drivers/spi/spi_imx.c

   1 /*
   2  * drivers/spi/spi_imx.c
   3  *
   4  * Copyright (C) 2006 SWAPP
   5  *      Andrea Paterniani <a.paterniani@swapp-eng.it>
   6  *
   7  * Initial version inspired by:
   8  *      linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  */
  20
  21 #include <linux/init.h>
  22 #include <linux/module.h>
  23 #include <linux/device.h>
  24 #include <linux/ioport.h>
  25 #include <linux/errno.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/dma-mapping.h>
  29 #include <linux/spi/spi.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/delay.h>
  32 #include <linux/clk.h>
  33
  34 #include <asm/io.h>
  35 #include <asm/irq.h>
  36 #include <asm/delay.h>
  37
  38 #include <mach/hardware.h>
  39 #include <mach/imx-dma.h>
  40 #include <mach/spi_imx.h>
  41
  42 /*-------------------------------------------------------------------------*/
  43 /* SPI Registers offsets from peripheral base address */
  44 #define SPI_RXDATA              (0x00)
  45 #define SPI_TXDATA              (0x04)
  46 #define SPI_CONTROL             (0x08)
  47 #define SPI_INT_STATUS          (0x0C)
  48 #define SPI_TEST                (0x10)
  49 #define SPI_PERIOD              (0x14)
  50 #define SPI_DMA                 (0x18)
  51 #define SPI_RESET               (0x1C)
  52
  53 /* SPI Control Register Bit Fields & Masks */
  54 #define SPI_CONTROL_BITCOUNT_MASK       (0xF)           /* Bit Count Mask */
  55 #define SPI_CONTROL_BITCOUNT(n)         (((n) - 1) & SPI_CONTROL_BITCOUNT_MASK)
  56 #define SPI_CONTROL_POL                 (0x1 << 4)      /* Clock Polarity Mask */
  57 #define SPI_CONTROL_POL_ACT_HIGH        (0x0 << 4)      /* Active high pol. (0=idle) */
  58 #define SPI_CONTROL_POL_ACT_LOW         (0x1 << 4)      /* Active low pol. (1=idle) */
  59 #define SPI_CONTROL_PHA                 (0x1 << 5)      /* Clock Phase Mask */
  60 #define SPI_CONTROL_PHA_0               (0x0 << 5)      /* Clock Phase 0 */
  61 #define SPI_CONTROL_PHA_1               (0x1 << 5)      /* Clock Phase 1 */
  62 #define SPI_CONTROL_SSCTL               (0x1 << 6)      /* /SS Waveform Select Mask */
  63 #define SPI_CONTROL_SSCTL_0             (0x0 << 6)      /* Master: /SS stays low between SPI burst
  64                                                            Slave: RXFIFO advanced by BIT_COUNT */
  65 #define SPI_CONTROL_SSCTL_1             (0x1 << 6)      /* Master: /SS insert pulse between SPI burst
  66                                                            Slave: RXFIFO advanced by /SS rising edge */
  67 #define SPI_CONTROL_SSPOL               (0x1 << 7)      /* /SS Polarity Select Mask */
  68 #define SPI_CONTROL_SSPOL_ACT_LOW       (0x0 << 7)      /* /SS Active low */
  69 #define SPI_CONTROL_SSPOL_ACT_HIGH      (0x1 << 7)      /* /SS Active high */
  70 #define SPI_CONTROL_XCH                 (0x1 << 8)      /* Exchange */
  71 #define SPI_CONTROL_SPIEN               (0x1 << 9)      /* SPI Module Enable */
  72 #define SPI_CONTROL_MODE                (0x1 << 10)     /* SPI Mode Select Mask */
  73 #define SPI_CONTROL_MODE_SLAVE          (0x0 << 10)     /* SPI Mode Slave */
  74 #define SPI_CONTROL_MODE_MASTER         (0x1 << 10)     /* SPI Mode Master */
  75 #define SPI_CONTROL_DRCTL               (0x3 << 11)     /* /SPI_RDY Control Mask */
  76 #define SPI_CONTROL_DRCTL_0             (0x0 << 11)     /* Ignore /SPI_RDY */
  77 #define SPI_CONTROL_DRCTL_1             (0x1 << 11)     /* /SPI_RDY falling edge triggers input */
  78 #define SPI_CONTROL_DRCTL_2             (0x2 << 11)     /* /SPI_RDY active low level triggers input */
  79 #define SPI_CONTROL_DATARATE            (0x7 << 13)     /* Data Rate Mask */
  80 #define SPI_PERCLK2_DIV_MIN             (0)             /* PERCLK2:4 */
  81 #define SPI_PERCLK2_DIV_MAX             (7)             /* PERCLK2:512 */
  82 #define SPI_CONTROL_DATARATE_MIN        (SPI_PERCLK2_DIV_MAX << 13)
  83 #define SPI_CONTROL_DATARATE_MAX        (SPI_PERCLK2_DIV_MIN << 13)
  84 #define SPI_CONTROL_DATARATE_BAD        (SPI_CONTROL_DATARATE_MIN + 1)
  85
  86 /* SPI Interrupt/Status Register Bit Fields & Masks */
  87 #define SPI_STATUS_TE   (0x1 << 0)      /* TXFIFO Empty Status */
  88 #define SPI_STATUS_TH   (0x1 << 1)      /* TXFIFO Half Status */
  89 #define SPI_STATUS_TF   (0x1 << 2)      /* TXFIFO Full Status */
  90 #define SPI_STATUS_RR   (0x1 << 3)      /* RXFIFO Data Ready Status */
  91 #define SPI_STATUS_RH   (0x1 << 4)      /* RXFIFO Half Status */
  92 #define SPI_STATUS_RF   (0x1 << 5)      /* RXFIFO Full Status */
  93 #define SPI_STATUS_RO   (0x1 << 6)      /* RXFIFO Overflow */
  94 #define SPI_STATUS_BO   (0x1 << 7)      /* Bit Count Overflow */
  95 #define SPI_STATUS      (0xFF)          /* SPI Status Mask */
  96 #define SPI_INTEN_TE    (0x1 << 8)      /* TXFIFO Empty Interrupt Enable */
  97 #define SPI_INTEN_TH    (0x1 << 9)      /* TXFIFO Half Interrupt Enable */
  98 #define SPI_INTEN_TF    (0x1 << 10)     /* TXFIFO Full Interrupt Enable */
  99 #define SPI_INTEN_RE    (0x1 << 11)     /* RXFIFO Data Ready Interrupt Enable */
 100 #define SPI_INTEN_RH    (0x1 << 12)     /* RXFIFO Half Interrupt Enable */
 101 #define SPI_INTEN_RF    (0x1 << 13)     /* RXFIFO Full Interrupt Enable */
 102 #define SPI_INTEN_RO    (0x1 << 14)     /* RXFIFO Overflow Interrupt Enable */
 103 #define SPI_INTEN_BO    (0x1 << 15)     /* Bit Count Overflow Interrupt Enable */
 104 #define SPI_INTEN       (0xFF << 8)     /* SPI Interrupt Enable Mask */
 105
 106 /* SPI Test Register Bit Fields & Masks */
 107 #define SPI_TEST_TXCNT          (0xF << 0)      /* TXFIFO Counter */
 108 #define SPI_TEST_RXCNT_LSB      (4)             /* RXFIFO Counter LSB */
 109 #define SPI_TEST_RXCNT          (0xF << 4)      /* RXFIFO Counter */
 110 #define SPI_TEST_SSTATUS        (0xF << 8)      /* State Machine Status */
 111 #define SPI_TEST_LBC            (0x1 << 14)     /* Loop Back Control */
 112
 113 /* SPI Period Register Bit Fields & Masks */
 114 #define SPI_PERIOD_WAIT         (0x7FFF << 0)   /* Wait Between Transactions */
 115 #define SPI_PERIOD_MAX_WAIT     (0x7FFF)        /* Max Wait Between
 116                                                         Transactions */
 117 #define SPI_PERIOD_CSRC         (0x1 << 15)     /* Period Clock Source Mask */
 118 #define SPI_PERIOD_CSRC_BCLK    (0x0 << 15)     /* Period Clock Source is
 119                                                         Bit Clock */
 120 #define SPI_PERIOD_CSRC_32768   (0x1 << 15)     /* Period Clock Source is
 121                                                         32.768 KHz Clock */
 122
 123 /* SPI DMA Register Bit Fields & Masks */
 124 #define SPI_DMA_RHDMA   (0x1 << 4)      /* RXFIFO Half Status */
 125 #define SPI_DMA_RFDMA   (0x1 << 5)      /* RXFIFO Full Status */
 126 #define SPI_DMA_TEDMA   (0x1 << 6)      /* TXFIFO Empty Status */
 127 #define SPI_DMA_THDMA   (0x1 << 7)      /* TXFIFO Half Status */
 128 #define SPI_DMA_RHDEN   (0x1 << 12)     /* RXFIFO Half DMA Request Enable */
 129 #define SPI_DMA_RFDEN   (0x1 << 13)     /* RXFIFO Full DMA Request Enable */
 130 #define SPI_DMA_TEDEN   (0x1 << 14)     /* TXFIFO Empty DMA Request Enable */
 131 #define SPI_DMA_THDEN   (0x1 << 15)     /* TXFIFO Half DMA Request Enable */
 132
 133 /* SPI Soft Reset Register Bit Fields & Masks */
 134 #define SPI_RESET_START (0x1)           /* Start */
 135
 136 /* Default SPI configuration values */
 137 #define SPI_DEFAULT_CONTROL             \
 138 (                                       \
 139         SPI_CONTROL_BITCOUNT(16) |      \
 140         SPI_CONTROL_POL_ACT_HIGH |      \
 141         SPI_CONTROL_PHA_0 |             \
 142         SPI_CONTROL_SPIEN |             \
 143         SPI_CONTROL_SSCTL_1 |           \
 144         SPI_CONTROL_MODE_MASTER |       \
 145         SPI_CONTROL_DRCTL_0 |           \
 146         SPI_CONTROL_DATARATE_MIN        \
 147 )
 148 #define SPI_DEFAULT_ENABLE_LOOPBACK     (0)
 149 #define SPI_DEFAULT_ENABLE_DMA          (0)
 150 #define SPI_DEFAULT_PERIOD_WAIT         (8)
 151 /*-------------------------------------------------------------------------*/
 152
 153
 154 /*-------------------------------------------------------------------------*/
 155 /* TX/RX SPI FIFO size */
 156 #define SPI_FIFO_DEPTH                  (8)
 157 #define SPI_FIFO_BYTE_WIDTH             (2)
 158 #define SPI_FIFO_OVERFLOW_MARGIN        (2)
 159
 160 /* DMA burst length for half full/empty request trigger */
 161 #define SPI_DMA_BLR                     (SPI_FIFO_DEPTH * SPI_FIFO_BYTE_WIDTH / 2)
 162
 163 /* Dummy char output to achieve reads.
