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OpenCloudOS-Kernel/arch/arm/mach-at91/clock.c

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/*
* linux/arch/arm/mach-at91/clock.c
*
* Copyright (C) 2005 David Brownell
* Copyright (C) 2005 Ivan Kokshaysky
*
* 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/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <mach/hardware.h>
#include <mach/at91_pmc.h>
#include <mach/cpu.h>
#include <asm/proc-fns.h>
#include "clock.h"
#include "generic.h"
void __iomem *at91_pmc_base;
EXPORT_SYMBOL_GPL(at91_pmc_base);
/*
* There's a lot more which can be done with clocks, including cpufreq
* integration, slow clock mode support (for system suspend), letting
* PLLB be used at other rates (on boards that don't need USB), etc.
*/
#define clk_is_primary(x) ((x)->type & CLK_TYPE_PRIMARY)
#define clk_is_programmable(x) ((x)->type & CLK_TYPE_PROGRAMMABLE)
#define clk_is_peripheral(x) ((x)->type & CLK_TYPE_PERIPHERAL)
#define clk_is_sys(x) ((x)->type & CLK_TYPE_SYSTEM)
/*
* Chips have some kind of clocks : group them by functionality
*/
#define cpu_has_utmi() ( cpu_is_at91sam9rl() \
|| cpu_is_at91sam9g45() \
|| cpu_is_at91sam9x5())
#define cpu_has_800M_plla() ( cpu_is_at91sam9g20() \
|| cpu_is_at91sam9g45() \
|| cpu_is_at91sam9x5() \
|| cpu_is_at91sam9n12())
#define cpu_has_300M_plla() (cpu_is_at91sam9g10())
#define cpu_has_240M_plla() (cpu_is_at91sam9261() \
|| cpu_is_at91sam9263() \
|| cpu_is_at91sam9rl())
#define cpu_has_210M_plla() (cpu_is_at91sam9260())
#define cpu_has_pllb() (!(cpu_is_at91sam9rl() \
|| cpu_is_at91sam9g45() \
|| cpu_is_at91sam9x5() \
|| cpu_is_at91sam9n12()))
#define cpu_has_upll() (cpu_is_at91sam9g45() \
|| cpu_is_at91sam9x5())
/* USB host HS & FS */
#define cpu_has_uhp() (!cpu_is_at91sam9rl())
/* USB device FS only */
#define cpu_has_udpfs() (!(cpu_is_at91sam9rl() \
|| cpu_is_at91sam9g45() \
|| cpu_is_at91sam9x5()))
#define cpu_has_plladiv2() (cpu_is_at91sam9g45() \
|| cpu_is_at91sam9x5() \
|| cpu_is_at91sam9n12())
#define cpu_has_mdiv3() (cpu_is_at91sam9g45() \
|| cpu_is_at91sam9x5() \
|| cpu_is_at91sam9n12())
#define cpu_has_alt_prescaler() (cpu_is_at91sam9x5() \
|| cpu_is_at91sam9n12())
static LIST_HEAD(clocks);
static DEFINE_SPINLOCK(clk_lock);
static u32 at91_pllb_usb_init;
/*
* Four primary clock sources: two crystal oscillators (32K, main), and
* two PLLs. PLLA usually runs the master clock; and PLLB must run at
* 48 MHz (unless no USB function clocks are needed). The main clock and
* both PLLs are turned off to run in "slow clock mode" (system suspend).
*/
static struct clk clk32k = {
.name = "clk32k",
.rate_hz = AT91_SLOW_CLOCK,
.users = 1, /* always on */
.id = 0,
.type = CLK_TYPE_PRIMARY,
};
static struct clk main_clk = {
.name = "main",
.pmc_mask = AT91_PMC_MOSCS, /* in PMC_SR */
.id = 1,
.type = CLK_TYPE_PRIMARY,
};
static struct clk plla = {
.name = "plla",
.parent = &main_clk,
.pmc_mask = AT91_PMC_LOCKA, /* in PMC_SR */
.id = 2,
.type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL,
};
static void pllb_mode(struct clk *clk, int is_on)
{
u32 value;
if (is_on) {
is_on = AT91_PMC_LOCKB;
value = at91_pllb_usb_init;
} else
value = 0;
// REVISIT: Add work-around for AT91RM9200 Errata #26 ?
at91_pmc_write(AT91_CKGR_PLLBR, value);
do {
cpu_relax();
} while ((at91_pmc_read(AT91_PMC_SR) & AT91_PMC_LOCKB) != is_on);
}
static struct clk pllb = {
.name = "pllb",
.parent = &main_clk,
.pmc_mask = AT91_PMC_LOCKB, /* in PMC_SR */
.mode = pllb_mode,
.id = 3,
.type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL,
};
static void pmc_sys_mode(struct clk *clk, int is_on)
{
if (is_on)
at91_pmc_write(AT91_PMC_SCER, clk->pmc_mask);
else
at91_pmc_write(AT91_PMC_SCDR, clk->pmc_mask);
}
static void pmc_uckr_mode(struct clk *clk, int is_on)
{
unsigned int uckr = at91_pmc_read(AT91_CKGR_UCKR);
if (is_on) {
is_on = AT91_PMC_LOCKU;
at91_pmc_write(AT91_CKGR_UCKR, uckr | clk->pmc_mask);
} else
at91_pmc_write(AT91_CKGR_UCKR, uckr & ~(clk->pmc_mask));
do {
cpu_relax();
} while ((at91_pmc_read(AT91_PMC_SR) & AT91_PMC_LOCKU) != is_on);
}
/* USB function clocks (PLLB must be 48 MHz) */
static struct clk udpck = {
.name = "udpck",
.parent = &pllb,
.mode = pmc_sys_mode,
};
struct clk utmi_clk = {
.name = "utmi_clk",
.parent = &main_clk,
.pmc_mask = AT91_PMC_UPLLEN, /* in CKGR_UCKR */
.mode = pmc_uckr_mode,
.type = CLK_TYPE_PLL,
};
static struct clk uhpck = {
.name = "uhpck",
/*.parent = ... we choose parent at runtime */
.mode = pmc_sys_mode,
};
/*
* The master clock is divided from the CPU clock (by 1-4). It's used for
* memory, interfaces to on-chip peripherals, the AIC, and sometimes more
* (e.g baud rate generation). It's sourced from one of the primary clocks.
*/
struct clk mck = {
.name = "mck",
.pmc_mask = AT91_PMC_MCKRDY, /* in PMC_SR */
};
static void pmc_periph_mode(struct clk *clk, int is_on)
{
if (is_on)
at91_pmc_write(AT91_PMC_PCER, clk->pmc_mask);
else
at91_pmc_write(AT91_PMC_PCDR, clk->pmc_mask);
}
static struct clk __init *at91_css_to_clk(unsigned long css)
{
switch (css) {
case AT91_PMC_CSS_SLOW:
return &clk32k;
case AT91_PMC_CSS_MAIN:
return &main_clk;
case AT91_PMC_CSS_PLLA:
return &plla;
case AT91_PMC_CSS_PLLB:
if (cpu_has_upll())
/* CSS_PLLB == CSS_UPLL */
return &utmi_clk;
else if (cpu_has_pllb())
return &pllb;
break;
/* alternate PMC: can use master clock */
case AT91_PMC_CSS_MASTER:
return &mck;
}
return NULL;
}
static int pmc_prescaler_divider(u32 reg)
{
if (cpu_has_alt_prescaler()) {
return 1 << ((reg & AT91_PMC_ALT_PRES) >> PMC_ALT_PRES_OFFSET);
} else {
return 1 << ((reg & AT91_PMC_PRES) >> PMC_PRES_OFFSET);
}
}
static void __clk_enable(struct clk *clk)
{
if (clk->parent)
__clk_enable(clk->parent);
if (clk->users++ == 0 && clk->mode)
clk->mode(clk, 1);
}
int clk_enable(struct clk *clk)
{
unsigned long flags;
spin_lock_irqsave(&clk_lock, flags);
__clk_enable(clk);
spin_unlock_irqrestore(&clk_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_enable);
static void __clk_disable(struct clk *clk)
{
BUG_ON(clk->users == 0);
if (--clk->users == 0 && clk->mode)
clk->mode(clk, 0);
if (clk->parent)
__clk_disable(clk->parent);
}
void clk_disable(struct clk *clk)
{
unsigned long flags;
spin_lock_irqsave(&clk_lock, flags);
__clk_disable(clk);
spin_unlock_irqrestore(&clk_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
unsigned long flags;
unsigned long rate;
spin_lock_irqsave(&clk_lock, flags);
for (;;) {
rate = clk->rate_hz;
if (rate || !clk->parent)
break;
clk = clk->parent;
}
spin_unlock_irqrestore(&clk_lock, flags);
return rate;
}
EXPORT_SYMBOL(clk_get_rate);
/*------------------------------------------------------------------------*/
#ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
/*
* For now, only the programmable clocks support reparenting (MCK could
* do this too, with care) or rate changing (the PLLs could do this too,
* ditto MCK but that's more for cpufreq). Drivers may reparent to get
* a better rate match; we don't.
*/
long clk_round_rate(struct clk *clk, unsigned long rate)
{
unsigned long flags;
unsigned prescale;
unsigned long actual;
unsigned long prev = ULONG_MAX;
if (!clk_is_programmable(clk))
return -EINVAL;
spin_lock_irqsave(&clk_lock, flags);
actual = clk->parent->rate_hz;
for (prescale = 0; prescale < 7; prescale++) {
if (actual > rate)
prev = actual;
if (actual && actual <= rate) {
if ((prev - rate) < (rate - actual)) {
actual = prev;
prescale--;
}
break;
}
actual >>= 1;
}
spin_unlock_irqrestore(&clk_lock, flags);
return (prescale < 7) ? actual : -ENOENT;
}
EXPORT_SYMBOL(clk_round_rate);
int clk_set_rate(struct clk *clk, unsigned long rate)
{
unsigned long flags;
unsigned prescale;
unsigned long prescale_offset, css_mask;
unsigned long actual;
if (!clk_is_programmable(clk))
return -EINVAL;
if (clk->users)
return -EBUSY;
if (cpu_has_alt_prescaler()) {
prescale_offset = PMC_ALT_PRES_OFFSET;
css_mask = AT91_PMC_ALT_PCKR_CSS;
} else {
prescale_offset = PMC_PRES_OFFSET;
css_mask = AT91_PMC_CSS;
}
spin_lock_irqsave(&clk_lock, flags);
actual = clk->parent->rate_hz;
for (prescale = 0; prescale < 7; prescale++) {
if (actual && actual <= rate) {
u32 pckr;
pckr = at91_pmc_read(AT91_PMC_PCKR(clk->id));
pckr &= css_mask; /* keep clock selection */
pckr |= prescale << prescale_offset;
at91_pmc_write(AT91_PMC_PCKR(clk->id), pckr);
clk->rate_hz = actual;
break;
}
actual >>= 1;
}
spin_unlock_irqrestore(&clk_lock, flags);
return (prescale < 7) ? actual : -ENOENT;
}
EXPORT_SYMBOL(clk_set_rate);
struct clk *clk_get_parent(struct clk *clk)
{
return clk->parent;
}
EXPORT_SYMBOL(clk_get_parent);
int clk_set_parent(struct clk *clk, struct clk *parent)
{
unsigned long flags;
if (clk->users)
return -EBUSY;
if (!clk_is_primary(parent) || !clk_is_programmable(clk))
return -EINVAL;
if (cpu_is_at91sam9rl() && parent->id == AT91_PMC_CSS_PLLB)
return -EINVAL;
spin_lock_irqsave(&clk_lock, flags);
clk->rate_hz = parent->rate_hz;
clk->parent = parent;
at91_pmc_write(AT91_PMC_PCKR(clk->id), parent->id);
spin_unlock_irqrestore(&clk_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_set_parent);
/* establish PCK0..PCKN parentage and rate */
static void __init init_programmable_clock(struct clk *clk)
{
struct clk *parent;
u32 pckr;
unsigned int css_mask;
if (cpu_has_alt_prescaler())
css_mask = AT91_PMC_ALT_PCKR_CSS;
else
css_mask = AT91_PMC_CSS;
pckr = at91_pmc_read(AT91_PMC_PCKR(clk->id));
parent = at91_css_to_clk(pckr & css_mask);
clk->parent = parent;
clk->rate_hz = parent->rate_hz / pmc_prescaler_divider(pckr);
}
#endif /* CONFIG_AT91_PROGRAMMABLE_CLOCKS */
/*------------------------------------------------------------------------*/
#ifdef CONFIG_DEBUG_FS
static int at91_clk_show(struct seq_file *s, void *unused)
{
u32 scsr, pcsr, uckr = 0, sr;
struct clk *clk;
scsr = at91_pmc_read(AT91_PMC_SCSR);
pcsr = at91_pmc_read(AT91_PMC_PCSR);
sr = at91_pmc_read(AT91_PMC_SR);
seq_printf(s, "SCSR = %8x\n", scsr);
seq_printf(s, "PCSR = %8x\n", pcsr);
seq_printf(s, "MOR = %8x\n", at91_pmc_read(AT91_CKGR_MOR));
seq_printf(s, "MCFR = %8x\n", at91_pmc_read(AT91_CKGR_MCFR));
seq_printf(s, "PLLA = %8x\n", at91_pmc_read(AT91_CKGR_PLLAR));
if (cpu_has_pllb())
seq_printf(s, "PLLB = %8x\n", at91_pmc_read(AT91_CKGR_PLLBR));
if (cpu_has_utmi()) {
uckr = at91_pmc_read(AT91_CKGR_UCKR);
seq_printf(s, "UCKR = %8x\n", uckr);
}
seq_printf(s, "MCKR = %8x\n", at91_pmc_read(AT91_PMC_MCKR));
if (cpu_has_upll())
seq_printf(s, "USB = %8x\n", at91_pmc_read(AT91_PMC_USB));
seq_printf(s, "SR = %8x\n", sr);
seq_printf(s, "\n");
list_for_each_entry(clk, &clocks, node) {
char *state;
if (clk->mode == pmc_sys_mode)
state = (scsr & clk->pmc_mask) ? "on" : "off";
else if (clk->mode == pmc_periph_mode)
state = (pcsr & clk->pmc_mask) ? "on" : "off";
else if (clk->mode == pmc_uckr_mode)
state = (uckr & clk->pmc_mask) ? "on" : "off";
else if (clk->pmc_mask)
state = (sr & clk->pmc_mask) ? "on" : "off";
else if (clk == &clk32k || clk == &main_clk)
state = "on";
else
state = "";
seq_printf(s, "%-10s users=%2d %-3s %9ld Hz %s\n",
clk->name, clk->users, state, clk_get_rate(clk),
clk->parent ? clk->parent->name : "");
}
return 0;
}
static int at91_clk_open(struct inode *inode, struct file *file)
{
return single_open(file, at91_clk_show, NULL);
}
static const struct file_operations at91_clk_operations = {
.open = at91_clk_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init at91_clk_debugfs_init(void)
{
/* /sys/kernel/debug/at91_clk */
(void) debugfs_create_file("at91_clk", S_IFREG | S_IRUGO, NULL, NULL, &at91_clk_operations);
return 0;
}
postcore_initcall(at91_clk_debugfs_init);
#endif
/*------------------------------------------------------------------------*/
/* Register a new clock */
static void __init at91_clk_add(struct clk *clk)
{
list_add_tail(&clk->node, &clocks);
clk->cl.con_id = clk->name;
clk->cl.clk = clk;
clkdev_add(&clk->cl);
}
int __init clk_register(struct clk *clk)
{
if (clk_is_peripheral(clk)) {
if (!clk->parent)
clk->parent = &mck;
clk->mode = pmc_periph_mode;
}
else if (clk_is_sys(clk)) {
clk->parent = &mck;
clk->mode = pmc_sys_mode;
}
#ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
else if (clk_is_programmable(clk)) {
clk->mode = pmc_sys_mode;
init_programmable_clock(clk);
}
#endif
at91_clk_add(clk);
return 0;
}
/*------------------------------------------------------------------------*/
static u32 __init at91_pll_rate(struct clk *pll, u32 freq, u32 reg)
{
unsigned mul, div;
div = reg & 0xff;
mul = (reg >> 16) & 0x7ff;
if (div && mul) {
freq /= div;
freq *= mul + 1;
} else
freq = 0;
return freq;
}
static u32 __init at91_usb_rate(struct clk *pll, u32 freq, u32 reg)
{
if (pll == &pllb && (reg & AT91_PMC_USB96M))
return freq / 2;
else
return freq;
}
static unsigned __init at91_pll_calc(unsigned main_freq, unsigned out_freq)
{
unsigned i, div = 0, mul = 0, diff = 1 << 30;
unsigned ret = (out_freq > 155000000) ? 0xbe00 : 0x3e00;
/* PLL output max 240 MHz (or 180 MHz per errata) */
if (out_freq > 240000000)
goto fail;
for (i = 1; i < 256; i++) {
int diff1;
unsigned input, mul1;
/*
* PLL input between 1MHz and 32MHz per spec, but lower
* frequences seem necessary in some cases so allow 100K.
* Warning: some newer products need 2MHz min.
*/
input = main_freq / i;
if (cpu_is_at91sam9g20() && input < 2000000)
continue;
if (input < 100000)
continue;
if (input > 32000000)
continue;
mul1 = out_freq / input;
if (cpu_is_at91sam9g20() && mul > 63)
continue;
if (mul1 > 2048)
continue;
if (mul1 < 2)
goto fail;
diff1 = out_freq - input * mul1;
if (diff1 < 0)
diff1 = -diff1;
if (diff > diff1) {
diff = diff1;
div = i;
mul = mul1;
if (diff == 0)
break;
}
}
if (i == 256 && diff > (out_freq >> 5))
goto fail;
return ret | ((mul - 1) << 16) | div;
fail:
return 0;
}
static struct clk *const standard_pmc_clocks[] __initconst = {
/* four primary clocks */
&clk32k,
&main_clk,
&plla,
/* MCK */
&mck
};
/* PLLB generated USB full speed clock init */
static void __init at91_pllb_usbfs_clock_init(unsigned long main_clock)
{
/*
* USB clock init: choose 48 MHz PLLB value,
* disable 48MHz clock during usb peripheral suspend.
*
* REVISIT: assumes MCK doesn't derive from PLLB!
*/
uhpck.parent = &pllb;
at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) | AT91_PMC_USB96M;
pllb.rate_hz = at91_pll_rate(&pllb, main_clock, at91_pllb_usb_init);
if (cpu_is_at91rm9200()) {
uhpck.pmc_mask = AT91RM9200_PMC_UHP;
udpck.pmc_mask = AT91RM9200_PMC_UDP;
at91_pmc_write(AT91_PMC_SCER, AT91RM9200_PMC_MCKUDP);
} else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() ||
cpu_is_at91sam9263() || cpu_is_at91sam9g20() ||
cpu_is_at91sam9g10()) {
uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
udpck.pmc_mask = AT91SAM926x_PMC_UDP;
}
at91_pmc_write(AT91_CKGR_PLLBR, 0);
udpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init);
uhpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init);
}
/* UPLL generated USB full speed clock init */
static void __init at91_upll_usbfs_clock_init(unsigned long main_clock)
{
/*
* USB clock init: choose 480 MHz from UPLL,
*/
unsigned int usbr = AT91_PMC_USBS_UPLL;
/* Setup divider by 10 to reach 48 MHz */
usbr |= ((10 - 1) << 8) & AT91_PMC_OHCIUSBDIV;
at91_pmc_write(AT91_PMC_USB, usbr);
/* Now set uhpck values */
uhpck.parent = &utmi_clk;
uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
uhpck.rate_hz = utmi_clk.rate_hz;
uhpck.rate_hz /= 1 + ((at91_pmc_read(AT91_PMC_USB) & AT91_PMC_OHCIUSBDIV) >> 8);
}
static int __init at91_pmc_init(unsigned long main_clock)
{
unsigned tmp, freq, mckr;
int i;
int pll_overclock = false;
/*
* When the bootloader initialized the main oscillator correctly,
* there's no problem using the cycle counter. But if it didn't,
* or when using oscillator bypass mode, we must be told the speed
* of the main clock.
*/
if (!main_clock) {
do {
tmp = at91_pmc_read(AT91_CKGR_MCFR);
} while (!(tmp & AT91_PMC_MAINRDY));
main_clock = (tmp & AT91_PMC_MAINF) * (AT91_SLOW_CLOCK / 16);
}
main_clk.rate_hz = main_clock;
/* report if PLLA is more than mildly overclocked */
plla.rate_hz = at91_pll_rate(&plla, main_clock, at91_pmc_read(AT91_CKGR_PLLAR));
if (cpu_has_300M_plla()) {
if (plla.rate_hz > 300000000)
pll_overclock = true;
} else if (cpu_has_800M_plla()) {
if (plla.rate_hz > 800000000)
pll_overclock = true;
} else if (cpu_has_240M_plla()) {
if (plla.rate_hz > 240000000)
pll_overclock = true;
} else if (cpu_has_210M_plla()) {
if (plla.rate_hz > 210000000)
pll_overclock = true;
} else {
if (plla.rate_hz > 209000000)
pll_overclock = true;
}
if (pll_overclock)
pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000);
if (cpu_has_plladiv2()) {
mckr = at91_pmc_read(AT91_PMC_MCKR);
plla.rate_hz /= (1 << ((mckr & AT91_PMC_PLLADIV2) >> 12)); /* plla divisor by 2 */
}
if (!cpu_has_pllb() && cpu_has_upll()) {
/* setup UTMI clock as the fourth primary clock
* (instead of pllb) */
utmi_clk.type |= CLK_TYPE_PRIMARY;
utmi_clk.id = 3;
}
/*
* USB HS clock init
*/
if (cpu_has_utmi()) {
/*
* multiplier is hard-wired to 40
* (obtain the USB High Speed 480 MHz when input is 12 MHz)
*/
utmi_clk.rate_hz = 40 * utmi_clk.parent->rate_hz;
/* UTMI bias and PLL are managed at the same time */
if (cpu_has_upll())
utmi_clk.pmc_mask |= AT91_PMC_BIASEN;
}
/*
* USB FS clock init
*/
if (cpu_has_pllb())
at91_pllb_usbfs_clock_init(main_clock);
if (cpu_has_upll())
/* assumes that we choose UPLL for USB and not PLLA */
at91_upll_usbfs_clock_init(main_clock);
/*
* MCK and CPU derive from one of those primary clocks.
* For now, assume this parentage won't change.
