1 files changed, 479 insertions, 61 deletions

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 95ee92a91bd2..dfc7309e3d38 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -14,6 +14,8 @@
  *
  */
 
+#include <linux/acpi.h>
+#include <linux/dmi.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/completion.h>
@@ -25,6 +27,7 @@
 #include <linux/interrupt.h>
 #include <linux/of.h>
 #include <linux/slab.h>
+#include <asm/unaligned.h>
 
 /* Version */
 #define MXT_VER_20		20
@@ -79,6 +82,7 @@
 #define MXT_SPT_DIGITIZER_T43		43
 #define MXT_SPT_MESSAGECOUNT_T44	44
 #define MXT_SPT_CTECONFIG_T46		46
+#define MXT_TOUCH_MULTITOUCHSCREEN_T100 100
 
 /* MXT_GEN_MESSAGE_T5 object */
 #define MXT_RPTID_NOMSG		0xff
@@ -185,6 +189,36 @@ struct t9_range {
 #define MXT_RESET_VALUE		0x01
 #define MXT_BACKUP_VALUE	0x55
 
+/* T100 Multiple Touch Touchscreen */
+#define MXT_T100_CTRL		0
+#define MXT_T100_CFG1		1
+#define MXT_T100_TCHAUX		3
+#define MXT_T100_XRANGE		13
+#define MXT_T100_YRANGE		24
+
+#define MXT_T100_CFG_SWITCHXY	BIT(5)
+
+#define MXT_T100_TCHAUX_VECT	BIT(0)
+#define MXT_T100_TCHAUX_AMPL	BIT(1)
+#define MXT_T100_TCHAUX_AREA	BIT(2)
+
+#define MXT_T100_DETECT		BIT(7)
+#define MXT_T100_TYPE_MASK	0x70
+
+enum t100_type {
+	MXT_T100_TYPE_FINGER		= 1,
+	MXT_T100_TYPE_PASSIVE_STYLUS	= 2,
+	MXT_T100_TYPE_HOVERING_FINGER	= 4,
+	MXT_T100_TYPE_GLOVE		= 5,
+	MXT_T100_TYPE_LARGE_TOUCH	= 6,
+};
+
+#define MXT_DISTANCE_ACTIVE_TOUCH	0
+#define MXT_DISTANCE_HOVERING		1
+
+#define MXT_TOUCH_MAJOR_DEFAULT		1
+#define MXT_PRESSURE_DEFAULT		1
+
 /* Delay times */
 #define MXT_BACKUP_TIME		50	/* msec */
 #define MXT_RESET_TIME		200	/* msec */
@@ -244,6 +278,9 @@ struct mxt_data {
 	unsigned int max_y;
 	bool in_bootloader;
 	u16 mem_size;
+	u8 t100_aux_ampl;
+	u8 t100_aux_area;
+	u8 t100_aux_vect;
 	u8 max_reportid;
 	u32 config_crc;
 	u32 info_crc;
@@ -253,6 +290,7 @@ struct mxt_data {
 	bool update_input;
 	u8 last_message_count;
 	u8 num_touchids;
+	u8 multitouch;
 
 	/* Cached parameters from object table */
 	u16 T5_address;
@@ -264,6 +302,8 @@ struct mxt_data {
 	u8 T9_reportid_max;
 	u8 T19_reportid;
 	u16 T44_address;
+	u8 T100_reportid_min;
+	u8 T100_reportid_max;
 
 	/* for fw update in bootloader */
 	struct completion bl_completion;
@@ -686,15 +726,15 @@ static void mxt_input_button(struct mxt_data *data, u8 *message)
 {
 	struct input_dev *input = data->input_dev;
 	const struct mxt_platform_data *pdata = data->pdata;
-	bool button;
 	int i;
 
-	/* Active-low switch */
 	for (i = 0; i < pdata->t19_num_keys; i++) {
 		if (pdata->t19_keymap[i] == KEY_RESERVED)
 			continue;
-		button = !(message[1] & (1 << i));
-		input_report_key(input, pdata->t19_keymap[i], button);
+
+		/* Active-low switch */
+		input_report_key(input, pdata->t19_keymap[i],
+				 !(message[1] & BIT(i)));
 	}
 }
 
