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/drivers/timer/altera_timer.c

@@ -0,0 +1,99 @@
+/*
+ * (C) Copyright 2000-2002
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
+ * Scott McNutt <smcnutt@psyent.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <timer.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* control register */
+#define ALTERA_TIMER_CONT	BIT(1)	/* Continuous mode */
+#define ALTERA_TIMER_START	BIT(2)	/* Start timer */
+#define ALTERA_TIMER_STOP	BIT(3)	/* Stop timer */
+
+struct altera_timer_regs {
+	u32	status;		/* Timer status reg */
+	u32	control;	/* Timer control reg */
+	u32	periodl;	/* Timeout period low */
+	u32	periodh;	/* Timeout period high */
+	u32	snapl;		/* Snapshot low */
+	u32	snaph;		/* Snapshot high */
+};
+
+struct altera_timer_platdata {
+	struct altera_timer_regs *regs;
+};
+
+static int altera_timer_get_count(struct udevice *dev, u64 *count)
+{
+	struct altera_timer_platdata *plat = dev->platdata;
+	struct altera_timer_regs *const regs = plat->regs;
+	u32 val;
+
+	/* Trigger update */
+	writel(0x0, &regs->snapl);
+
+	/* Read timer value */
+	val = readl(&regs->snapl) & 0xffff;
+	val |= (readl(&regs->snaph) & 0xffff) << 16;
+	*count = timer_conv_64(~val);
+
+	return 0;
+}
+
+static int altera_timer_probe(struct udevice *dev)
+{
+	struct altera_timer_platdata *plat = dev->platdata;
+	struct altera_timer_regs *const regs = plat->regs;
+
+	writel(0, &regs->status);
+	writel(0, &regs->control);
+	writel(ALTERA_TIMER_STOP, &regs->control);
+
+	writel(0xffff, &regs->periodl);
+	writel(0xffff, &regs->periodh);
+	writel(ALTERA_TIMER_CONT | ALTERA_TIMER_START, &regs->control);
+
+	return 0;
+}
+
+static int altera_timer_ofdata_to_platdata(struct udevice *dev)
+{
+	struct altera_timer_platdata *plat = dev_get_platdata(dev);
+
+	plat->regs = map_physmem(dev_get_addr(dev),
+				 sizeof(struct altera_timer_regs),
+				 MAP_NOCACHE);
+
+	return 0;
+}
+
+static const struct timer_ops altera_timer_ops = {
+	.get_count = altera_timer_get_count,
+};
+
+static const struct udevice_id altera_timer_ids[] = {
+	{ .compatible = "altr,timer-1.0" },
+	{}
+};
+
+U_BOOT_DRIVER(altera_timer) = {
+	.name	= "altera_timer",
+	.id	= UCLASS_TIMER,
+	.of_match = altera_timer_ids,
+	.ofdata_to_platdata = altera_timer_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct altera_timer_platdata),
+	.probe = altera_timer_probe,
+	.ops	= &altera_timer_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};