linux/drivers/clk/at91/clk-main.c
Boris BREZILLON 27cb1c2083 clk: at91: rework main clk implementation
AT91 main clk is a clk multiplexer and not a simple fixed rate clk as
currently implemented.

In some SoCs (sam9x5, sama5, sam9g45 families) this multiplexer can
choose among 2 sources: an internal RC oscillator circuit and an
oscillator using an external crystal.

In other Socs (sam9260, rm9200 families) the multiplexer source is
hardcoded to the external crystal oscillator.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2014-05-07 18:27:22 +02:00

639 lines
15 KiB
C

/*
* 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/delay.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include "pmc.h"
#define SLOW_CLOCK_FREQ 32768
#define MAINF_DIV 16
#define MAINFRDY_TIMEOUT (((MAINF_DIV + 1) * USEC_PER_SEC) / \
SLOW_CLOCK_FREQ)
#define MAINF_LOOP_MIN_WAIT (USEC_PER_SEC / SLOW_CLOCK_FREQ)
#define MAINF_LOOP_MAX_WAIT MAINFRDY_TIMEOUT
#define MOR_KEY_MASK (0xff << 16)
struct clk_main_osc {
struct clk_hw hw;
struct at91_pmc *pmc;
unsigned int irq;
wait_queue_head_t wait;
};
#define to_clk_main_osc(hw) container_of(hw, struct clk_main_osc, hw)
struct clk_main_rc_osc {
struct clk_hw hw;
struct at91_pmc *pmc;
unsigned int irq;
wait_queue_head_t wait;
unsigned long frequency;
unsigned long accuracy;
};
#define to_clk_main_rc_osc(hw) container_of(hw, struct clk_main_rc_osc, hw)
struct clk_rm9200_main {
struct clk_hw hw;
struct at91_pmc *pmc;
};
#define to_clk_rm9200_main(hw) container_of(hw, struct clk_rm9200_main, hw)
struct clk_sam9x5_main {
struct clk_hw hw;
struct at91_pmc *pmc;
unsigned int irq;
wait_queue_head_t wait;
u8 parent;
};
#define to_clk_sam9x5_main(hw) container_of(hw, struct clk_sam9x5_main, hw)
static irqreturn_t clk_main_osc_irq_handler(int irq, void *dev_id)
{
struct clk_main_osc *osc = dev_id;
wake_up(&osc->wait);
disable_irq_nosync(osc->irq);
return IRQ_HANDLED;
}
static int clk_main_osc_prepare(struct clk_hw *hw)
{
struct clk_main_osc *osc = to_clk_main_osc(hw);
struct at91_pmc *pmc = osc->pmc;
u32 tmp;
tmp = pmc_read(pmc, AT91_CKGR_MOR) & ~MOR_KEY_MASK;
if (tmp & AT91_PMC_OSCBYPASS)
return 0;
if (!(tmp & AT91_PMC_MOSCEN)) {
tmp |= AT91_PMC_MOSCEN | AT91_PMC_KEY;
pmc_write(pmc, AT91_CKGR_MOR, tmp);
}
while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS)) {
enable_irq(osc->irq);
wait_event(osc->wait,
pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS);
}
return 0;
}
static void clk_main_osc_unprepare(struct clk_hw *hw)
{
struct clk_main_osc *osc = to_clk_main_osc(hw);
struct at91_pmc *pmc = osc->pmc;
u32 tmp = pmc_read(pmc, AT91_CKGR_MOR);
if (tmp & AT91_PMC_OSCBYPASS)
return;
if (!(tmp & AT91_PMC_MOSCEN))
return;
tmp &= ~(AT91_PMC_KEY | AT91_PMC_MOSCEN);
pmc_write(pmc, AT91_CKGR_MOR, tmp | AT91_PMC_KEY);
}
static int clk_main_osc_is_prepared(struct clk_hw *hw)
{
struct clk_main_osc *osc = to_clk_main_osc(hw);
struct at91_pmc *pmc = osc->pmc;
u32 tmp = pmc_read(pmc, AT91_CKGR_MOR);
if (tmp & AT91_PMC_OSCBYPASS)
return 1;
return !!((pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCS) &&
(pmc_read(pmc, AT91_CKGR_MOR) & AT91_PMC_MOSCEN));
}
static const struct clk_ops main_osc_ops = {
.prepare = clk_main_osc_prepare,
.unprepare = clk_main_osc_unprepare,
.is_prepared = clk_main_osc_is_prepared,
};
static struct clk * __init
at91_clk_register_main_osc(struct at91_pmc *pmc,
unsigned int irq,
const char *name,
const char *parent_name,
bool bypass)
{
int ret;
struct clk_main_osc *osc;
struct clk *clk = NULL;
struct clk_init_data init;
if (!pmc || !irq || !name || !parent_name)
return ERR_PTR(-EINVAL);
