// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2012-2013 MundoReader S.L. * Author: Heiko Stuebner * * based in parts on Nook zforce driver * * Copyright (C) 2010 Barnes & Noble, Inc. * Author: Pieter Truter */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define WAIT_TIMEOUT msecs_to_jiffies(1000) #define FRAME_START 0xee #define FRAME_MAXSIZE 257 /* Offsets of the different parts of the payload the controller sends */ #define PAYLOAD_HEADER 0 #define PAYLOAD_LENGTH 1 #define PAYLOAD_BODY 2 /* Response offsets */ #define RESPONSE_ID 0 #define RESPONSE_DATA 1 /* Commands */ #define COMMAND_DEACTIVATE 0x00 #define COMMAND_INITIALIZE 0x01 #define COMMAND_RESOLUTION 0x02 #define COMMAND_SETCONFIG 0x03 #define COMMAND_DATAREQUEST 0x04 #define COMMAND_SCANFREQ 0x08 #define COMMAND_STATUS 0X1e /* * Responses the controller sends as a result of * command requests */ #define RESPONSE_DEACTIVATE 0x00 #define RESPONSE_INITIALIZE 0x01 #define RESPONSE_RESOLUTION 0x02 #define RESPONSE_SETCONFIG 0x03 #define RESPONSE_SCANFREQ 0x08 #define RESPONSE_STATUS 0X1e /* * Notifications are sent by the touch controller without * being requested by the driver and include for example * touch indications */ #define NOTIFICATION_TOUCH 0x04 #define NOTIFICATION_BOOTCOMPLETE 0x07 #define NOTIFICATION_OVERRUN 0x25 #define NOTIFICATION_PROXIMITY 0x26 #define NOTIFICATION_INVALID_COMMAND 0xfe #define ZFORCE_REPORT_POINTS 2 #define ZFORCE_MAX_AREA 0xff #define STATE_DOWN 0 #define STATE_MOVE 1 #define STATE_UP 2 #define SETCONFIG_DUALTOUCH (1 << 0) struct zforce_point { int coord_x; int coord_y; int state; int id; int area_major; int area_minor; int orientation; int pressure; int prblty; }; /* * @client the i2c_client * @input the input device * @suspending in the process of going to suspend (don't emit wakeup * events for commands executed to suspend the device) * @suspended device suspended * @command_done completion to wait for the command result * @command_waiting the id of the command that is currently waiting * for a result * @command_result returned result of the command */ struct zforce_ts { struct i2c_client *client; struct input_dev *input; struct touchscreen_properties prop; char phys[32]; struct gpio_desc *gpio_int; struct gpio_desc *gpio_rst; bool suspending; bool suspended; bool boot_complete; /* Firmware version information */ u16 version_major; u16 version_minor; u16 version_build; u16 version_rev; struct completion command_done; int command_waiting; int command_result; }; static int zforce_command(struct zforce_ts *ts, u8 cmd) { struct i2c_client *client = ts->client; char buf[3]; int ret; dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd); buf[0] = FRAME_START; buf[1] = 1; /* data size, command only */ buf[2] = cmd; ret = i2c_master_send(client, &buf[0], ARRAY_SIZE(buf)); if (ret < 0) { dev_err(&client->dev, "i2c send data request error: %d\n", ret); return ret; } return 0; } static int zforce_send_wait(struct zforce_ts *ts, const char *buf, int len) { struct i2c_client *client = ts->client; int ret; dev_dbg(&client->dev, "sending %d bytes for command 0x%x\n", buf[1], buf[2]); ts->command_waiting = buf[2]; ret = i2c_master_send(client, buf, len); if (ret < 0) { dev_err(&client->dev, "i2c send data request error: %d\n", ret); return ret; } dev_dbg(&client->dev, "waiting for result for command 0x%x\n", buf[2]); if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) return -ETIME; ret = ts->command_result; return 0; } static int zforce_command_wait(struct zforce_ts *ts, u8 cmd) { struct i2c_client *client = ts->client; char buf[3]; int error; dev_dbg(&client->dev, "%s: 0x%x\n", __func__, cmd); buf[0] = FRAME_START; buf[1] = 1; /* data size, command only */ buf[2] = cmd; error = zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf)); if (error) { dev_err(&client->dev, "i2c send data request error: %d\n", error); return error; } return 0; } static int zforce_resolution(struct zforce_ts *ts, u16 