Jean Delvare | b9cdad7 | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Driver for the TAOS evaluation modules |
| 3 | * These devices include an I2C master which can be controlled over the |
| 4 | * serial port. |
| 5 | * |
| 6 | * Copyright (C) 2007 Jean Delvare <khali@linux-fr.org> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; version 2 of the License. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 20 | */ |
| 21 | |
| 22 | #include <linux/delay.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/slab.h> |
| 25 | #include <linux/interrupt.h> |
| 26 | #include <linux/input.h> |
| 27 | #include <linux/serio.h> |
| 28 | #include <linux/init.h> |
| 29 | #include <linux/i2c.h> |
| 30 | |
| 31 | #define TAOS_BUFFER_SIZE 63 |
| 32 | |
| 33 | #define TAOS_STATE_INIT 0 |
| 34 | #define TAOS_STATE_IDLE 1 |
| 35 | #define TAOS_STATE_SEND 2 |
| 36 | #define TAOS_STATE_RECV 3 |
| 37 | |
| 38 | #define TAOS_CMD_RESET 0x12 |
| 39 | |
| 40 | static DECLARE_WAIT_QUEUE_HEAD(wq); |
| 41 | |
| 42 | struct taos_data { |
| 43 | struct i2c_adapter adapter; |
| 44 | struct i2c_client *client; |
| 45 | int state; |
| 46 | u8 addr; /* last used address */ |
| 47 | unsigned char buffer[TAOS_BUFFER_SIZE]; |
| 48 | unsigned int pos; /* position inside the buffer */ |
| 49 | }; |
| 50 | |
| 51 | /* TAOS TSL2550 EVM */ |
| 52 | static struct i2c_board_info tsl2550_info = { |
| 53 | I2C_BOARD_INFO("tsl2550", 0x39), |
Jean Delvare | b9cdad7 | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 54 | }; |
| 55 | |
| 56 | /* Instantiate i2c devices based on the adapter name */ |
| 57 | static struct i2c_client *taos_instantiate_device(struct i2c_adapter *adapter) |
| 58 | { |
| 59 | if (!strncmp(adapter->name, "TAOS TSL2550 EVM", 16)) { |
| 60 | dev_info(&adapter->dev, "Instantiating device %s at 0x%02x\n", |
Jean Delvare | 3760f73 | 2008-04-29 23:11:40 +0200 | [diff] [blame] | 61 | tsl2550_info.type, tsl2550_info.addr); |
Jean Delvare | b9cdad7 | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 62 | return i2c_new_device(adapter, &tsl2550_info); |
| 63 | } |
| 64 | |
| 65 | return NULL; |
| 66 | } |
| 67 | |
| 68 | static int taos_smbus_xfer(struct i2c_adapter *adapter, u16 addr, |
| 69 | unsigned short flags, char read_write, u8 command, |
| 70 | int size, union i2c_smbus_data *data) |
| 71 | { |
| 72 | struct serio *serio = adapter->algo_data; |
| 73 | struct taos_data *taos = serio_get_drvdata(serio); |
| 74 | char *p; |
| 75 | |
| 76 | /* Encode our transaction. "@" is for the device address, "$" for the |
| 77 | SMBus command and "#" for the data. */ |
| 78 | p = taos->buffer; |
| 79 | |
| 80 | /* The device remembers the last used address, no need to send it |
| 81 | again if it's the same */ |
| 82 | if (addr != taos->addr) |
| 83 | p += sprintf(p, "@%02X", addr); |
| 84 | |
| 85 | switch (size) { |
| 86 | case I2C_SMBUS_BYTE: |
| 87 | if (read_write == I2C_SMBUS_WRITE) |
| 88 | sprintf(p, "$#%02X", command); |
| 89 | else |
| 90 | sprintf(p, "$"); |
| 91 | break; |
| 92 | case I2C_SMBUS_BYTE_DATA: |
| 93 | if (read_write == I2C_SMBUS_WRITE) |
| 94 | sprintf(p, "$%02X#%02X", command, data->byte); |
| 95 | else |
| 96 | sprintf(p, "$%02X", command); |
| 97 | break; |
| 98 | default: |
Jean Delvare | ac7fc4f | 2008-07-14 22:38:25 +0200 | [diff] [blame] | 99 | dev_warn(&adapter->dev, "Unsupported transaction %d\n", size); |
| 100 | return -EOPNOTSUPP; |
Jean Delvare | b9cdad7 | 2007-07-12 14:12:31 +0200 | [diff] [blame] | 101 | } |
| 102 | |
| 103 | /* Send the transaction to the TAOS EVM */ |
