ARM: atmel: add sama5d3xek support

Add sama5d3xek support with following feature
  - boot from NAND flash, PMECC support, 4bit ECC @ 512 bytes sector
  - boot from SPI flash support
  - boot from SD card support
  - LCD support
  - EMAC support
  - USB OHCI support

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>

6 files changed, 649 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv7/at91/Makefile b/arch/arm/cpu/armv7/at91/Makefile
new file mode 100644
index 0000000..040c67d
--- /dev/null
+++ b/arch/arm/cpu/armv7/at91/Makefile
@@ -0,0 +1,52 @@
+#
+# (C) Copyright 2000-2008
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# (C) Copyright 2013
+# Bo Shen <voice.shen@atmel.com>
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# 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.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB	= $(obj)lib$(SOC).o
+
+COBJS-$(CONFIG_SAMA5D3)	+= sama5d3_devices.o
+COBJS-y += clock.o
+COBJS-y += cpu.o
+COBJS-y += reset.o
+COBJS-y += timer.o
+
+SRCS    := $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
+OBJS    := $(addprefix $(obj),$(SOBJS-y) $(COBJS-y))
+
+all:	$(obj).depend $(LIB)
+
+$(LIB):	$(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/arch/arm/cpu/armv7/at91/clock.c b/arch/arm/cpu/armv7/at91/clock.c
new file mode 100644
index 0000000..624b52c
--- /dev/null
+++ b/arch/arm/cpu/armv7/at91/clock.c
@@ -0,0 +1,125 @@
+/*
+ * [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>
+ *
+ * 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 <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
+
+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_periph_clk_enable(int id)
+{
+	struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
+
+	if (id > 31)
+		writel(1 << (id - 32), &pmc->pcer1);
+	else
+		writel(1 << id, &pmc->pcer);
+}
diff --git a/arch/arm/cpu/armv7/at91/cpu.c b/arch/arm/cpu/armv7/at91/cpu.c
new file mode 100644
index 0000000..3df6143
--- /dev/null
+++ b/arch/arm/cpu/armv7/at91/cpu.c
@@ -0,0 +1,90 @@
+/*
+ * (C) Copyright 2010
+ * Reinhard Meyer, reinhard.meyer@emk-elektronik.de
+ * (C) Copyright 2009
+ * Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
+ * (C) Copyright 2013
+ * Bo Shen <voice.shen@atmel.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/at91_dbu.h>
+#include <asm/arch/at91_pmc.h>
+#include <asm/arch/at91_pit.h>
+#include <asm/arch/at91_gpbr.h>
+#include <asm/arch/clk.h>
+
+#ifndef CONFIG_SYS_AT91_MAIN_CLOCK
+#define CONFIG_SYS_AT91_MAIN_CLOCK 0
+#endif
+
+int arch_cpu_init(void)
+{
+	return at91_clock_init(CONFIG_SYS_AT91_MAIN_CLOCK);
+}
+
+void arch_preboot_os(void)
+{
+	ulong cpiv;
+	at91_pit_t *pit = (at91_pit_t *)ATMEL_BASE_PIT;
+
+	cpiv = AT91_PIT_MR_PIV_MASK(readl(&pit->piir));
+
+	/*
+	 * Disable PITC
+	 * Add 0x1000 to current counter to stop it faster
+	 * without waiting for wrapping back to 0
+	 */
+	writel(cpiv + 0x1000, &pit->mr);
+}
+
+#if defined(CONFIG_DISPLAY_CPUINFO)
+int print_cpuinfo(void)
+{
+	char buf[32];
+
+	printf("CPU: %s\n", get_cpu_name());
+	printf("Crystal frequency: %8s MHz\n",
+	       strmhz(buf, get_main_clk_rate()));
+	printf("CPU clock        : %8s MHz\n",
+	       strmhz(buf, get_cpu_clk_rate()));
+	printf("Master clock     : %8s MHz\n",
+	       strmhz(buf, get_mck_clk_rate()));
+
+	return 0;
+}
+#endif
+
+void enable_caches(void)
+{
+}
+
+unsigned int get_chip_id(void)
+{
+	return readl(ATMEL_BASE_DBGU + AT91_DBU_CIDR) & ~AT91_DBU_CIDR_MASK;
+}
+
+unsigned int get_extension_chip_id(void)
+{
+	return readl(ATMEL_BASE_DBGU + AT91_DBU_EXID);
+}
diff --git a/arch/arm/cpu/armv7/at91/reset.c b/arch/arm/cpu/armv7/at91/reset.c
new file mode 100644
index 0000000..b9f83d9
--- /dev/null
+++ b/arch/arm/cpu/armv7/at91/reset.c
@@ -0,0 +1,47 @@
+/*
+ * (C) Copyright 2007-2008
+ * Stelian Pop <stelian@popies.net>
+ * Lead Tech Design <www.leadtechdesign.com>
+ *
+ * (C) Copyright 2013
+ * Bo Shen <voice.shen@atmel.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/at91_rstc.h>
+
+/* Reset the cpu by telling the reset controller to do so */
+void reset_cpu(ulong ignored)
+{
+	at91_rstc_t *rstc = (at91_rstc_t *)ATMEL_BASE_RSTC;
+
+	writel(AT91_RSTC_KEY
+		| AT91_RSTC_CR_PROCRST	/* Processor Reset */
+		| AT91_RSTC_CR_PERRST	/* Peripheral Reset */
+#ifdef CONFIG_AT91RESET_EXTRST
+		| AT91_RSTC_CR_EXTRST	/* External Reset (assert nRST pin) */
+#endif
+		, &rstc->cr);
+	/* never reached */
+	do { } while (1);
+}
diff --git a/arch/arm/cpu/armv7/at91/sama5d3_devices.c b/arch/arm/cpu/armv7/at91/sama5d3_devices.c
new file mode 100644
index 0000000..acf8b43
--- /dev/null
+++ b/arch/arm/cpu/armv7/at91/sama5d3_devices.c
@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2012-2013 Atmel Corporation
+ * Bo Shen <voice.shen@atmel.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/arch/sama5d3.h>
+#include <asm/arch/at91_common.h>
+#include <asm/arch/at91_pmc.h>
+#include <asm/arch/clk.h>
+#include <asm/arch/gpio.h>
+#include <asm/io.h>
+
+unsigned int has_emac()
+{
+	return cpu_is_sama5d31() || cpu_is_sama5d35();
+}
+
+unsigned int has_gmac()
+{
+	return !cpu_is_sama5d31();
+}
+
+unsigned int has_lcdc()
+{
+	return !cpu_is_sama5d35();
+}
+
+char *get_cpu_name()
+{
+	unsigned int extension_id = get_extension_chip_id();
+
+	if (cpu_is_sama5d3())
+		switch (extension_id) {
+		case ARCH_EXID_SAMA5D31:
+			return "SAMA5D31";
+		case ARCH_EXID_SAMA5D33:
+			return "SAMA5D33";
+		case ARCH_EXID_SAMA5D34:
+			return "SAMA5D34";
+		case ARCH_EXID_SAMA5D35:
+			return "SAMA5D35";
+		default:
+			return "Unknown CPU type";
+		}
+	else
+		return "Unknown CPU type";
+}
+
+void at91_serial0_hw_init(void)
+{
+	at91_set_a_periph(AT91_PIO_PORTD, 18, 1);	/* TXD0 */
+	at91_set_a_periph(AT91_PIO_PORTD, 17, 0);	/* RXD0 */
+
+	/* Enable clock */
+	at91_periph_clk_enable(ATMEL_ID_USART0);
+}
+
+void at91_serial1_hw_init(void)
+{
+	at91_set_a_periph(AT91_PIO_PORTB, 29, 1);	/* TXD1 */
+	at91_set_a_periph(AT91_PIO_PORTB, 28, 0);	/* RXD1 */
+
+	/* Enable clock */
+	at91_periph_clk_enable(ATMEL_ID_USART1);
+}
+
+void at91_serial2_hw_init(void)
+{
+	at91_set_b_periph(AT91_PIO_PORTE, 26, 1);	/* TXD2 */
+	at91_set_b_periph(AT91_PIO_PORTE, 25, 0);	/* RXD2 */
+
+	/* Enable clock */
+	at91_periph_clk_enable(ATMEL_ID_USART2);
+}
+
+void at91_seriald_hw_init(void)
+{
+	at91_set_a_periph(AT91_PIO_PORTB, 31, 1);	/* DTXD */
+	at91_set_a_periph(AT91_PIO_PORTB, 30, 0);	/* DRXD */
+
+	/* Enable clock */
+	at91_periph_clk_enable(ATMEL_ID_SYS);
+}
+
+#if defined(CONFIG_ATMEL_SPI)
