304 lines
		
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			304 lines
		
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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 * Clock driver for Loongson-1 SoC
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 *
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 * Copyright (C) 2012-2023 Keguang Zhang <keguang.zhang@gmail.com>
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 */
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#include <linux/bits.h>
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#include <linux/clk-provider.h>
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#include <linux/container_of.h>
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#include <linux/io.h>
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#include <linux/of_address.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/printk.h>
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#include <dt-bindings/clock/loongson,ls1x-clk.h>
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/* Loongson 1 Clock Register Definitions */
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#define CLK_PLL_FREQ		0x0
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#define CLK_PLL_DIV		0x4
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static DEFINE_SPINLOCK(ls1x_clk_div_lock);
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struct ls1x_clk_pll_data {
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	u32 fixed;
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	u8 shift;
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	u8 int_shift;
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	u8 int_width;
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	u8 frac_shift;
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	u8 frac_width;
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};
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struct ls1x_clk_div_data {
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	u8 shift;
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	u8 width;
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	unsigned long flags;
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	const struct clk_div_table *table;
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	u8 bypass_shift;
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	u8 bypass_inv;
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	spinlock_t *lock;	/* protect access to DIV registers */
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};
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struct ls1x_clk {
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	void __iomem *reg;
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	unsigned int offset;
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	struct clk_hw hw;
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	const void *data;
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};
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#define to_ls1x_clk(_hw) container_of(_hw, struct ls1x_clk, hw)
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static inline unsigned long ls1x_pll_rate_part(unsigned int val,
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					       unsigned int shift,
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					       unsigned int width)
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{
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	return (val & GENMASK(shift + width, shift)) >> shift;
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}
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static unsigned long ls1x_pll_recalc_rate(struct clk_hw *hw,
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					  unsigned long parent_rate)
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{
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	struct ls1x_clk *ls1x_clk = to_ls1x_clk(hw);
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	const struct ls1x_clk_pll_data *d = ls1x_clk->data;
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	u32 val, rate;
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	val = readl(ls1x_clk->reg);
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	rate = d->fixed;
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	rate += ls1x_pll_rate_part(val, d->int_shift, d->int_width);
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	if (d->frac_width)
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		rate += ls1x_pll_rate_part(val, d->frac_shift, d->frac_width);
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	rate *= parent_rate;
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	rate >>= d->shift;
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	return rate;
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}
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static const struct clk_ops ls1x_pll_clk_ops = {
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	.recalc_rate = ls1x_pll_recalc_rate,
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};
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static unsigned long ls1x_divider_recalc_rate(struct clk_hw *hw,
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					      unsigned long parent_rate)
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{
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	struct ls1x_clk *ls1x_clk = to_ls1x_clk(hw);
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	const struct ls1x_clk_div_data *d = ls1x_clk->data;
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	unsigned int val;
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	val = readl(ls1x_clk->reg) >> d->shift;
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	val &= clk_div_mask(d->width);
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	return divider_recalc_rate(hw, parent_rate, val, d->table,
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				   d->flags, d->width);
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}
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static long ls1x_divider_round_rate(struct clk_hw *hw, unsigned long rate,
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				    unsigned long *prate)
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{
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	struct ls1x_clk *ls1x_clk = to_ls1x_clk(hw);
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	const struct ls1x_clk_div_data *d = ls1x_clk->data;
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	return divider_round_rate(hw, rate, prate, d->table,
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				  d->width, d->flags);
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}
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static int ls1x_divider_set_rate(struct clk_hw *hw, unsigned long rate,
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				 unsigned long parent_rate)
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{
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	struct ls1x_clk *ls1x_clk = to_ls1x_clk(hw);