x, u16 y) { struct i2c_client *client = ts->client; char buf[7] = { FRAME_START, 5, COMMAND_RESOLUTION, (x & 0xff), ((x >> 8) & 0xff), (y & 0xff), ((y >> 8) & 0xff) }; dev_dbg(&client->dev, "set resolution to (%d,%d)\n", x, y); return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf)); } static int zforce_scan_frequency(struct zforce_ts *ts, u16 idle, u16 finger, u16 stylus) { struct i2c_client *client = ts->client; char buf[9] = { FRAME_START, 7, COMMAND_SCANFREQ, (idle & 0xff), ((idle >> 8) & 0xff), (finger & 0xff), ((finger >> 8) & 0xff), (stylus & 0xff), ((stylus >> 8) & 0xff) }; dev_dbg(&client->dev, "set scan frequency to (idle: %d, finger: %d, stylus: %d)\n", idle, finger, stylus); return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf)); } static int zforce_setconfig(struct zforce_ts *ts, char b1) { struct i2c_client *client = ts->client; char buf[7] = { FRAME_START, 5, COMMAND_SETCONFIG, b1, 0, 0, 0 }; dev_dbg(&client->dev, "set config to (%d)\n", b1); return zforce_send_wait(ts, &buf[0], ARRAY_SIZE(buf)); } static int zforce_start(struct zforce_ts *ts) { struct i2c_client *client = ts->client; int error; dev_dbg(&client->dev, "starting device\n"); error = zforce_command_wait(ts, COMMAND_INITIALIZE); if (error) { dev_err(&client->dev, "Unable to initialize, %d\n", error); return error; } error = zforce_resolution(ts, ts->prop.max_x, ts->prop.max_y); if (error) { dev_err(&client->dev, "Unable to set resolution, %d\n", error); goto err_deactivate; } error = zforce_scan_frequency(ts, 10, 50, 50); if (error) { dev_err(&client->dev, "Unable to set scan frequency, %d\n", error); goto err_deactivate; } error = zforce_setconfig(ts, SETCONFIG_DUALTOUCH); if (error) { dev_err(&client->dev, "Unable to set config\n"); goto err_deactivate; } /* start sending touch events */ error = zforce_command(ts, COMMAND_DATAREQUEST); if (error) { dev_err(&client->dev, "Unable to request data\n"); goto err_deactivate; } /* * Per NN, initial cal. take max. of 200msec. * Allow time to complete this calibration */ msleep(200); return 0; err_deactivate: zforce_command_wait(ts, COMMAND_DEACTIVATE); return error; } static int zforce_stop(struct zforce_ts *ts) { struct i2c_client *client = ts->client; int error; dev_dbg(&client->dev, "stopping device\n"); /* Deactivates touch sensing and puts the device into sleep. */ error = zforce_command_wait(ts, COMMAND_DEACTIVATE); if (error) { dev_err(&client->dev, "could not deactivate device, %d\n", error); return error; } return 0; } static int zforce_touch_event(struct zforce_ts *ts, u8 *payload) { struct i2c_client *client = ts->client; struct zforce_point point; int count, i, num = 0; u8 *p; count = payload[0]; if (count > ZFORCE_REPORT_POINTS) { dev_warn(&client->dev, "too many coordinates %d, expected max %d\n", count, ZFORCE_REPORT_POINTS); count = ZFORCE_REPORT_POINTS; } for (i = 0; i < count; i++) { p = &payload[i * 9 + 1]; point.coord_x = get_unaligned_le16(&p[0]); point.coord_y = get_unaligned_le16(&p[2]); if (point.coord_x > ts->prop.max_x || point.coord_y > ts->prop.max_y) { dev_warn(&client->dev, "coordinates (%d,%d) invalid\n", point.coord_x, point.coord_y); point.coord_x = point.coord_y = 0; } point.state = p[4] & 0x0f; point.id = (p[4] & 0xf0) >> 4; /* determine touch major, minor and orientation */ point.area_major = max(p[5], p[6]); point.area_minor = min(p[5], p[6]); point.orientation = p[5] > p[6]; point.pressure = p[7]; point.prblty = p[8]; dev_dbg(&client->dev, "point %d/%d: state %d, id %d, pressure %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n", i, count, point.state, point.id, point.pressure, point.prblty, point.coord_x, point.coord_y, point.area_major, point.area_minor, point.orientation); /* the zforce id starts with "1", so needs to be decreased */ input_mt_slot(ts->input, point.id - 1); if (input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, point.state != STATE_UP)) { touchscreen_report_pos(ts->input, &ts->prop, point.coord_x, point.coord_y, true); input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR, point.area_major); input_report_abs(ts->input, ABS_MT_TOUCH_MINOR, point.area_minor); input_report_abs(ts->input, ABS_MT_ORIENTATION, point.orientation); num++; } } input_mt_sync_frame(ts->input); input_mt_report_finger_count(ts->input, num); input_sync(ts->input); return 0; } static int zforce_read_packet(struct zforce_ts *ts, u8 *buf) { struct i2c_client *client = ts->client; int ret; /* read 2 byte message header */ ret = i2c_master_recv(client, buf, 2); if (ret < 0) { dev_err(&client->dev, "error reading header: %d\n", ret); return ret; } if (buf[PAYLOAD_HEADER] != FRAME_START) { dev_err(&client->dev, "invalid frame start: %d\n", buf[0]); return -EIO; } if (buf[PAYLOAD_LENGTH] == 0) { dev_err(&client->dev, "invalid payload length: %d\n", buf[PAYLOAD_LENGTH]); return -EIO; } /* read the message */ ret = i2c_master_recv(client, &buf[PAYLOAD_BODY], buf[PAYLOAD_LENGTH]); if (ret < 0) { dev_err(&client->dev, "error reading payload: %d\n", ret); return ret; } dev_dbg(&client->dev, "read %d bytes for response command 0x%x\n", buf[PAYLOAD_LENGTH], buf[PAYLOAD_BODY]); return 0; } static void zforce_complete(struct zforce_ts *ts, int cmd, int result) { struct i2c_client *client = ts->client; if (ts->command_waiting == cmd) { dev_dbg(&client->dev, "completing command 0x%x\n", cmd); ts->command_result = result; complete(&ts->command_done); } else { dev_dbg(&client->dev, "command %d not for us\n", cmd); } } static irqreturn_t zforce_irq(int irq, void *dev_id) { struct zforce_ts *ts = dev_id; struct i2c_client *client = ts->client; if (ts->suspended && device_may_wakeup(&client->dev)) pm_wakeup_event(&client->dev, 500); return IRQ_WAKE_THREAD; } static irqreturn_t zforce_irq_thread(int irq, void *dev_id) { struct zforce_ts *ts = dev_id; struct i2c_client *client = ts->client; int error; u8 payload_buffer[FRAME_MAXSIZE]; u8 *payload; bool suspending; /* * When still suspended, return. * Due to the level-interrupt we will get re-triggered later. */ if (ts->suspended) { msleep(20); return IRQ_HANDLED; } dev_dbg(&client->dev, "handling interrupt\n"); /* Don't emit wakeup events from commands run by zforce_suspend */ suspending = READ_ONCE(ts->suspending); if (!suspending && device_may_wakeup(&client->dev)) pm_stay_awake(&client->dev); /* * Run at least once and exit the loop if * - the optional interrupt GPIO isn't specified * (there is only one packet read per ISR invocation, then) * or * - the GPIO isn't active any more * (packet read until the level GPIO indicates that there is * no IRQ any more) */ do { error = zforce_read_packet(ts, payload_buffer); if (error) { dev_err(&client->dev, "could not read packet, ret: %d\n", error); break; } payload = &payload_buffer[PAYLOAD_BODY]; switch (payload[RESPONSE_ID]) { case NOTIFICATION_TOUCH: /* * Always report touch-events received while * suspending, when being a wakeup source */ if (suspending && device_may_wakeup(&client->dev)) pm_wakeup_event(&client->dev, 500); zforce_touch_event(ts, &payload[RESPONSE_DATA]); break; case NOTIFICATION_BOOTCOMPLETE: ts->boot_complete = payload[RESPONSE_DATA]; zforce_complete(ts, payload[RESPONSE_ID], 0); break; case RESPONSE_INITIALIZE: case RESPONSE_DEACTIVATE: case RESPONSE_SETCONFIG: case RESPONSE_RESOLUTION: case RESPONSE_SCANFREQ: zforce_complete(ts, payload[RESPONSE_ID], payload[RESPONSE_DATA]); break; case RESPONSE_STATUS: /* * Version Payload Results * [2:major] [2:minor] [2:build] [2:rev] */ ts->version_major = get_unaligned_le16(&payload[RESPONSE_DATA]); ts->version_minor = get_unaligned_le16(&payload[RESPONSE_DATA + 2]); ts->version_build = get_unaligned_le16(&payload[RESPONSE_DATA + 4]); ts->version_rev = get_unaligned_le16(&payload[RESPONSE_DATA + 6]); dev_dbg(&ts->client->dev, "Firmware Version %04x:%04x %04x:%04x\n", ts->version_major, ts->version_minor, ts->version_build, ts->version_rev); zforce_complete(ts, payload[RESPONSE_ID], 