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/video/exynos/exynos_pwm_bl.c

@@ -0,0 +1,45 @@
+/*
+ * PWM BACKLIGHT driver for Board based on EXYNOS.
+ *
+ * Author: Donghwa Lee  <dh09.lee@samsung.com>
+ *
+ * Derived from linux/drivers/video/backlight/pwm_backlight.c
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <pwm.h>
+#include <linux/types.h>
+#include <asm/io.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/gpio.h>
+#include <asm/arch/pwm.h>
+#include <asm/arch/pwm_backlight.h>
+
+static struct pwm_backlight_data *pwm;
+
+static int exynos_pwm_backlight_update_status(void)
+{
+	int brightness = pwm->brightness;
+	int max = pwm->max_brightness;
+
+	if (brightness == 0) {
+		pwm_config(pwm->pwm_id, 0, pwm->period);
+		pwm_disable(pwm->pwm_id);
+	} else {
+		pwm_config(pwm->pwm_id,
+			brightness * pwm->period / max, pwm->period);
+		pwm_enable(pwm->pwm_id);
+	}
+	return 0;
+}
+
+int exynos_pwm_backlight_init(struct pwm_backlight_data *pd)
+{
+	pwm = pd;
+
+	exynos_pwm_backlight_update_status();
+
+	return 0;
+}