1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Wacom Penabled Driver for I2C 4 * 5 * Copyright (c) 2011 - 2013 Tatsunosuke Tobita, Wacom. 6 * <tobita.tatsunosuke@wacom.co.jp> 7 */ 8 9 #include <linux/bits.h> 10 #include <linux/module.h> 11 #include <linux/input.h> 12 #include <linux/i2c.h> 13 #include <linux/slab.h> 14 #include <linux/irq.h> 15 #include <linux/interrupt.h> 16 #include <asm/unaligned.h> 17 18 /* Bitmasks (for data[3]) */ 19 #define WACOM_TIP_SWITCH BIT(0) 20 #define WACOM_BARREL_SWITCH BIT(1) 21 #define WACOM_ERASER BIT(2) 22 #define WACOM_INVERT BIT(3) 23 #define WACOM_BARREL_SWITCH_2 BIT(4) 24 #define WACOM_IN_PROXIMITY BIT(5) 25 26 /* Registers */ 27 #define WACOM_COMMAND_LSB 0x04 28 #define WACOM_COMMAND_MSB 0x00 29 30 #define WACOM_DATA_LSB 0x05 31 #define WACOM_DATA_MSB 0x00 32 33 /* Report types */ 34 #define REPORT_FEATURE 0x30 35 36 /* Requests / operations */ 37 #define OPCODE_GET_REPORT 0x02 38 39 #define WACOM_QUERY_REPORT 3 40 #define WACOM_QUERY_SIZE 19 41 42 struct wacom_features { 43 int x_max; 44 int y_max; 45 int pressure_max; 46 char fw_version; 47 }; 48 49 struct wacom_i2c { 50 struct i2c_client *client; 51 struct input_dev *input; 52 u8 data[WACOM_QUERY_SIZE]; 53 bool prox; 54 int tool; 55 }; 56 57 static int wacom_query_device(struct i2c_client *client, 58 struct wacom_features *features) 59 { 60 u8 get_query_data_cmd[] = { 61 WACOM_COMMAND_LSB, 62 WACOM_COMMAND_MSB, 63 REPORT_FEATURE | WACOM_QUERY_REPORT, 64 OPCODE_GET_REPORT, 65 WACOM_DATA_LSB, 66 WACOM_DATA_MSB, 67 }; 68 u8 data[WACOM_QUERY_SIZE]; 69 int ret; 70 71 struct i2c_msg msgs[] = { 72 /* Request reading of feature ReportID: 3 (Pen Query Data) */ 73 { 74 .addr = client->addr, 75 .flags = 0, 76 .len = sizeof(get_query_data_cmd), 77 .buf = get_query_data_cmd, 78 }, 79 { 80 .addr = client->addr, 81 .flags = I2C_M_RD, 82 .len = sizeof(data), 83 .buf = data, 84 }, 85 }; 86 87 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 88 if (ret < 0) 89 return ret; 90 if (ret != ARRAY_SIZE(msgs)) 91 return -EIO; 92 93 features->x_max = get_unaligned_le16(&data[3]); 94 features->y_max = get_unaligned_le16(&data[5]); 95 features->pressure_max = get_unaligned_le16(&data[11]); 96 features->fw_version = get_unaligned_le16(&data[13]); 97 98 dev_dbg(&client->dev, 99 "x_max:%d, y_max:%d, pressure:%d, fw:%d\n", 100 features->x_max, features->y_max, 101 features->pressure_max, features->fw_version); 102 103 return 0; 104 } 105 106 static irqreturn_t wacom_i2c_irq(int irq, void *dev_id) 107 { 108 struct wacom_i2c *wac_i2c = dev_id; 109 struct input_dev *input = wac_i2c->input; 110 u8 *data = wac_i2c->data; 111 unsigned int x, y, pressure; 112 unsigned char tsw, f1, f2, ers; 113 int error; 114 115 error = i2c_master_recv(wac_i2c->client, 116 wac_i2c->data, sizeof(wac_i2c->data)); 117 if (error < 0) 118 goto out; 119 120 tsw = data[3] & WACOM_TIP_SWITCH; 121 ers = data[3] & WACOM_ERASER; 122 f1 = data[3] & WACOM_BARREL_SWITCH; 123 f2 = data[3] & WACOM_BARREL_SWITCH_2; 124 x = le16_to_cpup((__le16 *)&data[4]); 125 y = le16_to_cpup((__le16 *)&data[6]); 126 pressure = le16_to_cpup((__le16 *)&data[8]); 127 128 if (!wac_i2c->prox) 129 wac_i2c->tool = (data[3] & (WACOM_ERASER | WACOM_INVERT)) ? 