 164    Choosing something different from all zeroes may help pattern recogition
 165    for oscilloscope analysis, but may break some drivers. */
 166 #define SPI_DUMMY_u8                    0
 167 #define SPI_DUMMY_u16                   ((SPI_DUMMY_u8 << 8) | SPI_DUMMY_u8)
 168 #define SPI_DUMMY_u32                   ((SPI_DUMMY_u16 << 16) | SPI_DUMMY_u16)
 169
 170 /**
 171  * Macro to change a u32 field:
 172  * @r : register to edit
 173  * @m : bit mask
 174  * @v : new value for the field correctly bit-alligned
 175 */
 176 #define u32_EDIT(r, m, v)               r = (r & ~(m)) | (v)
 177
 178 /* Message state */
 179 #define START_STATE                     ((void*)0)
 180 #define RUNNING_STATE                   ((void*)1)
 181 #define DONE_STATE                      ((void*)2)
 182 #define ERROR_STATE                     ((void*)-1)
 183
 184 /* Queue state */
 185 #define QUEUE_RUNNING                   (0)
 186 #define QUEUE_STOPPED                   (1)
 187
 188 #define IS_DMA_ALIGNED(x)               (((u32)(x) & 0x03) == 0)
 189 #define DMA_ALIGNMENT                   4
 190 /*-------------------------------------------------------------------------*/
 191
 192
 193 /*-------------------------------------------------------------------------*/
 194 /* Driver data structs */
 195
 196 /* Context */
 197 struct driver_data {
 198         /* Driver model hookup */
 199         struct platform_device *pdev;
 200
 201         /* SPI framework hookup */
 202         struct spi_master *master;
 203
 204         /* IMX hookup */
 205         struct spi_imx_master *master_info;
 206
 207         /* Memory resources and SPI regs virtual address */
 208         struct resource *ioarea;
 209         void __iomem *regs;
 210
 211         /* SPI RX_DATA physical address */
 212         dma_addr_t rd_data_phys;
 213
 214         /* Driver message queue */
 215         struct workqueue_struct *workqueue;
 216         struct work_struct work;
 217         spinlock_t lock;
 218         struct list_head queue;
 219         int busy;
 220         int run;
 221
 222         /* Message Transfer pump */
 223         struct tasklet_struct pump_transfers;
 224
 225         /* Current message, transfer and state */
 226         struct spi_message *cur_msg;
 227         struct spi_transfer *cur_transfer;
 228         struct chip_data *cur_chip;
 229
 230         /* Rd / Wr buffers pointers */
 231         size_t len;
 232         void *tx;
 233         void *tx_end;
 234         void *rx;
 235         void *rx_end;
 236
 237         u8 rd_only;
 238         u8 n_bytes;
 239         int cs_change;
 240
 241         /* Function pointers */
 242         irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
 243         void (*cs_control)(u32 command);
 244
 245         /* DMA setup */
 246         int rx_channel;
 247         int tx_channel;
 248         dma_addr_t rx_dma;
 249         dma_addr_t tx_dma;
 250         int rx_dma_needs_unmap;
 251         int tx_dma_needs_unmap;
 252         size_t tx_map_len;
 253         u32 dummy_dma_buf ____cacheline_aligned;
 254
 255         struct clk *clk;
 256 };
 257
 258 /* Runtime state */
 259 struct chip_data {
 260         u32 control;
 261         u32 period;
 262         u32 test;
 263
 264         u8 enable_dma:1;
 265         u8 bits_per_word;
 266         u8 n_bytes;
 267         u32 max_speed_hz;
 268
 269         void (*cs_control)(u32 command);
 270 };
 271 /*-------------------------------------------------------------------------*/
 272
 273
 274 static void pump_messages(struct work_struct *work);
 275
 276 static void flush(struct driver_data *drv_data)
 277 {
 278         void __iomem *regs = drv_data->regs;
 279         u32 control;
 280
 281         dev_dbg(&drv_data->pdev->dev, "flush\n");
 282
 283         /* Wait for end of transaction */
 284         do {
 285                 control = readl(regs + SPI_CONTROL);
 286         } while (control & SPI_CONTROL_XCH);
 287
 288         /* Release chip select if requested, transfer delays are
 289            handled in pump_transfers */
 290         if (drv_data->cs_change)
 291                 drv_data->cs_control(SPI_CS_DEASSERT);
 292
 293         /* Disable SPI to flush FIFOs */
 294         writel(control & ~SPI_CONTROL_SPIEN, regs + SPI_CONTROL);
 295         writel(control, regs + SPI_CONTROL);
 296 }
 297
 298 static void restore_state(struct driver_data *drv_data)
 299 {
 300         void __iomem *regs = drv_data->regs;
 301         struct chip_data *chip = drv_data->cur_chip;
 302
 303         /* Load chip registers */
 304         dev_dbg(&drv_data->pdev->dev,
 305                 "restore_state\n"
 306                 "    test    = 0x%08X\n"
 307                 "    control = 0x%08X\n",
 308                 chip->test,
 309                 chip->control);
 310         writel(chip->test, regs + SPI_TEST);
 311         writel(chip->period, regs + SPI_PERIOD);
 312         writel(0, regs + SPI_INT_STATUS);
 313         writel(chip->control, regs + SPI_CONTROL);
 314 }
 315
 316 static void null_cs_control(u32 command)
 317 {
 318 }
 319
 320 static inline u32 data_to_write(struct driver_data *drv_data)
 321 {
 322         return ((u32)(drv_data->tx_end - drv_data->tx)) / drv_data->n_bytes;
 323 }
 324
 325 static inline u32 data_to_read(struct driver_data *drv_data)
 326 {
 327         return ((u32)(drv_data->rx_end - drv_data->rx)) / drv_data->n_bytes;
 328 }
 329
 330 static int write(struct driver_data *drv_data)
 331 {
 332         void __iomem *regs = drv_data->regs;
 333         void *tx = drv_data->tx;
 334         void *tx_end = drv_data->tx_end;
 335         u8 n_bytes = drv_data->n_bytes;
 336         u32 remaining_writes;
 337         u32 fifo_avail_space;
 338         u32 n;
 339         u16 d;
 340
 341         /* Compute how many fifo writes to do */
 342         remaining_writes = (u32)(tx_end - tx) / n_bytes;
 343         fifo_avail_space = SPI_FIFO_DEPTH -
 344                                 (readl(regs + SPI_TEST) & SPI_TEST_TXCNT);
 345         if (drv_data->rx && (fifo_avail_space > SPI_FIFO_OVERFLOW_MARGIN))
 346                 /* Fix misunderstood receive overflow */
 347                 fifo_avail_space -= SPI_FIFO_OVERFLOW_MARGIN;
 348         n = min(remaining_writes, fifo_avail_space);
 349
 350         dev_dbg(&drv_data->pdev->dev,
 351                 "write type %s\n"
 352                 "    remaining writes = %d\n"
 353                 "    fifo avail space = %d\n"
 354                 "    fifo writes      = %d\n",
 355                 (n_bytes == 1) ? "u8" : "u16",
 356                 remaining_writes,
 357                 fifo_avail_space,
 358                 n);
 359
 360         if (n > 0) {
 361                 /* Fill SPI TXFIFO */
 362                 if (drv_data->rd_only) {
 363                         tx += n * n_bytes;
 364                         while (n--)
 365                                 writel(SPI_DUMMY_u16, regs + SPI_TXDATA);
 366                 } else {
 367                         if (n_bytes == 1) {
 368                                 while (n--) {
 369                                         d = *(u8*)tx;
 370                                         writel(d, regs + SPI_TXDATA);
 371                                         tx += 1;
 372                                 }
 373                         } else {
 374                                 while (n--) {
 375                                         d = *(u16*)tx;
 376                                         writel(d, regs + SPI_TXDATA);
 377                                         tx += 2;
 378                                 }
 379                         }
 380                 }
 381
 382                 /* Trigger transfer */
 383                 writel(readl(regs + SPI_CONTROL) | SPI_CONTROL_XCH,
 384                         regs + SPI_CONTROL);
 385
 386                 /* Update tx pointer */
 387                 drv_data->tx = tx;
 388         }
 389
 390         return (tx >= tx_end);
 391 }
 392
 393 static int read(struct driver_data *drv_data)
 394 {
 395         void __iomem *regs = drv_data->regs;
 396         void *rx = drv_data->rx;
 397         void *rx_end = drv_data->rx_end;
 398         u8 n_bytes = drv_data->n_bytes;
 399         u32 remaining_reads;
 400         u32 fifo_rxcnt;
 401         u32 n;
 402         u16 d;
 403
 404         /* Compute how many fifo reads to do */
 405         remaining_reads = (u32)(rx_end - rx) / n_bytes;
 406         fifo_rxcnt = (readl(regs + SPI_TEST) & SPI_TEST_RXCNT) >>
 407                         SPI_TEST_RXCNT_LSB;
 408         n = min(remaining_reads, fifo_rxcnt);
 409
 410         dev_dbg(&drv_data->pdev->dev,
 411                 "read type %s\n"
 412                 "    remaining reads = %d\n"
 413                 "    fifo rx count   = %d\n"
 414                 "    fifo reads      = %d\n",
 415                 (n_bytes == 1) ? "u8" : "u16",
 416                 remaining_reads,
 417                 fifo_rxcnt,
 418                 n);
 419
 420         if (n > 0) {
 421                 /* Read SPI RXFIFO */
 422                 if (n_bytes == 1) {
 423                         while (n--) {
