--- /dev/null
+/*
+ * Driver for ChipOne icn8318 i2c touchscreen controller
+ *
+ * Copyright (c) 2015 Red Hat Inc.
+ *
+ * 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.
+ *
+ * Red Hat authors:
+ * 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/module.h>
+#include <linux/of.h>
+
+#define ICN8318_REG_POWER 4
+#define ICN8318_REG_TOUCHDATA 16
+
+#define ICN8318_POWER_ACTIVE 0
+#define ICN8318_POWER_MONITOR 1
+#define ICN8318_POWER_HIBERNATE 2
+
+#define ICN8318_MAX_TOUCHES 5
+
+struct icn8318_touch {
+ __u8 slot;
+ __be16 x;
+ __be16 y;
+ __u8 pressure; /* Seems more like finger width then pressure really */
+ __u8 event;
+/* The difference between 2 and 3 is unclear */
+#define ICN8318_EVENT_NO_DATA 1 /* No finger seen yet since wakeup */
+#define ICN8318_EVENT_UPDATE1 2 /* New or updated coordinates */
+#define ICN8318_EVENT_UPDATE2 3 /* New or updated coordinates */
+#define ICN8318_EVENT_END 4 /* Finger lifted */
+} __packed;
+
+struct icn8318_touch_data {
+ __u8 softbutton;
+ __u8 touch_count;
+ struct icn8318_touch touches[ICN8318_MAX_TOUCHES];
+} __packed;
+
+struct icn8318_data {
+ struct i2c_client *client;
+ struct input_dev *input;
+ struct gpio_desc *wake_gpio;
+ u32 max_x;
+ u32 max_y;
+ bool invert_x;
+ bool invert_y;
+ bool swap_x_y;
+};
+
+static int icn8318_read_touch_data(struct i2c_client *client,
+ struct icn8318_touch_data *touch_data)
+{
+ u8 reg = ICN8318_REG_TOUCHDATA;
+ struct i2c_msg msg[2] = {
+ {
+ .addr = client->addr,
+ .len = 1,
+ .buf = ®
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = sizeof(struct icn8318_touch_data),
+ .buf = (u8 *)touch_data
+ }
+ };
+
+ return i2c_transfer(client->adapter, msg, 2);
+}
+
+static inline bool icn8318_touch_active(u8 event)
+{
+ return (event == ICN8318_EVENT_UPDATE1) ||
+ (event == ICN8318_EVENT_UPDATE2);
+}
+
+static irqreturn_t icn8318_irq(int irq, void *dev_id)
+{
+ struct icn8318_data *data = dev_id;
+ struct device *dev = &data->client->dev;
+ struct icn8318_touch_data touch_data;
+ int i, ret, x, y;
+
+ ret = icn8318_read_touch_data(data->client, &touch_data);
+ if (ret < 0) {
+ dev_err(dev, "Error reading touch data: %d\n", ret);
+ return IRQ_HANDLED;
+ }
+
+ if (touch_data.softbutton) {
+ /*
+ * Other data is invalid when a softbutton is pressed.
+ * This needs some extra devicetree bindings to map the icn8318
+ * softbutton codes to evdev codes. Currently no known devices
+ * use this.
+ */
+ return IRQ_HANDLED;
+ }
+
+ if (touch_data.touch_count > ICN8318_MAX_TOUCHES) {
+ dev_warn(dev, "Too much touches %d > %d\n",
+ touch_data.touch_count, ICN8318_MAX_TOUCHES);
+ touch_data.touch_count = ICN8318_MAX_TOUCHES;
+ }
+
+ for (i = 0; i < touch_data.touch_count; i++) {
+ struct icn8318_touch *touch = &touch_data.touches[i];
+ bool act = icn8318_touch_active(touch->event);
+
+ input_mt_slot(data->input, touch->slot);
+ input_mt_report_slot_state(data->input, MT_TOOL_FINGER, act);
+ if (!act)
+ continue;
+
+ x = be16_to_cpu(touch->x);
+ y = be16_to_cpu(touch->y);
+
+ if (data->invert_x)
+ x = data->max_x - x;
+
+ if (data->invert_y)
+ y = data->max_y - y;
+
+ if (!data->swap_x_y) {
+ input_event(data->input, EV_ABS, ABS_MT_POSITION_X, x);
+ input_event(data->input, EV_ABS, ABS_MT_POSITION_Y, y);
+ } else {
+ input_event(data->input, EV_ABS, ABS_MT_POSITION_X, y);
+ input_event(data->input, EV_ABS, ABS_MT_POSITION_Y, x);
+ }
+ }
+
+ input_mt_sync_frame(data->input);
+ input_sync(data->input);
+
+ return IRQ_HANDLED;
+}
+
+static int icn8318_start(struct input_dev *dev)
+{
+ struct icn8318_data *data = input_get_drvdata(dev);
+
+ enable_irq(data->client->irq);
+ gpiod_set_value_cansleep(data->wake_gpio, 1);
+
+ return 0;
+}
+
+static void icn8318_stop(struct input_dev *dev)
+{
+ struct icn8318_data *data = input_get_drvdata(dev);
+
+ disable_irq(data->client->irq);
+ i2c_smbus_write_byte_data(data->client, ICN8318_REG_POWER,
