drivers/spi/spi-ingenic.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SPI bus driver for the Ingenic SoCs
   4  * Copyright (c) 2017-2021 Artur Rojek <contact@artur-rojek.eu>
   5  * Copyright (c) 2017-2021 Paul Cercueil <paul@crapouillou.net>
   6  * Copyright (c) 2022 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/delay.h>
  11 #include <linux/dmaengine.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/iopoll.h>
  14 #include <linux/module.h>
  15 #include <linux/of_device.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/regmap.h>
  18 #include <linux/spi/spi.h>
  19
  20 #define REG_SSIDR       0x0
  21 #define REG_SSICR0      0x4
  22 #define REG_SSICR1      0x8
  23 #define REG_SSISR       0xc
  24 #define REG_SSIGR       0x18
  25
  26 #define REG_SSICR0_TENDIAN_LSB          BIT(19)
  27 #define REG_SSICR0_RENDIAN_LSB          BIT(17)
  28 #define REG_SSICR0_SSIE                 BIT(15)
  29 #define REG_SSICR0_LOOP                 BIT(10)
  30 #define REG_SSICR0_EACLRUN              BIT(7)
  31 #define REG_SSICR0_FSEL                 BIT(6)
  32 #define REG_SSICR0_TFLUSH               BIT(2)
  33 #define REG_SSICR0_RFLUSH               BIT(1)
  34
  35 #define REG_SSICR1_FRMHL_MASK           (BIT(31) | BIT(30))
  36 #define REG_SSICR1_FRMHL                BIT(30)
  37 #define REG_SSICR1_LFST                 BIT(25)
  38 #define REG_SSICR1_UNFIN                BIT(23)
  39 #define REG_SSICR1_PHA                  BIT(1)
  40 #define REG_SSICR1_POL                  BIT(0)
  41
  42 #define REG_SSISR_END                   BIT(7)
  43 #define REG_SSISR_BUSY                  BIT(6)
  44 #define REG_SSISR_TFF                   BIT(5)
  45 #define REG_SSISR_RFE                   BIT(4)
  46 #define REG_SSISR_RFHF                  BIT(2)
  47 #define REG_SSISR_UNDR                  BIT(1)
  48 #define REG_SSISR_OVER                  BIT(0)
  49
  50 #define SPI_INGENIC_FIFO_SIZE           128u
  51
  52 struct jz_soc_info {
  53         u32 bits_per_word_mask;
  54         struct reg_field flen_field;
  55         bool has_trendian;
  56
  57         unsigned int max_speed_hz;
  58         unsigned int max_native_cs;
  59 };
  60
  61 struct ingenic_spi {
  62         const struct jz_soc_info *soc_info;
  63         struct clk *clk;
  64         struct resource *mem_res;
  65
  66         struct regmap *map;
  67         struct regmap_field *flen_field;
  68 };
  69
  70 static int spi_ingenic_wait(struct ingenic_spi *priv,
  71                             unsigned long mask,
  72                             bool condition)
  73 {
  74         unsigned int val;
  75
  76         return regmap_read_poll_timeout(priv->map, REG_SSISR, val,
  77                                         !!(val & mask) == condition,
  78                                         100, 10000);
  79 }
  80
  81 static void spi_ingenic_set_cs(struct spi_device *spi, bool disable)
  82 {
  83         struct ingenic_spi *priv = spi_controller_get_devdata(spi->controller);
  84
  85         if (disable) {
  86                 regmap_clear_bits(priv->map, REG_SSICR1, REG_SSICR1_UNFIN);
  87                 regmap_clear_bits(priv->map, REG_SSISR,
  88                                   REG_SSISR_UNDR | REG_SSISR_OVER);
  89
  90                 spi_ingenic_wait(priv, REG_SSISR_END, true);
  91         } else {
  92                 regmap_set_bits(priv->map, REG_SSICR1, REG_SSICR1_UNFIN);
  93         }
  94
  95         regmap_set_bits(priv->map, REG_SSICR0,
  96                         REG_SSICR0_RFLUSH | REG_SSICR0_TFLUSH);
  97 }
  98
  99 static void spi_ingenic_prepare_transfer(struct ingenic_spi *priv,
 100                                          struct spi_device *spi,
 101                                          struct spi_transfer *xfer)
 102 {
 103         unsigned long clk_hz = clk_get_rate(priv->clk);
 104         u32 cdiv, speed_hz = xfer->speed_hz ?: spi->max_speed_hz,
 105             bits_per_word = xfer->bits_per_word ?: spi->bits_per_word;
 106
 107         cdiv = clk_hz / (speed_hz * 2);
 108         cdiv = clamp(cdiv, 1u, 0x100u) - 1;
 109
 110         regmap_write(priv->map, REG_SSIGR, cdiv);
 111
 112         regmap_field_write(priv->flen_field, bits_per_word - 2);
 113 }
 114
 115 static void spi_ingenic_finalize_transfer(void *controller)
 116 {
 117         spi_finalize_current_transfer(controller);
 118 }
 119
 120 static struct dma_async_tx_descriptor *
 121 spi_ingenic_prepare_dma(struct spi_controller *ctlr, struct dma_chan *chan,
 122                         struct sg_table *sg, enum dma_transfer_direction dir,
 123                         unsigned int bits)
 124 {
 125         struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
 126         struct dma_slave_config cfg = {
 127                 .direction = dir,
 128                 .src_addr = priv->mem_res->start + REG_SSIDR,
 129                 .dst_addr = priv->mem_res->start + REG_SSIDR,
 130         };
 131         struct dma_async_tx_descriptor *desc;
 132         dma_cookie_t cookie;
 133         int ret;
 134
 135         if (bits > 16) {
 136                 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 137                 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 138                 cfg.src_maxburst = cfg.dst_maxburst = 4;
 139         } else if (bits > 8) {
 140                 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 141                 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 142                 cfg.src_maxburst = cfg.dst_maxburst = 2;
 143         } else {
 144                 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 145                 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 146                 cfg.src_maxburst = cfg.dst_maxburst = 1;
 147         }
 148
 149         ret = dmaengine_slave_config(chan, &cfg);
 150         if (ret)
 151                 return ERR_PTR(ret);
 152
 153         desc = dmaengine_prep_slave_sg(chan, sg->sgl, sg->nents, dir,
 154                                        DMA_PREP_INTERRUPT);
 155         if (!desc)
 156                 return ERR_PTR(-ENOMEM);
 157
 158         if (dir == DMA_DEV_TO_MEM) {
 159                 desc->callback = spi_ingenic_finalize_transfer;
 160                 desc->callback_param = ctlr;
 161         }
 162
 163         cookie = dmaengine_submit(desc);
 164
 165         ret = dma_submit_error(cookie);
 166         if (ret) {
 167                 dmaengine_desc_free(desc);
 168                 return ERR_PTR(ret);
 169         }
 170
 171         return desc;
 172 }
 173
 174 static int spi_ingenic_dma_tx(struct spi_controller *ctlr,
 175                               struct spi_transfer *xfer, unsigned int bits)
 176 {
 177         struct dma_async_tx_descriptor *rx_desc, *tx_desc;
 178
 179         rx_desc = spi_ingenic_prepare_dma(ctlr, ctlr->dma_rx,
 180                                           &xfer->rx_sg, DMA_DEV_TO_MEM, bits);
 181         if (IS_ERR(rx_desc))
 182                 return PTR_ERR(rx_desc);
 183
 184         tx_desc = spi_ingenic_prepare_dma(ctlr, ctlr->dma_tx,
 185                                           &xfer->tx_sg, DMA_MEM_TO_DEV, bits);
 186         if (IS_ERR(tx_desc)) {
 187                 dmaengine_terminate_async(ctlr->dma_rx);
 188                 dmaengine_desc_free(rx_desc);
 189                 return PTR_ERR(tx_desc);
 190         }
 191
 192         dma_async_issue_pending(ctlr->dma_rx);
 193         dma_async_issue_pending(ctlr->dma_tx);
 194
 195         return 1;
 196 }
 197
 198 #define SPI_INGENIC_TX(x)                                                       \
 199 static int spi_ingenic_tx##x(struct ingenic_spi *priv,                          \
 200                              struct spi_transfer *xfer)                         \
 201 {                                                                               \
 202         unsigned int count = xfer->len / (x / 8);                               \
 203         unsigned int prefill = min(count, SPI_INGENIC_FIFO_SIZE);               \
 204         const u##x *tx_buf = xfer->tx_buf;                                      \
 205         u##x *rx_buf = xfer->rx_buf;                                            \
 206         unsigned int i, val;                                                    \
 207         int err;                                                                \
 208                                                                                 \
 209         /* Fill up the TX fifo */                                               \