 424                                 d = readl(regs + SPI_RXDATA);
 425                                 *((u8*)rx) = d;
 426                                 rx += 1;
 427                         }
 428                 } else {
 429                         while (n--) {
 430                                 d = readl(regs + SPI_RXDATA);
 431                                 *((u16*)rx) = d;
 432                                 rx += 2;
 433                         }
 434                 }
 435
 436                 /* Update rx pointer */
 437                 drv_data->rx = rx;
 438         }
 439
 440         return (rx >= rx_end);
 441 }
 442
 443 static void *next_transfer(struct driver_data *drv_data)
 444 {
 445         struct spi_message *msg = drv_data->cur_msg;
 446         struct spi_transfer *trans = drv_data->cur_transfer;
 447
 448         /* Move to next transfer */
 449         if (trans->transfer_list.next != &msg->transfers) {
 450                 drv_data->cur_transfer =
 451                         list_entry(trans->transfer_list.next,
 452                                         struct spi_transfer,
 453                                         transfer_list);
 454                 return RUNNING_STATE;
 455         }
 456
 457         return DONE_STATE;
 458 }
 459
 460 static int map_dma_buffers(struct driver_data *drv_data)
 461 {
 462         struct spi_message *msg;
 463         struct device *dev;
 464         void *buf;
 465
 466         drv_data->rx_dma_needs_unmap = 0;
 467         drv_data->tx_dma_needs_unmap = 0;
 468
 469         if (!drv_data->master_info->enable_dma ||
 470                 !drv_data->cur_chip->enable_dma)
 471                         return -1;
 472
 473         msg = drv_data->cur_msg;
 474         dev = &msg->spi->dev;
 475         if (msg->is_dma_mapped) {
 476                 if (drv_data->tx_dma)
 477                         /* The caller provided at least dma and cpu virtual
 478                            address for write; pump_transfers() will consider the
 479                            transfer as write only if cpu rx virtual address is
 480                            NULL */
 481                         return 0;
 482
 483                 if (drv_data->rx_dma) {
 484                         /* The caller provided dma and cpu virtual address to
 485                            performe read only transfer -->
 486                            use drv_data->dummy_dma_buf for dummy writes to
 487                            achive reads */
 488                         buf = &drv_data->dummy_dma_buf;
 489                         drv_data->tx_map_len = sizeof(drv_data->dummy_dma_buf);
 490                         drv_data->tx_dma = dma_map_single(dev,
 491                                                         buf,
 492                                                         drv_data->tx_map_len,
 493                                                         DMA_TO_DEVICE);
 494                         if (dma_mapping_error(dev, drv_data->tx_dma))
 495                                 return -1;
 496
 497                         drv_data->tx_dma_needs_unmap = 1;
 498
 499                         /* Flags transfer as rd_only for pump_transfers() DMA
 500                            regs programming (should be redundant) */
 501                         drv_data->tx = NULL;
 502
 503                         return 0;
 504                 }
 505         }
 506
 507         if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
 508                 return -1;
 509
 510         if (drv_data->tx == NULL) {
 511                 /* Read only message --> use drv_data->dummy_dma_buf for dummy
 512                    writes to achive reads */
 513                 buf = &drv_data->dummy_dma_buf;
 514                 drv_data->tx_map_len = sizeof(drv_data->dummy_dma_buf);
 515         } else {
 516                 buf = drv_data->tx;
 517                 drv_data->tx_map_len = drv_data->len;
 518         }
 519         drv_data->tx_dma = dma_map_single(dev,
 520                                         buf,
 521                                         drv_data->tx_map_len,
 522                                         DMA_TO_DEVICE);
 523         if (dma_mapping_error(dev, drv_data->tx_dma))
 524                 return -1;
 525         drv_data->tx_dma_needs_unmap = 1;
 526
 527         /* NULL rx means write-only transfer and no map needed
 528          * since rx DMA will not be used */
 529         if (drv_data->rx) {
 530                 buf = drv_data->rx;
 531                 drv_data->rx_dma = dma_map_single(dev,
 532                                                 buf,
 533                                                 drv_data->len,
 534                                                 DMA_FROM_DEVICE);
 535                 if (dma_mapping_error(dev, drv_data->rx_dma)) {
 536                         if (drv_data->tx_dma) {
 537                                 dma_unmap_single(dev,
 538                                                 drv_data->tx_dma,
 539                                                 drv_data->tx_map_len,
 540                                                 DMA_TO_DEVICE);
 541                                 drv_data->tx_dma_needs_unmap = 0;
 542                         }
 543                         return -1;
 544                 }
 545                 drv_data->rx_dma_needs_unmap = 1;
 546         }
 547
 548         return 0;
 549 }
 550
 551 static void unmap_dma_buffers(struct driver_data *drv_data)
 552 {
 553         struct spi_message *msg = drv_data->cur_msg;
 554         struct device *dev = &msg->spi->dev;
 555
 556         if (drv_data->rx_dma_needs_unmap) {
 557                 dma_unmap_single(dev,
 558                                 drv_data->rx_dma,
 559                                 drv_data->len,
 560                                 DMA_FROM_DEVICE);
 561                 drv_data->rx_dma_needs_unmap = 0;
 562         }
 563         if (drv_data->tx_dma_needs_unmap) {
 564                 dma_unmap_single(dev,
 565                                 drv_data->tx_dma,
 566                                 drv_data->tx_map_len,
 567                                 DMA_TO_DEVICE);
 568                 drv_data->tx_dma_needs_unmap = 0;
 569         }
 570 }
 571
 572 /* Caller already set message->status (dma is already blocked) */
 573 static void giveback(struct spi_message *message, struct driver_data *drv_data)
 574 {
 575         void __iomem *regs = drv_data->regs;
 576
 577         /* Bring SPI to sleep; restore_state() and pump_transfer()
 578            will do new setup */
 579         writel(0, regs + SPI_INT_STATUS);
 580         writel(0, regs + SPI_DMA);
 581
 582         /* Unconditioned deselct */
 583         drv_data->cs_control(SPI_CS_DEASSERT);
 584
 585         message->state = NULL;
 586         if (message->complete)
 587                 message->complete(message->context);
 588
 589         drv_data->cur_msg = NULL;
 590         drv_data->cur_transfer = NULL;
 591         drv_data->cur_chip = NULL;
 592         queue_work(drv_data->workqueue, &drv_data->work);
 593 }
 594
 595 static void dma_err_handler(int channel, void *data, int errcode)
 596 {
 597         struct driver_data *drv_data = data;
 598         struct spi_message *msg = drv_data->cur_msg;
 599
 600         dev_dbg(&drv_data->pdev->dev, "dma_err_handler\n");
 601
 602         /* Disable both rx and tx dma channels */
 603         imx_dma_disable(drv_data->rx_channel);
 604         imx_dma_disable(drv_data->tx_channel);
 605         unmap_dma_buffers(drv_data);
 606
 607         flush(drv_data);
 608
 609         msg->state = ERROR_STATE;
 610         tasklet_schedule(&drv_data->pump_transfers);
 611 }
 612
 613 static void dma_tx_handler(int channel, void *data)
 614 {
 615         struct driver_data *drv_data = data;
 616
 617         dev_dbg(&drv_data->pdev->dev, "dma_tx_handler\n");
 618
 619         imx_dma_disable(channel);
 620
 621         /* Now waits for TX FIFO empty */
 622         writel(SPI_INTEN_TE, drv_data->regs + SPI_INT_STATUS);
 623 }
 624
 625 static irqreturn_t dma_transfer(struct driver_data *drv_data)
 626 {
 627         u32 status;
 628         struct spi_message *msg = drv_data->cur_msg;
 629         void __iomem *regs = drv_data->regs;
 630
 631         status = readl(regs + SPI_INT_STATUS);
 632
 633         if ((status & (SPI_INTEN_RO | SPI_STATUS_RO))
 634                         == (SPI_INTEN_RO | SPI_STATUS_RO)) {
 635                 writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
 636
 637                 imx_dma_disable(drv_data->tx_channel);
 638                 imx_dma_disable(drv_data->rx_channel);
 639                 unmap_dma_buffers(drv_data);
 640
 641                 flush(drv_data);
 642
 643                 dev_warn(&drv_data->pdev->dev,
 644                                 "dma_transfer - fifo overun\n");
 645
 646                 msg->state = ERROR_STATE;
 647                 tasklet_schedule(&drv_data->pump_transfers);
 648
 649                 return IRQ_HANDLED;
 650         }
 651
 652         if (status & SPI_STATUS_TE) {
 653                 writel(status & ~SPI_INTEN_TE, regs + SPI_INT_STATUS);
