1 // SPDX-License-Identifier: GPL-2.0 2 // spi-uniphier.c - Socionext UniPhier SPI controller driver 3 // Copyright 2012 Panasonic Corporation 4 // Copyright 2016-2018 Socionext Inc. 5 6 #include <linux/kernel.h> 7 #include <linux/bitfield.h> 8 #include <linux/bitops.h> 9 #include <linux/clk.h> 10 #include <linux/delay.h> 11 #include <linux/dmaengine.h> 12 #include <linux/interrupt.h> 13 #include <linux/io.h> 14 #include <linux/module.h> 15 #include <linux/platform_device.h> 16 #include <linux/spi/spi.h> 17 18 #include <asm/unaligned.h> 19 20 #define SSI_TIMEOUT_MS 2000 21 #define SSI_POLL_TIMEOUT_US 200 22 #define SSI_MAX_CLK_DIVIDER 254 23 #define SSI_MIN_CLK_DIVIDER 4 24 25 struct uniphier_spi_priv { 26 void __iomem *base; 27 dma_addr_t base_dma_addr; 28 struct clk *clk; 29 struct spi_master *master; 30 struct completion xfer_done; 31 32 int error; 33 unsigned int tx_bytes; 34 unsigned int rx_bytes; 35 const u8 *tx_buf; 36 u8 *rx_buf; 37 atomic_t dma_busy; 38 39 bool is_save_param; 40 u8 bits_per_word; 41 u16 mode; 42 u32 speed_hz; 43 }; 44 45 #define SSI_CTL 0x00 46 #define SSI_CTL_EN BIT(0) 47 48 #define SSI_CKS 0x04 49 #define SSI_CKS_CKRAT_MASK GENMASK(7, 0) 50 #define SSI_CKS_CKPHS BIT(14) 51 #define SSI_CKS_CKINIT BIT(13) 52 #define SSI_CKS_CKDLY BIT(12) 53 54 #define SSI_TXWDS 0x08 55 #define SSI_TXWDS_WDLEN_MASK GENMASK(13, 8) 56 #define SSI_TXWDS_TDTF_MASK GENMASK(7, 6) 57 #define SSI_TXWDS_DTLEN_MASK GENMASK(5, 0) 58 59 #define SSI_RXWDS 0x0c 60 #define SSI_RXWDS_DTLEN_MASK GENMASK(5, 0) 61 62 #define SSI_FPS 0x10 63 #define SSI_FPS_FSPOL BIT(15) 64 #define SSI_FPS_FSTRT BIT(14) 65 66 #define SSI_SR 0x14 67 #define SSI_SR_BUSY BIT(7) 68 #define SSI_SR_RNE BIT(0) 69 70 #define SSI_IE 0x18 71 #define SSI_IE_TCIE BIT(4) 72 #define SSI_IE_RCIE BIT(3) 73 #define SSI_IE_TXRE BIT(2) 74 #define SSI_IE_RXRE BIT(1) 75 #define SSI_IE_RORIE BIT(0) 76 #define SSI_IE_ALL_MASK GENMASK(4, 0) 77 78 #define SSI_IS 0x1c 79 #define SSI_IS_RXRS BIT(9) 80 #define SSI_IS_RCID BIT(3) 81 #define SSI_IS_RORID BIT(0) 82 83 #define SSI_IC 0x1c 84 #define SSI_IC_TCIC BIT(4) 85 #define SSI_IC_RCIC BIT(3) 86 #define SSI_IC_RORIC BIT(0) 87 88 #define SSI_FC 0x20 89 #define SSI_FC_TXFFL BIT(12) 90 #define SSI_FC_TXFTH_MASK GENMASK(11, 8) 91 #define SSI_FC_RXFFL BIT(4) 92 #define SSI_FC_RXFTH_MASK GENMASK(3, 0) 93 94 #define SSI_TXDR 0x24 95 #define SSI_RXDR 0x24 96 97 #define SSI_FIFO_DEPTH 8U 98 #define SSI_FIFO_BURST_NUM 1 99 100 #define SSI_DMA_RX_BUSY BIT(1) 101 #define SSI_DMA_TX_BUSY BIT(0) 102 103 static inline unsigned int bytes_per_word(unsigned int bits) 104 { 105 return bits <= 8 ? 1 : (bits <= 16 ? 2 : 4); 106 } 107 108 static inline void uniphier_spi_irq_enable(struct uniphier_spi_priv *priv, 109 u32 mask) 110 { 111 u32 val; 112 113 val = readl(priv->base + SSI_IE); 114 val |= mask; 115 writel(val, priv->base + SSI_IE); 116 } 117 118 static inline void uniphier_spi_irq_disable(struct uniphier_spi_priv *priv, 119 u32 mask) 120 { 121 u32 val; 122 123 val = readl(priv->base + SSI_IE); 124 val &= ~mask; 125 writel(val, priv->base + SSI_IE); 126 } 127 128 static void uniphier_spi_set_mode(struct spi_device *spi) 129 { 130 struct uniphier_spi_priv *priv = spi_master_get_devdata(spi->master); 131 u32 val1, val2; 132 133 /* 134 * clock setting 135 * CKPHS capture timing. 