| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Driver for I2C connected EETI EXC3000 multiple touch controller |
| * |
| * Copyright (C) 2017 Ahmet Inan <inan@distec.de> |
| * |
| * minimal implementation based on egalax_ts.c and egalax_i2c.c |
| */ |
| |
| #include <linux/bitops.h> |
| #include <linux/delay.h> |
| #include <linux/device.h> |
| #include <linux/gpio/consumer.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/of.h> |
| #include <linux/sizes.h> |
| #include <linux/timer.h> |
| #include <asm/unaligned.h> |
| |
| #define EXC3000_NUM_SLOTS 10 |
| #define EXC3000_SLOTS_PER_FRAME 5 |
| #define EXC3000_LEN_FRAME 66 |
| #define EXC3000_LEN_VENDOR_REQUEST 68 |
| #define EXC3000_LEN_POINT 10 |
| |
| #define EXC3000_LEN_MODEL_NAME 16 |
| #define EXC3000_LEN_FW_VERSION 16 |
| |
| #define EXC3000_VENDOR_EVENT 0x03 |
| #define EXC3000_MT1_EVENT 0x06 |
| #define EXC3000_MT2_EVENT 0x18 |
| |
| #define EXC3000_TIMEOUT_MS 100 |
| |
| #define EXC3000_RESET_MS 10 |
| #define EXC3000_READY_MS 100 |
| |
| static const struct i2c_device_id exc3000_id[]; |
| |
| struct eeti_dev_info { |
| const char *name; |
| int max_xy; |
| }; |
| |
| enum eeti_dev_id { |
| EETI_EXC3000, |
| EETI_EXC80H60, |
| EETI_EXC80H84, |
| }; |
| |
| static struct eeti_dev_info exc3000_info[] = { |
| [EETI_EXC3000] = { |
| .name = "EETI EXC3000 Touch Screen", |
| .max_xy = SZ_4K - 1, |
| }, |
| [EETI_EXC80H60] = { |
| .name = "EETI EXC80H60 Touch Screen", |
| .max_xy = SZ_16K - 1, |
| }, |
| [EETI_EXC80H84] = { |
| .name = "EETI EXC80H84 Touch Screen", |
| .max_xy = SZ_16K - 1, |
| }, |
| }; |
| |
| struct exc3000_data { |
| struct i2c_client *client; |
| const struct eeti_dev_info *info; |
| struct input_dev *input; |
| struct touchscreen_properties prop; |
| struct gpio_desc *reset; |
| struct timer_list timer; |
| u8 buf[2 * EXC3000_LEN_FRAME]; |
| struct completion wait_event; |
| struct mutex query_lock; |
| }; |
| |
| static void exc3000_report_slots(struct input_dev *input, |
| struct touchscreen_properties *prop, |
| const u8 *buf, int num) |
| { |
| for (; num--; buf += EXC3000_LEN_POINT) { |
| if (buf[0] & BIT(0)) { |
| input_mt_slot(input, buf[1]); |
| input_mt_report_slot_state(input, MT_TOOL_FINGER, true); |
| touchscreen_report_pos(input, prop, |
| get_unaligned_le16(buf + 2), |
| get_unaligned_le16(buf + 4), |
| true); |
| } |
| } |
| } |
| |
| static void exc3000_timer(struct timer_list *t) |
| { |
| struct exc3000_data *data = from_timer(data, t, timer); |
| |
| input_mt_sync_frame(data->input); |
| input_sync(data->input); |
| } |
| |
| static inline void exc3000_schedule_timer(struct exc3000_data *data) |
| { |
| mod_timer(&data->timer, jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS)); |
| } |
| |
| static void exc3000_shutdown_timer(void *timer) |
| { |
| timer_shutdown_sync(timer); |
| } |
| |
| static int exc3000_read_frame(struct exc3000_data *data, u8 *buf) |
| { |
| struct i2c_client *client = data->client; |
| int ret; |
| |
| ret = i2c_master_send(client, "'", 2); |
| if (ret < 0) |
| return ret; |
| |
| if (ret != 2) |
| return -EIO; |
| |
| ret = i2c_master_recv(client, buf, EXC3000_LEN_FRAME); |
| if (ret < 0) |
| return ret; |
| |
| if (ret != EXC3000_LEN_FRAME) |
| return -EIO; |
| |
| if (get_unaligned_le16(buf) != EXC3000_LEN_FRAME) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| static int exc3000_handle_mt_event(struct exc3000_data *data) |
| { |
| struct input_dev *input = data->input; |
| int ret, total_slots; |
| u8 *buf = data->buf; |
| |
| total_slots = buf[3]; |
| if (!total_slots || total_slots > EXC3000_NUM_SLOTS) { |
| ret = -EINVAL; |
| goto out_fail; |
| } |
| |
| if (total_slots > EXC3000_SLOTS_PER_FRAME) { |
| /* Read 2nd frame to get the rest of the contacts. */ |
| ret = exc3000_read_frame(data, buf + EXC3000_LEN_FRAME); |
| if (ret) |
| goto out_fail; |
| |
| /* 2nd chunk must have number of contacts set to 0. */ |
| if (buf[EXC3000_LEN_FRAME + 3] != 0) { |
| ret = -EINVAL; |
