// SPDX-License-Identifier: GPL-2.0-or-later /* * Driver for ELAN eKTF2127 i2c touchscreen controller * * For this driver the layout of the Chipone icn8318 i2c * touchscreencontroller is used. * * Author: * Michel Verlaan * Siebren Vroegindeweij * * Original chipone_icn8318 driver: * Hans de Goede */ #include #include #include #include #include #include #include #include #include /* Packet header defines (first byte of data send / received) */ #define EKTF2127_NOISE 0x40 #define EKTF2127_RESPONSE 0x52 #define EKTF2127_REQUEST 0x53 #define EKTF2127_HELLO 0x55 #define EKTF2127_REPORT 0x5d #define EKTF2127_CALIB_DONE 0x66 /* Register defines (second byte of data send / received) */ #define EKTF2127_ENV_NOISY 0x41 #define EKTF2127_HEIGHT 0x60 #define EKTF2127_WIDTH 0x63 /* 2 bytes header + 5 * 3 bytes coordinates + 3 bytes pressure info + footer */ #define EKTF2127_TOUCH_REPORT_SIZE 21 #define EKTF2127_MAX_TOUCHES 5 struct ektf2127_ts { struct i2c_client *client; struct input_dev *input; struct gpio_desc *power_gpios; struct touchscreen_properties prop; }; static void ektf2127_parse_coordinates(const u8 *buf, unsigned int touch_count, struct input_mt_pos *touches) { int index = 0; int i; for (i = 0; i < touch_count; i++) { index = 2 + i * 3; touches[i].x = (buf[index] & 0x0f); touches[i].x <<= 8; touches[i].x |= buf[index + 2]; touches[i].y = (buf[index] & 0xf0); touches[i].y <<= 4; touches[i].y |= buf[index + 1]; } } static void ektf2127_report_event(struct ektf2127_ts *ts, const u8 *buf) { struct input_mt_pos touches[EKTF2127_MAX_TOUCHES]; int slots[EKTF2127_MAX_TOUCHES]; unsigned int touch_count, i; touch_count = buf[1] & 0x07; if (touch_count > EKTF2127_MAX_TOUCHES) { dev_err(&ts->client->dev, "Too many touches %d > %d\n", touch_count, EKTF2127_MAX_TOUCHES); touch_count = EKTF2127_MAX_TOUCHES; } ektf2127_parse_coordinates(buf, touch_count, touches); input_mt_assign_slots(ts->input, slots, touches, touch_count, 0); for (i = 0; i < touch_count; i++) { input_mt_slot(ts->input, slots[i]); input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true); touchscreen_report_pos(ts->input, &ts->prop, touches[i].x, touches[i].y, true); } input_mt_sync_frame(ts->input); input_sync(ts->input); } static irqreturn_t ektf2127_irq(int irq, void *dev_id) { struct ektf2127_ts *ts = dev_id; struct device *dev = &ts->client->dev; char buf[EKTF2127_TOUCH_REPORT_SIZE]; int ret; ret = i2c_master_recv(ts->client, buf, EKTF2127_TOUCH_REPORT_SIZE); if (ret != EKTF2127_TOUCH_REPORT_SIZE) { dev_err(dev, "Error reading touch data: %d\n", ret); goto out; } switch (buf[0]) { case EKTF2127_REPORT: ektf2127_report_event(ts, buf); break; case EKTF2127_NOISE: if (buf[1] == EKTF2127_ENV_NOISY) dev_dbg(dev, "Environment is electrically noisy\n"); break; case EKTF2127_HELLO: case EKTF2127_CALIB_DONE: break; default: dev_err(dev, "Unexpected packet header byte %#02x\n", buf[0]); break; } out: return IRQ_HANDLED; } static int ektf2127_start(struct input_dev *dev) { struct ektf2127_ts *ts = input_get_drvdata(dev); enable_irq(ts->client->irq); gpiod_set_value_cansleep(ts->power_gpios, 1); return 0; } static void ektf2127_stop(struct input_dev *dev) { struct ektf2127_ts *ts = input_get_drvdata(dev); disable_irq(ts->client->irq); gpiod_set_value_cansleep(ts->power_gpios, 0); } static int __maybe_unused ektf2127_suspend(struct device *dev) { struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev)); mutex_lock(&ts->input->mutex); if (ts->input->users) ektf2127_stop(ts->input); mutex_unlock(&ts->input->mutex); return 0; } static int __maybe_unused ektf2127_resume(struct device *dev) { struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev)); mutex_lock(&ts->input->mutex); if (ts->input->users) ektf2127_start(ts->input); mutex_unlock(&ts->input->mutex); return 0; } static SIMPLE_DEV_PM_OPS(ektf2127_pm_ops, ektf2127_suspend, ektf2127_resume); static int ektf2127_query_dimension(struct i2c_client *client, bool width) { struct device *dev = &client->dev; const char *what = width ? "width" : "height"; u8 what_code = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT; u8 buf[4]; int ret; int error; /* Request dimension */ buf[0] = EKTF2127_REQUEST; buf[1] = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT; buf[2] = 0x00; buf[3] = 0x00; ret = i2c_master_send(client, buf, sizeof(buf)); if (ret != sizeof(buf)) { error = ret < 0 ? ret : -EIO; dev_err(dev, "Failed to request %s: %d\n", what, error); return error; } msleep(20); /* Read response */ ret = i2c_master_recv(client, buf, sizeof(buf)); if (ret != sizeof(buf)) { error = ret < 0 ? ret : -EIO; dev_err(dev, "Failed to receive %s data: %d\n", what, error); return error; } if (buf[0] != EKTF2127_RESPONSE || buf[1] != what_code) { dev_err(dev, "Unexpected %s data: %#02x %#02x\n", what, buf[0], buf[1]); return -EIO; } return (((buf[3] & 0xf0) << 4) | buf[2]) - 1; } static int ektf2127_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct ektf2127_ts *ts; struct input_dev *input; u8 buf[4]; int max_x, max_y; int error; if (!client->irq) { dev_err(dev, "Error no irq specified\n"); return -EINVAL; } ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); if (!ts) return -ENOMEM; /* This requests the gpio *and* turns on the touchscreen controller */ ts->power_gpios = devm_gpiod_get(dev, "power", GPIOD_OUT_HIGH); if (IS_ERR(ts->power_gpios)) { error = PTR_ERR(ts->power_gpios); if (error != -EPROBE_DEFER) dev_err(dev, "Error getting power gpio: %d\n", error); return error; } input = devm_input_allocate_device(dev); if (!input) return -ENOMEM; input->name = client->name; input->id.bustype = BUS_I2C; input->open = ektf2127_start; input->close = ektf2127_stop; ts->client = client; /* Read hello (ignore result, depends on initial power state) */ msleep(20); i2c_master_recv(ts->client, buf, sizeof(buf)); /* Read resolution from chip */ max_x = ektf2127_query_dimension(client, true); if (max_x < 0) return max_x; max_y = ektf2127_query_dimension(client, false); if (max_y < 0) return max_y; input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_x, 0, 0); input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_y, 0, 0); touchscreen_parse_properties(input, true, &ts->prop); error = input_mt_init_slots(input, EKTF2127_MAX_TOUCHES, INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED | INPUT_MT_TRACK); if (error) return error; ts->input = input; input_set_drvdata(input, ts); error = devm_request_threaded_irq(dev, client->irq, NULL, ektf2127_irq, IRQF_ONESHOT, client->name, ts); if (error) { dev_err(dev, "Error requesting irq: %d\n", error); return error; } /* Stop device till opened */ ektf2127_stop(ts->input); error = input_register_device(input); if (error) return error; i2c_set_clientdata(client, ts); return 0; } #ifdef CONFIG_OF static const struct of_device_id ektf2127_of_match[] = { { .compatible = "elan,ektf2127" }, {} }; MODULE_DEVICE_TABLE(of, ektf2127_of_match); #endif static const struct i2c_device_id ektf2127_i2c_id[] = { { "ektf2127", 0 }, {} }; MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id); static struct i2c_driver ektf2127_driver = { .driver = { .name = "elan_ektf2127", .pm = &ektf2127_pm_ops, .of_match_table = of_match_ptr(ektf2127_of_match), }, .probe = ektf2127_probe, .id_table = ektf2127_i2c_id, }; module_i2c_driver(ektf2127_driver); MODULE_DESCRIPTION("ELAN eKTF2127 I2C Touchscreen Driver"); MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij"); MODULE_LICENSE("GPL");