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u-boot/arch/arm/mach-at91/arm926ejs/clock.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style 
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

287 lines
6.8 KiB
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// SPDX-License-Identifier: GPL-2.0+
/*
* [origin: Linux kernel linux/arch/arm/mach-at91/clock.c]
*
* Copyright (C) 2005 David Brownell
* Copyright (C) 2005 Ivan Kokshaysky
* Copyright (C) 2009 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/hardware.h>
#include <asm/arch/at91_pmc.h>
#include <asm/arch/clk.h>
#if !defined(CONFIG_AT91FAMILY)
# error You need to define CONFIG_AT91FAMILY in your board config!
#endif
#define EN_PLLB_TIMEOUT 500
DECLARE_GLOBAL_DATA_PTR;
static unsigned long at91_css_to_rate(unsigned long css)
{
switch (css) {
case AT91_PMC_MCKR_CSS_SLOW:
return CONFIG_SYS_AT91_SLOW_CLOCK;
case AT91_PMC_MCKR_CSS_MAIN:
return gd->arch.main_clk_rate_hz;
case AT91_PMC_MCKR_CSS_PLLA:
return gd->arch.plla_rate_hz;
case AT91_PMC_MCKR_CSS_PLLB:
return gd->arch.pllb_rate_hz;
}
return 0;
}
#ifdef CONFIG_USB_ATMEL
static unsigned 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 defined(CONFIG_AT91SAM9G20)
if (input < 2000000)
continue;
#endif
if (input < 100000)
continue;
if (input > 32000000)
continue;
mul1 = out_freq / input;
#if defined(CONFIG_AT91SAM9G20)
if (mul > 63)
continue;
#endif
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;
}
#endif
static u32 at91_pll_rate(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;
}
int at91_clock_init(unsigned long main_clock)
{
unsigned freq, mckr;
at91_pmc_t *pmc = (at91_pmc_t *) ATMEL_BASE_PMC;
#ifndef CONFIG_SYS_AT91_MAIN_CLOCK
unsigned tmp;
/*
* 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 = readl(&pmc->mcfr);
} while (!(tmp & AT91_PMC_MCFR_MAINRDY));
tmp &= AT91_PMC_MCFR_MAINF_MASK;
main_clock = tmp * (CONFIG_SYS_AT91_SLOW_CLOCK / 16);
}
#endif
gd->arch.main_clk_rate_hz = main_clock;
/* report if PLLA is more than mildly overclocked */
gd->arch.plla_rate_hz = at91_pll_rate(main_clock, readl(&pmc->pllar));
#ifdef CONFIG_USB_ATMEL
/*
* USB clock init: choose 48 MHz PLLB value,
* disable 48MHz clock during usb peripheral suspend.
*
* REVISIT: assumes MCK doesn't derive from PLLB!
*/
gd->arch.at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) |
AT91_PMC_PLLBR_USBDIV_2;
gd->arch.pllb_rate_hz = at91_pll_rate(main_clock,
gd->arch.at91_pllb_usb_init);
#endif
/*
* MCK and CPU derive from one of those primary clocks.
* For now, assume this parentage won't change.
*/
mckr = readl(&pmc->mckr);
#if defined(CONFIG_AT91SAM9G45) || defined(CONFIG_AT91SAM9M10G45) \
|| defined(CONFIG_AT91SAM9N12) || defined(CONFIG_AT91SAM9X5)
/* plla divisor by 2 */
gd->arch.plla_rate_hz /= (1 << ((mckr & 1 << 12) >> 12));
#endif
gd->arch.mck_rate_hz = at91_css_to_rate(mckr & AT91_PMC_MCKR_CSS_MASK);
freq = gd->arch.mck_rate_hz;
#if defined(CONFIG_AT91SAM9X5)
/* different in prescale on at91sam9x5 */
freq /= (1 << ((mckr & AT91_PMC_MCKR_PRES_MASK) >> 4));
#else
freq /= (1 << ((mckr & AT91_PMC_MCKR_PRES_MASK) >> 2)); /* prescale */
#endif
#if defined(CONFIG_AT91SAM9G20)
/* mdiv ; (x >> 7) = ((x >> 8) * 2) */
gd->arch.mck_rate_hz = (mckr & AT91_PMC_MCKR_MDIV_MASK) ?
