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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 | /* * Cadence SPI controller driver (master mode only) * * Copyright (C) 2008 - 2014 Xilinx, Inc. * * based on Blackfin On-Chip SPI Driver (spi_bfin5xx.c) * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License version 2 as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. */ #include <linux/clk.h> #include <linux/delay.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of_irq.h> #include <linux/of_address.h> #include <linux/platform_device.h> #include <linux/spi/spi.h> /* Name of this driver */ #define CDNS_SPI_NAME "cdns-spi" /* Register offset definitions */ #define CDNS_SPI_CR_OFFSET 0x00 /* Configuration Register, RW */ #define CDNS_SPI_ISR_OFFSET 0x04 /* Interrupt Status Register, RO */ #define CDNS_SPI_IER_OFFSET 0x08 /* Interrupt Enable Register, WO */ #define CDNS_SPI_IDR_OFFSET 0x0c /* Interrupt Disable Register, WO */ #define CDNS_SPI_IMR_OFFSET 0x10 /* Interrupt Enabled Mask Register, RO */ #define CDNS_SPI_ER_OFFSET 0x14 /* Enable/Disable Register, RW */ #define CDNS_SPI_DR_OFFSET 0x18 /* Delay Register, RW */ #define CDNS_SPI_TXD_OFFSET 0x1C /* Data Transmit Register, WO */ #define CDNS_SPI_RXD_OFFSET 0x20 /* Data Receive Register, RO */ #define CDNS_SPI_SICR_OFFSET 0x24 /* Slave Idle Count Register, RW */ #define CDNS_SPI_THLD_OFFSET 0x28 /* Transmit FIFO Watermark Register,RW */ /* * SPI Configuration Register bit Masks * * This register contains various control bits that affect the operation * of the SPI controller */ #define CDNS_SPI_CR_MANSTRT_MASK 0x00010000 /* Manual TX Start */ #define CDNS_SPI_CR_CPHA_MASK 0x00000004 /* Clock Phase Control */ #define CDNS_SPI_CR_CPOL_MASK 0x00000002 /* Clock Polarity Control */ #define CDNS_SPI_CR_SSCTRL_MASK 0x00003C00 /* Slave Select Mask */ #define CDNS_SPI_CR_BAUD_DIV_MASK 0x00000038 /* Baud Rate Divisor Mask */ #define CDNS_SPI_CR_MSTREN_MASK 0x00000001 /* Master Enable Mask */ #define CDNS_SPI_CR_MANSTRTEN_MASK 0x00008000 /* Manual TX Enable Mask */ #define CDNS_SPI_CR_SSFORCE_MASK 0x00004000 /* Manual SS Enable Mask */ #define CDNS_SPI_CR_BAUD_DIV_4_MASK 0x00000008 /* Default Baud Div Mask */ #define CDNS_SPI_CR_DEFAULT_MASK (CDNS_SPI_CR_MSTREN_MASK | \ CDNS_SPI_CR_SSCTRL_MASK | \ CDNS_SPI_CR_SSFORCE_MASK | \ CDNS_SPI_CR_BAUD_DIV_4_MASK) /* * SPI Configuration Register - Baud rate and slave select * * These are the values used in the calculation of baud rate divisor and * setting the slave select. */ #define CDNS_SPI_BAUD_DIV_MAX 7 /* Baud rate divisor maximum */ #define CDNS_SPI_BAUD_DIV_MIN 1 /* Baud rate divisor minimum */ #define CDNS_SPI_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift in CR */ #define CDNS_SPI_SS_SHIFT 10 /* Slave Select field shift in CR */ #define CDNS_SPI_SS0 0x1 /* Slave Select zero */ /* * SPI Interrupt Registers bit Masks * * All the four interrupt registers (Status/Mask/Enable/Disable) have the same * bit definitions. */ #define CDNS_SPI_IXR_TXOW_MASK 0x00000004 /* SPI TX FIFO Overwater */ #define CDNS_SPI_IXR_MODF_MASK 0x00000002 /* SPI Mode Fault */ #define CDNS_SPI_IXR_RXNEMTY_MASK 0x00000010 /* SPI RX FIFO Not Empty */ #define CDNS_SPI_IXR_DEFAULT_MASK (CDNS_SPI_IXR_TXOW_MASK | \ CDNS_SPI_IXR_MODF_MASK) #define CDNS_SPI_IXR_TXFULL_MASK 0x00000008 /* SPI TX Full */ #define CDNS_SPI_IXR_ALL_MASK 0x0000007F /* SPI all interrupts */ /* * SPI Enable Register bit Masks * * This register is used to enable or disable the SPI controller */ #define CDNS_SPI_ER_ENABLE_MASK 0x00000001 /* SPI Enable Bit Mask */ #define CDNS_SPI_ER_DISABLE_MASK 0x0 /* SPI Disable Bit Mask */ /* SPI FIFO depth in bytes */ #define CDNS_SPI_FIFO_DEPTH 128 /* Default number of chip select lines */ #define CDNS_SPI_DEFAULT_NUM_CS 4 /** * struct cdns_spi - This definition