clk-ls1x.c
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/*
* Copyright (c) 2012 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/slab.h>
#include <linux/err.h>
#include <loongson1.h>
#define OSC (33 * 1000000)
#define DIV_APB 2
static DEFINE_SPINLOCK(_lock);
static int ls1x_pll_clk_enable(struct clk_hw *hw)
{
return 0;
}
static void ls1x_pll_clk_disable(struct clk_hw *hw)
{
}
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 & 0x3f) + (((pll >> 8) & 0x3ff) >> 10);
rate *= OSC;
rate >>= 1;
return rate;
}
static const struct clk_ops ls1x_pll_clk_ops = {
.enable = ls1x_pll_clk_enable,
.disable = ls1x_pll_clk_disable,
.recalc_rate = ls1x_pll_recalc_rate,
};
static struct clk *__init clk_register_pll(struct device *dev,
const char *name,
const char *parent_name,
unsigned long flags)
{
struct clk_hw *hw;
struct clk *clk;
struct clk_init_data init;
/* allocate the divider */
hw = kzalloc(sizeof(struct clk_hw), GFP_KERNEL);
if (!hw) {
pr_err("%s: could not allocate clk_hw\n", __func__);
return ERR_PTR(-ENOMEM);
}
init.name = name;
init.ops = &ls1x_pll_clk_ops;
init.flags = flags | CLK_IS_BASIC;
init.parent_names = (parent_name ? &parent_name : NULL);
init.num_parents = (parent_name ? 1 : 0);
hw->init = &init;
/* register the clock */
clk = clk_register(dev, hw);
if (IS_ERR(clk))
kfree(hw);
return clk;
}
static const char const *cpu_parents[] = { "cpu_clk_div", "osc_33m_clk", };
static const char const *ahb_parents[] = { "ahb_clk_div", "osc_33m_clk", };
static const char const *dc_parents[] = { "dc_clk_div", "osc_33m_clk", };
void __init ls1x_clk_init(void)
{
struct clk *clk;
clk = clk_register_fixed_rate(NULL, "osc_33m_clk", NULL, CLK_IS_ROOT,
OSC);
clk_register_clkdev(clk, "osc_33m_clk", NULL);
/* clock derived from 33 MHz OSC clk */
clk = clk_register_pll(NULL, "pll_clk", "osc_33m_clk", 0);
clk_register_clkdev(clk, "pll_clk", NULL);
/* clock derived from PLL clk */
/* _____
* _______________________| |
* OSC ___/ | MUX |___ CPU CLK
* \___ PLL ___ CPU DIV ___| |
* |_____|
*/
clk = clk_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_register_clkdev(clk, "cpu_clk_div", NULL);
clk = clk_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_register_clkdev(clk, "cpu_clk", NULL);
/* _____
* _______________________| |
* OSC ___/ | MUX |___ DC CLK
* \___ PLL ___ DC DIV ___| |
* |_____|
*/
clk = clk_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_register_clkdev(clk, "dc_clk_div", NULL);
clk = clk_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_register_clkdev(clk, "dc_clk", NULL);
/* _____
* _______________________| |
* OSC ___/ | MUX |___ DDR CLK
* \___ PLL ___ DDR DIV ___| |
* |_____|
*/
clk = clk_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_register_clkdev(clk, "ahb_clk_div", NULL);
clk = clk_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_register_clkdev(clk, "ahb_clk", NULL);
clk_register_clkdev(clk, "stmmaceth", NULL);
/* clock derived from AHB clk */
/* APB clk is always half of the AHB clk */
clk = clk_register_fixed_factor(NULL, "apb_clk", "ahb_clk", 0, 1,
DIV_APB);
clk_register_clkdev(clk, "apb_clk", NULL);
clk_register_clkdev(clk, "ls1x_i2c", NULL);
clk_register_clkdev(clk, "ls1x_pwmtimer", NULL);
clk_register_clkdev(clk, "ls1x_spi", NULL);
clk_register_clkdev(clk, "ls1x_wdt", NULL);
clk_register_clkdev(clk, "serial8250", NULL);
}