--- /dev/null
+/*
+ * Driver for ELAN eKTF2127 i2c touchscreen controller
+ *
+ * For this driver the layout of the Chipone icn8318 i2c
+ * touchscreencontroller is used.
+ *
+ * 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.
+ *
+ * Author:
+ * Michel Verlaan <michel.verl@gmail.com>
+ * Siebren Vroegindeweij <siebren.vroegindeweij@hotmail.com>
+ *
+ * Original chipone_icn8318 driver:
+ * Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+
+/* Packet header defines (first byte of data send / received) */
+#define EKTF2127_NOISE 0x40
+#define EKTF2127_RESPONSE 0x52
+#define EKTF2127_REQUEST 0x53
+#define EKTF2127_HELLO 0x55
+#define EKTF2127_REPORT 0x5d
+#define EKTF2127_CALIB_DONE 0x66
+
+/* Register defines (second byte of data send / received) */
+#define EKTF2127_ENV_NOISY 0x41
+#define EKTF2127_HEIGHT 0x60
+#define EKTF2127_WIDTH 0x63
+
+/* 2 bytes header + 5 * 3 bytes coordinates + 3 bytes pressure info + footer */
+#define EKTF2127_TOUCH_REPORT_SIZE 21
+#define EKTF2127_MAX_TOUCHES 5
+
+struct ektf2127_ts {
+ struct i2c_client *client;
+ struct input_dev *input;
+ struct gpio_desc *power_gpios;
+ struct touchscreen_properties prop;
+};
+
+static void ektf2127_parse_coordinates(const u8* buf, unsigned int touch_count,
+ struct input_mt_pos *touches)
+{
+ int index = 0;
+ int i;
+
+ for (i = 0; i < touch_count; i++) {
+ index = 2 + i * 3;
+
+ touches[i].x = (buf[index] & 0x0f);
+ touches[i].x <<= 8;
+ touches[i].x |= buf[index + 2];
+
+ touches[i].y = (buf[index] & 0xf0);
+ touches[i].y <<= 4;
+ touches[i].y |= buf[index + 1];
+ }
+}
+
+static void ektf2127_report_event(struct ektf2127_ts *ts, const u8 *buf)
+{
+ struct input_mt_pos touches[EKTF2127_MAX_TOUCHES];
+ int slots[EKTF2127_MAX_TOUCHES];
+ unsigned int touch_count, i;
+
+ touch_count = buf[1] & 0x07;
+ if (touch_count > EKTF2127_MAX_TOUCHES) {
+ dev_err(&ts->client->dev,
+ "Too many touches %d > %d\n",
+ touch_count, EKTF2127_MAX_TOUCHES);
+ touch_count = EKTF2127_MAX_TOUCHES;
+ }
+
+ ektf2127_parse_coordinates(buf, touch_count, touches);
+ input_mt_assign_slots(ts->input, slots, touches,
+ touch_count, 0);
+
+ for (i = 0; i < touch_count; i++) {
+ input_mt_slot(ts->input, slots[i]);
+ input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
+ touchscreen_report_pos(ts->input, &ts->prop,
+ touches[i].x, touches[i].y, true);
+ }
+
+ input_mt_sync_frame(ts->input);
+ input_sync(ts->input);
+}
+
+static irqreturn_t ektf2127_irq(int irq, void *dev_id)
+{
+ struct ektf2127_ts *ts = dev_id;
+ struct device *dev = &ts->client->dev;
+ char buf[EKTF2127_TOUCH_REPORT_SIZE];
+ int ret;
+
+ ret = i2c_master_recv(ts->client, buf, EKTF2127_TOUCH_REPORT_SIZE);
+ if (ret != EKTF2127_TOUCH_REPORT_SIZE) {
+ dev_err(dev, "Error reading touch data: %d\n", ret);
+ goto out;
+ }
+
+ switch (buf[0]) {
+ case EKTF2127_REPORT:
+ ektf2127_report_event(ts, buf);
+ break;
+
+ case EKTF2127_NOISE:
+ if (buf[1] == EKTF2127_ENV_NOISY)
+ dev_dbg(dev, "Environment is electrically noisy\n");
+ break;
+
+ case EKTF2127_HELLO:
+ case EKTF2127_CALIB_DONE:
+ break;
+
+ default:
+ dev_err(dev, "Unexpected packet header byte %#02x\n", buf[0]);
+ break;
+ }
+
+out:
+ return IRQ_HANDLED;
+}
+
+static int ektf2127_start(struct input_dev *dev)
+{
+ struct ektf2127_ts *ts = input_get_drvdata(dev);
+
+ enable_irq(ts->client->irq);
+ gpiod_set_value_cansleep(ts->power_gpios, 1);
+
+ return 0;
+}
+
+static void ektf2127_stop(struct input_dev *dev)
+{
+ struct ektf2127_ts *ts = input_get_drvdata(dev);
+
+ disable_irq(ts->client->irq);
+ gpiod_set_value_cansleep(ts->power_gpios, 0);
+}
+
+static int ektf2127_suspend(struct device *dev)
+{
+ struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev));
+
+ mutex_lock(&ts->input->mutex);
+ if (ts->input->users)
+ ektf2127_stop(ts->input);
+ mutex_unlock(&ts->input->mutex);
+
+ return 0;
+}
+
+static int ektf2127_resume(struct device *dev)
+{
+ struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev));
+
+ mutex_lock(&ts->input->mutex);
