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>

doc/device-tree-bindings/pinctrl/nexell,s5pxx18-pinctrl.txt

@@ -0,0 +1,78 @@
+Binding for Nexell s5pxx18 pin cotroller
+========================================
+
+Nexell's ARM bases SoC's integrates a GPIO and Pin mux/config hardware
+controller. It controls the input/output settings on the available pads/pins
+and also provides ability to multiplex and configure the output of various
+on-chip controllers onto these pads.
+
+Please refer to pinctrl-bindings.txt in this directory for details of the
+common pinctrl bindings used by client devices, including the meaning of the
+phrase "pin configuration node".
+
+
+Required properties:
+  - compatible: "nexell,s5pxx18-pinctrl"
+  - reg: should be register base and length as documented in the datasheet
+  - interrupts: interrupt specifier for the controller over gpio and alive pins
+
+Example:
+pinctrl_0: pinctrl@c0010000 {
+	compatible = "nexell,s5pxx18-pinctrl";
+		reg = <0xc0010000 0xf000>;
+		u-boot,dm-pre-reloc;
+};
+
+Nexell's pin configuration nodes act as a container for an arbitrary number of
+subnodes. Each of these subnodes represents some desired configuration for a
+pin, a group, or a list of pins or groups. This configuration can include the
+mux function to select on those pin(s)/group(s), and various pin configuration
+parameters.
+
+  Child nodes must be set at least one of the following settings:
+  - pins = Select pins for using this function.
+  - pin-function = Select the function for use in a selected pin.
+  - pin-pull = Pull up/down configuration.
+  - pin-strength = Drive strength configuration.
+
+  Valid values for nexell,pins are:
+     "gpioX-N" : X in {A,B,C,D,E}, N in {0-31}
+  Valid values for nexell,pin-function are:
+     "N"       : N in {0-3}.
+                 This setting means that the value is different for each pin.
+                 Please refer to datasheet.
+  Valid values for nexell,pin-pull are:
+     "N"       : 0 - Down, 1 - Up, 2 - Off
+  Valid values for nexell,pin-strength are:
+     "N"       : 0,1,2,3
+
+
+Example:
+  - pin settings
+	mmc0_clk: mmc0-clk {
+		pins = "gpioa-29";
+		pin-function = <1>;
+		pin-pull = <2>;
+		pin-strength = <2>;
+	};
+
+	mmc0_cmd: mmc0-cmd {
+		pins = "gpioa-31";
+		pin-function = <1>;
+		pin-pull = <2>;
+		pin-strength = <1>;
+	};
+
+	mmc0_bus4: mmc0-bus-width4 {
+		pins = "gpiob-1, gpiob-3, gpiob-5, gpiob-7";
+		pin-function = <1>;
+		pin-pull = <2>;
+		pin-strength = <1>;
+	};
+
+  - used by client devices
+	mmc0:mmc@... {
+		pinctrl-names = "default";
+		pinctrl-0 = <&mmc0_clk>, <&mmc0_cmd>, <&mmc0_bus4>;
+		...
+	};

drivers/pinctrl/Kconfig

@@ -294,6 +294,7 @@ source "drivers/pinctrl/meson/Kconfig"
 source "drivers/pinctrl/mscc/Kconfig"
 source "drivers/pinctrl/mtmips/Kconfig"
 source "drivers/pinctrl/mvebu/Kconfig"
+source "drivers/pinctrl/nexell/Kconfig"
 source "drivers/pinctrl/nxp/Kconfig"
 source "drivers/pinctrl/renesas/Kconfig"
 source "drivers/pinctrl/rockchip/Kconfig"

drivers/pinctrl/Makefile

@@ -21,6 +21,7 @@ obj-$(CONFIG_PINCTRL_MESON)	+= meson/
 obj-$(CONFIG_PINCTRL_MTK)	+= mediatek/
 obj-$(CONFIG_PINCTRL_MSCC)	+= mscc/
 obj-$(CONFIG_ARCH_MVEBU)	+= mvebu/
+obj-$(CONFIG_ARCH_NEXELL)	+= nexell/
 obj-$(CONFIG_PINCTRL_SINGLE)	+= pinctrl-single.o
 obj-$(CONFIG_PINCTRL_STI)	+= pinctrl-sti.o
 obj-$(CONFIG_PINCTRL_STM32)	+= pinctrl_stm32.o

