1 files changed, 434 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/exc3000.c b/drivers/input/touchscreen/exc3000.c
new file mode 100644
index 000000000..a6597f026
--- /dev/null
+++ b/drivers/input/touchscreen/exc3000.c
@@ -0,0 +1,434 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for I2C connected EETI EXC3000 multiple touch controller
+ *
+ * Copyright (C) 2017 Ahmet Inan <inan@distec.de>
+ *
+ * minimal implementation based on egalax_ts.c and egalax_i2c.c
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#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_LEN_MODEL_NAME		16
+#define EXC3000_LEN_FW_VERSION		16
+
+#define EXC3000_MT1_EVENT		0x06
+#define EXC3000_MT2_EVENT		0x18
+
+#define EXC3000_TIMEOUT_MS		100
+
+#define EXC3000_RESET_MS		10
+#define EXC3000_READY_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 gpio_desc *reset;
+	struct timer_list timer;
+	u8 buf[2 * EXC3000_LEN_FRAME];
+	struct completion wait_event;
+	struct mutex query_lock;
+	int query_result;
+	char model[EXC3000_LEN_MODEL_NAME];
+	char fw_version[EXC3000_LEN_FW_VERSION];
+};
+
+static void exc3000_report_slots(struct input_dev *input,
+				 struct touchscreen_properties *prop,
+				 const u8 *buf, int num)
+{
+	for (; num--; buf += EXC3000_LEN_POINT) {
+		if (buf[0] & BIT(0)) {
+			input_mt_slot(input, buf[1]);
+			input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+			touchscreen_report_pos(input, prop,
+					       get_unaligned_le16(buf + 2),
+					       get_unaligned_le16(buf + 4),
+					       true);
+		}
+	}
+}
+
+static void exc3000_timer(struct timer_list *t)
+{
+	struct exc3000_data *data = from_timer(data, t, timer);
+
+	input_mt_sync_frame(data->input);
+	input_sync(data->input);
+}
+
+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;
+
+	if (ret != 2)
+		return -EIO;
+
+	ret = i2c_master_recv(client, buf, EXC3000_LEN_FRAME);
+	if (ret < 0)
+		return ret;
+
+	if (ret != EXC3000_LEN_FRAME)
+		return -EIO;
+
+	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 exc3000_data *data,
+			     u8 *buf, int *n_slots)
+{
+	int error;
+
+	error = exc3000_read_frame(data, buf);
+	if (error)
+		return error;
+
+	*n_slots = buf[3];
+	if (!*n_slots || *n_slots > EXC3000_NUM_SLOTS)
+		return -EINVAL;
+
+	if (*n_slots > EXC3000_SLOTS_PER_FRAME) {
+		/* Read 2nd frame to get the rest of the contacts. */
+		error = exc3000_read_frame(data, buf + EXC3000_LEN_FRAME);
+		if (error)
+			return error;
+
+		/* 2nd chunk must have number of contacts set to 0. */
+		if (buf[EXC3000_LEN_FRAME + 3] != 0)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int exc3000_query_interrupt(struct exc3000_data *data)
+{
+	u8 *buf = data->buf;
+	int error;
+
+	error = i2c_master_recv(data->client, buf, EXC3000_LEN_FRAME);
+	if (error < 0)
+		return error;
+
+	if (buf[0] != 'B')
+		return -EPROTO;
+
+	if (buf[4] == 'E')
+		strlcpy(data->model, buf + 5, sizeof(data->model));
+	else if (buf[4] == 'D')
+		strlcpy(data->fw_version, buf + 5, sizeof(data->fw_version));
+	else
+		return -EPROTO;
+
+	return 0;
+}
+
+static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
+{
+	struct exc3000_data *data = dev_id;
+	struct input_dev *input = data->input;
+	u8 *buf = data->buf;
+	int slots, total_slots;
+	int error;
+
+	if (mutex_is_locked(&data->query_lock)) {
+		data->query_result = exc3000_query_interrupt(data);
+		complete(&data->wait_event);
+		goto out;
+	}
+
+	error = exc3000_read_data(data, buf, &total_slots);
+	if (error) {
+		/* Schedule a timer to release "stuck" contacts */
+		mod_timer(&data->timer,
+			  jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS));
+		goto out;
+	}
+
+	/*
+	 * We read full state successfully, no contacts will be "stuck".
