platform/x86: Add Asus TF103C dock driver

Add a driver for the keyboard, touchpad and USB port of
the keyboard dock for the Asus TF103C 2-in-1 tablet.

This keyboard dock has its own I2C attached embedded controller
and the keyboard and touchpad are also connected over I2C,
instead of using the usual USB connection. This means that the
keyboard dock requires this special driver to function.

Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: Ion Agorria <ion@agorria.com>
Cc: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211226141849.156407-1-hdegoede@redhat.com

3 files changed, 965 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 833abec54644..c23612d98126 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -309,6 +309,25 @@ config ASUS_NB_WMI
 	  If you have an ACPI-WMI compatible Asus Notebook, say Y or M
 	  here.
 
+config ASUS_TF103C_DOCK
+	tristate "Asus TF103C 2-in-1 keyboard dock"
+	depends on ACPI
+	depends on I2C
+	depends on INPUT
+	depends on HID
+	depends on GPIOLIB
+	help
+	  This is a driver for the keyboard, touchpad and USB port of the
+	  keyboard dock for the Asus TF103C 2-in-1 tablet.
+
+	  This keyboard dock has its own I2C attached embedded controller
+	  and the keyboard and touchpad are also connected over I2C,
+	  instead of using the usual USB connection. This means that the
+	  keyboard dock requires this special driver to function.
+
+	  If you have an Asus TF103C tablet say Y or M here, for a generic x86
+	  distro config say M here.
+
 config MERAKI_MX100
 	tristate "Cisco Meraki MX100 Platform Driver"
 	depends on GPIOLIB
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index dce8a0e40e1b..c12a9b044fd8 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_ASUS_LAPTOP)	+= asus-laptop.o
 obj-$(CONFIG_ASUS_WIRELESS)	+= asus-wireless.o
 obj-$(CONFIG_ASUS_WMI)		+= asus-wmi.o
 obj-$(CONFIG_ASUS_NB_WMI)	+= asus-nb-wmi.o
+obj-$(CONFIG_ASUS_TF103C_DOCK)	+= asus-tf103c-dock.o
 obj-$(CONFIG_EEEPC_LAPTOP)	+= eeepc-laptop.o
 obj-$(CONFIG_EEEPC_WMI)		+= eeepc-wmi.o
 
diff --git a/drivers/platform/x86/asus-tf103c-dock.c b/drivers/platform/x86/asus-tf103c-dock.c
new file mode 100644
index 000000000000..d4ef8f362ee6
--- /dev/null
+++ b/drivers/platform/x86/asus-tf103c-dock.c
@@ -0,0 +1,945 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * This is a driver for the keyboard, touchpad and USB port of the
+ * keyboard dock for the Asus TF103C 2-in-1 tablet.
+ *
+ * This keyboard dock has its own I2C attached embedded controller
+ * and the keyboard and touchpad are also connected over I2C,
+ * instead of using the usual USB connection. This means that the
+ * keyboard dock requires this special driver to function.
+ *
+ * Copyright (C) 2021 Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/dmi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/machine.h>
+#include <linux/hid.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mod_devicetable.h>
+#include <linux/moduleparam.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/workqueue.h>
+#include <asm/unaligned.h>
+
+static bool fnlock;
+module_param(fnlock, bool, 0644);
+MODULE_PARM_DESC(fnlock,
+		 "By default the kbd toprow sends multimedia key presses. AltGr "
+		 "can be pressed to change this to F1-F12. Set this to 1 to "
+		 "change the default. Press AltGr + Esc to toggle at runtime.");
+
+#define TF103C_DOCK_DEV_NAME				"NPCE69A:00"
+
+#define TF103C_DOCK_HPD_DEBOUNCE			msecs_to_jiffies(20)
+
+/*** Touchpad I2C device defines ***/
+#define TF103C_DOCK_TP_ADDR				0x15
+
+/*** Keyboard I2C device defines **A*/
+#define TF103C_DOCK_KBD_ADDR				0x16
+
+#define TF103C_DOCK_KBD_DATA_REG			0x73
+#define TF103C_DOCK_KBD_DATA_MIN_LENGTH			4
+#define TF103C_DOCK_KBD_DATA_MAX_LENGTH			11
+#define TF103C_DOCK_KBD_DATA_MODIFIERS			3
+#define TF103C_DOCK_KBD_DATA_KEYS			5
+#define TF103C_DOCK_KBD_CMD_REG				0x75
+
+#define TF103C_DOCK_KBD_CMD_ENABLE			0x0800
+