 210         for (i = 0; i < prefill; i++) {                                         \
 211                 val = tx_buf ? tx_buf[i] : 0;                                   \
 212                                                                                 \
 213                 regmap_write(priv->map, REG_SSIDR, val);                        \
 214         }                                                                       \
 215                                                                                 \
 216         for (i = 0; i < count; i++) {                                           \
 217                 err = spi_ingenic_wait(priv, REG_SSISR_RFE, false);             \
 218                 if (err)                                                        \
 219                         return err;                                             \
 220                                                                                 \
 221                 regmap_read(priv->map, REG_SSIDR, &val);                        \
 222                 if (rx_buf)                                                     \
 223                         rx_buf[i] = val;                                        \
 224                                                                                 \
 225                 if (i < count - prefill) {                                      \
 226                         val = tx_buf ? tx_buf[i + prefill] : 0;                 \
 227                                                                                 \
 228                         regmap_write(priv->map, REG_SSIDR, val);                \
 229                 }                                                               \
 230         }                                                                       \
 231                                                                                 \
 232         return 0;                                                               \
 233 }
 234 SPI_INGENIC_TX(8)
 235 SPI_INGENIC_TX(16)
 236 SPI_INGENIC_TX(32)
 237 #undef SPI_INGENIC_TX
 238
 239 static int spi_ingenic_transfer_one(struct spi_controller *ctlr,
 240                                     struct spi_device *spi,
 241                                     struct spi_transfer *xfer)
 242 {
 243         struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
 244         unsigned int bits = xfer->bits_per_word ?: spi->bits_per_word;
 245         bool can_dma = ctlr->can_dma && ctlr->can_dma(ctlr, spi, xfer);
 246
 247         spi_ingenic_prepare_transfer(priv, spi, xfer);
 248
 249         if (ctlr->cur_msg_mapped && can_dma)
 250                 return spi_ingenic_dma_tx(ctlr, xfer, bits);
 251
 252         if (bits > 16)
 253                 return spi_ingenic_tx32(priv, xfer);
 254
 255         if (bits > 8)
 256                 return spi_ingenic_tx16(priv, xfer);
 257
 258         return spi_ingenic_tx8(priv, xfer);
 259 }
 260
 261 static int spi_ingenic_prepare_message(struct spi_controller *ctlr,
 262                                        struct spi_message *message)
 263 {
 264         struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
 265         struct spi_device *spi = message->spi;
 266         unsigned int cs = REG_SSICR1_FRMHL << spi->chip_select;
 267         unsigned int ssicr0_mask = REG_SSICR0_LOOP | REG_SSICR0_FSEL;
 268         unsigned int ssicr1_mask = REG_SSICR1_PHA | REG_SSICR1_POL | cs;
 269         unsigned int ssicr0 = 0, ssicr1 = 0;
 270
 271         if (priv->soc_info->has_trendian) {
 272                 ssicr0_mask |= REG_SSICR0_RENDIAN_LSB | REG_SSICR0_TENDIAN_LSB;
 273
 274                 if (spi->mode & SPI_LSB_FIRST)
 275                         ssicr0 |= REG_SSICR0_RENDIAN_LSB | REG_SSICR0_TENDIAN_LSB;
 276         } else {
 277                 ssicr1_mask |= REG_SSICR1_LFST;
 278
 279                 if (spi->mode & SPI_LSB_FIRST)
 280                         ssicr1 |= REG_SSICR1_LFST;
 281         }
 282
 283         if (spi->mode & SPI_LOOP)
 284                 ssicr0 |= REG_SSICR0_LOOP;
 285         if (spi->chip_select)
 286                 ssicr0 |= REG_SSICR0_FSEL;
 287
 288         if (spi->mode & SPI_CPHA)
 289                 ssicr1 |= REG_SSICR1_PHA;