+void at91_spi0_hw_init(unsigned long cs_mask)
+{
+	at91_set_a_periph(AT91_PIO_PORTD, 10, 0);       /* SPI0_MISO */
+	at91_set_a_periph(AT91_PIO_PORTD, 11, 0);       /* SPI0_MOSI */
+	at91_set_a_periph(AT91_PIO_PORTD, 12, 0);       /* SPI0_SPCK */
+
+	if (cs_mask & (1 << 0))
+		at91_set_pio_output(AT91_PIO_PORTD, 13, 1);
+	if (cs_mask & (1 << 1))
+		at91_set_pio_output(AT91_PIO_PORTD, 14, 1);
+	if (cs_mask & (1 << 2))
+		at91_set_pio_output(AT91_PIO_PORTD, 15, 1);
+	if (cs_mask & (1 << 3))
+		at91_set_pio_output(AT91_PIO_PORTD, 16, 1);
+
+	/* Enable clock */
+	at91_periph_clk_enable(ATMEL_ID_SPI0);
+}
+#endif
+
+#ifdef CONFIG_GENERIC_ATMEL_MCI
+void at91_mci_hw_init(void)
+{
+	at91_set_a_periph(AT91_PIO_PORTD, 0, 0);	/* MCI0 CMD */
+	at91_set_a_periph(AT91_PIO_PORTD, 1, 0);	/* MCI0 DA0 */
+	at91_set_a_periph(AT91_PIO_PORTD, 2, 0);	/* MCI0 DA1 */
+	at91_set_a_periph(AT91_PIO_PORTD, 3, 0);        /* MCI0 DA2 */
+	at91_set_a_periph(AT91_PIO_PORTD, 4, 0);        /* MCI0 DA3 */
+#ifdef CONFIG_ATMEL_MCI_8BIT
+	at91_set_a_periph(AT91_PIO_PORTD, 5, 0);        /* MCI0 DA4 */
+	at91_set_a_periph(AT91_PIO_PORTD, 6, 0);        /* MCI0 DA5 */
+	at91_set_a_periph(AT91_PIO_PORTD, 7, 0);        /* MCI0 DA6 */
+	at91_set_a_periph(AT91_PIO_PORTD, 8, 0);        /* MCI0 DA7 */
+#endif
+	at91_set_a_periph(AT91_PIO_PORTD, 9, 0);        /* MCI0 CLK */
+
+	/* Enable clock */
+	at91_periph_clk_enable(ATMEL_ID_MCI0);
+}
+#endif
+
+#ifdef CONFIG_MACB
+void at91_macb_hw_init(void)
+{
+	at91_set_a_periph(AT91_PIO_PORTC, 7, 0);	/* ETXCK_EREFCK */
+	at91_set_a_periph(AT91_PIO_PORTC, 5, 0);	/* ERXDV */
+	at91_set_a_periph(AT91_PIO_PORTC, 2, 0);	/* ERX0 */
+	at91_set_a_periph(AT91_PIO_PORTC, 3, 0);	/* ERX1 */
+	at91_set_a_periph(AT91_PIO_PORTC, 6, 0);	/* ERXER */
+	at91_set_a_periph(AT91_PIO_PORTC, 4, 0);	/* ETXEN */
+	at91_set_a_periph(AT91_PIO_PORTC, 0, 0);	/* ETX0 */
+	at91_set_a_periph(AT91_PIO_PORTC, 1, 0);	/* ETX1 */
+	at91_set_a_periph(AT91_PIO_PORTC, 9, 0);	/* EMDIO */
+	at91_set_a_periph(AT91_PIO_PORTC, 8, 0);	/* EMDC */
+
+	/* Enable clock */
+	at91_periph_clk_enable(ATMEL_ID_EMAC);
+}
+#endif
+
+#ifdef CONFIG_LCD
+void at91_lcd_hw_init(void)
+{
+	at91_set_a_periph(AT91_PIO_PORTA, 24, 0);	/* LCDPWM */
+	at91_set_a_periph(AT91_PIO_PORTA, 25, 0);	/* LCDDISP */
+	at91_set_a_periph(AT91_PIO_PORTA, 26, 0);	/* LCDVSYNC */
+	at91_set_a_periph(AT91_PIO_PORTA, 27, 0);	/* LCDHSYNC */
+	at91_set_a_periph(AT91_PIO_PORTA, 28, 0);	/* LCDDOTCK */
+	at91_set_a_periph(AT91_PIO_PORTA, 29, 0);	/* LCDDEN */
+
+	/* The lower 16-bit of LCD only available on Port A */
+	at91_set_a_periph(AT91_PIO_PORTA,  0, 0);	/* LCDD0 */
+	at91_set_a_periph(AT91_PIO_PORTA,  1, 0);	/* LCDD1 */
+	at91_set_a_periph(AT91_PIO_PORTA,  2, 0);	/* LCDD2 */
+	at91_set_a_periph(AT91_PIO_PORTA,  3, 0);	/* LCDD3 */
+	at91_set_a_periph(AT91_PIO_PORTA,  4, 0);	/* LCDD4 */
+	at91_set_a_periph(AT91_PIO_PORTA,  5, 0);	/* LCDD5 */
+	at91_set_a_periph(AT91_PIO_PORTA,  6, 0);	/* LCDD6 */
+	at91_set_a_periph(AT91_PIO_PORTA,  7, 0);	/* LCDD7 */
+	at91_set_a_periph(AT91_PIO_PORTA,  8, 0);	/* LCDD8 */
+	at91_set_a_periph(AT91_PIO_PORTA,  9, 0);	/* LCDD9 */
+	at91_set_a_periph(AT91_PIO_PORTA, 10, 0);	/* LCDD10 */
+	at91_set_a_periph(AT91_PIO_PORTA, 11, 0);	/* LCDD11 */