0:rising edge, 1:falling edge 136 * CKINIT clock initial level. 0:low, 1:high 137 * CKDLY clock delay. 0:no delay, 1:delay depending on FSTRT 138 * (FSTRT=0: 1 clock, FSTRT=1: 0.5 clock) 139 * 140 * frame setting 141 * FSPOL frame signal porarity. 0: low, 1: high 142 * FSTRT start frame timing 143 * 0: rising edge of clock, 1: falling edge of clock 144 */ 145 switch (spi->mode & SPI_MODE_X_MASK) { 146 case SPI_MODE_0: 147 /* CKPHS=1, CKINIT=0, CKDLY=1, FSTRT=0 */ 148 val1 = SSI_CKS_CKPHS | SSI_CKS_CKDLY; 149 val2 = 0; 150 break; 151 case SPI_MODE_1: 152 /* CKPHS=0, CKINIT=0, CKDLY=0, FSTRT=1 */ 153 val1 = 0; 154 val2 = SSI_FPS_FSTRT; 155 break; 156 case SPI_MODE_2: 157 /* CKPHS=0, CKINIT=1, CKDLY=1, FSTRT=1 */ 158 val1 = SSI_CKS_CKINIT | SSI_CKS_CKDLY; 159 val2 = SSI_FPS_FSTRT; 160 break; 161 case SPI_MODE_3: 162 /* CKPHS=1, CKINIT=1, CKDLY=0, FSTRT=0 */ 163 val1 = SSI_CKS_CKPHS | SSI_CKS_CKINIT; 164 val2 = 0; 165 break; 166 } 167 168 if (!(spi->mode & SPI_CS_HIGH)) 169 val2 |= SSI_FPS_FSPOL; 170 171 writel(val1, priv->base + SSI_CKS); 172 writel(val2, priv->base + SSI_FPS); 173 174 val1 = 0; 175 if (spi->mode & SPI_LSB_FIRST) 176 val1 |= FIELD_PREP(SSI_TXWDS_TDTF_MASK, 1); 177 writel(val1, priv->base + SSI_TXWDS); 178 writel(val1, priv->base + SSI_RXWDS); 179 } 180 181 static void uniphier_spi_set_transfer_size(struct spi_device *spi, int size) 182 { 183 struct uniphier_spi_priv *priv = spi_master_get_devdata(spi->master); 184 u32 val; 185 186 val = readl(priv->base + SSI_TXWDS); 187 val &= ~(SSI_TXWDS_WDLEN_MASK | SSI_TXWDS_DTLEN_MASK); 188 val |= FIELD_PREP(SSI_TXWDS_WDLEN_MASK, size); 189 val |= FIELD_PREP(SSI_TXWDS_DTLEN_MASK, size); 190 writel(val, priv->base + SSI_TXWDS); 191 192 val = readl(priv->base + SSI_RXWDS); 193 val &= ~SSI_RXWDS_DTLEN_MASK; 194 val |= FIELD_PREP(SSI_RXWDS_DTLEN_MASK, size); 195 writel(val, priv->base + SSI_RXWDS); 196 } 197 198 static void uniphier_spi_set_baudrate(struct spi_device *spi, 199 unsigned int speed) 200 { 201 struct uniphier_spi_priv *priv = spi_master_get_devdata(spi->master); 202 u32 val, ckdiv; 203 204 /* 205 * the supported rates are even numbers from 4 to 254. (4,6,8...254) 206 * round up as we look for equal or less speed 207 */ 208 ckdiv = DIV_ROUND_UP(clk_get_rate(priv->clk), speed); 209 ckdiv = round_up(ckdiv, 2); 210 211 val = readl(priv->base + SSI_CKS); 212 val &= ~SSI_CKS_CKRAT_MASK; 213 val |= ckdiv & SSI_CKS_CKRAT_MASK; 214 writel(val, priv->base + SSI_CKS); 215 } 216 217 static void uniphier_spi_setup_transfer(struct spi_device *spi, 218 struct spi_transfer *t) 219 { 220 struct uniphier_spi_priv *priv = spi_master_get_devdata(spi->master); 221 u32 val; 222 223 priv->error = 0; 224 priv->tx_buf = t->tx_buf; 225 priv->rx_buf = t->rx_buf; 226 priv->tx_bytes = priv->rx_bytes = t->len; 227 228 if (!priv->is_save_param || priv->mode != spi->mode) { 229 uniphier_spi_set_mode(spi); 230 priv->mode = spi->mode; 231 priv->is_save_param = false; 232 } 233 234 if (!priv->is_save_param || priv->bits_per_word != t->bits_per_word) { 235 uniphier_spi_set_transfer_size(spi, t->bits_per_word); 236 priv->bits_per_word = t->bits_per_word; 237 } 238 239 if (!priv->is_save_param || priv->speed_hz != t->speed_hz) { 240 uniphier_spi_set_baudrate(spi, t->speed_hz); 241 priv->speed_hz = t->speed_hz; 242 } 243 244 priv->is_save_param = true; 245 246 /* reset FIFOs */ 247 val = SSI_FC_TXFFL | SSI_FC_RXFFL; 248 writel(val, priv->base + SSI_FC); 249 } 250 251 static void uniphier_spi_send(struct uniphier_spi_priv *priv) 252 { 253 int wsize; 254 u32 val = 0; 255 256 wsize = min(bytes_per_word(priv->bits_per_word), priv->tx_bytes); 257 priv->tx_bytes -= wsize; 258 259 if (priv->tx_buf) { 260 switch (wsize) { 261 case 1: 262 val = *priv->tx_buf; 263 break; 264 case 2: 265 val = get_unaligned_le16(priv->tx_buf); 266 break; 267 case 4: 268 val = get_unaligned_le32(priv->tx_buf); 269 break; 270 } 271 272 priv->tx_buf += wsize; 273 } 274 275 writel(val, priv->base + SSI_TXDR); 276 } 277 278 static void uniphier_spi_recv(struct uniphier_spi_priv *priv) 279 { 280 int rsize; 281 u32 val; 282 283 rsize = min(bytes_per_word(priv->bits_per_word), priv->rx_bytes); 284 priv->rx_bytes -= rsize; 285 286 val = readl(priv->base + SSI_RXDR); 287 288 if (priv->rx_buf) { 289 switch (rsize) { 290 case 1: 291 *priv->rx_buf = val; 292 break; 293 case 2: 294 put_unaligned_le16(val, priv->rx_buf); 295 break; 296 case 4: 297 put_unaligned_le32(val, priv->rx_buf); 298 break; 299 } 300 301 priv->rx_buf += rsize; 302 } 303 } 304 305 static void uniphier_spi_set_fifo_threshold(struct uniphier_spi_priv *priv, 306 unsigned int threshold) 307 { 308 u32 val; 309 310 val = readl(priv->base + SSI_FC); 311 val &= ~(SSI_FC_TXFTH_MASK | SSI_FC_RXFTH_MASK); 312 val |= FIELD_PREP(SSI_FC_TXFTH_MASK, SSI_FIFO_DEPTH - threshold); 313 val |= FIELD_PREP(SSI_FC_RXFTH_MASK, threshold); 314 writel(val, priv->base + SSI_FC); 315 } 316 317 static void uniphier_spi_fill_tx_fifo(struct uniphier_spi_priv *priv) 318 { 319 unsigned int fifo_threshold, fill_words; 320 unsigned int bpw = bytes_per_word(priv->bits_per_word); 321 322 fifo_threshold = DIV_ROUND_UP(priv->rx_bytes, bpw); 323 fifo_threshold = min(fifo_threshold, SSI_FIFO_DEPTH); 324 325 uniphier_spi_set_fifo_threshold(priv, fifo_threshold); 326 327 fill_words = fifo_threshold - 328 DIV_ROUND_UP(priv->rx_bytes - priv->tx_bytes, bpw); 329 330 while (fill_words--) 331 uniphier_spi_send(priv); 332 } 333 334 static void uniphier_spi_set_cs(struct spi_device *spi, bool enable) 335 { 336 struct uniphier_spi_priv *priv = spi_master_get_devdata(spi->master); 337 u32 val; 338 339 val = readl(priv->base + SSI_FPS); 340 341 if (enable) 342 val |= SSI_FPS_FSPOL; 343 else 344 val &= ~SSI_FPS_FSPOL; 345 346 writel(val, priv->base + SSI_FPS); 347 } 348 349 static bool uniphier_spi_can_dma(struct spi_master *master, 350 struct spi_device *spi, 351 struct spi_transfer *t) 352 { 353 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 354 unsigned int bpw = bytes_per_word(priv->bits_per_word); 355 356 if ((!master->dma_tx && !master->dma_rx) 357 || (!master->dma_tx && t->tx_buf) 358 || (!master->dma_rx && t->rx_buf)) 359 return false; 360 361 return DIV_ROUND_UP(t->len, bpw) > SSI_FIFO_DEPTH; 362 } 363 364 static void uniphier_spi_dma_rxcb(void *data) 365 { 366 struct spi_master *master = data; 367 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 368 int state = atomic_fetch_andnot(SSI_DMA_RX_BUSY, &priv->dma_busy); 369 370 uniphier_spi_irq_disable(priv, SSI_IE_RXRE); 371 372 if (!(state & SSI_DMA_TX_BUSY)) 373 spi_finalize_current_transfer(master); 374 } 375 376 static void uniphier_spi_dma_txcb(void *data) 377 { 378 struct spi_master *master = data; 379 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 380 int state = atomic_fetch_andnot(SSI_DMA_TX_BUSY, &priv->dma_busy); 381 382 uniphier_spi_irq_disable(priv, SSI_IE_TXRE); 383 384 if (!(state & SSI_DMA_RX_BUSY)) 385 spi_finalize_current_transfer(master); 386 } 387 388 static int uniphier_spi_transfer_one_dma(struct spi_master *master, 389 struct spi_device *spi, 390 struct spi_transfer *t) 391 { 392 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 393 struct dma_async_tx_descriptor *rxdesc = NULL, *txdesc = NULL; 394 int buswidth; 395 396 atomic_set(&priv->dma_busy, 0); 397 398 uniphier_spi_set_fifo_threshold(priv, SSI_FIFO_BURST_NUM); 399 400 if (priv->bits_per_word <= 8) 401 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; 402 else if (priv->bits_per_word <= 16) 403 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; 404 else 405 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; 406 407 if (priv->rx_buf) { 408 struct dma_slave_config rxconf = { 409 .direction = DMA_DEV_TO_MEM, 410 .src_addr = priv->base_dma_addr + SSI_RXDR, 411 .src_addr_width = buswidth, 412 .src_maxburst = SSI_FIFO_BURST_NUM, 413 }; 414 415 dmaengine_slave_config(master->dma_rx, &rxconf); 416 417 rxdesc = dmaengine_prep_slave_sg( 418 master->dma_rx, 419 t->rx_sg.sgl, t->rx_sg.nents, 420 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 421 if (!rxdesc) 422 goto out_err_prep; 423 424 rxdesc->callback = uniphier_spi_dma_rxcb; 425 rxdesc->callback_param = master; 426 427 uniphier_spi_irq_enable(priv, SSI_IE_RXRE); 428 atomic_or(SSI_DMA_RX_BUSY, &priv->dma_busy); 429 430 dmaengine_submit(rxdesc); 431 dma_async_issue_pending(master->dma_rx); 432 } 433 434 if (priv->tx_buf) { 435 struct dma_slave_config txconf = { 436 .direction = DMA_MEM_TO_DEV, 437 .dst_addr = priv->base_dma_addr + SSI_TXDR, 438 .dst_addr_width = buswidth, 439 .dst_maxburst = SSI_FIFO_BURST_NUM, 440 }; 441 442 dmaengine_slave_config(master->dma_tx, &txconf); 443 444 txdesc = dmaengine_prep_slave_sg( 445 master->dma_tx, 446 t->tx_sg.sgl, t->tx_sg.nents, 447 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 448 if (!txdesc) 449 goto out_err_prep; 450 451 txdesc->callback = uniphier_spi_dma_txcb; 452 txdesc->callback_param = master; 453 454 uniphier_spi_irq_enable(priv, SSI_IE_TXRE); 455 atomic_or(SSI_DMA_TX_BUSY, &priv->dma_busy); 456 457 dmaengine_submit(txdesc); 458 dma_async_issue_pending(master->dma_tx); 459 } 460 461 /* signal that we need to wait for completion */ 462 return (priv->tx_buf || priv->rx_buf); 463 464 out_err_prep: 465 if (rxdesc) 466 dmaengine_terminate_sync(master->dma_rx); 467 468 return -EINVAL; 469 } 470 471 static int uniphier_spi_transfer_one_irq(struct spi_master *master, 472 struct spi_device *spi, 473 struct spi_transfer *t) 474 { 475 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 476 struct device *dev = master->dev.parent; 477 unsigned long time_left; 478 479 reinit_completion(&priv->xfer_done); 480 481 uniphier_spi_fill_tx_fifo(priv); 482 483 uniphier_spi_irq_enable(priv, SSI_IE_RCIE | SSI_IE_RORIE); 484 485 time_left = wait_for_completion_timeout(&priv->xfer_done, 486 msecs_to_jiffies(SSI_TIMEOUT_MS)); 487 488 uniphier_spi_irq_disable(priv, SSI_IE_RCIE | SSI_IE_RORIE); 489 490 if (!time_left) { 491 dev_err(dev, "transfer timeout.\n"); 492 return -ETIMEDOUT; 493 } 494 495 return priv->error; 496 } 497 498 static int uniphier_spi_transfer_one_poll(struct spi_master *master, 499 struct spi_device *spi, 500 struct spi_transfer *t) 501 { 502 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 503 int loop = SSI_POLL_TIMEOUT_US * 10; 504 505 while (priv->tx_bytes) { 506 uniphier_spi_fill_tx_fifo(priv); 507 508 while ((priv->rx_bytes - priv->tx_bytes) > 0) { 509 while (!(readl(priv->base + SSI_SR) & SSI_SR_RNE) 510 && loop--) 511 ndelay(100); 512 513 if (loop == -1) 514 goto irq_transfer; 515 516 uniphier_spi_recv(priv); 517 } 518 } 519 520 return 0; 521 522 irq_transfer: 523 return uniphier_spi_transfer_one_irq(master, spi, t); 524 } 525 526 static int uniphier_spi_transfer_one(struct spi_master *master, 527 struct spi_device *spi, 528 struct spi_transfer *t) 529 { 530 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 531 unsigned long threshold; 532 bool use_dma; 533 534 /* Terminate and return success for 0 byte length transfer */ 535 if (!t->len) 536 return 0; 537 538 uniphier_spi_setup_transfer(spi, t); 539 540 use_dma = master->can_dma ? master->can_dma(master, spi, t) : false; 541 if (use_dma) 542 return uniphier_spi_transfer_one_dma(master, spi, t); 543 544 /* 545 * If the transfer operation will take longer than 546 * SSI_POLL_TIMEOUT_US, it should use irq. 547 */ 548 threshold = DIV_ROUND_UP(SSI_POLL_TIMEOUT_US * priv->speed_hz, 549 USEC_PER_SEC * BITS_PER_BYTE); 550 if (t->len > threshold) 551 return uniphier_spi_transfer_one_irq(master, spi, t); 552 else 553 return uniphier_spi_transfer_one_poll(master, spi, t); 554 } 555 556 static int uniphier_spi_prepare_transfer_hardware(struct spi_master *master) 557 { 558 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 559 560 writel(SSI_CTL_EN, priv->base + SSI_CTL); 561 562 return 0; 563 } 564 565 static int uniphier_spi_unprepare_transfer_hardware(struct spi_master *master) 566 { 567 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 568 569 writel(0, priv->base + SSI_CTL); 570 571 return 0; 572 } 573 574 static void uniphier_spi_handle_err(struct spi_master *master, 575 struct spi_message *msg) 576 { 577 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 578 u32 val; 579 580 /* stop running spi transfer */ 581 writel(0, priv->base + SSI_CTL); 582 583 /* reset FIFOs */ 584 val = SSI_FC_TXFFL | SSI_FC_RXFFL; 585 writel(val, priv->base + SSI_FC); 586 