1 /* 2 * Copyright (C) 2016, Jelle van der Waa <jelle@vdwaa.nl> 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License as published by the Free 6 * Software Foundation; either version 2 of the License, or (at your option) 7 * any later version. 8 * 9 * This program is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 12 * more details. 13 */ 14 15 #include <linux/delay.h> 16 #include <linux/i2c.h> 17 #include <linux/input.h> 18 #include <linux/input/mt.h> 19 #include <linux/input/touchscreen.h> 20 #include <linux/interrupt.h> 21 #include <linux/module.h> 22 #include <linux/regulator/consumer.h> 23 #include <asm/unaligned.h> 24 25 #define ZET6223_MAX_FINGERS 16 26 #define ZET6223_MAX_PKT_SIZE (3 + 4 * ZET6223_MAX_FINGERS) 27 28 #define ZET6223_CMD_INFO 0xB2 29 #define ZET6223_CMD_INFO_LENGTH 17 30 #define ZET6223_VALID_PACKET 0x3c 31 32 #define ZET6223_POWER_ON_DELAY_MSEC 30 33 34 struct zet6223_ts { 35 struct i2c_client *client; 36 struct input_dev *input; 37 struct regulator *vcc; 38 struct regulator *vio; 39 struct touchscreen_properties prop; 40 struct regulator_bulk_data supplies[2]; 41 u16 max_x; 42 u16 max_y; 43 u8 fingernum; 44 }; 45 46 static int zet6223_start(struct input_dev *dev) 47 { 48 struct zet6223_ts *ts = input_get_drvdata(dev); 49 50 enable_irq(ts->client->irq); 51 52 return 0; 53 } 54 55 static void zet6223_stop(struct input_dev *dev) 56 { 57 struct zet6223_ts *ts = input_get_drvdata(dev); 58 59 disable_irq(ts->client->irq); 60 } 61 62 static irqreturn_t zet6223_irq(int irq, void *dev_id) 63 { 64 struct zet6223_ts *ts = dev_id; 65 u16 finger_bits; 66 67 /* 68 * First 3 bytes are an identifier, two bytes of finger data. 69 * X, Y data per finger is 4 bytes. 70 */ 71 u8 bufsize = 3 + 4 * ts->fingernum; 72 u8 buf[ZET6223_MAX_PKT_SIZE]; 73 int i; 74 int ret; 75 int error; 76 77 ret = i2c_master_recv(ts->client, buf, bufsize); 78 if (ret != bufsize) { 79 error = ret < 0 ? ret : -EIO; 80 dev_err_ratelimited(&ts->client->dev, 81 "Error reading input data: %d\n", error); 82 return IRQ_HANDLED; 83 } 84 85 if (buf[0] != ZET6223_VALID_PACKET) 86 return IRQ_HANDLED; 87 88 finger_bits = get_unaligned_be16(buf + 1); 89 for (i = 0; i < ts->fingernum; i++) { 90 if (!(finger_bits & BIT(15 - i))) 91 continue; 92 93 input_mt_slot(ts->input, i); 94 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true); 95 input_event(ts->input, EV_ABS, ABS_MT_POSITION_X, 96 ((buf[i + 3] >> 4) << 8) + buf[i + 4]); 97 input_event(ts->input, EV_ABS, ABS_MT_POSITION_Y, 98 ((buf[i + 3] & 0xF) << 8) + buf[i + 5]); 99 } 100 101 input_mt_sync_frame(ts->input); 102 input_sync(ts->input); 103 104 return IRQ_HANDLED; 105 } 106 107 static void zet6223_power_off(void *_ts) 108 { 109 struct zet6223_ts *ts = _ts; 110 111 regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies); 112 } 113 114 static int zet6223_power_on(struct zet6223_ts *ts) 115 { 116 struct device *dev = &ts->client->dev; 117 int error; 118 119 ts->supplies[0].supply = "vio"; 120 ts->supplies[1].supply = "vcc"; 121 122 error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies), 123 ts->supplies); 124 if (error) 125 return error; 126 127 error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies); 128 if (error) 129 return error; 130 131 msleep(ZET6223_POWER_ON_DELAY_MSEC); 132 133 error = devm_add_action_or_reset(dev, zet6223_power_off, ts); 134 if (error) { 135 