@@ -771,6 +811,114 @@ static void mxt_proc_t9_message(struct mxt_data *data, u8 *message)
 	data->update_input = true;
 }
 
+static void mxt_proc_t100_message(struct mxt_data *data, u8 *message)
+{
+	struct device *dev = &data->client->dev;
+	struct input_dev *input_dev = data->input_dev;
+	int id;
+	u8 status;
+	u8 type = 0;
+	u16 x;
+	u16 y;
+	int distance = 0;
+	int tool = 0;
+	u8 major = 0;
+	u8 pressure = 0;
+	u8 orientation = 0;
+
+	id = message[0] - data->T100_reportid_min - 2;
+
+	/* ignore SCRSTATUS events */
+	if (id < 0)
+		return;
+
+	status = message[1];
+	x = get_unaligned_le16(&message[2]);
+	y = get_unaligned_le16(&message[4]);
+
+	if (status & MXT_T100_DETECT) {
+		type = (status & MXT_T100_TYPE_MASK) >> 4;
+
+		switch (type) {
+		case MXT_T100_TYPE_HOVERING_FINGER:
+			tool = MT_TOOL_FINGER;
+			distance = MXT_DISTANCE_HOVERING;
+
+			if (data->t100_aux_vect)
+				orientation = message[data->t100_aux_vect];
+
+			break;
+
+		case MXT_T100_TYPE_FINGER:
+		case MXT_T100_TYPE_GLOVE:
+			tool = MT_TOOL_FINGER;
+			distance = MXT_DISTANCE_ACTIVE_TOUCH;
+
+			if (data->t100_aux_area)
+				major = message[data->t100_aux_area];
+
+			if (data->t100_aux_ampl)
+				pressure = message[data->t100_aux_ampl];
+
+			if (data->t100_aux_vect)
+				orientation = message[data->t100_aux_vect];
+
+			break;
+
+		case MXT_T100_TYPE_PASSIVE_STYLUS:
+			tool = MT_TOOL_PEN;
+
+			/*
+			 * Passive stylus is reported with size zero so
+			 * hardcode.
+			 */
+			major = MXT_TOUCH_MAJOR_DEFAULT;
+
+			if (data->t100_aux_ampl)
+				pressure = message[data->t100_aux_ampl];
+
+			break;
+
+		case MXT_T100_TYPE_LARGE_TOUCH:
+			/* Ignore suppressed touch */
+			break;
+
+		default:
+			dev_dbg(dev, "Unexpected T100 type\n");
+			return;
+		}
+	}
+
+	/*
+	 * Values reported should be non-zero if tool is touching the
+	 * device
+	 */
+	if (!pressure && type != MXT_T100_TYPE_HOVERING_FINGER)
+		pressure = MXT_PRESSURE_DEFAULT;
+
+	input_mt_slot(input_dev, id);
+
+	if (status & MXT_T100_DETECT) {
+		dev_dbg(dev, "[%u] type:%u x:%u y:%u a:%02X p:%02X v:%02X\n",
+			id, type, x, y, major, pressure, orientation);
+
+		input_mt_report_slot_state(input_dev, tool, 1);
+		input_report_abs(input_dev, ABS_MT_POSITION_X, x);
+		input_report_abs(input_dev, ABS_MT_POSITION_Y, y);
+		input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR, major);
+		input_report_abs(input_dev, ABS_MT_PRESSURE, pressure);
+		input_report_abs(input_dev, ABS_MT_DISTANCE, distance);
+		input_report_abs(input_dev, ABS_MT_ORIENTATION, orientation);
+	} else {
+		dev_dbg(dev, "[%u] release\n", id);
+
+		/* close out slot */
+		input_mt_report_slot_state(input_dev, 0, 0);
+	}
+
+	data->update_input = true;
+}
+
 static int mxt_proc_message(struct mxt_data *data, u8 *message)
 {
 	u8 report_id = message[0];
@@ -786,9 +934,12 @@ static int mxt_proc_message(struct mxt_data *data, u8 *message)
 		 * is not yet registered.
 		 */
 		mxt_dump_message(data, message);
-	} else if (report_id >= data->T9_reportid_min
-	    && report_id <= data->T9_reportid_max) {
+	} else if (report_id >= data->T9_reportid_min &&
+		   report_id <= data->T9_reportid_max) {
 		mxt_proc_t9_message(data, message);
+	} else if (report_id >= data->T100_reportid_min &&
+		   report_id <= data->T100_reportid_max) {
+		mxt_proc_t100_message(data, message);
 	} else if (report_id == data->T19_reportid) {
 		mxt_input_button(data, message);
 		data->update_input = true;
@@ -1411,6 +1562,8 @@ static void mxt_free_object_table(struct mxt_data *data)
 	data->T9_reportid_max = 0;
 	data->T19_reportid = 0;
 	data->T44_address = 0;
+	data->T100_reportid_min = 0;
+	data->T100_reportid_max = 0;
 	data->max_reportid = 0;
 }
 
