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.fat...@pengutronix.de>
---
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
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