+/*** EC innterrupt data I2C device defines ***/
+#define TF103C_DOCK_INTR_ADDR				0x19
+#define TF103C_DOCK_INTR_DATA_REG			0x6a
+
+#define TF103C_DOCK_INTR_DATA1_OBF_MASK			0x01
+#define TF103C_DOCK_INTR_DATA1_KEY_MASK			0x04
+#define TF103C_DOCK_INTR_DATA1_KBC_MASK			0x08
+#define TF103C_DOCK_INTR_DATA1_AUX_MASK			0x20
+#define TF103C_DOCK_INTR_DATA1_SCI_MASK			0x40
+#define TF103C_DOCK_INTR_DATA1_SMI_MASK			0x80
+/* Special values for the OOB data on kbd_client / tp_client */
+#define TF103C_DOCK_INTR_DATA1_OOB_VALUE		0xc1
+#define TF103C_DOCK_INTR_DATA2_OOB_VALUE		0x04
+
+#define TF103C_DOCK_SMI_AC_EVENT			0x31
+#define TF103C_DOCK_SMI_HANDSHAKING			0x50
+#define TF103C_DOCK_SMI_EC_WAKEUP			0x53
+#define TF103C_DOCK_SMI_BOOTBLOCK_RESET			0x5e
+#define TF103C_DOCK_SMI_WATCHDOG_RESET			0x5f
+#define TF103C_DOCK_SMI_ADAPTER_CHANGE			0x60
+#define TF103C_DOCK_SMI_DOCK_INSERT			0x61
+#define TF103C_DOCK_SMI_DOCK_REMOVE			0x62
+#define TF103C_DOCK_SMI_PAD_BL_CHANGE			0x63
+#define TF103C_DOCK_SMI_HID_STATUS_CHANGED		0x64
+#define TF103C_DOCK_SMI_HID_WAKEUP			0x65
+#define TF103C_DOCK_SMI_S3				0x83
+#define TF103C_DOCK_SMI_S5				0x85
+#define TF103C_DOCK_SMI_NOTIFY_SHUTDOWN			0x90
+#define TF103C_DOCK_SMI_RESUME				0x91
+
+/*** EC (dockram) I2C device defines ***/
+#define TF103C_DOCK_EC_ADDR				0x1b
+
+#define TF103C_DOCK_EC_CMD_REG				0x0a
+#define TF103C_DOCK_EC_CMD_LEN				9
+
+enum {
+	TF103C_DOCK_FLAG_HID_OPEN,
+};
+
+struct tf103c_dock_data {
+	struct delayed_work hpd_work;
+	struct irq_chip tp_irqchip;
+	struct irq_domain *tp_irq_domain;
+	struct i2c_client *ec_client;
+	struct i2c_client *intr_client;
+	struct i2c_client *kbd_client;
+	struct i2c_client *tp_client;
+	struct gpio_desc *pwr_en;
+	struct gpio_desc *irq_gpio;
+	struct gpio_desc *hpd_gpio;
+	struct input_dev *input;
+	struct hid_device *hid;
+	unsigned long flags;
+	int board_rev;
+	int irq;
+	int hpd_irq;
+	int tp_irq;
+	int last_press_0x13;
+	int last_press_0x14;
+	bool enabled;
+	bool tp_enabled;
+	bool altgr_pressed;
+	bool esc_pressed;
+	bool filter_esc;
+	u8 kbd_buf[TF103C_DOCK_KBD_DATA_MAX_LENGTH];
+};
+
+static struct gpiod_lookup_table tf103c_dock_gpios = {
+	.dev_id = "i2c-" TF103C_DOCK_DEV_NAME,
+	.table = {
+		GPIO_LOOKUP("INT33FC:00",      55, "dock_pwr_en", GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP("INT33FC:02",       1, "dock_irq", GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP("INT33FC:02",      29, "dock_hpd", GPIO_ACTIVE_HIGH),
+		GPIO_LOOKUP("gpio_crystalcove", 2, "board_rev", GPIO_ACTIVE_HIGH),
+		{}
+	},
+};
+
+/* Byte 0 is the length of the rest of the packet */
+static const u8 tf103c_dock_enable_cmd[9] = { 8, 0x20, 0, 0, 0, 0, 0x20, 0, 0 };
+static const u8 tf103c_dock_usb_enable_cmd[9] = { 8, 0, 0, 0, 0, 0, 0, 0x40, 0 };
+static const u8 tf103c_dock_suspend_cmd[9] = { 8, 0, 0x20, 0, 0, 0x22, 0, 0, 0 };
+
+/*** keyboard related code ***/
+
+static u8 tf103c_dock_kbd_hid_desc[] = {
+	0x05, 0x01,         /*  Usage Page (Desktop),               */
+	0x09, 0x06,         /*  Usage (Keyboard),                   */
+	0xA1, 0x01,         /*  Collection (Application),           */
+	0x85, 0x11,         /*      Report ID (17),                 */
+	0x95, 0x08,         /*      Report Count (8),               */
+	0x75, 0x01,         /*      Report Size (1),                */
+	0x15, 0x00,         /*      Logical Minimum (0),            */
+	0x25, 0x01,         /*      Logical Maximum (1),            */
+	0x05, 0x07,         /*      Usage Page (Keyboard),          */
+	0x19, 0xE0,         /*      Usage Minimum (KB Leftcontrol), */
+	0x29, 0xE7,         /*      Usage Maximum (KB Right GUI),   */
+	0x81, 0x02,         /*      Input (Variable),               */
+	0x95, 0x01,         /*      Report Count (1),               */
+	0x75, 0x08,         /*      Report Size (8),                */
+	0x81, 0x01,         /*      Input (Constant),               */