 290         if (spi->mode & SPI_CPOL)
 291                 ssicr1 |= REG_SSICR1_POL;
 292         if (spi->mode & SPI_CS_HIGH)
 293                 ssicr1 |= cs;
 294
 295         regmap_update_bits(priv->map, REG_SSICR0, ssicr0_mask, ssicr0);
 296         regmap_update_bits(priv->map, REG_SSICR1, ssicr1_mask, ssicr1);
 297
 298         return 0;
 299 }
 300
 301 static int spi_ingenic_prepare_hardware(struct spi_controller *ctlr)
 302 {
 303         struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
 304         int ret;
 305
 306         ret = clk_prepare_enable(priv->clk);
 307         if (ret)
 308                 return ret;
 309
 310         regmap_write(priv->map, REG_SSICR0, REG_SSICR0_EACLRUN);
 311         regmap_write(priv->map, REG_SSICR1, 0);
 312         regmap_write(priv->map, REG_SSISR, 0);
 313         regmap_set_bits(priv->map, REG_SSICR0, REG_SSICR0_SSIE);
 314
 315         return 0;
 316 }
 317
 318 static int spi_ingenic_unprepare_hardware(struct spi_controller *ctlr)
 319 {
 320         struct ingenic_spi *priv = spi_controller_get_devdata(ctlr);
 321
 322         regmap_clear_bits(priv->map, REG_SSICR0, REG_SSICR0_SSIE);
 323
 324         clk_disable_unprepare(priv->clk);
 325
 326         return 0;
 327 }
 328
 329 static bool spi_ingenic_can_dma(struct spi_controller *ctlr,
 330                                 struct spi_device *spi,
 331                                 struct spi_transfer *xfer)
 332 {
 333         struct dma_slave_caps caps;
 334         int ret;
 335
 336         ret = dma_get_slave_caps(ctlr->dma_tx, &caps);
 337         if (ret) {
 338                 dev_err(&spi->dev, "Unable to get slave caps: %d\n", ret);
 339                 return false;
 340         }
 341
 342         return !caps.max_sg_burst ||
 343                 xfer->len <= caps.max_sg_burst * SPI_INGENIC_FIFO_SIZE;
 344 }
 345
 346 static int spi_ingenic_request_dma(struct spi_controller *ctlr,
 347                                    struct device *dev)
 348 {
 349         ctlr->dma_tx = dma_request_slave_channel(dev, "tx");
 350         if (!ctlr->dma_tx)
 351                 return -ENODEV;
 352
 353         ctlr->dma_rx = dma_request_slave_channel(dev, "rx");
 354
 355         if (!ctlr->dma_rx)
 356                 return -ENODEV;
 357
 358         ctlr->can_dma = spi_ingenic_can_dma;
 359
 360         return 0;
 361 }
 362
 363 static void spi_ingenic_release_dma(void *data)
 364 {
 365         struct spi_controller *ctlr = data;
 366
 367         if (ctlr->dma_tx)
 368                 dma_release_channel(ctlr->dma_tx);
 369         if (ctlr->dma_rx)
 370                 dma_release_channel(ctlr->dma_rx);
 371 }
 372
 373 static const struct regmap_config spi_ingenic_regmap_config = {
 374         .reg_bits = 32,
 375         .val_bits = 32,
 376         .reg_stride = 4,
 377         .max_register = REG_SSIGR,
 378 };
 379
 380 static int spi_ingenic_probe(struct platform_device *pdev)
 381 {
 382         const struct jz_soc_info *pdata;
 383         struct device *dev = &pdev->dev;
 384         struct spi_controller *ctlr;
 385         struct ingenic_spi *priv;
 386         void __iomem *base;
 387         int num_cs, ret;
 388
 389         pdata = of_device_get_match_data(dev);
 390         if (!pdata) {
 391                 dev_err(dev, "Missing platform data.\n");
 392                 return -EINVAL;
 393         }
 394
 395         ctlr = devm_spi_alloc_master(dev, sizeof(*priv));
 396         if (!ctlr) {
 397                 dev_err(dev, "Unable to allocate SPI controller.\n");
 398                 return -ENOMEM;
 399         }
 400
 401         priv = spi_controller_get_devdata(ctlr);
 402         priv->soc_info = pdata;
 403
 404         priv->clk = devm_clk_get(dev, NULL);
 405         if (IS_ERR(priv->clk)) {
 406                 return dev_err_probe(dev, PTR_ERR(priv->clk),
 407                                      "Unable to get clock.\n");
 408         }
 409
 410         base = devm_platform_get_and_ioremap_resource(pdev, 0, &priv->mem_res);
 411         if (IS_ERR(base))
 412                 return PTR_ERR(base);
 413
 414         priv->map = devm_regmap_init_mmio(dev, base, &spi_ingenic_regmap_config);
 415         if (IS_ERR(priv->map))
 416                 return PTR_ERR(priv->map);
