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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/of_address.h>
#include <linux/of_irq.h>
#include <linux/io.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include "pmc.h"
#define PROG_SOURCE_MAX 5
#define PROG_ID_MAX 7
#define PROG_STATUS_MASK(id) (1 << ((id) + 8))
#define PROG_PRES_MASK 0x7
#define PROG_MAX_RM9200_CSS 3
struct clk_programmable_layout {
u8 pres_shift;
u8 css_mask;
u8 have_slck_mck;
};
struct clk_programmable {
struct clk_hw hw;
struct at91_pmc *pmc;
unsigned int irq;
wait_queue_head_t wait;
u8 id;
u8 css;
u8 pres;
u8 slckmck;
const struct clk_programmable_layout *layout;
};
#define to_clk_programmable(hw) container_of(hw, struct clk_programmable, hw)
static irqreturn_t clk_programmable_irq_handler(int irq, void *dev_id)
{
struct clk_programmable *prog = (struct clk_programmable *)dev_id;
wake_up(&prog->wait);
return IRQ_HANDLED;
}
static int clk_programmable_prepare(struct clk_hw *hw)
{
u32 tmp;
struct clk_programmable *prog = to_clk_programmable(hw);
struct at91_pmc *pmc = prog->pmc;
const struct clk_programmable_layout *layout = prog->layout;
u8 id = prog->id;
u32 mask = PROG_STATUS_MASK(id);
tmp = prog->css | (prog->pres << layout->pres_shift);
if (layout->have_slck_mck && prog->slckmck)
tmp |= AT91_PMC_CSSMCK_MCK;
pmc_write(pmc, AT91_PMC_PCKR(id), tmp);
while (!(pmc_read(pmc, AT91_PMC_SR) & mask))
wait_event(prog->wait, pmc_read(pmc, AT91_PMC_SR) & mask);
return 0;
}
static int clk_programmable_is_ready(struct clk_hw *hw)
{
struct clk_programmable *prog = to_clk_programmable(hw);
struct at91_pmc *pmc = prog->pmc;
return !!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_PCKR(prog->id));
}
static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
u32 tmp;
struct clk_programmable *prog = to_clk_programmable(hw);
struct at91_pmc *pmc = prog->pmc;
const struct clk_programmable_layout *layout = prog->layout;
tmp = pmc_read(pmc, AT91_PMC_PCKR(prog->id));
prog->pres = (tmp >> layout->pres_shift) & PROG_PRES_MASK;
return parent_rate >> prog->pres;
}
static long clk_programmable_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
unsigned long best_rate = *parent_rate;
unsigned long best_diff;
unsigned long new_diff;
unsigned long cur_rate;
int shift = shift;
if (rate > *parent_rate)
return *parent_rate;
else
best_diff = *parent_rate - rate;
if (!best_diff)
return best_rate;
for (shift = 1; shift < PROG_PRES_MASK; shift++) {
cur_rate = *parent_rate >> shift;
if (cur_rate > rate)
new_diff = cur_rate - rate;
else
new_diff = rate - cur_rate;
if (!new_diff)
return cur_rate;
if (new_diff < best_diff) {
best_diff = new_diff;
best_rate = cur_rate;
}
if (rate > cur_rate)
break;
}
return best_rate;
}
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;
if (index > layout->css_mask) {
if (index > PROG_MAX_RM9200_CSS && layout->have_slck_mck) {
prog->css = 0;
prog->slckmck = 1;
return 0;
} else {
return -EINVAL;
}
}
prog->css = index;
return 0;
}
static u8 clk_programmable_get_parent(struct clk_hw *hw)
{
u32 tmp;
u8 ret;
struct clk_programmable *prog = to_clk_programmable(hw);
struct at91_pmc *pmc = prog->pmc;
const struct clk_programmable_layout *layout = prog->layout;
tmp = pmc_read(pmc, AT91_PMC_PCKR(prog->id));
prog->css = tmp & layout->css_mask;
ret = prog->css;
if (layout->have_slck_mck) {
prog->slckmck = !!(tmp & AT91_PMC_CSSMCK_MCK);
if (prog->slckmck && !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);
unsigned long best_rate = parent_rate;
unsigned long best_diff;
unsigned long new_diff;
unsigned long cur_rate;
int shift = 0;
if (rate > parent_rate)
return parent_rate;
else
best_diff = parent_rate - rate;
if (!best_diff) {
prog->pres = shift;
return 0;
}
for (shift = 1; shift < PROG_PRES_MASK; shift++) {
cur_rate = parent_rate >> shift;
if (cur_rate > rate)
new_diff = cur_rate - rate;
else
new_diff = rate - cur_rate;
if (!new_diff)
break;
if (new_diff < best_diff) {
best_diff = new_diff;
best_rate = cur_rate;
}
if (rate > cur_rate)
break;
}
prog->pres = shift;
return 0;
}
static const struct clk_ops programmable_ops = {
.prepare = clk_programmable_prepare,
.is_prepared = clk_programmable_is_ready,
.recalc_rate = clk_programmable_recalc_rate,
.round_rate = clk_programmable_round_rate,
.get_parent = clk_programmable_get_parent,
.set_parent = clk_programmable_set_parent,
.set_rate = clk_programmable_set_rate,
};
static struct clk * __init
at91_clk_register_programmable(struct at91_pmc *pmc, unsigned int irq,
const char *name, const char **parent_names,
u8 num_parents, u8 id,
const struct clk_programmable_layout *layout)
{
int ret;
struct clk_programmable *prog;
struct clk *clk = NULL;
struct clk_init_data init;
char irq_name[11];
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 =
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