+	0x95, 0x06,         /*      Report Count (6),               */
+	0x75, 0x08,         /*      Report Size (8),                */
+	0x15, 0x00,         /*      Logical Minimum (0),            */
+	0x26, 0xFF, 0x00,   /*      Logical Maximum (255),          */
+	0x05, 0x07,         /*      Usage Page (Keyboard),          */
+	0x19, 0x00,         /*      Usage Minimum (None),           */
+	0x2A, 0xFF, 0x00,   /*      Usage Maximum (FFh),            */
+	0x81, 0x00,         /*      Input,                          */
+	0xC0                /*  End Collection                      */
+};
+
+static int tf103c_dock_kbd_read(struct tf103c_dock_data *dock)
+{
+	struct i2c_client *client = dock->kbd_client;
+	struct device *dev = &dock->ec_client->dev;
+	struct i2c_msg msgs[2];
+	u8 reg[2];
+	int ret;
+
+	reg[0] = TF103C_DOCK_KBD_DATA_REG & 0xff;
+	reg[1] = TF103C_DOCK_KBD_DATA_REG >> 8;
+
+	msgs[0].addr = client->addr;
+	msgs[0].flags = 0;
+	msgs[0].len = sizeof(reg);
+	msgs[0].buf = reg;
+
+	msgs[1].addr = client->addr;
+	msgs[1].flags = I2C_M_RD;
+	msgs[1].len = TF103C_DOCK_KBD_DATA_MAX_LENGTH;
+	msgs[1].buf = dock->kbd_buf;
+
+	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	if (ret != ARRAY_SIZE(msgs)) {
+		dev_err(dev, "error %d reading kbd data\n", ret);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void tf103c_dock_kbd_write(struct tf103c_dock_data *dock, u16 cmd)
+{
+	struct device *dev = &dock->ec_client->dev;
+	u8 buf[4];
+	int ret;
+
+	put_unaligned_le16(TF103C_DOCK_KBD_CMD_REG, &buf[0]);
+	put_unaligned_le16(cmd, &buf[2]);
+
+	ret = i2c_master_send(dock->kbd_client, buf, sizeof(buf));
+	if (ret != sizeof(buf))
+		dev_err(dev, "error %d writing kbd cmd\n", ret);
+}
+
+/* HID ll_driver functions for forwarding input-reports from the kbd_client */
+static int tf103c_dock_hid_parse(struct hid_device *hid)
+{
+	return hid_parse_report(hid, tf103c_dock_kbd_hid_desc,
+				sizeof(tf103c_dock_kbd_hid_desc));
+}
+
+static int tf103c_dock_hid_start(struct hid_device *hid)
+{
+	return 0;
+}
+
+static void tf103c_dock_hid_stop(struct hid_device *hid)
+{
+	hid->claimed = 0;
+}
+
+static int tf103c_dock_hid_open(struct hid_device *hid)
+{
+	struct tf103c_dock_data *dock = hid->driver_data;
+
+	set_bit(TF103C_DOCK_FLAG_HID_OPEN, &dock->flags);
+	return 0;
+}
+
+static void tf103c_dock_hid_close(struct hid_device *hid)
+{
+	struct tf103c_dock_data *dock = hid->driver_data;
+
+	clear_bit(TF103C_DOCK_FLAG_HID_OPEN, &dock->flags);
+}
+
+/* Mandatory, but not used */
+static int tf103c_dock_hid_raw_request(struct hid_device *hid, u8 reportnum,
+				       u8 *buf, size_t len, u8 rtype, int reqtype)
+{
+	return 0;
+}
+
+struct hid_ll_driver tf103c_dock_hid_ll_driver = {
+	.parse = tf103c_dock_hid_parse,
+	.start = tf103c_dock_hid_start,
+	.stop = tf103c_dock_hid_stop,
+	.open = tf103c_dock_hid_open,
+	.close = tf103c_dock_hid_close,
+	.raw_request = tf103c_dock_hid_raw_request,
+};
+
+static int tf103c_dock_toprow_codes[13][2] = {
+	/* Normal,            AltGr pressed */
+	{ KEY_POWER,          KEY_F1 },
+	{ KEY_RFKILL,         KEY_F2 },
+	{ KEY_F21,            KEY_F3 }, /* Touchpad toggle, userspace expects F21 */
+	{ KEY_BRIGHTNESSDOWN, KEY_F4 },
+	{ KEY_BRIGHTNESSUP,   KEY_F5 },
+	{ KEY_CAMERA,         KEY_F6 },
+	{ KEY_CONFIG,         KEY_F7 },
+	{ KEY_PREVIOUSSONG,   KEY_F8 },
+	{ KEY_PLAYPAUSE,      KEY_F9 },
+	{ KEY_NEXTSONG,       KEY_F10 },
+	{ KEY_MUTE,           KEY_F11 },
+	{ KEY_VOLUMEDOWN,     KEY_F12 },
+	{ KEY_VOLUMEUP,       KEY_SYSRQ },
+};
+
+static void tf103c_dock_report_toprow_kbd_hook(struct tf103c_dock_data *dock)
+{
+	u8 *esc, *buf = dock->kbd_buf;
+	int size;
+
+	/*
+	 * Stop AltGr reports from getting reported on the "Asus TF103C Dock
+	 * Keyboard" input_dev, since this gets used as "Fn" key for the toprow
+	 * keys. Instead we report this on the "Asus TF103C Dock Top Row Keys"
+	 * input_dev, when not used to modify the toprow keys.
