gpio-nct5104d: Add nct5104d driver package

This adds support for the SuperIO chip nct5104d found on the PC Engines
APU boards, which allows for a handful of additional ports, such as 2x
additional UART pinouts, enabling an external watchdog (no driver for
this functionality yet), and 16 GPIO pins. More info can be found at
https://pcengines.ch/ht_gpio.htm

Thanks to @feckert for helping package this.

Cc: Florian Eckert <Eckert.Florian@googlemail.com>

Signed-off-by: Chris Blake <chrisrblake93@gmail.com>

4 files changed, 519 insertions, 0 deletions

diff --git a/package/kernel/gpio-nct5104d/Makefile b/package/kernel/gpio-nct5104d/Makefile
new file mode 100644
index 0000000000..b43291e5a4
--- /dev/null
+++ b/package/kernel/gpio-nct5104d/Makefile
@@ -0,0 +1,52 @@
+#
+# Copyright (C) 2017 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+PKG_NAME:=gpio-nct5104d
+PKG_RELEASE:=1
+
+PKG_MAINTAINER:=Florian Eckert <Eckert.Florian@googlemail.com>
+PKG_LICENSE:=GPL-2.0
+
+include $(INCLUDE_DIR)/package.mk
+
+define KernelPackage/gpio-nct5104d
+  SUBMENU:=Other modules
+  TITLE:= GPIO nct5104d support
+  DEPENDS:= @GPIO_SUPPORT @TARGET_x86
+  FILES:=$(PKG_BUILD_DIR)/gpio-nct5104d.ko
+  AUTOLOAD:=$(call AutoLoad,30,gpio-nct5104d,1)
+  KCONFIG:=
+endef
+
+define KernelPackage/gpio-nct5104d/description
+  Support for GPIO functionality of NCT5104D super I/O chip.
+endef
+
+EXTRA_KCONFIG:= \
+	CONFIG_GPIO_NCT5104D=m
+
+EXTRA_CFLAGS:= \
+	$(patsubst CONFIG_%, -DCONFIG_%=1, $(patsubst %=m,%,$(filter %=m,$(EXTRA_KCONFIG)))) \
+	$(patsubst CONFIG_%, -DCONFIG_%=1, $(patsubst %=y,%,$(filter %=y,$(EXTRA_KCONFIG)))) \
+
+MAKE_OPTS:= \
+	ARCH="$(LINUX_KARCH)" \
+	CROSS_COMPILE="$(TARGET_CROSS)" \
+	SUBDIRS="$(PKG_BUILD_DIR)" \
+	EXTRA_CFLAGS="$(EXTRA_CFLAGS)" \
+	$(EXTRA_KCONFIG)
+
+define Build/Compile
+	 $(MAKE) -C "$(LINUX_DIR)" \
+		$(MAKE_OPTS) \
+		modules
+endef
+
+$(eval $(call KernelPackage,gpio-nct5104d))
diff --git a/package/kernel/gpio-nct5104d/src/Kconfig b/package/kernel/gpio-nct5104d/src/Kconfig
new file mode 100644
index 0000000000..cf658e29cf
--- /dev/null
+++ b/package/kernel/gpio-nct5104d/src/Kconfig
@@ -0,0 +1,5 @@
+config GPIO_NCT5104D
+        tristate "NCT5104D GPIO support"
+        depends on GENERIC_GPIO
+        help
+          Say yes here to support GPIO functionality of NCT5104D super I/O chip
diff --git a/package/kernel/gpio-nct5104d/src/Makefile b/package/kernel/gpio-nct5104d/src/Makefile
new file mode 100644
index 0000000000..6f0375a343
--- /dev/null
+++ b/package/kernel/gpio-nct5104d/src/Makefile
@@ -0,0 +1 @@
+obj-${CONFIG_GPIO_NCT5104D}    += gpio-nct5104d.o
diff --git a/package/kernel/gpio-nct5104d/src/gpio-nct5104d.c b/package/kernel/gpio-nct5104d/src/gpio-nct5104d.c
new file mode 100644
index 0000000000..a37a1d056d
--- /dev/null
+++ b/package/kernel/gpio-nct5104d/src/gpio-nct5104d.c
@@ -0,0 +1,461 @@
+/*
+ * GPIO driver for NCT5104D
+ *
+ * Author: Tasanakorn Phaipool <tasanakorn@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/version.h>
+#include <linux/dmi.h>
+#include <linux/string.h>
+
+#define DRVNAME "gpio-nct5104d"
+
+/*
+ * Super-I/O registers
+ */
+#define SIO_LDSEL		0x07	/* Logical device select */
+#define SIO_CHIPID		0x20	/* Chaip ID (2 bytes) */
+#define SIO_GPIO_ENABLE	0x30	/* GPIO enable */
+#define SIO_GPIO1_MODE		0xE0	/* GPIO1 Mode OpenDrain/Push-Pull */
+#define SIO_GPIO2_MODE		0xE1	/* GPIO2 Mode OpenDrain/Push-Pull */
+