drivers/pinctrl/nexell/Kconfig

@@ -0,0 +1,18 @@
+if ARCH_NEXELL
+
+config PINCTRL_NEXELL
+	bool "Nexell pinctrl driver"
+	help
+	  Support of pin multiplexing and pin configuration for Nexell
+	  SoCs.
+
+config PINCTRL_NEXELL_S5PXX18
+	bool "Nexell s5pxx18 SoC pinctrl driver"
+	default y if ARCH_S5P4418 || ARCH_S5P6818
+	depends on ARCH_NEXELL && PINCTRL_FULL
+	select PINCTRL_NEXELL
+	help
+	  Support of pin multiplexing and pin configuration for S5P4418
+	  and S5P6818 SoC.
+
+endif

drivers/pinctrl/nexell/Makefile

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier:	GPL-2.0+
+#
+# (C) Copyright 2016 Nexell
+# Bongyu, KOO <freestyle@nexell.co.kr>
+
+obj-$(CONFIG_PINCTRL_NEXELL) += pinctrl-nexell.o
+obj-$(CONFIG_PINCTRL_NEXELL_S5PXX18) += pinctrl-s5pxx18.o

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;
+}

drivers/pinctrl/nexell/pinctrl-nexell.h

@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0+
+ *
+ * Pinctrl driver for Nexell SoCs
+ * (C) Copyright 2016 Nexell
+ * Bongyu, KOO <freestyle@nexell.co.kr>
+ *
+ */
+
+#ifndef __PINCTRL_NEXELL_H_
+#define __PINCTRL_NEXELL_H_
+
+/**
+ * struct nexell_pin_bank_data: represent a controller pin-bank data.
+ * @offset: starting offset of the pin-bank registers.
+ * @nr_pins: number of pins included in this bank.
+ * @name: name to be prefixed for each pin in this pin bank.
+ */
+struct nexell_pin_bank_data {
+	u32		offset;
+	u8		nr_pins;
+	const char	*name;
+	u8		type;
+};
+
+#define NEXELL_PIN_BANK(pins, reg, id)			\
+	{						\
+		.offset		= reg,			\
+		.nr_pins	= pins,			\
+		.name		= id			\
+	}
+
+/**
+ * struct nexell_pin_ctrl: represent a pin controller.
+ * @pin_banks: list of pin banks included in this controller.
+ * @nr_banks: number of pin banks.
+ */
+struct nexell_pin_ctrl {
+	const struct nexell_pin_bank_data *pin_banks;
+	u32 nr_banks;
+};
+
+/**
+ * struct nexell_pinctrl_priv: nexell pin controller driver private data
+ * @pin_ctrl: pin controller bank information.
+ * @base: base address of the pin controller instance.
+ */
+struct nexell_pinctrl_priv {
+	const struct nexell_pin_ctrl *pin_ctrl;
+	unsigned long base;
+};
+
+/**
+ * struct nexell_pinctrl_config_data: configuration for a peripheral.
+ * @offset: offset of the config registers in the controller.
+ * @mask: value of the register to be masked with.
+ * @value: new value to be programmed.
+ */
+struct nexell_pinctrl_config_data {
+	const unsigned int	offset;
+	const unsigned int	mask;
+	const unsigned int	value;
+};
+
+unsigned long pin_to_bank_base(struct udevice *dev, const char *pin_name,
+			       u32 *pin);
+int nexell_pinctrl_probe(struct udevice *dev);
+
+#endif /* __PINCTRL_NEXELL_H_ */

