pinctrl: add nexell driver

Changes in relation to FriendlyARM's U-Boot nanopi2-v2016.01:
- livetree API (dev_read_...) is used instead of fdt one (fdt...).
- doc/device-tree-bindings/pinctrl/nexell,s5pxx18-pinctrl.txt added.

Signed-off-by: Stefan Bosch <stefan_b@posteo.net>
diff --git a/drivers/pinctrl/nexell/pinctrl-nexell.c b/drivers/pinctrl/nexell/pinctrl-nexell.c
new file mode 100644
index 0000000..4518c05
--- /dev/null
+++ b/drivers/pinctrl/nexell/pinctrl-nexell.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Pinctrl driver for Nexell SoCs
+ * (C) Copyright 2016 Nexell
+ * Bongyu, KOO <freestyle@nexell.co.kr>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <asm/io.h>
+#include "pinctrl-nexell.h"
+#include "pinctrl-s5pxx18.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* given a pin-name, return the address of pin config registers */
+unsigned long pin_to_bank_base(struct udevice *dev, const char *pin_name,
+			       u32 *pin)
+{
+	struct nexell_pinctrl_priv *priv = dev_get_priv(dev);
+	const struct nexell_pin_ctrl *pin_ctrl = priv->pin_ctrl;
+	const struct nexell_pin_bank_data *bank_data = pin_ctrl->pin_banks;
+	u32 nr_banks = pin_ctrl->nr_banks, idx = 0;
+	char bank[10];
+
+	/*
+	 * The format of the pin name is <bank name>-<pin_number>.
+	 * Example: gpioa-4 (gpioa is the bank name and 4 is the pin number)
+	 */
+	while (pin_name[idx] != '-') {
+		bank[idx] = pin_name[idx];
+		idx++;
+	}
+	bank[idx] = '\0';
+	*pin = (u32)simple_strtoul(&pin_name[++idx], NULL, 10);
+
+	/* lookup the pin bank data using the pin bank name */
+	for (idx = 0; idx < nr_banks; idx++)
+		if (!strcmp(bank, bank_data[idx].name))
+			break;
+
+	return priv->base + bank_data[idx].offset;
+}
+
+int nexell_pinctrl_probe(struct udevice *dev)
+{
+	struct nexell_pinctrl_priv *priv;
+	fdt_addr_t base;
+
+	priv = dev_get_priv(dev);
+	if (!priv)
+		return -EINVAL;
+
+	base = devfdt_get_addr(dev);
+	if (base == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	priv->base = base;
+
+	priv->pin_ctrl = (struct nexell_pin_ctrl *)dev_get_driver_data(dev);
+
+	s5pxx18_pinctrl_init(dev);
+
+	return 0;
+}