drivers/tty/serial/ifx6x60.c

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This source file includes following definitions.
ifx_modem_power_off
ifx_modem_reboot_callback
mrdy_set_high
mrdy_set_low
ifx_spi_power_state_set
ifx_spi_power_state_clear
swap_buf_8
swap_buf_16
swap_buf_32
mrdy_assert
ifx_spi_timeout
ifx_spi_tiocmget
ifx_spi_tiocmset
ifx_spi_open
ifx_spi_close
ifx_spi_decode_spi_header
ifx_spi_setup_spi_header
ifx_spi_prepare_tx_buffer
ifx_spi_write
ifx_spi_write_room
ifx_spi_chars_in_buffer
ifx_spi_hangup
ifx_port_activate
ifx_port_shutdown
ifx_spi_insert_flip_string
ifx_spi_complete
ifx_spi_io
ifx_spi_free_port
ifx_spi_create_port
ifx_spi_handle_srdy
ifx_spi_srdy_interrupt
ifx_spi_reset_interrupt
ifx_spi_free_device
ifx_spi_reset
ifx_spi_spi_probe
ifx_spi_spi_remove
ifx_spi_spi_shutdown
ifx_spi_pm_suspend
ifx_spi_pm_resume
ifx_spi_pm_runtime_resume
ifx_spi_pm_runtime_suspend
ifx_spi_pm_runtime_idle
ifx_spi_exit
ifx_spi_init
   1 // SPDX-License-Identifier: GPL-2.0
   2 /****************************************************************************
   3  *
   4  * Driver for the IFX 6x60 spi modem.
   5  *
   6  * Copyright (C) 2008 Option International
   7  * Copyright (C) 2008 Filip Aben <f.aben@option.com>
   8  *                    Denis Joseph Barrow <d.barow@option.com>
   9  *                    Jan Dumon <j.dumon@option.com>
  10  *
  11  * Copyright (C) 2009, 2010 Intel Corp
  12  * Russ Gorby <russ.gorby@intel.com>
  13  *
  14  * Driver modified by Intel from Option gtm501l_spi.c
  15  *
  16  * Notes
  17  * o    The driver currently assumes a single device only. If you need to
  18  *      change this then look for saved_ifx_dev and add a device lookup
  19  * o    The driver is intended to be big-endian safe but has never been
  20  *      tested that way (no suitable hardware). There are a couple of FIXME
  21  *      notes by areas that may need addressing
  22  * o    Some of the GPIO naming/setup assumptions may need revisiting if
  23  *      you need to use this driver for another platform.
  24  *
  25  *****************************************************************************/
  26 #include <linux/dma-mapping.h>
  27 #include <linux/module.h>
  28 #include <linux/termios.h>
  29 #include <linux/tty.h>
  30 #include <linux/device.h>
  31 #include <linux/spi/spi.h>
  32 #include <linux/kfifo.h>
  33 #include <linux/tty_flip.h>
  34 #include <linux/timer.h>
  35 #include <linux/serial.h>
  36 #include <linux/interrupt.h>
  37 #include <linux/irq.h>
  38 #include <linux/rfkill.h>
  39 #include <linux/fs.h>
  40 #include <linux/ip.h>
  41 #include <linux/dmapool.h>
  42 #include <linux/gpio.h>
  43 #include <linux/sched.h>
  44 #include <linux/time.h>
  45 #include <linux/wait.h>
  46 #include <linux/pm.h>
  47 #include <linux/pm_runtime.h>
  48 #include <linux/spi/ifx_modem.h>
  49 #include <linux/delay.h>
  50 #include <linux/reboot.h>
  51 
  52 #include "ifx6x60.h"
  53 
  54 #define IFX_SPI_MORE_MASK               0x10
  55 #define IFX_SPI_MORE_BIT                4       /* bit position in u8 */
  56 #define IFX_SPI_CTS_BIT                 6       /* bit position in u8 */
  57 #define IFX_SPI_MODE                    SPI_MODE_1
  58 #define IFX_SPI_TTY_ID                  0
  59 #define IFX_SPI_TIMEOUT_SEC             2
  60 #define IFX_SPI_HEADER_0                (-1)
  61 #define IFX_SPI_HEADER_F                (-2)
  62 
  63 #define PO_POST_DELAY           200
  64 #define IFX_MDM_RST_PMU 4
  65 
  66 /* forward reference */
  67 static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev);
  68 static int ifx_modem_reboot_callback(struct notifier_block *nfb,
  69                                 unsigned long event, void *data);
  70 static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev);
  71 
  72 /* local variables */
  73 static int spi_bpw = 16;                /* 8, 16 or 32 bit word length */
  74 static struct tty_driver *tty_drv;
  75 static struct ifx_spi_device *saved_ifx_dev;
  76 static struct lock_class_key ifx_spi_key;
  77 
  78 static struct notifier_block ifx_modem_reboot_notifier_block = {
  79         .notifier_call = ifx_modem_reboot_callback,
  80 };
  81 
  82 static int ifx_modem_power_off(struct ifx_spi_device *ifx_dev)
  83 {
  84         gpio_set_value(IFX_MDM_RST_PMU, 1);
  85         msleep(PO_POST_DELAY);
  86 
  87         return 0;
  88 }
  89 
  90 static int ifx_modem_reboot_callback(struct notifier_block *nfb,
  91                                  unsigned long event, void *data)
  92 {
  93         if (saved_ifx_dev)
  94                 ifx_modem_power_off(saved_ifx_dev);
  95         else
  96                 pr_warn("no ifx modem active;\n");
  97 
  98         return NOTIFY_OK;
  99 }
 100 
 101 /* GPIO/GPE settings */
 102 
 103 /**
 104  *      mrdy_set_high           -       set MRDY GPIO
 105  *      @ifx: device we are controlling
 106  *
 107  */
 108 static inline void mrdy_set_high(struct ifx_spi_device *ifx)
 109 {
 110         gpio_set_value(ifx->gpio.mrdy, 1);
 111 }
 112 
 113 /**
 114  *      mrdy_set_low            -       clear MRDY GPIO
 115  *      @ifx: device we are controlling
 116  *
 117  */
 118 static inline void mrdy_set_low(struct ifx_spi_device *ifx)
 119 {
 120         gpio_set_value(ifx->gpio.mrdy, 0);
 121 }
 122 
 123 /**
 124  *      ifx_spi_power_state_set
 125  *      @ifx_dev: our SPI device
 126  *      @val: bits to set
 127  *
 128  *      Set bit in power status and signal power system if status becomes non-0
 129  */
 130 static void
 131 ifx_spi_power_state_set(struct ifx_spi_device *ifx_dev, unsigned char val)
 132 {
 133         unsigned long flags;
 134 
 135         spin_lock_irqsave(&ifx_dev->power_lock, flags);
 136 
 137         /*
 138          * if power status is already non-0, just update, else
 139          * tell power system
 140          */
 141         if (!ifx_dev->power_status)
 142                 pm_runtime_get(&ifx_dev->spi_dev->dev);
 143         ifx_dev->power_status |= val;
 144 
 145         spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
 146 }
 147 
 148 /**
 149  *      ifx_spi_power_state_clear       -       clear power bit
 150  *      @ifx_dev: our SPI device
 151  *      @val: bits to clear
 152  *
 153  *      clear bit in power status and signal power system if status becomes 0
 154  */
 155 static void
 156 ifx_spi_power_state_clear(struct ifx_spi_device *ifx_dev, unsigned char val)
 157 {
 158         unsigned long flags;
 159 
 160         spin_lock_irqsave(&ifx_dev->power_lock, flags);
 161 
 162         if (ifx_dev->power_status) {
 163                 ifx_dev->power_status &= ~val;