+	 */
+	dock->altgr_pressed = buf[TF103C_DOCK_KBD_DATA_MODIFIERS] & 0x40;
+	buf[TF103C_DOCK_KBD_DATA_MODIFIERS] &= ~0x40;
+
+	input_report_key(dock->input, KEY_RIGHTALT, dock->altgr_pressed);
+	input_sync(dock->input);
+
+	/* Toggle fnlock on AltGr + Esc press */
+	buf = buf + TF103C_DOCK_KBD_DATA_KEYS;
+	size = TF103C_DOCK_KBD_DATA_MAX_LENGTH - TF103C_DOCK_KBD_DATA_KEYS;
+	esc = memchr(buf, 0x29, size);
+	if (!dock->esc_pressed && esc) {
+		if (dock->altgr_pressed) {
+			fnlock = !fnlock;
+			dock->filter_esc = true;
+		}
+	}
+	if (esc && dock->filter_esc)
+		*esc = 0;
+	else
+		dock->filter_esc = false;
+
+	dock->esc_pressed = esc != NULL;
+}
+
+static void tf103c_dock_toprow_press(struct tf103c_dock_data *dock, int key_code)
+{
+	/*
+	 * Release AltGr before reporting the toprow key, so that userspace
+	 * sees e.g. just KEY_SUSPEND and not AltGr + KEY_SUSPEND.
+	 */
+	if (dock->altgr_pressed) {
+		input_report_key(dock->input, KEY_RIGHTALT, false);
+		input_sync(dock->input);
+	}
+
+	input_report_key(dock->input, key_code, true);
+	input_sync(dock->input);
+}
+
+static void tf103c_dock_toprow_release(struct tf103c_dock_data *dock, int key_code)
+{
+	input_report_key(dock->input, key_code, false);
+	input_sync(dock->input);
+
+	if (dock->altgr_pressed) {
+		input_report_key(dock->input, KEY_RIGHTALT, true);
+		input_sync(dock->input);
+	}
+}
+
+static void tf103c_dock_toprow_event(struct tf103c_dock_data *dock,
+					    int toprow_index, int *last_press)
+{
+	int key_code, fn = dock->altgr_pressed ^ fnlock;
+
+	if (last_press && *last_press) {
+		tf103c_dock_toprow_release(dock, *last_press);
+		*last_press = 0;
+	}
+
+	if (toprow_index < 0)
+		return;
+
+	key_code = tf103c_dock_toprow_codes[toprow_index][fn];
+	tf103c_dock_toprow_press(dock, key_code);
+
+	if (last_press)
+		*last_press = key_code;
+	else
+		tf103c_dock_toprow_release(dock, key_code);
+}
+
+/*
+ * The keyboard sends what appears to be standard I2C-HID input-reports,
+ * except that a 16 bit register address of where the I2C-HID format
+ * input-reports are stored must be send before reading it in a single
+ * (I2C repeated-start) I2C transaction.
+ *
+ * Its unknown how to get the HID descriptors but they are easy to reconstruct:
+ *
+ * Input report id 0x11 is 8 bytes long and contain standard USB HID intf-class,
+ * Boot Interface Subclass reports.
+ * Input report id 0x13 is 2 bytes long and sends Consumer Control events
+ * Input report id 0x14 is 1 byte long and sends System Control events
+ *
+ * However the top row keys (where a normal keyboard has F1-F12 + Print-Screen)
+ * are a mess, using a mix of the 0x13 and 0x14 input reports as well as EC SCI
+ * events; and these need special handling to allow actually sending F1-F12,
+ * since the Fn key on the keyboard only works on the cursor keys and the top
+ * row keys always send their special "Multimedia hotkey" codes.
+ *
+ * So only forward the 0x11 reports to HID and handle the top-row keys here.
+ */
+static void tf103c_dock_kbd_interrupt(struct tf103c_dock_data *dock)
+{
+	struct device *dev = &dock->ec_client->dev;
+	u8 *buf = dock->kbd_buf;
+	int size;
+
+	if (tf103c_dock_kbd_read(dock))
+		return;
+
+	size = buf[0] | buf[1] << 8;
+	if (size < TF103C_DOCK_KBD_DATA_MIN_LENGTH ||
+	    size > TF103C_DOCK_KBD_DATA_MAX_LENGTH) {
+		dev_err(dev, "error reported kbd pkt size %d is out of range %d-%d\n", size,
+			TF103C_DOCK_KBD_DATA_MIN_LENGTH,
+			TF103C_DOCK_KBD_DATA_MAX_LENGTH);
+		return;
+	}
+
+	switch (buf[2]) {
+	case 0x11:
+		if (size != 11)
+			break;
+
+		tf103c_dock_report_toprow_kbd_hook(dock);
+
+		if (test_bit(TF103C_DOCK_FLAG_HID_OPEN, &dock->flags))
+			hid_input_report(dock->hid, HID_INPUT_REPORT, buf + 2, size - 2, 1);
+		return;
+	case 0x13:
+		if (size != 5)
+			break;
+
+		switch (buf[3] | buf[4] << 8) {
+		case 0:
+			tf103c_dock_toprow_event(dock, -1, &dock->last_press_0x13);
+			return;
+		case 0x70:
+			tf103c_dock_toprow_event(dock, 3, &dock->last_press_0x13);
+			return;
+		case 0x6f:
+			tf103c_dock_toprow_event(dock, 4, &dock->last_press_0x13);
+			return;
+		case 0xb6:
+			tf103c_dock_toprow_event(dock, 7, &dock->last_press_0x13);
+			return;
+		case 0xcd:
+			tf103c_dock_toprow_event(dock, 8, &dock->last_press_0x13);
+			return;
+		case 0xb5:
+			tf103c_dock_toprow_event(dock, 9, &dock->last_press_0x13);
+			return;
+		case 0xe2:
+			tf103c_dock_toprow_event(dock, 10, &dock->last_press_0x13);
+			return;
+		case 0xea:
+			tf103c_dock_toprow_event(dock, 11, &dock->last_press_0x13);
+			return;
+		case 0xe9:
+			tf103c_dock_toprow_event(dock, 12, &dock->last_press_0x13);
+			return;
+		}
+		break;
+	case 0x14:
+		if (size != 4)
+			break;
+
+		switch (buf[3]) {
+		case 0:
+			tf103c_dock_toprow_event(dock, -1, &dock->last_press_0x14);
+			return;
+		case 1:
+			tf103c_dock_toprow_event(dock, 0, &dock->last_press_0x14);
+			return;
+		}
+		break;
+	}
+
+	dev_warn(dev, "warning unknown kbd data: %*ph\n", size, buf);
+}
+
+/*** touchpad related code ***/
+
+static const struct property_entry tf103c_dock_touchpad_props[] = {
+	PROPERTY_ENTRY_BOOL("elan,clickpad"),
+	{ }
+};
+
+static const struct software_node tf103c_dock_touchpad_sw_node = {
+	.properties = tf103c_dock_touchpad_props,
+};
+
+/*
+ * tf103c_enable_touchpad() is only called from the threaded interrupt handler
+ * and tf103c_disable_touchpad() is only called after the irq is disabled,
+ * so no locking is necessary.
+ */
+static void tf103c_dock_enable_touchpad(struct tf103c_dock_data *dock)
+{
+	struct i2c_board_info board_info = { };
+	struct device *dev = &dock->ec_client->dev;
+	int ret;
+
+	if (dock->tp_enabled) {
+		/* Happens after resume, the tp needs to be reinitialized */
+		ret = device_reprobe(&dock->tp_client->dev);
+		if (ret)
+			dev_err_probe(dev, ret, "reprobing tp-client\n");
+		return;
+	}
+
+	strscpy(board_info.type, "elan_i2c", I2C_NAME_SIZE);
+	board_info.addr = TF103C_DOCK_TP_ADDR;
+	board_info.dev_name = TF103C_DOCK_DEV_NAME "-tp";
+	board_info.irq = dock->tp_irq;
+	board_info.swnode = &tf103c_dock_touchpad_sw_node;
+
+	dock->tp_client = i2c_new_client_device(dock->ec_client->adapter, &board_info);
+	if (IS_ERR(dock->tp_client)) {
+		dev_err(dev, "error %ld creating tp client\n", PTR_ERR(dock->tp_client));
+		return;
+	}
+
+	dock->tp_enabled = true;
+}
+
+static void tf103c_dock_disable_touchpad(struct tf103c_dock_data *dock)
+{
+	if (!dock->tp_enabled)
+		return;
+
+	i2c_unregister_device(dock->tp_client);
+
+	dock->tp_enabled = false;
+}
+
+/*** interrupt handling code ***/
+static void tf103c_dock_ec_cmd(struct tf103c_dock_data *dock, const u8 *cmd)
+{
+	struct device *dev = &dock->ec_client->dev;
+	int ret;
+
+	ret = i2c_smbus_write_i2c_block_data(dock->ec_client, TF103C_DOCK_EC_CMD_REG,
+					     TF103C_DOCK_EC_CMD_LEN, cmd);
+	if (ret)
+		dev_err(dev, "error %d sending %*ph cmd\n", ret,
+			TF103C_DOCK_EC_CMD_LEN, cmd);
+}
+
+static void tf103c_dock_sci(struct tf103c_dock_data *dock, u8 val)
+{
+	struct device *dev = &dock->ec_client->dev;
+
+	switch (val) {
+	case 2:
+		tf103c_dock_toprow_event(dock, 1, NULL);
+		return;
+	case 4:
+		tf103c_dock_toprow_event(dock, 2, NULL);
+		return;
+	case 8:
+		tf103c_dock_toprow_event(dock, 5, NULL);
+		return;
+	case 17:
+		tf103c_dock_toprow_event(dock, 6, NULL);
+		return;
+	}
+
+	dev_warn(dev, "warning unknown SCI value: 0x%02x\n", val);
+}
+
+static void tf103c_dock_smi(struct tf103c_dock_data *dock, u8 val)
+{
+	struct device *dev = &dock->ec_client->dev;
+
+	switch (val) {
+	case TF103C_DOCK_SMI_EC_WAKEUP:
+		tf103c_dock_ec_cmd(dock, tf103c_dock_enable_cmd);
+		tf103c_dock_ec_cmd(dock, tf103c_dock_usb_enable_cmd);
+		tf103c_dock_kbd_write(dock, TF103C_DOCK_KBD_CMD_ENABLE);
+		break;
+	case TF103C_DOCK_SMI_PAD_BL_CHANGE:
+		/* There is no backlight, but the EC still sends this */
+		break;
+	case TF103C_DOCK_SMI_HID_STATUS_CHANGED:
+		tf103c_dock_enable_touchpad(dock);
+		break;
+	default:
+		dev_warn(dev, "warning unknown SMI value: 0x%02x\n", val);
+		break;
+	}
+}
+
+static irqreturn_t tf103c_dock_irq(int irq, void *data)
+{
+	struct tf103c_dock_data *dock = data;
+	struct device *dev = &dock->ec_client->dev;
+	u8 intr_data[8];
+	int ret;
+
+	ret = i2c_smbus_read_i2c_block_data(dock->intr_client, TF103C_DOCK_INTR_DATA_REG,