+ ICN8318_POWER_HIBERNATE);
+ gpiod_set_value_cansleep(data->wake_gpio, 0);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int icn8318_suspend(struct device *dev)
+{
+ struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
+
+ mutex_lock(&data->input->mutex);
+ if (data->input->users)
+ icn8318_stop(data->input);
+ mutex_unlock(&data->input->mutex);
+
+ return 0;
+}
+
+static int icn8318_resume(struct device *dev)
+{
+ struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
+
+ mutex_lock(&data->input->mutex);
+ if (data->input->users)
+ icn8318_start(data->input);
+ mutex_unlock(&data->input->mutex);
+
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(icn8318_pm_ops, icn8318_suspend, icn8318_resume);
+
+static int icn8318_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct device_node *np = dev->of_node;
+ struct icn8318_data *data;
+ struct input_dev *input;
+ u32 fuzz_x = 0, fuzz_y = 0;
+ int error;
+
+ if (!client->irq) {
+ dev_err(dev, "Error no irq specified\n");
+ return -EINVAL;
+ }
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->wake_gpio = devm_gpiod_get(dev, "wake", GPIOD_OUT_LOW);
+ if (IS_ERR(data->wake_gpio)) {
+ error = PTR_ERR(data->wake_gpio);
+ if (error != -EPROBE_DEFER)
+ dev_err(dev, "Error getting wake gpio: %d\n", error);
+ return error;
+ }
+
+ if (of_property_read_u32(np, "touchscreen-size-x", &data->max_x) ||
+ of_property_read_u32(np, "touchscreen-size-y", &data->max_y)) {
+ dev_err(dev, "Error touchscreen-size-x and/or -y missing\n");
+ return -EINVAL;
+ }
+
+ /* Optional */
+ of_property_read_u32(np, "touchscreen-fuzz-x", &fuzz_x);
+ of_property_read_u32(np, "touchscreen-fuzz-y", &fuzz_y);
+ data->invert_x = of_property_read_bool(np, "touchscreen-inverted-x");
+ data->invert_y = of_property_read_bool(np, "touchscreen-inverted-y");
+ data->swap_x_y = of_property_read_bool(np, "touchscreen-swapped-x-y");
+
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ input->name = client->name;
+ input->id.bustype = BUS_I2C;
+ input->open = icn8318_start;
+ input->close = icn8318_stop;
+ input->dev.parent = dev;
+
+ if (!data->swap_x_y) {
+ input_set_abs_params(input, ABS_MT_POSITION_X, 0,
+ data->max_x, fuzz_x, 0);
+ input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
+ data->max_y, fuzz_y, 0);
+ } else {
+ input_set_abs_params(input, ABS_MT_POSITION_X, 0,
+ data->max_y, fuzz_y, 0);
+ input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
+ data->max_x, fuzz_x, 0);
+ }
+
+ error = input_mt_init_slots(input, ICN8318_MAX_TOUCHES,
+ INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+ if (error)
+ return error;
+
+ data->client = client;
+ data->input = input;
+ input_set_drvdata(input, data);
+
+ error = devm_request_threaded_irq(dev, client->irq, NULL, icn8318_irq,
+ IRQF_ONESHOT, client->name, data);
+ if (error) {
+ dev_err(dev, "Error requesting irq: %d\n", error);
+ return error;
+ }
+
+ /* Stop device till opened */
+ icn8318_stop(data->input);
+
+ error = input_register_device(input);
+ if (error)
+ return error;
+
+ i2c_set_clientdata(client, data);
+
+ return 0;
+}
+
+static const struct of_device_id icn8318_of_match[] = {
+ { .compatible = "chipone,icn8318" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, icn8318_of_match);
+
+/* This is useless for OF-enabled devices, but it is needed by I2C subsystem */
+static const struct i2c_device_id icn8318_i2c_id[] = {
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, icn8318_i2c_id);
+
+static struct i2c_driver icn8318_driver = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "chipone_icn8318",
+ .pm = &icn8318_pm_ops,
+ .of_match_table = icn8318_of_match,
+ },
+ .probe = icn8318_probe,
+ .id_table = icn8318_i2c_id,
+};
+
+module_i2c_driver(icn8318_driver);
+
+MODULE_DESCRIPTION("ChipOne icn8318 I2C Touchscreen Driver");
+MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff