sckc.c
/*
* drivers/clk/at91/sckc.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/delay.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/io.h>
#define SLOW_CLOCK_FREQ 32768
#define SLOWCK_SW_CYCLES 5
#define SLOWCK_SW_TIME_USEC ((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
SLOW_CLOCK_FREQ)
#define AT91_SCKC_CR 0x00
#define AT91_SCKC_RCEN (1 << 0)
#define AT91_SCKC_OSC32EN (1 << 1)
#define AT91_SCKC_OSC32BYP (1 << 2)
#define AT91_SCKC_OSCSEL (1 << 3)
struct clk_slow_osc {
struct clk_hw hw;
void __iomem *sckcr;
unsigned long startup_usec;
};
#define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)
struct clk_sama5d4_slow_osc {
struct clk_hw hw;
void __iomem *sckcr;
unsigned long startup_usec;
bool prepared;
};
#define to_clk_sama5d4_slow_osc(hw) container_of(hw, struct clk_sama5d4_slow_osc, hw)
struct clk_slow_rc_osc {
struct clk_hw hw;
void __iomem *sckcr;
unsigned long frequency;
unsigned long accuracy;
unsigned long startup_usec;
};
#define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)
struct clk_sam9x5_slow {
struct clk_hw hw;
void __iomem *sckcr;
u8 parent;
};
#define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)
static int clk_slow_osc_prepare(struct clk_hw *hw)
{
struct clk_slow_osc *osc = to_clk_slow_osc(hw);
void __iomem *sckcr = osc->sckcr;
u32 tmp = readl(sckcr);
if (tmp & (AT91_SCKC_OSC32BYP | AT91_SCKC_OSC32EN))
return 0;
writel(tmp | AT91_SCKC_OSC32EN, sckcr);
usleep_range(osc->startup_usec, osc->startup_usec + 1);
return 0;
}
static void clk_slow_osc_unprepare(struct clk_hw *hw)
{
struct clk_slow_osc *osc = to_clk_slow_osc(hw);
void __iomem *sckcr = osc->sckcr;
u32 tmp = readl(sckcr);
if (tmp & AT91_SCKC_OSC32BYP)
return;
writel(tmp & ~AT91_SCKC_OSC32EN, sckcr);
}
static int clk_slow_osc_is_prepared(struct clk_hw *hw)
{
struct clk_slow_osc *osc = to_clk_slow_osc(hw);
void __iomem *sckcr = osc->sckcr;
u32 tmp = readl(sckcr);
if (tmp & AT91_SCKC_OSC32BYP)
return 1;
return !!(tmp & AT91_SCKC_OSC32EN);
}
static const struct clk_ops slow_osc_ops = {
.prepare = clk_slow_osc_prepare,
.unprepare = clk_slow_osc_unprepare,
.is_prepared = clk_slow_osc_is_prepared,
};
static struct clk_hw * __init
at91_clk_register_slow_osc(void __iomem *sckcr,
const char *name,
const char *parent_name,
unsigned long startup,
bool bypass)
{
struct clk_slow_osc *osc;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
if (!sckcr || !name || !parent_name)
return ERR_PTR(-EINVAL);
osc = kzalloc(sizeof(*osc), GFP_KERNEL);
if (!osc)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &slow_osc_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
init.flags = CLK_IGNORE_UNUSED;
osc->hw.init = &init;
osc->sckcr = sckcr;
osc->startup_usec = startup;
if (bypass)
writel((readl(sckcr) & ~AT91_SCKC_OSC32EN) | AT91_SCKC_OSC32BYP,
sckcr);
hw = &osc->hw;
ret = clk_hw_register(NULL, &osc->hw);
if (ret) {
kfree(osc);
hw = ERR_PTR(ret);
}
return hw;
}
static void __init
of_at91sam9x5_clk_slow_osc_setup(struct device_node *np, void __iomem *sckcr)
{
struct clk_hw *hw;
const char *parent_name;
const char *name = np->name;
u32 startup;
bool bypass;
parent_name = of_clk_get_parent_name(np, 0);
of_property_read_string(np, "clock-output-names", &name);
of_property_read_u32(np, "atmel,startup-time-usec", &startup);
bypass = of_property_read_bool(np, "atmel,osc-bypass");
hw = at91_clk_register_slow_osc(sckcr, name, parent_name, startup,
bypass);
if (IS_ERR(hw))
return;
of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
}
static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
return osc->frequency;
}
