hc
2024-10-12 a5969cabbb4660eab42b6ef0412cbbd1200cf14d
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2012-2016 Zhang, Keguang <keguang.zhang@gmail.com>
 */
 
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/err.h>
 
#include <loongson1.h>
#include "clk.h"
 
#define OSC        (33 * 1000000)
#define DIV_APB        2
 
static DEFINE_SPINLOCK(_lock);
 
static unsigned long ls1x_pll_recalc_rate(struct clk_hw *hw,
                     unsigned long parent_rate)
{
   u32 pll, rate;
 
   pll = __raw_readl(LS1X_CLK_PLL_FREQ);
   rate = 12 + (pll & GENMASK(5, 0));
   rate *= OSC;
   rate >>= 1;
 
   return rate;
}
 
static const struct clk_ops ls1x_pll_clk_ops = {
   .recalc_rate = ls1x_pll_recalc_rate,
};
 
static const char *const cpu_parents[] = { "cpu_clk_div", "osc_clk", };
static const char *const ahb_parents[] = { "ahb_clk_div", "osc_clk", };
static const char *const dc_parents[] = { "dc_clk_div", "osc_clk", };
 
void __init ls1x_clk_init(void)
{
   struct clk_hw *hw;
 
   hw = clk_hw_register_fixed_rate(NULL, "osc_clk", NULL, 0, OSC);
   clk_hw_register_clkdev(hw, "osc_clk", NULL);
 
   /* clock derived from 33 MHz OSC clk */
   hw = clk_hw_register_pll(NULL, "pll_clk", "osc_clk",
                &ls1x_pll_clk_ops, 0);
   clk_hw_register_clkdev(hw, "pll_clk", NULL);
 
   /* clock derived from PLL clk */
   /*                                 _____
    *         _______________________|     |
    * OSC ___/                       | MUX |___ CPU CLK
    *        \___ PLL ___ CPU DIV ___|     |
    *                                |_____|
    */
   hw = clk_hw_register_divider(NULL, "cpu_clk_div", "pll_clk",
                  CLK_GET_RATE_NOCACHE, LS1X_CLK_PLL_DIV,
                  DIV_CPU_SHIFT, DIV_CPU_WIDTH,
                  CLK_DIVIDER_ONE_BASED |
                  CLK_DIVIDER_ROUND_CLOSEST, &_lock);
   clk_hw_register_clkdev(hw, "cpu_clk_div", NULL);
   hw = clk_hw_register_mux(NULL, "cpu_clk", cpu_parents,
                  ARRAY_SIZE(cpu_parents),
                  CLK_SET_RATE_NO_REPARENT, LS1X_CLK_PLL_DIV,
                  BYPASS_CPU_SHIFT, BYPASS_CPU_WIDTH, 0, &_lock);
   clk_hw_register_clkdev(hw, "cpu_clk", NULL);
 
   /*                                 _____
    *         _______________________|     |
    * OSC ___/                       | MUX |___ DC  CLK
    *        \___ PLL ___ DC  DIV ___|     |
    *                                |_____|
    */
   hw = clk_hw_register_divider(NULL, "dc_clk_div", "pll_clk",
                  0, LS1X_CLK_PLL_DIV, DIV_DC_SHIFT,
                  DIV_DC_WIDTH, CLK_DIVIDER_ONE_BASED, &_lock);
   clk_hw_register_clkdev(hw, "dc_clk_div", NULL);
   hw = clk_hw_register_mux(NULL, "dc_clk", dc_parents,
                  ARRAY_SIZE(dc_parents),
                  CLK_SET_RATE_NO_REPARENT, LS1X_CLK_PLL_DIV,
                  BYPASS_DC_SHIFT, BYPASS_DC_WIDTH, 0, &_lock);
   clk_hw_register_clkdev(hw, "dc_clk", NULL);
 
   /*                                 _____
    *         _______________________|     |
    * OSC ___/                       | MUX |___ DDR CLK
    *        \___ PLL ___ DDR DIV ___|     |
    *                                |_____|
    */
   hw = clk_hw_register_divider(NULL, "ahb_clk_div", "pll_clk",
                  0, LS1X_CLK_PLL_DIV, DIV_DDR_SHIFT,
                  DIV_DDR_WIDTH, CLK_DIVIDER_ONE_BASED,
                  &_lock);
   clk_hw_register_clkdev(hw, "ahb_clk_div", NULL);
   hw = clk_hw_register_mux(NULL, "ahb_clk", ahb_parents,
                  ARRAY_SIZE(ahb_parents),
                  CLK_SET_RATE_NO_REPARENT, LS1X_CLK_PLL_DIV,
                  BYPASS_DDR_SHIFT, BYPASS_DDR_WIDTH, 0, &_lock);
   clk_hw_register_clkdev(hw, "ahb_clk", NULL);
   clk_hw_register_clkdev(hw, "ls1x-dma", NULL);
   clk_hw_register_clkdev(hw, "stmmaceth", NULL);
 
   /* clock derived from AHB clk */
   /* APB clk is always half of the AHB clk */
   hw = clk_hw_register_fixed_factor(NULL, "apb_clk", "ahb_clk", 0, 1,
                   DIV_APB);
   clk_hw_register_clkdev(hw, "apb_clk", NULL);
   clk_hw_register_clkdev(hw, "ls1x-ac97", NULL);
   clk_hw_register_clkdev(hw, "ls1x-i2c", NULL);
   clk_hw_register_clkdev(hw, "ls1x-nand", NULL);
   clk_hw_register_clkdev(hw, "ls1x-pwmtimer", NULL);
   clk_hw_register_clkdev(hw, "ls1x-spi", NULL);
   clk_hw_register_clkdev(hw, "ls1x-wdt", NULL);
   clk_hw_register_clkdev(hw, "serial8250", NULL);
}