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/spi/soft_spi_legacy.c

@@ -0,0 +1,176 @@
+/*
+ * (C) Copyright 2002
+ * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
+ *
+ * Influenced by code from:
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <spi.h>
+
+#include <malloc.h>
+
+/*-----------------------------------------------------------------------
+ * Definitions
+ */
+
+#ifdef DEBUG_SPI
+#define PRINTD(fmt,args...)	printf (fmt ,##args)
+#else
+#define PRINTD(fmt,args...)
+#endif
+
+struct soft_spi_slave {
+	struct spi_slave slave;
+	unsigned int mode;
+};
+
+static inline struct soft_spi_slave *to_soft_spi(struct spi_slave *slave)
+{
+	return container_of(slave, struct soft_spi_slave, slave);
+}
+
+/*=====================================================================*/
+/*                         Public Functions                            */
+/*=====================================================================*/
+
+/*-----------------------------------------------------------------------
+ * Initialization
+ */
+void spi_init (void)
+{
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+		unsigned int max_hz, unsigned int mode)
+{
+	struct soft_spi_slave *ss;
+
+	if (!spi_cs_is_valid(bus, cs))
+		return NULL;
+
+	ss = spi_alloc_slave(struct soft_spi_slave, bus, cs);
+	if (!ss)
+		return NULL;
+
+	ss->mode = mode;
+
+	/* TODO: Use max_hz to limit the SCK rate */
+
+	return &ss->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	struct soft_spi_slave *ss = to_soft_spi(slave);
+
+	free(ss);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+#ifdef CONFIG_SYS_IMMR
+	volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
+#endif
+	struct soft_spi_slave *ss = to_soft_spi(slave);
+
+	/*
+	 * Make sure the SPI clock is in idle state as defined for
+	 * this slave.
+	 */
+	if (ss->mode & SPI_CPOL)
+		SPI_SCL(1);
+	else
+		SPI_SCL(0);
+
+	return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	/* Nothing to do */
+}
+
+/*-----------------------------------------------------------------------
+ * SPI transfer
+ *
+ * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
+ * "bitlen" bits in the SPI MISO port.  That's just the way SPI works.
+ *
+ * The source of the outgoing bits is the "dout" parameter and the
+ * destination of the input bits is the "din" parameter.  Note that "dout"
+ * and "din" can point to the same memory location, in which case the
+ * input data overwrites the output data (since both are buffered by
+ * temporary variables, this is OK).
+ */
+int  spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+		const void *dout, void *din, unsigned long flags)
+{
+#ifdef CONFIG_SYS_IMMR
+	volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
+#endif
+	struct soft_spi_slave *ss = to_soft_spi(slave);
+	uchar		tmpdin  = 0;
+	uchar		tmpdout = 0;
+	const u8	*txd = dout;
+	u8		*rxd = din;
+	int		cpol = ss->mode & SPI_CPOL;
+	int		cpha = ss->mode & SPI_CPHA;
+	unsigned int	j;
+
+	PRINTD("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
+		slave->bus, slave->cs, *(uint *)txd, *(uint *)rxd, bitlen);
+
+	if (flags & SPI_XFER_BEGIN)
+		spi_cs_activate(slave);
+
+	for(j = 0; j < bitlen; j++) {
+		/*
+		 * Check if it is time to work on a new byte.
+		 */
+		if ((j % 8) == 0) {
+			if (txd)
+				tmpdout = *txd++;
+			else
+				tmpdout = 0;
+			if(j != 0) {
+				if (rxd)
+					*rxd++ = tmpdin;
+			}
+			tmpdin  = 0;
+		}
+
+		if (!cpha)
+			SPI_SCL(!cpol);
+		SPI_SDA(tmpdout & 0x80);
+		SPI_DELAY;
+		if (cpha)
+			SPI_SCL(!cpol);
+		else
+			SPI_SCL(cpol);
+		tmpdin	<<= 1;
+		tmpdin	|= SPI_READ;
+		tmpdout	<<= 1;
+		SPI_DELAY;
+		if (cpha)
+			SPI_SCL(cpol);
+	}
+	/*
+	 * If the number of bits isn't a multiple of 8, shift the last
+	 * bits over to left-justify them.  Then store the last byte
+	 * read in.
+	 */
+	if (rxd) {
+		if ((bitlen % 8) != 0)
+			tmpdin <<= 8 - (bitlen % 8);
+		*rxd++ = tmpdin;
+	}
+
+	if (flags & SPI_XFER_END)
+		spi_cs_deactivate(slave);
+
+	return(0);
+}