@@ -1487,6 +1640,7 @@ static int mxt_get_object_table(struct mxt_data *data)
 			data->T7_address = object->start_address;
 			break;
 		case MXT_TOUCH_MULTI_T9:
+			data->multitouch = MXT_TOUCH_MULTI_T9;
 			data->T9_reportid_min = min_id;
 			data->T9_reportid_max = max_id;
 			data->num_touchids = object->num_report_ids
@@ -1498,6 +1652,13 @@ static int mxt_get_object_table(struct mxt_data *data)
 		case MXT_SPT_GPIOPWM_T19:
 			data->T19_reportid = min_id;
 			break;
+		case MXT_TOUCH_MULTITOUCHSCREEN_T100:
+			data->multitouch = MXT_TOUCH_MULTITOUCHSCREEN_T100;
+			data->T100_reportid_min = min_id;
+			data->T100_reportid_max = max_id;
+			/* first two report IDs reserved */
+			data->num_touchids = object->num_report_ids - 2;
+			break;
 		}
 
 		end_address = object->start_address
@@ -1582,22 +1743,138 @@ static int mxt_read_t9_resolution(struct mxt_data *data)
 	return 0;
 }
 
+static int mxt_read_t100_config(struct mxt_data *data)
+{
+	struct i2c_client *client = data->client;
+	int error;
+	struct mxt_object *object;
+	u16 range_x, range_y;
+	u8 cfg, tchaux;
+	u8 aux;
+
+	object = mxt_get_object(data, MXT_TOUCH_MULTITOUCHSCREEN_T100);
+	if (!object)
+		return -EINVAL;
+
+	error = __mxt_read_reg(client,
+			       object->start_address + MXT_T100_XRANGE,
+			       sizeof(range_x), &range_x);
+	if (error)
+		return error;
+
+	le16_to_cpus(&range_x);
+
+	error = __mxt_read_reg(client,
+			       object->start_address + MXT_T100_YRANGE,
+			       sizeof(range_y), &range_y);
+	if (error)
+		return error;
+
+	le16_to_cpus(&range_y);
+
+	error =  __mxt_read_reg(client,
+				object->start_address + MXT_T100_CFG1,
+				1, &cfg);
+	if (error)
+		return error;
+
+	error =  __mxt_read_reg(client,
+				object->start_address + MXT_T100_TCHAUX,
+				1, &tchaux);
+	if (error)
+		return error;
+
+	/* Handle default values */
+	if (range_x == 0)
+		range_x = 1023;
+
+	if (range_y == 0)
+		range_y = 1023;
+
+	if (cfg & MXT_T100_CFG_SWITCHXY) {
+		data->max_x = range_y;
+		data->max_y = range_x;
+	} else {
+		data->max_x = range_x;
+		data->max_y = range_y;
+	}
+
+	/* allocate aux bytes */
+	aux = 6;
+
+	if (tchaux & MXT_T100_TCHAUX_VECT)
+		data->t100_aux_vect = aux++;
+
+	if (tchaux & MXT_T100_TCHAUX_AMPL)
+		data->t100_aux_ampl = aux++;
+
+	if (tchaux & MXT_T100_TCHAUX_AREA)
+		data->t100_aux_area = aux++;
+
+	dev_dbg(&client->dev,
+		"T100 aux mappings vect:%u ampl:%u area:%u\n",
+		data->t100_aux_vect, data->t100_aux_ampl, data->t100_aux_area);
+
+	dev_info(&client->dev,
+		 "T100 Touchscreen size X%uY%u\n", data->max_x, data->max_y);
+
+	return 0;
+}
+
 static int mxt_input_open(struct input_dev *dev);
 static void mxt_input_close(struct input_dev *dev);
 
