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