--- /dev/null
+/*
+ * Driver for Goodix Touchscreens
+ *
+ * Copyright (c) 2014 Red Hat Inc.
+ *
+ * This code is based on gt9xx.c authored by andrew@goodix.com:
+ *
+ * 2010 - 2012 Goodix Technology.
+ */
+
+/*
+ * 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; version 2 of the License.
+ */
+
+#include <linux/kernel.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <asm/unaligned.h>
+
+struct goodix_ts_data {
+ struct i2c_client *client;
+ struct input_dev *input_dev;
+ int abs_x_max;
+ int abs_y_max;
+ unsigned int max_touch_num;
+ unsigned int int_trigger_type;
+};
+
+#define GOODIX_MAX_HEIGHT 4096
+#define GOODIX_MAX_WIDTH 4096
+#define GOODIX_INT_TRIGGER 1
+#define GOODIX_CONTACT_SIZE 8
+#define GOODIX_MAX_CONTACTS 10
+
+#define GOODIX_CONFIG_MAX_LENGTH 240
+
+/* Register defines */
+#define GOODIX_READ_COOR_ADDR 0x814E
+#define GOODIX_REG_CONFIG_DATA 0x8047
+#define GOODIX_REG_VERSION 0x8140
+
+#define RESOLUTION_LOC 1
+#define TRIGGER_LOC 6
+
+static const unsigned long goodix_irq_flags[] = {
+ IRQ_TYPE_EDGE_RISING,
+ IRQ_TYPE_EDGE_FALLING,
+ IRQ_TYPE_LEVEL_LOW,
+ IRQ_TYPE_LEVEL_HIGH,
+};
+
+/**
+ * goodix_i2c_read - read data from a register of the i2c slave device.
+ *
+ * @client: i2c device.
+ * @reg: the register to read from.
+ * @buf: raw write data buffer.
+ * @len: length of the buffer to write
+ */
+static int goodix_i2c_read(struct i2c_client *client,
+ u16 reg, u8 *buf, int len)
+{
+ struct i2c_msg msgs[2];
+ u16 wbuf = cpu_to_be16(reg);
+ int ret;
+
+ msgs[0].flags = 0;
+ msgs[0].addr = client->addr;
+ msgs[0].len = 2;
+ msgs[0].buf = (u8 *) &wbuf;
+
+ msgs[1].flags = I2C_M_RD;
+ msgs[1].addr = client->addr;
+ msgs[1].len = len;
+ msgs[1].buf = buf;
+
+ ret = i2c_transfer(client->adapter, msgs, 2);
+ return ret < 0 ? ret : (ret != ARRAY_SIZE(msgs) ? -EIO : 0);
+}
+
+static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
+{
+ int touch_num;
+ int error;
+
+ error = goodix_i2c_read(ts->client, GOODIX_READ_COOR_ADDR, data,
+ GOODIX_CONTACT_SIZE + 1);
+ if (error) {
+ dev_err(&ts->client->dev, "I2C transfer error: %d\n", error);
+ return error;
+ }
+
+ touch_num = data[0] & 0x0f;
+ if (touch_num > GOODIX_MAX_CONTACTS)
+ return -EPROTO;
+
+ if (touch_num > 1) {
+ data += 1 + GOODIX_CONTACT_SIZE;
+ error = goodix_i2c_read(ts->client,
+ GOODIX_READ_COOR_ADDR +
+ 1 + GOODIX_CONTACT_SIZE,
+ data,
+ GOODIX_CONTACT_SIZE * (touch_num - 1));
+ if (error)
+ return error;
+ }
+
+ return touch_num;
+}
+
+static void goodix_ts_report_touch(struct goodix_ts_data *ts, u8 *coor_data)
+{
+ int id = coor_data[0] & 0x0F;
+ int input_x = get_unaligned_le16(&coor_data[1]);
+ int input_y = get_unaligned_le16(&coor_data[3]);
+ int input_w = get_unaligned_le16(&coor_data[5]);
+
+ input_mt_slot(ts->input_dev, id);
+ input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, true);
+ input_report_abs(ts->input_dev, ABS_MT_POSITION_X, input_x);
+ input_report_abs(ts->input_dev, ABS_MT_POSITION_Y, input_y);
+ input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR, input_w);
+ input_report_abs(ts->input_dev, ABS_MT_WIDTH_MAJOR, input_w);
+}
+
+/**
+ * goodix_process_events - Process incoming events
+ *
+ * @ts: our goodix_ts_data pointer
+ *
+ * Called when the IRQ is triggered. Read the current device state, and push
+ * the input events to the user space.
