Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add I2C attached EETI EXC3000 multi touch driver #2347

Merged
merged 3 commits into from
Jan 19, 2018
Merged
Changes from 1 commit
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Next Next commit
Input: add I2C attached EETI EXC3000 multi touch driver
commit 7e577a1 upstream.
beware: code adapted to use the old timer API.

The 3000 series have a new protocol which allows to report up to 5 points
in a single 66 byte frame. One must always read in 66 byte frames.
To support up to 10 points, two consecutive frames need to be read:
The first frame says how many points until sync.
The second frame must say zero points or both frames must be discarded.

To be able to work with the higher 400KHz I2C bus rate, one must
successfully send a special package prior _each_ read or the controller
will refuse to cooperate.

This is a minimal implementation based on egalax_i2c.c (which can be found
on the internet) and egalax_ts.c but without the vendor interface and no
power management support.

Signed-off-by: Ahmet Inan <[email protected]>
Acked-by: Rob Herring <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
  • Loading branch information
Ahmet Inan authored and Ahmet Inan committed Jan 19, 2018
commit 6fc771a33bca026c3fdfeeede53feb32aef63c1f
27 changes: 27 additions & 0 deletions Documentation/devicetree/bindings/input/touchscreen/exc3000.txt
Original file line number Diff line number Diff line change
@@ -0,0 +1,27 @@
* EETI EXC3000 Multiple Touch Controller

Required properties:
- compatible: must be "eeti,exc3000"
- reg: i2c slave address
- interrupt-parent: the phandle for the interrupt controller
- interrupts: touch controller interrupt
- touchscreen-size-x: See touchscreen.txt
- touchscreen-size-y: See touchscreen.txt

Optional properties:
- touchscreen-inverted-x: See touchscreen.txt
- touchscreen-inverted-y: See touchscreen.txt
- touchscreen-swapped-x-y: See touchscreen.txt

Example:

touchscreen@2a {
compatible = "eeti,exc3000";
reg = <0x2a>;
interrupt-parent = <&gpio1>;
interrupts = <9 IRQ_TYPE_LEVEL_LOW>;
touchscreen-size-x = <4096>;
touchscreen-size-y = <4096>;
touchscreen-inverted-x;
touchscreen-swapped-x-y;
};
10 changes: 10 additions & 0 deletions drivers/input/touchscreen/Kconfig
Original file line number Diff line number Diff line change
@@ -314,6 +314,16 @@ config TOUCHSCREEN_EGALAX_SERIAL
To compile this driver as a module, choose M here: the
module will be called egalax_ts_serial.

config TOUCHSCREEN_EXC3000
tristate "EETI EXC3000 multi-touch panel support"
depends on I2C
help
Say Y here to enable support for I2C connected EETI
EXC3000 multi-touch panels.

To compile this driver as a module, choose M here: the
module will be called exc3000.

config TOUCHSCREEN_FUJITSU
tristate "Fujitsu serial touchscreen"
select SERIO
1 change: 1 addition & 0 deletions drivers/input/touchscreen/Makefile
Original file line number Diff line number Diff line change
@@ -38,6 +38,7 @@ obj-$(CONFIG_TOUCHSCREEN_ELAN) += elants_i2c.o
obj-$(CONFIG_TOUCHSCREEN_ELO) += elo.o
obj-$(CONFIG_TOUCHSCREEN_EGALAX) += egalax_ts.o
obj-$(CONFIG_TOUCHSCREEN_EGALAX_SERIAL) += egalax_ts_serial.o
obj-$(CONFIG_TOUCHSCREEN_EXC3000) += exc3000.o
obj-$(CONFIG_TOUCHSCREEN_FUJITSU) += fujitsu_ts.o
obj-$(CONFIG_TOUCHSCREEN_GOODIX) += goodix.o
obj-$(CONFIG_TOUCHSCREEN_ILI210X) += ili210x.o
223 changes: 223 additions & 0 deletions drivers/input/touchscreen/exc3000.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,223 @@
/*
* Driver for I2C connected EETI EXC3000 multiple touch controller
*
* Copyright (C) 2017 Ahmet Inan <[email protected]>
*
* minimal implementation based on egalax_ts.c and egalax_i2c.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/

#include <linux/bitops.h>
#include <linux/device.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/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_POINT 10
#define EXC3000_MT_EVENT 6
#define EXC3000_TIMEOUT_MS 100

struct exc3000_data {
struct i2c_client *client;
struct input_dev *input;
struct touchscreen_properties prop;
struct timer_list timer;
u8 buf[2 * EXC3000_LEN_FRAME];
};

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(unsigned long d)
{
struct exc3000_data *data = (void *)d;

input_mt_sync_frame(data->input);
input_sync(data->input);
}

static int exc3000_read_frame(struct i2c_client *client, u8 *buf)
{
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 ||
buf[2] != EXC3000_MT_EVENT)
return -EINVAL;

return 0;
}

static int exc3000_read_data(struct i2c_client *client,
u8 *buf, int *n_slots)
{
int error;

error = exc3000_read_frame(client, buf);
if (error)
return error;

*n_slots = buf[3];
if (!*n_slots || *n_slots > EXC3000_NUM_SLOTS)
return -EINVAL;

if (*n_slots > EXC3000_SLOTS_PER_FRAME) {
/* Read 2nd frame to get the rest of the contacts. */
error = exc3000_read_frame(client, buf + EXC3000_LEN_FRAME);
if (error)
return error;

/* 2nd chunk must have number of contacts set to 0. */
if (buf[EXC3000_LEN_FRAME + 3] != 0)
return -EINVAL;
}

return 0;
}

static irqreturn_t exc3000_interrupt(int irq, void *dev_id)
{
struct exc3000_data *data = dev_id;
struct input_dev *input = data->input;
u8 *buf = data->buf;
int slots, total_slots;
int error;

error = exc3000_read_data(data->client, buf, &total_slots);
if (error) {
/* Schedule a timer to release "stuck" contacts */
mod_timer(&data->timer,
jiffies + msecs_to_jiffies(EXC3000_TIMEOUT_MS));
goto out;
}

/*
* We read full state successfully, no contacts will be "stuck".
*/
del_timer_sync(&data->timer);

while (total_slots > 0) {
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);

out:
return IRQ_HANDLED;
}

static int exc3000_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct exc3000_data *data;
struct input_dev *input;
int error;

data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;

data->client = client;
setup_timer(&data->timer, exc3000_timer, (unsigned long)data);

input = devm_input_allocate_device(&client->dev);
if (!input)
return -ENOMEM;

data->input = input;

input->name = "EETI EXC3000 Touch Screen";
input->id.bustype = BUS_I2C;

input_set_abs_params(input, ABS_MT_POSITION_X, 0, 4095, 0, 0);
input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 4095, 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_request_threaded_irq(&client->dev, client->irq,
NULL, exc3000_interrupt, IRQF_ONESHOT,
client->name, data);
if (error)
return error;

return 0;
}

static const struct i2c_device_id exc3000_id[] = {
{ "exc3000", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, exc3000_id);

#ifdef CONFIG_OF
static const struct of_device_id exc3000_of_match[] = {
{ .compatible = "eeti,exc3000" },
{ }
};
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 = exc3000_probe,
};

module_i2c_driver(exc3000_driver);

MODULE_AUTHOR("Ahmet Inan <[email protected]>");
MODULE_DESCRIPTION("I2C connected EETI EXC3000 multiple touch controller driver");
MODULE_LICENSE("GPL v2");