587 uniphier_spi_irq_disable(priv, SSI_IE_ALL_MASK); 588 589 if (atomic_read(&priv->dma_busy) & SSI_DMA_TX_BUSY) { 590 dmaengine_terminate_async(master->dma_tx); 591 atomic_andnot(SSI_DMA_TX_BUSY, &priv->dma_busy); 592 } 593 594 if (atomic_read(&priv->dma_busy) & SSI_DMA_RX_BUSY) { 595 dmaengine_terminate_async(master->dma_rx); 596 atomic_andnot(SSI_DMA_RX_BUSY, &priv->dma_busy); 597 } 598 } 599 600 static irqreturn_t uniphier_spi_handler(int irq, void *dev_id) 601 { 602 struct uniphier_spi_priv *priv = dev_id; 603 u32 val, stat; 604 605 stat = readl(priv->base + SSI_IS); 606 val = SSI_IC_TCIC | SSI_IC_RCIC | SSI_IC_RORIC; 607 writel(val, priv->base + SSI_IC); 608 609 /* rx fifo overrun */ 610 if (stat & SSI_IS_RORID) { 611 priv->error = -EIO; 612 goto done; 613 } 614 615 /* rx complete */ 616 if ((stat & SSI_IS_RCID) && (stat & SSI_IS_RXRS)) { 617 while ((readl(priv->base + SSI_SR) & SSI_SR_RNE) && 618 (priv->rx_bytes - priv->tx_bytes) > 0) 619 uniphier_spi_recv(priv); 620 621 if ((readl(priv->base + SSI_SR) & SSI_SR_RNE) || 622 (priv->rx_bytes != priv->tx_bytes)) { 623 priv->error = -EIO; 624 goto done; 625 } else if (priv->rx_bytes == 0) 626 goto done; 627 628 /* next tx transfer */ 629 uniphier_spi_fill_tx_fifo(priv); 630 631 return IRQ_HANDLED; 632 } 633 634 return IRQ_NONE; 635 636 done: 637 complete(&priv->xfer_done); 638 return IRQ_HANDLED; 639 } 640 641 static int uniphier_spi_probe(struct platform_device *pdev) 642 { 643 struct uniphier_spi_priv *priv; 644 struct spi_master *master; 645 struct resource *res; 646 struct dma_slave_caps caps; 647 u32 dma_tx_burst = 0, dma_rx_burst = 0; 648 unsigned long clk_rate; 649 int irq; 650 int ret; 651 652 master = spi_alloc_master(&pdev->dev, sizeof(*priv)); 653 if (!master) 654 return -ENOMEM; 655 656 platform_set_drvdata(pdev, master); 657 658 priv = spi_master_get_devdata(master); 659 priv->master = master; 660 priv->is_save_param = false; 661 662 priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 663 if (IS_ERR(priv->base)) { 664 ret = PTR_ERR(priv->base); 665 goto out_master_put; 666 } 667 priv->base_dma_addr = res->start; 668 669 priv->clk = devm_clk_get(&pdev->dev, NULL); 670 if (IS_ERR(priv->clk)) { 671 dev_err(&pdev->dev, "failed to get clock\n"); 672 ret = PTR_ERR(priv->clk); 673 goto out_master_put; 674 } 675 676 ret = clk_prepare_enable(priv->clk); 677 if (ret) 678 goto out_master_put; 679 680 irq = platform_get_irq(pdev, 0); 681 if (irq < 0) { 682 ret = irq; 683 goto out_disable_clk; 684 } 685 686 ret = devm_request_irq(&pdev->dev, irq, uniphier_spi_handler, 687 0, "uniphier-spi", priv); 688 if (ret) { 689 dev_err(&pdev->dev, "failed to request IRQ\n"); 690 goto out_disable_clk; 691 } 692 693 init_completion(&priv->xfer_done); 694 695 clk_rate = clk_get_rate(priv->clk); 696 697 master->max_speed_hz = DIV_ROUND_UP(clk_rate, SSI_MIN_CLK_DIVIDER); 698 master->min_speed_hz = DIV_ROUND_UP(clk_rate, SSI_MAX_CLK_DIVIDER); 699 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST; 700 master->dev.of_node = pdev->dev.of_node; 701 master->bus_num = pdev->id; 702 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); 703 704 master->set_cs = uniphier_spi_set_cs; 705 master->transfer_one = uniphier_spi_transfer_one; 706 master->prepare_transfer_hardware 707 = uniphier_spi_prepare_transfer_hardware; 708 master->unprepare_transfer_hardware 709 = uniphier_spi_unprepare_transfer_hardware; 710 master->handle_err = uniphier_spi_handle_err; 711 master->can_dma = uniphier_spi_can_dma; 712 713 master->num_chipselect = 1; 714 master->flags = SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX; 715 716 master->dma_tx = dma_request_chan(&pdev->dev, "tx"); 717 if (IS_ERR_OR_NULL(master->dma_tx)) { 718 if (PTR_ERR(master->dma_tx) == -EPROBE_DEFER) { 719 ret = -EPROBE_DEFER; 720 goto out_disable_clk; 721 } 722 master->dma_tx = NULL; 723 dma_tx_burst = INT_MAX; 724 } else { 725 ret = dma_get_slave_caps(master->dma_tx, &caps); 726 if (ret) { 727 dev_err(&pdev->dev, "failed to get TX DMA capacities: %d\n", 728 ret); 729 goto out_release_dma; 730 } 731 dma_tx_burst = caps.max_burst; 732 } 733 734 master->dma_rx = dma_request_chan(&pdev->dev, "rx"); 735 if (IS_ERR_OR_NULL(master->dma_rx)) { 736 if (PTR_ERR(master->dma_rx) == -EPROBE_DEFER) { 737 ret = -EPROBE_DEFER; 738 goto out_release_dma; 739 } 740 master->dma_rx = NULL; 741 dma_rx_burst = INT_MAX; 742 } else { 743 ret = dma_get_slave_caps(master->dma_rx, &caps); 744 if (ret) { 745 dev_err(&pdev->dev, "failed to get RX DMA capacities: %d\n", 746 ret); 747 goto out_release_dma; 748 } 749 dma_rx_burst = caps.max_burst; 750 } 751 752 master->max_dma_len = min(dma_tx_burst, dma_rx_burst); 753 754 ret = devm_spi_register_master(&pdev->dev, master); 755 if (ret) 756 goto out_release_dma; 757 758 return 0; 759 760 out_release_dma: 761 if (!IS_ERR_OR_NULL(master->dma_rx)) { 762 dma_release_channel(master->dma_rx); 763 master->dma_rx = NULL; 764 } 765 if (!IS_ERR_OR_NULL(master->dma_tx)) { 766 dma_release_channel(master->dma_tx); 767 master->dma_tx = NULL; 768 } 769 770 out_disable_clk: 771 clk_disable_unprepare(priv->clk); 772 773 out_master_put: 774 spi_master_put(master); 775 return ret; 776 } 777 778 static int uniphier_spi_remove(struct platform_device *pdev) 779 { 780 struct spi_master *master = platform_get_drvdata(pdev); 781 struct uniphier_spi_priv *priv = spi_master_get_devdata(master); 782 783 if (master->dma_tx) 784 dma_release_channel(master->dma_tx); 785 if (master->dma_rx) 786 dma_release_channel(master->dma_rx); 787 788 clk_disable_unprepare(priv->clk); 789 790 return 0; 791 } 792 793 static const struct of_device_id uniphier_spi_match[] = { 794 { .compatible = "socionext,uniphier-scssi" }, 795 { /* sentinel */ } 796 }; 797 MODULE_DEVICE_TABLE(of, uniphier_spi_match); 798 799 static struct platform_driver uniphier_spi_driver = { 800 .probe = uniphier_spi_probe, 801 .remove = uniphier_spi_remove, 802 .driver = { 803 .name = "uniphier-spi", 804 .of_match_table = uniphier_spi_match, 805 }, 806 }; 807 module_platform_driver(uniphier_spi_driver); 808 809 MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>"); 810 MODULE_AUTHOR("Keiji Hayashibara <hayashibara.keiji@socionext.com>"); 811 MODULE_DESCRIPTION("Socionext UniPhier SPI controller driver"); 812 MODULE_LICENSE("GPL v2"); 813