*/
mckr = at91_pmc_read(AT91_PMC_MCKR);
mck.parent = at91_css_to_clk(mckr & AT91_PMC_CSS);
freq = mck.parent->rate_hz;
freq /= pmc_prescaler_divider(mckr); /* prescale */
if (cpu_is_at91rm9200()) {
mck.rate_hz = freq / (1 + ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
} else if (cpu_is_at91sam9g20()) {
mck.rate_hz = (mckr & AT91_PMC_MDIV) ?
freq / ((mckr & AT91_PMC_MDIV) >> 7) : freq; /* mdiv ; (x >> 7) = ((x >> 8) * 2) */
if (mckr & AT91_PMC_PDIV)
freq /= 2; /* processor clock division */
} else if (cpu_has_mdiv3()) {
mck.rate_hz = (mckr & AT91_PMC_MDIV) == AT91SAM9_PMC_MDIV_3 ?
freq / 3 : freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
} else {
mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
}
if (cpu_has_alt_prescaler()) {
/* Programmable clocks can use MCK */
mck.type |= CLK_TYPE_PRIMARY;
mck.id = 4;
}
/* Register the PMC's standard clocks */
for (i = 0; i < ARRAY_SIZE(standard_pmc_clocks); i++)
at91_clk_add(standard_pmc_clocks[i]);
if (cpu_has_pllb())
at91_clk_add(&pllb);
if (cpu_has_uhp())
at91_clk_add(&uhpck);
if (cpu_has_udpfs())
at91_clk_add(&udpck);
if (cpu_has_utmi())
at91_clk_add(&utmi_clk);
/* MCK and CPU clock are "always on" */
clk_enable(&mck);
printk("Clocks: CPU %u MHz, master %u MHz, main %u.%03u MHz\n",
freq / 1000000, (unsigned) mck.rate_hz / 1000000,
(unsigned) main_clock / 1000000,
((unsigned) main_clock % 1000000) / 1000);
return 0;
}
#if defined(CONFIG_OF)
static struct of_device_id pmc_ids[] = {
{ .compatible = "atmel,at91rm9200-pmc" },
{ /*sentinel*/ }
};
static struct of_device_id osc_ids[] = {
{ .compatible = "atmel,osc" },
{ /*sentinel*/ }
};
int __init at91_dt_clock_init(void)
{
struct device_node *np;
u32 main_clock = 0;
np = of_find_matching_node(NULL, pmc_ids);
if (!np)
panic("unable to find compatible pmc node in dtb\n");
at91_pmc_base = of_iomap(np, 0);
if (!at91_pmc_base)
panic("unable to map pmc cpu registers\n");
of_node_put(np);
/* retrieve the freqency of fixed clocks from device tree */
np = of_find_matching_node(NULL, osc_ids);
if (np) {
u32 rate;
if (!of_property_read_u32(np, "clock-frequency", &rate))
main_clock = rate;
}
of_node_put(np);
return at91_pmc_init(main_clock);
}
#endif
int __init at91_clock_init(unsigned long main_clock)
{
at91_pmc_base = ioremap(AT91_PMC, 256);
if (!at91_pmc_base)
panic("Impossible to ioremap AT91_PMC 0x%x\n", AT91_PMC);
return at91_pmc_init(main_clock);
}
/*
* Several unused clocks may be active. Turn them off.
*/
static int __init at91_clock_reset(void)
{
unsigned long pcdr = 0;
unsigned long scdr = 0;
struct clk *clk;
list_for_each_entry(clk, &clocks, node) {
if (clk->users > 0)
continue;
if (clk->mode == pmc_periph_mode)
pcdr |= clk->pmc_mask;
if (clk->mode == pmc_sys_mode)
scdr |= clk->pmc_mask;
pr_debug("Clocks: disable unused %s\n", clk->name);
}
at91_pmc_write(AT91_PMC_PCDR, pcdr);
at91_pmc_write(AT91_PMC_SCDR, scdr);
return 0;
}
late_initcall(at91_clock_reset);
void at91sam9_idle(void)
{
at91_pmc_write(AT91_PMC_SCDR, AT91_PMC_PCK);
cpu_do_idle();
}
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