--- /dev/null
+/*
+ * Copyright (C) 2016, Jelle van der Waa <jelle@vdwaa.nl>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/delay.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/regulator/consumer.h>
+#include <asm/unaligned.h>
+
+#define ZET6223_MAX_FINGERS 16
+#define ZET6223_MAX_PKT_SIZE (3 + 4 * ZET6223_MAX_FINGERS)
+
+#define ZET6223_CMD_INFO 0xB2
+#define ZET6223_CMD_INFO_LENGTH 17
+#define ZET6223_VALID_PACKET 0x3c
+
+#define ZET6223_POWER_ON_DELAY_MSEC 30
+
+struct zet6223_ts {
+ struct i2c_client *client;
+ struct input_dev *input;
+ struct regulator *vcc;
+ struct regulator *vio;
+ struct touchscreen_properties prop;
+ struct regulator_bulk_data supplies[2];
+ u16 max_x;
+ u16 max_y;
+ u8 fingernum;
+};
+
+static int zet6223_start(struct input_dev *dev)
+{
+ struct zet6223_ts *ts = input_get_drvdata(dev);
+
+ enable_irq(ts->client->irq);
+
+ return 0;
+}
+
+static void zet6223_stop(struct input_dev *dev)
+{
+ struct zet6223_ts *ts = input_get_drvdata(dev);
+
+ disable_irq(ts->client->irq);
+}
+
+static irqreturn_t zet6223_irq(int irq, void *dev_id)
+{
+ struct zet6223_ts *ts = dev_id;
+ u16 finger_bits;
+
+ /*
+ * First 3 bytes are an identifier, two bytes of finger data.
+ * X, Y data per finger is 4 bytes.
+ */
+ u8 bufsize = 3 + 4 * ts->fingernum;
+ u8 buf[ZET6223_MAX_PKT_SIZE];
+ int i;
+ int ret;
+ int error;
+
+ ret = i2c_master_recv(ts->client, buf, bufsize);
+ if (ret != bufsize) {
+ error = ret < 0 ? ret : -EIO;
+ dev_err_ratelimited(&ts->client->dev,
+ "Error reading input data: %d\n", error);
+ return IRQ_HANDLED;
+ }
+
+ if (buf[0] != ZET6223_VALID_PACKET)
+ return IRQ_HANDLED;
+
+ finger_bits = get_unaligned_be16(buf + 1);
+ for (i = 0; i < ts->fingernum; i++) {
+ if (!(finger_bits & BIT(15 - i)))
+ continue;
+
+ input_mt_slot(ts->input, i);
+ input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
+ input_event(ts->input, EV_ABS, ABS_MT_POSITION_X,
+ ((buf[i + 3] >> 4) << 8) + buf[i + 4]);
+ input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y,
+ ((buf[i + 3] & 0xF) << 8) + buf[i + 5]);
+ }
+
+ input_mt_sync_frame(ts->input);
+ input_sync(ts->input);
+
+ return IRQ_HANDLED;
+}
+
+static void zet6223_power_off(void *_ts)
+{
+ struct zet6223_ts *ts = _ts;
+
+ regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
+}
+
+static int zet6223_power_on(struct zet6223_ts *ts)
+{
+ struct device *dev = &ts->client->dev;
+ int error;
+
+ ts->supplies[0].supply = "vio";
+ ts->supplies[1].supply = "vcc";
+
+ error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies),
+ ts->supplies);
+ if (error)
+ return error;
+
+ error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
+ if (error)
+ return error;
+
+ msleep(ZET6223_POWER_ON_DELAY_MSEC);
+
+ error = devm_add_action_or_reset(dev, zet6223_power_off, ts);
+ if (error) {
+ dev_err(dev, "failed to install poweroff action: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static int zet6223_query_device(struct zet6223_ts *ts)
+{
+ u8 buf[ZET6223_CMD_INFO_LENGTH];
+ u8 cmd = ZET6223_CMD_INFO;
+ int ret;
+ int error;
+
+ ret = i2c_master_send(ts->client, &cmd, sizeof(cmd));
+ if (ret != sizeof(cmd)) {
+ error = ret < 0 ? ret : -EIO;
+ dev_err(&ts->client->dev,
+ "touchpanel info cmd failed: %d\n", error);
+ return error;
+ }
+
+ ret = i2c_master_recv(ts->client, buf, sizeof(buf));
+ if (ret != sizeof(buf)) {
+ error = ret < 0 ? ret : -EIO;
+ dev_err(&ts->client->dev,
+ "failed to retrieve touchpanel info: %d\n", error);
+ return error;
+ }
+
+ ts->fingernum = buf[15] & 0x7F;
+ if (ts->fingernum > ZET6223_MAX_FINGERS) {
+ dev_warn(&ts->client->dev,
+ "touchpanel reports %d fingers, limiting to %d\n",
+ ts->fingernum, ZET6223_MAX_FINGERS);
+ ts->fingernum = ZET6223_MAX_FINGERS;
+ }
+
+ ts->max_x = get_unaligned_le16(&buf[8]);
+ ts->max_y = get_unaligned_le16(&buf[10]);
+
+ return 0;
+}
+
+static int zet6223_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct zet6223_ts *ts;
+ struct input_dev *input;
+ int error;
+
+ if (!client->irq) {
+ dev_err(dev, "no irq specified\n");
+ return -EINVAL;
+ }
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ ts->client = client;
+
+ error = zet6223_power_on(ts);
+ if (error)
+ return error;
+
+ error = zet6223_query_device(ts);
+ if (error)
+ return error;
+
+ ts->input = input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ input_set_drvdata(input, ts);
+
+ input->name = client->name;
+ input->id.bustype = BUS_I2C;
+ input->open = zet6223_start;
+ input->close = zet6223_stop;
+
+ input_set_abs_params(input, ABS_MT_POSITION_X, 0, ts->max_x, 0, 0);
+ input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ts->max_y, 0, 0);
+
+ touchscreen_parse_properties(input, true, &ts->prop);
+
+ error = input_mt_init_slots(input, ts->fingernum,
+ INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+ if (error)
+ return error;
+
+ error = devm_request_threaded_irq(dev, client->irq, NULL, zet6223_irq,
+ IRQF_ONESHOT, client->name, ts);
+ if (error) {
+ dev_err(dev, "failed to request irq %d: %d\n",
+ client->irq, error);
+ return error;
+ }
+
+ zet6223_stop(input);
+
+ error = input_register_device(input);
+ if (error)
+ return error;
+
+ return 0;
+}
+
+static const struct of_device_id zet6223_of_match[] = {
+ { .compatible = "zeitec,zet6223" },
+ { }
+};
+
+static const struct i2c_device_id zet6223_id[] = {
+ { "zet6223", 0},
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, zet6223_id);
+
+static struct i2c_driver zet6223_driver = {
+ .driver = {
+ .name = "zet6223",
+ .of_match_table = zet6223_of_match,
+ },
+ .probe = zet6223_probe,
+ .id_table = zet6223_id
+};
+module_i2c_driver(zet6223_driver);
+
+MODULE_AUTHOR("Jelle van der Waa <jelle@vdwaa.nl>");
+MODULE_DESCRIPTION("ZEITEC zet622x I2C touchscreen driver");
+MODULE_LICENSE("GPL");
projects / linux.git / commitdiff