// SPDX-License-Identifier: GPL-2.0 // STMicroelectronics FTS Touchscreen device driver // // Copyright (c) 2017 Samsung Electronics Co., Ltd. // Copyright (c) 2017 Andi Shyti #include #include #include #include #include #include #include #include #include #include /* I2C commands */ #define STMFTS_READ_INFO 0x80 #define STMFTS_READ_STATUS 0x84 #define STMFTS_READ_ONE_EVENT 0x85 #define STMFTS_READ_ALL_EVENT 0x86 #define STMFTS_LATEST_EVENT 0x87 #define STMFTS_SLEEP_IN 0x90 #define STMFTS_SLEEP_OUT 0x91 #define STMFTS_MS_MT_SENSE_OFF 0x92 #define STMFTS_MS_MT_SENSE_ON 0x93 #define STMFTS_SS_HOVER_SENSE_OFF 0x94 #define STMFTS_SS_HOVER_SENSE_ON 0x95 #define STMFTS_MS_KEY_SENSE_OFF 0x9a #define STMFTS_MS_KEY_SENSE_ON 0x9b #define STMFTS_SYSTEM_RESET 0xa0 #define STMFTS_CLEAR_EVENT_STACK 0xa1 #define STMFTS_FULL_FORCE_CALIBRATION 0xa2 #define STMFTS_MS_CX_TUNING 0xa3 #define STMFTS_SS_CX_TUNING 0xa4 /* events */ #define STMFTS_EV_NO_EVENT 0x00 #define STMFTS_EV_MULTI_TOUCH_DETECTED 0x02 #define STMFTS_EV_MULTI_TOUCH_ENTER 0x03 #define STMFTS_EV_MULTI_TOUCH_LEAVE 0x04 #define STMFTS_EV_MULTI_TOUCH_MOTION 0x05 #define STMFTS_EV_HOVER_ENTER 0x07 #define STMFTS_EV_HOVER_LEAVE 0x08 #define STMFTS_EV_HOVER_MOTION 0x09 #define STMFTS_EV_KEY_STATUS 0x0e #define STMFTS_EV_ERROR 0x0f #define STMFTS_EV_CONTROLLER_READY 0x10 #define STMFTS_EV_SLEEP_OUT_CONTROLLER_READY 0x11 #define STMFTS_EV_STATUS 0x16 #define STMFTS_EV_DEBUG 0xdb /* multi touch related event masks */ #define STMFTS_MASK_EVENT_ID 0x0f #define STMFTS_MASK_TOUCH_ID 0xf0 #define STMFTS_MASK_LEFT_EVENT 0x0f #define STMFTS_MASK_X_MSB 0x0f #define STMFTS_MASK_Y_LSB 0xf0 /* key related event masks */ #define STMFTS_MASK_KEY_NO_TOUCH 0x00 #define STMFTS_MASK_KEY_MENU 0x01 #define STMFTS_MASK_KEY_BACK 0x02 #define STMFTS_EVENT_SIZE 8 #define STMFTS_STACK_DEPTH 32 #define STMFTS_DATA_MAX_SIZE (STMFTS_EVENT_SIZE * STMFTS_STACK_DEPTH) #define STMFTS_MAX_FINGERS 10 #define STMFTS_DEV_NAME "stmfts" enum stmfts_regulators { STMFTS_REGULATOR_VDD, STMFTS_REGULATOR_AVDD, }; struct stmfts_data { struct i2c_client *client; struct input_dev *input; struct led_classdev led_cdev; struct mutex mutex; struct touchscreen_properties prop; struct regulator_bulk_data regulators[2]; /* * Presence of ledvdd will be used also to check * whether the LED is supported. */ struct regulator *ledvdd; u16 chip_id; u8 chip_ver; u16 fw_ver; u8 config_id; u8 config_ver; u8 data[STMFTS_DATA_MAX_SIZE]; struct completion cmd_done; bool use_key; bool led_status; bool hover_enabled; bool running; }; static int stmfts_brightness_set(struct led_classdev *led_cdev, enum led_brightness value) { struct stmfts_data *sdata = container_of(led_cdev, struct stmfts_data, led_cdev); int err; if (value != sdata->led_status && sdata->ledvdd) { if (!value) { regulator_disable(sdata->ledvdd); } else { err = regulator_enable(sdata->ledvdd); if (err) { dev_warn(&sdata->client->dev, "failed to disable ledvdd regulator: %d\n", err); return err; } } sdata->led_status = value; } return 0; } static enum led_brightness stmfts_brightness_get(struct led_classdev *led_cdev) { struct stmfts_data *sdata = container_of(led_cdev, struct stmfts_data, led_cdev); return !!regulator_is_enabled(sdata->ledvdd); } /* * We can't simply use i2c_smbus_read_i2c_block_data because we * need to read more than 255 bytes ( */ static int stmfts_read_events(struct stmfts_data *sdata) { u8 cmd = STMFTS_READ_ALL_EVENT; struct i2c_msg msgs[2] = { { .addr = sdata->client->addr, .len = 1, .buf = &cmd, }, { .addr = sdata->client->addr, .flags = I2C_M_RD, .len = STMFTS_DATA_MAX_SIZE, .buf = sdata->data, }, }; int ret; ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs)); if (ret < 0) return ret; return ret == ARRAY_SIZE(msgs) ? 