Input: exc3000 - add EXC80H60 and EXC80H84 support

This adds support for EXC80H60 and EXCH84 controllers, which
use a different event type id and have two extra bits for the
resolution (so the maximum is 16K instead of 4K).

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200805160520.456570-3-sebastian.reichel@collabora.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: sre

Documentation/devicetree/bindings/input/touchscreen/eeti,exc3000.yaml

@@ -14,7 +14,10 @@ allOf:
 
 properties:
   compatible:
-    const: eeti,exc3000
+    enum:
+      - eeti,exc3000
+      - eeti,exc80h60
+      - eeti,exc80h84
   reg:
     const: 0x2a
   interrupts:

drivers/input/touchscreen/exc3000.c

@@ -16,18 +16,51 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/sizes.h>
 #include <linux/timer.h>
 #include <asm/unaligned.h>
 
 #define EXC3000_NUM_SLOTS		10
 #define EXC3000_SLOTS_PER_FRAME		5
 #define EXC3000_LEN_FRAME		66
 #define EXC3000_LEN_POINT		10
-#define EXC3000_MT_EVENT		6
+
+#define EXC3000_MT1_EVENT		0x06
+#define EXC3000_MT2_EVENT		0x18
+
 #define EXC3000_TIMEOUT_MS		100
 
+static const struct i2c_device_id exc3000_id[];
+
+struct eeti_dev_info {
+	const char *name;
+	int max_xy;
+};
+
+enum eeti_dev_id {
+	EETI_EXC3000,
+	EETI_EXC80H60,
+	EETI_EXC80H84,
+};
+
+static struct eeti_dev_info exc3000_info[] = {
+	[EETI_EXC3000] = {
+		.name = "EETI EXC3000 Touch Screen",
+		.max_xy = SZ_4K - 1,
+	},
+	[EETI_EXC80H60] = {
+		.name = "EETI EXC80H60 Touch Screen",
+		.max_xy = SZ_16K - 1,
+	},
+	[EETI_EXC80H84] = {
+		.name = "EETI EXC80H84 Touch Screen",
+		.max_xy = SZ_16K - 1,
+	},
+};
+
 struct exc3000_data {
 	struct i2c_client *client;
+	const struct eeti_dev_info *info;
 	struct input_dev *input;
 	struct touchscreen_properties prop;
 	struct timer_list timer;
@@ -58,10 +91,15 @@ static void exc3000_timer(struct timer_list *t)
 	input_sync(data->input);
 }
 
-static int exc3000_read_frame(struct i2c_client *client, u8 *buf)
+static int exc3000_read_frame(struct exc3000_data *data, u8 *buf)
 {
+	struct i2c_client *client = data->client;
+	u8 expected_event = EXC3000_MT1_EVENT;
 	int ret;
 
+	if (data->info->max_xy == SZ_16K - 1)
+		expected_event = EXC3000_MT2_EVENT;
+
 	ret = i2c_master_send(client, "'", 2);
 	if (ret < 0)
 		return ret;
@@ -76,19 +114,21 @@ static int exc3000_read_frame(struct i2c_client *client, u8 *buf)
 	if (ret != EXC3000_LEN_FRAME)
 		return -EIO;
 
-	if (get_unaligned_le16(buf) != EXC3000_LEN_FRAME ||
-			buf[2] != EXC3000_MT_EVENT)
+	if (get_unaligned_le16(buf) != EXC3000_LEN_FRAME)
+		return -EINVAL;
+
+	if (buf[2] != expected_event)
 		return -EINVAL;
 
 	return 0;
 }
 
-static int exc3000_read_data(struct i2c_client *client,
+static int exc3000_read_data(struct exc3000_data *data,
 			     u8 *buf, int *n_slots)
 {
 	int error;
 
-	error = exc3000_read_frame(client, buf);
+	error = exc3000_read_frame(data, buf);
 	if (error)
 		return error;
 
@@ -98,7 +138,7 @@ static int exc3000_read_data(struct i2c_client *client,
 
 	if (*n_slots > EXC3000_SLOTS_PER_FRAME) {
 		/* Read 2nd frame to get the rest of the contacts. */
-		error = exc3000_read_frame(client, buf + EXC3000_LEN_FRAME);
+		error = exc3000_read_frame(data, buf + EXC3000_LEN_FRAME);
 		if (error)
 			return error;
 
@@ -118,7 +158,7 @@ static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
 	int slots, total_slots;
 	int error;
 
-	error = exc3000_read_data(data->client, buf, &total_slots);
+	error = exc3000_read_data(data, buf, &total_slots);
 	if (error) {
 		/* Schedule a timer to release "stuck" contacts */
 		mod_timer(&data->timer,
@@ -149,13 +189,19 @@ static int exc3000_probe(struct i2c_client *client)
 {
 	struct exc3000_data *data;
 	struct input_dev *input;
-	int error;
+	int error, max_xy;
 
 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
 	data->client = client;
+	data->info = device_get_match_data(&client->dev);
+	if (!data->info) {
+		enum eeti_dev_id eeti_dev_id =
+			i2c_match_id(exc3000_id, client)->driver_data;
+		data->info = &exc3000_info[eeti_dev_id];
+	}
 	timer_setup(&data->timer, exc3000_timer, 0);
 
 	input = devm_input_allocate_device(&client->dev);
@@ -164,11 +210,13 @@ static int exc3000_probe(struct i2c_client *client)
 
 	data->input = input;
 
-	input->name = "EETI EXC3000 Touch Screen";
+	input->name = data->info->name;
 	input->id.bustype = BUS_I2C;
 
-	input_set_abs_params(input, ABS_MT_POSITION_X, 0, 4095, 0, 0);
-	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 4095, 0, 0);
+	max_xy = data->info->max_xy;
+	input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
+	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);
+
 	touchscreen_parse_properties(input, true, &data->prop);
 
 	error = input_mt_init_slots(input, EXC3000_NUM_SLOTS,
@@ -190,14 +238,18 @@ static int exc3000_probe(struct i2c_client *client)
 }
 
 static const struct i2c_device_id exc3000_id[] = {
-	{ "exc3000", 0 },
+	{ "exc3000", EETI_EXC3000 },
+	{ "exc80h60", EETI_EXC80H60 },
+	{ "exc80h84", EETI_EXC80H84 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, exc3000_id);
 
 #ifdef CONFIG_OF
 static const struct of_device_id exc3000_of_match[] = {
-	{ .compatible = "eeti,exc3000" },
+	{ .compatible = "eeti,exc3000", .data = &exc3000_info[EETI_EXC3000] },
+	{ .compatible = "eeti,exc80h60", .data = &exc3000_info[EETI_EXC80H60] },
+	{ .compatible = "eeti,exc80h84", .data = &exc3000_info[EETI_EXC80H84] },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, exc3000_of_match);