#include <linux/delay.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/regulator/consumer.h>
#include <linux/unaligned.h>
#define ZET6223_MAX_FINGERS 16
#define ZET6223_MAX_PKT_SIZE (3 + 4 * ZET6223_MAX_FINGERS)
#define ZET6223_CMD_INFO 0xB2
#define ZET6223_CMD_INFO_LENGTH 17
#define ZET6223_VALID_PACKET 0x3c
#define ZET6223_POWER_ON_DELAY_MSEC 30
struct zet6223_ts {
struct i2c_client *client;
struct input_dev *input;
struct touchscreen_properties prop;
struct regulator_bulk_data supplies[2];
u16 max_x;
u16 max_y;
u8 fingernum;
};
static int zet6223_start(struct input_dev *dev)
{
struct zet6223_ts *ts = input_get_drvdata(dev);
enable_irq(ts->client->irq);
return 0;
}
static void zet6223_stop(struct input_dev *dev)
{
struct zet6223_ts *ts = input_get_drvdata(dev);
disable_irq(ts->client->irq);
}
static irqreturn_t zet6223_irq(int irq, void *dev_id)
{
struct zet6223_ts *ts = dev_id;
u16 finger_bits;
u8 bufsize = 3 + 4 * ts->fingernum;
u8 buf[ZET6223_MAX_PKT_SIZE];
int i;
int ret;
int error;
ret = i2c_master_recv(ts->client, buf, bufsize);
if (ret != bufsize) {
error = ret < 0 ? ret : -EIO;
dev_err_ratelimited(&ts->client->dev,
"Error reading input data: %d\n", error);
return IRQ_HANDLED;
}
if (buf[0] != ZET6223_VALID_PACKET)
return IRQ_HANDLED;
finger_bits = get_unaligned_be16(buf + 1);
for (i = 0; i < ts->fingernum; i++) {
if (!(finger_bits & BIT(15 - i)))
continue;
input_mt_slot(ts->input, i);
input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
input_event(ts->input, EV_ABS, ABS_MT_POSITION_X,
((buf[i + 3] >> 4) << 8) + buf[i + 4]);
input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y,
((buf[i + 3] & 0xF) << 8) + buf[i + 5]);
}
input_mt_sync_frame(ts->input);
input_sync(ts->input);
return IRQ_HANDLED;
}
static void zet6223_power_off(void *_ts)
{
struct zet6223_ts *ts = _ts;
regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
}
static int zet6223_power_on(struct zet6223_ts *ts)
{
struct device *dev = &ts->client->dev;
int error;
ts->supplies[0].supply = "vio";
ts->supplies[1].supply = "vcc";
error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies),
ts->supplies);
if (error)
return error;
error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
if (error)
return error;
msleep(ZET6223_POWER_ON_DELAY_MSEC);
error = devm_add_action_or_reset(dev, zet6223_power_off, ts);
if (error) {
dev_err(dev, "failed to install poweroff action: %d\n", error);
return error;
}
return 0;
}
static int zet6223_query_device(struct zet6223_ts *ts)
{
u8 buf[ZET6223_CMD_INFO_LENGTH];
u8 cmd = ZET6223_CMD_INFO;
int ret;
int error;
ret = i2c_master_send(ts->client, &cmd, sizeof(cmd));
if (ret != sizeof(cmd)) {
error = ret < 0 ? ret : -EIO;
dev_err(&ts->client->dev,
"touchpanel info cmd failed: %d\n", error);
return error;
}
ret = i2c_master_recv(ts->client, buf, sizeof(buf));
if (ret != sizeof(buf)) {
error = ret < 0 ? ret : -EIO;
dev_err(&ts->client->dev,
"failed to retrieve touchpanel info: %d\n", error);
return error;
}
ts->fingernum = buf[15] & 0x7F;
if (ts->fingernum > ZET6223_MAX_FINGERS) {
dev_warn(&ts->client->dev,
"touchpanel reports %d fingers, limiting to %d\n",
ts->fingernum, ZET6223_MAX_FINGERS);
ts->fingernum = ZET6223_MAX_FINGERS;
}
ts->max_x = get_unaligned_le16(&buf[8]);
ts->max_y = get_unaligned_le16(&buf[10]);
return 0;
}
static int zet6223_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct zet6223_ts *ts;
struct input_dev *input;
int error;
if (!client->irq) {
dev_err(dev, "no irq specified\n");
return -EINVAL;
}
ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
if (!ts)
return -ENOMEM;
ts->client = client;
error = zet6223_power_on(ts);
if (error)
return error;
error = zet6223_query_device(ts);
if (error)
return error;
ts->input = input = devm_input_allocate_device(dev);
if (!input)
return -ENOMEM;
input_set_drvdata(input, ts);
input->name = client->name;
input->id.bustype = BUS_I2C;
input->open = zet6223_start;
input->close = zet6223_stop;
input_set_abs_params(input, ABS_MT_POSITION_X, 0, ts->max_x, 0, 0);
input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ts->max_y, 0, 0);
touchscreen_parse_properties(input, true, &ts->prop);
error = input_mt_init_slots(input, ts->fingernum,
INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
if (error)
return error;
error = devm_request_threaded_irq(dev, client->irq, NULL, zet6223_irq,
IRQF_ONESHOT, client->name, ts);
if (error) {
dev_err(dev, "failed to request irq %d: %d\n",
client->irq, error);
return error;
}
zet6223_stop(input);
error = input_register_device(input);
if (error)
return error;
return 0;
}
static const struct of_device_id zet6223_of_match[] = {
{ .compatible = "zeitec,zet6223" },
{ }
};
MODULE_DEVICE_TABLE(of, zet6223_of_match);
static const struct i2c_device_id zet6223_id[] = {
{ "zet6223" },
{ }
};
MODULE_DEVICE_TABLE(i2c, zet6223_id);
static struct i2c_driver zet6223_driver = {
.driver = {
.name = "zet6223",
.of_match_table = zet6223_of_match,
},
.probe = zet6223_probe,
.id_table = zet6223_id
};
module_i2c_driver(zet6223_driver);
MODULE_AUTHOR("Jelle van der Waa <jelle@vdwaa.nl>");
MODULE_DESCRIPTION("ZEITEC zet622x I2C touchscreen driver");
MODULE_LICENSE("GPL");
