drivers/spi/spi-fsl-cpm.c

   1 /*
   2  * Freescale SPI controller driver cpm functions.
   3  *
   4  * Maintainer: Kumar Gala
   5  *
   6  * Copyright (C) 2006 Polycom, Inc.
   7  * Copyright 2010 Freescale Semiconductor, Inc.
   8  *
   9  * CPM SPI and QE buffer descriptors mode support:
  10  * Copyright (c) 2009  MontaVista Software, Inc.
  11  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
  12  *
  13  * This program is free software; you can redistribute  it and/or modify it
  14  * under  the terms of  the GNU General  Public License as published by the
  15  * Free Software Foundation;  either version 2 of the  License, or (at your
  16  * option) any later version.
  17  */
  18 #include <asm/cpm.h>
  19 #include <asm/qe.h>
  20 #include <linux/dma-mapping.h>
  21 #include <linux/fsl_devices.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/of_address.h>
  25 #include <linux/spi/spi.h>
  26 #include <linux/types.h>
  27 #include <linux/platform_device.h>
  28
  29 #include "spi-fsl-cpm.h"
  30 #include "spi-fsl-lib.h"
  31 #include "spi-fsl-spi.h"
  32
  33 /* CPM1 and CPM2 are mutually exclusive. */
  34 #ifdef CONFIG_CPM1
  35 #include <asm/cpm1.h>
  36 #define CPM_SPI_CMD mk_cr_cmd(CPM_CR_CH_SPI, 0)
  37 #else
  38 #include <asm/cpm2.h>
  39 #define CPM_SPI_CMD mk_cr_cmd(CPM_CR_SPI_PAGE, CPM_CR_SPI_SBLOCK, 0, 0)
  40 #endif
  41
  42 #define SPIE_TXB        0x00000200      /* Last char is written to tx fifo */
  43 #define SPIE_RXB        0x00000100      /* Last char is written to rx buf */
  44
  45 /* SPCOM register values */
  46 #define SPCOM_STR       (1 << 23)       /* Start transmit */
  47
  48 #define SPI_PRAM_SIZE   0x100
  49 #define SPI_MRBLR       ((unsigned int)PAGE_SIZE)
  50
  51 static void *fsl_dummy_rx;
  52 static DEFINE_MUTEX(fsl_dummy_rx_lock);
  53 static int fsl_dummy_rx_refcnt;
  54
  55 void fsl_spi_cpm_reinit_txrx(struct mpc8xxx_spi *mspi)
  56 {
  57         if (mspi->flags & SPI_QE) {
  58                 qe_issue_cmd(QE_INIT_TX_RX, mspi->subblock,
  59                              QE_CR_PROTOCOL_UNSPECIFIED, 0);
  60         } else {
  61                 if (mspi->flags & SPI_CPM1) {
  62                         out_be32(&mspi->pram->rstate, 0);
  63                         out_be16(&mspi->pram->rbptr,
  64                                  in_be16(&mspi->pram->rbase));
  65                         out_be32(&mspi->pram->tstate, 0);
  66                         out_be16(&mspi->pram->tbptr,
  67                                  in_be16(&mspi->pram->tbase));
  68                 } else {
  69                         cpm_command(CPM_SPI_CMD, CPM_CR_INIT_TRX);
  70                 }
  71         }
  72 }
  73 EXPORT_SYMBOL_GPL(fsl_spi_cpm_reinit_txrx);
  74
  75 static void fsl_spi_cpm_bufs_start(struct mpc8xxx_spi *mspi)
  76 {
  77         struct cpm_buf_desc __iomem *tx_bd = mspi->tx_bd;
  78         struct cpm_buf_desc __iomem *rx_bd = mspi->rx_bd;
  79         unsigned int xfer_len = min(mspi->count, SPI_MRBLR);
  80         unsigned int xfer_ofs;
  81         struct fsl_spi_reg *reg_base = mspi->reg_base;
  82
  83         xfer_ofs = mspi->xfer_in_progress->len - mspi->count;
  84
  85         if (mspi->rx_dma == mspi->dma_dummy_rx)
  86                 out_be32(&rx_bd->cbd_bufaddr, mspi->rx_dma);
  87         else
  88                 out_be32(&rx_bd->cbd_bufaddr, mspi->rx_dma + xfer_ofs);
  89         out_be16(&rx_bd->cbd_datlen, 0);
  90         out_be16(&rx_bd->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT | BD_SC_WRAP);
  91
  92         if (mspi->tx_dma == mspi->dma_dummy_tx)
  93                 out_be32(&tx_bd->cbd_bufaddr, mspi->tx_dma);
  94         else
  95                 out_be32(&tx_bd->cbd_bufaddr, mspi->tx_dma + xfer_ofs);
  96         out_be16(&tx_bd->cbd_datlen, xfer_len);
  97         out_be16(&tx_bd->cbd_sc, BD_SC_READY | BD_SC_INTRPT | BD_SC_WRAP |
  98                                  BD_SC_LAST);
  99
 100         /* start transfer */
 101         mpc8xxx_spi_write_reg(&reg_base->command, SPCOM_STR);
 102 }
 103
 104 int fsl_spi_cpm_bufs(struct mpc8xxx_spi *mspi,
 105                      struct spi_transfer *t, bool is_dma_mapped)
 106 {
 107         struct device *dev = mspi->dev;
 108         struct fsl_spi_reg *reg_base = mspi->reg_base;
 109
 110         if (is_dma_mapped) {
 111                 mspi->map_tx_dma = 0;
 112                 mspi->map_rx_dma = 0;
 113         } else {
 114                 mspi->map_tx_dma = 1;
 115                 mspi->map_rx_dma = 1;
 116         }
 117
 118         if (!t->tx_buf) {
 119                 mspi->tx_dma = mspi->dma_dummy_tx;
 120                 mspi->map_tx_dma = 0;
 121         }
 122
 123         if (!t->rx_buf) {
 124                 mspi->rx_dma = mspi->dma_dummy_rx;
 125                 mspi->map_rx_dma = 0;
 126         }
 127
 128         if (mspi->map_tx_dma) {
 129                 void *nonconst_tx = (void *)mspi->tx; /* shut up gcc */
 130
 131                 mspi->tx_dma = dma_map_single(dev, nonconst_tx, t->len,
 132                                               DMA_TO_DEVICE);
 133                 if (dma_mapping_error(dev, mspi->tx_dma)) {
 134                         dev_err(dev, "unable to map tx dma\n");
 135                         return -ENOMEM;
 136                 }
 137         } else if (t->tx_buf) {
 138                 mspi->tx_dma = t->tx_dma;
 139         }
 140
 141         if (mspi->map_rx_dma) {
 142                 mspi->rx_dma = dma_map_single(dev, mspi->rx, t->len,
 143                                               DMA_FROM_DEVICE);
 144                 if (dma_mapping_error(dev, mspi->rx_dma)) {
 145                         dev_err(dev, "unable to map rx dma\n");
 146                         goto err_rx_dma;
 147                 }
 148         } else if (t->rx_buf) {
 149                 mspi->rx_dma = t->rx_dma;
 150         }
 151
 152         /* enable rx ints */
 153         mpc8xxx_spi_write_reg(&reg_base->mask, SPIE_RXB);
 154
 155         mspi->xfer_in_progress = t;
 156         mspi->count = t->len;
 157
 158         /* start CPM transfers */
 159         fsl_spi_cpm_bufs_start(mspi);
 160
 161         return 0;
 162
 163 err_rx_dma:
 164         if (mspi->map_tx_dma)
 165                 dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
 166         return -ENOMEM;
 167 }
 168 EXPORT_SYMBOL_GPL(fsl_spi_cpm_bufs);
 169
 170 void fsl_spi_cpm_bufs_complete(struct mpc8xxx_spi *mspi)
 171 {
 172         struct device *dev = mspi->dev;
 173         struct spi_transfer *t = mspi->xfer_in_progress;
 174
 175         if (mspi->map_tx_dma)
 176                 dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
 177         if (mspi->map_rx_dma)
 178                 dma_unmap_single(dev, mspi->rx_dma, t->len, DMA_FROM_DEVICE);
 179         mspi->xfer_in_progress = NULL;
 180 }
 181 EXPORT_SYMBOL_GPL(fsl_spi_cpm_bufs_complete);
 182
 183 void fsl_spi_cpm_irq(struct mpc8xxx_spi *mspi, u32 events)
 184 {
 185         u16 len;
 186         struct fsl_spi_reg *reg_base = mspi->reg_base;
 187
 188         dev_dbg(mspi->dev, "%s: bd datlen %d, count %d\n", __func__,
 189                 in_be16(&mspi->rx_bd->cbd_datlen), mspi->count);
 190
 191         len = in_be16(&mspi->rx_bd->cbd_datlen);
 192         if (len > mspi->count) {
 193                 WARN_ON(1);
 194                 len = mspi->count;
 195         }
 196
 197         /* Clear the events */
 198         mpc8xxx_spi_write_reg(&reg_base->event, events);
 199
 200         mspi->count -= len;
 201         if (mspi->count)
 202                 fsl_spi_cpm_bufs_start(mspi);
 203         else
 204                 complete(&mspi->done);
 205 }
 206 EXPORT_SYMBOL_GPL(fsl_spi_cpm_irq);
 207
 208 static void *fsl_spi_alloc_dummy_rx(void)
 209 {
 210         mutex_lock(&fsl_dummy_rx_lock);
 211
 212         if (!fsl_dummy_rx)
 213                 fsl_dummy_rx = kmalloc(SPI_MRBLR, GFP_KERNEL);
 214         if (fsl_dummy_rx)
 215                 fsl_dummy_rx_refcnt++;
 216
 217         mutex_unlock(&fsl_dummy_rx_lock);
 218
 219         return fsl_dummy_rx;
 220 }
 221
 222 static void fsl_spi_free_dummy_rx(void)
 223 {
 224         mutex_lock(&fsl_dummy_rx_lock);
 225
 226         switch (fsl_dummy_rx_refcnt) {
 227         case 0:
 228                 WARN_ON(1);
 229                 break;
 230         case 1:
 231                 kfree(fsl_dummy_rx);
 232                 fsl_dummy_rx = NULL;
 233                 /* fall through */
 234         default:
 235                 fsl_dummy_rx_refcnt--;
 236                 break;
 237         }
 238
 239         mutex_unlock(&fsl_dummy_rx_lock);
 240 }
 241
 242 static unsigned long fsl_spi_cpm_get_pram(struct mpc8xxx_spi *mspi)
 243 {
 244         struct device *dev = mspi->dev;
 245         struct device_node *np = dev->of_node;
 246         const u32 *iprop;
 247         int size;
 248         void __iomem *spi_base;
 249         unsigned long pram_ofs = -ENOMEM;
 250
 251         /* Can't use of_address_to_resource(), QE muram isn't at 0. */
 252         iprop = of_get_property(np, "reg", &size);
 253
 254         /* QE with a fixed pram location? */
 255         if (mspi->flags & SPI_QE && iprop && size == sizeof(*iprop) * 4)
 256                 return cpm_muram_alloc_fixed(iprop[2], SPI_PRAM_SIZE);
 257
 258         /* QE but with a dynamic pram location? */
 259         if (mspi->flags & SPI_QE) {
 260                 pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
 261                 qe_issue_cmd(QE_ASSIGN_PAGE_TO_DEVICE, mspi->subblock,
 262                              QE_CR_PROTOCOL_UNSPECIFIED, pram_ofs);
 263                 return pram_ofs;
 264         }
 265
 266         spi_base = of_iomap(np, 1);
 267         if (spi_base == NULL)
 268                 return -EINVAL;
 269
 270         if (mspi->flags & SPI_CPM2) {
 271                 pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
 272                 out_be16(spi_base, pram_ofs);
 273         }
 274
 275         iounmap(spi_base);
 276         return pram_ofs;
 277 }
 278
 279 int fsl_spi_cpm_init(struct mpc8xxx_spi *mspi)
 280 {
 281         struct device *dev = mspi->dev;
 282         struct device_node *np = dev->of_node;
 283         const u32 *iprop;
 284         int size;
 285         unsigned long bds_ofs;
 286
 287         if (!(mspi->flags & SPI_CPM_MODE))
 288                 return 0;
 289
 290         if (!fsl_spi_alloc_dummy_rx())
 291                 return -ENOMEM;
 292
 293         if (mspi->flags & SPI_QE) {
 294                 iprop = of_get_property(np, "cell-index", &size);
 295                 if (iprop && size == sizeof(*iprop))
 296                         mspi->subblock = *iprop;
 297
 298                 switch (mspi->subblock) {
 299                 default:
 300                         dev_warn(dev, "cell-index unspecified, assuming SPI1\n");
 301                         /* fall through */
 302                 case 0:
 303                         mspi->subblock = QE_CR_SUBBLOCK_SPI1;
 304                         break;
 305                 case 1:
 306                         mspi->subblock = QE_CR_SUBBLOCK_SPI2;
 307                         break;
 308                 }
 309         }
 310
 311         if (mspi->flags & SPI_CPM1) {
 312                 struct resource *res;
 313                 void *pram;