-static int mxt_initialize_t9_input_device(struct mxt_data *data)
+static void mxt_set_up_as_touchpad(struct input_dev *input_dev,
+				   struct mxt_data *data)
 {
-	struct device *dev = &data->client->dev;
 	const struct mxt_platform_data *pdata = data->pdata;
+	int i;
+
+	input_dev->name = "Atmel maXTouch Touchpad";
+
+	__set_bit(INPUT_PROP_BUTTONPAD, input_dev->propbit);
+
+	input_abs_set_res(input_dev, ABS_X, MXT_PIXELS_PER_MM);
+	input_abs_set_res(input_dev, ABS_Y, MXT_PIXELS_PER_MM);
+	input_abs_set_res(input_dev, ABS_MT_POSITION_X,
+			  MXT_PIXELS_PER_MM);
+	input_abs_set_res(input_dev, ABS_MT_POSITION_Y,
+			  MXT_PIXELS_PER_MM);
+
+	for (i = 0; i < pdata->t19_num_keys; i++)
+		if (pdata->t19_keymap[i] != KEY_RESERVED)
+			input_set_capability(input_dev, EV_KEY,
+					     pdata->t19_keymap[i]);
+}
+
+static int mxt_initialize_input_device(struct mxt_data *data)
+{
+	const struct mxt_platform_data *pdata = data->pdata;
+	struct device *dev = &data->client->dev;
 	struct input_dev *input_dev;
 	int error;
 	unsigned int num_mt_slots;
 	unsigned int mt_flags = 0;
-	int i;
 
-	error = mxt_read_t9_resolution(data);
-	if (error)
-		dev_warn(dev, "Failed to initialize T9 resolution\n");
+	switch (data->multitouch) {
+	case MXT_TOUCH_MULTI_T9:
+		num_mt_slots = data->T9_reportid_max - data->T9_reportid_min + 1;
+		error = mxt_read_t9_resolution(data);
+		if (error)
+			dev_warn(dev, "Failed to initialize T9 resolution\n");
+		break;
+
+	case MXT_TOUCH_MULTITOUCHSCREEN_T100:
+		num_mt_slots = data->num_touchids;
+		error = mxt_read_t100_config(data);
+		if (error)
+			dev_warn(dev, "Failed to read T100 config\n");
+		break;
+
+	default:
+		dev_err(dev, "Invalid multitouch object\n");
+		return -EINVAL;
+	}
 
 	input_dev = input_allocate_device();
 	if (!input_dev) {
@@ -1612,54 +1889,76 @@ static int mxt_initialize_t9_input_device(struct mxt_data *data)
 	input_dev->open = mxt_input_open;
 	input_dev->close = mxt_input_close;
 
-	__set_bit(EV_ABS, input_dev->evbit);
-	__set_bit(EV_KEY, input_dev->evbit);
-	__set_bit(BTN_TOUCH, input_dev->keybit);
+	input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
 
-	if (pdata->t19_num_keys) {
-		__set_bit(INPUT_PROP_BUTTONPAD, input_dev->propbit);
+	/* For single touch */
+	input_set_abs_params(input_dev, ABS_X, 0, data->max_x, 0, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, data->max_y, 0, 0);
 
