// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for Pixcir I2C touchscreen controllers.
*
* Copyright (C) 2010-2011 Pixcir, Inc.
*/
#include <linux/unaligned.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.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/slab.h>
#define PIXCIR_MAX_SLOTS 5 /* Max fingers supported by driver */
/*
* Register map
*/
#define PIXCIR_REG_POWER_MODE 51
#define PIXCIR_REG_INT_MODE 52
/*
* Power modes:
* active: max scan speed
* idle: lower scan speed with automatic transition to active on touch
* halt: datasheet says sleep but this is more like halt as the chip
* clocks are cut and it can only be brought out of this mode
* using the RESET pin.
*/
enum pixcir_power_mode {
PIXCIR_POWER_ACTIVE,
PIXCIR_POWER_IDLE,
PIXCIR_POWER_HALT,
};
#define PIXCIR_POWER_MODE_MASK 0x03
#define PIXCIR_POWER_ALLOW_IDLE (1UL << 2)
/*
* Interrupt modes:
* periodical: interrupt is asserted periodicaly
* diff coordinates: interrupt is asserted when coordinates change
* level on touch: interrupt level asserted during touch
* pulse on touch: interrupt pulse asserted during touch
*
*/
enum pixcir_int_mode {
PIXCIR_INT_PERIODICAL,
PIXCIR_INT_DIFF_COORD,
PIXCIR_INT_LEVEL_TOUCH,
PIXCIR_INT_PULSE_TOUCH,
};
#define PIXCIR_INT_MODE_MASK 0x03
#define PIXCIR_INT_ENABLE (1UL << 3)
#define PIXCIR_INT_POL_HIGH (1UL << 2)
/**
* struct pixcir_i2c_chip_data - chip related data
* @max_fingers: Max number of fingers reported simultaneously by h/w
* @has_hw_ids: Hardware supports finger tracking IDs
*
*/
struct pixcir_i2c_chip_data {
u8 max_fingers;
bool has_hw_ids;
};
struct pixcir_i2c_ts_data {
struct i2c_client *client;
struct input_dev *input;
struct gpio_desc *gpio_attb;
struct gpio_desc *gpio_reset;
struct gpio_desc *gpio_enable;
struct gpio_desc *gpio_wake;
const struct pixcir_i2c_chip_data *chip;
struct touchscreen_properties prop;
bool running;
};
struct pixcir_report_data {
int num_touches;
struct input_mt_pos pos[PIXCIR_MAX_SLOTS];
int ids[PIXCIR_MAX_SLOTS];
};
static void pixcir_ts_parse(struct pixcir_i2c_ts_data *tsdata,
struct pixcir_report_data *report)
{
u8 rdbuf[2 + PIXCIR_MAX_SLOTS * 5];
u8 wrbuf[1] = { 0 };
u8 *bufptr;
u8 touch;
int ret, i;
int readsize;
const struct pixcir_i2c_chip_data *chip = tsdata->chip;
memset(report, 0, sizeof(struct pixcir_report_data));
i = chip->has_hw_ids ? 1 : 0;
readsize = 2 + tsdata->chip->max_fingers * (4 + i);
if (readsize > sizeof(rdbuf))
readsize = sizeof(rdbuf);
ret = i2c_master_send(tsdata->client, wrbuf, sizeof(wrbuf));
if (ret != sizeof(wrbuf)) {
dev_err(&tsdata->client->dev,
"%s: i2c_master_send failed(), ret=%d\n",
__func__, ret);
return;
}
ret = i2c_master_recv(tsdata->client, rdbuf, readsize);
if (ret != readsize) {
dev_err(&tsdata->client->dev,
"%s: i2c_master_recv failed(), ret=%d\n",
__func__, ret);
return;
}
touch = rdbuf[0] & 0x7;
if (touch > tsdata->chip->max_fingers)
touch = tsdata->chip->max_fingers;
report->num_touches = touch;
bufptr = &rdbuf[2];
for (i = 0; i < touch; i++) {
