#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
#define IST30XX_REG_STATUS 0x20
#define IST30XX_REG_CHIPID (0x40000000 | IST3038C_DIRECT_ACCESS)
#define IST30XX_WHOAMI 0x30003000
#define IST30XXA_WHOAMI 0x300a300a
#define IST30XXB_WHOAMI 0x300b300b
#define IST3038_WHOAMI 0x30383038
#define IST3032C_WHOAMI 0x32c
#define IST3038C_WHOAMI 0x38c
#define IST3038H_WHOAMI 0x38d
#define IST3038B_REG_CHIPID 0x30
#define IST3038B_WHOAMI 0x30380b
#define IST3038C_HIB_ACCESS (0x800B << 16)
#define IST3038C_DIRECT_ACCESS BIT(31)
#define IST3038C_REG_CHIPID (0x40001000 | IST3038C_DIRECT_ACCESS)
#define IST3038C_REG_HIB_BASE 0x30000100
#define IST3038C_REG_TOUCH_STATUS (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS)
#define IST3038C_REG_TOUCH_COORD (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x8)
#define IST3038C_REG_INTR_MESSAGE (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x4)
#define IST3038C_CHIP_ON_DELAY_MS 60
#define IST3038C_I2C_RETRY_COUNT 3
#define IST3038C_MAX_FINGER_NUM 10
#define IST3038C_X_MASK GENMASK(23, 12)
#define IST3038C_Y_MASK GENMASK(11, 0)
#define IST3038C_AREA_MASK GENMASK(27, 24)
#define IST3038C_FINGER_COUNT_MASK GENMASK(15, 12)
#define IST3038C_FINGER_STATUS_MASK GENMASK(9, 0)
#define IST3032C_KEY_STATUS_MASK GENMASK(20, 16)
struct imagis_properties {
unsigned int interrupt_msg_cmd;
unsigned int touch_coord_cmd;
unsigned int whoami_cmd;
unsigned int whoami_val;
bool protocol_b;
bool touch_keys_supported;
};
struct imagis_ts {
struct i2c_client *client;
const struct imagis_properties *tdata;
struct input_dev *input_dev;
struct touchscreen_properties prop;
struct regulator_bulk_data supplies[2];
u32 keycodes[5];
int num_keycodes;
};
static int imagis_i2c_read_reg(struct imagis_ts *ts,
unsigned int reg, u32 *data)
{
__be32 ret_be;
__be32 reg_be = cpu_to_be32(reg);
struct i2c_msg msg[] = {
{
.addr = ts->client->addr,
.flags = 0,
.buf = (unsigned char *)®_be,
.len = sizeof(reg_be),
}, {
.addr = ts->client->addr,
.flags = I2C_M_RD,
.buf = (unsigned char *)&ret_be,
.len = sizeof(ret_be),
},
};
int ret, error;
int retry = IST3038C_I2C_RETRY_COUNT;
do {
ret = i2c_transfer(ts->client->adapter, msg, ARRAY_SIZE(msg));
if (ret == ARRAY_SIZE(msg)) {
*data = be32_to_cpu(ret_be);
return 0;
}
error = ret < 0 ? ret : -EIO;
dev_err(&ts->client->dev,
"%s - i2c_transfer failed: %d (%d)\n",
__func__, error, ret);
} while (--retry);
return error;
}
static irqreturn_t imagis_interrupt(int irq, void *dev_id)
{
struct imagis_ts *ts = dev_id;
u32 intr_message, finger_status;
unsigned int finger_count, finger_pressed, key_pressed;
int i;
int error;
error = imagis_i2c_read_reg(ts, ts->tdata->interrupt_msg_cmd, &intr_message);
if (error) {
dev_err(&ts->client->dev,
"failed to read the interrupt message: %d\n", error);
goto out;
}
finger_count = FIELD_GET(IST3038C_FINGER_COUNT_MASK, intr_message);
if (finger_count > IST3038C_MAX_FINGER_NUM) {
dev_err(&ts->client->dev,
"finger count %d is more than maximum supported\n",
finger_count);
goto out;
}
finger_pressed = FIELD_GET(IST3038C_FINGER_STATUS_MASK, intr_message);
for (i = 0; i < finger_count; i++) {
if (ts->tdata->protocol_b)
error = imagis_i2c_read_reg(ts,
ts->tdata->touch_coord_cmd + (i * 4),
&finger_status);
else
error = imagis_i2c_read_reg(ts,
ts->tdata->touch_coord_cmd, &finger_status);
if (error) {
dev_err(&ts->client->dev,
"failed to read coordinates for finger %d: %d\n",
i, error);
goto out;
}
input_mt_slot(ts->input_dev, i);
input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER,
finger_pressed & BIT(i));
touchscreen_report_pos(ts->input_dev, &ts->prop,
FIELD_GET(IST3038C_X_MASK, finger_status),
FIELD_GET(IST3038C_Y_MASK, finger_status),
true);
input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR,
FIELD_GET(IST3038C_AREA_MASK, finger_status));
}
key_pressed = FIELD_GET(IST3032C_KEY_STATUS_MASK, intr_message);
for (int i = 0; i < ts->num_keycodes; i++)
input_report_key(ts->input_dev, ts->keycodes[i],
key_pressed & BIT(i));
input_mt_sync_frame(ts->input_dev);
input_sync(ts->input_dev);
out:
return IRQ_HANDLED;
}
static void imagis_power_off(void *_ts)
{
struct imagis_ts *ts = _ts;
regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
}
static int imagis_power_on(struct imagis_ts *ts)
{
int error;
error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
if (error)
return error;
msleep(IST3038C_CHIP_ON_DELAY_MS);
return 0;
}
static int imagis_start(struct imagis_ts *ts)
{
int error;
error = imagis_power_on(ts);
if (error)
return error;
enable_irq(ts->client->irq);
return 0;
}
static int imagis_stop(struct imagis_ts *ts)
{
disable_irq(ts->client->irq);
imagis_power_off(ts);
return 0;
}
static int imagis_input_open(struct input_dev *dev)
{
struct imagis_ts *ts = input_get_drvdata(dev);
return imagis_start(ts);
}
static void imagis_input_close(struct input_dev *dev)
{
struct imagis_ts *ts = input_get_drvdata(dev);
imagis_stop(ts);
}
static int imagis_init_input_dev(struct imagis_ts *ts)
{
struct input_dev *input_dev;
int error;
input_dev = devm_input_allocate_device(&ts->client->dev);
if (!input_dev)
return -ENOMEM;
ts->input_dev = input_dev;
input_dev->name = "Imagis capacitive touchscreen";
input_dev->phys = "input/ts";
input_dev->id.bustype = BUS_I2C;
input_dev->open = imagis_input_open;
input_dev->close = imagis_input_close;
input_set_drvdata(input_dev, ts);
input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 16, 0, 0);
if (ts->tdata->touch_keys_supported) {
ts->num_keycodes = of_property_read_variable_u32_array(
ts->client->dev.of_node, "linux,keycodes",
ts->keycodes, 0, ARRAY_SIZE(ts->keycodes));
if (ts->num_keycodes <= 0) {
ts->keycodes[0] = KEY_APPSELECT;
ts->keycodes[1] = KEY_BACK;
ts->num_keycodes = 2;
}
input_dev->keycodemax = ts->num_keycodes;
input_dev->keycodesize = sizeof(ts->keycodes[0]);
input_dev->keycode = ts->keycodes;
}
for (int i = 0; i < ts->num_keycodes; i++)
input_set_capability(input_dev, EV_KEY, ts->keycodes[i]);
touchscreen_parse_properties(input_dev, true, &ts->prop);
if (!ts->prop.max_x || !ts->prop.max_y) {
dev_err(&ts->client->dev,
"Touchscreen-size-x and/or touchscreen-size-y not set in dts\n");
return -EINVAL;
}
error = input_mt_init_slots(input_dev,
IST3038C_MAX_FINGER_NUM,
INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
if (error) {
dev_err(&ts->client->dev,
"Failed to initialize MT slots: %d", error);
return error;
}
error = input_register_device(input_dev);
if (error) {
dev_err(&ts->client->dev,
"Failed to register input device: %d", error);
return error;
}
return 0;
}
static int imagis_init_regulators(struct imagis_ts *ts)
{
struct i2c_client *client = ts->client;
ts->supplies[0].supply = "vdd";
ts->supplies[1].supply = "vddio";
return devm_regulator_bulk_get(&client->dev,
ARRAY_SIZE(ts->supplies),
ts->supplies);
}
static int imagis_probe(struct i2c_client *i2c)
{
struct device *dev = &i2c->dev;
struct imagis_ts *ts;
int chip_id, error;
ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
if (!ts)
return -ENOMEM;
ts->client = i2c;
ts->tdata = device_get_match_data(dev);
if (!ts->tdata) {
dev_err(dev, "missing chip data\n");
return -EINVAL;
}
error = imagis_init_regulators(ts);
if (error) {
dev_err(dev, "regulator init error: %d\n", error);
return error;
}
error = imagis_power_on(ts);
if (error) {
dev_err(dev, "failed to enable regulators: %d\n", error);
return error;
}
error = devm_add_action_or_reset(dev, imagis_power_off, ts);
if (error) {
dev_err(dev, "failed to install poweroff action: %d\n", error);
return error;
}
error = imagis_i2c_read_reg(ts, ts->tdata->whoami_cmd, &chip_id);
if (error) {
dev_err(dev, "chip ID read failure: %d\n", error);
return error;
}
if (chip_id != ts->tdata->whoami_val) {
dev_err(dev, "unknown chip ID: 0x%x\n", chip_id);
return -EINVAL;
}
error = devm_request_threaded_irq(dev, i2c->irq,
NULL, imagis_interrupt,
IRQF_ONESHOT | IRQF_NO_AUTOEN,
"imagis-touchscreen", ts);
if (error) {
dev_err(dev, "IRQ %d allocation failure: %d\n",
i2c->irq, error);
return error;
}
error = imagis_init_input_dev(ts);
if (error)
return error;
return 0;
}
static int imagis_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct imagis_ts *ts = i2c_get_clientdata(client);
int retval = 0;
mutex_lock(&ts->input_dev->mutex);
if (input_device_enabled(ts->input_dev))
retval = imagis_stop(ts);
mutex_unlock(&ts->input_dev->mutex);
return retval;
}
static int imagis_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct imagis_ts *ts = i2c_get_clientdata(client);
int retval = 0;
mutex_lock(&ts->input_dev->mutex);
if (input_device_enabled(ts->input_dev))
retval = imagis_start(ts);
mutex_unlock(&ts->input_dev->mutex);
return retval;
}
static DEFINE_SIMPLE_DEV_PM_OPS(imagis_pm_ops, imagis_suspend, imagis_resume);
#ifdef CONFIG_OF
static const struct imagis_properties imagis_3032c_data = {
.interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
.touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
.whoami_cmd = IST3038C_REG_CHIPID,
.whoami_val = IST3032C_WHOAMI,
.touch_keys_supported = true,
.protocol_b = true,
};
static const struct imagis_properties imagis_3038_data = {
.interrupt_msg_cmd = IST30XX_REG_STATUS,
.touch_coord_cmd = IST30XX_REG_STATUS,
.whoami_cmd = IST30XX_REG_CHIPID,
.whoami_val = IST3038_WHOAMI,
.touch_keys_supported = true,
};
static const struct imagis_properties imagis_3038b_data = {
.interrupt_msg_cmd = IST30XX_REG_STATUS,
.touch_coord_cmd = IST30XX_REG_STATUS,
.whoami_cmd = IST3038B_REG_CHIPID,
.whoami_val = IST3038B_WHOAMI,
};
static const struct imagis_properties imagis_3038c_data = {
.interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
.touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
.whoami_cmd = IST3038C_REG_CHIPID,
.whoami_val = IST3038C_WHOAMI,
.protocol_b = true,
};
static const struct imagis_properties imagis_3038h_data = {
.interrupt_msg_cmd = IST3038C_REG_INTR_MESSAGE,
.touch_coord_cmd = IST3038C_REG_TOUCH_COORD,
.whoami_cmd = IST3038C_REG_CHIPID,
.whoami_val = IST3038H_WHOAMI,
};
static const struct of_device_id imagis_of_match[] = {
{ .compatible = "imagis,ist3032c", .data = &imagis_3032c_data },
{ .compatible = "imagis,ist3038", .data = &imagis_3038_data },
{ .compatible = "imagis,ist3038b", .data = &imagis_3038b_data },
{ .compatible = "imagis,ist3038c", .data = &imagis_3038c_data },
{ .compatible = "imagis,ist3038h", .data = &imagis_3038h_data },
{ },
};
MODULE_DEVICE_TABLE(of, imagis_of_match);
#endif
static struct i2c_driver imagis_ts_driver = {
.driver = {
.name = "imagis-touchscreen",
.pm = pm_sleep_ptr(&imagis_pm_ops),
.of_match_table = of_match_ptr(imagis_of_match),
},
.probe = imagis_probe,
};
module_i2c_driver(imagis_ts_driver);
MODULE_DESCRIPTION("Imagis IST3038C Touchscreen Driver");
MODULE_AUTHOR("Markuss Broks <markuss.broks@gmail.com>");
MODULE_LICENSE("GPL");
