drivers/spi/spi-fsl-cpm.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Freescale SPI controller driver cpm functions.
   4  *
   5  * Maintainer: Kumar Gala
   6  *
   7  * Copyright (C) 2006 Polycom, Inc.
   8  * Copyright 2010 Freescale Semiconductor, Inc.
   9  *
  10  * CPM SPI and QE buffer descriptors mode support:
  11  * Copyright (c) 2009  MontaVista Software, Inc.
  12  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
  13  */
  14 #include <asm/cpm.h>
  15 #include <soc/fsl/qe/qe.h>
  16 #include <linux/dma-mapping.h>
  17 #include <linux/fsl_devices.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/of_address.h>
  21 #include <linux/spi/spi.h>
  22 #include <linux/types.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/byteorder/generic.h>
  25
  26 #include "spi-fsl-cpm.h"
  27 #include "spi-fsl-lib.h"
  28 #include "spi-fsl-spi.h"
  29
  30 /* CPM1 and CPM2 are mutually exclusive. */
  31 #ifdef CONFIG_CPM1
  32 #include <asm/cpm1.h>
  33 #define CPM_SPI_CMD mk_cr_cmd(CPM_CR_CH_SPI, 0)
  34 #else
  35 #include <asm/cpm2.h>
  36 #define CPM_SPI_CMD mk_cr_cmd(CPM_CR_SPI_PAGE, CPM_CR_SPI_SBLOCK, 0, 0)
  37 #endif
  38
  39 #define SPIE_TXB        0x00000200      /* Last char is written to tx fifo */
  40 #define SPIE_RXB        0x00000100      /* Last char is written to rx buf */
  41
  42 /* SPCOM register values */
  43 #define SPCOM_STR       (1 << 23)       /* Start transmit */
  44
  45 #define SPI_PRAM_SIZE   0x100
  46 #define SPI_MRBLR       ((unsigned int)PAGE_SIZE)
  47
  48 static void *fsl_dummy_rx;
  49 static DEFINE_MUTEX(fsl_dummy_rx_lock);
  50 static int fsl_dummy_rx_refcnt;
  51
  52 void fsl_spi_cpm_reinit_txrx(struct mpc8xxx_spi *mspi)
  53 {
  54         if (mspi->flags & SPI_QE) {
  55                 qe_issue_cmd(QE_INIT_TX_RX, mspi->subblock,
  56                              QE_CR_PROTOCOL_UNSPECIFIED, 0);
  57         } else {
  58                 if (mspi->flags & SPI_CPM1) {
  59                         iowrite32be(0, &mspi->pram->rstate);
  60                         iowrite16be(ioread16be(&mspi->pram->rbase),
  61                                     &mspi->pram->rbptr);
  62                         iowrite32be(0, &mspi->pram->tstate);
  63                         iowrite16be(ioread16be(&mspi->pram->tbase),
  64                                     &mspi->pram->tbptr);
  65                 } else {
  66                         cpm_command(CPM_SPI_CMD, CPM_CR_INIT_TRX);
  67                 }
  68         }
  69 }
  70 EXPORT_SYMBOL_GPL(fsl_spi_cpm_reinit_txrx);
  71
  72 static void fsl_spi_cpm_bufs_start(struct mpc8xxx_spi *mspi)
  73 {
  74         struct cpm_buf_desc __iomem *tx_bd = mspi->tx_bd;
  75         struct cpm_buf_desc __iomem *rx_bd = mspi->rx_bd;
  76         unsigned int xfer_len = min(mspi->count, SPI_MRBLR);
  77         unsigned int xfer_ofs;
  78         struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
  79
  80         xfer_ofs = mspi->xfer_in_progress->len - mspi->count;
  81
  82         if (mspi->rx_dma == mspi->dma_dummy_rx)
  83                 iowrite32be(mspi->rx_dma, &rx_bd->cbd_bufaddr);
  84         else
  85                 iowrite32be(mspi->rx_dma + xfer_ofs, &rx_bd->cbd_bufaddr);
  86         iowrite16be(0, &rx_bd->cbd_datlen);
  87         iowrite16be(BD_SC_EMPTY | BD_SC_INTRPT | BD_SC_WRAP, &rx_bd->cbd_sc);
  88
  89         if (mspi->tx_dma == mspi->dma_dummy_tx)
  90                 iowrite32be(mspi->tx_dma, &tx_bd->cbd_bufaddr);
  91         else
  92                 iowrite32be(mspi->tx_dma + xfer_ofs, &tx_bd->cbd_bufaddr);
  93         iowrite16be(xfer_len, &tx_bd->cbd_datlen);
  94         iowrite16be(BD_SC_READY | BD_SC_INTRPT | BD_SC_WRAP | BD_SC_LAST,
  95                     &tx_bd->cbd_sc);
  96
  97         /* start transfer */
  98         mpc8xxx_spi_write_reg(&reg_base->command, SPCOM_STR);
  99 }
 100