osc = kzalloc(sizeof(*osc), GFP_KERNEL);
if (!osc)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &main_osc_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
init.flags = CLK_IGNORE_UNUSED;
osc->hw.init = &init;
osc->pmc = pmc;
osc->irq = irq;
init_waitqueue_head(&osc->wait);
irq_set_status_flags(osc->irq, IRQ_NOAUTOEN);
ret = request_irq(osc->irq, clk_main_osc_irq_handler,
IRQF_TRIGGER_HIGH, name, osc);
if (ret)
return ERR_PTR(ret);
if (bypass)
pmc_write(pmc, AT91_CKGR_MOR,
(pmc_read(pmc, AT91_CKGR_MOR) &
~(MOR_KEY_MASK | AT91_PMC_MOSCEN)) |
AT91_PMC_OSCBYPASS | AT91_PMC_KEY);
clk = clk_register(NULL, &osc->hw);
if (IS_ERR(clk)) {
free_irq(irq, osc);
kfree(osc);
}
return clk;
}
void __init of_at91rm9200_clk_main_osc_setup(struct device_node *np,
struct at91_pmc *pmc)
{
struct clk *clk;
unsigned int irq;
const char *name = np->name;
const char *parent_name;
bool bypass;
of_property_read_string(np, "clock-output-names", &name);
bypass = of_property_read_bool(np, "atmel,osc-bypass");
parent_name = of_clk_get_parent_name(np, 0);
irq = irq_of_parse_and_map(np, 0);
if (!irq)
return;
clk = at91_clk_register_main_osc(pmc, irq, name, parent_name, bypass);
if (IS_ERR(clk))
return;
of_clk_add_provider(np, of_clk_src_simple_get, clk);
}
static irqreturn_t clk_main_rc_osc_irq_handler(int irq, void *dev_id)
{
struct clk_main_rc_osc *osc = dev_id;
wake_up(&osc->wait);
disable_irq_nosync(osc->irq);
return IRQ_HANDLED;
}
static int clk_main_rc_osc_prepare(struct clk_hw *hw)
{
struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
struct at91_pmc *pmc = osc->pmc;
u32 tmp;
tmp = pmc_read(pmc, AT91_CKGR_MOR) & ~MOR_KEY_MASK;
if (!(tmp & AT91_PMC_MOSCRCEN)) {
tmp |= AT91_PMC_MOSCRCEN | AT91_PMC_KEY;
pmc_write(pmc, AT91_CKGR_MOR, tmp);
}
while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCRCS)) {
enable_irq(osc->irq);
wait_event(osc->wait,
pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCRCS);
}
return 0;
}
static void clk_main_rc_osc_unprepare(struct clk_hw *hw)
{
struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
struct at91_pmc *pmc = osc->pmc;
u32 tmp = pmc_read(pmc, AT91_CKGR_MOR);
if (!(tmp & AT91_PMC_MOSCRCEN))
return;
tmp &= ~(MOR_KEY_MASK | AT91_PMC_MOSCRCEN);
pmc_write(pmc, AT91_CKGR_MOR, tmp | AT91_PMC_KEY);
}
static int clk_main_rc_osc_is_prepared(struct clk_hw *hw)
{
struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
struct at91_pmc *pmc = osc->pmc;
return !!((pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCRCS) &&
(pmc_read(pmc, AT91_CKGR_MOR) & AT91_PMC_MOSCRCEN));
}
static unsigned long clk_main_rc_osc_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
return osc->frequency;
}
static unsigned long clk_main_rc_osc_recalc_accuracy(struct clk_hw *hw,
unsigned long parent_acc)
{
struct clk_main_rc_osc *osc = to_clk_main_rc_osc(hw);
return osc->accuracy;
}
static const struct clk_ops main_rc_osc_ops = {
.prepare = clk_main_rc_osc_prepare,
.unprepare = clk_main_rc_osc_unprepare,
.is_prepared = clk_main_rc_osc_is_prepared,
.recalc_rate = clk_main_rc_osc_recalc_rate,
.recalc_accuracy = clk_main_rc_osc_recalc_accuracy,
};
static struct clk * __init
at91_clk_register_main_rc_osc(struct at91_pmc *pmc,
unsigned int irq,
const char *name,
u32 frequency, u32 accuracy)
{
int ret;
struct clk_main_rc_osc *osc;
struct clk *clk = NULL;
struct clk_init_data init;
if (!pmc || !irq || !name || !frequency)
return ERR_PTR(-EINVAL);
osc = kzalloc(sizeof(*osc), GFP_KERNEL);
if (!osc)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &main_rc_osc_ops;
init.parent_names = NULL;
init.num_parents = 0;
init.flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED;
osc->hw.init = &init;
osc->pmc = pmc;
osc->irq = irq;
osc->frequency = frequency;
osc->accuracy = accuracy;
init_waitqueue_head(&osc->wait);
irq_set_status_flags(osc->irq, IRQ_NOAUTOEN);
ret = request_irq(osc->irq, clk_main_rc_osc_irq_handler,
IRQF_TRIGGER_HIGH, name, osc);
if (ret)
return ERR_PTR(ret);
clk = clk_register(NULL, &osc->hw);
if (IS_ERR(clk)) {
free_irq(irq, osc);
kfree(osc);
}
return clk;
}
void __init of_at91sam9x5_clk_main_rc_osc_setup(struct device_node *np,
struct at91_pmc *pmc)
{
struct clk *clk;
unsigned int irq;
u32 frequency = 0;
u32 accuracy = 0;
const char *name = np->name;
of_property_read_string(np, "clock-output-names", &name);
of_property_read_u32(np, "clock-frequency", &frequency);
of_property_read_u32(np, "clock-accuracy", &accuracy);
irq = irq_of_parse_and_map(np, 0);
if (!irq)
return;
clk = at91_clk_register_main_rc_osc(pmc, irq, name, frequency,
accuracy);
if (IS_ERR(clk))
return;
of_clk_add_provider(np, of_clk_src_simple_get, clk);
}
static int clk_main_probe_frequency(struct at91_pmc *pmc)
{
unsigned long prep_time, timeout;
u32 tmp;
timeout = jiffies + usecs_to_jiffies(MAINFRDY_TIMEOUT);
do {
prep_time = jiffies;
tmp = pmc_read(pmc, AT91_CKGR_MCFR);
if (tmp & AT91_PMC_MAINRDY)
return 0;
usleep_range(MAINF_LOOP_MIN_WAIT, MAINF_LOOP_MAX_WAIT);
} while (time_before(prep_time, timeout));
return -ETIMEDOUT;
}
static unsigned long clk_main_recalc_rate(struct at91_pmc *pmc,
unsigned long parent_rate)
{
u32 tmp;
if (parent_rate)
return parent_rate;
tmp = pmc_read(pmc, AT91_CKGR_MCFR);
if (!(tmp & AT91_PMC_MAINRDY))
return 0;
return ((tmp & AT91_PMC_MAINF) * SLOW_CLOCK_FREQ) / MAINF_DIV;
}
static int clk_rm9200_main_prepare(struct clk_hw *hw)
{
struct clk_rm9200_main *clkmain = to_clk_rm9200_main(hw);
return clk_main_probe_frequency(clkmain->pmc);
}
static int clk_rm9200_main_is_prepared(struct clk_hw *hw)
{
struct clk_rm9200_main *clkmain = to_clk_rm9200_main(hw);
return !!(pmc_read(clkmain->pmc, AT91_CKGR_MCFR) & AT91_PMC_MAINRDY);
}
static unsigned long clk_rm9200_main_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_rm9200_main *clkmain = to_clk_rm9200_main(hw);
return clk_main_recalc_rate(clkmain->pmc, parent_rate);
}
static const struct clk_ops rm9200_main_ops = {
.prepare = clk_rm9200_main_prepare,
.is_prepared = clk_rm9200_main_is_prepared,
.recalc_rate = clk_rm9200_main_recalc_rate,
};
static struct clk * __init
at91_clk_register_rm9200_main(struct at91_pmc *pmc,
const char *name,
const char *parent_name)
{
struct clk_rm9200_main *clkmain;
struct clk *clk = NULL;
struct clk_init_data init;
if (!pmc || !name)
return ERR_PTR(-EINVAL);
if (!parent_name)
return ERR_PTR(-EINVAL);
clkmain = kzalloc(sizeof(*clkmain), GFP_KERNEL);
if (!clkmain)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &rm9200_main_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
init.flags = 0;
clkmain->hw.init = &init;
clkmain->pmc = pmc;
clk = clk_register(NULL, &clkmain->hw);
if (IS_ERR(clk))
kfree(clkmain);
return clk;
}
void __init of_at91rm9200_clk_main_setup(struct device_node *np,
struct at91_pmc *pmc)
{
struct clk *clk;
const char *parent_name;
const char *name = np->name;
parent_name = of_clk_get_parent_name(np, 0);
of_property_read_string(np, "clock-output-names", &name);
clk = at91_clk_register_rm9200_main(pmc, name, parent_name);
if (IS_ERR(clk))
return;
of_clk_add_provider(np, of_clk_src_simple_get, clk);
}
static irqreturn_t clk_sam9x5_main_irq_handler(int irq, void *dev_id)
{
struct clk_sam9x5_main *clkmain = dev_id;
wake_up(&clkmain->wait);
disable_irq_nosync(clkmain->irq);