 654
 655                 if (drv_data->rx) {
 656                         /* Wait end of transfer before read trailing data */
 657                         while (readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH)
 658                                 cpu_relax();
 659
 660                         imx_dma_disable(drv_data->rx_channel);
 661                         unmap_dma_buffers(drv_data);
 662
 663                         /* Release chip select if requested, transfer delays are
 664                            handled in pump_transfers() */
 665                         if (drv_data->cs_change)
 666                                 drv_data->cs_control(SPI_CS_DEASSERT);
 667
 668                         /* Calculate number of trailing data and read them */
 669                         dev_dbg(&drv_data->pdev->dev,
 670                                 "dma_transfer - test = 0x%08X\n",
 671                                 readl(regs + SPI_TEST));
 672                         drv_data->rx = drv_data->rx_end -
 673                                         ((readl(regs + SPI_TEST) &
 674                                         SPI_TEST_RXCNT) >>
 675                                         SPI_TEST_RXCNT_LSB)*drv_data->n_bytes;
 676                         read(drv_data);
 677                 } else {
 678                         /* Write only transfer */
 679                         unmap_dma_buffers(drv_data);
 680
 681                         flush(drv_data);
 682                 }
 683
 684                 /* End of transfer, update total byte transfered */
 685                 msg->actual_length += drv_data->len;
 686
 687                 /* Move to next transfer */
 688                 msg->state = next_transfer(drv_data);
 689
 690                 /* Schedule transfer tasklet */
 691                 tasklet_schedule(&drv_data->pump_transfers);
 692
 693                 return IRQ_HANDLED;
 694         }
 695
 696         /* Opps problem detected */
 697         return IRQ_NONE;
 698 }
 699
 700 static irqreturn_t interrupt_wronly_transfer(struct driver_data *drv_data)
 701 {
 702         struct spi_message *msg = drv_data->cur_msg;
 703         void __iomem *regs = drv_data->regs;
 704         u32 status;
 705         irqreturn_t handled = IRQ_NONE;
 706
 707         status = readl(regs + SPI_INT_STATUS);
 708
 709         if (status & SPI_INTEN_TE) {
 710                 /* TXFIFO Empty Interrupt on the last transfered word */
 711                 writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
 712                 dev_dbg(&drv_data->pdev->dev,
 713                         "interrupt_wronly_transfer - end of tx\n");
 714
 715                 flush(drv_data);
 716
 717                 /* Update total byte transfered */
 718                 msg->actual_length += drv_data->len;
 719
 720                 /* Move to next transfer */
 721                 msg->state = next_transfer(drv_data);
 722
 723                 /* Schedule transfer tasklet */
 724                 tasklet_schedule(&drv_data->pump_transfers);
 725
 726                 return IRQ_HANDLED;
 727         } else {
 728                 while (status & SPI_STATUS_TH) {
 729                         dev_dbg(&drv_data->pdev->dev,
 730                                 "interrupt_wronly_transfer - status = 0x%08X\n",
 731                                 status);
 732
 733                         /* Pump data */
 734                         if (write(drv_data)) {
 735                                 /* End of TXFIFO writes,
 736                                    now wait until TXFIFO is empty */
 737                                 writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
 738                                 return IRQ_HANDLED;
 739                         }
 740
 741                         status = readl(regs + SPI_INT_STATUS);
 742
 743                         /* We did something */
 744                         handled = IRQ_HANDLED;
 745                 }
 746         }
 747
 748         return handled;
 749 }
 750
 751 static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 752 {
 753         struct spi_message *msg = drv_data->cur_msg;
 754         void __iomem *regs = drv_data->regs;
 755         u32 status, control;
 756         irqreturn_t handled = IRQ_NONE;
 757         unsigned long limit;
 758
 759         status = readl(regs + SPI_INT_STATUS);
 760
 761         if (status & SPI_INTEN_TE) {
 762                 /* TXFIFO Empty Interrupt on the last transfered word */
 763                 writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
 764                 dev_dbg(&drv_data->pdev->dev,
 765                         "interrupt_transfer - end of tx\n");
 766
 767                 if (msg->state == ERROR_STATE) {
 768                         /* RXFIFO overrun was detected and message aborted */
 769                         flush(drv_data);
 770                 } else {
 771                         /* Wait for end of transaction */
 772                         do {
 773                                 control = readl(regs + SPI_CONTROL);
 774                         } while (control & SPI_CONTROL_XCH);
 775
 776                         /* Release chip select if requested, transfer delays are
 777                            handled in pump_transfers */
 778                         if (drv_data->cs_change)
 779                                 drv_data->cs_control(SPI_CS_DEASSERT);
 780
 781                         /* Read trailing bytes */
 782                         limit = loops_per_jiffy << 1;
 783                         while ((read(drv_data) == 0) && --limit)
 784                                 cpu_relax();
 785
 786                         if (limit == 0)
 787                                 dev_err(&drv_data->pdev->dev,
 788                                         "interrupt_transfer - "
 789                                         "trailing byte read failed\n");
 790                         else
 791                                 dev_dbg(&drv_data->pdev->dev,
 792                                         "interrupt_transfer - end of rx\n");
 793
 794                         /* Update total byte transfered */
 795                         msg->actual_length += drv_data->len;
 796
 797                         /* Move to next transfer */
 798                         msg->state = next_transfer(drv_data);
 799                 }
 800
 801                 /* Schedule transfer tasklet */
 802                 tasklet_schedule(&drv_data->pump_transfers);
 803
 804                 return IRQ_HANDLED;
 805         } else {
 806                 while (status & (SPI_STATUS_TH | SPI_STATUS_RO)) {
 807                         dev_dbg(&drv_data->pdev->dev,
 808                                 "interrupt_transfer - status = 0x%08X\n",
 809                                 status);
 810
 811                         if (status & SPI_STATUS_RO) {
 812                                 /* RXFIFO overrun, abort message end wait
 813                                    until TXFIFO is empty */
 814                                 writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
 815
 816                                 dev_warn(&drv_data->pdev->dev,
 817                                         "interrupt_transfer - fifo overun\n"
 818                                         "    data not yet written = %d\n"
 819                                         "    data not yet read    = %d\n",
 820                                         data_to_write(drv_data),
 821                                         data_to_read(drv_data));
 822
 823                                 msg->state = ERROR_STATE;
 824
 825                                 return IRQ_HANDLED;
 826                         }
 827
 828                         /* Pump data */
 829                         read(drv_data);
 830                         if (write(drv_data)) {
 831                                 /* End of TXFIFO writes,
 832                                    now wait until TXFIFO is empty */
 833                                 writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
 834                                 return IRQ_HANDLED;
 835                         }
 836
 837                         status = readl(regs + SPI_INT_STATUS);
 838
 839                         /* We did something */
 840                         handled = IRQ_HANDLED;
 841                 }
 842         }
 843
 844         return handled;
 845 }
 846
 847 static irqreturn_t spi_int(int irq, void *dev_id)
 848 {
 849         struct driver_data *drv_data = (struct driver_data *)dev_id;
 850
 851         if (!drv_data->cur_msg) {
 852                 dev_err(&drv_data->pdev->dev,
 853                         "spi_int - bad message state\n");
 854                 /* Never fail */
 855                 return IRQ_HANDLED;
 856         }
 857
 858         return drv_data->transfer_handler(drv_data);
 859 }
 860
 861 static inline u32 spi_speed_hz(struct driver_data *drv_data, u32 data_rate)
 862 {
 863         return clk_get_rate(drv_data->clk) / (4 << ((data_rate) >> 13));
 864 }
 865
 866 static u32 spi_data_rate(struct driver_data *drv_data, u32 speed_hz)