+ */
+static void goodix_process_events(struct goodix_ts_data *ts)
+{
+ u8 point_data[1 + GOODIX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
+ int touch_num;
+ int i;
+
+ touch_num = goodix_ts_read_input_report(ts, point_data);
+ if (touch_num < 0)
+ return;
+
+ for (i = 0; i < touch_num; i++)
+ goodix_ts_report_touch(ts,
+ &point_data[1 + GOODIX_CONTACT_SIZE * i]);
+
+ input_mt_sync_frame(ts->input_dev);
+ input_sync(ts->input_dev);
+}
+
+/**
+ * goodix_ts_irq_handler - The IRQ handler
+ *
+ * @irq: interrupt number.
+ * @dev_id: private data pointer.
+ */
+static irqreturn_t goodix_ts_irq_handler(int irq, void *dev_id)
+{
+ static const u8 end_cmd[] = {
+ GOODIX_READ_COOR_ADDR >> 8,
+ GOODIX_READ_COOR_ADDR & 0xff,
+ 0
+ };
+ struct goodix_ts_data *ts = dev_id;
+
+ goodix_process_events(ts);
+
+ if (i2c_master_send(ts->client, end_cmd, sizeof(end_cmd)) < 0)
+ dev_err(&ts->client->dev, "I2C write end_cmd error\n");
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * goodix_read_config - Read the embedded configuration of the panel
+ *
+ * @ts: our goodix_ts_data pointer
+ *
+ * Must be called during probe
+ */
+static void goodix_read_config(struct goodix_ts_data *ts)
+{
+ u8 config[GOODIX_CONFIG_MAX_LENGTH];
+ int error;
+
+ error = goodix_i2c_read(ts->client, GOODIX_REG_CONFIG_DATA,
+ config,
+ GOODIX_CONFIG_MAX_LENGTH);
+ if (error) {
+ dev_warn(&ts->client->dev,
+ "Error reading config (%d), using defaults\n",
+ error);
+ ts->abs_x_max = GOODIX_MAX_WIDTH;
+ ts->abs_y_max = GOODIX_MAX_HEIGHT;
+ ts->int_trigger_type = GOODIX_INT_TRIGGER;
+ return;
+ }
+
+ ts->abs_x_max = get_unaligned_le16(&config[RESOLUTION_LOC]);
+ ts->abs_y_max = get_unaligned_le16(&config[RESOLUTION_LOC + 2]);
+ ts->int_trigger_type = (config[TRIGGER_LOC]) & 0x03;
+ if (!ts->abs_x_max || !ts->abs_y_max) {
+ dev_err(&ts->client->dev,
+ "Invalid config, using defaults\n");
+ ts->abs_x_max = GOODIX_MAX_WIDTH;
+ ts->abs_y_max = GOODIX_MAX_HEIGHT;
+ }
+}
+
+
+/**
+ * goodix_read_version - Read goodix touchscreen version
+ *
+ * @client: the i2c client
+ * @version: output buffer containing the version on success
+ */
+static int goodix_read_version(struct i2c_client *client, u16 *version)
+{
+ int error;
+ u8 buf[6];
+
+ error = goodix_i2c_read(client, GOODIX_REG_VERSION, buf, sizeof(buf));
+ if (error) {
+ dev_err(&client->dev, "read version failed: %d\n", error);
+ return error;
+ }
+
+ if (version)
+ *version = get_unaligned_le16(&buf[4]);
+
+ dev_info(&client->dev, "IC VERSION: %6ph\n", buf);
+
+ return 0;
+}
+
+/**
+ * goodix_i2c_test - I2C test function to check if the device answers.
