blob: a4030cc9ff60d7031e4f988f7446491dafcfc0ea [file] [log] [blame]
// 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/acpi.h>
#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/regulator/consumer.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 *exc3000_attrs[] = {
&dev_attr_fw_version.attr,
&dev_attr_model.attr,
&dev_attr_type.attr,
NULL
};
ATTRIBUTE_GROUPS(exc3000);
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);
/* For proper reset sequence, enable power while reset asserted */
error = devm_regulator_get_enable(&client->dev, "vdd");
if (error && error != -ENODEV)
return dev_err_probe(&client->dev, error,
"failed to request vdd regulator\n");
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);
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
#ifdef CONFIG_ACPI
static const struct acpi_device_id exc3000_acpi_match[] = {
{ "EGA00001", .driver_data = (kernel_ulong_t)&exc3000_info[EETI_EXC80H60] },
{ }
};
MODULE_DEVICE_TABLE(acpi, exc3000_acpi_match);
#endif
static struct i2c_driver exc3000_driver = {
.driver = {
.name = "exc3000",
.dev_groups = exc3000_groups,
.of_match_table = of_match_ptr(exc3000_of_match),
.acpi_match_table = ACPI_PTR(exc3000_acpi_match),
},
.id_table = exc3000_id,
.probe = 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");