| goto out_fail; |
| } |
| } |
| |
| /* |
| * We read full state successfully, no contacts will be "stuck". |
| */ |
| del_timer_sync(&data->timer); |
| |
| while (total_slots > 0) { |
| int slots = min(total_slots, EXC3000_SLOTS_PER_FRAME); |
| |
| exc3000_report_slots(input, &data->prop, buf + 4, slots); |
| total_slots -= slots; |
| buf += EXC3000_LEN_FRAME; |
| } |
| |
| input_mt_sync_frame(input); |
| input_sync(input); |
| |
| return 0; |
| |
| out_fail: |
| /* Schedule a timer to release "stuck" contacts */ |
| exc3000_schedule_timer(data); |
| |
| return ret; |
| } |
| |
| static irqreturn_t exc3000_interrupt(int irq, void *dev_id) |
| { |
| struct exc3000_data *data = dev_id; |
| u8 *buf = data->buf; |
| int ret; |
| |
| ret = exc3000_read_frame(data, buf); |
| if (ret) { |
| /* Schedule a timer to release "stuck" contacts */ |
| exc3000_schedule_timer(data); |
| goto out; |
| } |
| |
| switch (buf[2]) { |
| case EXC3000_VENDOR_EVENT: |
| complete(&data->wait_event); |
| break; |
| |
| case EXC3000_MT1_EVENT: |
| case EXC3000_MT2_EVENT: |
| exc3000_handle_mt_event(data); |
| break; |
| |
| default: |
| break; |
| } |
| |
| out: |
| return IRQ_HANDLED; |
| } |
| |
| static int exc3000_vendor_data_request(struct exc3000_data *data, u8 *request, |
| u8 request_len, u8 *response, int timeout) |
| { |
| u8 buf[EXC3000_LEN_VENDOR_REQUEST] = { 0x67, 0x00, 0x42, 0x00, 0x03 }; |
| int ret; |
| unsigned long time_left; |
| |
| mutex_lock(&data->query_lock); |
| |
| reinit_completion(&data->wait_event); |
| |
| buf[5] = request_len; |
| memcpy(&buf[6], request, request_len); |
| |
| ret = i2c_master_send(data->client, buf, EXC3000_LEN_VENDOR_REQUEST); |
| if (ret < 0) |
| goto out_unlock; |
| |
| if (response) { |
| time_left = wait_for_completion_timeout(&data->wait_event, |
| timeout * HZ); |
| if (time_left == 0) { |
| ret = -ETIMEDOUT; |
| goto out_unlock; |
| } |
| |
| if (data->buf[3] >= EXC3000_LEN_FRAME) { |
| ret = -ENOSPC; |
| goto out_unlock; |
| } |
| |
| memcpy(response, &data->buf[4], data->buf[3]); |
| ret = data->buf[3]; |
| } |
| |
| out_unlock: |
| mutex_unlock(&data->query_lock); |
| |
| return ret; |
| } |
| |
| static ssize_t fw_version_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct exc3000_data *data = i2c_get_clientdata(client); |
| u8 response[EXC3000_LEN_FRAME]; |
| int ret; |
| |
| /* query bootloader info */ |
| ret = exc3000_vendor_data_request(data, |
| (u8[]){0x39, 0x02}, 2, response, 1); |
| if (ret < 0) |
| return ret; |
| |
| /* |
| * If the bootloader version is non-zero then the device is in |
| * bootloader mode and won't answer a query for the application FW |
| * version, so we just use the bootloader version info. |
| */ |
| if (response[2] || response[3]) |
| return sprintf(buf, "%d.%d\n", response[2], response[3]); |
| |
| ret = exc3000_vendor_data_request(data, (u8[]){'D'}, 1, response, 1); |
| if (ret < 0) |
| return ret; |
| |
| return sprintf(buf, "%s\n", &response[1]); |
| } |
| static DEVICE_ATTR_RO(fw_version); |
| |
| static ssize_t model_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct exc3000_data *data = i2c_get_clientdata(client); |
| u8 response[EXC3000_LEN_FRAME]; |
| int ret; |
| |
| ret = exc3000_vendor_data_request(data, (u8[]){'E'}, 1, response, 1); |
| if (ret < 0) |
| return ret; |
| |
| return sprintf(buf, "%s\n", &response[1]); |
| } |
| static DEVICE_ATTR_RO(model); |
| |
| static ssize_t type_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct exc3000_data *data = i2c_get_clientdata(client); |
| u8 response[EXC3000_LEN_FRAME]; |
| int ret; |
| |
| ret = exc3000_vendor_data_request(data, (u8[]){'F'}, 1, response, 1); |
| if (ret < 0) |
| return ret; |
| |
| return sprintf(buf, "%s\n", &response[1]); |
| } |
| static DEVICE_ATTR_RO(type); |
| |
| static struct attribute *sysfs_attrs[] = { |
| &dev_attr_fw_version.attr, |
| &dev_attr_model.attr, |
| &dev_attr_type.attr, |
| NULL |
| }; |
| |
| static struct attribute_group exc3000_attribute_group = { |
| .attrs = sysfs_attrs |
| }; |
| |
| static int exc3000_probe(struct i2c_client *client) |
| { |
| struct exc3000_data *data; |
| struct input_dev *input; |
| int error, max_xy, retry; |
| |
| data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); |
| if (!data) |
| return -ENOMEM; |
| |
| data->client = client; |
| data->info = device_get_match_data(&client->dev); |
| if (!data->info) { |
| enum eeti_dev_id eeti_dev_id = |
| i2c_match_id(exc3000_id, client)->driver_data; |
| data->info = &exc3000_info[eeti_dev_id]; |
| } |
| timer_setup(&data->timer, exc3000_timer, 0); |
| init_completion(&data->wait_event); |
| mutex_init(&data->query_lock); |
| |
| data->reset = devm_gpiod_get_optional(&client->dev, "reset", |
| GPIOD_OUT_HIGH); |
| if (IS_ERR(data->reset)) |
| return PTR_ERR(data->reset); |
| |
| if (data->reset) { |
| msleep(EXC3000_RESET_MS); |
| gpiod_set_value_cansleep(data->reset, 0); |
| msleep(EXC3000_READY_MS); |
| } |
| |
| input = devm_input_allocate_device(&client->dev); |
| if (!input) |
| return -ENOMEM; |
| |
| data->input = input; |
| input_set_drvdata(input, data); |
| |
| input->name = data->info->name; |
| input->id.bustype = BUS_I2C; |
| |
| max_xy = data->info->max_xy; |
| input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0); |
| input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0); |
| |
| touchscreen_parse_properties(input, true, &data->prop); |
| |
| error = input_mt_init_slots(input, EXC3000_NUM_SLOTS, |
| INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED); |
| if (error) |
| return error; |
| |
| error = input_register_device(input); |
| if (error) |
| return error; |
| |
| error = devm_add_action_or_reset(&client->dev, exc3000_shutdown_timer, |
| &data->timer); |
| if (error) |
| return error; |
| |
| error = devm_request_threaded_irq(&client->dev, client->irq, |
| NULL, exc3000_interrupt, IRQF_ONESHOT, |
| client->name, data); |
| if (error) |
| return error; |
| |
| /* |
| * I²C does not have built-in recovery, so retry on failure. This |
| * ensures, that the device probe will not fail for temporary issues |
| * on the bus. This is not needed for the sysfs calls (userspace |
| * will receive the error code and can start another query) and |
| * cannot be done for touch events (but that only means loosing one |
| * or two touch events anyways). |
| */ |
| for (retry = 0; retry < 3; retry++) { |
| u8 response[EXC3000_LEN_FRAME]; |
| |
| error = exc3000_vendor_data_request(data, (u8[]){'E'}, 1, |
| response, 1); |
| if (error > 0) { |
| dev_dbg(&client->dev, "TS Model: %s", &response[1]); |
| error = 0; |
| break; |
| } |
| dev_warn(&client->dev, "Retry %d get EETI EXC3000 model: %d\n", |
| retry + 1, error); |
| } |
| |
| if (error) |
| return error; |
| |
| i2c_set_clientdata(client, data); |
| |
| error = devm_device_add_group(&client->dev, &exc3000_attribute_group); |
| if (error) |
| return error; |
| |
| return 0; |
| } |
| |
| static const struct i2c_device_id exc3000_id[] = { |
| { "exc3000", EETI_EXC3000 }, |
| { "exc80h60", EETI_EXC80H60 }, |
| { "exc80h84", EETI_EXC80H84 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, exc3000_id); |
| |
| #ifdef CONFIG_OF |
| static const struct of_device_id exc3000_of_match[] = { |
| { .compatible = "eeti,exc3000", .data = &exc3000_info[EETI_EXC3000] }, |
| { .compatible = "eeti,exc80h60", .data = &exc3000_info[EETI_EXC80H60] }, |
| { .compatible = "eeti,exc80h84", .data = &exc3000_info[EETI_EXC80H84] }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, exc3000_of_match); |
| #endif |
| |
| static struct i2c_driver exc3000_driver = { |
| .driver = { |
| .name = "exc3000", |
| .of_match_table = of_match_ptr(exc3000_of_match), |
| }, |
| .id_table = exc3000_id, |
| .probe_new = exc3000_probe, |
| }; |
| |
| module_i2c_driver(exc3000_driver); |
| |
| MODULE_AUTHOR("Ahmet Inan <inan@distec.de>"); |
| MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver"); |
| MODULE_LICENSE("GPL v2"); |