defines spi driver instance * @regs: Virtual address of the SPI controller registers * @ref_clk: Pointer to the peripheral clock * @pclk: Pointer to the APB clock * @speed_hz: Current SPI bus clock speed in Hz * @txbuf: Pointer to the TX buffer * @rxbuf: Pointer to the RX buffer * @tx_bytes: Number of bytes left to transfer * @rx_bytes: Number of bytes requested * @dev_busy: Device busy flag * @is_decoded_cs: Flag for decoder property set or not */ struct cdns_spi { void __iomem *regs; struct clk *ref_clk; struct clk *pclk; u32 speed_hz; const u8 *txbuf; u8 *rxbuf; int tx_bytes; int rx_bytes; u8 dev_busy; u32 is_decoded_cs; }; /* Macros for the SPI controller read/write */ static inline u32 cdns_spi_read(struct cdns_spi *xspi, u32 offset) { return readl_relaxed(xspi->regs + offset); } static inline void cdns_spi_write(struct cdns_spi *xspi, u32 offset, u32 val) { writel_relaxed(val, xspi->regs + offset); } /** * cdns_spi_init_hw - Initialize the hardware and configure the SPI controller * @xspi: Pointer to the cdns_spi structure * * On reset the SPI controller is configured to be in master mode, baud rate * divisor is set to 4, threshold value for TX FIFO not full interrupt is set * to 1 and size of the word to be transferred as 8 bit. * This function initializes the SPI controller to disable and clear all the * interrupts, enable manual slave select and manual start, deselect all the * chip select lines, and enable the SPI controller. */ static void cdns_spi_init_hw(struct cdns_spi *xspi) { cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, CDNS_SPI_ER_DISABLE_MASK); cdns_spi_write(xspi, CDNS_SPI_IDR_OFFSET, CDNS_SPI_IXR_ALL_MASK); /* Clear the RX FIFO */ while (cdns_spi_read(xspi, CDNS_SPI_ISR_OFFSET) & CDNS_SPI_IXR_RXNEMTY_MASK) cdns_spi_read(xspi, CDNS_SPI_RXD_OFFSET); cdns_spi_write(xspi, CDNS_SPI_ISR_OFFSET, CDNS_SPI_IXR_ALL_MASK); cdns_spi_write(xspi, CDNS_SPI_CR_OFFSET, CDNS_SPI_CR_DEFAULT_MASK); cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, CDNS_SPI_ER_ENABLE_MASK); } /** * cdns_spi_chipselect - Select or deselect the chip select line * @spi: Pointer to the spi_device structure * @is_on: Select(0) or deselect (1) the chip select line */ static void cdns_spi_chipselect(struct spi_device *spi, bool is_high) { struct cdns_spi *xspi = spi_master_get_devdata(spi->master); u32 ctrl_reg; ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR_OFFSET); if (is_high) { /* Deselect the slave */ ctrl_reg |= CDNS_SPI_CR_SSCTRL_MASK; } else { /* Select the slave */ ctrl_reg &= ~CDNS_SPI_CR_SSCTRL_MASK; if (!(xspi->is_decoded_cs)) ctrl_reg |= ((~(CDNS_SPI_SS0 << spi->chip_select)) << CDNS_SPI_SS_SHIFT) & CDNS_SPI_CR_SSCTRL_MASK; else ctrl_reg |= (spi->chip_select << CDNS_SPI_SS_SHIFT) & CDNS_SPI_CR_SSCTRL_MASK; } cdns_spi_write(xspi, CDNS_SPI_CR_OFFSET, ctrl_reg); } /** * cdns_spi_config_clock_mode - Sets clock polarity and phase * @spi: Pointer to the spi_device structure * * Sets the requested clock polarity and phase. */ static void cdns_spi_config_clock_mode(struct spi_device *spi) { struct cdns_spi *xspi = spi_master_get_devdata(spi->master); u32 ctrl_reg; ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR_OFFSET); /* Set the SPI clock phase and clock polarity */ ctrl_reg &= ~(CDNS_SPI_CR_CPHA_MASK | CDNS_SPI_CR_CPOL_MASK); if (spi->mode & SPI_CPHA) ctrl_reg |= CDNS_SPI_CR_CPHA_MASK; if (spi->mode & SPI_CPOL) ctrl_reg |= CDNS_SPI_CR_CPOL_MASK; cdns_spi_write(xspi, CDNS_SPI_CR_OFFSET, ctrl_reg); } /** * cdns_spi_config_clock_freq - Sets clock frequency * @spi: Pointer to the spi_device structure * @transfer: Pointer to the spi_transfer structure which provides * information about next transfer setup parameters * * Sets the requested clock frequency. * Note: If the requested frequency is not an exact match with what can be * obtained using