 867 {
 868         u32 div;
 869         u32 quantized_hz = clk_get_rate(drv_data->clk) >> 2;
 870
 871         for (div = SPI_PERCLK2_DIV_MIN;
 872                 div <= SPI_PERCLK2_DIV_MAX;
 873                 div++, quantized_hz >>= 1) {
 874                         if (quantized_hz <= speed_hz)
 875                                 /* Max available speed LEQ required speed */
 876                                 return div << 13;
 877         }
 878         return SPI_CONTROL_DATARATE_BAD;
 879 }
 880
 881 static void pump_transfers(unsigned long data)
 882 {
 883         struct driver_data *drv_data = (struct driver_data *)data;
 884         struct spi_message *message;
 885         struct spi_transfer *transfer, *previous;
 886         struct chip_data *chip;
 887         void __iomem *regs;
 888         u32 tmp, control;
 889
 890         dev_dbg(&drv_data->pdev->dev, "pump_transfer\n");
 891
 892         message = drv_data->cur_msg;
 893
 894         /* Handle for abort */
 895         if (message->state == ERROR_STATE) {
 896                 message->status = -EIO;
 897                 giveback(message, drv_data);
 898                 return;
 899         }
 900
 901         /* Handle end of message */
 902         if (message->state == DONE_STATE) {
 903                 message->status = 0;
 904                 giveback(message, drv_data);
 905                 return;
 906         }
 907
 908         chip = drv_data->cur_chip;
 909
 910         /* Delay if requested at end of transfer*/
 911         transfer = drv_data->cur_transfer;
 912         if (message->state == RUNNING_STATE) {
 913                 previous = list_entry(transfer->transfer_list.prev,
 914                                         struct spi_transfer,
 915                                         transfer_list);
 916                 if (previous->delay_usecs)
 917                         udelay(previous->delay_usecs);
 918         } else {
 919                 /* START_STATE */
 920                 message->state = RUNNING_STATE;
 921                 drv_data->cs_control = chip->cs_control;
 922         }
 923
 924         transfer = drv_data->cur_transfer;
 925         drv_data->tx = (void *)transfer->tx_buf;
 926         drv_data->tx_end = drv_data->tx + transfer->len;
 927         drv_data->rx = transfer->rx_buf;
 928         drv_data->rx_end = drv_data->rx + transfer->len;
 929         drv_data->rx_dma = transfer->rx_dma;
 930         drv_data->tx_dma = transfer->tx_dma;
 931         drv_data->len = transfer->len;
 932         drv_data->cs_change = transfer->cs_change;
 933         drv_data->rd_only = (drv_data->tx == NULL);
 934
 935         regs = drv_data->regs;
 936         control = readl(regs + SPI_CONTROL);
 937
 938         /* Bits per word setup */
 939         tmp = transfer->bits_per_word;
 940         if (tmp == 0) {
 941                 /* Use device setup */
 942                 tmp = chip->bits_per_word;
 943                 drv_data->n_bytes = chip->n_bytes;
 944         } else
 945                 /* Use per-transfer setup */
 946                 drv_data->n_bytes = (tmp <= 8) ? 1 : 2;
 947         u32_EDIT(control, SPI_CONTROL_BITCOUNT_MASK, tmp - 1);
 948
 949         /* Speed setup (surely valid because already checked) */
 950         tmp = transfer->speed_hz;
 951         if (tmp == 0)
 952                 tmp = chip->max_speed_hz;
 953         tmp = spi_data_rate(drv_data, tmp);
 954         u32_EDIT(control, SPI_CONTROL_DATARATE, tmp);
 955
 956         writel(control, regs + SPI_CONTROL);
 957
 958         /* Assert device chip-select */
 959         drv_data->cs_control(SPI_CS_ASSERT);
 960
 961         /* DMA cannot read/write SPI FIFOs other than 16 bits at a time; hence
 962            if bits_per_word is less or equal 8 PIO transfers are performed.
 963            Moreover DMA is convinient for transfer length bigger than FIFOs
 964            byte size. */
 965         if ((drv_data->n_bytes == 2) &&
 966                 (drv_data->len > SPI_FIFO_DEPTH*SPI_FIFO_BYTE_WIDTH) &&
 967                 (map_dma_buffers(drv_data) == 0)) {
 968                 dev_dbg(&drv_data->pdev->dev,
 969                         "pump dma transfer\n"
 970                         "    tx      = %p\n"
 971                         "    tx_dma  = %08X\n"
 972                         "    rx      = %p\n"
 973                         "    rx_dma  = %08X\n"
 974                         "    len     = %d\n",
 975                         drv_data->tx,
 976                         (unsigned int)drv_data->tx_dma,
 977                         drv_data->rx,
 978                         (unsigned int)drv_data->rx_dma,
 979                         drv_data->len);
 980
 981                 /* Ensure we have the correct interrupt handler */
 982                 drv_data->transfer_handler = dma_transfer;
 983
 984                 /* Trigger transfer */
 985                 writel(readl(regs + SPI_CONTROL) | SPI_CONTROL_XCH,
 986                         regs + SPI_CONTROL);
 987
 988                 /* Setup tx DMA */
 989                 if (drv_data->tx)
 990                         /* Linear source address */
 991                         CCR(drv_data->tx_channel) =
 992                                 CCR_DMOD_FIFO |
 993                                 CCR_SMOD_LINEAR |
 994                                 CCR_SSIZ_32 | CCR_DSIZ_16 |
 995                                 CCR_REN;
 996                 else
 997                         /* Read only transfer -> fixed source address for
 998                            dummy write to achive read */
 999                         CCR(drv_data->tx_channel) =
1000                                 CCR_DMOD_FIFO |
1001                                 CCR_SMOD_FIFO |
1002                                 CCR_SSIZ_32 | CCR_DSIZ_16 |
1003                                 CCR_REN;
1004
1005                 imx_dma_setup_single(
1006                         drv_data->tx_channel,
1007                         drv_data->tx_dma,
1008                         drv_data->len,
1009                         drv_data->rd_data_phys + 4,
1010                         DMA_MODE_WRITE);
1011
1012                 if (drv_data->rx) {
1013                         /* Setup rx DMA for linear destination address */
1014                         CCR(drv_data->rx_channel) =
1015                                 CCR_DMOD_LINEAR |
1016                                 CCR_SMOD_FIFO |
1017                                 CCR_DSIZ_32 | CCR_SSIZ_16 |
1018                                 CCR_REN;
1019                         imx_dma_setup_single(
1020                                 drv_data->rx_channel,
1021                                 drv_data->rx_dma,
1022                                 drv_data->len,
1023                                 drv_data->rd_data_phys,
1024                                 DMA_MODE_READ);
1025                         imx_dma_enable(drv_data->rx_channel);
1026
1027                         /* Enable SPI interrupt */
1028                         writel(SPI_INTEN_RO, regs + SPI_INT_STATUS);
1029
1030                         /* Set SPI to request DMA service on both
1031                            Rx and Tx half fifo watermark */
1032                         writel(SPI_DMA_RHDEN | SPI_DMA_THDEN, regs + SPI_DMA);
1033                 } else
1034                         /* Write only access -> set SPI to request DMA
1035                            service on Tx half fifo watermark */
1036                         writel(SPI_DMA_THDEN, regs + SPI_DMA);
1037
1038                 imx_dma_enable(drv_data->tx_channel);
1039         } else {
1040                 dev_dbg(&drv_data->pdev->dev,
1041                         "pump pio transfer\n"
1042                         "    tx      = %p\n"
1043                         "    rx      = %p\n"
1044                         "    len     = %d\n",
1045                         drv_data->tx,
1046                         drv_data->rx,
1047                         drv_data->len);
1048
1049                 /* Ensure we have the correct interrupt handler */
1050                 if (drv_data->rx)
1051                         drv_data->transfer_handler = interrupt_transfer;
1052                 else
1053                         drv_data->transfer_handler = interrupt_wronly_transfer;
1054
1055                 /* Enable SPI interrupt */
1056                 if (drv_data->rx)
1057                         writel(SPI_INTEN_TH | SPI_INTEN_RO,
1058                                 regs + SPI_INT_STATUS);
1059                 else
1060                         writel(SPI_INTEN_TH, regs + SPI_INT_STATUS);
1061         }
1062 }
1063
1064 static void pump_messages(struct work_struct *work)
1065 {
1066         struct driver_data *drv_data =
1067                                 container_of(work, struct driver_data, work);
1068         unsigned long flags;
1069
1070         /* Lock queue and check for queue work */
1071         spin_lock_irqsave(&drv_data->lock, flags);
1072         if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
1073                 drv_data->busy = 0;
1074                 spin_unlock_irqrestore(&drv_data->lock, flags);
