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/*
* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/clk/at91_pmc.h>
#include <linux/of.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include "pmc.h"
#define PROG_ID_MAX 7
#define PROG_STATUS_MASK(id) (1 << ((id) + 8))
#define PROG_PRES(layout, pckr) ((pckr >> layout->pres_shift) & layout->pres_mask)
#define PROG_MAX_RM9200_CSS 3
struct clk_programmable {
struct clk_hw hw;
struct regmap *regmap;
u8 id;
const struct clk_programmable_layout *layout;
};
#define to_clk_programmable(hw) container_of(hw, struct clk_programmable, hw)
static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_programmable *prog = to_clk_programmable(hw);
const struct clk_programmable_layout *layout = prog->layout;
unsigned int pckr;
unsigned long rate;
regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr);
if (layout->is_pres_direct)
rate = parent_rate / (PROG_PRES(layout, pckr) + 1);
else
rate = parent_rate >> PROG_PRES(layout, pckr);
return rate;
}
static int clk_programmable_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct clk_programmable *prog = to_clk_programmable(hw);
const struct clk_programmable_layout *layout = prog->layout;
struct clk_hw *parent;
long best_rate = -EINVAL;
unsigned long parent_rate;
unsigned long tmp_rate = 0;
int shift;
int i;
for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
parent = clk_hw_get_parent_by_index(hw, i);
if (!parent)
continue;
parent_rate = clk_hw_get_rate(parent);
if (layout->is_pres_direct) {
for (shift = 0; shift <= layout->pres_mask; shift++) {
tmp_rate = parent_rate / (shift + 1);
if (tmp_rate <= req->rate)
break;
}
} else {
for (shift = 0; shift < layout->pres_mask; shift++) {
tmp_rate = parent_rate >> shift;
if (tmp_rate <= req->rate)
break;
}
}
if (tmp_rate > req->rate)
continue;
if (best_rate < 0 ||
(req->rate - tmp_rate) < (req->rate - best_rate)) {
best_rate = tmp_rate;
req->best_parent_rate = parent_rate;
req->best_parent_hw = parent;
}
if (!best_rate)
break;
}
if (best_rate < 0)
return best_rate;
req->rate = best_rate;
return 0;
}
static int clk_programmable_set_parent(struct clk_hw *hw, u8 index)
{
struct clk_programmable *prog = to_clk_programmable(hw);
const struct clk_programmable_layout *layout = prog->layout;
unsigned int mask = layout->css_mask;
unsigned int pckr = index;
if (layout->have_slck_mck)
mask |= AT91_PMC_CSSMCK_MCK;
if (index > layout->css_mask) {
if (index > PROG_MAX_RM9200_CSS && !layout->have_slck_mck)
return -EINVAL;
pckr |= AT91_PMC_CSSMCK_MCK;
}
regmap_update_bits(prog->regmap, AT91_PMC_PCKR(prog->id), mask, pckr);
return 0;
}
static u8 clk_programmable_get_parent(struct clk_hw *hw)
{
struct clk_programmable *prog = to_clk_programmable(hw);
const struct clk_programmable_layout *layout = prog->layout;
unsigned int pckr;
u8 ret;
regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr);
ret = pckr & layout->css_mask;
if (layout->have_slck_mck && (pckr & AT91_PMC_CSSMCK_MCK) && !ret)
ret = PROG_MAX_RM9200_CSS + 1;
return ret;
}
static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_programmable *prog = to_clk_programmable(hw);
const struct clk_programmable_layout *layout = prog->layout;
unsigned long div = parent_rate / rate;
int shift = 0;
if (!div)
return -EINVAL;
if (layout->is_pres_direct) {
shift = div - 1;
if (shift > layout->pres_mask)
return -EINVAL;
} else {
shift = fls(div) - 1;
if (div != (1 << shift))
return -EINVAL;
if (shift >= layout->pres_mask)
return -EINVAL;
}
regmap_update_bits(prog->regmap, AT91_PMC_PCKR(prog->id),
layout->pres_mask << layout->pres_shift,
shift << layout->pres_shift);
return 0;
}
static const struct clk_ops programmable_ops = {
.recalc_rate = clk_programmable_recalc_rate,
.determine_rate = clk_programmable_determine_rate,
.get_parent = clk_programmable_get_parent,
.set_parent = clk_programmable_set_parent,
.set_rate = clk_programmable_set_rate,
};
struct clk_hw * __init
at91_clk_register_programmable(struct regmap *regmap,
const char *name, const char **parent_names,
u8 num_parents, u8 id,
const struct clk_programmable_layout *layout)
{
struct clk_programmable *prog;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
if (id > PROG_ID_MAX)
return ERR_PTR(-EINVAL);
prog = kzalloc(sizeof(*prog), GFP_KERNEL);
if (!prog)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &programmable_ops;
init.parent_names = parent_names;
init.num_parents = num_parents;
init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
prog->id = id;
prog->layout = layout;
prog->hw.init = &init;
prog->regmap = regmap;
hw = &prog->hw;
ret = clk_hw_register(NULL, &prog->hw);
if (ret) {
kfree(prog);
hw = ERR_PTR(ret);
} else {
pmc_register_pck(id);
}
return hw;
}
const struct clk_programmable_layout at91rm9200_programmable_layout = {
.pres_mask = 0x7,
.pres_shift = 2,
.css_mask = 0x3,
.have_slck_mck = 0,
.is_pres_direct = 0,
};
const struct clk_programmable_layout at91sam9g45_programmable_layout = {
.pres_mask = 0x7,
.pres_shift = 2,
.css_mask = 0x3,
.have_slck_mck = 1,
.is_pres_direct = 0,
};
const struct clk_programmable_layout at91sam9x5_programmable_layout = {
.pres_mask = 0x7,
.pres_shift = 4,
.css_mask = 0x7,
.have_slck_mck = 0,
.is_pres_direct = 0,
};
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