| 104 | dev_dbg(&adapter->dev, "Command buffer: %s\n", taos->buffer); |
| 105 | taos->pos = 0; |
| 106 | taos->state = TAOS_STATE_SEND; |
| 107 | serio_write(serio, taos->buffer[0]); |
| 108 | wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE, |
| 109 | msecs_to_jiffies(250)); |
| 110 | if (taos->state != TAOS_STATE_IDLE) { |
| 111 | dev_err(&adapter->dev, "Transaction failed " |
| 112 | "(state=%d, pos=%d)\n", taos->state, taos->pos); |
| 113 | taos->addr = 0; |
| 114 | return -EIO; |
| 115 | } |
| 116 | taos->addr = addr; |
| 117 | |
| 118 | /* Start the transaction and read the answer */ |
| 119 | taos->pos = 0; |
| 120 | taos->state = TAOS_STATE_RECV; |
| 121 | serio_write(serio, read_write == I2C_SMBUS_WRITE ? '>' : '<'); |
| 122 | wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE, |
| 123 | msecs_to_jiffies(150)); |
| 124 | if (taos->state != TAOS_STATE_IDLE |
| 125 | || taos->pos != 6) { |
| 126 | dev_err(&adapter->dev, "Transaction timeout (pos=%d)\n", |
| 127 | taos->pos); |
| 128 | return -EIO; |
| 129 | } |
| 130 | dev_dbg(&adapter->dev, "Answer buffer: %s\n", taos->buffer); |
| 131 | |
| 132 | /* Interpret the returned string */ |
| 133 | p = taos->buffer + 2; |
| 134 | p[3] = '\0'; |
| 135 | if (!strcmp(p, "NAK")) |
| 136 | return -ENODEV; |
| 137 | |
| 138 | if (read_write == I2C_SMBUS_WRITE) { |
| 139 | if (!strcmp(p, "ACK")) |
| 140 | return 0; |
| 141 | } else { |
| 142 | if (p[0] == 'x') { |
| 143 | data->byte = simple_strtol(p + 1, NULL, 16); |
| 144 | return 0; |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | return -EIO; |
| 149 | } |
| 150 | |
| 151 | static u32 taos_smbus_func(struct i2c_adapter *adapter) |
| 152 | { |
| 153 | return I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA; |
| 154 | } |
| 155 | |
| 156 | static const struct i2c_algorithm taos_algorithm = { |
| 157 | .smbus_xfer = taos_smbus_xfer, |
| 158 | .functionality = taos_smbus_func, |
| 159 | }; |
| 160 | |
| 161 | static irqreturn_t taos_interrupt(struct serio *serio, unsigned char data, |
| 162 | unsigned int flags) |
| 163 | { |
| 164 | struct taos_data *taos = serio_get_drvdata(serio); |
| 165 | |
| 166 | switch (taos->state) { |
| 167 | case TAOS_STATE_INIT: |
| 168 | taos->buffer[taos->pos++] = data; |
| 169 | if (data == ':' |
| 170 | || taos->pos == TAOS_BUFFER_SIZE - 1) { |
| 171 | taos->buffer[taos->pos] = '\0'; |
| 172 | taos->state = TAOS_STATE_IDLE; |
| 173 | wake_up_interruptible(&wq); |
| 174 | } |
| 175 | break; |
| 176 | case TAOS_STATE_SEND: |
| 177 | if (taos->buffer[++taos->pos]) |
| 178 | serio_write(serio, taos->buffer[taos->pos]); |
| 179 | else { |
| 180 | taos->state = TAOS_STATE_IDLE; |
| 181 | wake_up_interruptible(&wq); |
| 182 | } |
| 183 | break; |
| 184 | case TAOS_STATE_RECV: |
| 185 | taos->buffer[taos->pos++] = data; |
| 186 | if (data == ']') { |
| 187 | taos->buffer[taos->pos] = '\0'; |
| 188 | taos->state = TAOS_STATE_IDLE; |
| 189 | wake_up_interruptible(&wq); |
| 190 | } |
| 191 | break; |
| 192 | } |
| 193 | |
| 194 | return IRQ_HANDLED; |
| 195 | } |
| 196 | |
| 197 | /* Extract the adapter name from the buffer received after reset. |
| 198 | The buffer is modified and a pointer inside the buffer is returned. */ |
| 199 | static char *taos_adapter_name(char *buffer) |
| 200 | { |
| 201 | char *start, *end; |
| 202 | |
| 203 | start = strstr(buffer, "TAOS "); |
| 204 | if (!start) |
| 205 | return NULL; |
| 206 | |
| 207 | end = strchr(start, '\r'); |
| 208 | if (!end) |
| 209 | return NULL; |
| 210 | *end = '\0'; |
| 211 | |
| 212 | return start; |
| 213 | } |