+ if (ts->input->users)
+ ektf2127_start(ts->input);
+ mutex_unlock(&ts->input->mutex);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(ektf2127_pm_ops, ektf2127_suspend,
+ ektf2127_resume);
+
+static int ektf2127_query_dimension(struct i2c_client *client, bool width)
+{
+ struct device *dev = &client->dev;
+ const char *what = width ? "width" : "height";
+ u8 what_code = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT;
+ u8 buf[4];
+ int ret;
+ int error;
+
+ /* Request dimension */
+ buf[0] = EKTF2127_REQUEST;
+ buf[1] = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT;
+ buf[2] = 0x00;
+ buf[3] = 0x00;
+ ret = i2c_master_send(client, buf, sizeof(buf));
+ if (ret != sizeof(buf)) {
+ error = ret < 0 ? ret : -EIO;
+ dev_err(dev, "Failed to request %s: %d\n", what, error);
+ return error;
+ }
+
+ msleep(20);
+
+ /* Read response */
+ ret = i2c_master_recv(client, buf, sizeof(buf));
+ if (ret != sizeof(buf)) {
+ error = ret < 0 ? ret : -EIO;
+ dev_err(dev, "Failed to receive %s data: %d\n", what, error);
+ return error;
+ }
+
+ if (buf[0] != EKTF2127_RESPONSE || buf[1] != what_code) {
+ dev_err(dev, "Unexpected %s data: %#02x %#02x\n",
+ what, buf[0], buf[1]);
+ return -EIO;
+ }
+
+ return (((buf[3] & 0xf0) << 4) | buf[2]) - 1;
+}
+
+static int ektf2127_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct ektf2127_ts *ts;
+ struct input_dev *input;
+ u8 buf[4];
+ int max_x, max_y;
+ int error;
+
+ if (!client->irq) {
+ dev_err(dev, "Error no irq specified\n");
+ return -EINVAL;
+ }
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ /* This requests the gpio *and* turns on the touchscreen controller */
+ ts->power_gpios = devm_gpiod_get(dev, "power", GPIOD_OUT_HIGH);
+ if (IS_ERR(ts->power_gpios)) {
+ error = PTR_ERR(ts->power_gpios);
+ if (error != -EPROBE_DEFER)
+ dev_err(dev, "Error getting power gpio: %d\n", error);
+ return error;
+ }
+
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ input->name = client->name;
+ input->id.bustype = BUS_I2C;
+ input->open = ektf2127_start;
+ input->close = ektf2127_stop;
+
+ ts->client = client;
+
+ /* Read hello (ignore result, depends on initial power state) */
+ msleep(20);
+ i2c_master_recv(ts->client, buf, sizeof(buf));
+
+ /* Read resolution from chip */
+ max_x = ektf2127_query_dimension(client, true);
+ if (max_x < 0)
+ return max_x;
+
+ max_y = ektf2127_query_dimension(client, false);
+ if (max_y < 0)
+ return max_y;
+
+ input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
+ input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
+ touchscreen_parse_properties(input, true, &ts->prop);
+
+ error = input_mt_init_slots(input, EKTF2127_MAX_TOUCHES,
+ INPUT_MT_DIRECT |
+ INPUT_MT_DROP_UNUSED |
+ INPUT_MT_TRACK);
+ if (error)
+ return error;
+
+ ts->input = input;
+ input_set_drvdata(input, ts);
+
+ error = devm_request_threaded_irq(dev, client->irq,
+ NULL, ektf2127_irq,
+ IRQF_ONESHOT, client->name, ts);
+ if (error) {
+ dev_err(dev, "Error requesting irq: %d\n", error);
+ return error;
+ }
+
+ /* Stop device till opened */
+ ektf2127_stop(ts->input);
+
+ error = input_register_device(input);
+ if (error)
+ return error;
+
+ i2c_set_clientdata(client, ts);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id ektf2127_of_match[] = {
+ { .compatible = "elan,ektf2127" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, ektf2127_of_match);
+#endif
+
+static const struct i2c_device_id ektf2127_i2c_id[] = {
+ { "ektf2127", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id);
+
+static struct i2c_driver ektf2127_driver = {
+ .driver = {
+ .name = "elan_ektf2127",
+ .pm = &ektf2127_pm_ops,
+ .of_match_table = of_match_ptr(ektf2127_of_match),
+ },
+ .probe = ektf2127_probe,
+ .id_table = ektf2127_i2c_id,
+};
+module_i2c_driver(ektf2127_driver);
+
+MODULE_DESCRIPTION("ELAN eKTF2127 I2C Touchscreen Driver");
+MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij");
+MODULE_LICENSE("GPL");
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff