git.oblomov.eu Git - linux-2.6/blob - 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
  33 #include <asm/io.h>
  34 #include <asm/irq.h>
  35 #include <asm/hardware.h>
  36 #include <asm/delay.h>
  37
  38 #include <asm/arch/hardware.h>
  39 #include <asm/arch/imx-dma.h>
  40 #include <asm/arch/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 lenght 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 /*-------------------------------------------------------------------------*/
 190
 191
 192 /*-------------------------------------------------------------------------*/
 193 /* Driver data structs */
 194
 195 /* Context */
 196 struct driver_data {
 197         /* Driver model hookup */
 198         struct platform_device *pdev;
 199
 200         /* SPI framework hookup */
 201         struct spi_master *master;
 202
 203         /* IMX hookup */
 204         struct spi_imx_master *master_info;
 205
 206         /* Memory resources and SPI regs virtual address */
 207         struct resource *ioarea;
 208         void __iomem *regs;
 209
 210         /* SPI RX_DATA physical address */
 211         dma_addr_t rd_data_phys;
 212
 213         /* Driver message queue */
 214         struct workqueue_struct *workqueue;
 215         struct work_struct work;
 216         spinlock_t lock;
 217         struct list_head queue;
 218         int busy;
 219         int run;
 220
 221         /* Message Transfer pump */
 222         struct tasklet_struct pump_transfers;
 223
 224         /* Current message, transfer and state */
 225         struct spi_message *cur_msg;
 226         struct spi_transfer *cur_transfer;
 227         struct chip_data *cur_chip;
 228
 229         /* Rd / Wr buffers pointers */
 230         size_t len;
 231         void *tx;
 232         void *tx_end;
 233         void *rx;
 234         void *rx_end;
 235
 236         u8 rd_only;
 237         u8 n_bytes;
 238         int cs_change;
 239
 240         /* Function pointers */
 241         irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
 242         void (*cs_control)(u32 command);
 243
 244         /* DMA setup */
 245         int rx_channel;
 246         int tx_channel;
 247         dma_addr_t rx_dma;
 248         dma_addr_t tx_dma;
 249         int rx_dma_needs_unmap;
 250         int tx_dma_needs_unmap;
 251         size_t tx_map_len;
 252         u32 dummy_dma_buf ____cacheline_aligned;
 253 };
 254
 255 /* Runtime state */
 256 struct chip_data {
 257         u32 control;
 258         u32 period;
 259         u32 test;
 260
 261         u8 enable_dma:1;
 262         u8 bits_per_word;
 263         u8 n_bytes;
 264         u32 max_speed_hz;
 265
 266         void (*cs_control)(u32 command);
 267 };
 268 /*-------------------------------------------------------------------------*/
 269
 270
 271 static void pump_messages(struct work_struct *work);
 272
 273 static int flush(struct driver_data *drv_data)
 274 {
 275         unsigned long limit = loops_per_jiffy << 1;
 276         void __iomem *regs = drv_data->regs;
 277         volatile u32 d;
 278
 279         dev_dbg(&drv_data->pdev->dev, "flush\n");
 280         do {
 281                 while (readl(regs + SPI_INT_STATUS) & SPI_STATUS_RR)
 282                         d = readl(regs + SPI_RXDATA);
 283         } while ((readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH) && limit--);
 284
 285         return limit;
 286 }
 287
 288 static void restore_state(struct driver_data *drv_data)
 289 {
 290         void __iomem *regs = drv_data->regs;
 291         struct chip_data *chip = drv_data->cur_chip;
 292
 293         /* Load chip registers */
 294         dev_dbg(&drv_data->pdev->dev,
 295                 "restore_state\n"
 296                 "    test    = 0x%08X\n"
 297                 "    control = 0x%08X\n",
 298                 chip->test,
 299                 chip->control);
 300         writel(chip->test, regs + SPI_TEST);
 301         writel(chip->period, regs + SPI_PERIOD);
 302         writel(0, regs + SPI_INT_STATUS);
 303         writel(chip->control, regs + SPI_CONTROL);
 304 }
 305
 306 static void null_cs_control(u32 command)
 307 {
 308 }
 309
 310 static inline u32 data_to_write(struct driver_data *drv_data)
 311 {
 312         return ((u32)(drv_data->tx_end - drv_data->tx)) / drv_data->n_bytes;
 313 }
 314
 315 static inline u32 data_to_read(struct driver_data *drv_data)
 316 {
 317         return ((u32)(drv_data->rx_end - drv_data->rx)) / drv_data->n_bytes;
 318 }
 319
 320 static int write(struct driver_data *drv_data)
 321 {
 322         void __iomem *regs = drv_data->regs;
 323         void *tx = drv_data->tx;
 324         void *tx_end = drv_data->tx_end;
 325         u8 n_bytes = drv_data->n_bytes;
 326         u32 remaining_writes;
 327         u32 fifo_avail_space;
 328         u32 n;
 329         u16 d;
 330
 331         /* Compute how many fifo writes to do */
 332         remaining_writes = (u32)(tx_end - tx) / n_bytes;
 333         fifo_avail_space = SPI_FIFO_DEPTH -
 334                                 (readl(regs + SPI_TEST) & SPI_TEST_TXCNT);
 335         if (drv_data->rx && (fifo_avail_space > SPI_FIFO_OVERFLOW_MARGIN))
 336                 /* Fix misunderstood receive overflow */
 337                 fifo_avail_space -= SPI_FIFO_OVERFLOW_MARGIN;
 338         n = min(remaining_writes, fifo_avail_space);
 339
 340         dev_dbg(&drv_data->pdev->dev,
 341                 "write type %s\n"
 342                 "    remaining writes = %d\n"
 343                 "    fifo avail space = %d\n"
 344                 "    fifo writes      = %d\n",
 345                 (n_bytes == 1) ? "u8" : "u16",
 346                 remaining_writes,
 347                 fifo_avail_space,
 348                 n);
 349
 350         if (n > 0) {
 351                 /* Fill SPI TXFIFO */
 352                 if (drv_data->rd_only) {
 353                         tx += n * n_bytes;
 354                         while (n--)
 355                                 writel(SPI_DUMMY_u16, regs + SPI_TXDATA);
 356                 } else {
 357                         if (n_bytes == 1) {
 358                                 while (n--) {
 359                                         d = *(u8*)tx;
 360                                         writel(d, regs + SPI_TXDATA);
 361                                         tx += 1;
 362                                 }
 363                         } else {
 364                                 while (n--) {
 365                                         d = *(u16*)tx;
 366                                         writel(d, regs + SPI_TXDATA);
 367                                         tx += 2;
 368                                 }
 369                         }
 370                 }
 371
 372                 /* Trigger transfer */
 373                 writel(readl(regs + SPI_CONTROL) | SPI_CONTROL_XCH,
 374                         regs + SPI_CONTROL);
 375
 376                 /* Update tx pointer */
 377                 drv_data->tx = tx;
 378         }
 379
 380         return (tx >= tx_end);
 381 }
 382
 383 static int read(struct driver_data *drv_data)
 384 {
 385         void __iomem *regs = drv_data->regs;
 386         void *rx = drv_data->rx;
 387         void *rx_end = drv_data->rx_end;
 388         u8 n_bytes = drv_data->n_bytes;
 389         u32 remaining_reads;
 390         u32 fifo_rxcnt;
 391         u32 n;
 392         u16 d;
 393
 394         /* Compute how many fifo reads to do */
 395         remaining_reads = (u32)(rx_end - rx) / n_bytes;
 396         fifo_rxcnt = (readl(regs + SPI_TEST) & SPI_TEST_RXCNT) >>