+	 */
+	del_timer_sync(&data->timer);
+
+	while (total_slots > 0) {
+		slots = min(total_slots, EXC3000_SLOTS_PER_FRAME);
+		exc3000_report_slots(input, &data->prop, buf + 4, slots);
+		total_slots -= slots;
+		buf += EXC3000_LEN_FRAME;
+	}
+
+	input_mt_sync_frame(input);
+	input_sync(input);
+
+out:
+	return IRQ_HANDLED;
+}
+
+static ssize_t fw_version_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct exc3000_data *data = i2c_get_clientdata(client);
+	static const u8 request[68] = {
+		0x67, 0x00, 0x42, 0x00, 0x03, 0x01, 'D', 0x00
+	};
+	int error;
+
+	mutex_lock(&data->query_lock);
+
+	data->query_result = -ETIMEDOUT;
+	reinit_completion(&data->wait_event);
+
+	error = i2c_master_send(client, request, sizeof(request));
+	if (error < 0) {
+		mutex_unlock(&data->query_lock);
+		return error;
+	}
+
+	wait_for_completion_interruptible_timeout(&data->wait_event, 1 * HZ);
+	mutex_unlock(&data->query_lock);
+
+	if (data->query_result < 0)
+		return data->query_result;
+
+	return sprintf(buf, "%s\n", data->fw_version);
+}
+static DEVICE_ATTR_RO(fw_version);
+
+static ssize_t exc3000_get_model(struct exc3000_data *data)
+{
+	static const u8 request[68] = {
+		0x67, 0x00, 0x42, 0x00, 0x03, 0x01, 'E', 0x00
+	};
+	struct i2c_client *client = data->client;
+	int error;
+
+	mutex_lock(&data->query_lock);
+	data->query_result = -ETIMEDOUT;
+	reinit_completion(&data->wait_event);
+
+	error = i2c_master_send(client, request, sizeof(request));
+	if (error < 0) {
+		mutex_unlock(&data->query_lock);
+		return error;
+	}
+
+	wait_for_completion_interruptible_timeout(&data->wait_event, 1 * HZ);
+	mutex_unlock(&data->query_lock);
+
+	return data->query_result;
+}
+
+static ssize_t model_show(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct exc3000_data *data = i2c_get_clientdata(client);
+	int error;
+
+	error = exc3000_get_model(data);
+	if (error < 0)
+		return error;
+
+	return sprintf(buf, "%s\n", data->model);
+}
+static DEVICE_ATTR_RO(model);
+
+static struct attribute *sysfs_attrs[] = {
+	&dev_attr_fw_version.attr,
+	&dev_attr_model.attr,
+	NULL
+};
+
+static struct attribute_group exc3000_attribute_group = {
+	.attrs = sysfs_attrs
+};
+
+static int exc3000_probe(struct i2c_client *client)
+{
+	struct exc3000_data *data;
+	struct input_dev *input;
+	int error, max_xy, retry;
+
+	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);
+	init_completion(&data->wait_event);
+	mutex_init(&data->query_lock);
+
+	data->reset = devm_gpiod_get_optional(&client->dev, "reset",
+					      GPIOD_OUT_HIGH);
+	if (IS_ERR(data->reset))
+		return PTR_ERR(data->reset);
+
+	if (data->reset) {
+		msleep(EXC3000_RESET_MS);
+		gpiod_set_value_cansleep(data->reset, 0);
+		msleep(EXC3000_READY_MS);
+	}
+
+	input = devm_input_allocate_device(&client->dev);
+	if (!input)
+		return -ENOMEM;
+
+	data->input = input;
+	input_set_drvdata(input, data);
+
+	input->name = data->info->name;
+	input->id.bustype = BUS_I2C;
+
+	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,
+				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+	if (error)
+		return error;
+
+	error = input_register_device(input);
+	if (error)
+		return error;
+
+	error = devm_request_threaded_irq(&client->dev, client->irq,
+					  NULL, exc3000_interrupt, IRQF_ONESHOT,
+					  client->name, data);
+	if (error)
+		return error;
+
+	/*
+	 * I²C does not have built-in recovery, so retry on failure. This
+	 * ensures, that the device probe will not fail for temporary issues
+	 * on the bus.  This is not needed for the sysfs calls (userspace
+	 * will receive the error code and can start another query) and
+	 * cannot be done for touch events (but that only means loosing one
+	 * or two touch events anyways).
+	 */
+	for (retry = 0; retry < 3; retry++) {
+		error = exc3000_get_model(data);
+		if (!error)
+			break;
+		dev_warn(&client->dev, "Retry %d get EETI EXC3000 model: %d\n",
+			 retry + 1, error);
+	}
+
+	if (error)
+		return error;
+
+	dev_dbg(&client->dev, "TS Model: %s", data->model);
+
+	i2c_set_clientdata(client, data);
+
+	error = devm_device_add_group(&client->dev, &exc3000_attribute_group);
+	if (error)
+		return error;
+
+	return 0;
+}
+
+static const struct i2c_device_id exc3000_id[] = {
+	{ "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", .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);
+#endif
+
+static struct i2c_driver exc3000_driver = {
+	.driver = {
+		.name	= "exc3000",
+		.of_match_table = of_match_ptr(exc3000_of_match),
+	},
+	.id_table	= exc3000_id,
+	.probe_new	= exc3000_probe,
+};
+
+module_i2c_driver(exc3000_driver);
+
+MODULE_AUTHOR("Ahmet Inan <inan@distec.de>");
+MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver");
+MODULE_LICENSE("GPL v2");