avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/arch/arm/cpu/arm926ejs/mx27/timer.c

@@ -0,0 +1,162 @@
+/*
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Alex Zuepke <azu@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
+ *
+ * (C) Copyright 2009
+ * Ilya Yanok, Emcraft Systems Ltd, <yanok@emcraft.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <div64.h>
+#include <asm/io.h>
+#include <asm/arch/imx-regs.h>
+
+/* General purpose timers bitfields */
+#define GPTCR_SWR		(1 << 15)	/* Software reset	*/
+#define GPTCR_FRR		(1 << 8)	/* Freerun / restart	*/
+#define GPTCR_CLKSOURCE_32	(4 << 1)	/* Clock source		*/
+#define GPTCR_TEN		1		/* Timer enable		*/
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define timestamp	(gd->arch.tbl)
+#define lastinc		(gd->arch.lastinc)
+
+/*
+ * "time" is measured in 1 / CONFIG_SYS_HZ seconds,
+ * "tick" is internal timer period
+ */
+#ifdef CONFIG_MX27_TIMER_HIGH_PRECISION
+/* ~0.4% error - measured with stop-watch on 100s boot-delay */
+static inline unsigned long long tick_to_time(unsigned long long tick)
+{
+	tick *= CONFIG_SYS_HZ;
+	do_div(tick, CONFIG_MX27_CLK32);
+	return tick;
+}
+
+static inline unsigned long long time_to_tick(unsigned long long time)
+{
+	time *= CONFIG_MX27_CLK32;
+	do_div(time, CONFIG_SYS_HZ);
+	return time;
+}
+
+static inline unsigned long long us_to_tick(unsigned long long us)
+{
+	us = us * CONFIG_MX27_CLK32 + 999999;
+	do_div(us, 1000000);
+	return us;
+}
+#else
+/* ~2% error */
+#define TICK_PER_TIME	((CONFIG_MX27_CLK32 + CONFIG_SYS_HZ / 2) / \
+		CONFIG_SYS_HZ)
+#define US_PER_TICK	(1000000 / CONFIG_MX27_CLK32)
+
+static inline unsigned long long tick_to_time(unsigned long long tick)
+{
+	do_div(tick, TICK_PER_TIME);
+	return tick;
+}
+
+static inline unsigned long long time_to_tick(unsigned long long time)
+{
+	return time * TICK_PER_TIME;
+}
+
+static inline unsigned long long us_to_tick(unsigned long long us)
+{
+	us += US_PER_TICK - 1;
+	do_div(us, US_PER_TICK);
+	return us;
+}
+#endif
+
+/* nothing really to do with interrupts, just starts up a counter. */
+/* The 32768Hz 32-bit timer overruns in 131072 seconds */
+int timer_init(void)
+{
+	int i;
+	struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
+	struct pll_regs *pll = (struct pll_regs *)IMX_PLL_BASE;
+
+	/* setup GP Timer 1 */
+	writel(GPTCR_SWR, &regs->gpt_tctl);
+
+	writel(readl(&pll->pccr0) | PCCR0_GPT1_EN, &pll->pccr0);
+	writel(readl(&pll->pccr1) | PCCR1_PERCLK1_EN, &pll->pccr1);
+
+	for (i = 0; i < 100; i++)
+		writel(0, &regs->gpt_tctl); /* We have no udelay by now */
+	writel(0, &regs->gpt_tprer); /* 32Khz */
+	/* Freerun Mode, PERCLK1 input */
+	writel(readl(&regs->gpt_tctl) | GPTCR_CLKSOURCE_32 | GPTCR_FRR,
+			&regs->gpt_tctl);
+	writel(readl(&regs->gpt_tctl) | GPTCR_TEN, &regs->gpt_tctl);
+
+	return 0;
+}
+
+unsigned long long get_ticks(void)
+{
+	struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
+	ulong now = readl(&regs->gpt_tcn); /* current tick value */
+
+	if (now >= lastinc) {
+		/*
+		 * normal mode (non roll)
+		 * move stamp forward with absolut diff ticks
+		 */
+		timestamp += (now - lastinc);
+	} else {
+		/* we have rollover of incrementer */
+		timestamp += (0xFFFFFFFF - lastinc) + now;
+	}
+	lastinc = now;
+	return timestamp;
+}
+
+ulong get_timer_masked(void)
+{
+	/*
+	 * get_ticks() returns a long long (64 bit), it wraps in
+	 * 2^64 / CONFIG_MX27_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
+	 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
+	 * 5 * 10^6 days - long enough.
+	 */
+	return tick_to_time(get_ticks());
+}
+
+ulong get_timer(ulong base)
+{
+	return get_timer_masked() - base;
+}
+
+/* delay x useconds AND preserve advance timstamp value */
+void __udelay(unsigned long usec)
+{
+	unsigned long long tmp;
+	ulong tmo;
+
+	tmo = us_to_tick(usec);
+	tmp = get_ticks() + tmo;	/* get current timestamp */
+
+	while (get_ticks() < tmp)	/* loop till event */
+		 /*NOP*/;
+}
+
+ulong get_tbclk(void)
+{
+	return CONFIG_MX27_CLK32;
+}