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/hwmon/lm63.c

@@ -0,0 +1,160 @@
+/*
+ * (C) Copyright 2007-2008
+ * Dirk Eibach,  Guntermann & Drunck GmbH, eibach@gdsys.de
+ * based on lm75.c by Bill Hunter
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * National LM63/LM64 Temperature Sensor
+ * Main difference: LM 64 has -16 Kelvin temperature offset
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <dtt.h>
+
+#define DTT_I2C_LM63_ADDR	0x4C	/* National LM63 device */
+
+#define DTT_READ_TEMP_RMT_MSB	0x01
+#define DTT_CONFIG		0x03
+#define DTT_READ_TEMP_RMT_LSB	0x10
+#define DTT_TACHLIM_LSB		0x48
+#define DTT_TACHLIM_MSB		0x49
+#define DTT_FAN_CONFIG		0x4A
+#define DTT_PWM_FREQ		0x4D
+#define DTT_PWM_LOOKUP_BASE	0x50
+
+struct pwm_lookup_entry {
+	u8 temp;
+	u8 pwm;
+};
+
+/*
+ * Device code
+ */
+
+int dtt_read(int sensor, int reg)
+{
+	int dlen;
+	uchar data[2];
+
+	/*
+	 * Calculate sensor address and register.
+	 */
+	if (!sensor)
+		sensor = DTT_I2C_LM63_ADDR;	/* legacy config */
+
+	dlen = 1;
+
+	/*
+	 * Now try to read the register.
+	 */
+	if (i2c_read(sensor, reg, 1, data, dlen) != 0)
+		return -1;
+
+	return (int)data[0];
+}				/* dtt_read() */
+
+int dtt_write(int sensor, int reg, int val)
+{
+	int dlen;
+	uchar data[2];
+
+	/*
+	 * Calculate sensor address and register.
+	 */
+	if (!sensor)
+		sensor = DTT_I2C_LM63_ADDR;	/* legacy config */
+
+	dlen = 1;
+	data[0] = (char)(val & 0xff);
+
+	/*
+	 * Write value to register.
+	 */
+	if (i2c_write(sensor, reg, 1, data, dlen) != 0)
+		return 1;
+
+	return 0;
+}				/* dtt_write() */
+
+static int is_lm64(int sensor)
+{
+	return sensor && (sensor != DTT_I2C_LM63_ADDR);
+}
+
+int dtt_init_one(int sensor)
+{
+	int i;
+	int val;
+
+	struct pwm_lookup_entry pwm_lookup[] = CONFIG_DTT_PWM_LOOKUPTABLE;
+
+	/*
+	 * Set PWM Frequency to 2.5% resolution
+	 */
+	val = 20;
+	if (dtt_write(sensor, DTT_PWM_FREQ, val) != 0)
+		return 1;
+
+	/*
+	 * Set Tachometer Limit
+	 */
+	val = CONFIG_DTT_TACH_LIMIT;
+	if (dtt_write(sensor, DTT_TACHLIM_LSB, val & 0xff) != 0)
+		return 1;
+	if (dtt_write(sensor, DTT_TACHLIM_MSB, (val >> 8) & 0xff) != 0)
+		return 1;
+
+	/*
+	 * Make sure PWM Lookup-Table is writeable
+	 */
+	if (dtt_write(sensor, DTT_FAN_CONFIG, 0x20) != 0)
+		return 1;
+
+	/*
+	 * Setup PWM Lookup-Table
+	 */
+	for (i = 0; i < ARRAY_SIZE(pwm_lookup); i++) {
+		int address = DTT_PWM_LOOKUP_BASE + 2 * i;
+		val = pwm_lookup[i].temp;
+		if (is_lm64(sensor))
+			val -= 16;
+		if (dtt_write(sensor, address, val) != 0)
+			return 1;
+		val = dtt_read(sensor, address);
+		val = pwm_lookup[i].pwm;
+		if (dtt_write(sensor, address + 1, val) != 0)
+			return 1;
+	}
+
+	/*
+	 * Enable PWM Lookup-Table, PWM Clock 360 kHz, Tachometer Mode 2
+	 */
+	val = 0x02;
+	if (dtt_write(sensor, DTT_FAN_CONFIG, val) != 0)
+		return 1;
+
+	/*
+	 * Enable Tach input
+	 */
+	val = dtt_read(sensor, DTT_CONFIG) | 0x04;
+	if (dtt_write(sensor, DTT_CONFIG, val) != 0)
+		return 1;
+
+	return 0;
+}
+
+int dtt_get_temp(int sensor)
+{
+	s16 temp = (dtt_read(sensor, DTT_READ_TEMP_RMT_MSB) << 8)
+	    | (dtt_read(sensor, DTT_READ_TEMP_RMT_LSB));
+
+	if (is_lm64(sensor))
+		temp += 16 << 8;
+
+	/* Ignore LSB for now, U-Boot only prints natural numbers */
+	return temp >> 8;
+}