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_CMD_QUERY0 0x04 28 #define WACOM_CMD_QUERY1 0x00 29 #define WACOM_CMD_QUERY2 0x33 30 #define WACOM_CMD_QUERY3 0x02 31 #define WACOM_CMD_THROW0 0x05 32 #define WACOM_CMD_THROW1 0x00 33 #define WACOM_QUERY_SIZE 19 34 35 struct wacom_features { 36 int x_max; 37 int y_max; 38 int pressure_max; 39 char fw_version; 40 }; 41 42 struct wacom_i2c { 43 struct i2c_client *client; 44 struct input_dev *input; 45 u8 data[WACOM_QUERY_SIZE]; 46 bool prox; 47 int tool; 48 }; 49 50 static int wacom_query_device(struct i2c_client *client, 51 struct wacom_features *features) 52 { 53 int ret; 54 u8 cmd1[] = { WACOM_CMD_QUERY0, WACOM_CMD_QUERY1, 55 WACOM_CMD_QUERY2, WACOM_CMD_QUERY3 }; 56 u8 cmd2[] = { WACOM_CMD_THROW0, WACOM_CMD_THROW1 }; 57 u8 data[WACOM_QUERY_SIZE]; 58 struct i2c_msg msgs[] = { 59 { 60 .addr = client->addr, 61 .flags = 0, 62 .len = sizeof(cmd1), 63 .buf = cmd1, 64 }, 65 { 66 .addr = client->addr, 67 .flags = 0, 68 .len = sizeof(cmd2), 69 .buf = cmd2, 70 }, 71 { 72 .addr = client->addr, 73 .flags = I2C_M_RD, 74 .len = sizeof(data), 75 .buf = data, 76 }, 77 }; 78 79 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); 80 if (ret < 0) 81 return ret; 82 if (ret != ARRAY_SIZE(msgs)) 83 return -EIO; 84 85 features->x_max = get_unaligned_le16(&data[3]); 86 features->y_max = get_unaligned_le16(&data[5]); 87 features->pressure_max = get_unaligned_le16(&data[11]); 88 features->fw_version = get_unaligned_le16(&data[13]); 89 90 dev_dbg(&client->dev, 91 "x_max:%d, y_max:%d, pressure:%d, fw:%d\n", 92 features->x_max, features->y_max, 93 features->pressure_max, features->fw_version); 94 95 return 0; 96 } 97 98 static irqreturn_t wacom_i2c_irq(int irq, void *dev_id) 99 { 100 struct wacom_i2c *wac_i2c = dev_id; 101 struct input_dev *input = wac_i2c->input; 102 u8 *data = wac_i2c->data; 103 unsigned int x, y, pressure; 104 unsigned char tsw, f1, f2, ers; 105 int error; 106 107 error = i2c_master_recv(wac_i2c->client, 108 wac_i2c->data, sizeof(wac_i2c->data)); 109 if (error < 0) 110 goto out; 111 112 tsw = data[3] & WACOM_TIP_SWITCH; 113 ers = data[3] & WACOM_ERASER; 114 f1 = data[3] & WACOM_BARREL_SWITCH; 115 f2 = data[3] & WACOM_BARREL_SWITCH_2; 116 x = le16_to_cpup((__le16 *)&data[4]); 117 y = le16_to_cpup((__le16 *)&data[6]); 118 pressure = le16_to_cpup((__le16 *)&data[8]); 119 120 if (!wac_i2c->prox) 121 wac_i2c->tool = (data[3] & (WACOM_ERASER | WACOM_INVERT)) ? 122 BTN_TOOL_RUBBER : BTN_TOOL_PEN; 123 124 wac_i2c->prox = data[3] & WACOM_IN_PROXIMITY; 125 126 input_report_key(input, BTN_TOUCH, tsw || ers); 127 input_report_key(input, wac_i2c->tool, wac_i2c->prox); 128 input_report_key(input, BTN_STYLUS, f1); 129 input_report_key(input, BTN_STYLUS2, f2); 130 input_report_abs(input, ABS_X, x); 131 input_report_abs(input, ABS_Y, y); 132 input_report_abs(input, ABS_PRESSURE, pressure); 133 input_sync(input); 134 135 out: 136 return IRQ_HANDLED; 137 } 138 139 static int wacom_i2c_open(struct input_dev *dev) 140 { 141 struct wacom_i2c *wac_i2c = input_get_drvdata(dev); 142 struct i2c_client *client = wac_i2c->client; 143 144 enable_irq(client->irq); 145 146 return 0; 147 } 148 149 static void wacom_i2c_close(struct