 164                 if (!ifx_dev->power_status)
 165                         pm_runtime_put(&ifx_dev->spi_dev->dev);
 166         }
 167 
 168         spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
 169 }
 170 
 171 /**
 172  *      swap_buf_8
 173  *      @buf: our buffer
 174  *      @len : number of bytes (not words) in the buffer
 175  *      @end: end of buffer
 176  *
 177  *      Swap the contents of a buffer into big endian format
 178  */
 179 static inline void swap_buf_8(unsigned char *buf, int len, void *end)
 180 {
 181         /* don't swap buffer if SPI word width is 8 bits */
 182         return;
 183 }
 184 
 185 /**
 186  *      swap_buf_16
 187  *      @buf: our buffer
 188  *      @len : number of bytes (not words) in the buffer
 189  *      @end: end of buffer
 190  *
 191  *      Swap the contents of a buffer into big endian format
 192  */
 193 static inline void swap_buf_16(unsigned char *buf, int len, void *end)
 194 {
 195         int n;
 196 
 197         u16 *buf_16 = (u16 *)buf;
 198         len = ((len + 1) >> 1);
 199         if ((void *)&buf_16[len] > end) {
 200                 pr_err("swap_buf_16: swap exceeds boundary (%p > %p)!",
 201                        &buf_16[len], end);
 202                 return;
 203         }
 204         for (n = 0; n < len; n++) {
 205                 *buf_16 = cpu_to_be16(*buf_16);
 206                 buf_16++;
 207         }
 208 }
 209 
 210 /**
 211  *      swap_buf_32
 212  *      @buf: our buffer
 213  *      @len : number of bytes (not words) in the buffer
 214  *      @end: end of buffer
 215  *
 216  *      Swap the contents of a buffer into big endian format
 217  */
 218 static inline void swap_buf_32(unsigned char *buf, int len, void *end)
 219 {
 220         int n;
 221 
 222         u32 *buf_32 = (u32 *)buf;
 223         len = (len + 3) >> 2;
 224 
 225         if ((void *)&buf_32[len] > end) {
 226                 pr_err("swap_buf_32: swap exceeds boundary (%p > %p)!\n",
 227                        &buf_32[len], end);
 228                 return;
 229         }
 230         for (n = 0; n < len; n++) {
 231                 *buf_32 = cpu_to_be32(*buf_32);
 232                 buf_32++;
 233         }
 234 }
 235 
 236 /**
 237  *      mrdy_assert             -       assert MRDY line
 238  *      @ifx_dev: our SPI device
 239  *
 240  *      Assert mrdy and set timer to wait for SRDY interrupt, if SRDY is low
 241  *      now.
 242  *
 243  *      FIXME: Can SRDY even go high as we are running this code ?
 244  */
 245 static void mrdy_assert(struct ifx_spi_device *ifx_dev)
 246 {
 247         int val = gpio_get_value(ifx_dev->gpio.srdy);
 248         if (!val) {
 249                 if (!test_and_set_bit(IFX_SPI_STATE_TIMER_PENDING,
 250                                       &ifx_dev->flags)) {
 251                         mod_timer(&ifx_dev->spi_timer,jiffies + IFX_SPI_TIMEOUT_SEC*HZ);
 252 
 253                 }
 254         }
 255         ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_DATA_PENDING);
 256         mrdy_set_high(ifx_dev);
 257 }
 258 
 259 /**
 260  *      ifx_spi_timeout         -       SPI timeout
 261  *      @arg: our SPI device
 262  *
 263  *      The SPI has timed out: hang up the tty. Users will then see a hangup
 264  *      and error events.
 265  */
 266 static void ifx_spi_timeout(struct timer_list *t)
 267 {
 268         struct ifx_spi_device *ifx_dev = from_timer(ifx_dev, t, spi_timer);
 269 
 270         dev_warn(&ifx_dev->spi_dev->dev, "*** SPI Timeout ***");
 271         tty_port_tty_hangup(&ifx_dev->tty_port, false);
 272         mrdy_set_low(ifx_dev);
 273         clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
 274 }
 275 
 276 /* char/tty operations */
 277 
 278 /**
 279  *      ifx_spi_tiocmget        -       get modem lines
 280  *      @tty: our tty device
 281  *      @filp: file handle issuing the request
 282  *
 283  *      Map the signal state into Linux modem flags and report the value
 284  *      in Linux terms
 285  */
 286 static int ifx_spi_tiocmget(struct tty_struct *tty)
 287 {
 288         unsigned int value;
 289         struct ifx_spi_device *ifx_dev = tty->driver_data;
 290 
 291         value =
 292         (test_bit(IFX_SPI_RTS, &ifx_dev->signal_state) ? TIOCM_RTS : 0) |
 293         (test_bit(IFX_SPI_DTR, &ifx_dev->signal_state) ? TIOCM_DTR : 0) |
 294         (test_bit(IFX_SPI_CTS, &ifx_dev->signal_state) ? TIOCM_CTS : 0) |
 295         (test_bit(IFX_SPI_DSR, &ifx_dev->signal_state) ? TIOCM_DSR : 0) |
 296         (test_bit(IFX_SPI_DCD, &ifx_dev->signal_state) ? TIOCM_CAR : 0) |
 297         (test_bit(IFX_SPI_RI, &ifx_dev->signal_state) ? TIOCM_RNG : 0);
 298         return value;
 299 }
 300 
 301 /**
 302  *      ifx_spi_tiocmset        -       set modem bits
 303  *      @tty: the tty structure
 304  *      @set: bits to set
 305  *      @clear: bits to clear
 306  *
 307  *      The IFX6x60 only supports DTR and RTS. Set them accordingly
 308  *      and flag that an update to the modem is needed.
 309  *
 310  *      FIXME: do we need to kick the tranfers when we do this ?
 311  */
 312 static int ifx_spi_tiocmset(struct tty_struct *tty,
 313                             unsigned int set, unsigned int clear)
 314 {
 315         struct ifx_spi_device *ifx_dev = tty->driver_data;
 316 
 317         if (set & TIOCM_RTS)
 318                 set_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
 319         if (set & TIOCM_DTR)
 320                 set_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
 321         if (clear & TIOCM_RTS)
 322                 clear_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
 323         if (clear & TIOCM_DTR)
 324                 clear_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
 325 
 326         set_bit(IFX_SPI_UPDATE, &ifx_dev->signal_state);
 327         return 0;
 328 }
 329 
 330 /**
 331  *      ifx_spi_open    -       called on tty open
 332  *      @tty: our tty device
 333  *      @filp: file handle being associated with the tty
 334  *
 335  *      Open the tty interface. We let the tty_port layer do all the work
 336  *      for us.
 337  *
 338  *      FIXME: Remove single device assumption and saved_ifx_dev
 339  */
 340 static int ifx_spi_open(struct tty_struct *tty, struct file *filp)
 341 {
 342         return tty_port_open(&saved_ifx_dev->tty_port, tty, filp);
 343 }
 344 
 345 /**
 346  *      ifx_spi_close   -       called when our tty closes
 347  *      @tty: the tty being closed
 348  *      @filp: the file handle being closed
 349  *
 350  *      Perform the close of the tty. We use the tty_port layer to do all
 351  *      our hard work.