the prescalar value the driver sets the clock frequency which * is lower than the requested frequency (maximum lower) for the transfer. If * the requested frequency is higher or lower than that is supported by the SPI * controller the driver will set the highest or lowest frequency supported by * controller. */ static void cdns_spi_config_clock_freq(struct spi_device *spi, struct spi_transfer *transfer) { struct cdns_spi *xspi = spi_master_get_devdata(spi->master); u32 ctrl_reg, baud_rate_val; unsigned long frequency; frequency = clk_get_rate(xspi->ref_clk); ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR_OFFSET); /* Set the clock frequency */ if (xspi->speed_hz != transfer->speed_hz) { /* first valid value is 1 */ baud_rate_val = CDNS_SPI_BAUD_DIV_MIN; while ((baud_rate_val < CDNS_SPI_BAUD_DIV_MAX) && (frequency / (2 << baud_rate_val)) > transfer->speed_hz) baud_rate_val++; ctrl_reg &= ~CDNS_SPI_CR_BAUD_DIV_MASK; ctrl_reg |= baud_rate_val << CDNS_SPI_BAUD_DIV_SHIFT; xspi->speed_hz = frequency / (2 << baud_rate_val); } cdns_spi_write(xspi, CDNS_SPI_CR_OFFSET, ctrl_reg); } /** * cdns_spi_setup_transfer - Configure SPI controller for specified transfer * @spi: Pointer to the spi_device structure * @transfer: Pointer to the spi_transfer structure which provides * information about next transfer setup parameters * * Sets the operational mode of SPI controller for the next SPI transfer and * sets the requested clock frequency. * * Return: Always 0 */ static int cdns_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *transfer) { struct cdns_spi *xspi = spi_master_get_devdata(spi->master); cdns_spi_config_clock_freq(spi, transfer); dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u clock speed\n", __func__, spi->mode, spi->bits_per_word, xspi->speed_hz); return 0; } /** * cdns_spi_fill_tx_fifo - Fills the TX FIFO with as many bytes as possible * @xspi: Pointer to the cdns_spi structure */ static void cdns_spi_fill_tx_fifo(struct cdns_spi *xspi) { unsigned long trans_cnt = 0; while ((trans_cnt < CDNS_SPI_FIFO_DEPTH) && (xspi->tx_bytes > 0)) { if (xspi->txbuf) cdns_spi_write(xspi, CDNS_SPI_TXD_OFFSET, *xspi->txbuf++); else cdns_spi_write(xspi, CDNS_SPI_TXD_OFFSET, 0); xspi->tx_bytes--; trans_cnt++; } } /** * cdns_spi_irq - Interrupt service routine of the SPI controller * @irq: IRQ number * @dev_id: Pointer to the xspi structure * * This function handles TX empty and Mode Fault interrupts only. * On TX empty interrupt this function reads the received data from RX FIFO and * fills the TX FIFO if there is any data remaining to be transferred. * On Mode Fault interrupt this function indicates that transfer is completed, * the SPI subsystem will identify the error as the remaining bytes to be * transferred is non-zero. * * Return: IRQ_HANDLED when handled; IRQ_NONE otherwise. */ static irqreturn_t cdns_spi_irq(int irq, void *dev_id) { struct spi_master *master = dev_id; struct cdns_spi *xspi = spi_master_get_devdata(master); u32 intr_status, status; status = IRQ_NONE; intr_status = cdns_spi_read(xspi, CDNS_SPI_ISR_OFFSET); cdns_spi_write(xspi, CDNS_SPI_ISR_OFFSET, intr_status); if (intr_status & CDNS_SPI_IXR_MODF_MASK) { /* Indicate that transfer is completed, the SPI subsystem will * identify the error as the remaining bytes to be * transferred is non-zero */ cdns_spi_write(xspi, CDNS_SPI_IDR_OFFSET, CDNS_SPI_IXR_DEFAULT_MASK); spi_finalize_current_transfer(master); status = IRQ_HANDLED; } else if (intr_status & CDNS_SPI_IXR_TXOW_MASK) { unsigned long trans_cnt; trans_cnt = xspi->rx_bytes - xspi->tx_bytes; /* Read out the data from the RX FIFO */ while (trans_cnt) { u8 data; data = cdns_spi_read(xspi, CDNS_SPI_RXD_OFFSET); if (xspi->rxbuf) *xspi->rxbuf++ = data; xspi->rx_bytes--; trans_cnt--; } if (xspi->tx_bytes) { /* There is more data to send */ cdns_spi_fill_tx_fifo(xspi); } else { /* Transfer is completed */ cdns_spi_write(xspi, CDNS_SPI_IDR_OFFSET, CDNS_SPI_IXR_DEFAULT_MASK); spi_finalize_current_transfer(master); } status = IRQ_HANDLED; } return status; } /** * cdns_transfer_one - Initiates the SPI transfer * @master: Pointer to spi_master structure * @spi: Pointer to the spi_device structure * @transfer: Pointer to the spi_transfer structure which provides * information about next transfer parameters * * This function fills the TX FIFO, starts the SPI transfer and * returns a positive transfer count so that core will wait for completion. * * Return: Number of bytes transferred in the last transfer */ static int cdns_transfer_one(struct spi_master *master, struct spi_device *spi, struct spi_transfer *transfer) { struct cdns_spi *xspi = spi_master_get_devdata(master); xspi->txbuf = transfer->tx_buf; xspi->rxbuf = transfer->rx_buf; xspi->tx_bytes = transfer->len; xspi->rx_bytes = transfer->len; cdns_spi_setup_transfer(spi, transfer); cdns_spi_fill_tx_fifo(xspi); cdns_spi_write(xspi, CDNS_SPI_IER_OFFSET, CDNS_SPI_IXR_DEFAULT_MASK); return transfer->len; } /** * cdns_prepare_transfer_hardware - Prepares hardware for transfer. * @master: Pointer to the spi_master structure which provides * information about the controller. * * This function enables SPI master controller. * * Return: 0 always */ static int cdns_prepare_transfer_hardware(struct spi_master *master) { struct cdns_spi *xspi = spi_master_get_devdata(master); cdns_spi_config_clock_mode(master->cur_msg->spi); cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, CDNS_SPI_ER_ENABLE_MASK); return 0; } /** * cdns_unprepare_transfer_hardware - Relaxes hardware after transfer * @master: Pointer to the spi_master structure which provides * information about the controller. * * This function disables the SPI master controller. * * Return: 0 always */ static int cdns_unprepare_transfer_hardware(struct spi_master *master) { struct cdns_spi *xspi = spi_master_get_devdata(master); cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, CDNS_SPI_ER_DISABLE_MASK); return 0; } /** * cdns_spi_probe - Probe method for the SPI driver * @pdev: Pointer to the platform_device structure * * This function initializes the driver data structures and the hardware. * * Return: 0 on success and error value on error */ static int cdns_spi_probe(struct platform_device *pdev) { int ret = 0, irq; struct spi_master *master; struct cdns_spi *xspi; struct resource *res; u32 num_cs; master = spi_alloc_master(&pdev->dev, sizeof(*xspi)); if (master == NULL) return -ENOMEM; xspi = spi_master_get_devdata(master); master->dev.of_node = pdev->dev.of_node; platform_set_drvdata(pdev, master); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); xspi->regs = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(xspi->regs)) { ret = PTR_ERR(xspi->regs); goto remove_master; } xspi->pclk = devm_clk_get(&pdev->dev, "pclk"); if (IS_ERR(xspi->pclk)) { dev_err(&pdev->dev, "pclk clock not found.\n"); ret = PTR_ERR(xspi->pclk); goto remove_master; } xspi->ref_clk = devm_clk_get(&pdev->dev, "ref_clk"); if (IS_ERR(xspi->ref_clk)) { dev_err(&pdev->dev, "ref_clk clock not found.\n"); ret = PTR_ERR(xspi->ref_clk); goto remove_master; } ret = clk_prepare_enable(xspi->pclk); if (ret) { dev_err(&pdev->dev, "Unable to enable APB clock.\n"); goto remove_master; } ret = clk_prepare_enable(xspi->ref_clk); if (ret) { dev_err(&pdev->dev, "Unable to enable device clock.