drivers/pinctrl/nexell/pinctrl-s5pxx18.c

@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Pinctrl driver for Nexell SoCs
+ * (C) Copyright 2016 Nexell
+ * Bongyu, KOO <freestyle@nexell.co.kr>
+ *
+ * (C) Copyright 2019 Stefan Bosch <stefan_b@posteo.net>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <dm/pinctrl.h>
+#include <dm/root.h>
+#include "pinctrl-nexell.h"
+#include "pinctrl-s5pxx18.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static void nx_gpio_set_bit(u32 *value, u32 bit, int enable)
+{
+	register u32 newvalue;
+
+	newvalue = *value;
+	newvalue &= ~(1ul << bit);
+	newvalue |= (u32)enable << bit;
+	writel(newvalue, value);
+}
+
+static void nx_gpio_set_bit2(u32 *value, u32 bit, u32 bit_value)
+{
+	register u32 newvalue = *value;
+
+	newvalue = (u32)(newvalue & ~(3ul << (bit * 2)));
+	newvalue = (u32)(newvalue | (bit_value << (bit * 2)));
+
+	writel(newvalue, value);
+}
+
+static int nx_gpio_open_module(void *base)
+{
+	writel(0xFFFFFFFF, base + GPIOX_SLEW_DISABLE_DEFAULT);
+	writel(0xFFFFFFFF, base + GPIOX_DRV1_DISABLE_DEFAULT);
+	writel(0xFFFFFFFF, base + GPIOX_DRV0_DISABLE_DEFAULT);
+	writel(0xFFFFFFFF, base + GPIOX_PULLSEL_DISABLE_DEFAULT);
+	writel(0xFFFFFFFF, base + GPIOX_PULLENB_DISABLE_DEFAULT);
+	return true;
+}
+
+static void nx_gpio_set_pad_function(void *base, u32 pin, u32 padfunc)
+{
+	u32 reg = (pin / 16) ? GPIOX_ALTFN1 : GPIOX_ALTFN0;
+
+	nx_gpio_set_bit2(base + reg, pin % 16, padfunc);
+}
+
+static void nx_gpio_set_drive_strength(void *base, u32 pin, u32 drv)
+{
+	nx_gpio_set_bit(base + GPIOX_DRV1, pin, (int)(((u32)drv >> 0) & 0x1));
+	nx_gpio_set_bit(base + GPIOX_DRV0, pin, (int)(((u32)drv >> 1) & 0x1));
+}
+
+static void nx_gpio_set_pull_mode(void *base, u32 pin, u32 mode)
+{
+	if (mode == nx_gpio_pull_off) {
+		nx_gpio_set_bit(base + GPIOX_PULLENB, pin, false);
+		nx_gpio_set_bit(base + GPIOX_PULLSEL, pin, false);
+	} else {
+		nx_gpio_set_bit(base + GPIOX_PULLSEL,
+				pin, (mode & 1 ? true : false));
+		nx_gpio_set_bit(base + GPIOX_PULLENB, pin, true);
+	}
+}
+
+static void nx_alive_set_pullup(void *base, u32 pin, bool enable)
+{
+	u32 PULLUP_MASK;
+
+	PULLUP_MASK = (1UL << pin);
+	if (enable)
+		writel(PULLUP_MASK, base + ALIVE_PADPULLUPSET);
+	else
+		writel(PULLUP_MASK, base + ALIVE_PADPULLUPRST);
+}
+
+static int s5pxx18_pinctrl_gpio_init(struct udevice *dev)
+{
+	struct nexell_pinctrl_priv *priv = dev_get_priv(dev);
+	const struct nexell_pin_ctrl *ctrl = priv->pin_ctrl;
+	unsigned long reg = priv->base;
+	int i;
+
+	for (i = 0; i < ctrl->nr_banks - 1; i++) /* except alive bank */
+		nx_gpio_open_module((void *)(reg + ctrl->pin_banks[i].offset));
+
+	return 0;
+}
+
+static int s5pxx18_pinctrl_alive_init(struct udevice *dev)
+{
+	struct nexell_pinctrl_priv *priv = dev_get_priv(dev);
+	const struct nexell_pin_ctrl *ctrl = priv->pin_ctrl;
+	unsigned long reg = priv->base;
+
+	reg += ctrl->pin_banks[ctrl->nr_banks - 1].offset;
+
+	writel(1, reg + ALIVE_PWRGATE);
+	return 0;
+}
+
+int s5pxx18_pinctrl_init(struct udevice *dev)
+{
+	s5pxx18_pinctrl_gpio_init(dev);
+	s5pxx18_pinctrl_alive_init(dev);
+
+	return 0;
+}
+
+static int is_pin_alive(const char *name)
+{
+	return !strncmp(name, "alive", 5);
+}
+
+/**
+ * s5pxx18_pinctrl_set_state: configure a pin state.
+ * dev: the pinctrl device to be configured.
+ * config: the state to be configured.
+ */
+static int s5pxx18_pinctrl_set_state(struct udevice *dev,
+				     struct udevice *config)
+{
+	unsigned int count, idx, pin;
+	unsigned int pinfunc, pinpud, pindrv;
+	unsigned long reg;
+	const char *name;
+	int ret;
+
+	/*
+	 * refer to the following document for the pinctrl bindings
+	 * doc/device-tree-bindings/pinctrl/nexell,s5pxx18-pinctrl.txt
+	 */
+	count = dev_read_string_count(config, "pins");
+
+	if (count <= 0)
+		return -EINVAL;
+
+	pinfunc = dev_read_s32_default(config, "pin-function", -1);
+	pinpud = dev_read_s32_default(config, "pin-pull", -1);
+	pindrv = dev_read_s32_default(config, "pin-strength", -1);
+
+	for (idx = 0; idx < count; idx++) {
+		ret = dev_read_string_index(config, "pins", idx, &name);
+		if (ret)
+			return ret;
+		if (!name)
+			continue;
+		reg = pin_to_bank_base(dev, name, &pin);
+
+		if (is_pin_alive(name)) {
+			/* pin pull up/down */
+			if (pinpud != -1)
+				nx_alive_set_pullup((void *)reg, pin,
+						    pinpud & 1);
+			continue;
+		}
+
+		/* pin function */
+		if (pinfunc != -1)
+			nx_gpio_set_pad_function((void *)reg, pin, pinfunc);
+
+		/* pin pull up/down/off */
+		if (pinpud != -1)
+			nx_gpio_set_pull_mode((void *)reg, pin, pinpud);
+
+		/* pin drive strength */
+		if (pindrv != -1)
+			nx_gpio_set_drive_strength((void *)reg, pin, pindrv);
+	}
+
+	return 0;
+}
+
+static struct pinctrl_ops s5pxx18_pinctrl_ops = {
+	.set_state	= s5pxx18_pinctrl_set_state,
+};
+
+/* pin banks of s5pxx18 pin-controller */
+static const struct nexell_pin_bank_data s5pxx18_pin_banks[] = {
+	NEXELL_PIN_BANK(32, 0xA000, "gpioa"),
+	NEXELL_PIN_BANK(32, 0xB000, "gpiob"),
+	NEXELL_PIN_BANK(32, 0xC000, "gpioc"),
+	NEXELL_PIN_BANK(32, 0xD000, "gpiod"),
+	NEXELL_PIN_BANK(32, 0xE000, "gpioe"),
+	NEXELL_PIN_BANK(6, 0x0800, "alive"),
+};
+
+const struct nexell_pin_ctrl s5pxx18_pin_ctrl[] = {
+	{
+		/* pin-controller data */
+		.pin_banks	= s5pxx18_pin_banks,
+		.nr_banks	= ARRAY_SIZE(s5pxx18_pin_banks),
+	},
+};
+
+static const struct udevice_id s5pxx18_pinctrl_ids[] = {
+	{ .compatible = "nexell,s5pxx18-pinctrl",
+		.data = (ulong)s5pxx18_pin_ctrl },
+	{ }
+};
+
+U_BOOT_DRIVER(pinctrl_s5pxx18) = {
+	.name		= "pinctrl_s5pxx18",
+	.id		= UCLASS_PINCTRL,
+	.of_match	= s5pxx18_pinctrl_ids,
+	.priv_auto_alloc_size = sizeof(struct nexell_pinctrl_priv),
+	.ops		= &s5pxx18_pinctrl_ops,
+	.probe		= nexell_pinctrl_probe,
+	.flags		= DM_FLAG_PRE_RELOC
+};