1075                 return;
1076         }
1077
1078         /* Make sure we are not already running a message */
1079         if (drv_data->cur_msg) {
1080                 spin_unlock_irqrestore(&drv_data->lock, flags);
1081                 return;
1082         }
1083
1084         /* Extract head of queue */
1085         drv_data->cur_msg = list_entry(drv_data->queue.next,
1086                                         struct spi_message, queue);
1087         list_del_init(&drv_data->cur_msg->queue);
1088         drv_data->busy = 1;
1089         spin_unlock_irqrestore(&drv_data->lock, flags);
1090
1091         /* Initial message state */
1092         drv_data->cur_msg->state = START_STATE;
1093         drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
1094                                                 struct spi_transfer,
1095                                                 transfer_list);
1096
1097         /* Setup the SPI using the per chip configuration */
1098         drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
1099         restore_state(drv_data);
1100
1101         /* Mark as busy and launch transfers */
1102         tasklet_schedule(&drv_data->pump_transfers);
1103 }
1104
1105 static int transfer(struct spi_device *spi, struct spi_message *msg)
1106 {
1107         struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1108         u32 min_speed_hz, max_speed_hz, tmp;
1109         struct spi_transfer *trans;
1110         unsigned long flags;
1111
1112         msg->actual_length = 0;
1113
1114         /* Per transfer setup check */
1115         min_speed_hz = spi_speed_hz(drv_data, SPI_CONTROL_DATARATE_MIN);
1116         max_speed_hz = spi->max_speed_hz;
1117         list_for_each_entry(trans, &msg->transfers, transfer_list) {
1118                 tmp = trans->bits_per_word;
1119                 if (tmp > 16) {
1120                         dev_err(&drv_data->pdev->dev,
1121                                 "message rejected : "
1122                                 "invalid transfer bits_per_word (%d bits)\n",
1123                                 tmp);
1124                         goto msg_rejected;
1125                 }
1126                 tmp = trans->speed_hz;
1127                 if (tmp) {
1128                         if (tmp < min_speed_hz) {
1129                                 dev_err(&drv_data->pdev->dev,
1130                                         "message rejected : "
1131                                         "device min speed (%d Hz) exceeds "
1132                                         "required transfer speed (%d Hz)\n",
1133                                         min_speed_hz,
1134                                         tmp);
1135                                 goto msg_rejected;
1136                         } else if (tmp > max_speed_hz) {
1137                                 dev_err(&drv_data->pdev->dev,
1138                                         "message rejected : "
1139                                         "transfer speed (%d Hz) exceeds "
1140                                         "device max speed (%d Hz)\n",
1141                                         tmp,
1142                                         max_speed_hz);
1143                                 goto msg_rejected;
1144                         }
1145                 }
1146         }
1147
1148         /* Message accepted */
1149         msg->status = -EINPROGRESS;
1150         msg->state = START_STATE;
1151
1152         spin_lock_irqsave(&drv_data->lock, flags);
1153         if (drv_data->run == QUEUE_STOPPED) {
1154                 spin_unlock_irqrestore(&drv_data->lock, flags);
1155                 return -ESHUTDOWN;
1156         }
1157
1158         list_add_tail(&msg->queue, &drv_data->queue);
1159         if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
1160                 queue_work(drv_data->workqueue, &drv_data->work);
1161
1162         spin_unlock_irqrestore(&drv_data->lock, flags);
1163         return 0;
1164
1165 msg_rejected:
1166         /* Message rejected and not queued */
1167         msg->status = -EINVAL;
1168         msg->state = ERROR_STATE;
1169         if (msg->complete)
1170                 msg->complete(msg->context);
1171         return -EINVAL;
1172 }
1173
1174 /* the spi->mode bits understood by this driver: */
1175 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
1176
1177 /* On first setup bad values must free chip_data memory since will cause
1178    spi_new_device to fail. Bad value setup from protocol driver are simply not
1179    applied and notified to the calling driver. */
1180 static int setup(struct spi_device *spi)
1181 {
1182         struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1183         struct spi_imx_chip *chip_info;
1184         struct chip_data *chip;
1185         int first_setup = 0;
1186         u32 tmp;
1187         int status = 0;
1188
1189         if (spi->mode & ~MODEBITS) {
1190                 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
1191                         spi->mode & ~MODEBITS);
1192                 return -EINVAL;
1193         }
1194
1195         /* Get controller data */
1196         chip_info = spi->controller_data;
1197
1198         /* Get controller_state */
1199         chip = spi_get_ctldata(spi);
1200         if (chip == NULL) {
1201                 first_setup = 1;
1202
1203                 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1204                 if (!chip) {
1205                         dev_err(&spi->dev,
1206                                 "setup - cannot allocate controller state\n");
1207                         return -ENOMEM;
1208                 }
1209                 chip->control = SPI_DEFAULT_CONTROL;
1210
1211                 if (chip_info == NULL) {
1212                         /* spi_board_info.controller_data not is supplied */
1213                         chip_info = kzalloc(sizeof(struct spi_imx_chip),
1214                                                 GFP_KERNEL);
1215                         if (!chip_info) {
1216                                 dev_err(&spi->dev,
1217                                         "setup - "
1218                                         "cannot allocate controller data\n");
1219                                 status = -ENOMEM;
1220                                 goto err_first_setup;
1221                         }
1222                         /* Set controller data default value */
1223                         chip_info->enable_loopback =
1224                                                 SPI_DEFAULT_ENABLE_LOOPBACK;
1225                         chip_info->enable_dma = SPI_DEFAULT_ENABLE_DMA;
1226                         chip_info->ins_ss_pulse = 1;
1227                         chip_info->bclk_wait = SPI_DEFAULT_PERIOD_WAIT;
1228                         chip_info->cs_control = null_cs_control;
1229                 }
1230         }
1231
1232         /* Now set controller state based on controller data */
1233
1234         if (first_setup) {
1235                 /* SPI loopback */
1236                 if (chip_info->enable_loopback)
1237                         chip->test = SPI_TEST_LBC;
1238                 else
1239                         chip->test = 0;
1240
1241                 /* SPI dma driven */
1242                 chip->enable_dma = chip_info->enable_dma;
1243
1244                 /* SPI /SS pulse between spi burst */
1245                 if (chip_info->ins_ss_pulse)
1246                         u32_EDIT(chip->control,
1247                                 SPI_CONTROL_SSCTL, SPI_CONTROL_SSCTL_1);
1248                 else
1249                         u32_EDIT(chip->control,
1250                                 SPI_CONTROL_SSCTL, SPI_CONTROL_SSCTL_0);
1251
1252                 /* SPI bclk waits between each bits_per_word spi burst */
1253                 if (chip_info->bclk_wait > SPI_PERIOD_MAX_WAIT) {
1254                         dev_err(&spi->dev,
1255                                 "setup - "
1256                                 "bclk_wait exceeds max allowed (%d)\n",
1257                                 SPI_PERIOD_MAX_WAIT);
1258                         goto err_first_setup;
1259                 }
1260                 chip->period = SPI_PERIOD_CSRC_BCLK |
1261                                 (chip_info->bclk_wait & SPI_PERIOD_WAIT);
1262         }
1263
1264         /* SPI mode */
1265         tmp = spi->mode;
1266         if (tmp & SPI_CS_HIGH) {
1267                 u32_EDIT(chip->control,
1268                                 SPI_CONTROL_SSPOL, SPI_CONTROL_SSPOL_ACT_HIGH);
1269         }
1270         switch (tmp & SPI_MODE_3) {
1271         case SPI_MODE_0:
1272                 tmp = 0;
1273                 break;
1274         case SPI_MODE_1:
1275                 tmp = SPI_CONTROL_PHA_1;
1276                 break;
1277         case SPI_MODE_2:
1278                 tmp = SPI_CONTROL_POL_ACT_LOW;
1279                 break;
1280         default:
1281                 /* SPI_MODE_3 */
1282                 tmp = SPI_CONTROL_PHA_1 | SPI_CONTROL_POL_ACT_LOW;
1283                 break;
1284         }
1285         u32_EDIT(chip->control, SPI_CONTROL_POL | SPI_CONTROL_PHA, tmp);
1286
