1 /* 2 * Fintek F81232 USB to serial adaptor driver 3 * 4 * Copyright (C) 2012 Greg Kroah-Hartman (gregkh@linuxfoundation.org) 5 * Copyright (C) 2012 Linux Foundation 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License version 2 as published by 9 * the Free Software Foundation. 10 * 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/errno.h> 15 #include <linux/init.h> 16 #include <linux/slab.h> 17 #include <linux/tty.h> 18 #include <linux/tty_driver.h> 19 #include <linux/tty_flip.h> 20 #include <linux/serial.h> 21 #include <linux/module.h> 22 #include <linux/moduleparam.h> 23 #include <linux/spinlock.h> 24 #include <linux/uaccess.h> 25 #include <linux/usb.h> 26 #include <linux/usb/serial.h> 27 28 static bool debug; 29 30 static const struct usb_device_id id_table[] = { 31 { USB_DEVICE(0x1934, 0x0706) }, 32 { } /* Terminating entry */ 33 }; 34 MODULE_DEVICE_TABLE(usb, id_table); 35 36 #define CONTROL_DTR 0x01 37 #define CONTROL_RTS 0x02 38 39 #define UART_STATE 0x08 40 #define UART_STATE_TRANSIENT_MASK 0x74 41 #define UART_DCD 0x01 42 #define UART_DSR 0x02 43 #define UART_BREAK_ERROR 0x04 44 #define UART_RING 0x08 45 #define UART_FRAME_ERROR 0x10 46 #define UART_PARITY_ERROR 0x20 47 #define UART_OVERRUN_ERROR 0x40 48 #define UART_CTS 0x80 49 50 struct f81232_private { 51 spinlock_t lock; 52 wait_queue_head_t delta_msr_wait; 53 u8 line_control; 54 u8 line_status; 55 }; 56 57 static void f81232_update_line_status(struct usb_serial_port *port, 58 unsigned char *data, 59 unsigned int actual_length) 60 { 61 } 62 63 static void f81232_read_int_callback(struct urb *urb) 64 { 65 struct usb_serial_port *port = urb->context; 66 unsigned char *data = urb->transfer_buffer; 67 unsigned int actual_length = urb->actual_length; 68 int status = urb->status; 69 int retval; 70 71 switch (status) { 72 case 0: 73 /* success */ 74 break; 75 case -ECONNRESET: 76 case -ENOENT: 77 case -ESHUTDOWN: 78 /* this urb is terminated, clean up */ 79 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n", 80 __func__, status); 81 return; 82 default: 83 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n", 84 __func__, status); 85 goto exit; 86 } 87 88 usb_serial_debug_data(debug, &port->dev, __func__, 89 urb->actual_length, urb->transfer_buffer); 90 91 f81232_update_line_status(port, data, actual_length); 92 93 exit: 94 retval = usb_submit_urb(urb, GFP_ATOMIC); 95 if (retval) 96 dev_err(&urb->dev->dev, 97 "%s - usb_submit_urb failed with result %d\n", 98 __func__, retval); 99 } 100 101 static void f81232_process_read_urb(struct urb *urb) 102 { 103 struct usb_serial_port *port = urb->context; 104 struct f81232_private *priv = usb_get_serial_port_data(port); 105 struct tty_struct *tty; 106 unsigned char *data = urb->transfer_buffer; 107 char tty_flag = TTY_NORMAL; 108 unsigned long flags; 109 u8 line_status; 110 int i; 111 112 /* update line status */ 113 spin_lock_irqsave(&priv->lock, flags); 114 line_status = priv->line_status; 115 priv->line_status &= ~UART_STATE_TRANSIENT_MASK; 116 spin_unlock_irqrestore(&priv->lock, flags); 117 wake_up_interruptible(&priv->delta_msr_wait); 118 119 if (!urb->actual_length) 120 return; 121 122 tty = tty_port_tty_get(&port->port); 123 if (!tty) 124 return; 125 126 /* break takes precedence over parity, */ 127 /* which takes precedence over framing errors */ 128 if (line_status & UART_BREAK_ERROR) 129 tty_flag = TTY_BREAK; 130 else if (line_status & UART_PARITY_ERROR) 131 tty_flag = TTY_PARITY; 132 else if (line_status & UART_FRAME_ERROR) 133 tty_flag = TTY_FRAME; 134 dev_dbg(&port->dev, "%s - tty_flag = %d\n", __func__, tty_flag); 135 136 /* overrun is special, not associated with a char */ 137 if (line_status & UART_OVERRUN_ERROR) 138 tty_insert_flip_char(tty, 0, TTY_OVERRUN); 139 140 if (port->port.console && port->sysrq) { 141 for (i = 0; i < urb->actual_length; ++i) 142 if (!usb_serial_handle_sysrq_char(port, data[i])) 143 tty_insert_flip_char(tty, data[i], tty_flag); 144 } else { 145 tty_insert_flip_string_fixed_flag(tty, data, tty_flag, 146 urb->actual_length); 147 } 148 149 tty_flip_buffer_push(tty); 150 tty_kref_put(tty); 151 } 152 153 static int set_control_lines(struct usb_device *dev, u8 value) 154 { 155 /* FIXME - Stubbed out for now */ 156 return 0; 157 } 158 159 static void f81232_break_ctl(struct tty_struct *tty, int break_state) 160 { 161 /* FIXME - Stubbed out for now */ 162 163 /* 164 * break_state = -1 to turn on break, and 0 to turn off break 165 * see drivers/char/tty_io.c to see it used. 166 * last_set_data_urb_value NEVER has the break bit set in it. 167 */ 168 } 169 170 static void f81232_set_termios(struct tty_struct *tty, 171 struct usb_serial_port *port, struct ktermios *old_termios) 172 { 173 /* FIXME - Stubbed out for now */ 174 175 /* Don't change anything if nothing has changed */ 176 if (!tty_termios_hw_change(tty->termios, old_termios)) 177 return; 178 179 /* Do the real work here... */ 180 } 181 182 static int f81232_tiocmget(struct tty_struct *tty) 183 { 184 /* FIXME - Stubbed out for now */ 185 return 0; 186 } 187 188 static int f81232_tiocmset(struct tty_struct *tty, 189 unsigned int set, unsigned int clear) 190 { 191 /* FIXME - Stubbed out for now */ 192 return 0; 193 } 194 195 static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port) 196 { 197 struct ktermios tmp_termios; 198 int result; 199 200 /* Setup termios */ 201 if (tty) 202 f81232_set_termios(tty, port, &tmp_termios); 203 204 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); 205 if (result) { 206 dev_err(&port->dev, "%s - failed submitting interrupt urb," 207 " error %d\n", __func__, result); 208 return result; 209 } 210 211 result = usb_serial_generic_open(tty, port); 212 if (result) { 213 usb_kill_urb(port->interrupt_in_urb); 214 return result; 215 } 216 217 port->port.drain_delay = 256; 218 return 0; 219 } 220 221 static void f81232_close(struct usb_serial_port *port) 222 { 223 usb_serial_generic_close(port); 224 usb_kill_urb(port->interrupt_in_urb); 225 } 226 227 static void f81232_dtr_rts(struct usb_serial_port *port, int on) 228 { 229 struct f81232_private *priv = usb_get_serial_port_data(port); 230 unsigned long flags; 231 u8 control; 232 233 spin_lock_irqsave(&priv->lock, flags); 234 /* Change DTR and RTS */ 235 if (on) 236 priv->line_control |= (CONTROL_DTR | CONTROL_RTS); 237 else 238 priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS); 239 control = priv->line_control; 240 spin_unlock_irqrestore(&priv->lock, flags); 241 set_control_lines(port->serial->dev, control); 242 } 243 244 static int f81232_carrier_raised(struct usb_serial_port *port) 245 { 246 struct f81232_private *priv = usb_get_serial_port_data(port); 247 if (priv->line_status & UART_DCD) 248 return 1; 249 return 0; 250 } 251 252 static int wait_modem_info(struct usb_serial_port *port, unsigned int arg) 253 { 254 struct f81232_private *priv = usb_get_serial_port_data(port); 255 unsigned long flags; 256 unsigned int prevstatus; 257 unsigned int status; 258 unsigned int changed; 259 260 spin_lock_irqsave(&priv->lock, flags); 261 prevstatus = priv->line_status; 262 spin_unlock_irqrestore(&priv->lock, flags); 263 264 while (1) { 265 interruptible_sleep_on(&priv->delta_msr_wait); 266 /* see if a signal did it */ 267 if (signal_pending(current)) 268 return -ERESTARTSYS; 269 270 spin_lock_irqsave(&priv->lock, flags); 271 status = priv->line_status; 272 spin_unlock_irqrestore(&priv->lock, flags); 273 274 changed = prevstatus ^ status; 275 276 if (((arg & TIOCM_RNG) && (changed & UART_RING)) || 277 ((arg & TIOCM_DSR) && (changed & UART_DSR)) || 278 ((arg & TIOCM_CD) && (changed & UART_DCD)) || 279 ((arg & TIOCM_CTS) && (changed & UART_CTS))) { 280 return 0; 281 } 282 prevstatus = status; 283 } 284 /* NOTREACHED */ 285 return 0; 286 } 287 288 static int f81232_ioctl(struct tty_struct *tty, 289 unsigned int cmd, unsigned long arg) 290 { 291 struct serial_struct ser; 292 struct usb_serial_port *port = tty->driver_data; 293 294 dev_dbg(&port->dev, "%s (%d) cmd = 0x%04x\n", __func__, 295 port->number, cmd); 296 297 switch (cmd) { 298 case TIOCGSERIAL: 299 memset(&ser, 0, sizeof ser); 300 ser.type = PORT_16654; 301 ser.line = port->serial->minor; 302 ser.port = port->number; 303 ser.baud_base = 460800; 304 305 if (copy_to_user((void __user *)arg, &ser, sizeof ser)) 306 return -EFAULT; 307 308 return 0; 309 310 case TIOCMIWAIT: 311 dev_dbg(&port->dev, "%s (%d) TIOCMIWAIT\n", __func__, 312 port->number); 313 return wait_modem_info(port, arg); 314 default: 315 dev_dbg(&port->dev, "%s not supported = 0x%04x\n", 316 __func__, cmd); 317 break; 318 } 319 return -ENOIOCTLCMD; 320 } 321 322 static int f81232_startup(struct usb_serial *serial) 323 { 324 struct f81232_private *priv; 325 int i; 326 327 for (i = 0; i < serial->num_ports; ++i) { 328 priv = kzalloc(sizeof(struct f81232_private), GFP_KERNEL); 329 if (!priv) 330 goto cleanup; 331 spin_lock_init(&priv->lock); 332 init_waitqueue_head(&priv->delta_msr_wait); 333 usb_set_serial_port_data(serial->port[i], priv); 334 } 335 return 0; 336 337 cleanup: 338 for (--i; i >= 0; --i) { 339 priv = usb_get_serial_port_data(serial->port[i]); 340 kfree(priv); 341 usb_set_serial_port_data(serial->port[i], NULL); 342 } 343 return -ENOMEM; 344 } 345 346 static void f81232_release(struct usb_serial *serial) 347 { 348 int i; 349 struct f81232_private *priv; 350 351 for (i = 0; i < serial->num_ports; ++i) { 352 priv = usb_get_serial_port_data(serial->port[i]); 353 kfree(priv); 354 } 355 } 356 357 static struct usb_serial_driver f81232_device = { 358 .driver = { 359 .owner = THIS_MODULE, 360 .name = "f81232", 361 }, 362 .id_table = id_table, 363 .num_ports = 1, 364 .bulk_in_size = 256, 365 .bulk_out_size = 256, 366 .open = f81232_open, 367 .close = f81232_close, 368 .dtr_rts = f81232_dtr_rts, 369 .carrier_raised = f81232_carrier_raised, 370 .ioctl = f81232_ioctl, 371 .break_ctl = f81232_break_ctl, 372 .set_termios = f81232_set_termios, 373 .tiocmget = f81232_tiocmget, 374 .tiocmset = f81232_tiocmset, 375 .process_read_urb = f81232_process_read_urb, 376 .read_int_callback = f81232_read_int_callback, 377 .attach = f81232_startup, 378 .release = f81232_release, 379 }; 380 381 static struct usb_serial_driver * const serial_drivers[] = { 382 &f81232_device, 383 NULL, 384 }; 385 386 module_usb_serial_driver(serial_drivers, id_table); 387 388 MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver"); 389 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org"); 390 MODULE_LICENSE("GPL v2"); 391 392 module_param(debug, bool, S_IRUGO | S_IWUSR); 393 MODULE_PARM_DESC(debug, "Debug enabled or not"); 394 395