Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

199 lines (160 sloc) 4.917 kb
/*
* 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;
}
Jump to Line
Something went wrong with that request. Please try again.