0 : -EIO; } static void stmfts_report_contact_event(struct stmfts_data *sdata, const u8 event[]) { u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4; u16 x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8); u16 y = (event[2] >> 4) | (event[3] << 4); u8 maj = event[4]; u8 min = event[5]; u8 orientation = event[6]; u8 area = event[7]; input_mt_slot(sdata->input, slot_id); input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true); input_report_abs(sdata->input, ABS_MT_POSITION_X, x); input_report_abs(sdata->input, ABS_MT_POSITION_Y, y); input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, maj); input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, min); input_report_abs(sdata->input, ABS_MT_PRESSURE, area); input_report_abs(sdata->input, ABS_MT_ORIENTATION, orientation); input_sync(sdata->input); } static void stmfts_report_contact_release(struct stmfts_data *sdata, const u8 event[]) { u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4; input_mt_slot(sdata->input, slot_id); input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, false); input_sync(sdata->input); } static void stmfts_report_hover_event(struct stmfts_data *sdata, const u8 event[]) { u16 x = (event[2] << 4) | (event[4] >> 4); u16 y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB); u8 z = event[5]; input_report_abs(sdata->input, ABS_X, x); input_report_abs(sdata->input, ABS_Y, y); input_report_abs(sdata->input, ABS_DISTANCE, z); input_sync(sdata->input); } static void stmfts_report_key_event(struct stmfts_data *sdata, const u8 event[]) { switch (event[2]) { case 0: input_report_key(sdata->input, KEY_BACK, 0); input_report_key(sdata->input, KEY_MENU, 0); break; case STMFTS_MASK_KEY_BACK: input_report_key(sdata->input, KEY_BACK, 1); break; case STMFTS_MASK_KEY_MENU: input_report_key(sdata->input, KEY_MENU, 1); break; default: dev_warn(&sdata->client->dev, "unknown key event: %#02x\n", event[2]); break; } input_sync(sdata->input); } static void stmfts_parse_events(struct stmfts_data *sdata) { int i; for (i = 0; i < STMFTS_STACK_DEPTH; i++) { u8 *event = &sdata->data[i * STMFTS_EVENT_SIZE]; switch (event[0]) { case STMFTS_EV_CONTROLLER_READY: case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY: case STMFTS_EV_STATUS: complete(&sdata->cmd_done); /* fall through */ case STMFTS_EV_NO_EVENT: case STMFTS_EV_DEBUG: return; } switch (event[0] & STMFTS_MASK_EVENT_ID) { case STMFTS_EV_MULTI_TOUCH_ENTER: case STMFTS_EV_MULTI_TOUCH_MOTION: stmfts_report_contact_event(sdata, event); break; case STMFTS_EV_MULTI_TOUCH_LEAVE: stmfts_report_contact_release(sdata, event); break; case STMFTS_EV_HOVER_ENTER: case STMFTS_EV_HOVER_LEAVE: case STMFTS_EV_HOVER_MOTION: stmfts_report_hover_event(sdata, event); break; case STMFTS_EV_KEY_STATUS: stmfts_report_key_event(sdata, event); break; case STMFTS_EV_ERROR: dev_warn(&sdata->client->dev, "error code: 0x%x%x%x%x%x%x", event[6], event[5], event[4], event[3], event[2], event[1]); break; default: dev_err(&sdata->client->dev, "unknown event %#02x\n", event[0]); } } } static irqreturn_t stmfts_irq_handler(int irq, void *dev) { struct stmfts_data *sdata = dev; int err; mutex_lock(&sdata->mutex); err = stmfts_read_events(sdata); if (unlikely(err)) dev_err(&sdata->client->dev, "failed to read events: %d\n", err); else stmfts_parse_events(sdata); mutex_unlock(&sdata->mutex); return IRQ_HANDLED; } static int stmfts_command(struct stmfts_data *sdata, const u8 cmd) { int err; reinit_completion(&sdata->cmd_done); err = i2c_smbus_write_byte(sdata->client, cmd); if (err) return err; if (!wait_for_completion_timeout(&sdata->cmd_done, msecs_to_jiffies(1000))) return -ETIMEDOUT; return 0; } static int stmfts_input_open(struct input_dev *dev) { struct stmfts_data *sdata = input_get_drvdata(dev); int err; err = pm_runtime_get_sync(&sdata->client->dev); if (err < 