-		for (i = 0; i < pdata->t19_num_keys; i++)
-			if (pdata->t19_keymap[i] != KEY_RESERVED)
-				input_set_capability(input_dev, EV_KEY,
-						     pdata->t19_keymap[i]);
+	if (data->multitouch == MXT_TOUCH_MULTI_T9 ||
+	    (data->multitouch == MXT_TOUCH_MULTITOUCHSCREEN_T100 &&
+	     data->t100_aux_ampl)) {
+		input_set_abs_params(input_dev, ABS_PRESSURE, 0, 255, 0, 0);
+	}
 
+	/* If device has buttons we assume it is a touchpad */
+	if (pdata->t19_num_keys) {
+		mxt_set_up_as_touchpad(input_dev, data);
 		mt_flags |= INPUT_MT_POINTER;
-
-		input_abs_set_res(input_dev, ABS_X, MXT_PIXELS_PER_MM);
-		input_abs_set_res(input_dev, ABS_Y, MXT_PIXELS_PER_MM);
-		input_abs_set_res(input_dev, ABS_MT_POSITION_X,
-				  MXT_PIXELS_PER_MM);
-		input_abs_set_res(input_dev, ABS_MT_POSITION_Y,
-				  MXT_PIXELS_PER_MM);
-
-		input_dev->name = "Atmel maXTouch Touchpad";
 	}
 
-	/* For single touch */
-	input_set_abs_params(input_dev, ABS_X,
-			     0, data->max_x, 0, 0);
-	input_set_abs_params(input_dev, ABS_Y,
-			     0, data->max_y, 0, 0);
-	input_set_abs_params(input_dev, ABS_PRESSURE,
-			     0, 255, 0, 0);
-
 	/* For multi touch */
-	num_mt_slots = data->T9_reportid_max - data->T9_reportid_min + 1;
 	error = input_mt_init_slots(input_dev, num_mt_slots, mt_flags);
 	if (error) {
 		dev_err(dev, "Error %d initialising slots\n", error);
 		goto err_free_mem;
 	}
 
-	input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
-			     0, MXT_MAX_AREA, 0, 0);
+	if (data->multitouch == MXT_TOUCH_MULTITOUCHSCREEN_T100) {
+		input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE,
+				     0, MT_TOOL_MAX, 0, 0);
+		input_set_abs_params(input_dev, ABS_MT_DISTANCE,
+				     MXT_DISTANCE_ACTIVE_TOUCH,
+				     MXT_DISTANCE_HOVERING,
+				     0, 0);
+	}
+
 	input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 			     0, data->max_x, 0, 0);
 	input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
 			     0, data->max_y, 0, 0);
-	input_set_abs_params(input_dev, ABS_MT_PRESSURE,
-			     0, 255, 0, 0);
+
+	if (data->multitouch == MXT_TOUCH_MULTI_T9 ||
+	    (data->multitouch == MXT_TOUCH_MULTITOUCHSCREEN_T100 &&
+	     data->t100_aux_area)) {
+		input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
+				     0, MXT_MAX_AREA, 0, 0);
+	}
+
+	if (data->multitouch == MXT_TOUCH_MULTI_T9 ||
+	    (data->multitouch == MXT_TOUCH_MULTITOUCHSCREEN_T100 &&
+	     data->t100_aux_ampl)) {
+		input_set_abs_params(input_dev, ABS_MT_PRESSURE,
+				     0, 255, 0, 0);
+	}
+
+	if (data->multitouch == MXT_TOUCH_MULTITOUCHSCREEN_T100 &&
+	    data->t100_aux_vect) {
+		input_set_abs_params(input_dev, ABS_MT_ORIENTATION,
+				     0, 255, 0, 0);
+	}
+
+	if (data->multitouch == MXT_TOUCH_MULTITOUCHSCREEN_T100 &&
+	    data->t100_aux_ampl) {
+		input_set_abs_params(input_dev, ABS_MT_PRESSURE,
+				     0, 255, 0, 0);
+	}
+
+	if (data->multitouch == MXT_TOUCH_MULTITOUCHSCREEN_T100 &&
+	    data->t100_aux_vect) {
+		input_set_abs_params(input_dev, ABS_MT_ORIENTATION,
+				     0, 255, 0, 0);
+	}
 
 	input_set_drvdata(input_dev, data);
 