 352  */
 353 static void ifx_spi_close(struct tty_struct *tty, struct file *filp)
 354 {
 355         struct ifx_spi_device *ifx_dev = tty->driver_data;
 356         tty_port_close(&ifx_dev->tty_port, tty, filp);
 357         /* FIXME: should we do an ifx_spi_reset here ? */
 358 }
 359 
 360 /**
 361  *      ifx_decode_spi_header   -       decode received header
 362  *      @buffer: the received data
 363  *      @length: decoded length
 364  *      @more: decoded more flag
 365  *      @received_cts: status of cts we received
 366  *
 367  *      Note how received_cts is handled -- if header is all F it is left
 368  *      the same as it was, if header is all 0 it is set to 0 otherwise it is
 369  *      taken from the incoming header.
 370  *
 371  *      FIXME: endianness
 372  */
 373 static int ifx_spi_decode_spi_header(unsigned char *buffer, int *length,
 374                         unsigned char *more, unsigned char *received_cts)
 375 {
 376         u16 h1;
 377         u16 h2;
 378         u16 *in_buffer = (u16 *)buffer;
 379 
 380         h1 = *in_buffer;
 381         h2 = *(in_buffer+1);
 382 
 383         if (h1 == 0 && h2 == 0) {
 384                 *received_cts = 0;
 385                 *more = 0;
 386                 return IFX_SPI_HEADER_0;
 387         } else if (h1 == 0xffff && h2 == 0xffff) {
 388                 *more = 0;
 389                 /* spi_slave_cts remains as it was */
 390                 return IFX_SPI_HEADER_F;
 391         }
 392 
 393         *length = h1 & 0xfff;   /* upper bits of byte are flags */
 394         *more = (buffer[1] >> IFX_SPI_MORE_BIT) & 1;
 395         *received_cts = (buffer[3] >> IFX_SPI_CTS_BIT) & 1;
 396         return 0;
 397 }
 398 
 399 /**
 400  *      ifx_setup_spi_header    -       set header fields
 401  *      @txbuffer: pointer to start of SPI buffer
 402  *      @tx_count: bytes
 403  *      @more: indicate if more to follow
 404  *
 405  *      Format up an SPI header for a transfer
 406  *
 407  *      FIXME: endianness?
 408  */
 409 static void ifx_spi_setup_spi_header(unsigned char *txbuffer, int tx_count,
 410                                         unsigned char more)
 411 {
 412         *(u16 *)(txbuffer) = tx_count;
 413         *(u16 *)(txbuffer+2) = IFX_SPI_PAYLOAD_SIZE;
 414         txbuffer[1] |= (more << IFX_SPI_MORE_BIT) & IFX_SPI_MORE_MASK;
 415 }
 416 
 417 /**
 418  *      ifx_spi_prepare_tx_buffer       -       prepare transmit frame
 419  *      @ifx_dev: our SPI device
 420  *
 421  *      The transmit buffr needs a header and various other bits of
 422  *      information followed by as much data as we can pull from the FIFO
 423  *      and transfer. This function formats up a suitable buffer in the
 424  *      ifx_dev->tx_buffer
 425  *
 426  *      FIXME: performance - should we wake the tty when the queue is half
 427  *                           empty ?
 428  */
 429 static int ifx_spi_prepare_tx_buffer(struct ifx_spi_device *ifx_dev)
 430 {
 431         int temp_count;
 432         int queue_length;
 433         int tx_count;
 434         unsigned char *tx_buffer;
 435 
 436         tx_buffer = ifx_dev->tx_buffer;
 437 
 438         /* make room for required SPI header */
 439         tx_buffer += IFX_SPI_HEADER_OVERHEAD;
 440         tx_count = IFX_SPI_HEADER_OVERHEAD;
 441 
 442         /* clear to signal no more data if this turns out to be the
 443          * last buffer sent in a sequence */
 444         ifx_dev->spi_more = 0;
 445 
 446         /* if modem cts is set, just send empty buffer */
 447         if (!ifx_dev->spi_slave_cts) {
 448                 /* see if there's tx data */
 449                 queue_length = kfifo_len(&ifx_dev->tx_fifo);
 450                 if (queue_length != 0) {
 451                         /* data to mux -- see if there's room for it */
 452                         temp_count = min(queue_length, IFX_SPI_PAYLOAD_SIZE);
 453                         temp_count = kfifo_out_locked(&ifx_dev->tx_fifo,
 454                                         tx_buffer, temp_count,
 455                                         &ifx_dev->fifo_lock);
 456 
 457                         /* update buffer pointer and data count in message */
 458                         tx_buffer += temp_count;
 459                         tx_count += temp_count;
 460                         if (temp_count == queue_length)
 461                                 /* poke port to get more data */
 462                                 tty_port_tty_wakeup(&ifx_dev->tty_port);
 463                         else /* more data in port, use next SPI message */
 464                                 ifx_dev->spi_more = 1;
 465                 }
 466         }
 467         /* have data and info for header -- set up SPI header in buffer */
 468         /* spi header needs payload size, not entire buffer size */
 469         ifx_spi_setup_spi_header(ifx_dev->tx_buffer,
 470                                         tx_count-IFX_SPI_HEADER_OVERHEAD,
 471                                         ifx_dev->spi_more);
 472         /* swap actual data in the buffer */
 473         ifx_dev->swap_buf((ifx_dev->tx_buffer), tx_count,
 474                 &ifx_dev->tx_buffer[IFX_SPI_TRANSFER_SIZE]);
 475         return tx_count;
 476 }
 477 
 478 /**
 479  *      ifx_spi_write           -       line discipline write
 480  *      @tty: our tty device
 481  *      @buf: pointer to buffer to write (kernel space)
 482  *      @count: size of buffer
 483  *
 484  *      Write the characters we have been given into the FIFO. If the device
 485  *      is not active then activate it, when the SRDY line is asserted back
 486  *      this will commence I/O
 487  */
 488 static int ifx_spi_write(struct tty_struct *tty, const unsigned char *buf,
 489                          int count)
 490 {
 491         struct ifx_spi_device *ifx_dev = tty->driver_data;
 492         unsigned char *tmp_buf = (unsigned char *)buf;
 493         unsigned long flags;
 494         bool is_fifo_empty;
 495         int tx_count;
 496 
 497         spin_lock_irqsave(&ifx_dev->fifo_lock, flags);
 498         is_fifo_empty = kfifo_is_empty(&ifx_dev->tx_fifo);
 499         tx_count = kfifo_in(&ifx_dev->tx_fifo, tmp_buf, count);
 500         spin_unlock_irqrestore(&ifx_dev->fifo_lock, flags);
 501         if (is_fifo_empty)
 502                 mrdy_assert(ifx_dev);
 503 
 504         return tx_count;
 505 }
 506 
 507 /**
 508  *      ifx_spi_chars_in_buffer -       line discipline helper
 509  *      @tty: our tty device
 510  *
 511  *      Report how much data we can accept before we drop bytes. As we use
 512  *      a simple FIFO this is nice and easy.
 513  */
 514 static int ifx_spi_write_room(struct tty_struct *tty)
 515 {
 516         struct ifx_spi_device *ifx_dev = tty->driver_data;
 517         return IFX_SPI_FIFO_SIZE - kfifo_len(&ifx_dev->tx_fifo);
 518 }
 519 
 520 /**
 521  *      ifx_spi_chars_in_buffer -       line discipline helper
 522  *      @tty: our tty device
 523  *
 524  *      Report how many characters we have buffered. In our case this is the
 525  *      number of bytes sitting in our transmit FIFO.