0) goto out; err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON); if (err) goto out; mutex_lock(&sdata->mutex); sdata->running = true; if (sdata->hover_enabled) { err = i2c_smbus_write_byte(sdata->client, STMFTS_SS_HOVER_SENSE_ON); if (err) dev_warn(&sdata->client->dev, "failed to enable hover\n"); } mutex_unlock(&sdata->mutex); if (sdata->use_key) { err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_KEY_SENSE_ON); if (err) /* I can still use only the touch screen */ dev_warn(&sdata->client->dev, "failed to enable touchkey\n"); } out: pm_runtime_put_noidle(&sdata->client->dev); return err; } static void stmfts_input_close(struct input_dev *dev) { struct stmfts_data *sdata = input_get_drvdata(dev); int err; err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF); if (err) dev_warn(&sdata->client->dev, "failed to disable touchscreen: %d\n", err); mutex_lock(&sdata->mutex); sdata->running = false; if (sdata->hover_enabled) { err = i2c_smbus_write_byte(sdata->client, STMFTS_SS_HOVER_SENSE_OFF); if (err) dev_warn(&sdata->client->dev, "failed to disable hover: %d\n", err); } mutex_unlock(&sdata->mutex); if (sdata->use_key) { err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_KEY_SENSE_OFF); if (err) dev_warn(&sdata->client->dev, "failed to disable touchkey: %d\n", err); } pm_runtime_put_sync(&sdata->client->dev); } static ssize_t stmfts_sysfs_chip_id(struct device *dev, struct device_attribute *attr, char *buf) { struct stmfts_data *sdata = dev_get_drvdata(dev); return sprintf(buf, "%#x\n", sdata->chip_id); } static ssize_t stmfts_sysfs_chip_version(struct device *dev, struct device_attribute *attr, char *buf) { struct stmfts_data *sdata = dev_get_drvdata(dev); return sprintf(buf, "%u\n", sdata->chip_ver); } static ssize_t stmfts_sysfs_fw_ver(struct device *dev, struct device_attribute *attr, char *buf) { struct stmfts_data *sdata = dev_get_drvdata(dev); return sprintf(buf, "%u\n", sdata->fw_ver); } static ssize_t stmfts_sysfs_config_id(struct device *dev, struct device_attribute *attr, char *buf) { struct stmfts_data *sdata = dev_get_drvdata(dev); return sprintf(buf, "%#x\n", sdata->config_id); } static ssize_t stmfts_sysfs_config_version(struct device *dev, struct device_attribute *attr, char *buf) { struct stmfts_data *sdata = dev_get_drvdata(dev); return sprintf(buf, "%u\n", sdata->config_ver); } static ssize_t stmfts_sysfs_read_status(struct device *dev, struct device_attribute *attr, char *buf) { struct stmfts_data *sdata = dev_get_drvdata(dev); u8 status[4]; int err; err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_STATUS, sizeof(status), status); if (err) return err; return sprintf(buf, "%#02x\n", status[0]); } static ssize_t stmfts_sysfs_hover_enable_read(struct device *dev, struct device_attribute *attr, char *buf) { struct stmfts_data *sdata = dev_get_drvdata(dev); return sprintf(buf, "%u\n", sdata->hover_enabled); } static ssize_t stmfts_sysfs_hover_enable_write(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { struct stmfts_data *sdata = dev_get_drvdata(dev); unsigned long value; int err = 0; if (kstrtoul(buf, 0, &value)) return -EINVAL; mutex_lock(&sdata->mutex); if (value && sdata->hover_enabled) goto out; if (sdata->running) err = i2c_smbus_write_byte(sdata->client, value ? STMFTS_SS_HOVER_SENSE_ON : STMFTS_SS_HOVER_SENSE_OFF); if (!err) sdata->hover_enabled = !!value; out: mutex_unlock(&sdata->mutex); return len; } static DEVICE_ATTR(chip_id, 0444, stmfts_sysfs_chip_id, NULL); static DEVICE_ATTR(chip_version, 0444, stmfts_sysfs_chip_version, NULL); static DEVICE_ATTR(fw_ver, 0444, stmfts_sysfs_fw_ver, NULL); static DEVICE_ATTR(config_id, 0444, stmfts_sysfs_config_id, NULL); static DEVICE_ATTR(config_version, 0444, stmfts_sysfs_config_version, NULL); static DEVICE_ATTR(status, 