\n"); goto clk_dis_apb; } /* SPI controller initializations */ cdns_spi_init_hw(xspi); irq = platform_get_irq(pdev, 0); if (irq <= 0) { ret = -ENXIO; dev_err(&pdev->dev, "irq number is invalid\n"); goto remove_master; } ret = devm_request_irq(&pdev->dev, irq, cdns_spi_irq, 0, pdev->name, master); if (ret != 0) { ret = -ENXIO; dev_err(&pdev->dev, "request_irq failed\n"); goto remove_master; } ret = of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs); if (ret < 0) master->num_chipselect = CDNS_SPI_DEFAULT_NUM_CS; else master->num_chipselect = num_cs; ret = of_property_read_u32(pdev->dev.of_node, "is-decoded-cs", &xspi->is_decoded_cs); if (ret < 0) xspi->is_decoded_cs = 0; master->prepare_transfer_hardware = cdns_prepare_transfer_hardware; master->transfer_one = cdns_transfer_one; master->unprepare_transfer_hardware = cdns_unprepare_transfer_hardware; master->set_cs = cdns_spi_chipselect; master->mode_bits = SPI_CPOL | SPI_CPHA; /* Set to default valid value */ master->max_speed_hz = clk_get_rate(xspi->ref_clk) / 4; xspi->speed_hz = master->max_speed_hz; master->bits_per_word_mask = SPI_BPW_MASK(8); ret = spi_register_master(master); if (ret) { dev_err(&pdev->dev, "spi_register_master failed\n"); goto clk_dis_all; } return ret; clk_dis_all: clk_disable_unprepare(xspi->ref_clk); clk_dis_apb: clk_disable_unprepare(xspi->pclk); remove_master: spi_master_put(master); return ret; } /** * cdns_spi_remove - Remove method for the SPI driver * @pdev: Pointer to the platform_device structure * * This function is called if a device is physically removed from the system or * if the driver module is being unloaded. It frees all resources allocated to * the device. * * Return: 0 on success and error value on error */ static int cdns_spi_remove(struct platform_device *pdev) { struct spi_master *master = platform_get_drvdata(pdev); struct cdns_spi *xspi = spi_master_get_devdata(master); cdns_spi_write(xspi, CDNS_SPI_ER_OFFSET, CDNS_SPI_ER_DISABLE_MASK); clk_disable_unprepare(xspi->ref_clk); clk_disable_unprepare(xspi->pclk); spi_unregister_master(master); return 0; } /** * cdns_spi_suspend - Suspend method for the SPI driver * @dev: Address of the platform_device structure * * This function disables the SPI controller and * changes the driver state to "suspend" * * Return: Always 0 */ static int __maybe_unused cdns_spi_suspend(struct device *dev) { struct platform_device *pdev = container_of(dev, struct platform_device, dev); struct spi_master *master = platform_get_drvdata(pdev); struct cdns_spi *xspi = spi_master_get_devdata(master); spi_master_suspend(master); clk_disable_unprepare(xspi->ref_clk); clk_disable_unprepare(xspi->pclk); return 0; } /** * cdns_spi_resume - Resume method for the SPI driver * @dev: Address of the platform_device structure * * This function changes the driver state to "ready" * * Return: 0 on success and error value on error */ static int __maybe_unused cdns_spi_resume(struct device *dev) { struct platform_device *pdev = container_of(dev, struct platform_device, dev); struct spi_master *master = platform_get_drvdata(pdev); struct cdns_spi *xspi = spi_master_get_devdata(master); int ret = 0; ret = clk_prepare_enable(xspi->pclk); if (ret) { dev_err(dev, "Cannot enable APB clock.\n"); return ret; } ret = clk_prepare_enable(xspi->ref_clk); if (ret) { dev_err(dev, "Cannot enable device clock.\n"); clk_disable(xspi->pclk); return ret; } spi_master_resume(master); return 0; } static SIMPLE_DEV_PM_OPS(cdns_spi_dev_pm_ops, cdns_spi_suspend, cdns_spi_resume); static struct of_device_id cdns_spi_of_match[] = { { .compatible = "xlnx,zynq-spi-r1p6" }, { .compatible = "cdns,spi-r1p6" }, { /* end of table */ } }; MODULE_DEVICE_TABLE(of, cdns_spi_of_match); /* cdns_spi_driver - This structure defines the SPI subsystem platform driver */ static struct platform_driver cdns_spi_driver = { .probe = cdns_spi_probe, .remove = cdns_spi_remove, .driver = { .name = CDNS_SPI_NAME, .owner = THIS_MODULE, .of_match_table = cdns_spi_of_match, .pm = &cdns_spi_dev_pm_ops, }, }; module_platform_driver(cdns_spi_driver); MODULE_AUTHOR("Xilinx, Inc."); MODULE_DESCRIPTION("Cadence SPI driver"); MODULE_LICENSE("GPL"); |