1287         /* SPI word width */
1288         tmp = spi->bits_per_word;
1289         if (tmp == 0) {
1290                 tmp = 8;
1291                 spi->bits_per_word = 8;
1292         } else if (tmp > 16) {
1293                 status = -EINVAL;
1294                 dev_err(&spi->dev,
1295                         "setup - "
1296                         "invalid bits_per_word (%d)\n",
1297                         tmp);
1298                 if (first_setup)
1299                         goto err_first_setup;
1300                 else {
1301                         /* Undo setup using chip as backup copy */
1302                         tmp = chip->bits_per_word;
1303                         spi->bits_per_word = tmp;
1304                 }
1305         }
1306         chip->bits_per_word = tmp;
1307         u32_EDIT(chip->control, SPI_CONTROL_BITCOUNT_MASK, tmp - 1);
1308         chip->n_bytes = (tmp <= 8) ? 1 : 2;
1309
1310         /* SPI datarate */
1311         tmp = spi_data_rate(drv_data, spi->max_speed_hz);
1312         if (tmp == SPI_CONTROL_DATARATE_BAD) {
1313                 status = -EINVAL;
1314                 dev_err(&spi->dev,
1315                         "setup - "
1316                         "HW min speed (%d Hz) exceeds required "
1317                         "max speed (%d Hz)\n",
1318                         spi_speed_hz(drv_data, SPI_CONTROL_DATARATE_MIN),
1319                         spi->max_speed_hz);
1320                 if (first_setup)
1321                         goto err_first_setup;
1322                 else
1323                         /* Undo setup using chip as backup copy */
1324                         spi->max_speed_hz = chip->max_speed_hz;
1325         } else {
1326                 u32_EDIT(chip->control, SPI_CONTROL_DATARATE, tmp);
1327                 /* Actual rounded max_speed_hz */
1328                 tmp = spi_speed_hz(drv_data, tmp);
1329                 spi->max_speed_hz = tmp;
1330                 chip->max_speed_hz = tmp;
1331         }
1332
1333         /* SPI chip-select management */
1334         if (chip_info->cs_control)
1335                 chip->cs_control = chip_info->cs_control;
1336         else
1337                 chip->cs_control = null_cs_control;
1338
1339         /* Save controller_state */
1340         spi_set_ctldata(spi, chip);
1341
1342         /* Summary */
1343         dev_dbg(&spi->dev,
1344                 "setup succeded\n"
1345                 "    loopback enable   = %s\n"
1346                 "    dma enable        = %s\n"
1347                 "    insert /ss pulse  = %s\n"
1348                 "    period wait       = %d\n"
1349                 "    mode              = %d\n"
1350                 "    bits per word     = %d\n"
1351                 "    min speed         = %d Hz\n"
1352                 "    rounded max speed = %d Hz\n",
1353                 chip->test & SPI_TEST_LBC ? "Yes" : "No",
1354                 chip->enable_dma ? "Yes" : "No",
1355                 chip->control & SPI_CONTROL_SSCTL ? "Yes" : "No",
1356                 chip->period & SPI_PERIOD_WAIT,
1357                 spi->mode,
1358                 spi->bits_per_word,
1359                 spi_speed_hz(drv_data, SPI_CONTROL_DATARATE_MIN),
1360                 spi->max_speed_hz);
1361         return status;
1362
1363 err_first_setup:
1364         kfree(chip);
1365         return status;
1366 }
1367
1368 static void cleanup(struct spi_device *spi)
1369 {
1370         kfree(spi_get_ctldata(spi));
1371 }
1372
1373 static int __init init_queue(struct driver_data *drv_data)
1374 {
1375         INIT_LIST_HEAD(&drv_data->queue);
1376         spin_lock_init(&drv_data->lock);
1377
1378         drv_data->run = QUEUE_STOPPED;
1379         drv_data->busy = 0;
1380
1381         tasklet_init(&drv_data->pump_transfers,
1382                         pump_transfers, (unsigned long)drv_data);
1383
1384         INIT_WORK(&drv_data->work, pump_messages);
1385         drv_data->workqueue = create_singlethread_workqueue(
1386                                 dev_name(drv_data->master->dev.parent));
1387         if (drv_data->workqueue == NULL)
1388                 return -EBUSY;
1389
1390         return 0;
1391 }
1392
1393 static int start_queue(struct driver_data *drv_data)
1394 {
1395         unsigned long flags;
1396
1397         spin_lock_irqsave(&drv_data->lock, flags);
1398
1399         if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1400                 spin_unlock_irqrestore(&drv_data->lock, flags);
1401                 return -EBUSY;
1402         }
1403
1404         drv_data->run = QUEUE_RUNNING;
1405         drv_data->cur_msg = NULL;
1406         drv_data->cur_transfer = NULL;
1407         drv_data->cur_chip = NULL;
1408         spin_unlock_irqrestore(&drv_data->lock, flags);
1409
1410         queue_work(drv_data->workqueue, &drv_data->work);
1411
1412         return 0;
1413 }
1414
1415 static int stop_queue(struct driver_data *drv_data)
1416 {
1417         unsigned long flags;
1418         unsigned limit = 500;
1419         int status = 0;
1420
1421         spin_lock_irqsave(&drv_data->lock, flags);
1422
1423         /* This is a bit lame, but is optimized for the common execution path.
1424          * A wait_queue on the drv_data->busy could be used, but then the common
1425          * execution path (pump_messages) would be required to call wake_up or
1426          * friends on every SPI message. Do this instead */
1427         drv_data->run = QUEUE_STOPPED;
1428         while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1429                 spin_unlock_irqrestore(&drv_data->lock, flags);
1430                 msleep(10);
1431                 spin_lock_irqsave(&drv_data->lock, flags);
1432         }
1433
1434         if (!list_empty(&drv_data->queue) || drv_data->busy)
1435                 status = -EBUSY;
1436
1437         spin_unlock_irqrestore(&drv_data->lock, flags);
1438
1439         return status;
1440 }
1441
1442 static int destroy_queue(struct driver_data *drv_data)
1443 {
1444         int status;
1445
1446         status = stop_queue(drv_data);
1447         if (status != 0)
1448                 return status;
1449
1450         if (drv_data->workqueue)
1451                 destroy_workqueue(drv_data->workqueue);
1452
1453         return 0;
1454 }
1455
1456 static int __init spi_imx_probe(struct platform_device *pdev)
1457 {
1458         struct device *dev = &pdev->dev;
1459         struct spi_imx_master *platform_info;
1460         struct spi_master *master;
1461         struct driver_data *drv_data;
1462         struct resource *res;
1463         int irq, status = 0;
1464
1465         platform_info = dev->platform_data;
1466         if (platform_info == NULL) {
1467                 dev_err(&pdev->dev, "probe - no platform data supplied\n");
1468                 status = -ENODEV;
1469                 goto err_no_pdata;
1470         }
1471
1472         /* Allocate master with space for drv_data */
1473         master = spi_alloc_master(dev, sizeof(struct driver_data));
1474         if (!master) {
1475                 dev_err(&pdev->dev, "probe - cannot alloc spi_master\n");
1476                 status = -ENOMEM;
1477                 goto err_no_mem;
1478         }
1479         drv_data = spi_master_get_devdata(master);
1480         drv_data->master = master;
1481         drv_data->master_info = platform_info;
1482         drv_data->pdev = pdev;
1483
1484         master->bus_num = pdev->id;
1485         master->num_chipselect = platform_info->num_chipselect;
1486         master->dma_alignment = DMA_ALIGNMENT;
1487         master->cleanup = cleanup;
1488         master->setup = setup;
1489         master->transfer = transfer;
1490
1491         drv_data->dummy_dma_buf = SPI_DUMMY_u32;
1492
1493         drv_data->clk = clk_get(&pdev->dev, "perclk2");
1494         if (IS_ERR(drv_data->clk)) {
1495                 dev_err(&pdev->dev, "probe - cannot get clock\n");
1496                 status = PTR_ERR(drv_data->clk);
1497                 goto err_no_clk;
1498         }
1499         clk_enable(drv_data->clk);
1500
1501         /* Find and map resources */
1502         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1503         if (!res) {
1504                 dev_err(&pdev->dev, "probe - MEM resources not defined\n");
1505                 status = -ENODEV;
1506                 goto err_no_iores;
1507         }
1508         drv_data->ioarea = request_mem_region(res->start,
1509                                                 res->end - res->start + 1,
1510                                                 pdev->name);
1511         if (drv_data->ioarea == NULL) {
1512                 dev_err(&pdev->dev, "probe - cannot reserve region\n");
1513                 status = -ENXIO;
1514                 goto err_no_iores;
1515         }
1516         drv_data->regs = ioremap(res->start, res->end - res->start + 1);
1517         if (drv_data->regs == NULL) {
1518                 dev_err(&pdev->dev, "probe - cannot map IO\n");
1519                 status = -ENXIO;
1520                 goto err_no_iomap;
1521         }
1522         drv_data->rd_data_phys = (dma_addr_t)res->start;
1523
1524         /* Attach to IRQ */
1525         irq = platform_get_irq(pdev, 0);