0444, stmfts_sysfs_read_status, NULL); static DEVICE_ATTR(hover_enable, 0644, stmfts_sysfs_hover_enable_read, stmfts_sysfs_hover_enable_write); static struct attribute *stmfts_sysfs_attrs[] = { &dev_attr_chip_id.attr, &dev_attr_chip_version.attr, &dev_attr_fw_ver.attr, &dev_attr_config_id.attr, &dev_attr_config_version.attr, &dev_attr_status.attr, &dev_attr_hover_enable.attr, NULL }; static struct attribute_group stmfts_attribute_group = { .attrs = stmfts_sysfs_attrs }; static int stmfts_power_on(struct stmfts_data *sdata) { int err; u8 reg[8]; err = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators), sdata->regulators); if (err) return err; /* * The datasheet does not specify the power on time, but considering * that the reset time is < 10ms, I sleep 20ms to be sure */ msleep(20); err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_INFO, sizeof(reg), reg); if (err < 0) return err; if (err != sizeof(reg)) return -EIO; sdata->chip_id = be16_to_cpup((__be16 *)®[6]); sdata->chip_ver = reg[0]; sdata->fw_ver = be16_to_cpup((__be16 *)®[2]); sdata->config_id = reg[4]; sdata->config_ver = reg[5]; enable_irq(sdata->client->irq); msleep(50); err = stmfts_command(sdata, STMFTS_SYSTEM_RESET); if (err) return err; err = stmfts_command(sdata, STMFTS_SLEEP_OUT); if (err) return err; /* optional tuning */ err = stmfts_command(sdata, STMFTS_MS_CX_TUNING); if (err) dev_warn(&sdata->client->dev, "failed to perform mutual auto tune: %d\n", err); /* optional tuning */ err = stmfts_command(sdata, STMFTS_SS_CX_TUNING); if (err) dev_warn(&sdata->client->dev, "failed to perform self auto tune: %d\n", err); err = stmfts_command(sdata, STMFTS_FULL_FORCE_CALIBRATION); if (err) return err; /* * At this point no one is using the touchscreen * and I don't really care about the return value */ (void) i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN); return 0; } static void stmfts_power_off(void *data) { struct stmfts_data *sdata = data; disable_irq(sdata->client->irq); regulator_bulk_disable(ARRAY_SIZE(sdata->regulators), sdata->regulators); } /* This function is void because I don't want to prevent using the touch key * only because the LEDs don't get registered */ static int stmfts_enable_led(struct stmfts_data *sdata) { int err; /* get the regulator for powering the leds on */ sdata->ledvdd = devm_regulator_get(&sdata->client->dev, "ledvdd"); if (IS_ERR(sdata->ledvdd)) return PTR_ERR(sdata->ledvdd); sdata->led_cdev.name = STMFTS_DEV_NAME; sdata->led_cdev.max_brightness = LED_ON; sdata->led_cdev.brightness = LED_OFF; sdata->led_cdev.brightness_set_blocking = stmfts_brightness_set; sdata->led_cdev.brightness_get = stmfts_brightness_get; err = devm_led_classdev_register(&sdata->client->dev, &sdata->led_cdev); if (err) { devm_regulator_put(sdata->ledvdd); return err; } return 0; } static int stmfts_probe(struct i2c_client *client, const struct i2c_device_id *id) { int err; struct stmfts_data *sdata; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) return -ENODEV; sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL); if (!sdata) return -ENOMEM; i2c_set_clientdata(client, sdata); sdata->client = client; mutex_init(&sdata->mutex); init_completion(&sdata->cmd_done); sdata->regulators[STMFTS_REGULATOR_VDD].supply = "vdd"; sdata->regulators[STMFTS_REGULATOR_AVDD].supply = "avdd"; err = devm_regulator_bulk_get(&client->dev, ARRAY_SIZE(sdata->regulators), sdata->regulators); if (err) return err; sdata->input = devm_input_allocate_device(&client->dev); if (!sdata->input) return -ENOMEM; sdata->input->name = STMFTS_DEV_NAME; sdata->input->id.bustype = BUS_I2C; sdata->input->open = stmfts_input_open; sdata->input->close = stmfts_input_close; input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_X); input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_Y); touchscreen_parse_properties(sdata->input, true, &sdata->prop); input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0); input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0); input_set_abs_params(sdata->input, ABS_MT_ORIENTATION, 0, 255, 0, 0); input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0); input_set_abs_params(sdata->input, ABS_DISTANCE, 0, 255, 0, 0); sdata->use_key = device_property_read_bool(&client->dev, "touch-key-connected"); if (sdata->use_key) { input_set_capability(sdata->input, EV_KEY, KEY_MENU); input_set_capability(sdata->input, EV_KEY, KEY_BACK); } err = input_mt_init_slots(sdata->input, STMFTS_MAX_FINGERS, INPUT_MT_DIRECT); if (err) return err; input_set_drvdata(sdata->input, sdata); /* * stmfts_power_on expects interrupt to be disabled, but * at this point the device is still off and I do not trust * the status of the irq line that can generate some spurious * interrupts. To be on the safe side it's better to not enable * the interrupts during their request. */ irq_set_status_flags(client->irq, IRQ_NOAUTOEN); err = devm_request_threaded_irq(&client->dev, client->irq, NULL, stmfts_irq_handler, IRQF_ONESHOT, "stmfts_irq", sdata); if (err) return err; dev_dbg(&client->dev, "initializing ST-Microelectronics FTS...\n"); err = stmfts_power_on(sdata); if (err) return err; err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata); if (err) return err; err = input_register_device(sdata->input); if (err) return err; if (sdata->use_key) { err = stmfts_enable_led(sdata); if (err) { /* * Even if the LEDs have failed to be initialized and * used in the driver, I can still use the device even * without LEDs. The ledvdd regulator pointer will be * used as a flag. */ dev_warn(&client->dev, "unable to use touchkey leds\n"); sdata->ledvdd = NULL; } } err = devm_device_add_group(&client->dev, &stmfts_attribute_group); if (err) return err; pm_runtime_enable(&client->dev); device_enable_async_suspend(&client->dev); return 0; } static int stmfts_remove(struct i2c_client *client) { pm_runtime_disable(&client->dev); return 0; } static int __maybe_unused stmfts_runtime_suspend(struct device *dev) { struct stmfts_data *sdata = dev_get_drvdata(dev); int ret; ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN); if (ret) dev_warn(dev, "failed to suspend device: %d\n", ret); return ret; } static int __maybe_unused stmfts_runtime_resume(struct device *dev) { struct stmfts_data *sdata = dev_get_drvdata(dev); int ret; ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT); if (ret) dev_err(dev, "failed to resume device: %d\n", ret); return ret; } static int __maybe_unused stmfts_suspend(struct device *dev) { struct stmfts_data *sdata = dev_get_drvdata(dev); stmfts_power_off(sdata); return 0; } static int __maybe_unused stmfts_resume(struct device *dev) { struct stmfts_data *sdata = dev_get_drvdata(dev); return stmfts_power_on(sdata); } static const struct dev_pm_ops stmfts_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(stmfts_suspend, stmfts_resume) SET_RUNTIME_PM_OPS(stmfts_runtime_suspend, stmfts_runtime_resume, NULL) }; #ifdef CONFIG_OF static const struct of_device_id stmfts_of_match[] = { { .compatible = "st,stmfts", }, { }, }; MODULE_DEVICE_TABLE(of, stmfts_of_match); #endif static const struct i2c_device_id stmfts_id[] = { { "stmfts", 0 }, { }, }; MODULE_DEVICE_TABLE(i2c, stmfts_id); static struct i2c_driver stmfts_driver = { .driver = { .name = STMFTS_DEV_NAME, .of_match_table = of_match_ptr(stmfts_of_match), .pm = &stmfts_pm_ops, .probe_type = PROBE_PREFER_ASYNCHRONOUS, }, .probe = stmfts_probe, .remove = stmfts_remove, .id_table = stmfts_id, }; module_i2c_driver(stmfts_driver); MODULE_AUTHOR("Andi Shyti "); MODULE_DESCRIPTION("STMicroelectronics FTS Touch Screen"); MODULE_LICENSE("GPL v2");