arm: add mach-nexell (all files except header files)

Changes in relation to FriendlyARM's U-Boot nanopi2-v2016.01:
- SPL not supported yet --> no spl-directory in arch/arm/mach-nexell.
  Appropriate line in Makefile removed.
- clock.c: 'section(".data")' added to declaration of clk_periphs[] and
  core_hz.
- Kconfig: Changes to have a structure like in mach-bcm283x/Kconfig,
  e.g. "config ..." entries moved from other Kconfig.
- timer.c: 'section(".data")' added to declaration of timestamp and
  lastdec.
- arch/arm/mach-nexell/serial.c removed because this is for the UARTs
  of the S5P6818 SoC which is not supported yet. S5P4418 UARTs are
  different, here the (existing) PL011-code is used.
- '#ifdef CONFIG...' changed to 'if (IS_ENABLED(CONFIG...))' where
  possible (and similar).

Signed-off-by: Stefan Bosch <stefan_b@posteo.net>
diff --git a/arch/arm/mach-nexell/tieoff.c b/arch/arm/mach-nexell/tieoff.c
new file mode 100644
index 0000000..5a4744c
--- /dev/null
+++ b/arch/arm/mach-nexell/tieoff.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2016 Nexell
+ * Youngbok, Park <park@nexell.co.kr>
+ */
+
+#include <common.h>
+#include <asm/arch/nexell.h>
+#include <asm/arch/clk.h>
+#include <asm/arch/reset.h>
+#include <asm/arch/nx_gpio.h>
+#include <asm/arch/tieoff.h>
+#include <asm/arch/sec_reg.h>
+
+#define	NX_PIN_FN_SIZE	4
+#define TIEOFF_REG_NUM 33
+
+struct	nx_tieoff_registerset {
+	u32	tieoffreg[TIEOFF_REG_NUM];
+};
+
+static struct nx_tieoff_registerset *nx_tieoff = (void *)PHY_BASEADDR_TIEOFF;
+
+static int tieoff_readl(void __iomem *reg)
+{
+	if (IS_ENABLED(CONFIG_ARCH_S5P4418))
+		return read_sec_reg_by_id(reg, NEXELL_TOFF_SEC_ID);
+	else
+		return readl(reg);
+}
+
+static int  tieoff_writetl(void __iomem *reg, int val)
+{
+	if (IS_ENABLED(CONFIG_ARCH_S5P4418))
+		return write_sec_reg_by_id(reg, val, NEXELL_TOFF_SEC_ID);
+	else
+		return writel(val, reg);
+}
+
+void nx_tieoff_set(u32 tieoff_index, u32 tieoff_value)
+{
+	u32 regindex, mask;
+	u32 lsb, msb;
+	u32 regval;
+
+	u32 position;
+	u32 bitwidth;
+
+	position = tieoff_index & 0xffff;
+	bitwidth = (tieoff_index >> 16) & 0xffff;
+
+	regindex	= position >> 5;
+
+	lsb = position & 0x1F;
+	msb = lsb + bitwidth;
+
+	if (msb > 32) {
+		msb &= 0x1F;
+		mask   = ~(0xffffffff << lsb);
+		regval = tieoff_readl(&nx_tieoff->tieoffreg[regindex]) & mask;
+		regval |= ((tieoff_value & ((1UL << bitwidth) - 1)) << lsb);
+		tieoff_writetl(&nx_tieoff->tieoffreg[regindex], regval);
+
+		mask   = (0xffffffff << msb);
+		regval = tieoff_readl(&nx_tieoff->tieoffreg[regindex]) & mask;
+		regval |= ((tieoff_value & ((1UL << bitwidth) - 1)) >> msb);
+		tieoff_writetl(&nx_tieoff->tieoffreg[regindex + 1], regval);
+	} else	{
+		mask	= (0xffffffff << msb) | (~(0xffffffff << lsb));
+		regval = tieoff_readl(&nx_tieoff->tieoffreg[regindex]) & mask;
+		regval	|= ((tieoff_value & ((1UL << bitwidth) - 1)) << lsb);
+		tieoff_writetl(&nx_tieoff->tieoffreg[regindex], regval);
+	}
+}
+
+u32 nx_tieoff_get(u32 tieoff_index)
+{
+	u32 regindex, mask;
+	u32 lsb, msb;
+	u32 regval;
+
+	u32 position;
+	u32 bitwidth;
+
+	position = tieoff_index & 0xffff;
+	bitwidth = (tieoff_index >> 16) & 0xffff;
+
+	regindex = position / 32;
+	lsb = position % 32;
+	msb = lsb + bitwidth;
+
+	if (msb > 32) {
+		msb &= 0x1F;
+		mask   = 0xffffffff << lsb;
+		regval = tieoff_readl(&nx_tieoff->tieoffreg[regindex]) & mask;
+		regval >>= lsb;
+
+		mask   = ~(0xffffffff << msb);
+		regval |= ((tieoff_readl(&nx_tieoff->tieoffreg[regindex + 1])
+					& mask) << (32 - lsb));
+	} else	{
+		mask   = ~(0xffffffff << msb) & (0xffffffff << lsb);
+		regval = tieoff_readl(&nx_tieoff->tieoffreg[regindex]) & mask;
+		regval >>= lsb;
+	}
+	return regval;
+}