u-boot/arch/arm/mach-at91/armv7/clock.c

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/*
* [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>
* Copyright (C) 2013 Bo Shen <voice.shen@atmel.com>
* Copyright (C) 2015 Wenyou Yang <wenyou.yang@atmel.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <linux/errno.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
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;
}
return 0;
}
static u32 at91_pll_rate(u32 freq, u32 reg)
{
unsigned mul, div;
div = reg & 0xff;
mul = (reg >> 18) & 0x7f;
if (div && mul) {
freq /= div;
freq *= mul + 1;
} else {
freq = 0;
}
return freq;
}
int at91_clock_init(unsigned long main_clock)
{
unsigned freq, mckr;
struct at91_pmc *pmc = (struct at91_pmc *)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));
/*
* MCK and CPU derive from one of those primary clocks.
* For now, assume this parentage won't change.
*/
mckr = readl(&pmc->mckr);
/* plla divisor by 2 */
if (mckr & (1 << 12))
gd->arch.plla_rate_hz >>= 1;
gd->arch.mck_rate_hz = at91_css_to_rate(mckr & AT91_PMC_MCKR_CSS_MASK);
freq = gd->arch.mck_rate_hz;
/* prescale */
freq >>= mckr & AT91_PMC_MCKR_PRES_MASK;
switch (mckr & AT91_PMC_MCKR_MDIV_MASK) {
case AT91_PMC_MCKR_MDIV_2:
gd->arch.mck_rate_hz = freq / 2;
break;
case AT91_PMC_MCKR_MDIV_3:
gd->arch.mck_rate_hz = freq / 3;
break;
case AT91_PMC_MCKR_MDIV_4:
gd->arch.mck_rate_hz = freq / 4;
break;
default:
break;
}
gd->arch.cpu_clk_rate_hz = freq;
return 0;
}
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 | AT91_PMC_MCKRDY)))
;
}
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_CSS_MASK |
AT91_PMC_MCKR_PRES_MASK |
AT91_PMC_MCKR_MDIV_MASK |
AT91_PMC_MCKR_PLLADIV_2);
#ifdef CPU_HAS_H32MXDIV
tmp &= ~AT91_PMC_MCKR_H32MXDIV;
#endif
tmp |= mckr & (AT91_PMC_MCKR_CSS_MASK |
AT91_PMC_MCKR_PRES_MASK |
AT91_PMC_MCKR_MDIV_MASK |
AT91_PMC_MCKR_PLLADIV_2);
#ifdef CPU_HAS_H32MXDIV
tmp |= mckr & AT91_PMC_MCKR_H32MXDIV;
#endif
writel(tmp, &pmc->mckr);
while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
;
}
int at91_enable_periph_generated_clk(u32 id, u32 clk_source, u32 div)
{
struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
u32 regval, status;
u32 timeout = 1000;
if (id > AT91_PMC_PCR_PID_MASK)
return -EINVAL;
if (div > 0xff)
return -EINVAL;
if (clk_source == GCK_CSS_UPLL_CLK) {
if (at91_upll_clk_enable())
return -ENODEV;
}
writel(id, &pmc->pcr);
regval = readl(&pmc->pcr);
regval &= ~AT91_PMC_PCR_GCKCSS;
regval &= ~AT91_PMC_PCR_GCKDIV;
switch (clk_source) {
case GCK_CSS_SLOW_CLK:
regval |= AT91_PMC_PCR_GCKCSS_SLOW_CLK;
break;
case GCK_CSS_MAIN_CLK:
regval |= AT91_PMC_PCR_GCKCSS_MAIN_CLK;
break;
case GCK_CSS_PLLA_CLK:
regval |= AT91_PMC_PCR_GCKCSS_PLLA_CLK;
break;
case GCK_CSS_UPLL_CLK:
regval |= AT91_PMC_PCR_GCKCSS_UPLL_CLK;
break;
case GCK_CSS_MCK_CLK:
regval |= AT91_PMC_PCR_GCKCSS_MCK_CLK;
break;
case GCK_CSS_AUDIO_CLK:
regval |= AT91_PMC_PCR_GCKCSS_AUDIO_CLK;
break;
default:
printf("Error GCK clock source selection!\n");
return -EINVAL;
}
regval |= AT91_PMC_PCR_CMD_WRITE |
AT91_PMC_PCR_GCKDIV_(div) |
AT91_PMC_PCR_GCKEN;
writel(regval, &pmc->pcr);
do {
udelay(1);
status = readl(&pmc->sr);
} while ((!!(--timeout)) && (!(status & AT91_PMC_GCKRDY)));
if (!timeout)
printf("Timeout waiting for GCK ready!\n");
return 0;
}
u32 at91_get_periph_generated_clk(u32 id)
{
struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
u32 regval, clk_source, div;
u32 freq;
if (id > AT91_PMC_PCR_PID_MASK)
return 0;
writel(id, &pmc->pcr);
regval = readl(&pmc->pcr);
clk_source = regval & AT91_PMC_PCR_GCKCSS;
switch (clk_source) {
case AT91_PMC_PCR_GCKCSS_SLOW_CLK:
freq = CONFIG_SYS_AT91_SLOW_CLOCK;
break;
case AT91_PMC_PCR_GCKCSS_MAIN_CLK:
freq = gd->arch.main_clk_rate_hz;
break;
case AT91_PMC_PCR_GCKCSS_PLLA_CLK:
freq = gd->arch.plla_rate_hz;
break;
case AT91_PMC_PCR_GCKCSS_UPLL_CLK:
freq = AT91_UTMI_PLL_CLK_FREQ;
break;
case AT91_PMC_PCR_GCKCSS_MCK_CLK:
freq = gd->arch.mck_rate_hz;
break;
default:
printf("Improper GCK clock source selection!\n");
freq = 0;
break;
}
div = ((regval & AT91_PMC_PCR_GCKDIV) >> AT91_PMC_PCR_GCKDIV_OFFSET);
div += 1;
return freq / div;
}