 526  */
 527 static int ifx_spi_chars_in_buffer(struct tty_struct *tty)
 528 {
 529         struct ifx_spi_device *ifx_dev = tty->driver_data;
 530         return kfifo_len(&ifx_dev->tx_fifo);
 531 }
 532 
 533 /**
 534  *      ifx_port_hangup
 535  *      @port: our tty port
 536  *
 537  *      tty port hang up. Called when tty_hangup processing is invoked either
 538  *      by loss of carrier, or by software (eg vhangup). Serialized against
 539  *      activate/shutdown by the tty layer.
 540  */
 541 static void ifx_spi_hangup(struct tty_struct *tty)
 542 {
 543         struct ifx_spi_device *ifx_dev = tty->driver_data;
 544         tty_port_hangup(&ifx_dev->tty_port);
 545 }
 546 
 547 /**
 548  *      ifx_port_activate
 549  *      @port: our tty port
 550  *
 551  *      tty port activate method - called for first open. Serialized
 552  *      with hangup and shutdown by the tty layer.
 553  */
 554 static int ifx_port_activate(struct tty_port *port, struct tty_struct *tty)
 555 {
 556         struct ifx_spi_device *ifx_dev =
 557                 container_of(port, struct ifx_spi_device, tty_port);
 558 
 559         /* clear any old data; can't do this in 'close' */
 560         kfifo_reset(&ifx_dev->tx_fifo);
 561 
 562         /* clear any flag which may be set in port shutdown procedure */
 563         clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
 564         clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);
 565 
 566         /* put port data into this tty */
 567         tty->driver_data = ifx_dev;
 568 
 569         /* allows flip string push from int context */
 570         port->low_latency = 1;
 571 
 572         /* set flag to allows data transfer */
 573         set_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags);
 574 
 575         return 0;
 576 }
 577 
 578 /**
 579  *      ifx_port_shutdown
 580  *      @port: our tty port
 581  *
 582  *      tty port shutdown method - called for last port close. Serialized
 583  *      with hangup and activate by the tty layer.
 584  */
 585 static void ifx_port_shutdown(struct tty_port *port)
 586 {
 587         struct ifx_spi_device *ifx_dev =
 588                 container_of(port, struct ifx_spi_device, tty_port);
 589 
 590         clear_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags);
 591         mrdy_set_low(ifx_dev);
 592         del_timer(&ifx_dev->spi_timer);
 593         clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
 594         tasklet_kill(&ifx_dev->io_work_tasklet);
 595 }
 596 
 597 static const struct tty_port_operations ifx_tty_port_ops = {
 598         .activate = ifx_port_activate,
 599         .shutdown = ifx_port_shutdown,
 600 };
 601 
 602 static const struct tty_operations ifx_spi_serial_ops = {
 603         .open = ifx_spi_open,
 604         .close = ifx_spi_close,
 605         .write = ifx_spi_write,
 606         .hangup = ifx_spi_hangup,
 607         .write_room = ifx_spi_write_room,
 608         .chars_in_buffer = ifx_spi_chars_in_buffer,
 609         .tiocmget = ifx_spi_tiocmget,
 610         .tiocmset = ifx_spi_tiocmset,
 611 };
 612 
 613 /**
 614  *      ifx_spi_insert_fip_string       -       queue received data
 615  *      @ifx_ser: our SPI device
 616  *      @chars: buffer we have received
 617  *      @size: number of chars reeived
 618  *
 619  *      Queue bytes to the tty assuming the tty side is currently open. If
 620  *      not the discard the data.
 621  */
 622 static void ifx_spi_insert_flip_string(struct ifx_spi_device *ifx_dev,
 623                                     unsigned char *chars, size_t size)
 624 {
 625         tty_insert_flip_string(&ifx_dev->tty_port, chars, size);
 626         tty_flip_buffer_push(&ifx_dev->tty_port);
 627 }
 628 
 629 /**
 630  *      ifx_spi_complete        -       SPI transfer completed
 631  *      @ctx: our SPI device
 632  *
 633  *      An SPI transfer has completed. Process any received data and kick off
 634  *      any further transmits we can commence.
 635  */
 636 static void ifx_spi_complete(void *ctx)
 637 {
 638         struct ifx_spi_device *ifx_dev = ctx;
 639         int length;
 640         int actual_length;
 641         unsigned char more = 0;
 642         unsigned char cts;
 643         int local_write_pending = 0;
 644         int queue_length;
 645         int srdy;
 646         int decode_result;
 647 
 648         mrdy_set_low(ifx_dev);
 649 
 650         if (!ifx_dev->spi_msg.status) {
 651                 /* check header validity, get comm flags */
 652                 ifx_dev->swap_buf(ifx_dev->rx_buffer, IFX_SPI_HEADER_OVERHEAD,
 653                         &ifx_dev->rx_buffer[IFX_SPI_HEADER_OVERHEAD]);
 654                 decode_result = ifx_spi_decode_spi_header(ifx_dev->rx_buffer,
 655                                 &length, &more, &cts);
 656                 if (decode_result == IFX_SPI_HEADER_0) {
 657                         dev_dbg(&ifx_dev->spi_dev->dev,
 658                                 "ignore input: invalid header 0");
 659                         ifx_dev->spi_slave_cts = 0;
 660                         goto complete_exit;
 661                 } else if (decode_result == IFX_SPI_HEADER_F) {
 662                         dev_dbg(&ifx_dev->spi_dev->dev,
 663                                 "ignore input: invalid header F");
 664                         goto complete_exit;
 665                 }
 666 
 667                 ifx_dev->spi_slave_cts = cts;
 668 
 669                 actual_length = min((unsigned int)length,
 670                                         ifx_dev->spi_msg.actual_length);
 671                 ifx_dev->swap_buf(
 672                         (ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD),
 673                          actual_length,
 674                          &ifx_dev->rx_buffer[IFX_SPI_TRANSFER_SIZE]);
 675                 ifx_spi_insert_flip_string(
 676                         ifx_dev,
 677                         ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD,
 678                         (size_t)actual_length);
 679         } else {
 680                 more = 0;
 681                 dev_dbg(&ifx_dev->spi_dev->dev, "SPI transfer error %d",
 682                        ifx_dev->spi_msg.status);
 683         }
 684 
 685 complete_exit:
 686         if (ifx_dev->write_pending) {
 687                 ifx_dev->write_pending = 0;
 688                 local_write_pending = 1;
 689         }
 690 
 691         clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &(ifx_dev->flags));
 692 
 693         queue_length = kfifo_len(&ifx_dev->tx_fifo);
 694         srdy = gpio_get_value(ifx_dev->gpio.srdy);
 695         if (!srdy)
 696                 ifx_spi_power_state_clear(ifx_dev, IFX_SPI_POWER_SRDY);
 697 
 698         /* schedule output if there is more to do */
 699         if (test_and_clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags))
 700                 tasklet_schedule(&ifx_dev->io_work_tasklet);
 701         else {
 702                 if (more || ifx_dev->spi_more || queue_length > 0 ||
 703                         local_write_pending) {
 704                         if (ifx_dev->spi_slave_cts) {
 705                                 if (more)
 706                                         mrdy_assert(ifx_dev);
 707                         } else
 708                                 mrdy_assert(ifx_dev);
 709                 } else {
 710                         /*
 711                          * poke line discipline driver if any for more data
 712                          * may or may not get more data to write
 713                          * for now, say not busy
 714                          */
 715                         ifx_spi_power_state_clear(ifx_dev,
 716                                                   IFX_SPI_POWER_DATA_PENDING);
 717                         tty_port_tty_wakeup(&ifx_dev->tty_port);
 718                 }
 719         }
 720 }
 721 
 722 /**
 723  *      ifx_spio_io             -       I/O tasklet
 724  *      @data: our SPI device
 725  *
 726  *      Queue data for transmission if possible and then kick off the
 727  *      transfer.
 728  */
 729 static void ifx_spi_io(unsigned long data)
 730 {
 731         int retval;
 732         struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *) data;
 733 
 734         if (!test_and_set_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags) &&
 735                 test_bit(IFX_SPI_STATE_IO_AVAILABLE, &ifx_dev->flags)) {
 736                 if (ifx_dev->gpio.unack_srdy_int_nb > 0)
 737                         ifx_dev->gpio.unack_srdy_int_nb--;
 738 
 739                 ifx_spi_prepare_tx_buffer(ifx_dev);
 740 
 741                 spi_message_init(&ifx_dev->spi_msg);
 742                 INIT_LIST_HEAD(&ifx_dev->spi_msg.queue);
 743 
 744                 ifx_dev->spi_msg.context = ifx_dev;
 745                 ifx_dev->spi_msg.complete = ifx_spi_complete;
 746 
 747                 /* set up our spi transfer */
 748                 /* note len is BYTES, not transfers */
 749                 ifx_dev->spi_xfer.len = IFX_SPI_TRANSFER_SIZE;
 750                 ifx_dev->spi_xfer.cs_change = 0;
 751                 ifx_dev->spi_xfer.speed_hz = ifx_dev->spi_dev->max_speed_hz;
 752                 /* ifx_dev->spi_xfer.speed_hz = 390625; */
 753                 ifx_dev->spi_xfer.bits_per_word =
 754                         ifx_dev->spi_dev->bits_per_word;
 755 
 756                 ifx_dev->spi_xfer.tx_buf = ifx_dev->tx_buffer;
 757                 ifx_dev->spi_xfer.rx_buf = ifx_dev->rx_buffer;
 758 
 759                 /*
 760                  * setup dma pointers
 761                  */
 762                 if (ifx_dev->use_dma) {
 763                         ifx_dev->spi_msg.is_dma_mapped = 1;
 764                         ifx_dev->tx_dma = ifx_dev->tx_bus;
 765                         ifx_dev->rx_dma = ifx_dev->rx_bus;
 766                         ifx_dev->spi_xfer.tx_dma = ifx_dev->tx_dma;
 767                         ifx_dev->spi_xfer.rx_dma = ifx_dev->rx_dma;
 768                 } else {
 769                         ifx_dev->spi_msg.is_dma_mapped = 0;
 770                         ifx_dev->tx_dma = (dma_addr_t)0;
 771                         ifx_dev->rx_dma = (dma_addr_t)0;
 772                         ifx_dev->spi_xfer.tx_dma = (dma_addr_t)0;
 773                         ifx_dev->spi_xfer.rx_dma = (dma_addr_t)0;
 774                 }
 775 
 776                 spi_message_add_tail(&ifx_dev->spi_xfer, &ifx_dev->spi_msg);
 777 
 778                 /* Assert MRDY. This may have already been done by the write
 779                  * routine.
 780                  */
 781                 mrdy_assert(ifx_dev);
 782 
 783                 retval = spi_async(ifx_dev->spi_dev, &ifx_dev->spi_msg);
 784                 if (retval) {
 785                         clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS,
 786                                   &ifx_dev->flags);
 787                         tasklet_schedule(&ifx_dev->io_work_tasklet);
 788                         return;
 789                 }
 790         } else
 791                 ifx_dev->write_pending = 1;
 792 }
 793 
 794 /**
 795  *      ifx_spi_free_port       -       free up the tty side
 796  *      @ifx_dev: IFX device going away
 797  *
 798  *      Unregister and free up a port when the device goes away
 799  */
 800 static void ifx_spi_free_port(struct ifx_spi_device *ifx_dev)
 801 {
 802         if (ifx_dev->tty_dev)
 803                 tty_unregister_device(tty_drv, ifx_dev->minor);
 804         tty_port_destroy(&ifx_dev->tty_port);
 805         kfifo_free(&ifx_dev->tx_fifo);
 806 }
 807 
 808 /**
 809  *      ifx_spi_create_port     -       create a new port
 810  *      @ifx_dev: our spi device
 811  *
 812  *      Allocate and initialise the tty port that goes with this interface
 813  *      and add it to the tty layer so that it can be opened.
 814  */
 815 static int ifx_spi_create_port(struct ifx_spi_device *ifx_dev)
 816 {
 817         int ret = 0;
 818         struct tty_port *pport = &ifx_dev->tty_port;
 819 
 820         spin_lock_init(&ifx_dev->fifo_lock);
 821         lockdep_set_class_and_subclass(&ifx_dev->fifo_lock,
 822                 &ifx_spi_key, 0);
 823 
 824         if (kfifo_alloc(&ifx_dev->tx_fifo, IFX_SPI_FIFO_SIZE, GFP_KERNEL)) {
 825                 ret = -ENOMEM;
 826                 goto error_ret;
 827         }
 828 
 829         tty_port_init(pport);
 830         pport->ops = &ifx_tty_port_ops;
 831         ifx_dev->minor = IFX_SPI_TTY_ID;
 832         ifx_dev->tty_dev = tty_port_register_device(pport, tty_drv,
 833                         ifx_dev->minor, &ifx_dev->spi_dev->dev);
 834         if (IS_ERR(ifx_dev->tty_dev)) {
 835                 dev_dbg(&ifx_dev->spi_dev->dev,
 836                         "%s: registering tty device failed", __func__);
 837                 ret = PTR_ERR(ifx_dev->tty_dev);
 838                 goto error_port;
 839         }
 840         return 0;
 841 
 842 error_port:
 843         tty_port_destroy(pport);
 844 error_ret:
 845         ifx_spi_free_port(ifx_dev);
 846         return ret;
 847 }
 848 
 849 /**
 850  *      ifx_spi_handle_srdy             -       handle SRDY
 851  *      @ifx_dev: device asserting SRDY
 852  *
 853  *      Check our device state and see what we need to kick off when SRDY
 854  *      is asserted. This usually means killing the timer and firing off the
 855  *      I/O processing.
 856  */
 857 static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev)
 858 {
 859         if (test_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags)) {
 860                 del_timer(&ifx_dev->spi_timer);
 861                 clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
 862         }
 863 
 864         ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_SRDY);
 865 
 866         if (!test_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags))
 867                 tasklet_schedule(&ifx_dev->io_work_tasklet);
 868         else
 869                 set_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);
 870 }
 871 
 872 /**
 873  *      ifx_spi_srdy_interrupt  -       SRDY asserted
 874  *      @irq: our IRQ number
 875  *      @dev: our ifx device
 876  *
 877  *      The modem asserted SRDY. Handle the srdy event
 878  */
 879 static irqreturn_t ifx_spi_srdy_interrupt(int irq, void *dev)
 880 {
 881         struct ifx_spi_device *ifx_dev = dev;
 882         ifx_dev->gpio.unack_srdy_int_nb++;
 883         ifx_spi_handle_srdy(ifx_dev);
 884         return IRQ_HANDLED;
 885 }
 886 
 887 /**
 888  *      ifx_spi_reset_interrupt -       Modem has changed reset state
 889  *      @irq: interrupt number
 890  *      @dev: our device pointer
 891  *
 892  *      The modem has either entered or left reset state. Check the GPIO
 893  *      line to see which.