1526         if (irq < 0) {
1527                 dev_err(&pdev->dev, "probe - IRQ resource not defined\n");
1528                 status = -ENODEV;
1529                 goto err_no_irqres;
1530         }
1531         status = request_irq(irq, spi_int, IRQF_DISABLED,
1532                              dev_name(dev), drv_data);
1533         if (status < 0) {
1534                 dev_err(&pdev->dev, "probe - cannot get IRQ (%d)\n", status);
1535                 goto err_no_irqres;
1536         }
1537
1538         /* Setup DMA if requested */
1539         drv_data->tx_channel = -1;
1540         drv_data->rx_channel = -1;
1541         if (platform_info->enable_dma) {
1542                 /* Get rx DMA channel */
1543                 drv_data->rx_channel = imx_dma_request_by_prio("spi_imx_rx",
1544                                                                DMA_PRIO_HIGH);
1545                 if (drv_data->rx_channel < 0) {
1546                         dev_err(dev,
1547                                 "probe - problem (%d) requesting rx channel\n",
1548                                 drv_data->rx_channel);
1549                         goto err_no_rxdma;
1550                 } else
1551                         imx_dma_setup_handlers(drv_data->rx_channel, NULL,
1552                                                 dma_err_handler, drv_data);
1553
1554                 /* Get tx DMA channel */
1555                 drv_data->tx_channel = imx_dma_request_by_prio("spi_imx_tx",
1556                                                                DMA_PRIO_MEDIUM);
1557                 if (drv_data->tx_channel < 0) {
1558                         dev_err(dev,
1559                                 "probe - problem (%d) requesting tx channel\n",
1560                                 drv_data->tx_channel);
1561                         imx_dma_free(drv_data->rx_channel);
1562                         goto err_no_txdma;
1563                 } else
1564                         imx_dma_setup_handlers(drv_data->tx_channel,
1565                                                 dma_tx_handler, dma_err_handler,
1566                                                 drv_data);
1567
1568                 /* Set request source and burst length for allocated channels */
1569                 switch (drv_data->pdev->id) {
1570                 case 1:
1571                         /* Using SPI1 */
1572                         RSSR(drv_data->rx_channel) = DMA_REQ_SPI1_R;
1573                         RSSR(drv_data->tx_channel) = DMA_REQ_SPI1_T;
1574                         break;
1575                 case 2:
1576                         /* Using SPI2 */
1577                         RSSR(drv_data->rx_channel) = DMA_REQ_SPI2_R;
1578                         RSSR(drv_data->tx_channel) = DMA_REQ_SPI2_T;
1579                         break;
1580                 default:
1581                         dev_err(dev, "probe - bad SPI Id\n");
1582                         imx_dma_free(drv_data->rx_channel);
1583                         imx_dma_free(drv_data->tx_channel);
1584                         status = -ENODEV;
1585                         goto err_no_devid;
1586                 }
1587                 BLR(drv_data->rx_channel) = SPI_DMA_BLR;
1588                 BLR(drv_data->tx_channel) = SPI_DMA_BLR;
1589         }
1590
1591         /* Load default SPI configuration */
1592         writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
1593         writel(0, drv_data->regs + SPI_RESET);
1594         writel(SPI_DEFAULT_CONTROL, drv_data->regs + SPI_CONTROL);
1595
1596         /* Initial and start queue */
1597         status = init_queue(drv_data);
1598         if (status != 0) {
1599                 dev_err(&pdev->dev, "probe - problem initializing queue\n");
1600                 goto err_init_queue;
1601         }
1602         status = start_queue(drv_data);
1603         if (status != 0) {
1604                 dev_err(&pdev->dev, "probe - problem starting queue\n");
1605                 goto err_start_queue;
1606         }
1607
1608         /* Register with the SPI framework */
1609         platform_set_drvdata(pdev, drv_data);
1610         status = spi_register_master(master);
1611         if (status != 0) {
1612                 dev_err(&pdev->dev, "probe - problem registering spi master\n");
1613                 goto err_spi_register;
1614         }
1615
1616         dev_dbg(dev, "probe succeded\n");
1617         return 0;
1618
1619 err_init_queue:
1620 err_start_queue:
1621 err_spi_register:
1622         destroy_queue(drv_data);
1623
1624 err_no_rxdma:
1625 err_no_txdma:
1626 err_no_devid:
1627         free_irq(irq, drv_data);
1628
1629 err_no_irqres:
1630         iounmap(drv_data->regs);
1631
1632 err_no_iomap:
1633         release_resource(drv_data->ioarea);
1634         kfree(drv_data->ioarea);
1635
1636 err_no_iores:
1637         clk_disable(drv_data->clk);
1638         clk_put(drv_data->clk);
1639
1640 err_no_clk:
1641         spi_master_put(master);
1642
1643 err_no_pdata:
1644 err_no_mem:
1645         return status;
1646 }
1647
1648 static int __exit spi_imx_remove(struct platform_device *pdev)
1649 {
1650         struct driver_data *drv_data = platform_get_drvdata(pdev);
1651         int irq;
1652         int status = 0;
1653
1654         if (!drv_data)
1655                 return 0;
1656
1657         tasklet_kill(&drv_data->pump_transfers);
1658
1659         /* Remove the queue */
1660         status = destroy_queue(drv_data);
1661         if (status != 0) {
1662                 dev_err(&pdev->dev, "queue remove failed (%d)\n", status);
1663                 return status;
1664         }
1665
1666         /* Reset SPI */
1667         writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
1668         writel(0, drv_data->regs + SPI_RESET);
1669
1670         /* Release DMA */
1671         if (drv_data->master_info->enable_dma) {
1672                 RSSR(drv_data->rx_channel) = 0;
1673                 RSSR(drv_data->tx_channel) = 0;
1674                 imx_dma_free(drv_data->tx_channel);
1675                 imx_dma_free(drv_data->rx_channel);
1676         }
1677
1678         /* Release IRQ */
1679         irq = platform_get_irq(pdev, 0);
1680         if (irq >= 0)
1681                 free_irq(irq, drv_data);
1682
1683         clk_disable(drv_data->clk);
1684         clk_put(drv_data->clk);
1685
1686         /* Release map resources */
1687         iounmap(drv_data->regs);
1688         release_resource(drv_data->ioarea);
1689         kfree(drv_data->ioarea);
1690
1691         /* Disconnect from the SPI framework */
1692         spi_unregister_master(drv_data->master);
1693         spi_master_put(drv_data->master);
1694
1695         /* Prevent double remove */
1696         platform_set_drvdata(pdev, NULL);
1697
1698         dev_dbg(&pdev->dev, "remove succeded\n");
1699
1700         return 0;
1701 }
1702
1703 static void spi_imx_shutdown(struct platform_device *pdev)
1704 {
1705         struct driver_data *drv_data = platform_get_drvdata(pdev);
1706
1707         /* Reset SPI */
1708         writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
1709         writel(0, drv_data->regs + SPI_RESET);
1710
1711         dev_dbg(&pdev->dev, "shutdown succeded\n");
1712 }
1713
1714 #ifdef CONFIG_PM
1715
1716 static int spi_imx_suspend(struct platform_device *pdev, pm_message_t state)
1717 {
1718         struct driver_data *drv_data = platform_get_drvdata(pdev);
1719         int status = 0;
1720
1721         status = stop_queue(drv_data);
1722         if (status != 0) {
1723                 dev_warn(&pdev->dev, "suspend cannot stop queue\n");
1724                 return status;
1725         }
1726
1727         dev_dbg(&pdev->dev, "suspended\n");
1728
1729         return 0;
1730 }
1731
1732 static int spi_imx_resume(struct platform_device *pdev)
1733 {
1734         struct driver_data *drv_data = platform_get_drvdata(pdev);
1735         int status = 0;
1736
1737         /* Start the queue running */
1738         status = start_queue(drv_data);
1739         if (status != 0)
1740                 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1741         else
1742                 dev_dbg(&pdev->dev, "resumed\n");
1743
1744         return status;
1745 }
1746 #else
1747 #define spi_imx_suspend NULL
1748 #define spi_imx_resume NULL
1749 #endif /* CONFIG_PM */
1750
1751 /* work with hotplug and coldplug */
1752 MODULE_ALIAS("platform:spi_imx");
1753
1754 static struct platform_driver driver = {
1755         .driver = {
1756                 .name = "spi_imx",
1757                 .owner = THIS_MODULE,
1758         },
1759         .remove = __exit_p(spi_imx_remove),
1760         .shutdown = spi_imx_shutdown,
1761         .suspend = spi_imx_suspend,
1762         .resume = spi_imx_resume,
1763 };
1764
1765 static int __init spi_imx_init(void)
1766 {
1767         return platform_driver_probe(&driver, spi_imx_probe);
1768 }
1769 module_init(spi_imx_init);
1770
1771 static void __exit spi_imx_exit(void)
1772 {
1773         platform_driver_unregister(&driver);
1774 }
1775 module_exit(spi_imx_exit);
1776
1777 MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
1778 MODULE_DESCRIPTION("iMX SPI Controller Driver");
1779 MODULE_LICENSE("GPL");