@@ -1765,9 +2064,13 @@ static int mxt_configure_objects(struct mxt_data *data,
 			dev_warn(dev, "Error %d updating config\n", error);
 	}
 
-	error = mxt_initialize_t9_input_device(data);
-	if (error)
-		return error;
+	if (data->multitouch) {
+		error = mxt_initialize_input_device(data);
+		if (error)
+			return error;
+	} else {
+		dev_warn(dev, "No touch object detected\n");
+	}
 
 	dev_info(dev,
 		 "Family: %u Variant: %u Firmware V%u.%u.%02X Objects: %u\n",
@@ -2044,15 +2347,13 @@ static const struct attribute_group mxt_attr_group = {
 static void mxt_start(struct mxt_data *data)
 {
 	/* Touch enable */
-	mxt_write_object(data,
-			MXT_TOUCH_MULTI_T9, MXT_TOUCH_CTRL, 0x83);
+	mxt_write_object(data, data->multitouch, MXT_TOUCH_CTRL, 0x83);
 }
 
 static void mxt_stop(struct mxt_data *data)
 {
 	/* Touch disable */
-	mxt_write_object(data,
-			MXT_TOUCH_MULTI_T9, MXT_TOUCH_CTRL, 0);
+	mxt_write_object(data, data->multitouch, MXT_TOUCH_CTRL, 0);
 }
 
 static int mxt_input_open(struct input_dev *dev)
@@ -2072,7 +2373,7 @@ static void mxt_input_close(struct input_dev *dev)
 }
 
 #ifdef CONFIG_OF
-static struct mxt_platform_data *mxt_parse_dt(struct i2c_client *client)
+static const struct mxt_platform_data *mxt_parse_dt(struct i2c_client *client)
 {
 	struct mxt_platform_data *pdata;
 	u32 *keymap;
@@ -2080,7 +2381,7 @@ static struct mxt_platform_data *mxt_parse_dt(struct i2c_client *client)
 	int proplen, i, ret;
 
 	if (!client->dev.of_node)
-		return ERR_PTR(-ENODEV);
+		return ERR_PTR(-ENOENT);
 