 894  *
 895  *      FIXME: review locking on MR_INPROGRESS versus
 896  *      parallel unsolicited reset/solicited reset
 897  */
 898 static irqreturn_t ifx_spi_reset_interrupt(int irq, void *dev)
 899 {
 900         struct ifx_spi_device *ifx_dev = dev;
 901         int val = gpio_get_value(ifx_dev->gpio.reset_out);
 902         int solreset = test_bit(MR_START, &ifx_dev->mdm_reset_state);
 903 
 904         if (val == 0) {
 905                 /* entered reset */
 906                 set_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
 907                 if (!solreset) {
 908                         /* unsolicited reset  */
 909                         tty_port_tty_hangup(&ifx_dev->tty_port, false);
 910                 }
 911         } else {
 912                 /* exited reset */
 913                 clear_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
 914                 if (solreset) {
 915                         set_bit(MR_COMPLETE, &ifx_dev->mdm_reset_state);
 916                         wake_up(&ifx_dev->mdm_reset_wait);
 917                 }
 918         }
 919         return IRQ_HANDLED;
 920 }
 921 
 922 /**
 923  *      ifx_spi_free_device - free device
 924  *      @ifx_dev: device to free
 925  *
 926  *      Free the IFX device
 927  */
 928 static void ifx_spi_free_device(struct ifx_spi_device *ifx_dev)
 929 {
 930         ifx_spi_free_port(ifx_dev);
 931         dma_free_coherent(&ifx_dev->spi_dev->dev,
 932                                 IFX_SPI_TRANSFER_SIZE,
 933                                 ifx_dev->tx_buffer,
 934                                 ifx_dev->tx_bus);
 935         dma_free_coherent(&ifx_dev->spi_dev->dev,
 936                                 IFX_SPI_TRANSFER_SIZE,
 937                                 ifx_dev->rx_buffer,
 938                                 ifx_dev->rx_bus);
 939 }
 940 
 941 /**
 942  *      ifx_spi_reset   -       reset modem
 943  *      @ifx_dev: modem to reset
 944  *
 945  *      Perform a reset on the modem
 946  */
 947 static int ifx_spi_reset(struct ifx_spi_device *ifx_dev)
 948 {
 949         int ret;
 950         /*
 951          * set up modem power, reset
 952          *
 953          * delays are required on some platforms for the modem
 954          * to reset properly
 955          */
 956         set_bit(MR_START, &ifx_dev->mdm_reset_state);
 957         gpio_set_value(ifx_dev->gpio.po, 0);
 958         gpio_set_value(ifx_dev->gpio.reset, 0);
 959         msleep(25);
 960         gpio_set_value(ifx_dev->gpio.reset, 1);
 961         msleep(1);
 962         gpio_set_value(ifx_dev->gpio.po, 1);
 963         msleep(1);
 964         gpio_set_value(ifx_dev->gpio.po, 0);
 965         ret = wait_event_timeout(ifx_dev->mdm_reset_wait,
 966                                  test_bit(MR_COMPLETE,
 967                                           &ifx_dev->mdm_reset_state),
 968                                  IFX_RESET_TIMEOUT);
 969         if (!ret)
 970                 dev_warn(&ifx_dev->spi_dev->dev, "Modem reset timeout: (state:%lx)",
 971                          ifx_dev->mdm_reset_state);
 972 
 973         ifx_dev->mdm_reset_state = 0;
 974         return ret;
 975 }
 976 
 977 /**
 978  *      ifx_spi_spi_probe       -       probe callback
 979  *      @spi: our possible matching SPI device
 980  *
 981  *      Probe for a 6x60 modem on SPI bus. Perform any needed device and
 982  *      GPIO setup.
 983  *
 984  *      FIXME:
 985  *      -       Support for multiple devices
 986  *      -       Split out MID specific GPIO handling eventually
 987  */
 988 
 989 static int ifx_spi_spi_probe(struct spi_device *spi)
 990 {
 991         int ret;
 992         int srdy;
 993         struct ifx_modem_platform_data *pl_data;
 994         struct ifx_spi_device *ifx_dev;
 995 
 996         if (saved_ifx_dev) {
 997                 dev_dbg(&spi->dev, "ignoring subsequent detection");
 998                 return -ENODEV;
 999         }
1000 
1001         pl_data = dev_get_platdata(&spi->dev);
1002         if (!pl_data) {
1003                 dev_err(&spi->dev, "missing platform data!");
1004                 return -ENODEV;
1005         }
1006 
1007         /* initialize structure to hold our device variables */
1008         ifx_dev = kzalloc(sizeof(struct ifx_spi_device), GFP_KERNEL);
1009         if (!ifx_dev) {
1010                 dev_err(&spi->dev, "spi device allocation failed");
1011                 return -ENOMEM;
1012         }
1013         saved_ifx_dev = ifx_dev;
1014         ifx_dev->spi_dev = spi;
1015         clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
1016         spin_lock_init(&ifx_dev->write_lock);
1017         spin_lock_init(&ifx_dev->power_lock);
1018         ifx_dev->power_status = 0;
1019         timer_setup(&ifx_dev->spi_timer, ifx_spi_timeout, 0);
1020         ifx_dev->modem = pl_data->modem_type;
1021         ifx_dev->use_dma = pl_data->use_dma;
1022         ifx_dev->max_hz = pl_data->max_hz;
1023         /* initialize spi mode, etc */
1024         spi->max_speed_hz = ifx_dev->max_hz;
1025         spi->mode = IFX_SPI_MODE | (SPI_LOOP & spi->mode);
1026         spi->bits_per_word = spi_bpw;
1027         ret = spi_setup(spi);
1028         if (ret) {
1029                 dev_err(&spi->dev, "SPI setup wasn't successful %d", ret);
1030                 kfree(ifx_dev);
1031                 return -ENODEV;
1032         }
1033 
1034         /* init swap_buf function according to word width configuration */
1035         if (spi->bits_per_word == 32)
1036                 ifx_dev->swap_buf = swap_buf_32;
1037         else if (spi->bits_per_word == 16)
1038                 ifx_dev->swap_buf = swap_buf_16;
1039         else
1040                 ifx_dev->swap_buf = swap_buf_8;
1041 
1042         /* ensure SPI protocol flags are initialized to enable transfer */
1043         ifx_dev->spi_more = 0;
1044         ifx_dev->spi_slave_cts = 0;
1045 
1046         /*initialize transfer and dma buffers */
1047         ifx_dev->tx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent,
1048                                 IFX_SPI_TRANSFER_SIZE,
1049                                 &ifx_dev->tx_bus,
1050                                 GFP_KERNEL);
1051         if (!ifx_dev->tx_buffer) {
1052                 dev_err(&spi->dev, "DMA-TX buffer allocation failed");
1053                 ret = -ENOMEM;
1054                 goto error_ret;
1055         }
1056         ifx_dev->rx_buffer = dma_alloc_coherent(ifx_dev->spi_dev->dev.parent,
1057                                 IFX_SPI_TRANSFER_SIZE,
1058                                 &ifx_dev->rx_bus,
1059                                 GFP_KERNEL);
1060         if (!ifx_dev->rx_buffer) {
