For use by future at91 first stage bootloaders, this commit imports https://github.com/linux4sam/at91bootstrap/blob/v3.8.12/driver/pmc.c to do the low level clock initialization. Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> --- arch/arm/mach-at91/Makefile | 1 + .../include/mach/at91_lowlevel_clock.h | 30 ++++ arch/arm/mach-at91/include/mach/at91_pmc.h | 5 +- arch/arm/mach-at91/lowlevel_clock.c | 164 ++++++++++++++++++ 4 files changed, 199 insertions(+), 1 deletion(-) create mode 100644 arch/arm/mach-at91/include/mach/at91_lowlevel_clock.h create mode 100644 arch/arm/mach-at91/lowlevel_clock.c diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile index d81683ac121a..7c4c58b080a1 100644 --- a/arch/arm/mach-at91/Makefile +++ b/arch/arm/mach-at91/Makefile @@ -1,4 +1,5 @@ obj-y += setup.o +pbl-y += lowlevel_clock.o ifeq ($(CONFIG_COMMON_CLK_OF_PROVIDER),) obj-y += clock.o diff --git a/arch/arm/mach-at91/include/mach/at91_lowlevel_clock.h b/arch/arm/mach-at91/include/mach/at91_lowlevel_clock.h new file mode 100644 index 000000000000..5b32cfdc69bf --- /dev/null +++ b/arch/arm/mach-at91/include/mach/at91_lowlevel_clock.h @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: BSD-1-Clause +/* + * Copyright (c) 2006, Atmel Corporation + */ + +#ifndef AT91_LOWLEVEL_CLOCK_H +#define AT91_LOWLEVEL_CLOCK_H + +#include <errno.h> +#include <asm/io.h> +#include <mach/at91_pmc.h> + +void at91_lowlevel_clock_init(void __iomem *pmc_base); +void at91_pmc_cfg_mck(void __iomem *pmc_base, unsigned int pmc_mckr); +static inline int at91_pmc_enable_periph_clock(void __iomem *pmc_base, + unsigned periph_id) +{ + u32 mask = 0x01 << (periph_id % 32); + + if ((periph_id / 32) == 1) + __raw_writel(mask, pmc_base + AT91_PMC_PCER1); + else if ((periph_id / 32) == 0) + __raw_writel(mask, pmc_base + AT91_PMC_PCER); + else + return -EINVAL; + + return 0; +} + +#endif diff --git a/arch/arm/mach-at91/include/mach/at91_pmc.h b/arch/arm/mach-at91/include/mach/at91_pmc.h index bbbd497afaed..0f13e4f4d391 100644 --- a/arch/arm/mach-at91/include/mach/at91_pmc.h +++ b/arch/arm/mach-at91/include/mach/at91_pmc.h @@ -50,7 +50,9 @@ #define AT91_PMC_OSCBYPASS (1 << 1) /* Oscillator Bypass */ #define AT91_PMC_MOSCRCEN (1 << 3) /* Main On-Chip RC Oscillator Enable [some SAM9] */ #define AT91_PMC_OSCOUNT (0xff << 8) /* Main Oscillator Start-up Time */ -#define AT91_PMC_KEY (0x37 << 16) /* MOR Writing Key */ +#define AT91_PMC_OSCOUNT_(x) ((x) << 8) +#define AT91_PMC_KEY_MASK (0xff << 16) /* MOR Writing Key */ +#define AT91_PMC_KEY (0x37 << 