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/*
* Copyright (C) 2012 ST Microelectronics
* Viresh Kumar <viresh.linux@gmail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
* Auxiliary Synthesizer clock implementation
*/
#define pr_fmt(fmt) "clk-aux-synth: " fmt
#include <linux/clk-provider.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>
#include "clk.h"
/*
* DOC: Auxiliary Synthesizer clock
*
* Aux synth gives rate for different values of eq, x and y
*
* Fout from synthesizer can be given from two equations:
* Fout1 = (Fin * X/Y)/2 EQ1
* Fout2 = Fin * X/Y EQ2
*/
#define to_clk_aux(_hw) container_of(_hw, struct clk_aux, hw)
static struct aux_clk_masks default_aux_masks = {
.eq_sel_mask = AUX_EQ_SEL_MASK,
.eq_sel_shift = AUX_EQ_SEL_SHIFT,
.eq1_mask = AUX_EQ1_SEL,
.eq2_mask = AUX_EQ2_SEL,
.xscale_sel_mask = AUX_XSCALE_MASK,
.xscale_sel_shift = AUX_XSCALE_SHIFT,
.yscale_sel_mask = AUX_YSCALE_MASK,
.yscale_sel_shift = AUX_YSCALE_SHIFT,
.enable_bit = AUX_SYNT_ENB,
};
static unsigned long aux_calc_rate(struct clk_hw *hw, unsigned long prate,
int index)
{
struct clk_aux *aux = to_clk_aux(hw);
struct aux_rate_tbl *rtbl = aux->rtbl;
u8 eq = rtbl[index].eq ? 1 : 2;
return (((prate / 10000) * rtbl[index].xscale) /
(rtbl[index].yscale * eq)) * 10000;
}
static long clk_aux_round_rate(struct clk_hw *hw, unsigned long drate,
unsigned long *prate)
{
struct clk_aux *aux = to_clk_aux(hw);
int unused;
return clk_round_rate_index(hw, drate, *prate, aux_calc_rate,
aux->rtbl_cnt, &unused);
}
static unsigned long clk_aux_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_aux *aux = to_clk_aux(hw);
unsigned int num = 1, den = 1, val, eqn;
unsigned long flags = 0;
if (aux->lock)
spin_lock_irqsave(aux->lock, flags);
val = readl_relaxed(aux->reg);
if (aux->lock)
spin_unlock_irqrestore(aux->lock, flags);
eqn = (val >> aux->masks->eq_sel_shift) & aux->masks->eq_sel_mask;
if (eqn == aux->masks->eq1_mask)
den = 2;
/* calculate numerator */
num = (val >> aux->masks->xscale_sel_shift) &
aux->masks->xscale_sel_mask;
/* calculate denominator */
den *= (val >> aux->masks->yscale_sel_shift) &
aux->masks->yscale_sel_mask;
if (!den)
return 0;
return (((parent_rate / 10000) * num) / den) * 10000;
}
/* Configures new clock rate of aux */
static int clk_aux_set_rate(struct clk_hw *hw, unsigned long drate,
unsigned long prate)
{
struct clk_aux *aux = to_clk_aux(hw);
struct aux_rate_tbl *rtbl = aux->rtbl;
unsigned long val, flags = 0;
int i;
clk_round_rate_index(hw, drate, prate, aux_calc_rate, aux->rtbl_cnt,
&i);
if (aux->lock)
spin_lock_irqsave(aux->lock, flags);
val = readl_relaxed(aux->reg) &
~(aux->masks->eq_sel_mask << aux->masks->eq_sel_shift);
val |= (rtbl[i].eq & aux->masks->eq_sel_mask) <<
aux->masks->eq_sel_shift;
val &= ~(aux->masks->xscale_sel_mask << aux->masks->xscale_sel_shift);
val |= (rtbl[i].xscale & aux->masks->xscale_sel_mask) <<
aux->masks->xscale_sel_shift;
val &= ~(aux->masks->yscale_sel_mask << aux->masks->yscale_sel_shift);
val |= (rtbl[i].yscale & aux->masks->yscale_sel_mask) <<
aux->masks->yscale_sel_shift;
writel_relaxed(val, aux->reg);
if (aux->lock)
spin_unlock_irqrestore(aux->lock, flags);
return 0;
}
static struct clk_ops clk_aux_ops = {
.recalc_rate = clk_aux_recalc_rate,
.round_rate = clk_aux_round_rate,
.set_rate = clk_aux_set_rate,
};
struct clk *clk_register_aux(const char *aux_name, const char *gate_name,
const char *parent_name, unsigned long flags, void __iomem *reg,
struct aux_clk_masks *masks, struct aux_rate_tbl *rtbl,
u8 rtbl_cnt, spinlock_t *lock, struct clk **gate_clk)
{
struct clk_aux *aux;
struct clk_init_data init;
struct clk *clk;
if (!aux_name || !parent_name || !reg || !rtbl || !rtbl_cnt) {
pr_err("Invalid arguments passed");
return ERR_PTR(-EINVAL);
}
aux = kzalloc(sizeof(*aux), GFP_KERNEL);
if (!aux) {
pr_err("could not allocate aux clk\n");
return ERR_PTR(-ENOMEM);
}
/* struct clk_aux assignments */
if (!masks)
aux->masks = &default_aux_masks;
else
aux->masks = masks;
aux->reg = reg;
aux->rtbl = rtbl;
aux->rtbl_cnt = rtbl_cnt;
aux->lock = lock;
aux->hw.init = &init;
init.name = aux_name;
init.ops = &clk_aux_ops;
init.flags = flags;
init.parent_names = &parent_name;
init.num_parents = 1;
clk = clk_register(NULL, &aux->hw);
if (IS_ERR_OR_NULL(clk))
goto free_aux;
if (gate_name) {
struct clk *tgate_clk;
tgate_clk = clk_register_gate(NULL, gate_name, aux_name, 0, reg,
aux->masks->enable_bit, 0, lock);
if (IS_ERR_OR_NULL(tgate_clk))
goto free_aux;
if (gate_clk)
*gate_clk = tgate_clk;
}
return clk;
free_aux:
kfree(aux);
pr_err("clk register failed\n");
return NULL;
}
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