+	at91_set_a_periph(AT91_PIO_PORTA, 12, 0);	/* LCDD12 */
+	at91_set_a_periph(AT91_PIO_PORTA, 13, 0);	/* LCDD13 */
+	at91_set_a_periph(AT91_PIO_PORTA, 14, 0);	/* LCDD14 */
+	at91_set_a_periph(AT91_PIO_PORTA, 15, 0);	/* LCDD15 */
+
+	/* Enable clock */
+	at91_periph_clk_enable(ATMEL_ID_LCDC);
+}
+#endif
diff --git a/arch/arm/cpu/armv7/at91/timer.c b/arch/arm/cpu/armv7/at91/timer.c
new file mode 100644
index 0000000..b3a450f
--- /dev/null
+++ b/arch/arm/cpu/armv7/at91/timer.c
@@ -0,0 +1,139 @@
+/*
+ * (C) Copyright 2007-2008
+ * Stelian Pop <stelian@popies.net>
+ * Lead Tech Design <www.leadtechdesign.com>
+ *
+ * (C) Copyright 2013
+ * Bo Shen <voice.shen@atmel.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+#include <asm/arch/at91_pit.h>
+#include <asm/arch/at91_pmc.h>
+#include <asm/arch/clk.h>
+#include <div64.h>
+
+#if !defined(CONFIG_AT91FAMILY)
+# error You need to define CONFIG_AT91FAMILY in your board config!
+#endif
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * We're using the SAMA5D3x PITC in 32 bit mode, by
+ * setting the 20 bit counter period to its maximum (0xfffff).
+ * (See the relevant data sheets to understand that this really works)
+ *
+ * We do also mimic the typical powerpc way of incrementing
+ * two 32 bit registers called tbl and tbu.
+ *
+ * Those registers increment at 1/16 the main clock rate.
+ */
+
+#define TIMER_LOAD_VAL	0xfffff
+
+static inline unsigned long long tick_to_time(unsigned long long tick)
+{
+	tick *= CONFIG_SYS_HZ;
+	do_div(tick, gd->arch.timer_rate_hz);
+
+	return tick;
+}
+
+static inline unsigned long long usec_to_tick(unsigned long long usec)
+{
+	usec *= gd->arch.timer_rate_hz;
+	do_div(usec, 1000000);
+
+	return usec;
+}
+
+/*
+ * Use the PITC in full 32 bit incrementing mode
+ */
+int timer_init(void)
+{
+	at91_pit_t *pit = (at91_pit_t *)ATMEL_BASE_PIT;
+
+	/* Enable PITC Clock */
+	at91_periph_clk_enable(ATMEL_ID_SYS);
+
+	/* Enable PITC */
+	writel(TIMER_LOAD_VAL | AT91_PIT_MR_EN , &pit->mr);
+
+	gd->arch.timer_rate_hz = gd->arch.mck_rate_hz / 16;
+	gd->arch.tbu = 0;
+	gd->arch.tbl = 0;
+
+	return 0;
+}
+
+/*
+ * Get the current 64 bit timer tick count
+ */
+unsigned long long get_ticks(void)
+{
+	at91_pit_t *pit = (at91_pit_t *)ATMEL_BASE_PIT;
+
+	ulong now = readl(&pit->piir);
+
+	/* increment tbu if tbl has rolled over */
+	if (now < gd->arch.tbl)
+		gd->arch.tbu++;
+	gd->arch.tbl = now;
+	return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
+}
+
+void __udelay(unsigned long usec)
+{
+	unsigned long long start;
+	ulong tmo;
+
+	start = get_ticks();		/* get current timestamp */
+	tmo = usec_to_tick(usec);	/* convert usecs to ticks */
+	while ((get_ticks() - start) < tmo)
+		;			/* loop till time has passed */
+}
+
+/*
+ * get_timer(base) can be used to check for timeouts or
+ * to measure elasped time relative to an event:
+ *
+ * ulong start_time = get_timer(0) sets start_time to the current
+ * time value.
+ * get_timer(start_time) returns the time elapsed since then.
+ *
+ * The time is used in CONFIG_SYS_HZ units!
+ */
+ulong get_timer(ulong base)
+{
+	return tick_to_time(get_ticks()) - base;
+}
+
+/*
+ * Return the number of timer ticks per second.
+ */
+ulong get_tbclk(void)
+{
+	return gd->arch.timer_rate_hz;
+}