touchscreen_set_mt_pos(&report->pos[i], &tsdata->prop,
get_unaligned_le16(bufptr),
get_unaligned_le16(bufptr + 2));
if (chip->has_hw_ids) {
report->ids[i] = bufptr[4];
bufptr = bufptr + 5;
} else {
bufptr = bufptr + 4;
}
}
}
static void pixcir_ts_report(struct pixcir_i2c_ts_data *ts,
struct pixcir_report_data *report)
{
int slots[PIXCIR_MAX_SLOTS];
int n, i, slot;
struct device *dev = &ts->client->dev;
const struct pixcir_i2c_chip_data *chip = ts->chip;
n = report->num_touches;
if (n > PIXCIR_MAX_SLOTS)
n = PIXCIR_MAX_SLOTS;
if (!ts->chip->has_hw_ids)
input_mt_assign_slots(ts->input, slots, report->pos, n, 0);
for (i = 0; i < n; i++) {
if (chip->has_hw_ids) {
slot = input_mt_get_slot_by_key(ts->input,
report->ids[i]);
if (slot < 0) {
dev_dbg(dev, "no free slot for id 0x%x\n",
report->ids[i]);
continue;
}
} else {
slot = slots[i];
}
input_mt_slot(ts->input, slot);
input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
input_report_abs(ts->input, ABS_MT_POSITION_X,
report->pos[i].x);
input_report_abs(ts->input, ABS_MT_POSITION_Y,
report->pos[i].y);
dev_dbg(dev, "%d: slot %d, x %d, y %d\n",
i, slot, report->pos[i].x, report->pos[i].y);
}
input_mt_sync_frame(ts->input);
input_sync(ts->input);
}
static irqreturn_t pixcir_ts_isr(int irq, void *dev_id)
{
struct pixcir_i2c_ts_data *tsdata = dev_id;
struct pixcir_report_data report;
while (tsdata->running) {
/* parse packet */
pixcir_ts_parse(tsdata, &report);
/* report it */
pixcir_ts_report(tsdata, &report);
if (gpiod_get_value_cansleep(tsdata->gpio_attb)) {
if (report.num_touches) {
/*
* Last report with no finger up?
* Do it now then.
*/
input_mt_sync_frame(tsdata->input);
input_sync(tsdata->input);
}
break;
}
msleep(20);
}
return IRQ_HANDLED;
}
static void pixcir_reset(struct pixcir_i2c_ts_data *tsdata)
{
if (!IS_ERR_OR_NULL(tsdata->gpio_reset)) {
gpiod_set_value_cansleep(tsdata->gpio_reset, 1);
ndelay(100); /* datasheet section 1.2.3 says 80ns min. */
gpiod_set_value_cansleep(tsdata->gpio_reset, 0);
/* wait for controller ready. 100ms guess. */
msleep(100);
}
}
static int pixcir_set_power_mode(struct pixcir_i2c_ts_data *ts,
enum pixcir_power_mode mode)
{
struct device *dev = &ts->client->dev;
int ret;
if (mode == PIXCIR_POWER_ACTIVE || mode == PIXCIR_POWER_IDLE) {
if (ts->gpio_wake)
gpiod_set_value_cansleep(ts->gpio_wake, 1);
}
ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_POWER_MODE);
if (ret < 0) {
dev_err(dev, "%s: can't read reg %d : %d\n",
__func__, PIXCIR_REG_POWER_MODE, ret);
return ret;
}
ret &= ~PIXCIR_POWER_MODE_MASK;
ret |= mode;
/* Always AUTO_IDLE */
ret |= PIXCIR_POWER_ALLOW_IDLE;
ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_POWER_MODE, ret);
if (ret < 0) {
dev_err(dev, "%s: can't write reg %d : %d\n",
__func__, PIXCIR_REG_POWER_MODE, ret);
return ret;
}
if (mode == PIXCIR_POWER_HALT) {
if (ts->gpio_wake)
gpiod_set_value_cansleep(ts->gpio_wake, 0);
}
return 0;
}
/*
* Set the interrupt mode for the device i.e. ATTB line behaviour
*
* @polarity : 1 for active high, 0 for active low.