static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw,
unsigned long parent_acc)
{
struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
return osc->accuracy;
}
static int clk_slow_rc_osc_prepare(struct clk_hw *hw)
{
struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
void __iomem *sckcr = osc->sckcr;
writel(readl(sckcr) | AT91_SCKC_RCEN, sckcr);
usleep_range(osc->startup_usec, osc->startup_usec + 1);
return 0;
}
static void clk_slow_rc_osc_unprepare(struct clk_hw *hw)
{
struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
void __iomem *sckcr = osc->sckcr;
writel(readl(sckcr) & ~AT91_SCKC_RCEN, sckcr);
}
static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw)
{
struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw);
return !!(readl(osc->sckcr) & AT91_SCKC_RCEN);
}
static const struct clk_ops slow_rc_osc_ops = {
.prepare = clk_slow_rc_osc_prepare,
.unprepare = clk_slow_rc_osc_unprepare,
.is_prepared = clk_slow_rc_osc_is_prepared,
.recalc_rate = clk_slow_rc_osc_recalc_rate,
.recalc_accuracy = clk_slow_rc_osc_recalc_accuracy,
};
static struct clk_hw * __init
at91_clk_register_slow_rc_osc(void __iomem *sckcr,
const char *name,
unsigned long frequency,
unsigned long accuracy,
unsigned long startup)
{
struct clk_slow_rc_osc *osc;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
if (!sckcr || !name)
return ERR_PTR(-EINVAL);
osc = kzalloc(sizeof(*osc), GFP_KERNEL);
if (!osc)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &slow_rc_osc_ops;
init.parent_names = NULL;
init.num_parents = 0;
init.flags = CLK_IGNORE_UNUSED;
osc->hw.init = &init;
osc->sckcr = sckcr;
osc->frequency = frequency;
osc->accuracy = accuracy;
osc->startup_usec = startup;
hw = &osc->hw;
ret = clk_hw_register(NULL, &osc->hw);
if (ret) {
kfree(osc);
hw = ERR_PTR(ret);
}
return hw;
}
static void __init
of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np, void __iomem *sckcr)
{
struct clk_hw *hw;
u32 frequency = 0;
u32 accuracy = 0;
u32 startup = 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);
of_property_read_u32(np, "atmel,startup-time-usec", &startup);
hw = at91_clk_register_slow_rc_osc(sckcr, name, frequency, accuracy,
startup);
if (IS_ERR(hw))
return;
of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
}
static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index)
{
struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
void __iomem *sckcr = slowck->sckcr;
u32 tmp;
if (index > 1)
return -EINVAL;
tmp = readl(sckcr);
if ((!index && !(tmp & AT91_SCKC_OSCSEL)) ||
(index && (tmp & AT91_SCKC_OSCSEL)))
return 0;
if (index)
tmp |= AT91_SCKC_OSCSEL;
else
tmp &= ~AT91_SCKC_OSCSEL;
writel(tmp, sckcr);
usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1);
return 0;
}
static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw)
{
struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw);
return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL);
}
static const struct clk_ops sam9x5_slow_ops = {
.set_parent = clk_sam9x5_slow_set_parent,
.get_parent = clk_sam9x5_slow_get_parent,
};
static struct clk_hw * __init
at91_clk_register_sam9x5_slow(void __iomem *sckcr,
const char *name,
const char **parent_names,
int num_parents)
{
struct clk_sam9x5_slow *slowck;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
if (!sckcr || !name || !parent_names || !num_parents)
return ERR_PTR(-EINVAL);
slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
if (!slowck)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &sam9x5_slow_ops;
init.parent_names = parent_names;
init.num_parents = num_parents;
init.flags = 0;
