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/include/spmi/spmi.h

@@ -0,0 +1,46 @@
+#ifndef _SPMI_SPMI_H
+#define _SPMI_SPMI_H
+
+/**
+ * struct dm_spmi_ops - SPMI device I/O interface
+ *
+ * Should be implemented by UCLASS_SPMI device drivers. The standard
+ * device operations provides the I/O interface for it's childs.
+ *
+ * @read:      read register 'reg' of slave 'usid' and peripheral 'pid'
+ * @write:     write register 'reg' of slave 'usid' and peripheral 'pid'
+ *
+ * Each register is 8-bit, both read and write can return negative values
+ * on error.
+ */
+struct dm_spmi_ops {
+	int (*read)(struct udevice *dev, int usid, int pid, int reg);
+	int (*write)(struct udevice *dev, int usid, int pid, int reg,
+		     uint8_t value);
+};
+
+/**
+ * spmi_reg_read() - read a register from specific slave/peripheral
+ *
+ * @dev:	SPMI bus to read
+ * @usid	SlaveID
+ * @pid		Peripheral ID
+ * @reg:	Register to read
+ * @return value read on success or negative value of errno.
+ */
+int spmi_reg_read(struct udevice *dev, int usid, int pid, int reg);
+
+/**
+ * spmi_reg_write() - write a register of specific slave/peripheral
+ *
+ * @dev:	SPMI bus to write
+ * @usid	SlaveID
+ * @pid		Peripheral ID
+ * @reg:	Register to write
+ * @value:	Value to write
+ * @return 0 on success or negative value of errno.
+ */
+int spmi_reg_write(struct udevice *dev, int usid, int pid, int reg,
+		   uint8_t value);
+
+#endif