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	const struct ls1x_clk_div_data *d = ls1x_clk->data;
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	int val, div_val;
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	unsigned long flags = 0;
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	div_val = divider_get_val(rate, parent_rate, d->table,
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				  d->width, d->flags);
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	if (div_val < 0)
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		return div_val;
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	spin_lock_irqsave(d->lock, flags);
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	/* Bypass the clock */
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	val = readl(ls1x_clk->reg);
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	if (d->bypass_inv)
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		val &= ~BIT(d->bypass_shift);
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	else
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		val |= BIT(d->bypass_shift);
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	writel(val, ls1x_clk->reg);
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	val = readl(ls1x_clk->reg);
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	val &= ~(clk_div_mask(d->width) << d->shift);
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	val |= (u32)div_val << d->shift;
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	writel(val, ls1x_clk->reg);
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	/* Restore the clock */
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	val = readl(ls1x_clk->reg);
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	if (d->bypass_inv)
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		val |= BIT(d->bypass_shift);
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	else
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		val &= ~BIT(d->bypass_shift);
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	writel(val, ls1x_clk->reg);
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	spin_unlock_irqrestore(d->lock, flags);
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	return 0;
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}
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static const struct clk_ops ls1x_clk_divider_ops = {
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	.recalc_rate = ls1x_divider_recalc_rate,
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	.round_rate = ls1x_divider_round_rate,
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	.set_rate = ls1x_divider_set_rate,
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};
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#define LS1X_CLK_PLL(_name, _offset, _fixed, _shift,			\
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		     f_shift, f_width, i_shift, i_width)		\
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struct ls1x_clk _name = {						\
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	.offset = (_offset),						\
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	.data = &(const struct ls1x_clk_pll_data) {			\
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		.fixed = (_fixed),					\
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		.shift = (_shift),					\
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		.int_shift = (i_shift),					\
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		.int_width = (i_width),					\
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		.frac_shift = (f_shift),				\
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		.frac_width = (f_width),				\
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	},								\
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	.hw.init = &(const struct clk_init_data) {			\
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		.name = #_name,						\
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		.ops = &ls1x_pll_clk_ops,				\
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		.parent_data = &(const struct clk_parent_data) {	\
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			.fw_name = "xtal",				\
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			.name = "xtal",					\
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			.index = -1,					\
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		},							\
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		.num_parents = 1,					\
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	},								\
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}
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#define LS1X_CLK_DIV(_name, _pname, _offset, _shift, _width,		\
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		     _table, _bypass_shift, _bypass_inv, _flags)	\
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struct ls1x_clk _name = {						\
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	.offset = (_offset),						\
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	.data = &(const struct ls1x_clk_div_data){			\
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		.shift = (_shift),					\
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		.width = (_width),					\
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		.table = (_table),					\
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		.flags = (_flags),					\
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		.bypass_shift = (_bypass_shift),			\
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		.bypass_inv = (_bypass_inv),				\
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		.lock = &ls1x_clk_div_lock,				\
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	},								\
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	.hw.init = &(const struct clk_init_data) {			\
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		.name = #_name,						\
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		.ops = &ls1x_clk_divider_ops,				\
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		.parent_hws = (const struct clk_hw *[]) { _pname },	\
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		.num_parents = 1,					\
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		.flags = CLK_GET_RATE_NOCACHE,				\
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	},								\
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}
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static LS1X_CLK_PLL(ls1b_clk_pll, CLK_PLL_FREQ, 12, 1, 0, 5, 0, 0);
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static LS1X_CLK_DIV(ls1b_clk_cpu, &ls1b_clk_pll.hw, CLK_PLL_DIV,
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		    20, 4, NULL, 8, 0,
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		    CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ROUND_CLOSEST);
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static LS1X_CLK_DIV(ls1b_clk_dc, &ls1b_clk_pll.hw, CLK_PLL_DIV,
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		    26, 4, NULL, 12, 0, CLK_DIVIDER_ONE_BASED);