16) #define AT91_PMC_MOSCSEL (1 << 24) /* Main Oscillator Selection [some SAM9] */ #define AT91_PMC_CFDEN (1 << 25) /* Clock Failure Detector Enable [some SAM9] */ @@ -133,6 +135,7 @@ #define AT91_PMC_CSSMCK_MCK (1 << 8) #define AT91_PMC_IER 0x60 /* Interrupt Enable Register */ +#define AT91_PMC_MOSCXTS (1 << 0) /* Oscillator Startup Time */ #define AT91_PMC_IDR 0x64 /* Interrupt Disable Register */ #define AT91_PMC_SR 0x68 /* Status Register */ #define AT91_PMC_MOSCS (1 << 0) /* MOSCS Flag */ diff --git a/arch/arm/mach-at91/lowlevel_clock.c b/arch/arm/mach-at91/lowlevel_clock.c new file mode 100644 index 000000000000..c974409a99fc --- /dev/null +++ b/arch/arm/mach-at91/lowlevel_clock.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: BSD-1-Clause +/* + * Copyright (c) 2006, Atmel Corporation + */ + +#include <common.h> +#include <mach/at91_lowlevel_clock.h> +#include <mach/at91_pmc.h> + +#define at91_pmc_write(off, val) writel(val, pmc_base + off) +#define at91_pmc_read(off) readl(pmc_base + off) + +void at91_lowlevel_clock_init(void __iomem *pmc_base) +{ + unsigned long tmp; + + /* + * Switch the master clock to the slow clock without modifying other + * parameters. It is assumed that ROM code set H32MXDIV, PLLADIV2, + * PCK_DIV3. + */ + tmp = at91_pmc_read(AT91_PMC_MCKR); + tmp &= ~AT91_PMC_ALT_PCKR_CSS; + tmp |= AT91_PMC_CSS_SLOW; + at91_pmc_write(AT91_PMC_MCKR, tmp); + + while (!(at91_pmc_read(AT91_PMC_SR) & AT91_PMC_MCKRDY)) + ; + + if (IS_ENABLED(CONFIG_SOC_AT91SAM9X5) || IS_ENABLED(CONFIG_SOC_AT91SAM9N12) + || IS_ENABLED(CONFIG_SOC_SAMA5)) { + /* + * Enable the Main Crystal Oscillator + * tST_max = 2ms + * Startup Time: 32768 * 2ms / 8 = 8 + */ + tmp = at91_pmc_read(AT91_CKGR_MOR); + tmp &= ~AT91_PMC_OSCOUNT; + tmp &= ~AT91_PMC_KEY_MASK; + tmp |= AT91_PMC_MOSCEN; + tmp |= AT91_PMC_OSCOUNT_(8); + tmp |= AT91_PMC_KEY; + at91_pmc_write(AT91_CKGR_MOR, tmp); + + while (!(at91_pmc_read(AT91_PMC_SR) & AT91_PMC_MOSCS)) + ; + + /* Switch from internal 12MHz RC to the Main Cristal Oscillator */ + tmp = at91_pmc_read(AT91_CKGR_MOR); + tmp &= ~AT91_PMC_OSCBYPASS; + tmp &= ~AT91_PMC_KEY_MASK; + tmp |= AT91_PMC_KEY; + at91_pmc_write(AT91_CKGR_MOR, tmp); + + tmp = at91_pmc_read(AT91_CKGR_MOR); + tmp |= AT91_PMC_MOSCSEL; + tmp &= ~AT91_PMC_KEY_MASK; + tmp |= AT91_PMC_KEY; + at91_pmc_write(AT91_CKGR_MOR, tmp); + + while (!