slowck->hw.init = &init;
slowck->sckcr = sckcr;
slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL);
hw = &slowck->hw;
ret = clk_hw_register(NULL, &slowck->hw);
if (ret) {
kfree(slowck);
hw = ERR_PTR(ret);
}
return hw;
}
static void __init
of_at91sam9x5_clk_slow_setup(struct device_node *np, void __iomem *sckcr)
{
struct clk_hw *hw;
const char *parent_names[2];
unsigned int num_parents;
const char *name = np->name;
num_parents = of_clk_get_parent_count(np);
if (num_parents == 0 || num_parents > 2)
return;
of_clk_parent_fill(np, parent_names, num_parents);
of_property_read_string(np, "clock-output-names", &name);
hw = at91_clk_register_sam9x5_slow(sckcr, name, parent_names,
num_parents);
if (IS_ERR(hw))
return;
of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
}
static const struct of_device_id sckc_clk_ids[] __initconst = {
/* Slow clock */
{
.compatible = "atmel,at91sam9x5-clk-slow-osc",
.data = of_at91sam9x5_clk_slow_osc_setup,
},
{
.compatible = "atmel,at91sam9x5-clk-slow-rc-osc",
.data = of_at91sam9x5_clk_slow_rc_osc_setup,
},
{
.compatible = "atmel,at91sam9x5-clk-slow",
.data = of_at91sam9x5_clk_slow_setup,
},
{ /*sentinel*/ }
};
static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
{
struct device_node *childnp;
void (*clk_setup)(struct device_node *, void __iomem *);
const struct of_device_id *clk_id;
void __iomem *regbase = of_iomap(np, 0);
if (!regbase)
return;
for_each_child_of_node(np, childnp) {
clk_id = of_match_node(sckc_clk_ids, childnp);
if (!clk_id)
continue;
clk_setup = clk_id->data;
clk_setup(childnp, regbase);
}
}
CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc",
of_at91sam9x5_sckc_setup);
static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw)
{
struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
if (osc->prepared)
return 0;
/*
* Assume that if it has already been selected (for example by the
* bootloader), enough time has aready passed.
*/
if ((readl(osc->sckcr) & AT91_SCKC_OSCSEL)) {
osc->prepared = true;
return 0;
}
usleep_range(osc->startup_usec, osc->startup_usec + 1);
osc->prepared = true;
return 0;
}
static int clk_sama5d4_slow_osc_is_prepared(struct clk_hw *hw)
{
struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw);
return osc->prepared;
}
static const struct clk_ops sama5d4_slow_osc_ops = {
.prepare = clk_sama5d4_slow_osc_prepare,
.is_prepared = clk_sama5d4_slow_osc_is_prepared,
};
static void __init of_sama5d4_sckc_setup(struct device_node *np)
{
void __iomem *regbase = of_iomap(np, 0);
struct clk_hw *hw;
struct clk_sama5d4_slow_osc *osc;
struct clk_init_data init;
const char *xtal_name;
const char *parent_names[2] = { "slow_rc_osc", "slow_osc" };
bool bypass;
int ret;
if (!regbase)
return;
hw = clk_hw_register_fixed_rate_with_accuracy(NULL, parent_names[0],
NULL, 0, 32768,
250000000);
if (IS_ERR(hw))
return;
xtal_name = of_clk_get_parent_name(np, 0);
bypass = of_property_read_bool(np, "atmel,osc-bypass");
osc = kzalloc(sizeof(*osc), GFP_KERNEL);
if (!osc)
return;
init.name = parent_names[1];
init.ops = &sama5d4_slow_osc_ops;
init.parent_names = &xtal_name;
init.num_parents = 1;
init.flags = CLK_IGNORE_UNUSED;
osc->hw.init = &init;
osc->sckcr = regbase;
osc->startup_usec = 1200000;
if (bypass)
writel((readl(regbase) | AT91_SCKC_OSC32BYP), regbase);
hw = &osc->hw;
ret = clk_hw_register(NULL, &osc->hw);
if (ret) {
kfree(osc);
return;
}
hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2);
if (IS_ERR(hw))
return;
of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
}
CLK_OF_DECLARE(sama5d4_clk_sckc, "atmel,sama5d4-sckc",
of_sama5d4_sckc_setup);