159 lines
3.8 KiB
C
159 lines
3.8 KiB
C
/*
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* Hisilicon hi6220 SoC divider clock driver
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*
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* Copyright (c) 2015 Hisilicon Limited.
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*
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* Author: Bintian Wang <bintian.wang@huawei.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/clk-provider.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include <linux/err.h>
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#include <linux/spinlock.h>
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#include "clk.h"
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#define div_mask(width) ((1 << (width)) - 1)
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/**
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* struct hi6220_clk_divider - divider clock for hi6220
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*
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* @hw: handle between common and hardware-specific interfaces
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* @reg: register containing divider
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* @shift: shift to the divider bit field
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* @width: width of the divider bit field
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* @mask: mask for setting divider rate
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* @table: the div table that the divider supports
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* @lock: register lock
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*/
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struct hi6220_clk_divider {
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struct clk_hw hw;
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void __iomem *reg;
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u8 shift;
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u8 width;
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u32 mask;
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const struct clk_div_table *table;
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spinlock_t *lock;
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};
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#define to_hi6220_clk_divider(_hw) \
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container_of(_hw, struct hi6220_clk_divider, hw)
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static unsigned long hi6220_clkdiv_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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unsigned int val;
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struct hi6220_clk_divider *dclk = to_hi6220_clk_divider(hw);
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val = readl_relaxed(dclk->reg) >> dclk->shift;
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val &= div_mask(dclk->width);
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return divider_recalc_rate(hw, parent_rate, val, dclk->table,
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CLK_DIVIDER_ROUND_CLOSEST);
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}
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static long hi6220_clkdiv_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 hi6220_clk_divider *dclk = to_hi6220_clk_divider(hw);
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return divider_round_rate(hw, rate, prate, dclk->table,
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dclk->width, CLK_DIVIDER_ROUND_CLOSEST);
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}
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static int hi6220_clkdiv_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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int value;
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unsigned long flags = 0;
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u32 data;
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struct hi6220_clk_divider *dclk = to_hi6220_clk_divider(hw);
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value = divider_get_val(rate, parent_rate, dclk->table,
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dclk->width, CLK_DIVIDER_ROUND_CLOSEST);
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if (dclk->lock)
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spin_lock_irqsave(dclk->lock, flags);
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data = readl_relaxed(dclk->reg);
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data &= ~(div_mask(dclk->width) << dclk->shift);
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data |= value << dclk->shift;
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data |= dclk->mask;
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writel_relaxed(data, dclk->reg);
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if (dclk->lock)
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spin_unlock_irqrestore(dclk->lock, flags);
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return 0;
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}
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static const struct clk_ops hi6220_clkdiv_ops = {
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.recalc_rate = hi6220_clkdiv_recalc_rate,
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.round_rate = hi6220_clkdiv_round_rate,
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.set_rate = hi6220_clkdiv_set_rate,
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};
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struct clk *hi6220_register_clkdiv(struct device *dev, const char *name,
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const char *parent_name, unsigned long flags, void __iomem *reg,
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u8 shift, u8 width, u32 mask_bit, spinlock_t *lock)
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{
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struct hi6220_clk_divider *div;
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struct clk *clk;
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struct clk_init_data init;
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struct clk_div_table *table;
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u32 max_div, min_div;
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int i;
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/* allocate the divider */
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div = kzalloc(sizeof(*div), GFP_KERNEL);
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if (!div)
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return ERR_PTR(-ENOMEM);
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/* Init the divider table */
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max_div = div_mask(width) + 1;
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min_div = 1;
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table = kcalloc(max_div + 1, sizeof(*table), GFP_KERNEL);
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if (!table) {
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kfree(div);
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return ERR_PTR(-ENOMEM);
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}
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for (i = 0; i < max_div; i++) {
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table[i].div = min_div + i;
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table[i].val = table[i].div - 1;
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}
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init.name = name;
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init.ops = &hi6220_clkdiv_ops;
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init.flags = flags;
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init.parent_names = parent_name ? &parent_name : NULL;
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init.num_parents = parent_name ? 1 : 0;
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/* struct hi6220_clk_divider assignments */
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div->reg = reg;
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div->shift = shift;
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div->width = width;
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div->mask = mask_bit ? BIT(mask_bit) : 0;
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div->lock = lock;
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div->hw.init = &init;
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div->table = table;
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/* register the clock */
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clk = clk_register(dev, &div->hw);
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if (IS_ERR(clk)) {
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kfree(table);
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kfree(div);
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}
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return clk;
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}
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