freq / ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 7) : freq;
if (mckr & AT91_PMC_MCKR_MDIV_MASK)
freq /= 2; /* processor clock division */
#elif defined(CONFIG_AT91SAM9G45) || defined(CONFIG_AT91SAM9M10G45) \
|| defined(CONFIG_AT91SAM9N12) || defined(CONFIG_AT91SAM9X5)
/* mdiv <==> divisor
* 0 <==> 1
* 1 <==> 2
* 2 <==> 4
* 3 <==> 3
*/
gd->arch.mck_rate_hz = (mckr & AT91_PMC_MCKR_MDIV_MASK) ==
(AT91_PMC_MCKR_MDIV_2 | AT91_PMC_MCKR_MDIV_4)
? freq / 3
: freq / (1 << ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 8));
#else
gd->arch.mck_rate_hz = freq /
(1 << ((mckr & AT91_PMC_MCKR_MDIV_MASK) >> 8));
#endif
gd->arch.cpu_clk_rate_hz = freq;
return 0;
}
#if !defined(AT91_PLL_LOCK_TIMEOUT)
#define AT91_PLL_LOCK_TIMEOUT 1000000
#endif
void at91_plla_init(u32 pllar)
{
struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
writel(pllar, &pmc->pllar);
while (!(readl(&pmc->sr) & AT91_PMC_LOCKA))
;
}
void at91_pllb_init(u32 pllbr)
{
struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
writel(pllbr, &pmc->pllbr);
while (!(readl(&pmc->sr) & AT91_PMC_LOCKB))
;
}
void at91_mck_init(u32 mckr)
{
struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
u32 tmp;
tmp = readl(&pmc->mckr);
tmp &= ~AT91_PMC_MCKR_PRES_MASK;
tmp |= mckr & AT91_PMC_MCKR_PRES_MASK;
writel(tmp, &pmc->mckr);
while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
;
tmp = readl(&pmc->mckr);
tmp &= ~AT91_PMC_MCKR_MDIV_MASK;
tmp |= mckr & AT91_PMC_MCKR_MDIV_MASK;
writel(tmp, &pmc->mckr);
while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
;
tmp = readl(&pmc->mckr);
tmp &= ~AT91_PMC_MCKR_PLLADIV_MASK;
tmp |= mckr & AT91_PMC_MCKR_PLLADIV_MASK;
writel(tmp, &pmc->mckr);
while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
;
tmp = readl(&pmc->mckr);
tmp &= ~AT91_PMC_MCKR_CSS_MASK;
tmp |= mckr & AT91_PMC_MCKR_CSS_MASK;
writel(tmp, &pmc->mckr);
while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
;
}
int at91_pllb_clk_enable(u32 pllbr)
{
struct at91_pmc *pmc = (at91_pmc_t *)ATMEL_BASE_PMC;
ulong start_time, tmp_time;
start_time = get_timer(0);
writel(pllbr, &pmc->pllbr);
while ((readl(&pmc->sr) & AT91_PMC_LOCKB) != AT91_PMC_LOCKB) {
tmp_time = get_timer(0);
if ((tmp_time - start_time) > EN_PLLB_TIMEOUT) {
printf("ERROR: failed to enable PLLB\n");
return -1;
}
}
return 0;
}
int at91_pllb_clk_disable(void)
{
struct at91_pmc *pmc = (at91_pmc_t *)ATMEL_BASE_PMC;
ulong start_time, tmp_time;
start_time = get_timer(0);
writel(0, &pmc->pllbr);
while ((readl(&pmc->sr) & AT91_PMC_LOCKB) != 0) {
tmp_time = get_timer(0);
if ((tmp_time - start_time) > EN_PLLB_TIMEOUT) {
printf("ERROR: failed to disable PLLB\n");
return -1;
}
}
return 0;
}
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