#include <linux/bits.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/unaligned.h>
#define WACOM_TIP_SWITCH BIT(0)
#define WACOM_BARREL_SWITCH BIT(1)
#define WACOM_ERASER BIT(2)
#define WACOM_INVERT BIT(3)
#define WACOM_BARREL_SWITCH_2 BIT(4)
#define WACOM_IN_PROXIMITY BIT(5)
#define WACOM_COMMAND_LSB 0x04
#define WACOM_COMMAND_MSB 0x00
#define WACOM_DATA_LSB 0x05
#define WACOM_DATA_MSB 0x00
#define REPORT_FEATURE 0x30
#define OPCODE_GET_REPORT 0x02
#define WACOM_QUERY_REPORT 3
#define WACOM_QUERY_SIZE 19
struct wacom_features {
int x_max;
int y_max;
int pressure_max;
char fw_version;
};
struct wacom_i2c {
struct i2c_client *client;
struct input_dev *input;
u8 data[WACOM_QUERY_SIZE];
bool prox;
int tool;
};
static int wacom_query_device(struct i2c_client *client,
struct wacom_features *features)
{
u8 get_query_data_cmd[] = {
WACOM_COMMAND_LSB,
WACOM_COMMAND_MSB,
REPORT_FEATURE | WACOM_QUERY_REPORT,
OPCODE_GET_REPORT,
WACOM_DATA_LSB,
WACOM_DATA_MSB,
};
u8 data[WACOM_QUERY_SIZE];
int ret;
struct i2c_msg msgs[] = {
{
.addr = client->addr,
.flags = 0,
.len = sizeof(get_query_data_cmd),
.buf = get_query_data_cmd,
},
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = sizeof(data),
.buf = data,
},
};
ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (ret < 0)
return ret;
if (ret != ARRAY_SIZE(msgs))
return -EIO;
features->x_max = get_unaligned_le16(&data[3]);
features->y_max = get_unaligned_le16(&data[5]);
features->pressure_max = get_unaligned_le16(&data[11]);
features->fw_version = get_unaligned_le16(&data[13]);
dev_dbg(&client->dev,
"x_max:%d, y_max:%d, pressure:%d, fw:%d\n",
features->x_max, features->y_max,
features->pressure_max, features->fw_version);
return 0;
}
static irqreturn_t wacom_i2c_irq(int irq, void *dev_id)
{
struct wacom_i2c *wac_i2c = dev_id;
struct input_dev *input = wac_i2c->input;
u8 *data = wac_i2c->data;
unsigned int x, y, pressure;
unsigned char tsw, f1, f2, ers;
int error;
error = i2c_master_recv(wac_i2c->client,
wac_i2c->data, sizeof(wac_i2c->data));
if (error < 0)
goto out;
tsw = data[3] & WACOM_TIP_SWITCH;
ers = data[3] & WACOM_ERASER;
f1 = data[3] & WACOM_BARREL_SWITCH;
f2 = data[3] & WACOM_BARREL_SWITCH_2;
x = le16_to_cpup((__le16 *)&data[4]);
y = le16_to_cpup((__le16 *)&data[6]);
pressure = le16_to_cpup((__le16 *)&data[8]);
if (!wac_i2c->prox)
wac_i2c->tool = (data[3] & (WACOM_ERASER | WACOM_INVERT)) ?
BTN_TOOL_RUBBER : BTN_TOOL_PEN;
wac_i2c->prox = data[3] & WACOM_IN_PROXIMITY;
input_report_key(input, BTN_TOUCH, tsw || ers);
input_report_key(input, wac_i2c->tool, wac_i2c->prox);
input_report_key(input, BTN_STYLUS, f1);
input_report_key(input, BTN_STYLUS2, f2);
input_report_abs(input, ABS_X, x);
input_report_abs(input, ABS_Y, y);
input_report_abs(input, ABS_PRESSURE, pressure);
input_sync(input);
out:
return IRQ_HANDLED;
}
static int wacom_i2c_open(struct input_dev *dev)
{
struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
struct i2c_client *client = wac_i2c->client;
enable_irq(client->irq);
return 0;
}
static void wacom_i2c_close(struct input_dev *dev)
{
struct wacom_i2c *wac_i2c = input_get_drvdata(dev);
struct i2c_client *client = wac_i2c->client;
disable_irq(client->irq);
}
static int wacom_i2c_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct wacom_i2c *wac_i2c;
struct input_dev *input;
struct wacom_features features = { 0 };
int error;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
dev_err(dev, "i2c_check_functionality error\n");
return -EIO;
}
error = wacom_query_device(client, &features);
if (error)
return error;
wac_i2c = devm_kzalloc(dev, sizeof(*wac_i2c), GFP_KERNEL);
if (!wac_i2c)
return -ENOMEM;
wac_i2c->client = client;
input = devm_input_allocate_device(dev);
if (!input)
return -ENOMEM;
wac_i2c->input = input;
input->name = "Wacom I2C Digitizer";
input->id.bustype = BUS_I2C;
input->id.vendor = 0x56a;
input->id.version = features.fw_version;
input->open = wacom_i2c_open;
input->close = wacom_i2c_close;
input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
__set_bit(BTN_TOOL_PEN, input->keybit);
__set_bit(BTN_TOOL_RUBBER, input->keybit);
__set_bit(BTN_STYLUS, input->keybit);
__set_bit(BTN_STYLUS2, input->keybit);
__set_bit(BTN_TOUCH, input->keybit);
input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0);
input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0);
input_set_abs_params(input, ABS_PRESSURE,
0, features.pressure_max, 0, 0);
input_set_drvdata(input, wac_i2c);
error = devm_request_threaded_irq(dev, client->irq, NULL, wacom_i2c_irq,
IRQF_ONESHOT, "wacom_i2c", wac_i2c);
if (error) {
dev_err(dev, "Failed to request IRQ: %d\n", error);
return error;
}
disable_irq(client->irq);
error = input_register_device(wac_i2c->input);
if (error) {
dev_err(dev, "Failed to register input device: %d\n", error);
return error;
}
return 0;
}
static int wacom_i2c_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
disable_irq(client->irq);
return 0;
}
static int wacom_i2c_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
enable_irq(client->irq);
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume);
static const struct i2c_device_id wacom_i2c_id[] = {
{ "WAC_I2C_EMR" },
{ }
};
MODULE_DEVICE_TABLE(i2c, wacom_i2c_id);
static struct i2c_driver wacom_i2c_driver = {
.driver = {
.name = "wacom_i2c",
.pm = pm_sleep_ptr(&wacom_i2c_pm),
},
.probe = wacom_i2c_probe,
.id_table = wacom_i2c_id,
};
module_i2c_driver(wacom_i2c_driver);
MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>");
MODULE_DESCRIPTION("WACOM EMR I2C Driver");
MODULE_LICENSE("GPL");
