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/*
* Copyright (c) 2012-2016 Zhang, Keguang <keguang.zhang@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#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);
}
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