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#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/input/ili210x.h>
#define MAX_TOUCHES 2
#define DEFAULT_POLL_PERIOD 20
/* Touchscreen commands */
#define REG_TOUCHDATA 0x10
#define REG_PANEL_INFO 0x20
#define REG_FIRMWARE_VERSION 0x40
#define REG_CALIBRATE 0xcc
struct finger {
u8 x_low;
u8 x_high;
u8 y_low;
u8 y_high;
} __packed;
struct touchdata {
u8 status;
struct finger finger[MAX_TOUCHES];
} __packed;
struct panel_info {
struct finger finger_max;
u8 xchannel_num;
u8 ychannel_num;
} __packed;
struct firmware_version {
u8 id;
u8 major;
u8 minor;
} __packed;
struct ili210x {
struct i2c_client *client;
struct input_dev *input;
bool (*get_pendown_state)(void);
unsigned int poll_period;
struct delayed_work dwork;
};
static int ili210x_read_reg(struct i2c_client *client, u8 reg, void *buf,
size_t len)
{
struct i2c_msg msg[2] = {
{
.addr = client->addr,
.flags = 0,
.len = 1,
.buf = ®,
},
{
.addr = client->addr,
.flags = I2C_M_RD,
.len = len,
.buf = buf,
}
};
if (i2c_transfer(client->adapter, msg, 2) != 2) {
dev_err(&client->dev, "i2c transfer failed\n");
return -EIO;
}
return 0;
}
static void ili210x_report_events(struct input_dev *input,
const struct touchdata *touchdata)
{
int i;
bool touch;
unsigned int x, y;
const struct finger *finger;
for (i = 0; i < MAX_TOUCHES; i++) {
input_mt_slot(input, i);
finger = &touchdata->finger[i];
touch = touchdata->status & (1 << i);
input_mt_report_slot_state(input, MT_TOOL_FINGER, touch);
if (touch) {
x = finger->x_low | (finger->x_high << 8);
y = finger->y_low | (finger->y_high << 8);
input_report_abs(input, ABS_MT_POSITION_X, x);
input_report_abs(input, ABS_MT_POSITION_Y, y);
}
}
input_mt_report_pointer_emulation(input, false);
input_sync(input);
}
static bool get_pendown_state(const struct ili210x *priv)
{
bool state = false;
if (priv->get_pendown_state)
state = priv->get_pendown_state();
return state;
}
static void ili210x_work(struct work_struct *work)
{
struct ili210x *priv = container_of(work, struct ili210x,
dwork.work);
struct i2c_client *client = priv->client;
struct touchdata touchdata;
int error;
error = ili210x_read_reg(client, REG_TOUCHDATA,
&touchdata, sizeof(touchdata));
if (error) {
dev_err(&client->dev,
"Unable to get touchdata, err = %d\n", error);
return;
}
ili210x_report_events(priv->input, &touchdata);
if ((touchdata.status & 0xf3) || get_pendown_state(priv))
schedule_delayed_work(&priv->dwork,
msecs_to_jiffies(priv->poll_period));
}
static irqreturn_t ili210x_irq(int irq, void *irq_data)
{
struct ili210x *priv = irq_data;
schedule_delayed_work(&priv->dwork, 0);
return IRQ_HANDLED;
}
static ssize_t ili210x_calibrate(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
struct ili210x *priv = i2c_get_clientdata(client);
unsigned long calibrate;
int rc;
u8 cmd = REG_CALIBRATE;
if (kstrtoul(buf, 10, &calibrate))
return -EINVAL;
if (calibrate > 1)
return -EINVAL;
if (calibrate) {
rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
if (rc != sizeof(cmd))
return -EIO;
}
return count;
}
static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
static struct attribute *ili210x_attributes[] = {
&dev_attr_calibrate.attr,
NULL,
};
static const struct attribute_group ili210x_attr_group = {
.attrs = ili210x_attributes,
};
static int ili210x_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
const struct ili210x_platform_data *pdata = dev_get_platdata(dev);
struct ili210x *priv;
struct input_dev *input;
struct panel_info panel;
struct firmware_version firmware;
int xmax, ymax;
int error;
dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
if (!pdata) {
dev_err(dev, "No platform data!\n");
return -EINVAL;
}
if (client->irq <= 0) {
dev_err(dev, "No IRQ!\n");
return -EINVAL;
}
/* Get firmware version */
error = ili210x_read_reg(client, REG_FIRMWARE_VERSION,
&firmware, sizeof(firmware));
if (error) {
dev_err(dev, "Failed to get firmware version, err: %d\n",
error);
return error;
}
/* get panel info */
error = ili210x_read_reg(client, REG_PANEL_INFO, &panel, sizeof(panel));
if (error) {
dev_err(dev, "Failed to get panel information, err: %d\n",
error);
return error;
}
xmax = panel.finger_max.x_low | (panel.finger_max.x_high << 8);
ymax = panel.finger_max.y_low | (panel.finger_max.y_high << 8);
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
input = input_allocate_device();
if (!priv || !input) {
error = -ENOMEM;
goto err_free_mem;
}
priv->client = client;
priv->input = input;
priv->get_pendown_state = pdata->get_pendown_state;
priv->poll_period = pdata->poll_period ? : DEFAULT_POLL_PERIOD;
INIT_DELAYED_WORK(&priv->dwork, ili210x_work);
/* Setup input device */
input->name = "ILI210x Touchscreen";
input->id.bustype = BUS_I2C;
input->dev.parent = dev;
__set_bit(EV_SYN, input->evbit);
__set_bit(EV_KEY, input->evbit);
__set_bit(EV_ABS, input->evbit);
__set_bit(BTN_TOUCH, input->keybit);
/* Single touch */
input_set_abs_params(input, ABS_X, 0, xmax, 0, 0);
input_set_abs_params(input, ABS_Y, 0, ymax, 0, 0);
/* Multi touch */
input_mt_init_slots(input, MAX_TOUCHES, 0);
input_set_abs_params(input, ABS_MT_POSITION_X, 0, xmax, 0, 0);
input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ymax, 0, 0);
i2c_set_clientdata(client, priv);
error = request_irq(client->irq, ili210x_irq
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