drivers/pinctrl/nexell/pinctrl-s5pxx18.h

@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0+
+ *
+ * Pinctrl driver for Nexell SoCs
+ * (C) Copyright 2016 Nexell
+ * Bongyu, KOO <freestyle@nexell.co.kr>
+ */
+
+#ifndef __PINCTRL_S5PXX18_H_
+#define __PINCTRL_S5PXX18_H_
+
+#include <linux/types.h>
+#include <asm/io.h>
+
+#define GPIOX_ALTFN0	0x20
+#define GPIOX_ALTFN1	0x24
+#define GPIOX_DRV1	0x48
+#define GPIOX_DRV0	0x50
+#define GPIOX_PULLSEL	0x58
+#define GPIOX_PULLENB	0x60
+
+#define GPIOX_SLEW_DISABLE_DEFAULT	0x44
+#define GPIOX_DRV1_DISABLE_DEFAULT	0x4C
+#define GPIOX_DRV0_DISABLE_DEFAULT	0x54
+#define GPIOX_PULLSEL_DISABLE_DEFAULT	0x5C
+#define GPIOX_PULLENB_DISABLE_DEFAULT	0x64
+
+#define ALIVE_PWRGATE			0x0
+#define ALIVE_PADPULLUPRST		0x80
+#define ALIVE_PADPULLUPSET		0x84
+#define ALIVE_PADPULLUPREAD		0x88
+
+enum {
+	nx_gpio_padfunc_0 = 0ul,
+	nx_gpio_padfunc_1 = 1ul,
+	nx_gpio_padfunc_2 = 2ul,
+	nx_gpio_padfunc_3 = 3ul
+};
+
+enum {
+	nx_gpio_drvstrength_0 = 0ul,
+	nx_gpio_drvstrength_1 = 1ul,
+	nx_gpio_drvstrength_2 = 2ul,
+	nx_gpio_drvstrength_3 = 3ul
+};
+
+enum {
+	nx_gpio_pull_down = 0ul,
+	nx_gpio_pull_up = 1ul,
+	nx_gpio_pull_off = 2ul
+};
+
+int s5pxx18_pinctrl_init(struct udevice *dev);
+#endif /* __PINCTRL_S5PXX18_H_ */