| 214 | |
| 215 | static int taos_connect(struct serio *serio, struct serio_driver *drv) |
| 216 | { |
| 217 | struct taos_data *taos; |
| 218 | struct i2c_adapter *adapter; |
| 219 | char *name; |
| 220 | int err; |
| 221 | |
| 222 | taos = kzalloc(sizeof(struct taos_data), GFP_KERNEL); |
| 223 | if (!taos) { |
| 224 | err = -ENOMEM; |
| 225 | goto exit; |
| 226 | } |
| 227 | taos->state = TAOS_STATE_INIT; |
| 228 | serio_set_drvdata(serio, taos); |
| 229 | |
| 230 | err = serio_open(serio, drv); |
| 231 | if (err) |
| 232 | goto exit_kfree; |
| 233 | |
| 234 | adapter = &taos->adapter; |
| 235 | adapter->owner = THIS_MODULE; |
| 236 | adapter->algo = &taos_algorithm; |
| 237 | adapter->algo_data = serio; |
| 238 | adapter->dev.parent = &serio->dev; |
| 239 | |
| 240 | /* Reset the TAOS evaluation module to identify it */ |
| 241 | serio_write(serio, TAOS_CMD_RESET); |
| 242 | wait_event_interruptible_timeout(wq, taos->state == TAOS_STATE_IDLE, |
| 243 | msecs_to_jiffies(2000)); |
| 244 | |
| 245 | if (taos->state != TAOS_STATE_IDLE) { |
| 246 | err = -ENODEV; |
| 247 | dev_dbg(&serio->dev, "TAOS EVM reset failed (state=%d, " |
| 248 | "pos=%d)\n", taos->state, taos->pos); |
| 249 | goto exit_close; |
| 250 | } |
| 251 | |
| 252 | name = taos_adapter_name(taos->buffer); |
| 253 | if (!name) { |
| 254 | err = -ENODEV; |
| 255 | dev_err(&serio->dev, "TAOS EVM identification failed\n"); |
| 256 | goto exit_close; |
| 257 | } |
| 258 | strlcpy(adapter->name, name, sizeof(adapter->name)); |
| 259 | |
| 260 | err = i2c_add_adapter(adapter); |
| 261 | if (err) |
| 262 | goto exit_close; |
| 263 | dev_dbg(&serio->dev, "Connected to TAOS EVM\n"); |
| 264 | |
| 265 | taos->client = taos_instantiate_device(adapter); |
| 266 | return 0; |
| 267 | |
| 268 | exit_close: |
| 269 | serio_close(serio); |
| 270 | exit_kfree: |
| 271 | serio_set_drvdata(serio, NULL); |
| 272 | kfree(taos); |
| 273 | exit: |
| 274 | return err; |
| 275 | } |
| 276 | |
| 277 | static void taos_disconnect(struct serio *serio) |
| 278 | { |
| 279 | struct taos_data *taos = serio_get_drvdata(serio); |
| 280 | |
| 281 | if (taos->client) |
| 282 | i2c_unregister_device(taos->client); |
| 283 | i2c_del_adapter(&taos->adapter); |
| 284 | serio_close(serio); |
| 285 | serio_set_drvdata(serio, NULL); |
| 286 | kfree(taos); |
| 287 | |
| 288 | dev_dbg(&serio->dev, "Disconnected from TAOS EVM\n"); |
| 289 | } |
| 290 | |
| 291 | static struct serio_device_id taos_serio_ids[] = { |
| 292 | { |
| 293 | .type = SERIO_RS232, |
| 294 | .proto = SERIO_TAOSEVM, |
| 295 | .id = SERIO_ANY, |
| 296 | .extra = SERIO_ANY, |
| 297 | }, |
| 298 | { 0 } |
| 299 | }; |
| 300 | MODULE_DEVICE_TABLE(serio, taos_serio_ids); |
| 301 | |
| 302 | static struct serio_driver taos_drv = { |
| 303 | .driver = { |
| 304 | .name = "taos-evm", |
| 305 | }, |
| 306 | .description = "TAOS evaluation module driver", |
| 307 | .id_table = taos_serio_ids, |
| 308 | .connect = taos_connect, |
| 309 | .disconnect = taos_disconnect, |
| 310 | .interrupt = taos_interrupt, |
| 311 | }; |
| 312 | |
| 313 | static int __init taos_init(void) |
| 314 | { |
| 315 | return serio_register_driver(&taos_drv); |
| 316 | } |
| 317 | |
| 318 | static void __exit taos_exit(void) |
| 319 | { |
| 320 | serio_unregister_driver(&taos_drv); |
| 321 | } |
| 322 | |
| 323 | MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); |
| 324 | MODULE_DESCRIPTION("TAOS evaluation module driver"); |
| 325 | MODULE_LICENSE("GPL"); |
| 326 | |
| 327 | module_init(taos_init); |
| 328 | module_exit(taos_exit); |