1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Driver for Novatek NT11205 i2c touchscreen controller as found 4 * on the Acer Iconia One 7 B1-750 tablet. 5 * 6 * Copyright (c) 2023 Hans de Goede <hdegoede@redhat.com> 7 */ 8 9 #include <linux/delay.h> 10 #include <linux/gpio/consumer.h> 11 #include <linux/interrupt.h> 12 #include <linux/i2c.h> 13 #include <linux/input.h> 14 #include <linux/input/mt.h> 15 #include <linux/input/touchscreen.h> 16 #include <linux/module.h> 17 18 #include <linux/unaligned.h> 19 20 #define NVT_TS_TOUCH_START 0x00 21 #define NVT_TS_TOUCH_SIZE 6 22 23 #define NVT_TS_PARAMETERS_START 0x78 24 /* These are offsets from NVT_TS_PARAMETERS_START */ 25 #define NVT_TS_PARAMS_WIDTH 0x04 26 #define NVT_TS_PARAMS_HEIGHT 0x06 27 #define NVT_TS_PARAMS_MAX_TOUCH 0x09 28 #define NVT_TS_PARAMS_MAX_BUTTONS 0x0a 29 #define NVT_TS_PARAMS_IRQ_TYPE 0x0b 30 #define NVT_TS_PARAMS_WAKE_TYPE 0x0c 31 #define NVT_TS_PARAMS_CHIP_ID 0x0e 32 #define NVT_TS_PARAMS_SIZE 0x0f 33 34 #define NVT_TS_SUPPORTED_WAKE_TYPE 0x05 35 #define NVT_TS_SUPPORTED_CHIP_ID 0x05 36 37 #define NVT_TS_MAX_TOUCHES 10 38 #define NVT_TS_MAX_SIZE 4096 39 40 #define NVT_TS_TOUCH_INVALID 0xff 41 #define NVT_TS_TOUCH_SLOT_SHIFT 3 42 #define NVT_TS_TOUCH_TYPE_MASK GENMASK(2, 0) 43 #define NVT_TS_TOUCH_NEW 1 44 #define NVT_TS_TOUCH_UPDATE 2 45 #define NVT_TS_TOUCH_RELEASE 3 46 47 static const int nvt_ts_irq_type[4] = { 48 IRQF_TRIGGER_RISING, 49 IRQF_TRIGGER_FALLING, 50 IRQF_TRIGGER_LOW, 51 IRQF_TRIGGER_HIGH 52 }; 53 54 struct nvt_ts_data { 55 struct i2c_client *client; 56 struct input_dev *input; 57 struct gpio_desc *reset_gpio; 58 struct touchscreen_properties prop; 59 int max_touches; 60 u8 buf[NVT_TS_TOUCH_SIZE * NVT_TS_MAX_TOUCHES]; 61 }; 62 63 static int nvt_ts_read_data(struct i2c_client *client, u8 reg, u8 *data, int count) 64 { 65 struct i2c_msg msg[2] = { 66 { 67 .addr = client->addr, 68 .len = 1, 69 .buf = ®, 70 }, 71 { 72 .addr = client->addr, 73 .flags = I2C_M_RD, 74 .len = count, 75 .buf = data, 76 } 77 }; 78 int ret; 79 80 ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg)); 81 if (ret != ARRAY_SIZE(msg)) { 82 dev_err(&client->dev, "Error reading from 0x%02x: %d\n", reg, ret); 83 return (ret < 0) ? ret : -EIO; 84 } 85 86 return 0; 87 } 88 89 static irqreturn_t nvt_ts_irq(int irq, void *dev_id) 90 { 91 struct nvt_ts_data *data = dev_id; 92 struct device *dev = &data->client->dev; 93 int i, error, slot, x, y; 94 bool active; 95 u8 *touch; 96 97 error = nvt_ts_read_data(data->client, NVT_TS_TOUCH_START, data->buf, 98 data->max_touches * NVT_TS_TOUCH_SIZE); 99 if (error) 100 return IRQ_HANDLED; 101 102 for (i = 0; i < data->max_touches; i++) { 103 touch = &data->buf[i * NVT_TS_TOUCH_SIZE]; 104 105 if (touch[0] == NVT_TS_TOUCH_INVALID) 106 continue; 107 108 slot = touch[0] >> NVT_TS_TOUCH_SLOT_SHIFT; 109 if (slot < 1 || slot > data->max_touches) { 110 dev_warn(dev, "slot %d out of range, ignoring\n", slot); 111 continue; 112 } 113 114 switch (touch[0] & NVT_TS_TOUCH_TYPE_MASK) { 115 case NVT_TS_TOUCH_NEW: 116 case NVT_TS_TOUCH_UPDATE: 117 active = true; 118 break; 119 case NVT_TS_TOUCH_RELEASE: 120 active = false; 121 break; 122 default: 123 dev_warn(dev, "slot %d unknown state %d\n", slot, touch[0] & 7); 124 continue; 125 } 126 127 slot--; 128 x = (touch[1] << 4) | (touch[3] >> 4); 129 y = (touch[2] << 4) | (touch[3] & 0x0f); 130 131 input_mt_slot(data->input, slot); 132 input_mt_report_slot_state(data->input, MT_TOOL_FINGER, active); 133 touchscreen_report_pos(data->input, &data->prop, x, y, true); 134 } 135 136 input_mt_sync_frame(data->input); 137 input_sync(data->input); 138 139 return IRQ_HANDLED; 140 } 141 142 static int nvt_ts_start(struct input_dev *dev) 143 { 144 struct nvt_ts_data *data = input_get_drvdata(dev); 145 146 enable_irq(data->client->irq); 147 gpiod_set_value_cansleep(data->reset_gpio, 0); 148 149 return 0; 150 } 151 152 static void nvt_ts_stop(struct input_dev *dev) 153 { 154 struct nvt_ts_data *data = input_get_drvdata(dev); 155 156 disable_irq(data->client->irq); 157 gpiod_set_value_cansleep(data->reset_gpio, 1); 158 } 159 160 static int nvt_ts_suspend(struct device *dev) 161 { 162 struct nvt_ts_data *data = i2c_get_clientdata(to_i2c_client(dev)); 163 164 mutex_lock(&data->input->mutex); 165 if (input_device_enabled(data->input)) 166 nvt_ts_stop(data->input); 167 mutex_unlock(&data->input->mutex); 168 169 return 0; 170 } 171 172 static int nvt_ts_resume(struct device *dev) 173 { 174 struct nvt_ts_data *data = i2c_get_clientdata(to_i2c_client(dev)); 175 176 mutex_lock(&data->input->mutex); 177 if (input_device_enabled(data->input)) 178 nvt_ts_start(data->input); 179 mutex_unlock(&data->input->mutex); 180 181 return 0; 182 } 183 184 static DEFINE_SIMPLE_DEV_PM_OPS(nvt_ts_pm_ops, nvt_ts_suspend, nvt_ts_resume); 185 186 static int nvt_ts_probe(struct i2c_client *client) 187 { 188 struct device *dev = &client->dev; 189 int error, width, height, irq_type; 190 struct nvt_ts_data *data; 191 struct input_dev *input; 192 193 if (!client->irq) { 194 dev_err(dev, "Error no irq specified\n"); 195 return -EINVAL; 196 } 197 198 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 199 if (!data) 200 return -ENOMEM; 201 202 data->client = client; 203 i2c_set_clientdata(client, data); 204 205 data->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); 206 error = PTR_ERR_OR_ZERO(data->reset_gpio); 207 if (error) { 208 dev_err(dev, "failed to request reset GPIO: %d\n", error); 209 return error; 210 } 211 212 /* Wait for controller to come out of reset before params read */ 213 msleep(100); 214 error = nvt_ts_read_data(data->client, NVT_TS_PARAMETERS_START, 215 data->buf, NVT_TS_PARAMS_SIZE); 216 gpiod_set_value_cansleep(data->reset_gpio, 1); /* Put back in reset */ 217 if (error) 218 return error; 219 220 width = get_unaligned_be16(&data->buf[NVT_TS_PARAMS_WIDTH]); 221 height = get_unaligned_be16(&data->buf[NVT_TS_PARAMS_HEIGHT]); 222 data->max_touches = data->buf[NVT_TS_PARAMS_MAX_TOUCH]; 223 irq_type = data->buf[NVT_TS_PARAMS_IRQ_TYPE]; 224 225 if (width > NVT_TS_MAX_SIZE || height >= NVT_TS_MAX_SIZE || 226 data->max_touches > NVT_TS_MAX_TOUCHES || 227 irq_type >= ARRAY_SIZE(nvt_ts_irq_type) || 228 data->buf[NVT_TS_PARAMS_WAKE_TYPE] != NVT_TS_SUPPORTED_WAKE_TYPE || 229 data->buf[NVT_TS_PARAMS_CHIP_ID] != NVT_TS_SUPPORTED_CHIP_ID) { 230 dev_err(dev, "Unsupported touchscreen parameters: %*ph\n", 231 NVT_TS_PARAMS_SIZE, data->buf); 232 return -EIO; 233 } 234 235 dev_dbg(dev, "Detected %dx%d touchscreen with %d max touches\n", 236 width, height, data->max_touches); 237 238 if (data->buf[NVT_TS_PARAMS_MAX_BUTTONS]) 239 dev_warn(dev, "Touchscreen buttons are not supported\n"); 240 241 input = devm_input_allocate_device(dev); 242 if (!input) 243 return -ENOMEM; 244 245 input->name = client->name; 246 input->id.bustype = BUS_I2C; 247 input->open = nvt_ts_start; 248 input->close = nvt_ts_stop; 249 250 input_set_abs_params(input, ABS_MT_POSITION_X, 0, width - 1, 0, 0); 251 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, height - 1, 0, 0); 252 touchscreen_parse_properties(input, true, &data->prop); 253 254 error = input_mt_init_slots(input, data->max_touches, 255 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED); 256 if (error) 257 return error; 258 259 data->input = input; 260 input_set_drvdata(input, data); 261 262 error = devm_request_threaded_irq(dev, client->irq, NULL, nvt_ts_irq, 263 IRQF_ONESHOT | IRQF_NO_AUTOEN | 264 nvt_ts_irq_type[irq_type], 265 client->name, data); 266 if (error) { 267 dev_err(dev, "failed to request irq: %d\n", error); 268 return error; 269 } 270 271 error = input_register_device(input); 272 if (error) { 273 dev_err(dev, "failed to register input device: %d\n", error); 274 return error; 275 } 276 277 return 0; 278 } 279 280 static const struct i2c_device_id nvt_ts_i2c_id[] = { 281 { "NVT-ts" }, 282 { } 283 }; 284 MODULE_DEVICE_TABLE(i2c, nvt_ts_i2c_id); 285 286 static struct i2c_driver nvt_ts_driver = { 287 .driver = { 288 .name = "novatek-nvt-ts", 289 .pm = pm_sleep_ptr(&nvt_ts_pm_ops), 290 }, 291 .probe = nvt_ts_probe, 292 .id_table = nvt_ts_i2c_id, 293 }; 294 295 module_i2c_driver(nvt_ts_driver); 296 297 MODULE_DESCRIPTION("Novatek NT11205 touchscreen driver"); 298 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 299 MODULE_LICENSE("GPL"); 300