 101 int fsl_spi_cpm_bufs(struct mpc8xxx_spi *mspi, struct spi_transfer *t)
 102 {
 103         struct device *dev = mspi->dev;
 104         struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
 105
 106         mspi->map_tx_dma = 1;
 107         mspi->map_rx_dma = 1;
 108
 109         if (!t->tx_buf) {
 110                 mspi->tx_dma = mspi->dma_dummy_tx;
 111                 mspi->map_tx_dma = 0;
 112         }
 113
 114         if (!t->rx_buf) {
 115                 mspi->rx_dma = mspi->dma_dummy_rx;
 116                 mspi->map_rx_dma = 0;
 117         }
 118         if (t->bits_per_word == 16 && t->tx_buf) {
 119                 const u16 *src = t->tx_buf;
 120                 __le16 *dst;
 121                 int i;
 122
 123                 dst = kmalloc(t->len, GFP_KERNEL);
 124                 if (!dst)
 125                         return -ENOMEM;
 126
 127                 for (i = 0; i < t->len >> 1; i++)
 128                         dst[i] = cpu_to_le16p(src + i);
 129
 130                 mspi->tx = dst;
 131                 mspi->map_tx_dma = 1;
 132         }
 133
 134         if (mspi->map_tx_dma) {
 135                 void *nonconst_tx = (void *)mspi->tx; /* shut up gcc */
 136
 137                 mspi->tx_dma = dma_map_single(dev, nonconst_tx, t->len,
 138                                               DMA_TO_DEVICE);
 139                 if (dma_mapping_error(dev, mspi->tx_dma)) {
 140                         dev_err(dev, "unable to map tx dma\n");
 141                         return -ENOMEM;
 142                 }
 143         } else if (t->tx_buf) {
 144                 mspi->tx_dma = 0;
 145         }
 146
 147         if (mspi->map_rx_dma) {
 148                 mspi->rx_dma = dma_map_single(dev, mspi->rx, t->len,
 149                                               DMA_FROM_DEVICE);
 150                 if (dma_mapping_error(dev, mspi->rx_dma)) {
 151                         dev_err(dev, "unable to map rx dma\n");
 152                         goto err_rx_dma;
 153                 }
 154         } else if (t->rx_buf) {
 155                 mspi->rx_dma = t->rx_dma;
 156         }
 157
 158         /* enable rx ints */
 159         mpc8xxx_spi_write_reg(&reg_base->mask, SPIE_RXB);
 160
 161         mspi->xfer_in_progress = t;
 162         mspi->count = t->len;
 163
 164         /* start CPM transfers */
 165         fsl_spi_cpm_bufs_start(mspi);
 166
 167         return 0;
 168
 169 err_rx_dma:
 170         if (mspi->map_tx_dma)
 171                 dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
 172         return -ENOMEM;
 173 }
 174 EXPORT_SYMBOL_GPL(fsl_spi_cpm_bufs);
 175
 176 void fsl_spi_cpm_bufs_complete(struct mpc8xxx_spi *mspi)
 177 {
 178         struct device *dev = mspi->dev;
 179         struct spi_transfer *t = mspi->xfer_in_progress;
 180
 181         if (mspi->map_tx_dma)
 182                 dma_unmap_single(dev, mspi->tx_dma, t->len, DMA_TO_DEVICE);
 183         if (mspi->map_rx_dma)
 184                 dma_unmap_single(dev, mspi->rx_dma, t->len, DMA_FROM_DEVICE);
 185         mspi->xfer_in_progress = NULL;
 186
 187         if (t->bits_per_word == 16 && t->rx_buf) {
 188                 int i;
 189
 190                 for (i = 0; i < t->len; i += 2)
 191                         le16_to_cpus(t->rx_buf + i);
 192         }
 193 }
 194 EXPORT_SYMBOL_GPL(fsl_spi_cpm_bufs_complete);
 195
 196 void fsl_spi_cpm_irq(struct mpc8xxx_spi *mspi, u32 events)
 197 {
 198         u16 len;
 199         struct fsl_spi_reg __iomem *reg_base = mspi->reg_base;
 200
 201         dev_dbg(mspi->dev, "%s: bd datlen %d, count %d\n", __func__,
 202                 ioread16be(&mspi->rx_bd->cbd_datlen), mspi->count);
 203
 204         len = ioread16be(&mspi->rx_bd->cbd_datlen);
 205         if (len > mspi->count) {
 206                 WARN_ON(1);
 207                 len = mspi->count;
 208         }
 209
 210         /* Clear the events */
 211         mpc8xxx_spi_write_reg(&reg_base->event, events);
 212
 213         mspi->count -= len;
 214         if (mspi->count)
 215                 fsl_spi_cpm_bufs_start(mspi);
 216         else
 217                 complete(&mspi->done);
 218 }
 219 EXPORT_SYMBOL_GPL(fsl_spi_cpm_irq);
 220
 221 static void *fsl_spi_alloc_dummy_rx(void)
 222 {
 223         mutex_lock(&fsl_dummy_rx_lock);
 224
 225         if (!fsl_dummy_rx)
 226                 fsl_dummy_rx = kmalloc(SPI_MRBLR, GFP_KERNEL);
 227         if (fsl_dummy_rx)
 228                 fsl_dummy_rx_refcnt++;
 229
 230         mutex_unlock(&fsl_dummy_rx_lock);
 231
 232         return fsl_dummy_rx;
 233 }
 234
 235 static void fsl_spi_free_dummy_rx(void)
 236 {
 237         mutex_lock(&fsl_dummy_rx_lock);
 238
 239         switch (fsl_dummy_rx_refcnt) {
 240         case 0:
 241                 WARN_ON(1);
 242                 break;
 243         case 1:
 244                 kfree(fsl_dummy_rx);
 245                 fsl_dummy_rx = NULL;
 246                 fallthrough;
 247         default:
 248                 fsl_dummy_rx_refcnt--;
 249                 break;
 250         }
 251
 252         mutex_unlock(&fsl_dummy_rx_lock);
 253 }
 254
 255 static unsigned long fsl_spi_cpm_get_pram(struct mpc8xxx_spi *mspi)
 256 {
 257         struct device *dev = mspi->dev;
 258         struct device_node *np = dev->of_node;
 259         const u32 *iprop;
 260         int size;
 261         void __iomem *spi_base;
 262         unsigned long pram_ofs = -ENOMEM;
 263
 264         /* Can't use of_address_to_resource(), QE muram isn't at 0. */
 265         iprop = of_get_property(np, "reg", &size);
 266
 267         /* QE with a fixed pram location? */
 268         if (mspi->flags & SPI_QE && iprop && size == sizeof(*iprop) * 4)
 269                 return cpm_muram_alloc_fixed(iprop[2], SPI_PRAM_SIZE);
 270
 271         /* QE but with a dynamic pram location? */
 272         if (mspi->flags & SPI_QE) {
 273                 pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
 274                 qe_issue_cmd(QE_ASSIGN_PAGE_TO_DEVICE, mspi->subblock,
 275                              QE_CR_PROTOCOL_UNSPECIFIED, pram_ofs);
 276                 return pram_ofs;
 277         }
 278
 279         spi_base = of_iomap(np, 1);
 280         if (spi_base == NULL)
 281                 return -EINVAL;
 282
 283         if (mspi->flags & SPI_CPM2) {
 284                 pram_ofs = cpm_muram_alloc(SPI_PRAM_SIZE, 64);
 285                 out_be16(spi_base, pram_ofs);
 286         }
 287
 288         iounmap(spi_base);
 289         return pram_ofs;
 290 }
 291
 292 int fsl_spi_cpm_init(struct mpc8xxx_spi *mspi)
 293 {
 294         struct device *dev = mspi->dev;
 295         struct device_node *np = dev->of_node;
 296         const u32 *iprop;
 297         int size;
 298         unsigned long bds_ofs;
 299
 300         if (!(mspi->flags & SPI_CPM_MODE))
 301                 return 0;
 302
 303         if (!fsl_spi_alloc_dummy_rx())
 304                 return -ENOMEM;
 305
 306         if (mspi->flags & SPI_QE) {
 307                 iprop = of_get_property(np, "cell-index", &size);
 308                 if (iprop && size == sizeof(*iprop))
 309                         mspi->subblock = *iprop;
 310
 311                 switch (mspi->subblock) {
 312                 default:
 313                         dev_warn(dev, "cell-index unspecified, assuming SPI1\n");
 314                         fallthrough;
 315                 case 0:
 316                         mspi->subblock = QE_CR_SUBBLOCK_SPI1;
 317                         break;
 318                 case 1:
 319                         mspi->subblock = QE_CR_SUBBLOCK_SPI2;
 320                         break;
 321                 }
 322         }
 323
 324         if (mspi->flags & SPI_CPM1) {
 325                 void __iomem *pram;
 326
 327                 pram = devm_platform_ioremap_resource(to_platform_device(dev),
 328                                                       1);
 329                 if (IS_ERR(pram))
 330                         mspi->pram = NULL;
 331                 else
 332                         mspi->pram = pram;
 333         } else {
 334                 unsigned long pram_ofs = fsl_spi_cpm_get_pram(mspi);
 335
 336                 if (IS_ERR_VALUE(pram_ofs))
 337                         mspi->pram = NULL;
 338                 else
 339                         mspi->pram = cpm_muram_addr(pram_ofs);
 340         }
 341         if (mspi->pram == NULL) {
 342                 dev_err(dev, "can't allocate spi parameter ram\n");
 343                 goto err_pram;
 344         }
 345
 346         bds_ofs = cpm_muram_alloc(sizeof(*mspi->tx_bd) +
 347                                   sizeof(*mspi->rx_bd), 8);
 348         if (IS_ERR_VALUE(bds_ofs)) {
 349                 dev_err(dev, "can't allocate bds\n");
 350                 goto err_bds;
 351         }
 352
 353         mspi->dma_dummy_tx = dma_map_single(dev, ZERO_PAGE(0), PAGE_SIZE,
 354                                             DMA_TO_DEVICE);
 355         if (dma_mapping_error(dev, mspi->dma_dummy_tx)) {
 356                 dev_err(dev, "unable to map dummy tx buffer\n");
 357                 goto err_dummy_tx;
 358         }
 359
 360         mspi->dma_dummy_rx = dma_map_single(dev, fsl_dummy_rx, SPI_MRBLR,
 361                                             DMA_FROM_DEVICE);
 362         if (dma_mapping_error(dev, mspi->dma_dummy_rx)) {
 363                 dev_err(dev, "unable to map dummy rx buffer\n");
 364                 goto err_dummy_rx;
 365         }
 366
 367         mspi->tx_bd = cpm_muram_addr(bds_ofs);
 368         mspi->rx_bd = cpm_muram_addr(bds_ofs + sizeof(*mspi->tx_bd));
 369
 370         /* Initialize parameter ram. */
 371         iowrite16be(cpm_muram_offset(mspi->tx_bd), &mspi->pram->tbase);
 372         iowrite16be(cpm_muram_offset(mspi->rx_bd), &mspi->pram->rbase);
 373         iowrite8(CPMFCR_EB | CPMFCR_GBL, &mspi->pram->tfcr);
 374         iowrite8(CPMFCR_EB | CPMFCR_GBL, &mspi->pram->rfcr);
 375         iowrite16be(SPI_MRBLR, &mspi->pram->mrblr);
 376         iowrite32be(0, &mspi->pram->rstate);
 377         iowrite32be(0, &mspi->pram->rdp);
 378         iowrite16be(0, &mspi->pram->rbptr);
 379         iowrite16be(0, &mspi->pram->rbc);
 380         iowrite32be(0, &mspi->pram->rxtmp);
 381         iowrite32be(0, &mspi->pram->tstate);
 382         iowrite32be(0, &mspi->pram->tdp);
 383         iowrite16be(0, &mspi->pram->tbptr);
 384         iowrite16be(0, &mspi->pram->tbc);
 385         iowrite32be(0, &mspi->pram->txtmp);
 386
 387         return 0;
 388
 389 err_dummy_rx:
 390         dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
 391 err_dummy_tx:
 392         cpm_muram_free(bds_ofs);
 393 err_bds:
 394         if (!(mspi->flags & SPI_CPM1))
 395                 cpm_muram_free(cpm_muram_offset(mspi->pram));
 396 err_pram:
 397         fsl_spi_free_dummy_rx();
 398         return -ENOMEM;
 399 }
 400 EXPORT_SYMBOL_GPL(fsl_spi_cpm_init);
 401
 402 void fsl_spi_cpm_free(struct mpc8xxx_spi *mspi)
 403 {
 404         struct device *dev = mspi->dev;
 405
 406         if (!(mspi->flags & SPI_CPM_MODE))
 407                 return;
 408
 409         dma_unmap_single(dev, mspi->dma_dummy_rx, SPI_MRBLR, DMA_FROM_DEVICE);
 410         dma_unmap_single(dev, mspi->dma_dummy_tx, PAGE_SIZE, DMA_TO_DEVICE);
 411         cpm_muram_free(cpm_muram_offset(mspi->tx_bd));
 412         if (!(mspi->flags & SPI_CPM1))
 413                 cpm_muram_free(cpm_muram_offset(mspi->pram));
 414         fsl_spi_free_dummy_rx();
 415 }
 416 EXPORT_SYMBOL_GPL(fsl_spi_cpm_free);
 417
 418 MODULE_DESCRIPTION("Freescale SPI controller driver CPM functions");
 419 MODULE_LICENSE("GPL");