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/rtc/i2c_rtc_emul.c

@@ -0,0 +1,236 @@
+/*
+ * Simulate an I2C real time clock
+ *
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * This is a test driver. It starts off with the current time of the machine,
+ * but also supports setting the time, using an offset from the current
+ * clock. This driver is only intended for testing, not accurate
+ * time-keeping. It does not change the system time.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <fdtdec.h>
+#include <i2c.h>
+#include <os.h>
+#include <rtc.h>
+#include <asm/rtc.h>
+#include <asm/test.h>
+
+#ifdef DEBUG
+#define debug_buffer print_buffer
+#else
+#define debug_buffer(x, ...)
+#endif
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * struct sandbox_i2c_rtc_plat_data - platform data for the RTC
+ *
+ * @base_time:		Base system time when RTC device was bound
+ * @offset:		RTC offset from current system time
+ * @use_system_time:	true to use system time, false to use @base_time
+ * @reg:		Register values
+ */
+struct sandbox_i2c_rtc_plat_data {
+	long base_time;
+	long offset;
+	bool use_system_time;
+	u8 reg[REG_COUNT];
+};
+
+struct sandbox_i2c_rtc {
+	unsigned int offset_secs;
+};
+
+long sandbox_i2c_rtc_set_offset(struct udevice *dev, bool use_system_time,
+				int offset)
+{
+	struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev);
+	long old_offset;
+
+	old_offset = plat->offset;
+	plat->use_system_time = use_system_time;
+	if (offset != -1)
+		plat->offset = offset;
+
+	return old_offset;
+}
+
+long sandbox_i2c_rtc_get_set_base_time(struct udevice *dev, long base_time)
+{
+	struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev);
+	long old_base_time;
+
+	old_base_time = plat->base_time;
+	if (base_time != -1)
+		plat->base_time = base_time;
+
+	return old_base_time;
+}
+
+static void reset_time(struct udevice *dev)
+{
+	struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev);
+	struct rtc_time now;
+
+	os_localtime(&now);
+	plat->base_time = rtc_mktime(&now);
+	plat->offset = 0;
+	plat->use_system_time = true;
+}
+
+static int sandbox_i2c_rtc_get(struct udevice *dev, struct rtc_time *time)
+{
+	struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev);
+	struct rtc_time tm_now;
+	long now;
+
+	if (plat->use_system_time) {
+		os_localtime(&tm_now);
+		now = rtc_mktime(&tm_now);
+	} else {
+		now = plat->base_time;
+	}
+
+	return rtc_to_tm(now + plat->offset, time);
+}
+
+static int sandbox_i2c_rtc_set(struct udevice *dev, const struct rtc_time *time)
+{
+	struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev);
+	struct rtc_time tm_now;
+	long now;
+
+	if (plat->use_system_time) {
+		os_localtime(&tm_now);
+		now = rtc_mktime(&tm_now);
+	} else {
+		now = plat->base_time;
+	}
+	plat->offset = rtc_mktime(time) - now;
+
+	return 0;
+}
+
+/* Update the current time in the registers */
+static int sandbox_i2c_rtc_prepare_read(struct udevice *emul)
+{
+	struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(emul);
+	struct rtc_time time;
+	int ret;
+
+	ret = sandbox_i2c_rtc_get(emul, &time);
+	if (ret)
+		return ret;
+
+	plat->reg[REG_SEC] = time.tm_sec;
+	plat->reg[REG_MIN] = time.tm_min;
+	plat->reg[REG_HOUR] = time.tm_hour;
+	plat->reg[REG_MDAY] = time.tm_mday;
+	plat->reg[REG_MON] = time.tm_mon;
+	plat->reg[REG_YEAR] = time.tm_year - 1900;
+	plat->reg[REG_WDAY] = time.tm_wday;
+
+	return 0;
+}
+
+static int sandbox_i2c_rtc_complete_write(struct udevice *emul)
+{
+	struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(emul);
+	struct rtc_time time;
+	int ret;
+
+	time.tm_sec = plat->reg[REG_SEC];
+	time.tm_min = plat->reg[REG_MIN];
+	time.tm_hour = plat->reg[REG_HOUR];
+	time.tm_mday = plat->reg[REG_MDAY];
+	time.tm_mon = plat->reg[REG_MON];
+	time.tm_year = plat->reg[REG_YEAR] + 1900;
+	time.tm_wday = plat->reg[REG_WDAY];
+
+	ret = sandbox_i2c_rtc_set(emul, &time);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int sandbox_i2c_rtc_xfer(struct udevice *emul, struct i2c_msg *msg,
+				int nmsgs)
+{
+	struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(emul);
+	uint offset = 0;
+	int ret;
+
+	debug("\n%s\n", __func__);
+	ret = sandbox_i2c_rtc_prepare_read(emul);
+	if (ret)
+		return ret;
+	for (; nmsgs > 0; nmsgs--, msg++) {
+		int len;
+		u8 *ptr;
+
+		len = msg->len;
+		debug("   %s: msg->len=%d",
+		      msg->flags & I2C_M_RD ? "read" : "write",
+		      msg->len);
+		if (msg->flags & I2C_M_RD) {
+			debug(", offset %x, len %x: ", offset, len);
+
+			/* Read the register */
+			memcpy(msg->buf, plat->reg + offset, len);
+			memset(msg->buf + len, '\xff', msg->len - len);
+			debug_buffer(0, msg->buf, 1, msg->len, 0);
+		} else if (len >= 1) {
+			ptr = msg->buf;
+			offset = *ptr++ & (REG_COUNT - 1);
+			len--;
+			debug(", set offset %x: ", offset);
+			debug_buffer(0, msg->buf, 1, msg->len, 0);
+
+			/* Write the register */
+			memcpy(plat->reg + offset, ptr, len);
+			if (offset == REG_RESET)
+				reset_time(emul);
+		}
+	}
+	ret = sandbox_i2c_rtc_complete_write(emul);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+struct dm_i2c_ops sandbox_i2c_rtc_emul_ops = {
+	.xfer = sandbox_i2c_rtc_xfer,
+};
+
+static int sandbox_i2c_rtc_bind(struct udevice *dev)
+{
+	reset_time(dev);
+
+	return 0;
+}
+
+static const struct udevice_id sandbox_i2c_rtc_ids[] = {
+	{ .compatible = "sandbox,i2c-rtc" },
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_i2c_rtc_emul) = {
+	.name		= "sandbox_i2c_rtc_emul",
+	.id		= UCLASS_I2C_EMUL,
+	.of_match	= sandbox_i2c_rtc_ids,
+	.bind		= sandbox_i2c_rtc_bind,
+	.priv_auto_alloc_size = sizeof(struct sandbox_i2c_rtc),
+	.platdata_auto_alloc_size = sizeof(struct sandbox_i2c_rtc_plat_data),
+	.ops		= &sandbox_i2c_rtc_emul_ops,
+};