1061                 dev_err(&spi->dev, "DMA-RX buffer allocation failed");
1062                 ret = -ENOMEM;
1063                 goto error_ret;
1064         }
1065 
1066         /* initialize waitq for modem reset */
1067         init_waitqueue_head(&ifx_dev->mdm_reset_wait);
1068 
1069         spi_set_drvdata(spi, ifx_dev);
1070         tasklet_init(&ifx_dev->io_work_tasklet, ifx_spi_io,
1071                                                 (unsigned long)ifx_dev);
1072 
1073         set_bit(IFX_SPI_STATE_PRESENT, &ifx_dev->flags);
1074 
1075         /* create our tty port */
1076         ret = ifx_spi_create_port(ifx_dev);
1077         if (ret != 0) {
1078                 dev_err(&spi->dev, "create default tty port failed");
1079                 goto error_ret;
1080         }
1081 
1082         ifx_dev->gpio.reset = pl_data->rst_pmu;
1083         ifx_dev->gpio.po = pl_data->pwr_on;
1084         ifx_dev->gpio.mrdy = pl_data->mrdy;
1085         ifx_dev->gpio.srdy = pl_data->srdy;
1086         ifx_dev->gpio.reset_out = pl_data->rst_out;
1087 
1088         dev_info(&spi->dev, "gpios %d, %d, %d, %d, %d",
1089                  ifx_dev->gpio.reset, ifx_dev->gpio.po, ifx_dev->gpio.mrdy,
1090                  ifx_dev->gpio.srdy, ifx_dev->gpio.reset_out);
1091 
1092         /* Configure gpios */
1093         ret = gpio_request(ifx_dev->gpio.reset, "ifxModem");
1094         if (ret < 0) {
1095                 dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET)",
1096                         ifx_dev->gpio.reset);
1097                 goto error_ret;
1098         }
1099         ret += gpio_direction_output(ifx_dev->gpio.reset, 0);
1100         ret += gpio_export(ifx_dev->gpio.reset, 1);
1101         if (ret) {
1102                 dev_err(&spi->dev, "Unable to configure GPIO%d (RESET)",
1103                         ifx_dev->gpio.reset);
1104                 ret = -EBUSY;
1105                 goto error_ret2;
1106         }
1107 
1108         ret = gpio_request(ifx_dev->gpio.po, "ifxModem");
1109         ret += gpio_direction_output(ifx_dev->gpio.po, 0);
1110         ret += gpio_export(ifx_dev->gpio.po, 1);
1111         if (ret) {
1112                 dev_err(&spi->dev, "Unable to configure GPIO%d (ON)",
1113                         ifx_dev->gpio.po);
1114                 ret = -EBUSY;
1115                 goto error_ret3;
1116         }
1117 
1118         ret = gpio_request(ifx_dev->gpio.mrdy, "ifxModem");
1119         if (ret < 0) {
1120                 dev_err(&spi->dev, "Unable to allocate GPIO%d (MRDY)",
1121                         ifx_dev->gpio.mrdy);
1122                 goto error_ret3;
1123         }
1124         ret += gpio_export(ifx_dev->gpio.mrdy, 1);
1125         ret += gpio_direction_output(ifx_dev->gpio.mrdy, 0);
1126         if (ret) {
1127                 dev_err(&spi->dev, "Unable to configure GPIO%d (MRDY)",
1128                         ifx_dev->gpio.mrdy);
1129                 ret = -EBUSY;
1130                 goto error_ret4;
1131         }
1132 
1133         ret = gpio_request(ifx_dev->gpio.srdy, "ifxModem");
1134         if (ret < 0) {
1135                 dev_err(&spi->dev, "Unable to allocate GPIO%d (SRDY)",
1136                         ifx_dev->gpio.srdy);
1137                 ret = -EBUSY;
1138                 goto error_ret4;
1139         }
1140         ret += gpio_export(ifx_dev->gpio.srdy, 1);
1141         ret += gpio_direction_input(ifx_dev->gpio.srdy);
1142         if (ret) {
1143                 dev_err(&spi->dev, "Unable to configure GPIO%d (SRDY)",
1144                         ifx_dev->gpio.srdy);
1145                 ret = -EBUSY;
1146                 goto error_ret5;
1147         }
1148 
1149         ret = gpio_request(ifx_dev->gpio.reset_out, "ifxModem");
1150         if (ret < 0) {
1151                 dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET_OUT)",
1152                         ifx_dev->gpio.reset_out);
1153                 goto error_ret5;
1154         }
1155         ret += gpio_export(ifx_dev->gpio.reset_out, 1);
1156         ret += gpio_direction_input(ifx_dev->gpio.reset_out);
1157         if (ret) {
1158                 dev_err(&spi->dev, "Unable to configure GPIO%d (RESET_OUT)",
1159                         ifx_dev->gpio.reset_out);
1160                 ret = -EBUSY;
1161                 goto error_ret6;
1162         }
1163 
1164         ret = request_irq(gpio_to_irq(ifx_dev->gpio.reset_out),
1165                           ifx_spi_reset_interrupt,
1166                           IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING, DRVNAME,
1167                           ifx_dev);
1168         if (ret) {
1169                 dev_err(&spi->dev, "Unable to get irq %x\n",
1170                         gpio_to_irq(ifx_dev->gpio.reset_out));
1171                 goto error_ret6;
1172         }
1173 
1174         ret = ifx_spi_reset(ifx_dev);
1175 
1176         ret = request_irq(gpio_to_irq(ifx_dev->gpio.srdy),
1177                           ifx_spi_srdy_interrupt, IRQF_TRIGGER_RISING, DRVNAME,
1178                           ifx_dev);
1179         if (ret) {
1180                 dev_err(&spi->dev, "Unable to get irq %x",
1181                         gpio_to_irq(ifx_dev->gpio.srdy));
1182                 goto error_ret7;
1183         }
1184 
1185         /* set pm runtime power state and register with power system */
1186         pm_runtime_set_active(&spi->dev);
1187         pm_runtime_enable(&spi->dev);
1188 
1189         /* handle case that modem is already signaling SRDY */
1190         /* no outgoing tty open at this point, this just satisfies the
1191          * modem's read and should reset communication properly
1192          */
1193         srdy = gpio_get_value(ifx_dev->gpio.srdy);
1194 
1195         if (srdy) {
1196                 mrdy_assert(ifx_dev);
1197                 ifx_spi_handle_srdy(ifx_dev);
1198         } else
1199                 mrdy_set_low(ifx_dev);
1200         return 0;
1201 
1202 error_ret7:
1203         free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
1204 error_ret6:
1205         gpio_free(ifx_dev->gpio.srdy);
1206 error_ret5:
1207         gpio_free(ifx_dev->gpio.mrdy);
1208 error_ret4:
1209         gpio_free(ifx_dev->gpio.reset);
1210 error_ret3:
1211         gpio_free(ifx_dev->gpio.po);
1212 error_ret2:
1213         gpio_free(ifx_dev->gpio.reset_out);
1214 error_ret:
1215         ifx_spi_free_device(ifx_dev);
1216         saved_ifx_dev = NULL;
1217         return ret;
1218 }
1219 
1220 /**
1221  *      ifx_spi_spi_remove      -       SPI device was removed
1222  *      @spi: SPI device
1223  *
1224  *      FIXME: We should be shutting the device down here not in
1225  *      the module unload path.