(at91_pmc_read(AT91_PMC_SR) & AT91_PMC_MOSCSELS)) + ; + + if (!IS_ENABLED(CONFIG_ARCH_SAMA5D4)) { + /* Disable the 12MHz RC Oscillator */ + tmp = at91_pmc_read(AT91_CKGR_MOR); + tmp &= ~AT91_PMC_MOSCRCEN; + tmp &= ~AT91_PMC_KEY_MASK; + tmp |= AT91_PMC_KEY; + at91_pmc_write(AT91_CKGR_MOR, tmp); + } + + } else { + /* + * Enable the Main Crystal Oscillator + * tST_max = 2ms + * Startup Time: 32768 * 2ms / 8 = 8 + */ + tmp = at91_pmc_read(AT91_CKGR_MOR); + tmp &= ~AT91_PMC_OSCOUNT; + tmp |= AT91_PMC_MOSCEN; + tmp |= AT91_PMC_OSCOUNT_(8); + at91_pmc_write(AT91_CKGR_MOR, tmp); + + while (!(at91_pmc_read(AT91_PMC_SR) & AT91_PMC_MOSCXTS)) + ; + } + + /* After stablization, switch to Main Clock */ + if ((at91_pmc_read(AT91_PMC_MCKR) & AT91_PMC_ALT_PCKR_CSS) == AT91_PMC_CSS_SLOW) { + tmp = at91_pmc_read(AT91_PMC_MCKR); + tmp &= ~(0x1 << 13); + tmp &= ~AT91_PMC_ALT_PCKR_CSS; + tmp |= AT91_PMC_CSS_MAIN; + at91_pmc_write(AT91_PMC_MCKR, tmp); + + while (!(at91_pmc_read(AT91_PMC_SR) & AT91_PMC_MCKRDY)) + ; + + tmp &= ~AT91_PMC_PRES; + tmp |= AT91_PMC_PRES_1; + at91_pmc_write(AT91_PMC_MCKR, tmp); + + while (!(at91_pmc_read(AT91_PMC_SR) & AT91_PMC_MCKRDY)) + ; + } +} + +void at91_pmc_cfg_mck(void __iomem *pmc_base, unsigned int pmc_mckr) +{ + u32 tmp; + + /* + * Program the PRES field in the AT91_PMC_MCKR register + */ + tmp = at91_pmc_read(AT91_PMC_MCKR); + tmp &= ~(0x1 << 13); + if (IS_ENABLED(CONFIG_SOC_AT91SAM9X5) + || IS_ENABLED(CONFIG_SOC_AT91SAM9N12) + || IS_ENABLED(CONFIG_SOC_SAMA5)) { + tmp &= ~AT91_PMC_ALT_PRES; + tmp |= pmc_mckr & AT91_PMC_ALT_PRES; + } else { + tmp &= ~AT91_PMC_PRES; + tmp |= pmc_mckr & AT91_PMC_PRES; + } + at91_pmc_write(AT91_PMC_MCKR, tmp); + + /* + * Program the MDIV field in the AT91_PMC_MCKR register + */ + tmp = at91_pmc_read(AT91_PMC_MCKR); + tmp &= ~AT91_PMC_MDIV; + tmp |= pmc_mckr & AT91_PMC_MDIV; + at91_pmc_write(AT91_PMC_MCKR, tmp); + + /* + * Program the PLLADIV2 field in the AT91_PMC_MCKR register + */ + tmp = at91_pmc_read(AT91_PMC_MCKR); + tmp &= ~AT91_PMC_PLLADIV2; + tmp |= pmc_mckr & AT91_PMC_PLLADIV2; + at91_pmc_write(AT91_PMC_MCKR, tmp); + + /* + * Program the H32MXDIV field in the AT91_PMC_MCKR register + */ + tmp = at91_pmc_read(AT91_PMC_MCKR); + tmp &= ~AT91_PMC_H32MXDIV; + tmp |= pmc_mckr & AT91_PMC_H32MXDIV; + at91_pmc_write(AT91_PMC_MCKR, tmp); + + /* + * Program the CSS field in the AT91_PMC_MCKR register, + * wait for MCKRDY bit to be set in the PMC_SR register + */ + tmp = at91_pmc_read(AT91_PMC_MCKR); + tmp &= ~AT91_PMC_ALT_PCKR_CSS; + tmp |= pmc_mckr & AT91_PMC_ALT_PCKR_CSS; + at91_pmc_write(AT91_PMC_MCKR, tmp); + + while (!(at91_pmc_read(AT91_PMC_SR) & AT91_PMC_MCKRDY)) + ; +} -- 2.20.1 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