0); break; case NOTIFICATION_INVALID_COMMAND: dev_err(&ts->client->dev, "invalid command: 0x%x\n", payload[RESPONSE_DATA]); break; default: dev_err(&ts->client->dev, "unrecognized response id: 0x%x\n", payload[RESPONSE_ID]); break; } } while (gpiod_get_value_cansleep(ts->gpio_int)); if (!suspending && device_may_wakeup(&client->dev)) pm_relax(&client->dev); dev_dbg(&client->dev, "finished interrupt\n"); return IRQ_HANDLED; } static int zforce_input_open(struct input_dev *dev) { struct zforce_ts *ts = input_get_drvdata(dev); return zforce_start(ts); } static void zforce_input_close(struct input_dev *dev) { struct zforce_ts *ts = input_get_drvdata(dev); struct i2c_client *client = ts->client; int error; error = zforce_stop(ts); if (error) dev_warn(&client->dev, "stopping zforce failed\n"); } static int __zforce_suspend(struct zforce_ts *ts) { struct i2c_client *client = ts->client; struct input_dev *input = ts->input; int error; guard(mutex)(&input->mutex); /* * When configured as a wakeup source device should always wake * the system, therefore start device if necessary. */ if (device_may_wakeup(&client->dev)) { dev_dbg(&client->dev, "suspend while being a wakeup source\n"); /* Need to start device, if not open, to be a wakeup source. */ if (!input_device_enabled(input)) { error = zforce_start(ts); if (error) return error; } enable_irq_wake(client->irq); } else if (input_device_enabled(input)) { dev_dbg(&client->dev, "suspend without being a wakeup source\n"); error = zforce_stop(ts); if (error) return error; disable_irq(client->irq); } ts->suspended = true; return 0; } static int zforce_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct zforce_ts *ts = i2c_get_clientdata(client); int ret; WRITE_ONCE(ts->suspending, true); smp_mb(); ret = __zforce_suspend(ts); smp_mb(); WRITE_ONCE(ts->suspending, false); return ret; } static int zforce_resume(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct zforce_ts *ts = i2c_get_clientdata(client); struct input_dev *input = ts->input; int error; guard(mutex)(&input->mutex); ts->suspended = false; if (device_may_wakeup(&client->dev)) { dev_dbg(&client->dev, "resume from being a wakeup source\n"); disable_irq_wake(client->irq); /* need to stop device if it was not open on suspend */ if (!input_device_enabled(input)) { error = zforce_stop(ts); if (error) return error; } } else if (input_device_enabled(input)) { dev_dbg(&client->dev, "resume without being a wakeup source\n"); enable_irq(client->irq); error = zforce_start(ts); if (error) return error; } return 0; } static DEFINE_SIMPLE_DEV_PM_OPS(zforce_pm_ops, zforce_suspend, zforce_resume); static void zforce_reset(void *data) { struct zforce_ts *ts = data; gpiod_set_value_cansleep(ts->gpio_rst, 1); udelay(10); } static void zforce_ts_parse_legacy_properties(struct zforce_ts *ts) { u32 x_max = 0; u32 y_max = 0; device_property_read_u32(&ts->client->dev, "x-size", &x_max); input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, x_max, 0, 0); device_property_read_u32(&ts->client->dev, "y-size", &y_max); input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, y_max, 0, 0); } static int zforce_probe(struct i2c_client *client) { struct zforce_ts *ts; struct input_dev *input_dev; int error; ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL); if (!ts) return -ENOMEM; ts->gpio_rst = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH); error = PTR_ERR_OR_ZERO(ts->gpio_rst); if (error) return dev_err_probe(&client->dev, error, "failed to request reset GPIO\n"); if (ts->gpio_rst) { ts->gpio_int = devm_gpiod_get_optional(&client->dev, "irq", GPIOD_IN); error = PTR_ERR_OR_ZERO(ts->gpio_int); if (error) return dev_err_probe(&client->dev, error, "failed to request interrupt GPIO\n"); } else { /* * Deprecated GPIO handling for compatibility * with legacy binding. */ /* INT GPIO */ ts->gpio_int = devm_gpiod_get_index(&client->dev, NULL, 0, GPIOD_IN); error = PTR_ERR_OR_ZERO(ts->gpio_int); if (error) return