 397                         SPI_TEST_RXCNT_LSB;
 398         n = min(remaining_reads, fifo_rxcnt);
 399
 400         dev_dbg(&drv_data->pdev->dev,
 401                 "read type %s\n"
 402                 "    remaining reads = %d\n"
 403                 "    fifo rx count   = %d\n"
 404                 "    fifo reads      = %d\n",
 405                 (n_bytes == 1) ? "u8" : "u16",
 406                 remaining_reads,
 407                 fifo_rxcnt,
 408                 n);
 409
 410         if (n > 0) {
 411                 /* Read SPI RXFIFO */
 412                 if (n_bytes == 1) {
 413                         while (n--) {
 414                                 d = readl(regs + SPI_RXDATA);
 415                                 *((u8*)rx) = d;
 416                                 rx += 1;
 417                         }
 418                 } else {
 419                         while (n--) {
 420                                 d = readl(regs + SPI_RXDATA);
 421                                 *((u16*)rx) = d;
 422                                 rx += 2;
 423                         }
 424                 }
 425
 426                 /* Update rx pointer */
 427                 drv_data->rx = rx;
 428         }
 429
 430         return (rx >= rx_end);
 431 }
 432
 433 static void *next_transfer(struct driver_data *drv_data)
 434 {
 435         struct spi_message *msg = drv_data->cur_msg;
 436         struct spi_transfer *trans = drv_data->cur_transfer;
 437
 438         /* Move to next transfer */
 439         if (trans->transfer_list.next != &msg->transfers) {
 440                 drv_data->cur_transfer =
 441                         list_entry(trans->transfer_list.next,
 442                                         struct spi_transfer,
 443                                         transfer_list);
 444                 return RUNNING_STATE;
 445         }
 446
 447         return DONE_STATE;
 448 }
 449
 450 static int map_dma_buffers(struct driver_data *drv_data)
 451 {
 452         struct spi_message *msg;
 453         struct device *dev;
 454         void *buf;
 455
 456         drv_data->rx_dma_needs_unmap = 0;
 457         drv_data->tx_dma_needs_unmap = 0;
 458
 459         if (!drv_data->master_info->enable_dma ||
 460                 !drv_data->cur_chip->enable_dma)
 461                         return -1;
 462
 463         msg = drv_data->cur_msg;
 464         dev = &msg->spi->dev;
 465         if (msg->is_dma_mapped) {
 466                 if (drv_data->tx_dma)
 467                         /* The caller provided at least dma and cpu virtual
 468                            address for write; pump_transfers() will consider the
 469                            transfer as write only if cpu rx virtual address is
 470                            NULL */
 471                         return 0;
 472
 473                 if (drv_data->rx_dma) {
 474                         /* The caller provided dma and cpu virtual address to
 475                            performe read only transfer -->
 476                            use drv_data->dummy_dma_buf for dummy writes to
 477                            achive reads */
 478                         buf = &drv_data->dummy_dma_buf;
 479                         drv_data->tx_map_len = sizeof(drv_data->dummy_dma_buf);
 480                         drv_data->tx_dma = dma_map_single(dev,
 481                                                         buf,
 482                                                         drv_data->tx_map_len,
 483                                                         DMA_TO_DEVICE);
 484                         if (dma_mapping_error(drv_data->tx_dma))
 485                                 return -1;
 486
 487                         drv_data->tx_dma_needs_unmap = 1;
 488
 489                         /* Flags transfer as rd_only for pump_transfers() DMA
 490                            regs programming (should be redundant) */
 491                         drv_data->tx = NULL;
 492
 493                         return 0;
 494                 }
 495         }
 496
 497         if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
 498                 return -1;
 499
 500         /* NULL rx means write-only transfer and no map needed
 501            since rx DMA will not be used */
 502         if (drv_data->rx) {
 503                 buf = drv_data->rx;
 504                 drv_data->rx_dma = dma_map_single(
 505                                         dev,
 506                                         buf,
 507                                         drv_data->len,
 508                                         DMA_FROM_DEVICE);
 509                 if (dma_mapping_error(drv_data->rx_dma))
 510                         return -1;
 511                 drv_data->rx_dma_needs_unmap = 1;
 512         }
 513
 514         if (drv_data->tx == NULL) {
 515                 /* Read only message --> use drv_data->dummy_dma_buf for dummy
 516                    writes to achive reads */
 517                 buf = &drv_data->dummy_dma_buf;
 518                 drv_data->tx_map_len = sizeof(drv_data->dummy_dma_buf);
 519         } else {
 520                 buf = drv_data->tx;
 521                 drv_data->tx_map_len = drv_data->len;
 522         }
 523         drv_data->tx_dma = dma_map_single(dev,
 524                                         buf,
 525                                         drv_data->tx_map_len,
 526                                         DMA_TO_DEVICE);
 527         if (dma_mapping_error(drv_data->tx_dma)) {
 528                 if (drv_data->rx_dma) {
 529                         dma_unmap_single(dev,
 530                                         drv_data->rx_dma,
 531                                         drv_data->len,
 532                                         DMA_FROM_DEVICE);
 533                         drv_data->rx_dma_needs_unmap = 0;
 534                 }
 535                 return -1;
 536         }
 537         drv_data->tx_dma_needs_unmap = 1;
 538
 539         return 0;
 540 }
 541
 542 static void unmap_dma_buffers(struct driver_data *drv_data)
 543 {
 544         struct spi_message *msg = drv_data->cur_msg;
 545         struct device *dev = &msg->spi->dev;
 546
 547         if (drv_data->rx_dma_needs_unmap) {
 548                 dma_unmap_single(dev,
 549                                 drv_data->rx_dma,
 550                                 drv_data->len,
 551                                 DMA_FROM_DEVICE);
 552                 drv_data->rx_dma_needs_unmap = 0;
 553         }
 554         if (drv_data->tx_dma_needs_unmap) {
 555                 dma_unmap_single(dev,
 556                                 drv_data->tx_dma,
 557                                 drv_data->tx_map_len,
 558                                 DMA_TO_DEVICE);
 559                 drv_data->tx_dma_needs_unmap = 0;
 560         }
 561 }
 562
 563 /* Caller already set message->status (dma is already blocked) */
 564 static void giveback(struct spi_message *message, struct driver_data *drv_data)
 565 {
 566         void __iomem *regs = drv_data->regs;
 567
 568         /* Bring SPI to sleep; restore_state() and pump_transfer()
 569            will do new setup */
 570         writel(0, regs + SPI_INT_STATUS);
 571         writel(0, regs + SPI_DMA);
 572
 573         drv_data->cs_control(SPI_CS_DEASSERT);
 574
 575         message->state = NULL;
 576         if (message->complete)
 577                 message->complete(message->context);
 578
 579         drv_data->cur_msg = NULL;
 580         drv_data->cur_transfer = NULL;
 581         drv_data->cur_chip = NULL;
 582         queue_work(drv_data->workqueue, &drv_data->work);
 583 }
 584
 585 static void dma_err_handler(int channel, void *data, int errcode)
 586 {
 587         struct driver_data *drv_data = data;
 588         struct spi_message *msg = drv_data->cur_msg;
 589
 590         dev_dbg(&drv_data->pdev->dev, "dma_err_handler\n");
 591
 592         /* Disable both rx and tx dma channels */
 593         imx_dma_disable(drv_data->rx_channel);
 594         imx_dma_disable(drv_data->tx_channel);
 595
 596         if (flush(drv_data) == 0)
 597                 dev_err(&drv_data->pdev->dev,
 598                                 "dma_err_handler - flush failed\n");
 599
 600         unmap_dma_buffers(drv_data);
 601
 602         msg->state = ERROR_STATE;
 603         tasklet_schedule(&drv_data->pump_transfers);
 604 }
 605
 606 static void dma_tx_handler(int channel, void *data)
 607 {
 608         struct driver_data *drv_data = data;
 609
 610         dev_dbg(&drv_data->pdev->dev, "dma_tx_handler\n");
 611
 612         imx_dma_disable(channel);
 613
 614         /* Now waits for TX FIFO empty */
 615         writel(readl(drv_data->regs + SPI_INT_STATUS) | SPI_INTEN_TE,
 616                         drv_data->regs + SPI_INT_STATUS);
 617 }
 618
 619 static irqreturn_t dma_transfer(struct driver_data *drv_data)
 620 {
 621         u32 status;
 622         struct spi_message *msg = drv_data->cur_msg;
 623         void __iomem *regs = drv_data->regs;
 624         unsigned long limit;
 625
 626         status = readl(regs + SPI_INT_STATUS);
 627
 628         if ((status & SPI_INTEN_RO) && (status & SPI_STATUS_RO)) {
 629                 writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
 630
 631                 imx_dma_disable(drv_data->rx_channel);
 632                 unmap_dma_buffers(drv_data);
 633
 634                 if (flush(drv_data) == 0)
 635                         dev_err(&drv_data->pdev->dev,
 636                                 "dma_transfer - flush failed\n");
 637
 638                 dev_warn(&drv_data->pdev->dev,
 639                                 "dma_transfer - fifo overun\n");
 640
 641                 msg->state = ERROR_STATE;
 642                 tasklet_schedule(&drv_data->pump_transfers);
 643
 644                 return IRQ_HANDLED;
 645         }
 646
 647         if (status & SPI_STATUS_TE) {
 648                 writel(status & ~SPI_INTEN_TE, regs + SPI_INT_STATUS);
 649
 650                 if (drv_data->rx) {
 651                         /* Wait end of transfer before read trailing data */
 652                         limit = loops_per_jiffy << 1;
 653                         while ((readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH) &&
 654                                         limit--);
 655
 656                         if (limit == 0)
 657                                 dev_err(&drv_data->pdev->dev,
 658                                         "dma_transfer - end of tx failed\n");
 659                         else
 660                                 dev_dbg(&drv_data->pdev->dev,
 661                                         "dma_transfer - end of tx\n");
 662
 663                         imx_dma_disable(drv_data->rx_channel);
 664                         unmap_dma_buffers(drv_data);
 665
 666                         /* Calculate number of trailing data and read them */
 667                         dev_dbg(&drv_data->pdev->dev,
 668                                 "dma_transfer - test = 0x%08X\n",
 669                                 readl(regs + SPI_TEST));
 670                         drv_data->rx = drv_data->rx_end -
 671                                         ((readl(regs + SPI_TEST) &
 672                                         SPI_TEST_RXCNT) >>
 673                                         SPI_TEST_RXCNT_LSB)*drv_data->n_bytes;
 674                         read(drv_data);
 675                 } else {
 676                         /* Write only transfer */
 677                         unmap_dma_buffers(drv_data);
 678
 679                         if (flush(drv_data) == 0)
 680                                 dev_err(&drv_data->pdev->dev,
 681                                         "dma_transfer - flush failed\n");
 682                 }
 683
 684                 /* End of transfer, update total byte transfered */
 685                 msg->actual_length += drv_data->len;
 686
 687                 /* Release chip select if requested, transfer delays are
 688                    handled in pump_transfers() */
 689                 if (drv_data->cs_change)
 690                         drv_data->cs_control(SPI_CS_DEASSERT);
 691
 692                 /* Move to next transfer */
 693                 msg->state = next_transfer(drv_data);
 694
 695                 /* Schedule transfer tasklet */
 696                 tasklet_schedule(&drv_data->pump_transfers);
 697
 698                 return IRQ_HANDLED;
 699         }
 700
 701         /* Opps problem detected */
 702         return IRQ_NONE;
 703 }
 704
 705 static irqreturn_t interrupt_wronly_transfer(struct driver_data *drv_data)
 706 {
 707         struct spi_message *msg = drv_data->cur_msg;
 708         void __iomem *regs = drv_data->regs;
 709         u32 status;
 710         irqreturn_t handled = IRQ_NONE;
 711
 712         status = readl(regs + SPI_INT_STATUS);
 713
 714         while (status & SPI_STATUS_TH) {
 715                 dev_dbg(&drv_data->pdev->dev,
 716                         "interrupt_wronly_transfer - status = 0x%08X\n", status);
 717
 718                 /* Pump data */
 719                 if (write(drv_data)) {
 720                         writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
 721                                 regs + SPI_INT_STATUS);
 722
 723                         dev_dbg(&drv_data->pdev->dev,
 724                                 "interrupt_wronly_transfer - end of tx\n");
 725
 726                         if (flush(drv_data) == 0)
 727                                 dev_err(&drv_data->pdev->dev,
 728                                         "interrupt_wronly_transfer - "
 729                                         "flush failed\n");
 730
 731                         /* End of transfer, update total byte transfered */
 732                         msg->actual_length += drv_data->len;
 733
 734                         /* Release chip select if requested, transfer delays are
 735                            handled in pump_transfers */
 736                         if (drv_data->cs_change)
 737                                 drv_data->cs_control(SPI_CS_DEASSERT);
 738
 739                         /* Move to next transfer */
 740                         msg->state = next_transfer(drv_data);
 741
 742                         /* Schedule transfer tasklet */
 743                         tasklet_schedule(&drv_data->pump_transfers);
 744
 745                         return IRQ_HANDLED;
 746                 }
 747
 748                 status = readl(regs + SPI_INT_STATUS);
 749
 750                 /* We did something */
 751                 handled = IRQ_HANDLED;
 752         }
 753
 754         return handled;
 755 }
 756
 757 static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 758 {
 759         struct spi_message *msg = drv_data->cur_msg;
 760         void __iomem *regs = drv_data->regs;
 761         u32 status;
 762         irqreturn_t handled = IRQ_NONE;
 763         unsigned long limit;
 764
 765         status = readl(regs + SPI_INT_STATUS);
 766
 767         while (status & (SPI_STATUS_TH | SPI_STATUS_RO)) {
 768                 dev_dbg(&drv_data->pdev->dev,
 769                         "interrupt_transfer - status = 0x%08X\n", status);
 770
 771                 if (status & SPI_STATUS_RO) {
 772                         writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
 773                                 regs + SPI_INT_STATUS);
 774
 775                         dev_warn(&drv_data->pdev->dev,
 776                                 "interrupt_transfer - fifo overun\n"
 777                                 "    data not yet written = %d\n"
 778                                 "    data not yet read    = %d\n",
 779                                 data_to_write(drv_data),
 780                                 data_to_read(drv_data));
 781
 782                         if (flush(drv_data) == 0)
 783                                 dev_err(&drv_data->pdev->dev,
 784                                         "interrupt_transfer - flush failed\n");
 785
 786                         msg->state = ERROR_STATE;
 787                         tasklet_schedule(&drv_data->pump_transfers);
 788
 789                         return IRQ_HANDLED;
 790                 }
 791
 792                 /* Pump data */
 793                 read(drv_data);
 794                 if (write(drv_data)) {
 795                         writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
 796                                 regs + SPI_INT_STATUS);
 797
 798                         dev_dbg(&drv_data->pdev->dev,
 799                                 "interrupt_transfer - end of tx\n");
 800
 801                         /* Read trailing bytes */
 802                         limit = loops_per_jiffy << 1;
 803                         while ((read(drv_data) == 0) && limit--);
 804
 805                         if (limit == 0)
 806                                 dev_err(&drv_data->pdev->dev,
 807                                         "interrupt_transfer - "
 808                                         "trailing byte read failed\n");
 809                         else
 810                                 dev_dbg(&drv_data->pdev->dev,
 811                                         "interrupt_transfer - end of rx\n");
 812
 813                         /* End of transfer, update total byte transfered */
 814                         msg->actual_length += drv_data->len;
 815
 816                         /* Release chip select if requested, transfer delays are
 817                            handled in pump_transfers */
 818                         if (drv_data->cs_change)
 819                                 drv_data->cs_control(SPI_CS_DEASSERT);
 820
 821                         /* Move to next transfer */
 822                         msg->state = next_transfer(drv_data);
 823
 824                         /* Schedule transfer tasklet */
 825                         tasklet_schedule(&drv_data->pump_transfers);
 826
 827                         return IRQ_HANDLED;
 828                 }
 829
 830                 status = readl(regs + SPI_INT_STATUS);
 831
 832                 /* We did something */
 833                 handled = IRQ_HANDLED;
 834         }
 835
 836         return handled;
 837 }
 838
 839 static irqreturn_t spi_int(int irq, void *dev_id)
 840 {
 841         struct driver_data *drv_data = (struct driver_data *)dev_id;
 842
 843         if (!drv_data->cur_msg) {
 844                 dev_err(&drv_data->pdev->dev,
 845                         "spi_int - bad message state\n");
 846                 /* Never fail */
 847                 return IRQ_HANDLED;
 848         }
 849
 850         return drv_data->transfer_handler(drv_data);
 851 }
 852
 853 static inline u32 spi_speed_hz(u32 data_rate)
 854 {
 855         return imx_get_perclk2() / (4 << ((data_rate) >> 13));
 856 }
 857
 858 static u32 spi_data_rate(u32 speed_hz)
 859 {
 860         u32 div;
 861         u32 quantized_hz = imx_get_perclk2() >> 2;
 862
 863         for (div = SPI_PERCLK2_DIV_MIN;
 864                 div <= SPI_PERCLK2_DIV_MAX;
 865                 div++, quantized_hz >>= 1) {
 866                         if (quantized_hz <= speed_hz)
 867                                 /* Max available speed LEQ required speed */
 868                                 return div << 13;
 869         }
 870         return SPI_CONTROL_DATARATE_BAD;
 871 }
 872
 873 static void pump_transfers(unsigned long data)
 874 {
 875         struct driver_data *drv_data = (struct driver_data *)data;
 876         struct spi_message *message;
 877         struct spi_transfer *transfer, *previous;
 878         struct chip_data *chip;
 879         void __iomem *regs;
 880         u32 tmp, control;
 881
 882         dev_dbg(&drv_data->pdev->dev, "pump_transfer\n");
 883
 884         message = drv_data->cur_msg;
 885
 886         /* Handle for abort */
 887         if (message->state == ERROR_STATE) {
 888                 message->status = -EIO;
 889                 giveback(message, drv_data);
 890                 return;
 891         }
 892
 893         /* Handle end of message */
 894         if (message->state == DONE_STATE) {
 895                 message->status = 0;
 896                 giveback(message, drv_data);
 897                 return;
 898         }
 899
 900         chip = drv_data->cur_chip;
 901
 902         /* Delay if requested at end of transfer*/
 903         transfer = drv_data->cur_transfer;
 904         if (message->state == RUNNING_STATE) {
 905                 previous = list_entry(transfer->transfer_list.prev,
 906                                         struct spi_transfer,
 907                                         transfer_list);
 908                 if (previous->delay_usecs)
 909                         udelay(previous->delay_usecs);
 910         } else {
 911                 /* START_STATE */
 912                 message->state = RUNNING_STATE;
 913                 drv_data->cs_control = chip->cs_control;
 914         }
 915
 916         transfer = drv_data->cur_transfer;
 917         drv_data->tx = (void *)transfer->tx_buf;
 918         drv_data->tx_end = drv_data->tx + transfer->len;
 919         drv_data->rx = transfer->rx_buf;
 920         drv_data->rx_end = drv_data->rx + transfer->len;
 921         drv_data->rx_dma = transfer->rx_dma;
 922         drv_data->tx_dma = transfer->tx_dma;
 923         drv_data->len = transfer->len;
 924         drv_data->cs_change = transfer->cs_change;
 925         drv_data->rd_only = (drv_data->tx == NULL);
 926
 927         regs = drv_data->regs;
 928         control = readl(regs + SPI_CONTROL);
 929
 930         /* Bits per word setup */
 931         tmp = transfer->bits_per_word;
 932         if (tmp == 0) {
 933                 /* Use device setup */
 934                 tmp = chip->bits_per_word;
 935                 drv_data->n_bytes = chip->n_bytes;
 936         } else
 937                 /* Use per-transfer setup */
 938                 drv_data->n_bytes = (tmp <= 8) ? 1 : 2;
 939         u32_EDIT(control, SPI_CONTROL_BITCOUNT_MASK, tmp - 1);
 940
 941         /* Speed setup (surely valid because already checked) */
 942         tmp = transfer->speed_hz;
 943         if (tmp == 0)
 944                 tmp = chip->max_speed_hz;
 945         tmp = spi_data_rate(tmp);
 946         u32_EDIT(control, SPI_CONTROL_DATARATE, tmp);
 947
 948         writel(control, regs + SPI_CONTROL);
 949
 950         /* Assert device chip-select */
 951         drv_data->cs_control(SPI_CS_ASSERT);
 952
 953         /* DMA cannot read/write SPI FIFOs other than 16 bits at a time; hence
 954            if bits_per_word is less or equal 8 PIO transfers are performed.
 955            Moreover DMA is convinient for transfer length bigger than FIFOs
 956            byte size. */
 957         if ((drv_data->n_bytes == 2) &&
 958                 (drv_data->len > SPI_FIFO_DEPTH*SPI_FIFO_BYTE_WIDTH) &&
 959                 (map_dma_buffers(drv_data) == 0)) {
 960                 dev_dbg(&drv_data->pdev->dev,
 961                         "pump dma transfer\n"
 962                         "    tx      = %p\n"
 963                         "    tx_dma  = %08X\n"
 964                         "    rx      = %p\n"
 965                         "    rx_dma  = %08X\n"
 966                         "    len     = %d\n",
 967                         drv_data->tx,
 968                         (unsigned int)drv_data->tx_dma,
 969                         drv_data->rx,
 970                         (unsigned int)drv_data->rx_dma,
 971                         drv_data->len);
 972
 973                 /* Ensure we have the correct interrupt handler */
 974                 drv_data->transfer_handler = dma_transfer;
 975
 976                 /* Trigger transfer */
 977                 writel(readl(regs + SPI_CONTROL) | SPI_CONTROL_XCH,
 978                         regs + SPI_CONTROL);
 979
 980                 /* Setup tx DMA */
 981                 if (drv_data->tx)
 982                         /* Linear source address */
 983                         CCR(drv_data->tx_channel) =
 984                                 CCR_DMOD_FIFO |
 985                                 CCR_SMOD_LINEAR |
 986                                 CCR_SSIZ_32 | CCR_DSIZ_16 |
 987                                 CCR_REN;
 988                 else
 989                         /* Read only transfer -> fixed source address for
 990                            dummy write to achive read */
 991                         CCR(drv_data->tx_channel) =
 992                                 CCR_DMOD_FIFO |
 993                                 CCR_SMOD_FIFO |
 994                                 CCR_SSIZ_32 | CCR_DSIZ_16 |
 995                                 CCR_REN;
 996
 997                 imx_dma_setup_single(
 998                         drv_data->tx_channel,
 999                         drv_data->tx_dma,
1000                         drv_data->len,
1001                         drv_data->rd_data_phys + 4,
1002                         DMA_MODE_WRITE);
1003
1004                 if (drv_data->rx) {
1005                         /* Setup rx DMA for linear destination address */
1006                         CCR(drv_data->rx_channel) =
1007                                 CCR_DMOD_LINEAR |
1008                                 CCR_SMOD_FIFO |
1009                                 CCR_DSIZ_32 | CCR_SSIZ_16 |
1010                                 CCR_REN;
1011                         imx_dma_setup_single(
1012                                 drv_data->rx_channel,
1013                                 drv_data->rx_dma,
1014                                 drv_data->len,
1015                                 drv_data->rd_data_phys,
1016                                 DMA_MODE_READ);
1017                         imx_dma_enable(drv_data->rx_channel);
1018
1019                         /* Enable SPI interrupt */
1020                         writel(SPI_INTEN_RO, regs + SPI_INT_STATUS);
1021
1022                         /* Set SPI to request DMA service on both
1023                            Rx and Tx half fifo watermark */
1024                         writel(SPI_DMA_RHDEN | SPI_DMA_THDEN, regs + SPI_DMA);
1025                 } else
1026                         /* Write only access -> set SPI to request DMA
1027                            service on Tx half fifo watermark */
1028                         writel(SPI_DMA_THDEN, regs + SPI_DMA);
1029
1030                 imx_dma_enable(drv_data->tx_channel);
1031         } else {
1032                 dev_dbg(&drv_data->pdev->dev,
1033                         "pump pio transfer\n"
1034                         "    tx      = %p\n"
1035                         "    rx      = %p\n"
1036                         "    len     = %d\n",
1037                         drv_data->tx,
1038                         drv_data->rx,
1039                         drv_data->len);
1040
1041                 /* Ensure we have the correct interrupt handler */
1042                 if (drv_data->rx)
1043                         drv_data->transfer_handler = interrupt_transfer;
1044                 else
1045                         drv_data->transfer_handler = interrupt_wronly_transfer;
1046
1047                 /* Enable SPI interrupt */
1048                 if (drv_data->rx)
1049                         writel(SPI_INTEN_TH | SPI_INTEN_RO,
1050                                 regs + SPI_INT_STATUS);
1051                 else
1052                         writel(SPI_INTEN_TH, regs + SPI_INT_STATUS);
1053         }
1054 }
1055
1056 static void pump_messages(struct work_struct *work)
1057 {
1058         struct driver_data *drv_data =
1059                                 container_of(work, struct driver_data, work);
1060         unsigned long flags;
1061
1062         /* Lock queue and check for queue work */
1063         spin_lock_irqsave(&drv_data->lock, flags);
1064         if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
1065                 drv_data->busy = 0;
1066                 spin_unlock_irqrestore(&drv_data->lock, flags);
1067                 return;
1068         }
1069
1070         /* Make sure we are not already running a message */
1071         if (drv_data->cur_msg) {
1072                 spin_unlock_irqrestore(&drv_data->lock, flags);
1073                 return;
1074         }
1075
1076         /* Extract head of queue */
1077         drv_data->cur_msg = list_entry(drv_data->queue.next,
1078                                         struct spi_message, queue);
1079         list_del_init(&drv_data->cur_msg->queue);
1080         drv_data->busy = 1;
1081         spin_unlock_irqrestore(&drv_data->lock, flags);
1082
1083         /* Initial message state */
1084         drv_data->cur_msg->state = START_STATE;
1085         drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
1086                                                 struct spi_transfer,
1087                                                 transfer_list);
1088
1089         /* Setup the SPI using the per chip configuration */
1090         drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
1091         restore_state(drv_data);
1092
1093         /* Mark as busy and launch transfers */
1094         tasklet_schedule(&drv_data->pump_transfers);
1095 }
1096
1097 static int transfer(struct spi_device *spi, struct spi_message *msg)
1098 {
1099         struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1100         u32 min_speed_hz, max_speed_hz, tmp;
1101         struct spi_transfer *trans;
1102         unsigned long flags;
1103
1104         msg->actual_length = 0;
1105
1106         /* Per transfer setup check */
1107         min_speed_hz = spi_speed_hz(SPI_CONTROL_DATARATE_MIN);
1108         max_speed_hz = spi->max_speed_hz;
1109         list_for_each_entry(trans, &msg->transfers, transfer_list) {
1110                 tmp = trans->bits_per_word;
1111                 if (tmp > 16) {
1112                         dev_err(&drv_data->pdev->dev,
1113                                 "message rejected : "
1114                                 "invalid transfer bits_per_word (%d bits)\n",
1115                                 tmp);
1116                         goto msg_rejected;
1117                 }
1118                 tmp = trans->speed_hz;
1119                 if (tmp) {
1120                         if (tmp < min_speed_hz) {
1121                                 dev_err(&drv_data->pdev->dev,
1122                                         "message rejected : "
1123                                         "device min speed (%d Hz) exceeds "
1124                                         "required transfer speed (%d Hz)\n",
1125                                         min_speed_hz,
1126                                         tmp);
1127                                 goto msg_rejected;
1128                         } else if (tmp > max_speed_hz) {
1129                                 dev_err(&drv_data->pdev->dev,
1130                                         "message rejected : "
1131                                         "transfer speed (%d Hz) exceeds "
1132                                         "device max speed (%d Hz)\n",
1133                                         tmp,
1134                                         max_speed_hz);
1135                                 goto msg_rejected;
1136                         }
1137                 }
1138         }
1139
1140         /* Message accepted */
1141         msg->status = -EINPROGRESS;
1142         msg->state = START_STATE;
1143
1144         spin_lock_irqsave(&drv_data->lock, flags);
1145         if (drv_data->run == QUEUE_STOPPED) {
1146                 spin_unlock_irqrestore(&drv_data->lock, flags);
1147                 return -ESHUTDOWN;
1148         }
1149
1150         list_add_tail(&msg->queue, &drv_data->queue);
1151         if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
1152                 queue_work(drv_data->workqueue, &drv_data->work);
1153
1154         spin_unlock_irqrestore(&drv_data->lock, flags);
1155         return 0;
1156
1157 msg_rejected:
1158         /* Message rejected and not queued */
1159         msg->status = -EINVAL;
1160         msg->state = ERROR_STATE;
1161         if (msg->complete)
1162                 msg->complete(msg->context);
1163         return -EINVAL;
1164 }
1165
1166 /* the spi->mode bits understood by this driver: */
1167 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
1168
1169 /* On first setup bad values must free chip_data memory since will cause
1170    spi_new_device to fail. Bad value setup from protocol driver are simply not
1171    applied and notified to the calling driver. */
1172 static int setup(struct spi_device *spi)
1173 {
1174         struct spi_imx_chip *chip_info;
1175         struct chip_data *chip;
1176         int first_setup = 0;
1177         u32 tmp;
1178         int status = 0;
1179
1180         if (spi->mode & ~MODEBITS) {
1181                 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
1182                         spi->mode & ~MODEBITS);
1183                 return -EINVAL;
1184         }
1185
1186         /* Get controller data */
1187         chip_info = spi->controller_data;
1188
1189         /* Get controller_state */
1190         chip = spi_get_ctldata(spi);
1191         if (chip == NULL) {
1192                 first_setup = 1;
1193
1194                 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1195                 if (!chip) {
1196                         dev_err(&spi->dev,
1197                                 "setup - cannot allocate controller state\n");
1198                         return -ENOMEM;
1199                 }
1200                 chip->control = SPI_DEFAULT_CONTROL;
1201
1202                 if (chip_info == NULL) {
1203                         /* spi_board_info.controller_data not is supplied */
1204                         chip_info = kzalloc(sizeof(struct spi_imx_chip),
1205                                                 GFP_KERNEL);
1206                         if (!chip_info) {
1207                                 dev_err(&spi->dev,
1208                                         "setup - "
1209                                         "cannot allocate controller data\n");
1210                                 status = -ENOMEM;
1211                                 goto err_first_setup;
1212                         }
1213                         /* Set controller data default value */
1214                         chip_info->enable_loopback =
1215                                                 SPI_DEFAULT_ENABLE_LOOPBACK;
1216                         chip_info->enable_dma = SPI_DEFAULT_ENABLE_DMA;
1217                         chip_info->ins_ss_pulse = 1;
1218                         chip_info->bclk_wait = SPI_DEFAULT_PERIOD_WAIT;
1219                         chip_info->cs_control = null_cs_control;
1220                 }
1221         }
1222
1223         /* Now set controller state based on controller data */
1224
1225         if (first_setup) {
1226                 /* SPI loopback */
1227                 if (chip_info->enable_loopback)
1228                         chip->test = SPI_TEST_LBC;
1229                 else
1230                         chip->test = 0;
1231
1232                 /* SPI dma driven */
1233                 chip->enable_dma = chip_info->enable_dma;
1234
1235                 /* SPI /SS pulse between spi burst */
1236                 if (chip_info->ins_ss_pulse)
1237                         u32_EDIT(chip->control,
1238                                 SPI_CONTROL_SSCTL, SPI_CONTROL_SSCTL_1);
1239                 else
1240                         u32_EDIT(chip->control,
1241                                 SPI_CONTROL_SSCTL, SPI_CONTROL_SSCTL_0);
1242
1243                 /* SPI bclk waits between each bits_per_word spi burst */
1244                 if (chip_info->bclk_wait > SPI_PERIOD_MAX_WAIT) {
1245                         dev_err(&spi->dev,
1246                                 "setup - "
1247                                 "bclk_wait exceeds max allowed (%d)\n",
1248                                 SPI_PERIOD_MAX_WAIT);
1249                         goto err_first_setup;
1250                 }
1251                 chip->period = SPI_PERIOD_CSRC_BCLK |
1252                                 (chip_info->bclk_wait & SPI_PERIOD_WAIT);
1253         }
1254
1255         /* SPI mode */
1256         tmp = spi->mode;
1257         if (tmp & SPI_CS_HIGH) {
1258                 u32_EDIT(chip->control,
1259                                 SPI_CONTROL_SSPOL, SPI_CONTROL_SSPOL_ACT_HIGH);
1260         }
1261         switch (tmp & SPI_MODE_3) {
1262         case SPI_MODE_0:
1263                 tmp = 0;
1264                 break;
1265         case SPI_MODE_1:
1266                 tmp = SPI_CONTROL_PHA_1;
1267                 break;
1268         case SPI_MODE_2:
1269                 tmp = SPI_CONTROL_POL_ACT_LOW;
1270                 break;
1271         default:
1272                 /* SPI_MODE_3 */
1273                 tmp = SPI_CONTROL_PHA_1 | SPI_CONTROL_POL_ACT_LOW;
1274                 break;
1275         }
1276         u32_EDIT(chip->control, SPI_CONTROL_POL | SPI_CONTROL_PHA, tmp);
1277
1278         /* SPI word width */
1279         tmp = spi->bits_per_word;
1280         if (tmp == 0) {
1281                 tmp = 8;
1282                 spi->bits_per_word = 8;
1283         } else if (tmp > 16) {
1284                 status = -EINVAL;
1285                 dev_err(&spi->dev,
1286                         "setup - "
1287                         "invalid bits_per_word (%d)\n",
1288                         tmp);
1289                 if (first_setup)
1290                         goto err_first_setup;
1291                 else {
1292                         /* Undo setup using chip as backup copy */
1293                         tmp = chip->bits_per_word;
1294                         spi->bits_per_word = tmp;
1295                 }
1296         }
1297         chip->bits_per_word = tmp;
1298         u32_EDIT(chip->control, SPI_CONTROL_BITCOUNT_MASK, tmp - 1);
1299         chip->n_bytes = (tmp <= 8) ? 1 : 2;
1300
1301         /* SPI datarate */
1302         tmp = spi_data_rate(spi->max_speed_hz);
1303         if (tmp == SPI_CONTROL_DATARATE_BAD) {
1304                 status = -EINVAL;
1305                 dev_err(&spi->dev,
1306                         "setup - "
1307                         "HW min speed (%d Hz) exceeds required "
1308                         "max speed (%d Hz)\n",
1309                         spi_speed_hz(SPI_CONTROL_DATARATE_MIN),
1310                         spi->max_speed_hz);
1311                 if (first_setup)
1312                         goto err_first_setup;
1313                 else
1314                         /* Undo setup using chip as backup copy */
1315                         spi->max_speed_hz = chip->max_speed_hz;
1316         } else {
1317                 u32_EDIT(chip->control, SPI_CONTROL_DATARATE, tmp);
