linux/drivers/clk/at91/clk-programmable.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

245 lines
5.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
*/
#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,
};