+#define SIO_LD_GPIO		0x07	/* GPIO logical device */
+#define SIO_LD_GPIO_MODE	0x0F	/* GPIO mode control device */
+#define SIO_UNLOCK_KEY		0x87	/* Key to enable Super-I/O */
+#define SIO_LOCK_KEY		0xAA	/* Key to disable Super-I/O */
+
+#define SIO_NCT5104D_ID					0x1061	/* Chip ID */
+#define SIO_PCENGINES_APU_NCT5104D_ID	0xc452	/* Chip ID */
+
+enum chips { nct5104d };
+
+static const char * const nct5104d_names[] = {
+	"nct5104d"
+};
+
+struct nct5104d_sio {
+	int addr;
+	enum chips type;
+};
+
+struct nct5104d_gpio_bank {
+	struct gpio_chip chip;
+	unsigned int regbase;
+	struct nct5104d_gpio_data *data;
+};
+
+struct nct5104d_gpio_data {
+	struct nct5104d_sio *sio;
+	int nr_bank;
+	struct nct5104d_gpio_bank *bank;
+};
+
+/*
+ * Super-I/O functions.
+ */
+
+static inline int superio_inb(int base, int reg)
+{
+	outb(reg, base);
+	return inb(base + 1);
+}
+
+static int superio_inw(int base, int reg)
+{
+	int val;
+
+	outb(reg++, base);
+	val = inb(base + 1) << 8;
+	outb(reg, base);
+	val |= inb(base + 1);
+
+	return val;
+}
+
+static inline void superio_outb(int base, int reg, int val)
+{
+	outb(reg, base);
+	outb(val, base + 1);
+}
+
+static inline int superio_enter(int base)
+{
+	/* Don't step on other drivers' I/O space by accident. */
+	if (!request_muxed_region(base, 2, DRVNAME)) {
+		pr_err(DRVNAME "I/O address 0x%04x already in use\n", base);
+		return -EBUSY;
+	}
+
+	/* According to the datasheet the key must be send twice. */
+	outb(SIO_UNLOCK_KEY, base);
+	outb(SIO_UNLOCK_KEY, base);
+
+	return 0;
+}
+
+static inline void superio_select(int base, int ld)
+{
+	outb(SIO_LDSEL, base);
+	outb(ld, base + 1);
+}
+
+static inline void superio_exit(int base)
+{
+	outb(SIO_LOCK_KEY, base);
+	release_region(base, 2);
+}
+
+/*
+ * GPIO chip.
+ */
+
+static int nct5104d_gpio_direction_in(struct gpio_chip *chip, unsigned offset);
+static int nct5104d_gpio_get(struct gpio_chip *chip, unsigned offset);
+static int nct5104d_gpio_direction_out(struct gpio_chip *chip,
+				     unsigned offset, int value);
+static void nct5104d_gpio_set(struct gpio_chip *chip, unsigned offset, int value);
+
+#define NCT5104D_GPIO_BANK(_base, _ngpio, _regbase)			\
+	{								\
+		.chip = {						\
+			.label            = DRVNAME,			\
+			.owner            = THIS_MODULE,		\
+			.direction_input  = nct5104d_gpio_direction_in,	\
+			.get              = nct5104d_gpio_get,		\
+			.direction_output = nct5104d_gpio_direction_out,	\
+			.set              = nct5104d_gpio_set,		\
+			.base             = _base,			\
+			.ngpio            = _ngpio,			\
+			.can_sleep        = true,			\
+		},							\
+		.regbase = _regbase,					\
+	}
+
+#define gpio_dir(base) (base + 0)
+#define gpio_data(base) (base + 1)
+
+static struct nct5104d_gpio_bank nct5104d_gpio_bank[] = {
+	NCT5104D_GPIO_BANK(0 , 8, 0xE0),
+	NCT5104D_GPIO_BANK(10, 8, 0xE4)
+};
+
+static int nct5104d_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+	int err;
+	struct nct5104d_gpio_bank *bank =
+		container_of(chip, struct nct5104d_gpio_bank, chip);
+	struct nct5104d_sio *sio = bank->data->sio;
+	u8 dir;
+
+	err = superio_enter(sio->addr);
+	if (err)
+		return err;
+	superio_select(sio->addr, SIO_LD_GPIO);
+
+	dir = superio_inb(sio->addr, gpio_dir(bank->regbase));
+	dir |= (1 << offset);
+	superio_outb(sio->addr, gpio_dir(bank->regbase), dir);
+
+	superio_exit(sio->addr);
+
+	return 0;
+}
+
+static int nct5104d_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	int err;