 417
 418         priv->flen_field = devm_regmap_field_alloc(dev, priv->map,
 419                                                    pdata->flen_field);
 420         if (IS_ERR(priv->flen_field))
 421                 return PTR_ERR(priv->flen_field);
 422
 423         if (device_property_read_u32(dev, "num-cs", &num_cs))
 424                 num_cs = pdata->max_native_cs;
 425
 426         platform_set_drvdata(pdev, ctlr);
 427
 428         ctlr->prepare_transfer_hardware = spi_ingenic_prepare_hardware;
 429         ctlr->unprepare_transfer_hardware = spi_ingenic_unprepare_hardware;
 430         ctlr->prepare_message = spi_ingenic_prepare_message;
 431         ctlr->set_cs = spi_ingenic_set_cs;
 432         ctlr->transfer_one = spi_ingenic_transfer_one;
 433         ctlr->mode_bits = SPI_MODE_3 | SPI_LSB_FIRST | SPI_LOOP | SPI_CS_HIGH;
 434         ctlr->flags = SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX;
 435         ctlr->max_dma_len = SPI_INGENIC_FIFO_SIZE;
 436         ctlr->bits_per_word_mask = pdata->bits_per_word_mask;
 437         ctlr->min_speed_hz = 7200;
 438         ctlr->max_speed_hz = pdata->max_speed_hz;
 439         ctlr->use_gpio_descriptors = true;
 440         ctlr->max_native_cs = pdata->max_native_cs;
 441         ctlr->num_chipselect = num_cs;
 442         ctlr->dev.of_node = pdev->dev.of_node;
 443
 444         if (spi_ingenic_request_dma(ctlr, dev))
 445                 dev_warn(dev, "DMA not available.\n");
 446
 447         ret = devm_add_action_or_reset(dev, spi_ingenic_release_dma, ctlr);
 448         if (ret) {
 449                 dev_err(dev, "Unable to add action.\n");
 450                 return ret;
 451         }
 452
 453         ret = devm_spi_register_controller(dev, ctlr);
 454         if (ret)
 455                 dev_err(dev, "Unable to register SPI controller.\n");
 456
 457         return ret;
 458 }
 459
 460 static const struct jz_soc_info jz4750_soc_info = {
 461         .bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 17),
 462         .flen_field = REG_FIELD(REG_SSICR1, 4, 7),
 463         .has_trendian = false,
 464
 465         .max_speed_hz = 54000000,
 466         .max_native_cs = 2,
 467 };
 468
 469 static const struct jz_soc_info jz4780_soc_info = {
 470         .bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 32),
 471         .flen_field = REG_FIELD(REG_SSICR1, 3, 7),
 472         .has_trendian = true,
 473
 474         .max_speed_hz = 54000000,
 475         .max_native_cs = 2,
 476 };
 477
 478 static const struct jz_soc_info x1000_soc_info = {
 479         .bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 32),
 480         .flen_field = REG_FIELD(REG_SSICR1, 3, 7),
 481         .has_trendian = true,
 482
 483         .max_speed_hz = 50000000,
 484         .max_native_cs = 2,
 485 };
 486
 487 static const struct jz_soc_info x2000_soc_info = {
 488         .bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 32),
 489         .flen_field = REG_FIELD(REG_SSICR1, 3, 7),
 490         .has_trendian = true,
 491
 492         .max_speed_hz = 50000000,
 493         .max_native_cs = 1,
 494 };
 495
 496 static const struct of_device_id spi_ingenic_of_match[] = {
 497         { .compatible = "ingenic,jz4750-spi", .data = &jz4750_soc_info },
 498         { .compatible = "ingenic,jz4775-spi", .data = &jz4780_soc_info },
 499         { .compatible = "ingenic,jz4780-spi", .data = &jz4780_soc_info },
 500         { .compatible = "ingenic,x1000-spi", .data = &x1000_soc_info },
 501         { .compatible = "ingenic,x2000-spi", .data = &x2000_soc_info },
 502         {}
 503 };
 504 MODULE_DEVICE_TABLE(of, spi_ingenic_of_match);
 505
 506 static struct platform_driver spi_ingenic_driver = {
 507         .driver = {
 508                 .name = "spi-ingenic",
 509                 .of_match_table = spi_ingenic_of_match,
 510         },
 511         .probe = spi_ingenic_probe,
 512 };
 513
 514 module_platform_driver(spi_ingenic_driver);
 515 MODULE_DESCRIPTION("SPI bus driver for the Ingenic SoCs");
 516 MODULE_AUTHOR("Artur Rojek <contact@artur-rojek.eu>");
 517 MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
 518 MODULE_AUTHOR("周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>");
 519 MODULE_LICENSE("GPL");