+					    sizeof(intr_data), intr_data);
+	if (ret != sizeof(intr_data)) {
+		dev_err(dev, "error %d reading intr data\n", ret);
+		return IRQ_NONE;
+	}
+
+	if (!(intr_data[1] & TF103C_DOCK_INTR_DATA1_OBF_MASK))
+		return IRQ_NONE;
+
+	/* intr_data[0] is the length of the rest of the packet */
+	if (intr_data[0] == 3 && intr_data[1] == TF103C_DOCK_INTR_DATA1_OOB_VALUE &&
+				 intr_data[2] == TF103C_DOCK_INTR_DATA2_OOB_VALUE) {
+		/* intr_data[3] seems to contain a HID input report id */
+		switch (intr_data[3]) {
+		case 0x01:
+			handle_nested_irq(dock->tp_irq);
+			break;
+		case 0x11:
+		case 0x13:
+		case 0x14:
+			tf103c_dock_kbd_interrupt(dock);
+			break;
+		default:
+			dev_warn(dev, "warning unknown intr_data[3]: 0x%02x\n", intr_data[3]);
+			break;
+		}
+		return IRQ_HANDLED;
+	}
+
+	if (intr_data[1] & TF103C_DOCK_INTR_DATA1_SCI_MASK) {
+		tf103c_dock_sci(dock, intr_data[2]);
+		return IRQ_HANDLED;
+	}
+
+	if (intr_data[1] & TF103C_DOCK_INTR_DATA1_SMI_MASK) {
+		tf103c_dock_smi(dock, intr_data[2]);
+		return IRQ_HANDLED;
+	}
+
+	dev_warn(dev, "warning unknown intr data: %*ph\n", 8, intr_data);
+	return IRQ_NONE;
+}
+
+/*
+ * tf103c_dock_[dis|en]able only run from hpd_work or at times when
+ * hpd_work cannot run (hpd_irq disabled), so no locking is necessary.
+ */
+static void tf103c_dock_enable(struct tf103c_dock_data *dock)
+{
+	if (dock->enabled)
+		return;
+
+	if (dock->board_rev != 2)
+		gpiod_set_value(dock->pwr_en, 1);
+
+	msleep(500);
+	enable_irq(dock->irq);
+
+	dock->enabled = true;
+}
+
+static void tf103c_dock_disable(struct tf103c_dock_data *dock)
+{
+	if (!dock->enabled)
+		return;
+
+	disable_irq(dock->irq);
+	tf103c_dock_disable_touchpad(dock);
+	if (dock->board_rev != 2)
+		gpiod_set_value(dock->pwr_en, 0);
+
+	dock->enabled = false;
+}
+
+static void tf103c_dock_hpd_work(struct work_struct *work)
+{
+	struct tf103c_dock_data *dock =
+		container_of(work, struct tf103c_dock_data, hpd_work.work);
+
+	if (gpiod_get_value(dock->hpd_gpio))
+		tf103c_dock_enable(dock);
+	else
+		tf103c_dock_disable(dock);
+}
+
+static irqreturn_t tf103c_dock_hpd_irq(int irq, void *data)
+{
+	struct tf103c_dock_data *dock = data;
+
+	mod_delayed_work(system_long_wq, &dock->hpd_work, TF103C_DOCK_HPD_DEBOUNCE);
+	return IRQ_HANDLED;
+}
+
+static void tf103c_dock_start_hpd(struct tf103c_dock_data *dock)
+{
+	enable_irq(dock->hpd_irq);
+	/* Sync current HPD status */
+	queue_delayed_work(system_long_wq, &dock->hpd_work, TF103C_DOCK_HPD_DEBOUNCE);
+}
+
+static void tf103c_dock_stop_hpd(struct tf103c_dock_data *dock)
+{
+	disable_irq(dock->hpd_irq);
+	cancel_delayed_work_sync(&dock->hpd_work);
+}
+
+/*** probe ***/
+
+static const struct dmi_system_id tf103c_dock_dmi_ids[] = {
+	{
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "TF103C"),
+		},
+	},
+	{ }
+};
+
+static void tf103c_dock_non_devm_cleanup(void *data)
+{
+	struct tf103c_dock_data *dock = data;
+
+	if (dock->tp_irq_domain)
+		irq_domain_remove(dock->tp_irq_domain);
+
+	if (!IS_ERR_OR_NULL(dock->hid))
+		hid_destroy_device(dock->hid);
+
+	i2c_unregister_device(dock->kbd_client);
+	i2c_unregister_device(dock->intr_client);
+	gpiod_remove_lookup_table(&tf103c_dock_gpios);
+}
+
+static int tf103c_dock_probe(struct i2c_client *client)
+{
+	struct i2c_board_info board_info = { };
+	struct device *dev = &client->dev;
+	struct gpio_desc *board_rev_gpio;
+	struct tf103c_dock_data *dock;
+	enum gpiod_flags flags;
+	int i, ret;
+
+	/* GPIOs are hardcoded for the Asus TF103C, don't bind on other devs */
+	if (!dmi_check_system(tf103c_dock_dmi_ids))
+		return -ENODEV;
+
+	dock = devm_kzalloc(dev, sizeof(*dock), GFP_KERNEL);
+	if (!dock)
+		return -ENOMEM;
+
+	INIT_DELAYED_WORK(&dock->hpd_work, tf103c_dock_hpd_work);
+
+	/* 1. Get GPIOs and their IRQs */
+	gpiod_add_lookup_table(&tf103c_dock_gpios);
+
+	ret = devm_add_action_or_reset(dev, tf103c_dock_non_devm_cleanup, dock);
+	if (ret)
+		return ret;
+
+	/*
+	 * The pin is configured as input by default, use ASIS because otherwise
+	 * the gpio-crystalcove.c switches off the internal pull-down replacing
+	 * it with a pull-up.
+	 */
+	board_rev_gpio = gpiod_get(dev, "board_rev", GPIOD_ASIS);
+	if (IS_ERR(board_rev_gpio))
+		return dev_err_probe(dev, PTR_ERR(board_rev_gpio), "requesting board_rev GPIO\n");
+	dock->board_rev = gpiod_get_value_cansleep(board_rev_gpio) + 1;
+	gpiod_put(board_rev_gpio);
+
+	/*
+	 * The Android driver drives the dock-pwr-en pin high at probe for
+	 * revision 2 boards and then never touches it again?
+	 * This code has only been tested on a revision 1 board, so for now
+	 * just mimick what Android does on revision 2 boards.
+	 */
+	flags = (dock->board_rev == 2) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+	dock->pwr_en = devm_gpiod_get(dev, "dock_pwr_en", flags);
+	if (IS_ERR(dock->pwr_en))
+		return dev_err_probe(dev, PTR_ERR(dock->pwr_en), "requesting pwr_en GPIO\n");
+
+	dock->irq_gpio = devm_gpiod_get(dev, "dock_irq", GPIOD_IN);
+	if (IS_ERR(dock->irq_gpio))
+		return dev_err_probe(dev, PTR_ERR(dock->irq_gpio), "requesting IRQ GPIO\n");
+
+	dock->irq = gpiod_to_irq(dock->irq_gpio);
+	if (dock->irq < 0)
+		return dev_err_probe(dev, dock->irq, "getting dock IRQ");
+
+	ret = devm_request_threaded_irq(dev, dock->irq, NULL, tf103c_dock_irq,
+					IRQF_TRIGGER_LOW | IRQF_ONESHOT | IRQF_NO_AUTOEN,
+					"dock_irq", dock);
+	if (ret)
+		return dev_err_probe(dev, ret, "requesting dock IRQ");
+
+	dock->hpd_gpio = devm_gpiod_get(dev, "dock_hpd", GPIOD_IN);
+	if (IS_ERR(dock->hpd_gpio))
+		return dev_err_probe(dev, PTR_ERR(dock->hpd_gpio), "requesting HPD GPIO\n");
+
+	dock->hpd_irq = gpiod_to_irq(dock->hpd_gpio);
+	if (dock->hpd_irq < 0)
+		return dev_err_probe(dev, dock->hpd_irq, "getting HPD IRQ");
+
+	ret = devm_request_irq(dev, dock->hpd_irq, tf103c_dock_hpd_irq,
+			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_NO_AUTOEN,
+			       "dock_hpd", dock);
+	if (ret)
+		return ret;
+
+	/*
+	 * 2. Create I2C clients. The dock uses 4 different i2c addresses,
+	 * the ACPI NPCE69A node being probed points to the EC address.