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static LS1X_CLK_DIV(ls1b_clk_ahb, &ls1b_clk_pll.hw, CLK_PLL_DIV,
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		    14, 4, NULL, 10, 0, CLK_DIVIDER_ONE_BASED);
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static CLK_FIXED_FACTOR(ls1b_clk_apb, "ls1b_clk_apb", "ls1b_clk_ahb", 2, 1,
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			CLK_SET_RATE_PARENT);
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static struct clk_hw_onecell_data ls1b_clk_hw_data = {
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	.hws = {
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		[LS1X_CLKID_PLL] = &ls1b_clk_pll.hw,
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		[LS1X_CLKID_CPU] = &ls1b_clk_cpu.hw,
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		[LS1X_CLKID_DC] = &ls1b_clk_dc.hw,
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		[LS1X_CLKID_AHB] = &ls1b_clk_ahb.hw,
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		[LS1X_CLKID_APB] = &ls1b_clk_apb.hw,
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	},
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	.num = CLK_NR_CLKS,
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};
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static const struct clk_div_table ls1c_ahb_div_table[] = {
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	[0] = { .val = 0, .div = 2 },
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	[1] = { .val = 1, .div = 4 },
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	[2] = { .val = 2, .div = 3 },
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	[3] = { .val = 3, .div = 3 },
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	[4] = { /* sentinel */ }
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};
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static LS1X_CLK_PLL(ls1c_clk_pll, CLK_PLL_FREQ, 0, 2, 8, 8, 16, 8);
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static LS1X_CLK_DIV(ls1c_clk_cpu, &ls1c_clk_pll.hw, CLK_PLL_DIV,
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		    8, 7, NULL, 0, 1,
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		    CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ROUND_CLOSEST);
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static LS1X_CLK_DIV(ls1c_clk_dc, &ls1c_clk_pll.hw, CLK_PLL_DIV,
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		    24, 7, NULL, 4, 1, CLK_DIVIDER_ONE_BASED);
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static LS1X_CLK_DIV(ls1c_clk_ahb, &ls1c_clk_cpu.hw, CLK_PLL_FREQ,
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		    0, 2, ls1c_ahb_div_table, 0, 0, CLK_DIVIDER_ALLOW_ZERO);
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static CLK_FIXED_FACTOR(ls1c_clk_apb, "ls1c_clk_apb", "ls1c_clk_ahb", 1, 1,
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			CLK_SET_RATE_PARENT);
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static struct clk_hw_onecell_data ls1c_clk_hw_data = {
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	.hws = {
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		[LS1X_CLKID_PLL] = &ls1c_clk_pll.hw,
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		[LS1X_CLKID_CPU] = &ls1c_clk_cpu.hw,
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		[LS1X_CLKID_DC] = &ls1c_clk_dc.hw,
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		[LS1X_CLKID_AHB] = &ls1c_clk_ahb.hw,
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		[LS1X_CLKID_APB] = &ls1c_clk_apb.hw,
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	},
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	.num = CLK_NR_CLKS,
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};
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static void __init ls1x_clk_init(struct device_node *np,
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				 struct clk_hw_onecell_data *hw_data)
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{
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	struct ls1x_clk *ls1x_clk;
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	void __iomem *reg;
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	int i, ret;
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	reg = of_iomap(np, 0);
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	if (!reg) {
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		pr_err("Unable to map base for %pOF\n", np);
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		return;
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	}
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	for (i = 0; i < hw_data->num; i++) {
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		/* array might be sparse */
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		if (!hw_data->hws[i])
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			continue;
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		if (i != LS1X_CLKID_APB) {
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			ls1x_clk = to_ls1x_clk(hw_data->hws[i]);
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			ls1x_clk->reg = reg + ls1x_clk->offset;
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		}
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		ret = of_clk_hw_register(np, hw_data->hws[i]);
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		if (ret)
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			goto err;
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	}
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	ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, hw_data);
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	if (!ret)
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		return;
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err:
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	pr_err("Failed to register %pOF\n", np);
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	while (--i >= 0)
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		clk_hw_unregister(hw_data->hws[i]);
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	iounmap(reg);
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}
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static void __init ls1b_clk_init(struct device_node *np)
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{
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	return ls1x_clk_init(np, &ls1b_clk_hw_data);
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}
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static void __init ls1c_clk_init(struct device_node *np)
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{
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	return ls1x_clk_init(np, &ls1c_clk_hw_data);
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}
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CLK_OF_DECLARE(ls1b_clk, "loongson,ls1b-clk", ls1b_clk_init);
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CLK_OF_DECLARE(ls1c_clk, "loongson,ls1c-clk", ls1c_clk_init);
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