com>
   4  */
   5
   6 #include <linux/clkdev.h>
   7 #include <linux/clk-provider.h>
   8 #include <linux/io.h>
   9
  10 #include <loongson1.h>
  11 #include "clk.h"
  12
  13 #define OSC             (24 * 1000000)
  14 #define DIV_APB         1
  15
  16 static DEFINE_SPINLOCK(_lock);
  17
  18 static unsigned long ls1x_pll_recalc_rate(struct clk_hw *hw,
  19                                           unsigned long parent_rate)
  20 {
  21         u32 pll, rate;
  22
  23         pll = __raw_readl(LS1X_CLK_PLL_FREQ);
  24         rate = ((pll >> 8) & 0xff) + ((pll >> 16) & 0xff);
  25         rate *= OSC;
  26         rate >>= 2;
  27
  28         return rate;
  29 }
  30
  31 static const struct clk_ops ls1x_pll_clk_ops = {
  32         .recalc_rate = ls1x_pll_recalc_rate,
  33 };
  34
  35 static const struct clk_div_table ahb_div_table[] = {
  36         [0] = { .val = 0, .div = 2 },
  37         [1] = { .val = 1, .div = 4 },
  38         [2] = { .val = 2, .div = 3 },
  39         [3] = { .val = 3, .div = 3 },
  40 };
  41
  42 void __init ls1x_clk_init(void)
  43 {
  44         struct clk_hw *hw;
  45
  46         hw = clk_hw_register_fixed_rate(NULL, "osc_clk", NULL, 0, OSC);
  47         clk_hw_register_clkdev(hw, "osc_clk", NULL);
  48
  49         /* clock derived from 24 MHz OSC clk */
  50         hw = clk_hw_register_pll(NULL, "pll_clk", "osc_clk",
  51                                 &ls1x_pll_clk_ops, 0);
  52         clk_hw_register_clkdev(hw, "pll_clk", NULL);
  53
  54         hw = clk_hw_register_divider(NULL, "cpu_clk_div", "pll_clk",
  55                                    CLK_GET_RATE_NOCACHE, LS1X_CLK_PLL_DIV,
  56                                    DIV_CPU_SHIFT, DIV_CPU_WIDTH,
  57                                    CLK_DIVIDER_ONE_BASED |
  58                                    CLK_DIVIDER_ROUND_CLOSEST, &_lock);
  59         clk_hw_register_clkdev(hw, "cpu_clk_div", NULL);
  60         hw = clk_hw_register_fixed_factor(NULL, "cpu_clk", "cpu_clk_div",
  61                                         0, 1, 1);
  62         clk_hw_register_clkdev(hw, "cpu_clk", NULL);
  63
  64         hw = clk_hw_register_divider(NULL, "dc_clk_div", "pll_clk",
  65                                    0, LS1X_CLK_PLL_DIV, DIV_DC_SHIFT,
  66                                    DIV_DC_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
  67         clk_hw_register_clkdev(hw, "dc_clk_div", NULL);
  68         hw = clk_hw_register_fixed_factor(NULL, "dc_clk", "dc_clk_div",
  69                                         0, 1, 1);
  70         clk_hw_register_clkdev(hw, "dc_clk", NULL);
  71
  72         hw = clk_hw_register_divider_table(NULL, "ahb_clk_div", "cpu_clk_div",
  73                                 0, LS1X_CLK_PLL_FREQ, DIV_DDR_SHIFT,
  74                                 DIV_DDR_WIDTH, CLK_DIVIDER_ALLOW_ZERO,
  75                                 ahb_div_table, &_lock);
  76         clk_hw_register_clkdev(hw, "ahb_clk_div", NULL);
  77         hw = clk_hw_register_fixed_factor(NULL, "ahb_clk", "ahb_clk_div",
  78                                         0, 1, 1);
  79         clk_hw_register_clkdev(hw, "ahb_clk", NULL);
  80         clk_hw_register_clkdev(hw, "ls1x-dma", NULL);
  81         clk_hw_register_clkdev(hw, "stmmaceth", NULL);
  82
  83         /* clock derived from AHB clk */
  84         hw = clk_hw_register_fixed_factor(NULL, "apb_clk", "ahb_clk", 0, 1,
  85                                         DIV_APB);
  86         clk_hw_register_clkdev(hw, "apb_clk", NULL);
  87         clk_hw_register_clkdev(hw, "ls1x-ac97", NULL);
  88         clk_hw_register_clkdev(hw, "ls1x-i2c", NULL);
  89         clk_hw_register_clkdev(hw, "ls1x-nand", NULL);
  90         clk_hw_register_clkdev(hw, "ls1x-pwmtimer", NULL);
  91         clk_hw_register_clkdev(hw, "ls1x-spi", NULL);
  92         clk_hw_register_clkdev(hw, "ls1x-wdt", NULL);
  93         clk_hw_register_clkdev(hw, "serial8250", NULL);
  94 }