input_dev *dev) 150 { 151 struct wacom_i2c *wac_i2c = input_get_drvdata(dev); 152 struct i2c_client *client = wac_i2c->client; 153 154 disable_irq(client->irq); 155 } 156 157 static int wacom_i2c_probe(struct i2c_client *client, 158 const struct i2c_device_id *id) 159 { 160 struct device *dev = &client->dev; 161 struct wacom_i2c *wac_i2c; 162 struct input_dev *input; 163 struct wacom_features features = { 0 }; 164 int error; 165 166 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 167 dev_err(dev, "i2c_check_functionality error\n"); 168 return -EIO; 169 } 170 171 error = wacom_query_device(client, &features); 172 if (error) 173 return error; 174 175 wac_i2c = devm_kzalloc(dev, sizeof(*wac_i2c), GFP_KERNEL); 176 if (!wac_i2c) 177 return -ENOMEM; 178 179 wac_i2c->client = client; 180 181 input = devm_input_allocate_device(dev); 182 if (!input) 183 return -ENOMEM; 184 185 wac_i2c->input = input; 186 187 input->name = "Wacom I2C Digitizer"; 188 input->id.bustype = BUS_I2C; 189 input->id.vendor = 0x56a; 190 input->id.version = features.fw_version; 191 input->open = wacom_i2c_open; 192 input->close = wacom_i2c_close; 193 194 input->evbit[0] |= BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 195 196 __set_bit(BTN_TOOL_PEN, input->keybit); 197 __set_bit(BTN_TOOL_RUBBER, input->keybit); 198 __set_bit(BTN_STYLUS, input->keybit); 199 __set_bit(BTN_STYLUS2, input->keybit); 200 __set_bit(BTN_TOUCH, input->keybit); 201 202 input_set_abs_params(input, ABS_X, 0, features.x_max, 0, 0); 203 input_set_abs_params(input, ABS_Y, 0, features.y_max, 0, 0); 204 input_set_abs_params(input, ABS_PRESSURE, 205 0, features.pressure_max, 0, 0); 206 207 input_set_drvdata(input, wac_i2c); 208 209 error = devm_request_threaded_irq(dev, client->irq, NULL, wacom_i2c_irq, 210 IRQF_ONESHOT, "wacom_i2c", wac_i2c); 211 if (error) { 212 dev_err(dev, "Failed to request IRQ: %d\n", error); 213 return error; 214 } 215 216 /* Disable the IRQ, we'll enable it in wac_i2c_open() */ 217 disable_irq(client->irq); 218 219 error = input_register_device(wac_i2c->input); 220 if (error) { 221 dev_err(dev, "Failed to register input device: %d\n", error); 222 return error; 223 } 224 225 return 0; 226 } 227 228 static int __maybe_unused wacom_i2c_suspend(struct device *dev) 229 { 230 struct i2c_client *client = to_i2c_client(dev); 231 232 disable_irq(client->irq); 233 234 return 0; 235 } 236 237 static int __maybe_unused wacom_i2c_resume(struct device *dev) 238 { 239 struct i2c_client *client = to_i2c_client(dev); 240 241 enable_irq(client->irq); 242 243 return 0; 244 } 245 246 static SIMPLE_DEV_PM_OPS(wacom_i2c_pm, wacom_i2c_suspend, wacom_i2c_resume); 247 248 static const struct i2c_device_id wacom_i2c_id[] = { 249 { "WAC_I2C_EMR", 0 }, 250 { }, 251 }; 252 MODULE_DEVICE_TABLE(i2c, wacom_i2c_id); 253 254 static struct i2c_driver wacom_i2c_driver = { 255 .driver = { 256 .name = "wacom_i2c", 257 .pm = &wacom_i2c_pm, 258 }, 259 260 .probe = wacom_i2c_probe, 261 .id_table = wacom_i2c_id, 262 }; 263 module_i2c_driver(wacom_i2c_driver); 264 265 MODULE_AUTHOR("Tatsunosuke Tobita <tobita.tatsunosuke@wacom.co.jp>"); 266 MODULE_DESCRIPTION("WACOM EMR I2C Driver"); 267 MODULE_LICENSE("GPL"); 268