dev_err_probe(&client->dev, error, "failed to request interrupt GPIO\n"); /* RST GPIO */ ts->gpio_rst = devm_gpiod_get_index(&client->dev, NULL, 1, GPIOD_OUT_HIGH); error = PTR_ERR_OR_ZERO(ts->gpio_rst); if (error) return dev_err_probe(&client->dev, error, "failed to request reset GPIO\n"); } error = devm_regulator_get_enable(&client->dev, "vdd"); if (error) return dev_err_probe(&client->dev, error, "failed to request vdd supply\n"); /* * According to datasheet add 100us grace time after regular * regulator enable delay. */ usleep_range(100, 200); error = devm_add_action_or_reset(&client->dev, zforce_reset, ts); if (error) return dev_err_probe(&client->dev, error, "failed to register reset action\n"); snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&client->dev)); input_dev = devm_input_allocate_device(&client->dev); if (!input_dev) return dev_err_probe(&client->dev, -ENOMEM, "could not allocate input device\n"); ts->client = client; ts->input = input_dev; input_dev->name = "Neonode zForce touchscreen"; input_dev->phys = ts->phys; input_dev->id.bustype = BUS_I2C; input_dev->open = zforce_input_open; input_dev->close = zforce_input_close; zforce_ts_parse_legacy_properties(ts); touchscreen_parse_properties(input_dev, true, &ts->prop); if (ts->prop.max_x == 0 || ts->prop.max_y == 0) return dev_err_probe(&client->dev, -EINVAL, "no size specified"); input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, ZFORCE_MAX_AREA, 0, 0); input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0, ZFORCE_MAX_AREA, 0, 0); input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0); error = input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, INPUT_MT_DIRECT); if (error) return error; input_set_drvdata(ts->input, ts); init_completion(&ts->command_done); /* * The zforce pulls the interrupt low when it has data ready. * After it is triggered the isr thread runs until all the available * packets have been read and the interrupt is high again. * Therefore we can trigger the interrupt anytime it is low and do * not need to limit it to the interrupt edge. */ error = devm_request_threaded_irq(&client->dev, client->irq, zforce_irq, zforce_irq_thread, IRQF_ONESHOT, input_dev->name, ts); if (error) return dev_err_probe(&client->dev, error, "irq %d request failed\n", client->irq); i2c_set_clientdata(client, ts); /* let the controller boot */ gpiod_set_value_cansleep(ts->gpio_rst, 0); ts->command_waiting = NOTIFICATION_BOOTCOMPLETE; if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0) dev_warn(&client->dev, "bootcomplete timed out\n"); /* need to start device to get version information */ error = zforce_command_wait(ts, COMMAND_INITIALIZE); if (error) return dev_err_probe(&client->dev, error, "unable to initialize\n"); /* this gets the firmware version among other information */ error = zforce_command_wait(ts, COMMAND_STATUS); if (error) { dev_err_probe(&client->dev, error, "couldn't get status\n"); zforce_stop(ts); return error; } /* stop device and put it into sleep until it is opened */ error = zforce_stop(ts); if (error) return error; device_set_wakeup_capable(&client->dev, true); error = input_register_device(input_dev); if (error) return dev_err_probe(&client->dev, error, "could not register input device\n"); return 0; } static const struct i2c_device_id zforce_idtable[] = { { "zforce-ts" }, { } }; MODULE_DEVICE_TABLE(i2c, zforce_idtable); #ifdef CONFIG_OF static const struct of_device_id zforce_dt_idtable[] = { { .compatible = "neonode,zforce" }, {}, }; MODULE_DEVICE_TABLE(of, zforce_dt_idtable); #endif static struct i2c_driver zforce_driver = { .driver = { .name = "zforce-ts", .pm = pm_sleep_ptr(&zforce_pm_ops), .of_match_table = of_match_ptr(zforce_dt_idtable), .probe_type = PROBE_PREFER_ASYNCHRONOUS, }, .probe = zforce_probe, .id_table = zforce_idtable, }; module_i2c_driver(zforce_driver); MODULE_AUTHOR("Heiko Stuebner "); MODULE_DESCRIPTION("zForce TouchScreen Driver"); MODULE_LICENSE("GPL");