1318                 /* Actual rounded max_speed_hz */
1319                 tmp = spi_speed_hz(tmp);
1320                 spi->max_speed_hz = tmp;
1321                 chip->max_speed_hz = tmp;
1322         }
1323
1324         /* SPI chip-select management */
1325         if (chip_info->cs_control)
1326                 chip->cs_control = chip_info->cs_control;
1327         else
1328                 chip->cs_control = null_cs_control;
1329
1330         /* Save controller_state */
1331         spi_set_ctldata(spi, chip);
1332
1333         /* Summary */
1334         dev_dbg(&spi->dev,
1335                 "setup succeded\n"
1336                 "    loopback enable   = %s\n"
1337                 "    dma enable        = %s\n"
1338                 "    insert /ss pulse  = %s\n"
1339                 "    period wait       = %d\n"
1340                 "    mode              = %d\n"
1341                 "    bits per word     = %d\n"
1342                 "    min speed         = %d Hz\n"
1343                 "    rounded max speed = %d Hz\n",
1344                 chip->test & SPI_TEST_LBC ? "Yes" : "No",
1345                 chip->enable_dma ? "Yes" : "No",
1346                 chip->control & SPI_CONTROL_SSCTL ? "Yes" : "No",
1347                 chip->period & SPI_PERIOD_WAIT,
1348                 spi->mode,
1349                 spi->bits_per_word,
1350                 spi_speed_hz(SPI_CONTROL_DATARATE_MIN),
1351                 spi->max_speed_hz);
1352         return status;
1353
1354 err_first_setup:
1355         kfree(chip);
1356         return status;
1357 }
1358
1359 static void cleanup(struct spi_device *spi)
1360 {
1361         kfree(spi_get_ctldata(spi));
1362 }
1363
1364 static int __init init_queue(struct driver_data *drv_data)
1365 {
1366         INIT_LIST_HEAD(&drv_data->queue);
1367         spin_lock_init(&drv_data->lock);
1368
1369         drv_data->run = QUEUE_STOPPED;
1370         drv_data->busy = 0;
1371
1372         tasklet_init(&drv_data->pump_transfers,
1373                         pump_transfers, (unsigned long)drv_data);
1374
1375         INIT_WORK(&drv_data->work, pump_messages);
1376         drv_data->workqueue = create_singlethread_workqueue(
1377                                         drv_data->master->dev.parent->bus_id);
1378         if (drv_data->workqueue == NULL)
1379                 return -EBUSY;
1380
1381         return 0;
1382 }
1383
1384 static int start_queue(struct driver_data *drv_data)
1385 {
1386         unsigned long flags;
1387
1388         spin_lock_irqsave(&drv_data->lock, flags);
1389
1390         if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1391                 spin_unlock_irqrestore(&drv_data->lock, flags);
1392                 return -EBUSY;
1393         }
1394
1395         drv_data->run = QUEUE_RUNNING;
1396         drv_data->cur_msg = NULL;
1397         drv_data->cur_transfer = NULL;
1398         drv_data->cur_chip = NULL;
1399         spin_unlock_irqrestore(&drv_data->lock, flags);
1400
1401         queue_work(drv_data->workqueue, &drv_data->work);
1402
1403         return 0;
1404 }
1405
1406 static int stop_queue(struct driver_data *drv_data)
1407 {
1408         unsigned long flags;
1409         unsigned limit = 500;
1410         int status = 0;
1411
1412         spin_lock_irqsave(&drv_data->lock, flags);
1413
1414         /* This is a bit lame, but is optimized for the common execution path.
1415          * A wait_queue on the drv_data->busy could be used, but then the common
1416          * execution path (pump_messages) would be required to call wake_up or
1417          * friends on every SPI message. Do this instead */
1418         drv_data->run = QUEUE_STOPPED;
1419         while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1420                 spin_unlock_irqrestore(&drv_data->lock, flags);
1421                 msleep(10);
1422                 spin_lock_irqsave(&drv_data->lock, flags);
1423         }
1424
1425         if (!list_empty(&drv_data->queue) || drv_data->busy)
1426                 status = -EBUSY;
1427
1428         spin_unlock_irqrestore(&drv_data->lock, flags);
1429
1430         return status;
1431 }
1432
1433 static int destroy_queue(struct driver_data *drv_data)
1434 {
1435         int status;
1436
1437         status = stop_queue(drv_data);
1438         if (status != 0)
1439                 return status;
1440
1441         if (drv_data->workqueue)
1442                 destroy_workqueue(drv_data->workqueue);
1443
1444         return 0;
1445 }
1446
1447 static int __init spi_imx_probe(struct platform_device *pdev)
1448 {
1449         struct device *dev = &pdev->dev;
1450         struct spi_imx_master *platform_info;
1451         struct spi_master *master;
1452         struct driver_data *drv_data = NULL;
1453         struct resource *res;
1454         int irq, status = 0;
1455
1456         platform_info = dev->platform_data;
1457         if (platform_info == NULL) {
1458                 dev_err(&pdev->dev, "probe - no platform data supplied\n");
1459                 status = -ENODEV;
1460                 goto err_no_pdata;
1461         }
1462
1463         /* Allocate master with space for drv_data */
1464         master = spi_alloc_master(dev, sizeof(struct driver_data));
1465         if (!master) {
1466                 dev_err(&pdev->dev, "probe - cannot alloc spi_master\n");
1467                 status = -ENOMEM;
1468                 goto err_no_mem;
1469         }
1470         drv_data = spi_master_get_devdata(master);
1471         drv_data->master = master;
1472         drv_data->master_info = platform_info;
1473         drv_data->pdev = pdev;
1474
1475         master->bus_num = pdev->id;
1476         master->num_chipselect = platform_info->num_chipselect;
1477         master->cleanup = cleanup;
1478         master->setup = setup;
1479         master->transfer = transfer;
1480
1481         drv_data->dummy_dma_buf = SPI_DUMMY_u32;
1482
1483         /* Find and map resources */
1484         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1485         if (!res) {
1486                 dev_err(&pdev->dev, "probe - MEM resources not defined\n");
1487                 status = -ENODEV;
1488                 goto err_no_iores;
1489         }
1490         drv_data->ioarea = request_mem_region(res->start,
1491                                                 res->end - res->start + 1,
1492                                                 pdev->name);
1493         if (drv_data->ioarea == NULL) {
1494                 dev_err(&pdev->dev, "probe - cannot reserve region\n");
1495                 status = -ENXIO;
1496                 goto err_no_iores;
1497         }
1498         drv_data->regs = ioremap(res->start, res->end - res->start + 1);
1499         if (drv_data->regs == NULL) {
1500                 dev_err(&pdev->dev, "probe - cannot map IO\n");
1501                 status = -ENXIO;
1502                 goto err_no_iomap;
1503         }
1504         drv_data->rd_data_phys = (dma_addr_t)res->start;
1505
1506         /* Attach to IRQ */
1507         irq = platform_get_irq(pdev, 0);
1508         if (irq < 0) {
1509                 dev_err(&pdev->dev, "probe - IRQ resource not defined\n");
1510                 status = -ENODEV;
1511                 goto err_no_irqres;
1512         }
1513         status = request_irq(irq, spi_int, IRQF_DISABLED, dev->bus_id, drv_data);
1514         if (status < 0) {
1515                 dev_err(&pdev->dev, "probe - cannot get IRQ (%d)\n", status);
1516                 goto err_no_irqres;
1517         }
1518
1519         /* Setup DMA if requested */
1520         drv_data->tx_channel = -1;
1521         drv_data->rx_channel = -1;
1522         if (platform_info->enable_dma) {
1523                 /* Get rx DMA channel */
1524                 status = imx_dma_request_by_prio(&drv_data->rx_channel,
1525                         "spi_imx_rx", DMA_PRIO_HIGH);
1526                 if (status < 0) {
1527                         dev_err(dev,
1528                                 "probe - problem (%d) requesting rx channel\n",
1529                                 status);
1530                         goto err_no_rxdma;