+ *
+ * @client: the i2c client
+ */
+static int goodix_i2c_test(struct i2c_client *client)
+{
+ int retry = 0;
+ int error;
+ u8 test;
+
+ while (retry++ < 2) {
+ error = goodix_i2c_read(client, GOODIX_REG_CONFIG_DATA,
+ &test, 1);
+ if (!error)
+ return 0;
+
+ dev_err(&client->dev, "i2c test failed attempt %d: %d\n",
+ retry, error);
+ msleep(20);
+ }
+
+ return error;
+}
+
+/**
+ * goodix_request_input_dev - Allocate, populate and register the input device
+ *
+ * @ts: our goodix_ts_data pointer
+ *
+ * Must be called during probe
+ */
+static int goodix_request_input_dev(struct goodix_ts_data *ts)
+{
+ int error;
+
+ ts->input_dev = devm_input_allocate_device(&ts->client->dev);
+ if (!ts->input_dev) {
+ dev_err(&ts->client->dev, "Failed to allocate input device.");
+ return -ENOMEM;
+ }
+
+ ts->input_dev->evbit[0] = BIT_MASK(EV_SYN) |
+ BIT_MASK(EV_KEY) |
+ BIT_MASK(EV_ABS);
+
+ input_set_abs_params(ts->input_dev, ABS_MT_POSITION_X, 0,
+ ts->abs_x_max, 0, 0);
+ input_set_abs_params(ts->input_dev, ABS_MT_POSITION_Y, 0,
+ ts->abs_y_max, 0, 0);
+ input_set_abs_params(ts->input_dev, ABS_MT_WIDTH_MAJOR, 0, 255, 0, 0);
+ input_set_abs_params(ts->input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
+
+ input_mt_init_slots(ts->input_dev, GOODIX_MAX_CONTACTS,
+ INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+
+ ts->input_dev->name = "Goodix Capacitive TouchScreen";
+ ts->input_dev->phys = "input/ts";
+ ts->input_dev->id.bustype = BUS_I2C;
+ ts->input_dev->id.vendor = 0x0416;
+ ts->input_dev->id.product = 0x1001;
+ ts->input_dev->id.version = 10427;
+
+ error = input_register_device(ts->input_dev);
+ if (error) {
+ dev_err(&ts->client->dev,
+ "Failed to register input device: %d", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static int goodix_ts_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct goodix_ts_data *ts;
+ unsigned long irq_flags;
+ int error;
+ u16 version_info;
+
+ dev_dbg(&client->dev, "I2C Address: 0x%02x\n", client->addr);
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(&client->dev, "I2C check functionality failed.\n");
+ return -ENXIO;
+ }
+
+ ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ ts->client = client;
+ i2c_set_clientdata(client, ts);
+
+ error = goodix_i2c_test(client);
+ if (error) {
+ dev_err(&client->dev, "I2C communication failure: %d\n", error);
+ return error;
+ }
+
+ error = goodix_read_version(client, &version_info);
+ if (error) {
+ dev_err(&client->dev, "Read version failed.\n");
+ return error;
+ }
+
+ goodix_read_config(ts);
+
+ error = goodix_request_input_dev(ts);
+ if (error)
+ return error;
+
+ irq_flags = goodix_irq_flags[ts->int_trigger_type] | IRQF_ONESHOT;
+ error = devm_request_threaded_irq(&ts->client->dev, client->irq,
+ NULL, goodix_ts_irq_handler,
+ irq_flags, client->name, ts);
+ if (error) {
+ dev_err(&client->dev, "request IRQ failed: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static const struct i2c_device_id goodix_ts_id[] = {
+ { "GDIX1001:00", 0 },
+ { }
+};
+
+static const struct acpi_device_id goodix_acpi_match[] = {
+ { "GDIX1001", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, goodix_acpi_match);
+
+static struct i2c_driver goodix_ts_driver = {
+ .probe = goodix_ts_probe,
+ .id_table = goodix_ts_id,
+ .driver = {
+ .name = "Goodix-TS",
+ .owner = THIS_MODULE,
+ .acpi_match_table = goodix_acpi_match,
+ },
+};
+module_i2c_driver(goodix_ts_driver);
+
+MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
+MODULE_AUTHOR("Bastien Nocera <hadess@hadess.net>");
+MODULE_DESCRIPTION("Goodix touchscreen driver");
+MODULE_LICENSE("GPL v2");