*/
static int pixcir_set_int_mode(struct pixcir_i2c_ts_data *ts,
enum pixcir_int_mode mode, bool polarity)
{
struct device *dev = &ts->client->dev;
int ret;
ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
if (ret < 0) {
dev_err(dev, "%s: can't read reg %d : %d\n",
__func__, PIXCIR_REG_INT_MODE, ret);
return ret;
}
ret &= ~PIXCIR_INT_MODE_MASK;
ret |= mode;
if (polarity)
ret |= PIXCIR_INT_POL_HIGH;
else
ret &= ~PIXCIR_INT_POL_HIGH;
ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
if (ret < 0) {
dev_err(dev, "%s: can't write reg %d : %d\n",
__func__, PIXCIR_REG_INT_MODE, ret);
return ret;
}
return 0;
}
/*
* Enable/disable interrupt generation
*/
static int pixcir_int_enable(struct pixcir_i2c_ts_data *ts, bool enable)
{
struct device *dev = &ts->client->dev;
int ret;
ret = i2c_smbus_read_byte_data(ts->client, PIXCIR_REG_INT_MODE);
if (ret < 0) {
dev_err(dev, "%s: can't read reg %d : %d\n",
__func__, PIXCIR_REG_INT_MODE, ret);
return ret;
}
if (enable)
ret |= PIXCIR_INT_ENABLE;
else
ret &= ~PIXCIR_INT_ENABLE;
ret = i2c_smbus_write_byte_data(ts->client, PIXCIR_REG_INT_MODE, ret);
if (ret < 0) {
dev_err(dev, "%s: can't write reg %d : %d\n",
__func__, PIXCIR_REG_INT_MODE, ret);
return ret;
}
return 0;
}
static int pixcir_start(struct pixcir_i2c_ts_data *ts)
{
struct device *dev = &ts->client->dev;
int error;
if (ts->gpio_enable) {
gpiod_set_value_cansleep(ts->gpio_enable, 1);
msleep(100);
}
/* LEVEL_TOUCH interrupt with active low polarity */
error = pixcir_set_int_mode(ts, PIXCIR_INT_LEVEL_TOUCH, 0);
if (error) {
dev_err(dev, "Failed to set interrupt mode: %d\n", error);
return error;
}
ts->running = true;
mb(); /* Update status before IRQ can fire */
/* enable interrupt generation */
error = pixcir_int_enable(ts, true);
if (error) {
dev_err(dev, "Failed to enable interrupt generation: %d\n",
error);
return error;
}
return 0;
}
static int pixcir_stop(struct pixcir_i2c_ts_data *ts)
{
int error;
/* Disable interrupt generation */
error = pixcir_int_enable(ts, false);
if (error) {
dev_err(&ts->client->dev,
"Failed to disable interrupt generation: %d\n",
error);
return error;
}
/* Exit ISR if running, no more report parsing */
ts->running = false;
mb(); /* update status before we synchronize irq */
/* Wait till running ISR is complete */
synchronize_irq(ts->client->irq);
if (ts->gpio_enable)
gpiod_set_value_cansleep(ts->gpio_enable, 0);
return 0;
}
static int pixcir_input_open(struct input_dev *dev)
{
struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
return pixcir_start(ts);
}
static void pixcir_input_close(struct input_dev *dev)
{
struct pixcir_i2c_ts_data *ts = input_get_drvdata(dev);
pixcir_stop(ts);
}
static int pixcir_i2c_ts_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
struct input_dev *input = ts->input;
int ret = 0;
mutex_lock(&input->mutex);
if (device_may_wakeup(&client->dev)) {
if (!input_device_enabled(input)) {
ret = pixcir_start(ts);
if (ret) {
dev_err(dev, "Failed to start\n");
goto unlock;
}
}
} else if (input_device_enabled(input)) {
ret = pixcir_stop(ts);
}
unlock:
mutex_unlock(&input->mutex);
return ret;
}
static int pixcir_i2c_ts_resume(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct pixcir_i2c_ts_data *ts = i2c_get_clientdata(client);
struct input_dev *input = ts->input;
int ret = 0;
mutex_lock(&input->mutex);
if (device_may_wakeup(&client->dev)) {
if (!input_device_enabled(input)) {
ret = pixcir_stop(ts);
if (ret) {
dev_err(dev, "Failed to stop\n");
goto unlock;
}
}
} else if (input_device_enabled(input)) {
ret = pixcir_start(ts);
}
unlock:
mutex_unlock(&input->mutex);
return ret;
}
static DEFINE_SIMPLE_DEV_PM_OPS(pixcir_dev_pm_ops,
pixcir_i2c_ts_suspend, pixcir_i2c_ts_resume);
static int pixcir_i2c_ts_probe(struct i2c_client *client)
{
const struct i2c_device_id *id = i2c_client_get_device_id(client);
struct device *dev = &client->dev;
