// 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 = ® }, { .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");