+	struct nct5104d_gpio_bank *bank =
+		container_of(chip, struct nct5104d_gpio_bank, chip);
+	struct nct5104d_sio *sio = bank->data->sio;
+	u8 data;
+
+	err = superio_enter(sio->addr);
+	if (err)
+		return err;
+	superio_select(sio->addr, SIO_LD_GPIO);
+
+	data = superio_inb(sio->addr, gpio_data(bank->regbase));
+
+	superio_exit(sio->addr);
+
+	return !!(data & 1 << offset);
+}
+
+static int nct5104d_gpio_direction_out(struct gpio_chip *chip,
+				     unsigned offset, int value)
+{
+	int err;
+	struct nct5104d_gpio_bank *bank =
+		container_of(chip, struct nct5104d_gpio_bank, chip);
+	struct nct5104d_sio *sio = bank->data->sio;
+	u8 dir, data_out;
+
+	err = superio_enter(sio->addr);
+	if (err)
+		return err;
+	superio_select(sio->addr, SIO_LD_GPIO);
+
+	data_out = superio_inb(sio->addr, gpio_data(bank->regbase));
+	if (value)
+		data_out |= (1 << offset);
+	else
+		data_out &= ~(1 << offset);
+	superio_outb(sio->addr, gpio_data(bank->regbase), data_out);
+
+	dir = superio_inb(sio->addr, gpio_dir(bank->regbase));
+	dir &= ~(1 << offset);
+	superio_outb(sio->addr, gpio_dir(bank->regbase), dir);
+
+	superio_exit(sio->addr);
+
+	return 0;
+}
+
+static void nct5104d_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	int err;
+	struct nct5104d_gpio_bank *bank =
+		container_of(chip, struct nct5104d_gpio_bank, chip);
+	struct nct5104d_sio *sio = bank->data->sio;
+	u8 data_out;
+
+	err = superio_enter(sio->addr);
+	if (err)
+		return;
+	superio_select(sio->addr, SIO_LD_GPIO);
+
+	data_out = superio_inb(sio->addr, gpio_data(bank->regbase));
+	if (value)
+		data_out |= (1 << offset);
+	else
+		data_out &= ~(1 << offset);
+	superio_outb(sio->addr, gpio_data(bank->regbase), data_out);
+
+	superio_exit(sio->addr);
+}
+
+/*
+ * Platform device and driver.
+ */
+
+static int nct5104d_gpio_probe(struct platform_device *pdev)
+{
+	int err;
+	int i;
+	struct nct5104d_sio *sio = pdev->dev.platform_data;
+	struct nct5104d_gpio_data *data;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	switch (sio->type) {
+	case nct5104d:
+		data->nr_bank = ARRAY_SIZE(nct5104d_gpio_bank);
+		data->bank = nct5104d_gpio_bank;
+		break;
+	default:
+		return -ENODEV;
+	}
+	data->sio = sio;
+
+	platform_set_drvdata(pdev, data);
+
+	/* For each GPIO bank, register a GPIO chip. */
+	for (i = 0; i < data->nr_bank; i++) {
+		struct nct5104d_gpio_bank *bank = &data->bank[i];
+
+		bank->chip.dev = &pdev->dev;
+		bank->data = data;
+
+		err = gpiochip_add(&bank->chip);
+		if (err) {
+			dev_err(&pdev->dev,
+				"Failed to register gpiochip %d: %d\n",
+				i, err);
+			goto err_gpiochip;
+		}
+	}
+
+	return 0;
+
+err_gpiochip:
+	for (i = i - 1; i >= 0; i--) {
+		struct nct5104d_gpio_bank *bank = &data->bank[i];
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)
+		int rm_err = gpiochip_remove(&bank->chip);
+		if (rm_err < 0)
+			dev_err(&pdev->dev,
+				"Failed to remove gpiochip %d: %d\n",
+				i, rm_err);
+#else /* LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) */
+		gpiochip_remove (&bank->chip);
+#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) */
+	}
+
+	return err;
+}
+
+static int nct5104d_gpio_remove(struct platform_device *pdev)
+{
+	int i;
+	struct nct5104d_gpio_data *data = platform_get_drvdata(pdev);
+
+	for (i = 0; i < data->nr_bank; i++) {
+		struct nct5104d_gpio_bank *bank = &data->bank[i];
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)
+		int err = gpiochip_remove(&bank->chip);
+		if (err) {
+			dev_err(&pdev->dev,
+				"Failed to remove GPIO gpiochip %d: %d\n",
+				i, err);
+			return err;
+		}
+#else /* LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) */
+		gpiochip_remove (&bank->chip);
+#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0) */
+	}
+
+	return 0;
+}
+
+static int __init nct5104d_find(int addr, struct nct5104d_sio *sio)
+{
+	int err;
+	u16 devid;
+	u8 gpio_cfg;
+
+	err = superio_enter(addr);
+	if (err)
+		return err;
+
+	err = -ENODEV;
+
+	devid = superio_inw(addr, SIO_CHIPID);
+	switch (devid) {
+	case SIO_NCT5104D_ID:
+	case SIO_PCENGINES_APU_NCT5104D_ID:
+		sio->type = nct5104d;
+		/* enable GPIO0 and GPIO1 */
+		superio_select(addr, SIO_LD_GPIO);
+		gpio_cfg = superio_inb(addr, SIO_GPIO_ENABLE);
+		gpio_cfg |= 0x03;
+		superio_outb(addr, SIO_GPIO_ENABLE, gpio_cfg);
+		break;
+	default:
+		pr_info(DRVNAME ": Unsupported device 0x%04x\n", devid);
+		goto err;
+	}
+	sio->addr = addr;
+	err = 0;
+
+	pr_info(DRVNAME ": Found %s at %#x chip id 0x%04x\n",
+		nct5104d_names[sio->type],
+		(unsigned int) addr,
+		(int) superio_inw(addr, SIO_CHIPID));
+
+        superio_select(sio->addr, SIO_LD_GPIO_MODE);
+        superio_outb(sio->addr, SIO_GPIO1_MODE, 0x0);
+        superio_outb(sio->addr, SIO_GPIO2_MODE, 0x0);
+
+err:
+	superio_exit(addr);
+	return err;
+}
+
+static struct platform_device *nct5104d_gpio_pdev;
+
+static int __init
+nct5104d_gpio_device_add(const struct nct5104d_sio *sio)
+{
+	int err;
+
+	nct5104d_gpio_pdev = platform_device_alloc(DRVNAME, -1);
+	if (!nct5104d_gpio_pdev)
+		pr_err(DRVNAME ": Error platform_device_alloc\n");
+	if (!nct5104d_gpio_pdev)
+		return -ENOMEM;
+
+	err = platform_device_add_data(nct5104d_gpio_pdev,
+				       sio, sizeof(*sio));
+	if (err) {
+		pr_err(DRVNAME "Platform data allocation failed\n");
+		goto err;
+	}
+
+	err = platform_device_add(nct5104d_gpio_pdev);
+	if (err) {
+		pr_err(DRVNAME "Device addition failed\n");
+		goto err;
+	}
+	pr_info(DRVNAME ": Device added\n");
+	return 0;
+
+err:
+	platform_device_put(nct5104d_gpio_pdev);
+
+	return err;
+}
+
+/*
+ */
+
+static struct platform_driver nct5104d_gpio_driver = {
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= DRVNAME,
+	},
+	.probe		= nct5104d_gpio_probe,
+	.remove		= nct5104d_gpio_remove,
+};
+
+static int __init nct5104d_gpio_init(void)
+{
+	int err;
+	struct nct5104d_sio sio;
+	const char *board_vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
+	const char *board_name = dmi_get_system_info(DMI_BOARD_NAME);
+
+ 	/* Make sure we only run on PC Engine APU boards */
+	if (!board_name || !board_vendor || strcasecmp(board_vendor, "PC Engines") || strncasecmp(board_name, "apu", 3)) {
+		return -ENODEV;
+	}
+
+	if (nct5104d_find(0x2e, &sio) &&
+	    nct5104d_find(0x4e, &sio))
+		return -ENODEV;
+
+	err = platform_driver_register(&nct5104d_gpio_driver);
+	if (!err) {
+		pr_info(DRVNAME ": platform_driver_register\n");
+		err = nct5104d_gpio_device_add(&sio);
+		if (err)
+			platform_driver_unregister(&nct5104d_gpio_driver);
+	}
+
+	return err;
+}
+subsys_initcall(nct5104d_gpio_init);
+
+static void __exit nct5104d_gpio_exit(void)
+{
+	platform_device_unregister(nct5104d_gpio_pdev);
+	platform_driver_unregister(&nct5104d_gpio_driver);
+}
+module_exit(nct5104d_gpio_exit);
+
+MODULE_DESCRIPTION("GPIO driver for Super-I/O chips NCT5104D");
+MODULE_AUTHOR("Tasanakorn Phaipool <tasanakorn@gmail.com>");
+MODULE_LICENSE("GPL");