1531                 } else
1532                         imx_dma_setup_handlers(drv_data->rx_channel, NULL,
1533                                                 dma_err_handler, drv_data);
1534
1535                 /* Get tx DMA channel */
1536                 status = imx_dma_request_by_prio(&drv_data->tx_channel,
1537                                                 "spi_imx_tx", DMA_PRIO_MEDIUM);
1538                 if (status < 0) {
1539                         dev_err(dev,
1540                                 "probe - problem (%d) requesting tx channel\n",
1541                                 status);
1542                         imx_dma_free(drv_data->rx_channel);
1543                         goto err_no_txdma;
1544                 } else
1545                         imx_dma_setup_handlers(drv_data->tx_channel,
1546                                                 dma_tx_handler, dma_err_handler,
1547                                                 drv_data);
1548
1549                 /* Set request source and burst length for allocated channels */
1550                 switch (drv_data->pdev->id) {
1551                 case 1:
1552                         /* Using SPI1 */
1553                         RSSR(drv_data->rx_channel) = DMA_REQ_SPI1_R;
1554                         RSSR(drv_data->tx_channel) = DMA_REQ_SPI1_T;
1555                         break;
1556                 case 2:
1557                         /* Using SPI2 */
1558                         RSSR(drv_data->rx_channel) = DMA_REQ_SPI2_R;
1559                         RSSR(drv_data->tx_channel) = DMA_REQ_SPI2_T;
1560                         break;
1561                 default:
1562                         dev_err(dev, "probe - bad SPI Id\n");
1563                         imx_dma_free(drv_data->rx_channel);
1564                         imx_dma_free(drv_data->tx_channel);
1565                         status = -ENODEV;
1566                         goto err_no_devid;
1567                 }
1568                 BLR(drv_data->rx_channel) = SPI_DMA_BLR;
1569                 BLR(drv_data->tx_channel) = SPI_DMA_BLR;
1570         }
1571
1572         /* Load default SPI configuration */
1573         writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
1574         writel(0, drv_data->regs + SPI_RESET);
1575         writel(SPI_DEFAULT_CONTROL, drv_data->regs + SPI_CONTROL);
1576
1577         /* Initial and start queue */
1578         status = init_queue(drv_data);
1579         if (status != 0) {
1580                 dev_err(&pdev->dev, "probe - problem initializing queue\n");
1581                 goto err_init_queue;
1582         }
1583         status = start_queue(drv_data);
1584         if (status != 0) {
1585                 dev_err(&pdev->dev, "probe - problem starting queue\n");
1586                 goto err_start_queue;
1587         }
1588
1589         /* Register with the SPI framework */
1590         platform_set_drvdata(pdev, drv_data);
1591         status = spi_register_master(master);
1592         if (status != 0) {
1593                 dev_err(&pdev->dev, "probe - problem registering spi master\n");
1594                 goto err_spi_register;
1595         }
1596
1597         dev_dbg(dev, "probe succeded\n");
1598         return 0;
1599
1600 err_init_queue:
1601 err_start_queue:
1602 err_spi_register:
1603         destroy_queue(drv_data);
1604
1605 err_no_rxdma:
1606 err_no_txdma:
1607 err_no_devid:
1608         free_irq(irq, drv_data);
1609
1610 err_no_irqres:
1611         iounmap(drv_data->regs);
1612
1613 err_no_iomap:
1614         release_resource(drv_data->ioarea);
1615         kfree(drv_data->ioarea);
1616
1617 err_no_iores:
1618         spi_master_put(master);
1619
1620 err_no_pdata:
1621 err_no_mem:
1622         return status;
1623 }
1624
1625 static int __exit spi_imx_remove(struct platform_device *pdev)
1626 {
1627         struct driver_data *drv_data = platform_get_drvdata(pdev);
1628         int irq;
1629         int status = 0;
1630
1631         if (!drv_data)
1632                 return 0;
1633
1634         tasklet_kill(&drv_data->pump_transfers);
1635
1636         /* Remove the queue */
1637         status = destroy_queue(drv_data);
1638         if (status != 0) {
1639                 dev_err(&pdev->dev, "queue remove failed (%d)\n", status);
1640                 return status;
1641         }
1642
1643         /* Reset SPI */
1644         writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
1645         writel(0, drv_data->regs + SPI_RESET);
1646
1647         /* Release DMA */
1648         if (drv_data->master_info->enable_dma) {
1649                 RSSR(drv_data->rx_channel) = 0;
1650                 RSSR(drv_data->tx_channel) = 0;
1651                 imx_dma_free(drv_data->tx_channel);
1652                 imx_dma_free(drv_data->rx_channel);
1653         }
1654
1655         /* Release IRQ */
1656         irq = platform_get_irq(pdev, 0);
1657         if (irq >= 0)
1658                 free_irq(irq, drv_data);
1659
1660         /* Release map resources */
1661         iounmap(drv_data->regs);
1662         release_resource(drv_data->ioarea);
1663         kfree(drv_data->ioarea);
1664
1665         /* Disconnect from the SPI framework */
1666         spi_unregister_master(drv_data->master);
1667         spi_master_put(drv_data->master);
1668
1669         /* Prevent double remove */
1670         platform_set_drvdata(pdev, NULL);
1671
1672         dev_dbg(&pdev->dev, "remove succeded\n");
1673
1674         return 0;
1675 }
1676
1677 static void spi_imx_shutdown(struct platform_device *pdev)
1678 {
1679         struct driver_data *drv_data = platform_get_drvdata(pdev);
1680
1681         /* Reset SPI */
1682         writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
1683         writel(0, drv_data->regs + SPI_RESET);
1684
1685         dev_dbg(&pdev->dev, "shutdown succeded\n");
1686 }
1687
1688 #ifdef CONFIG_PM
1689 static int suspend_devices(struct device *dev, void *pm_message)
1690 {
1691         pm_message_t *state = pm_message;
1692
1693         if (dev->power.power_state.event != state->event) {
1694                 dev_warn(dev, "pm state does not match request\n");
1695                 return -1;
1696         }
1697
1698         return 0;
1699 }
1700
1701 static int spi_imx_suspend(struct platform_device *pdev, pm_message_t state)
1702 {
1703         struct driver_data *drv_data = platform_get_drvdata(pdev);
1704         int status = 0;
1705
1706         status = stop_queue(drv_data);
1707         if (status != 0) {
1708                 dev_warn(&pdev->dev, "suspend cannot stop queue\n");
1709                 return status;
1710         }
1711
1712         dev_dbg(&pdev->dev, "suspended\n");
1713
1714         return 0;
1715 }
1716
1717 static int spi_imx_resume(struct platform_device *pdev)
1718 {
1719         struct driver_data *drv_data = platform_get_drvdata(pdev);
1720         int status = 0;
1721
1722         /* Start the queue running */
1723         status = start_queue(drv_data);
1724         if (status != 0)
1725                 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1726         else
1727                 dev_dbg(&pdev->dev, "resumed\n");
1728
1729         return status;
1730 }
1731 #else
1732 #define spi_imx_suspend NULL
1733 #define spi_imx_resume NULL
1734 #endif /* CONFIG_PM */
1735
1736 static struct platform_driver driver = {
1737         .driver = {
1738                 .name = "spi_imx",
1739                 .bus = &platform_bus_type,
1740                 .owner = THIS_MODULE,
1741         },
1742         .remove = __exit_p(spi_imx_remove),
1743         .shutdown = spi_imx_shutdown,
1744         .suspend = spi_imx_suspend,
1745         .resume = spi_imx_resume,
1746 };
1747
1748 static int __init spi_imx_init(void)
1749 {
1750         return platform_driver_probe(&driver, spi_imx_probe);
1751 }
1752 module_init(spi_imx_init);
1753
1754 static void __exit spi_imx_exit(void)
1755 {
1756         platform_driver_unregister(&driver);
1757 }
1758 module_exit(spi_imx_exit);
1759
1760 MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
1761 MODULE_DESCRIPTION("iMX SPI Contoller Driver");
1762 MODULE_LICENSE("GPL");