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/misc/cros_ec_i2c.c

@@ -0,0 +1,152 @@
+/*
+ * Chromium OS cros_ec driver - I2C interface
+ *
+ * Copyright (c) 2012 The Chromium OS Authors.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * The Matrix Keyboard Protocol driver handles talking to the keyboard
+ * controller chip. Mostly this is for keyboard functions, but some other
+ * things have slipped in, so we provide generic services to talk to the
+ * KBC.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <i2c.h>
+#include <cros_ec.h>
+
+#ifdef DEBUG_TRACE
+#define debug_trace(fmt, b...)	debug(fmt, #b)
+#else
+#define debug_trace(fmt, b...)
+#endif
+
+static int cros_ec_i2c_command(struct udevice *udev, uint8_t cmd,
+			       int cmd_version, const uint8_t *dout,
+			       int dout_len, uint8_t **dinp, int din_len)
+{
+	struct cros_ec_dev *dev = dev_get_uclass_priv(udev);
+	/* version8, cmd8, arglen8, out8[dout_len], csum8 */
+	int out_bytes = dout_len + 4;
+	/* response8, arglen8, in8[din_len], checksum8 */
+	int in_bytes = din_len + 3;
+	uint8_t *ptr;
+	/* Receive input data, so that args will be dword aligned */
+	uint8_t *in_ptr;
+	int len, csum, ret;
+
+	/*
+	 * Sanity-check I/O sizes given transaction overhead in internal
+	 * buffers.
+	 */
+	if (out_bytes > sizeof(dev->dout)) {
+		debug("%s: Cannot send %d bytes\n", __func__, dout_len);
+		return -1;
+	}
+	if (in_bytes > sizeof(dev->din)) {
+		debug("%s: Cannot receive %d bytes\n", __func__, din_len);
+		return -1;
+	}
+	assert(dout_len >= 0);
+	assert(dinp);
+
+	/*
+	 * Copy command and data into output buffer so we can do a single I2C
+	 * burst transaction.
+	 */
+	ptr = dev->dout;
+
+	/*
+	 * in_ptr starts of pointing to a dword-aligned input data buffer.
+	 * We decrement it back by the number of header bytes we expect to
+	 * receive, so that the first parameter of the resulting input data
+	 * will be dword aligned.
+	 */
+	in_ptr = dev->din + sizeof(int64_t);
+
+	if (dev->protocol_version != 2) {
+		/* Something we don't support */
+		debug("%s: Protocol version %d unsupported\n",
+		      __func__, dev->protocol_version);
+		return -1;
+	}
+
+	*ptr++ = EC_CMD_VERSION0 + cmd_version;
+	*ptr++ = cmd;
+	*ptr++ = dout_len;
+	in_ptr -= 2;	/* Expect status, length bytes */
+
+	memcpy(ptr, dout, dout_len);
+	ptr += dout_len;
+
+	*ptr++ = (uint8_t)
+		cros_ec_calc_checksum(dev->dout, dout_len + 3);
+
+	/* Send output data */
+	cros_ec_dump_data("out", -1, dev->dout, out_bytes);
+	ret = dm_i2c_write(udev, 0, dev->dout, out_bytes);
+	if (ret) {
+		debug("%s: Cannot complete I2C write to %s\n", __func__,
+		      udev->name);
+		ret = -1;
+	}
+
+	if (!ret) {
+		ret = dm_i2c_read(udev, 0, in_ptr, in_bytes);
+		if (ret) {
+			debug("%s: Cannot complete I2C read from %s\n",
+			      __func__, udev->name);
+			ret = -1;
+		}
+	}
+
+	if (*in_ptr != EC_RES_SUCCESS) {
+		debug("%s: Received bad result code %d\n", __func__, *in_ptr);
+		return -(int)*in_ptr;
+	}
+
+	len = in_ptr[1];
+	if (len + 3 > sizeof(dev->din)) {
+		debug("%s: Received length %#02x too large\n",
+		      __func__, len);
+		return -1;
+	}
+	csum = cros_ec_calc_checksum(in_ptr, 2 + len);
+	if (csum != in_ptr[2 + len]) {
+		debug("%s: Invalid checksum rx %#02x, calced %#02x\n",
+		      __func__, in_ptr[2 + din_len], csum);
+		return -1;
+	}
+	din_len = min(din_len, len);
+	cros_ec_dump_data("in", -1, in_ptr, din_len + 3);
+
+	/* Return pointer to dword-aligned input data, if any */
+	*dinp = dev->din + sizeof(int64_t);
+
+	return din_len;
+}
+
+static int cros_ec_probe(struct udevice *dev)
+{
+	return cros_ec_register(dev);
+}
+
+static struct dm_cros_ec_ops cros_ec_ops = {
+	.command = cros_ec_i2c_command,
+};
+
+static const struct udevice_id cros_ec_ids[] = {
+	{ .compatible = "google,cros-ec-i2c" },
+	{ }
+};
+
+U_BOOT_DRIVER(cros_ec_i2c) = {
+	.name		= "cros_ec_i2c",
+	.id		= UCLASS_CROS_EC,
+	.of_match	= cros_ec_ids,
+	.probe		= cros_ec_probe,
+	.ops		= &cros_ec_ops,
+};