1226  */
1227 
1228 static int ifx_spi_spi_remove(struct spi_device *spi)
1229 {
1230         struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1231         /* stop activity */
1232         tasklet_kill(&ifx_dev->io_work_tasklet);
1233 
1234         pm_runtime_disable(&spi->dev);
1235 
1236         /* free irq */
1237         free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), ifx_dev);
1238         free_irq(gpio_to_irq(ifx_dev->gpio.srdy), ifx_dev);
1239 
1240         gpio_free(ifx_dev->gpio.srdy);
1241         gpio_free(ifx_dev->gpio.mrdy);
1242         gpio_free(ifx_dev->gpio.reset);
1243         gpio_free(ifx_dev->gpio.po);
1244         gpio_free(ifx_dev->gpio.reset_out);
1245 
1246         /* free allocations */
1247         ifx_spi_free_device(ifx_dev);
1248 
1249         saved_ifx_dev = NULL;
1250         return 0;
1251 }
1252 
1253 /**
1254  *      ifx_spi_spi_shutdown    -       called on SPI shutdown
1255  *      @spi: SPI device
1256  *
1257  *      No action needs to be taken here
1258  */
1259 
1260 static void ifx_spi_spi_shutdown(struct spi_device *spi)
1261 {
1262         struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1263 
1264         ifx_modem_power_off(ifx_dev);
1265 }
1266 
1267 /*
1268  * various suspends and resumes have nothing to do
1269  * no hardware to save state for
1270  */
1271 
1272 /**
1273  *      ifx_spi_pm_suspend      -       suspend modem on system suspend
1274  *      @dev: device being suspended
1275  *
1276  *      Suspend the modem. No action needed on Intel MID platforms, may
1277  *      need extending for other systems.
1278  */
1279 static int ifx_spi_pm_suspend(struct device *dev)
1280 {
1281         return 0;
1282 }
1283 
1284 /**
1285  *      ifx_spi_pm_resume       -       resume modem on system resume
1286  *      @dev: device being suspended
1287  *
1288  *      Allow the modem to resume. No action needed.
1289  *
1290  *      FIXME: do we need to reset anything here ?
1291  */
1292 static int ifx_spi_pm_resume(struct device *dev)
1293 {
1294         return 0;
1295 }
1296 
1297 /**
1298  *      ifx_spi_pm_runtime_resume       -       suspend modem
1299  *      @dev: device being suspended
1300  *
1301  *      Allow the modem to resume. No action needed.
1302  */
1303 static int ifx_spi_pm_runtime_resume(struct device *dev)
1304 {
1305         return 0;
1306 }
1307 
1308 /**
1309  *      ifx_spi_pm_runtime_suspend      -       suspend modem
1310  *      @dev: device being suspended
1311  *
1312  *      Allow the modem to suspend and thus suspend to continue up the
1313  *      device tree.
1314  */
1315 static int ifx_spi_pm_runtime_suspend(struct device *dev)
1316 {
1317         return 0;
1318 }
1319 
1320 /**
1321  *      ifx_spi_pm_runtime_idle         -       check if modem idle
1322  *      @dev: our device
1323  *
1324  *      Check conditions and queue runtime suspend if idle.
1325  */
1326 static int ifx_spi_pm_runtime_idle(struct device *dev)
1327 {
1328         struct spi_device *spi = to_spi_device(dev);
1329         struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
1330 
1331         if (!ifx_dev->power_status)
1332                 pm_runtime_suspend(dev);
1333 
1334         return 0;
1335 }
1336 
1337 static const struct dev_pm_ops ifx_spi_pm = {
1338         .resume = ifx_spi_pm_resume,
1339         .suspend = ifx_spi_pm_suspend,
1340         .runtime_resume = ifx_spi_pm_runtime_resume,
1341         .runtime_suspend = ifx_spi_pm_runtime_suspend,
1342         .runtime_idle = ifx_spi_pm_runtime_idle
1343 };
1344 
1345 static const struct spi_device_id ifx_id_table[] = {
1346         {"ifx6160", 0},
1347         {"ifx6260", 0},
1348         { }
1349 };
1350 MODULE_DEVICE_TABLE(spi, ifx_id_table);
1351 
1352 /* spi operations */
1353 static struct spi_driver ifx_spi_driver = {
1354         .driver = {
1355                 .name = DRVNAME,
1356                 .pm = &ifx_spi_pm,
1357         },
1358         .probe = ifx_spi_spi_probe,
1359         .shutdown = ifx_spi_spi_shutdown,
1360         .remove = ifx_spi_spi_remove,
1361         .id_table = ifx_id_table
1362 };
1363 
1364 /**
1365  *      ifx_spi_exit    -       module exit
1366  *
1367  *      Unload the module.
1368  */
1369 
1370 static void __exit ifx_spi_exit(void)
1371 {
1372         /* unregister */
1373         spi_unregister_driver(&ifx_spi_driver);
1374         tty_unregister_driver(tty_drv);
1375         put_tty_driver(tty_drv);
1376         unregister_reboot_notifier(&ifx_modem_reboot_notifier_block);
1377 }
1378 
1379 /**
1380  *      ifx_spi_init            -       module entry point
1381  *
1382  *      Initialise the SPI and tty interfaces for the IFX SPI driver
1383  *      We need to initialize upper-edge spi driver after the tty
1384  *      driver because otherwise the spi probe will race
1385  */
1386 
1387 static int __init ifx_spi_init(void)
1388 {
1389         int result;
1390 
1391         tty_drv = alloc_tty_driver(1);
1392         if (!tty_drv) {
1393                 pr_err("%s: alloc_tty_driver failed", DRVNAME);
1394                 return -ENOMEM;
1395         }
1396 
1397         tty_drv->driver_name = DRVNAME;
1398         tty_drv->name = TTYNAME;
1399         tty_drv->minor_start = IFX_SPI_TTY_ID;
1400         tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
1401         tty_drv->subtype = SERIAL_TYPE_NORMAL;
1402         tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1403         tty_drv->init_termios = tty_std_termios;
1404 
1405         tty_set_operations(tty_drv, &ifx_spi_serial_ops);
1406 
1407         result = tty_register_driver(tty_drv);
1408         if (result) {
1409                 pr_err("%s: tty_register_driver failed(%d)",
1410                         DRVNAME, result);
1411                 goto err_free_tty;
1412         }
1413 
1414         result = spi_register_driver(&ifx_spi_driver);
1415         if (result) {
1416                 pr_err("%s: spi_register_driver failed(%d)",
1417                         DRVNAME, result);
1418                 goto err_unreg_tty;
1419         }
1420 
1421         result = register_reboot_notifier(&ifx_modem_reboot_notifier_block);
1422         if (result) {
1423                 pr_err("%s: register ifx modem reboot notifier failed(%d)",
1424                         DRVNAME, result);
1425                 goto err_unreg_spi;
1426         }
1427 
1428         return 0;
1429 err_unreg_spi:
1430         spi_unregister_driver(&ifx_spi_driver);
1431 err_unreg_tty:
1432         tty_unregister_driver(tty_drv);
1433 err_free_tty:
1434         put_tty_driver(tty_drv);
1435 
1436         return result;
1437 }
1438 
1439 module_init(ifx_spi_init);
1440 module_exit(ifx_spi_exit);
1441 
1442 MODULE_AUTHOR("Intel");
1443 MODULE_DESCRIPTION("IFX6x60 spi driver");
1444 MODULE_LICENSE("GPL");
1445 MODULE_INFO(Version, "0.1-IFX6x60");
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root/drivers/tty/serial/ifx6x60.c

DEFINITIONS