130 BTN_TOOL_RUBBER : BTN_TOOL_PEN; 131 132 wac_i2c->prox = data[3] & WACOM_IN_PROXIMITY; 133 134 input_report_key(input, BTN_TOUCH, tsw || ers); 135 input_report_key(input, wac_i2c->tool, wac_i2c->prox); 136 input_report_key(input, BTN_STYLUS, f1); 137 input_report_key(input, BTN_STYLUS2, f2); 138 input_report_abs(input, ABS_X, x); 139 input_report_abs(input, ABS_Y, y); 140 input_report_abs(input, ABS_PRESSURE, pressure); 141 input_sync(input); 142 143 out: 144 return IRQ_HANDLED; 145 } 146 147 static int wacom_i2c_open(struct input_dev *dev) 148 { 149 struct wacom_i2c *wac_i2c = input_get_drvdata(dev); 150 struct i2c_client *client = wac_i2c->client; 151 152 enable_irq(client->irq); 153 154 return 0; 155 } 156 157 static void wacom_i2c_close(struct input_dev *dev) 158 { 159 struct wacom_i2c *wac_i2c = input_get_drvdata(dev); 160 struct i2c_client *client = wac_i2c->client; 161 162 disable_irq(client->irq); 163 } 164 165 static int wacom_i2c_probe(struct i2c_client *client) 166 { 167 struct device *dev = &client->dev; 168 struct wacom_i2c *wac_i2c; 169 struct input_dev *input; 170 struct wacom_features features = { 0 }; 171 int error; 172 173 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 174 dev_err(dev, "i2c_check_functionality error\n"); 175 return -EIO; 176 } 177 178 error = wacom_query_device(client, &features); 179 if (error) 180 return error; 181 182 wac_i2c = devm_kzalloc(dev, sizeof(*wac_i2c), GFP_KERNEL); 183 if (!wac_i2c) 184 return -ENOMEM; 185 186 wac_i2c->client = client; 187 188 input = devm_input_allocate_device(dev); 189 if (!input) 190 return -ENOMEM; 191 192 wac_i2c->input = input; 193 194 input->name = "Wacom I2C Digitizer"; 195 input->id.bustype = BUS_I2C; 196 input->id.vendor = 0x56a; 197 input->id.version = features.fw_version; 198 input->open = wacom_i2c_open; 199 input->close = wacom_i2c_close; 200 201 input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 202 203 __set_bit(BTN_TOOL_PEN, input->keybit); 204 __set_bit(BTN_TOOL_RUBBER, input->keybit); 205 __set_bit(BTN_STYLUS, input->keybit); 206 __set_bit(BTN_STYLUS2, input->keybit); 207 __set_bit(BTN_TOUCH, input->keybit); 208 209 input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0); 210 input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0); 211 input_set_abs_params(input, ABS_PRESSURE, 212 0, features.pressure_max, 0, 0); 213 214 input_set_drvdata(input, wac_i2c); 215 216 error = devm_request_threaded_irq(dev, client->irq, NULL, wacom_i2c_irq, 217 IRQF_ONESHOT, "wacom_i2c", wac_i2c); 218 if (error) { 219 dev_err(dev, "Failed to request IRQ: %d\n", error); 220 return error; 221 } 222 223 /* Disable the IRQ, we'll enable it in wac_i2c_open() */ 224 disable_irq(client->irq); 225 226 error = input_register_device(wac_i2c->input); 227 if (error) { 228 dev_err(dev, "Failed to register input device: %d\n", error); 229 return error; 230 } 231 232 return 0; 233 } 234 235 static int wacom_i2c_suspend(struct device *dev) 236 { 237 struct i2c_client *client = to_i2c_client(dev); 238 239 disable_irq(client->irq); 240 241 return 0; 242 } 243 244 static int wacom_i2c_resume(struct device *dev) 245 { 246 struct i2c_client *client = to_i2c_client(dev); 247 248 enable_irq(client->irq); 249 250 return 0; 251 } 252 253 static DEFINE_SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume); 254 255 static const struct i2c_device_id wacom_i2c_id[] = { 256 { "WAC_I2C_EMR" }, 257 { } 258 }; 259 MODULE_DEVICE_TABLE(i2c, wacom_i2c_id); 260 261 static struct i2c_driver wacom_i2c_driver = { 262 .driver = { 263 .name = "wacom_i2c", 264 .pm = pm_sleep_ptr(&wacom_i2c_pm), 265 }, 266 267 .probe = wacom_i2c_probe, 268 .id_table = wacom_i2c_id, 269 }; 270 module_i2c_driver(wacom_i2c_driver); 271 272 MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>"); 273 MODULE_DESCRIPTION("WACOM EMR I2C Driver"); 274 MODULE_LICENSE("GPL"); 275