 314
 315                 res = platform_get_resource(to_platform_device(dev),
 316                                             IORESOURCE_MEM, 1);
 317                 pram = devm_ioremap_resource(dev, res);
 318                 if (IS_ERR(pram))
 319                         mspi->pram = NULL;
 320                 else
 321                         mspi->pram = pram;
 322         } else {
 323                 unsigned long pram_ofs = fsl_spi_cpm_get_pram(mspi);
 324
 325                 if (IS_ERR_VALUE(pram_ofs))
 326                         mspi->pram = NULL;
 327                 else
 328                         mspi->pram = cpm_muram_addr(pram_ofs);
 329         }
 330         if (mspi->pram == NULL) {
 331                 dev_err(dev, "can't allocate spi parameter ram\n");
 332                 goto err_pram;
 333         }
 334
 335         bds_ofs = cpm_muram_alloc(sizeof(*mspi->tx_bd) +
 336                                   sizeof(*mspi->rx_bd), 8);
 337         if (IS_ERR_VALUE(bds_ofs)) {
 338                 dev_err(dev, "can't allocate bds\n");
 339                 goto err_bds;
 340         }
 341
 342         mspi->dma_dummy_tx = dma_map_single(dev, empty_zero_page, PAGE_SIZE,
 343                                             DMA_TO_DEVICE);
 344         if (dma_mapping_error(dev, mspi->dma_dummy_tx)) {
 345                 dev_err(dev, "unable to map dummy tx buffer\n");
 346                 goto err_dummy_tx;
 347         }
 348
 349         mspi->dma_dummy_rx = dma_map_single(dev, fsl_dummy_rx, SPI_MRBLR,
 350                                             DMA_FROM_DEVICE);
 351         if (dma_mapping_error(dev, mspi->dma_dummy_rx)) {
 352                 dev_err(dev, "unable to map dummy rx buffer\n");
 353                 goto err_dummy_rx;
 354         }
 355
 356         mspi->tx_bd = cpm_muram_addr(bds_ofs);
 357         mspi->rx_bd = cpm_muram_addr(bds_ofs + sizeof(*mspi->tx_bd));
 358
 359         /* Initialize parameter ram. */
 360         out_be16(&mspi->pram->tbase, cpm_muram_offset(mspi->tx_bd));
 361         out_be16(&mspi->pram->rbase, cpm_muram_offset(mspi->rx_bd));
 362         out_8(&mspi->pram->tfcr, CPMFCR_EB | CPMFCR_GBL);
 363         out_8(&mspi->pram->rfcr, CPMFCR_EB | CPMFCR_GBL);
 364         out_be16(&mspi->pram->mrblr, SPI_MRBLR);
 365         out_be32(&mspi->pram->rstate, 0);
 366         out_be32(&mspi->pram->rdp, 0);
 367         out_be16(&mspi->pram->rbptr, 0);
 368         out_be16(&mspi->pram->rbc, 0);
 369         out_be32(&mspi->pram->rxtmp, 0);
 370         out_be32(&mspi->pram->tstate, 0);
 371         out_be32(&mspi->pram->tdp, 0);
 372         out_be16(&mspi->pram->tbptr, 0);
 373         out_be16(&mspi->pram->tbc, 0);
 374         out_be32(&mspi->pram->txtmp, 0);
 375
 376         return 0;
 377
 378 err_dummy_rx:
 379         dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
 380 err_dummy_tx:
 381         cpm_muram_free(bds_ofs);
 382 err_bds:
 383         if (!(mspi->flags & SPI_CPM1))
 384                 cpm_muram_free(cpm_muram_offset(mspi->pram));
 385 err_pram:
 386         fsl_spi_free_dummy_rx();
 387         return -ENOMEM;
 388 }
 389 EXPORT_SYMBOL_GPL(fsl_spi_cpm_init);
 390
 391 void fsl_spi_cpm_free(struct mpc8xxx_spi *mspi)
 392 {
 393         struct device *dev = mspi->dev;
 394
 395         if (!(mspi->flags & SPI_CPM_MODE))
 396                 return;
 397
 398         dma_unmap_single(dev, mspi->dma_dummy_rx, SPI_MRBLR, DMA_FROM_DEVICE);
 399         dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
 400         cpm_muram_free(cpm_muram_offset(mspi->tx_bd));
 401         cpm_muram_free(cpm_muram_offset(mspi->pram));
 402         fsl_spi_free_dummy_rx();
 403 }
 404 EXPORT_SYMBOL_GPL(fsl_spi_cpm_free);
 405
 406 MODULE_LICENSE("GPL");