struct pixcir_i2c_ts_data *tsdata;
struct input_dev *input;
int error;
tsdata = devm_kzalloc(dev, sizeof(*tsdata), GFP_KERNEL);
if (!tsdata)
return -ENOMEM;
tsdata->chip = device_get_match_data(dev);
if (!tsdata->chip && id)
tsdata->chip = (const void *)id->driver_data;
if (!tsdata->chip) {
dev_err(dev, "can't locate chip data\n");
return -EINVAL;
}
input = devm_input_allocate_device(dev);
if (!input) {
dev_err(dev, "Failed to allocate input device\n");
return -ENOMEM;
}
tsdata->client = client;
tsdata->input = input;
input->name = client->name;
input->id.bustype = BUS_I2C;
input->open = pixcir_input_open;
input->close = pixcir_input_close;
input_set_capability(input, EV_ABS, ABS_MT_POSITION_X);
input_set_capability(input, EV_ABS, ABS_MT_POSITION_Y);
touchscreen_parse_properties(input, true, &tsdata->prop);
if (!input_abs_get_max(input, ABS_MT_POSITION_X) ||
!input_abs_get_max(input, ABS_MT_POSITION_Y)) {
dev_err(dev, "Touchscreen size is not specified\n");
return -EINVAL;
}
error = input_mt_init_slots(input, tsdata->chip->max_fingers,
INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
if (error) {
dev_err(dev, "Error initializing Multi-Touch slots\n");
return error;
}
input_set_drvdata(input, tsdata);
tsdata->gpio_attb = devm_gpiod_get(dev, "attb", GPIOD_IN);
if (IS_ERR(tsdata->gpio_attb))
return dev_err_probe(dev, PTR_ERR(tsdata->gpio_attb),
"Failed to request ATTB gpio\n");
tsdata->gpio_reset = devm_gpiod_get_optional(dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(tsdata->gpio_reset))
return dev_err_probe(dev, PTR_ERR(tsdata->gpio_reset),
"Failed to request RESET gpio\n");
tsdata->gpio_wake = devm_gpiod_get_optional(dev, "wake",
GPIOD_OUT_HIGH);
if (IS_ERR(tsdata->gpio_wake))
return dev_err_probe(dev, PTR_ERR(tsdata->gpio_wake),
"Failed to get wake gpio\n");
tsdata->gpio_enable = devm_gpiod_get_optional(dev, "enable",
GPIOD_OUT_HIGH);
if (IS_ERR(tsdata->gpio_enable))
return dev_err_probe(dev, PTR_ERR(tsdata->gpio_enable),
"Failed to get enable gpio\n");
if (tsdata->gpio_enable)
msleep(100);
error = devm_request_threaded_irq(dev, client->irq, NULL, pixcir_ts_isr,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
client->name, tsdata);
if (error) {
dev_err(dev, "failed to request irq %d\n", client->irq);
return error;
}
pixcir_reset(tsdata);
/* Always be in IDLE mode to save power, device supports auto wake */
error = pixcir_set_power_mode(tsdata, PIXCIR_POWER_IDLE);
if (error) {
dev_err(dev, "Failed to set IDLE mode\n");
return error;
}
/* Stop device till opened */
error = pixcir_stop(tsdata);
if (error)
return error;
error = input_register_device(input);
if (error)
return error;
i2c_set_clientdata(client, tsdata);
return 0;
}
static const struct pixcir_i2c_chip_data pixcir_ts_data = {
.max_fingers = 2,
/* no hw id support */
};
static const struct pixcir_i2c_chip_data pixcir_tangoc_data = {
.max_fingers = 5,
.has_hw_ids = true,
};
static const struct i2c_device_id pixcir_i2c_ts_id[] = {
{ "pixcir_ts", (unsigned long) &pixcir_ts_data },
{ "pixcir_tangoc", (unsigned long) &pixcir_tangoc_data },
{ }
};
MODULE_DEVICE_TABLE(i2c, pixcir_i2c_ts_id);
#ifdef CONFIG_OF
static const struct of_device_id pixcir_of_match[] = {
{ .compatible = "pixcir,pixcir_ts", .data = &pixcir_ts_data },
{ .compatible = "pixcir,pixcir_tangoc", .data = &pixcir_tangoc_data },
{ }
};
MODULE_DEVICE_TABLE(of, pixcir_of_match);
#endif
static struct i2c_driver pixcir_i2c_ts_driver = {
.driver = {
.name = "pixcir_ts",
.pm = pm_sleep_ptr(&pixcir_dev_pm_ops),
.of_match_table = of_match_ptr(pixcir_of_match),
},
.probe = pixcir_i2c_ts_probe,
.id_table = pixcir_i2c_ts_id,
};
module_i2c_driver(pixcir_i2c_ts_driver);
MODULE_AUTHOR("Jianchun Bian <[email protected]>, Dequan Meng <[email protected]>");
MODULE_DESCRIPTION("Pixcir I2C Touchscreen Driver");
MODULE_LICENSE("GPL");
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