+	 */
+	dock->ec_client = client;
+
+	strscpy(board_info.type, "tf103c-dock-intr", I2C_NAME_SIZE);
+	board_info.addr = TF103C_DOCK_INTR_ADDR;
+	board_info.dev_name = TF103C_DOCK_DEV_NAME "-intr";
+
+	dock->intr_client = i2c_new_client_device(client->adapter, &board_info);
+	if (IS_ERR(dock->intr_client))
+		return dev_err_probe(dev, PTR_ERR(dock->intr_client), "creating intr client\n");
+
+	strscpy(board_info.type, "tf103c-dock-kbd", I2C_NAME_SIZE);
+	board_info.addr = TF103C_DOCK_KBD_ADDR;
+	board_info.dev_name = TF103C_DOCK_DEV_NAME "-kbd";
+
+	dock->kbd_client = i2c_new_client_device(client->adapter, &board_info);
+	if (IS_ERR(dock->kbd_client))
+		return dev_err_probe(dev, PTR_ERR(dock->kbd_client), "creating kbd client\n");
+
+	/* 3. Create input_dev for the top row of the keyboard */
+	dock->input = devm_input_allocate_device(dev);
+	if (!dock->input)
+		return -ENOMEM;
+
+	dock->input->name = "Asus TF103C Dock Top Row Keys";
+	dock->input->phys = dev_name(dev);
+	dock->input->dev.parent = dev;
+	dock->input->id.bustype = BUS_I2C;
+	dock->input->id.vendor = /* USB_VENDOR_ID_ASUSTEK */
+	dock->input->id.product = /* From TF-103-C */
+	dock->input->id.version = 0x0100;  /* 1.0 */
+
+	for (i = 0; i < ARRAY_SIZE(tf103c_dock_toprow_codes); i++) {
+		input_set_capability(dock->input, EV_KEY, tf103c_dock_toprow_codes[i][0]);
+		input_set_capability(dock->input, EV_KEY, tf103c_dock_toprow_codes[i][1]);
+	}
+	input_set_capability(dock->input, EV_KEY, KEY_RIGHTALT);
+
+	ret = input_register_device(dock->input);
+	if (ret)
+		return ret;
+
+	/* 4. Create HID device for the keyboard */
+	dock->hid = hid_allocate_device();
+	if (IS_ERR(dock->hid))
+		return dev_err_probe(dev, PTR_ERR(dock->hid), "allocating hid dev\n");
+
+	dock->hid->driver_data = dock;
+	dock->hid->ll_driver = &tf103c_dock_hid_ll_driver;
+	dock->hid->dev.parent = &client->dev;
+	dock->hid->bus = BUS_I2C;
+	dock->hid->vendor = 0x0b05;  /* USB_VENDOR_ID_ASUSTEK */
+	dock->hid->product = 0x0103; /* From TF-103-C */
+	dock->hid->version = 0x0100; /* 1.0 */
+	strscpy(dock->hid->name, "Asus TF103C Dock Keyboard", sizeof(dock->hid->name));
+	strscpy(dock->hid->phys, dev_name(dev), sizeof(dock->hid->phys));
+
+	ret = hid_add_device(dock->hid);
+	if (ret)
+		return dev_err_probe(dev, ret, "adding hid dev\n");
+
+	/* 5. Setup irqchip for touchpad IRQ pass-through */
+	dock->tp_irqchip.name = KBUILD_MODNAME;
+
+	dock->tp_irq_domain = irq_domain_add_linear(NULL, 1, &irq_domain_simple_ops, NULL);
+	if (!dock->tp_irq_domain)
+		return -ENOMEM;
+
+	dock->tp_irq = irq_create_mapping(dock->tp_irq_domain, 0);
+	if (!dock->tp_irq)
+		return -ENOMEM;
+
+	irq_set_chip_data(dock->tp_irq, dock);
+	irq_set_chip_and_handler(dock->tp_irq, &dock->tp_irqchip, handle_simple_irq);
+	irq_set_nested_thread(dock->tp_irq, true);
+	irq_set_noprobe(dock->tp_irq);
+
+	dev_info(dev, "Asus TF103C board-revision: %d\n", dock->board_rev);
+
+	tf103c_dock_start_hpd(dock);
+
+	device_init_wakeup(dev, true);
+	i2c_set_clientdata(client, dock);
+	return 0;
+}
+
+static int tf103c_dock_remove(struct i2c_client *client)
+{
+	struct tf103c_dock_data *dock = i2c_get_clientdata(client);
+
+	tf103c_dock_stop_hpd(dock);
+	tf103c_dock_disable(dock);
+
+	return 0;
+}
+
+static int __maybe_unused tf103c_dock_suspend(struct device *dev)
+{
+	struct tf103c_dock_data *dock = dev_get_drvdata(dev);
+
+	tf103c_dock_stop_hpd(dock);
+
+	if (dock->enabled) {
+		tf103c_dock_ec_cmd(dock, tf103c_dock_suspend_cmd);
+
+		if (device_may_wakeup(dev))
+			enable_irq_wake(dock->irq);
+	}
+
+	return 0;
+}
+
+static int __maybe_unused tf103c_dock_resume(struct device *dev)
+{
+	struct tf103c_dock_data *dock = dev_get_drvdata(dev);
+
+	if (dock->enabled) {
+		if (device_may_wakeup(dev))
+			disable_irq_wake(dock->irq);
+
+		/* Don't try to resume if the dock was unplugged during suspend */
+		if (gpiod_get_value(dock->hpd_gpio))
+			tf103c_dock_ec_cmd(dock, tf103c_dock_enable_cmd);
+	}
+
+	tf103c_dock_start_hpd(dock);
+	return 0;
+}
+
+SIMPLE_DEV_PM_OPS(tf103c_dock_pm_ops, tf103c_dock_suspend, tf103c_dock_resume);
+
+static const struct acpi_device_id tf103c_dock_acpi_match[] = {
+	{"NPCE69A"},
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, tf103c_dock_acpi_match);
+
+static struct i2c_driver tf103c_dock_driver = {
+	.driver = {
+		.name = "asus-tf103c-dock",
+		.pm = &tf103c_dock_pm_ops,
+		.acpi_match_table = tf103c_dock_acpi_match,
+	},
+	.probe_new = tf103c_dock_probe,
+	.remove	= tf103c_dock_remove,
+};
+module_i2c_driver(tf103c_dock_driver);
+
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com");
+MODULE_DESCRIPTION("X86 Android tablets DSDT fixups driver");
+MODULE_LICENSE("GPL");