return IRQ_HANDLED;
}
static int clk_sam9x5_main_prepare(struct clk_hw *hw)
{
struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
struct at91_pmc *pmc = clkmain->pmc;
while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCSELS)) {
enable_irq(clkmain->irq);
wait_event(clkmain->wait,
pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCSELS);
}
return clk_main_probe_frequency(pmc);
}
static int clk_sam9x5_main_is_prepared(struct clk_hw *hw)
{
struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
return !!(pmc_read(clkmain->pmc, AT91_PMC_SR) & AT91_PMC_MOSCSELS);
}
static unsigned long clk_sam9x5_main_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
return clk_main_recalc_rate(clkmain->pmc, parent_rate);
}
static int clk_sam9x5_main_set_parent(struct clk_hw *hw, u8 index)
{
struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
struct at91_pmc *pmc = clkmain->pmc;
u32 tmp;
if (index > 1)
return -EINVAL;
tmp = pmc_read(pmc, AT91_CKGR_MOR) & ~MOR_KEY_MASK;
if (index && !(tmp & AT91_PMC_MOSCSEL))
pmc_write(pmc, AT91_CKGR_MOR, tmp | AT91_PMC_MOSCSEL);
else if (!index && (tmp & AT91_PMC_MOSCSEL))
pmc_write(pmc, AT91_CKGR_MOR, tmp & ~AT91_PMC_MOSCSEL);
while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCSELS)) {
enable_irq(clkmain->irq);
wait_event(clkmain->wait,
pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MOSCSELS);
}
return 0;
}
static u8 clk_sam9x5_main_get_parent(struct clk_hw *hw)
{
struct clk_sam9x5_main *clkmain = to_clk_sam9x5_main(hw);
return !!(pmc_read(clkmain->pmc, AT91_CKGR_MOR) & AT91_PMC_MOSCEN);
}
static const struct clk_ops sam9x5_main_ops = {
.prepare = clk_sam9x5_main_prepare,
.is_prepared = clk_sam9x5_main_is_prepared,
.recalc_rate = clk_sam9x5_main_recalc_rate,
.set_parent = clk_sam9x5_main_set_parent,
.get_parent = clk_sam9x5_main_get_parent,
};
static struct clk * __init
at91_clk_register_sam9x5_main(struct at91_pmc *pmc,
unsigned int irq,
const char *name,
const char **parent_names,
int num_parents)
{
int ret;
struct clk_sam9x5_main *clkmain;
struct clk *clk = NULL;
struct clk_init_data init;
if (!pmc || !irq || !name)
return ERR_PTR(-EINVAL);
if (!parent_names || !num_parents)
return ERR_PTR(-EINVAL);
clkmain = kzalloc(sizeof(*clkmain), GFP_KERNEL);
if (!clkmain)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &sam9x5_main_ops;
init.parent_names = parent_names;
init.num_parents = num_parents;
init.flags = CLK_SET_PARENT_GATE;
clkmain->hw.init = &init;
clkmain->pmc = pmc;
clkmain->irq = irq;
clkmain->parent = !!(pmc_read(clkmain->pmc, AT91_CKGR_MOR) &
AT91_PMC_MOSCEN);
init_waitqueue_head(&clkmain->wait);
irq_set_status_flags(clkmain->irq, IRQ_NOAUTOEN);
ret = request_irq(clkmain->irq, clk_sam9x5_main_irq_handler,
IRQF_TRIGGER_HIGH, name, clkmain);
if (ret)
return ERR_PTR(ret);
clk = clk_register(NULL, &clkmain->hw);
if (IS_ERR(clk)) {
free_irq(clkmain->irq, clkmain);
kfree(clkmain);
}
return clk;
}
void __init of_at91sam9x5_clk_main_setup(struct device_node *np,
struct at91_pmc *pmc)
{
struct clk *clk;
const char *parent_names[2];
int num_parents;
unsigned int irq;
const char *name = np->name;
int i;
num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
if (num_parents <= 0 || num_parents > 2)
return;
for (i = 0; i < num_parents; ++i) {
parent_names[i] = of_clk_get_parent_name(np, i);
if (!parent_names[i])
return;
}
of_property_read_string(np, "clock-output-names", &name);
irq = irq_of_parse_and_map(np, 0);
if (!irq)
return;
clk = at91_clk_register_sam9x5_main(pmc, irq, name, parent_names,
num_parents);
if (IS_ERR(clk))
return;
of_clk_add_provider(np, of_clk_src_simple_get, clk);
}