 	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
@@ -2111,25 +2412,132 @@ static struct mxt_platform_data *mxt_parse_dt(struct i2c_client *client)
 	return pdata;
 }
 #else
-static struct mxt_platform_data *mxt_parse_dt(struct i2c_client *client)
+static const struct mxt_platform_data *mxt_parse_dt(struct i2c_client *client)
 {
-	dev_dbg(&client->dev, "No platform data specified\n");
-	return ERR_PTR(-EINVAL);
+	return ERR_PTR(-ENOENT);
+}
+#endif
+
+#ifdef CONFIG_ACPI
+
+struct mxt_acpi_platform_data {
+	const char *hid;
+	struct mxt_platform_data pdata;
+};
+
+static unsigned int samus_touchpad_buttons[] = {
+	KEY_RESERVED,
+	KEY_RESERVED,
+	KEY_RESERVED,
+	BTN_LEFT
+};
+
+static struct mxt_acpi_platform_data samus_platform_data[] = {
+	{
+		/* Touchpad */
+		.hid	= "ATML0000",
+		.pdata	= {
+			.t19_num_keys	= ARRAY_SIZE(samus_touchpad_buttons),
+			.t19_keymap	= samus_touchpad_buttons,
+		},
+	},
+	{
+		/* Touchscreen */
+		.hid	= "ATML0001",
+	},
+	{ }
+};
+
+static const struct dmi_system_id mxt_dmi_table[] = {
+	{
+		/* 2015 Google Pixel */
+		.ident = "Chromebook Pixel 2",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Samus"),
+		},
+		.driver_data = samus_platform_data,
+	},
+	{ }
+};
+
+static const struct mxt_platform_data *mxt_parse_acpi(struct i2c_client *client)
+{
+	struct acpi_device *adev;
+	const struct dmi_system_id *system_id;
+	const struct mxt_acpi_platform_data *acpi_pdata;
+
+	/*
+	 * Ignore ACPI devices representing bootloader mode.
+	 *
+	 * This is a bit of a hack: Google Chromebook BIOS creates ACPI
+	 * devices for both application and bootloader modes, but we are
+	 * interested in application mode only (if device is in bootloader
+	 * mode we'll end up switching into application anyway). So far
+	 * application mode addresses were all above 0x40, so we'll use it
+	 * as a threshold.
+	 */
+	if (client->addr < 0x40)
+		return ERR_PTR(-ENXIO);
+
+	adev = ACPI_COMPANION(&client->dev);
+	if (!adev)
+		return ERR_PTR(-ENOENT);
+
+	system_id = dmi_first_match(mxt_dmi_table);
+	if (!system_id)
+		return ERR_PTR(-ENOENT);
+
+	acpi_pdata = system_id->driver_data;
+	if (!acpi_pdata)
+		return ERR_PTR(-ENOENT);
+
+	while (acpi_pdata->hid) {
+		if (!strcmp(acpi_device_hid(adev), acpi_pdata->hid))
+			return &acpi_pdata->pdata;
+
+		acpi_pdata++;
+	}
+
+	return ERR_PTR(-ENOENT);
+}
+#else
+static const struct mxt_platform_data *mxt_parse_acpi(struct i2c_client *client)
+{
+	return ERR_PTR(-ENOENT);
 }
 #endif
 
+static const struct mxt_platform_data *
+mxt_get_platform_data(struct i2c_client *client)
+{
+	const struct mxt_platform_data *pdata;
+
+	pdata = dev_get_platdata(&client->dev);
+	if (pdata)
+		return pdata;
+
+	pdata = mxt_parse_dt(client);
+	if (!IS_ERR(pdata) || PTR_ERR(pdata) != -ENOENT)
+		return pdata;
+
+	pdata = mxt_parse_acpi(client);
+	if (!IS_ERR(pdata) || PTR_ERR(pdata) != -ENOENT)
+		return pdata;
+
+	dev_err(&client->dev, "No platform data specified\n");
+	return ERR_PTR(-EINVAL);
+}
+
 static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	struct mxt_data *data;
 	const struct mxt_platform_data *pdata;
 	int error;
 
-	pdata = dev_get_platdata(&client->dev);
-	if (!pdata) {
-		pdata = mxt_parse_dt(client);
-		if (IS_ERR(pdata))
-			return PTR_ERR(pdata);
-	}
+	pdata = mxt_get_platform_data(client);
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
 
 	data = kzalloc(sizeof(struct mxt_data), GFP_KERNEL);
 	if (!data) {
@@ -2237,6 +2645,15 @@ static const struct of_device_id mxt_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, mxt_of_match);
 
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id mxt_acpi_id[] = {
+	{ "ATML0000", 0 },	/* Touchpad */
+	{ "ATML0001", 0 },	/* Touchscreen */
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, mxt_acpi_id);
+#endif
+
 static const struct i2c_device_id mxt_id[] = {
 	{ "qt602240_ts", 0 },
 	{ "atmel_mxt_ts", 0 },
@@ -2251,6 +2668,7 @@ static struct i2c_driver mxt_driver = {
 		.name	= "atmel_mxt_ts",
 		.owner	= THIS_MODULE,
 		.of_match_table = of_match_ptr(mxt_of_match),
+		.acpi_match_table = ACPI_PTR(mxt_acpi_id),
 		.pm	= &mxt_pm_ops,
 	},
 	.probe		= mxt_probe,