dev_err(dev, "failed to install poweroff action: %d\n", error); 136 return error; 137 } 138 139 return 0; 140 } 141 142 static int zet6223_query_device(struct zet6223_ts *ts) 143 { 144 u8 buf[ZET6223_CMD_INFO_LENGTH]; 145 u8 cmd = ZET6223_CMD_INFO; 146 int ret; 147 int error; 148 149 ret = i2c_master_send(ts->client, &cmd, sizeof(cmd)); 150 if (ret != sizeof(cmd)) { 151 error = ret < 0 ? ret : -EIO; 152 dev_err(&ts->client->dev, 153 "touchpanel info cmd failed: %d\n", error); 154 return error; 155 } 156 157 ret = i2c_master_recv(ts->client, buf, sizeof(buf)); 158 if (ret != sizeof(buf)) { 159 error = ret < 0 ? ret : -EIO; 160 dev_err(&ts->client->dev, 161 "failed to retrieve touchpanel info: %d\n", error); 162 return error; 163 } 164 165 ts->fingernum = buf[15] & 0x7F; 166 if (ts->fingernum > ZET6223_MAX_FINGERS) { 167 dev_warn(&ts->client->dev, 168 "touchpanel reports %d fingers, limiting to %d\n", 169 ts->fingernum, ZET6223_MAX_FINGERS); 170 ts->fingernum = ZET6223_MAX_FINGERS; 171 } 172 173 ts->max_x = get_unaligned_le16(&buf[8]); 174 ts->max_y = get_unaligned_le16(&buf[10]); 175 176 return 0; 177 } 178 179 static int zet6223_probe(struct i2c_client *client, 180 const struct i2c_device_id *id) 181 { 182 struct device *dev = &client->dev; 183 struct zet6223_ts *ts; 184 struct input_dev *input; 185 int error; 186 187 if (!client->irq) { 188 dev_err(dev, "no irq specified\n"); 189 return -EINVAL; 190 } 191 192 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); 193 if (!ts) 194 return -ENOMEM; 195 196 ts->client = client; 197 198 error = zet6223_power_on(ts); 199 if (error) 200 return error; 201 202 error = zet6223_query_device(ts); 203 if (error) 204 return error; 205 206 ts->input = input = devm_input_allocate_device(dev); 207 if (!input) 208 return -ENOMEM; 209 210 input_set_drvdata(input, ts); 211 212 input->name = client->name; 213 input->id.bustype = BUS_I2C; 214 input->open = zet6223_start; 215 input->close = zet6223_stop; 216 217 input_set_abs_params(input, ABS_MT_POSITION_X, 0, ts->max_x, 0, 0); 218 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, ts->max_y, 0, 0); 219 220 touchscreen_parse_properties(input, true, &ts->prop); 221 222 error = input_mt_init_slots(input, ts->fingernum, 223 INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED); 224 if (error) 225 return error; 226 227 error = devm_request_threaded_irq(dev, client->irq, NULL, zet6223_irq, 228 IRQF_ONESHOT, client->name, ts); 229 if (error) { 230 dev_err(dev, "failed to request irq %d: %d\n", 231 client->irq, error); 232 return error; 233 } 234 235 zet6223_stop(input); 236 237 error = input_register_device(input); 238 if (error) 239 return error; 240 241 return 0; 242 } 243 244 static const struct of_device_id zet6223_of_match[] = { 245 { .compatible = "zeitec,zet6223" }, 246 { } 247 }; 248 MODULE_DEVICE_TABLE(of, zet6223_of_match); 249 250 static const struct i2c_device_id zet6223_id[] = { 251 { "zet6223", 0}, 252 { } 253 }; 254 MODULE_DEVICE_TABLE(i2c, zet6223_id); 255 256 static struct i2c_driver zet6223_driver = { 257 .driver = { 258 .name = "zet6223", 259 .of_match_table = zet6223_of_match, 260 }, 261 .probe = zet6223_probe, 262 .id_table = zet6223_id 263 }; 264 module_i2c_driver(zet6223_driver); 265 266 MODULE_AUTHOR("Jelle van der Waa <jelle@vdwaa.nl>"); 267 MODULE_DESCRIPTION("ZEITEC zet622x I2C touchscreen driver"); 268 MODULE_LICENSE("GPL"); 269