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path: root/drivers/input/touchscreen/chipone_icn8318.c
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Diffstat (limited to 'drivers/input/touchscreen/chipone_icn8318.c')
-rw-r--r--drivers/input/touchscreen/chipone_icn8318.c271
1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/chipone_icn8318.c b/drivers/input/touchscreen/chipone_icn8318.c
new file mode 100644
index 0000000000..d6876d10b2
--- /dev/null
+++ b/drivers/input/touchscreen/chipone_icn8318.c
@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for ChipOne icn8318 i2c touchscreen controller
+ *
+ * Copyright (c) 2015 Red Hat Inc.
+ *
+ * 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/input/touchscreen.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;
+ struct touchscreen_properties prop;
+};
+
+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 = &reg
+ },
+ {
+ .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;
+
+ 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;
+
+ touchscreen_report_pos(data->input, &data->prop,
+ be16_to_cpu(touch->x),
+ be16_to_cpu(touch->y), true);
+ }
+
+ 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);
+}
+
+static int icn8318_suspend(struct device *dev)
+{
+ struct icn8318_data *data = i2c_get_clientdata(to_i2c_client(dev));
+
+ mutex_lock(&data->input->mutex);
+ if (input_device_enabled(data->input))
+ 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 (input_device_enabled(data->input))
+ icn8318_start(data->input);
+ mutex_unlock(&data->input->mutex);
+
+ return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(icn8318_pm_ops, icn8318_suspend, icn8318_resume);
+
+static int icn8318_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct icn8318_data *data;
+ struct input_dev *input;
+ 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))
+ return dev_err_probe(dev, PTR_ERR(data->wake_gpio), "Error getting wake gpio\n");
+
+ 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;
+
+ input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
+ input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
+
+ touchscreen_parse_properties(input, true, &data->prop);
+ if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
+ !input_abs_get_max(input, ABS_MT_POSITION_Y)) {
+ dev_err(dev, "Error touchscreen-size-x and/or -y missing\n");
+ return -EINVAL;
+ }
+
+ 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 = {
+ .name = "chipone_icn8318",
+ .pm = pm_sleep_ptr(&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");