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/arch/arm/mach-sunxi/clock_sun9i.c

@@ -0,0 +1,68 @@
+/*
+ * sun9i specific clock code
+ *
+ * (C) Copyright 2015 Hans de Goede <hdegoede@redhat.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/prcm.h>
+#include <asm/arch/sys_proto.h>
+
+void clock_init_uart(void)
+{
+	struct sunxi_ccm_reg *const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+
+	/* open the clock for uart */
+	setbits_le32(&ccm->apb1_gate,
+		     CLK_GATE_OPEN << (APB1_GATE_UART_SHIFT +
+				       CONFIG_CONS_INDEX - 1));
+	/* deassert uart reset */
+	setbits_le32(&ccm->apb1_reset_cfg,
+		     1 << (APB1_RESET_UART_SHIFT +
+			   CONFIG_CONS_INDEX - 1));
+
+	/* Dup with clock_init_safe(), drop once sun9i SPL support lands */
+	writel(PLL4_CFG_DEFAULT, &ccm->pll4_periph0_cfg);
+}
+
+int clock_twi_onoff(int port, int state)
+{
+	struct sunxi_ccm_reg *const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+
+	if (port > 4)
+		return -1;
+
+	/* set the apb reset and clock gate for twi */
+	if (state) {
+		setbits_le32(&ccm->apb1_gate,
+			     CLK_GATE_OPEN << (APB1_GATE_TWI_SHIFT + port));
+		setbits_le32(&ccm->apb1_reset_cfg,
+			     1 << (APB1_RESET_TWI_SHIFT + port));
+	} else {
+		clrbits_le32(&ccm->apb1_reset_cfg,
+			     1 << (APB1_RESET_TWI_SHIFT + port));
+		clrbits_le32(&ccm->apb1_gate,
+			     CLK_GATE_OPEN << (APB1_GATE_TWI_SHIFT + port));
+	}
+
+	return 0;
+}
+
+unsigned int clock_get_pll4_periph0(void)
+{
+	struct sunxi_ccm_reg *const ccm =
+		(struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+	uint32_t rval = readl(&ccm->pll4_periph0_cfg);
+	int n = ((rval & CCM_PLL4_CTRL_N_MASK) >> CCM_PLL4_CTRL_N_SHIFT);
+	int p = ((rval & CCM_PLL4_CTRL_P_MASK) >> CCM_PLL4_CTRL_P_SHIFT);
+	int m = ((rval & CCM_PLL4_CTRL_M_MASK) >> CCM_PLL4_CTRL_M_SHIFT) + 1;
+	const int k = 1;
+
+	return ((24000000 * n * k) >> p) / m;
+}