1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Cadence SPI controller driver (host and target mode) 4 * 5 * Copyright (C) 2008 - 2014 Xilinx, Inc. 6 * 7 * based on Blackfin On-Chip SPI Driver (spi_bfin5xx.c) 8 */ 9 10 #include <linux/clk.h> 11 #include <linux/delay.h> 12 #include <linux/gpio/consumer.h> 13 #include <linux/interrupt.h> 14 #include <linux/io.h> 15 #include <linux/kernel.h> 16 #include <linux/module.h> 17 #include <linux/of_irq.h> 18 #include <linux/of_address.h> 19 #include <linux/platform_device.h> 20 #include <linux/pm_runtime.h> 21 #include <linux/spi/spi.h> 22 23 /* Name of this driver */ 24 #define CDNS_SPI_NAME "cdns-spi" 25 26 /* Register offset definitions */ 27 #define CDNS_SPI_CR 0x00 /* Configuration Register, RW */ 28 #define CDNS_SPI_ISR 0x04 /* Interrupt Status Register, RO */ 29 #define CDNS_SPI_IER 0x08 /* Interrupt Enable Register, WO */ 30 #define CDNS_SPI_IDR 0x0c /* Interrupt Disable Register, WO */ 31 #define CDNS_SPI_IMR 0x10 /* Interrupt Enabled Mask Register, RO */ 32 #define CDNS_SPI_ER 0x14 /* Enable/Disable Register, RW */ 33 #define CDNS_SPI_DR 0x18 /* Delay Register, RW */ 34 #define CDNS_SPI_TXD 0x1C /* Data Transmit Register, WO */ 35 #define CDNS_SPI_RXD 0x20 /* Data Receive Register, RO */ 36 #define CDNS_SPI_SICR 0x24 /* Slave Idle Count Register, RW */ 37 #define CDNS_SPI_THLD 0x28 /* Transmit FIFO Watermark Register,RW */ 38 39 #define SPI_AUTOSUSPEND_TIMEOUT 3000 40 /* 41 * SPI Configuration Register bit Masks 42 * 43 * This register contains various control bits that affect the operation 44 * of the SPI controller 45 */ 46 #define CDNS_SPI_CR_MANSTRT 0x00010000 /* Manual TX Start */ 47 #define CDNS_SPI_CR_CPHA 0x00000004 /* Clock Phase Control */ 48 #define CDNS_SPI_CR_CPOL 0x00000002 /* Clock Polarity Control */ 49 #define CDNS_SPI_CR_SSCTRL 0x00003C00 /* Slave Select Mask */ 50 #define CDNS_SPI_CR_PERI_SEL 0x00000200 /* Peripheral Select Decode */ 51 #define CDNS_SPI_CR_BAUD_DIV 0x00000038 /* Baud Rate Divisor Mask */ 52 #define CDNS_SPI_CR_MSTREN 0x00000001 /* Master Enable Mask */ 53 #define CDNS_SPI_CR_MANSTRTEN 0x00008000 /* Manual TX Enable Mask */ 54 #define CDNS_SPI_CR_SSFORCE 0x00004000 /* Manual SS Enable Mask */ 55 #define CDNS_SPI_CR_BAUD_DIV_4 0x00000008 /* Default Baud Div Mask */ 56 #define CDNS_SPI_CR_DEFAULT (CDNS_SPI_CR_MSTREN | \ 57 CDNS_SPI_CR_SSCTRL | \ 58 CDNS_SPI_CR_SSFORCE | \ 59 CDNS_SPI_CR_BAUD_DIV_4) 60 61 /* 62 * SPI Configuration Register - Baud rate and target select 63 * 64 * These are the values used in the calculation of baud rate divisor and 65 * setting the target select. 66 */ 67 68 #define CDNS_SPI_BAUD_DIV_MAX 7 /* Baud rate divisor maximum */ 69 #define CDNS_SPI_BAUD_DIV_MIN 1 /* Baud rate divisor minimum */ 70 #define CDNS_SPI_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift in CR */ 71 #define CDNS_SPI_SS_SHIFT 10 /* Slave Select field shift in CR */ 72 #define CDNS_SPI_SS0 0x1 /* Slave Select zero */ 73 #define CDNS_SPI_NOSS 0xF /* No Slave select */ 74 75 /* 76 * SPI Interrupt Registers bit Masks 77 * 78 * All the four interrupt registers (Status/Mask/Enable/Disable) have the same 79 * bit definitions. 80 */ 81 #define CDNS_SPI_IXR_TXOW 0x00000004 /* SPI TX FIFO Overwater */ 82 #define CDNS_SPI_IXR_MODF 0x00000002 /* SPI Mode Fault */ 83 #define CDNS_SPI_IXR_RXNEMTY 0x00000010 /* SPI RX FIFO Not Empty */ 84 #define CDNS_SPI_IXR_DEFAULT (CDNS_SPI_IXR_TXOW | \ 85 CDNS_SPI_IXR_MODF) 86 #define CDNS_SPI_IXR_TXFULL 0x00000008 /* SPI TX Full */ 87 #define CDNS_SPI_IXR_ALL 0x0000007F /* SPI all interrupts */ 88 89 /* 90 * SPI Enable Register bit Masks 91 * 92 * This register is used to enable or disable the SPI controller 93 */ 94 #define CDNS_SPI_ER_ENABLE 0x00000001 /* SPI Enable Bit Mask */ 95 #define CDNS_SPI_ER_DISABLE 0x0 /* SPI Disable Bit Mask */ 96 97 /* Default number of chip select lines */ 98 #define CDNS_SPI_DEFAULT_NUM_CS 4 99 100 /** 101 * struct cdns_spi - This definition defines spi driver instance 102 * @regs: Virtual address of the SPI controller registers 103 * @ref_clk: Pointer to the peripheral clock 104 * @pclk: Pointer to the APB clock 105 * @clk_rate: Reference clock frequency, taken from @ref_clk 106 * @speed_hz: Current SPI bus clock speed in Hz 107 * @txbuf: Pointer to the TX buffer 108 * @rxbuf: Pointer to the RX buffer 109 * @tx_bytes: Number of bytes left to transfer 110 * @rx_bytes: Number of bytes requested 111 * @dev_busy: Device busy flag 112 * @is_decoded_cs: Flag for decoder property set or not 113 * @tx_fifo_depth: Depth of the TX FIFO 114 */ 115 struct cdns_spi { 116 void __iomem *regs; 117 struct clk *ref_clk; 118 struct clk *pclk; 119 unsigned int clk_rate; 120 u32 speed_hz; 121 const u8 *txbuf; 122 u8 *rxbuf; 123 int tx_bytes; 124 int rx_bytes; 125 u8 dev_busy; 126 u32 is_decoded_cs; 127 unsigned int tx_fifo_depth; 128 }; 129 130 /* Macros for the SPI controller read/write */ 131 static inline u32 cdns_spi_read(struct cdns_spi *xspi, u32 offset) 132 { 133 return readl_relaxed(xspi->regs + offset); 134 } 135 136 static inline void cdns_spi_write(struct cdns_spi *xspi, u32 offset, u32 val) 137 { 138 writel_relaxed(val, xspi->regs + offset); 139 } 140 141 /** 142 * cdns_spi_init_hw - Initialize the hardware and configure the SPI controller 143 * @xspi: Pointer to the cdns_spi structure 144 * @is_target: Flag to indicate target or host mode 145 * * On reset the SPI controller is configured to target or host mode. 146 * In host mode baud rate divisor is set to 4, threshold value for TX FIFO 147 * not full interrupt is set to 1 and size of the word to be transferred as 8 bit. 148 * 149 * This function initializes the SPI controller to disable and clear all the 150 * interrupts, enable manual target select and manual start, deselect all the 151 * chip select lines, and enable the SPI controller. 152 */ 153 static void cdns_spi_init_hw(struct cdns_spi *xspi, bool is_target) 154 { 155 u32 ctrl_reg = 0; 156 157 if (!is_target) 158 ctrl_reg |= CDNS_SPI_CR_DEFAULT; 159 160 if (xspi->is_decoded_cs) 161 ctrl_reg |= CDNS_SPI_CR_PERI_SEL; 162 163 cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); 164 cdns_spi_write(xspi, CDNS_SPI_IDR, CDNS_SPI_IXR_ALL); 165 166 /* Clear the RX FIFO */ 167 while (cdns_spi_read(xspi, CDNS_SPI_ISR) & CDNS_SPI_IXR_RXNEMTY) 168 cdns_spi_read(xspi, CDNS_SPI_RXD); 169 170 cdns_spi_write(xspi, CDNS_SPI_ISR, CDNS_SPI_IXR_ALL); 171 cdns_spi_write(xspi, CDNS_SPI_CR, ctrl_reg); 172 cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_ENABLE); 173 } 174 175 /** 176 * cdns_spi_chipselect - Select or deselect the chip select line 177 * @spi: Pointer to the spi_device structure 178 * @is_high: Select(0) or deselect (1) the chip select line 179 */ 180 static void cdns_spi_chipselect(struct spi_device *spi, bool is_high) 181 { 182 struct cdns_spi *xspi = spi_controller_get_devdata(spi->controller); 183 u32 ctrl_reg; 184 185 ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR); 186 187 if (is_high) { 188 /* Deselect the target */ 189 ctrl_reg |= CDNS_SPI_CR_SSCTRL; 190 } else { 191 /* Select the target */ 192 ctrl_reg &= ~CDNS_SPI_CR_SSCTRL; 193 if (!(xspi->is_decoded_cs)) 194 ctrl_reg |= ((~(CDNS_SPI_SS0 << spi_get_chipselect(spi, 0))) << 195 CDNS_SPI_SS_SHIFT) & 196 CDNS_SPI_CR_SSCTRL; 197 else 198 ctrl_reg |= (spi_get_chipselect(spi, 0) << CDNS_SPI_SS_SHIFT) & 199 CDNS_SPI_CR_SSCTRL; 200 } 201 202 cdns_spi_write(xspi, CDNS_SPI_CR, ctrl_reg); 203 } 204 205 /** 206 * cdns_spi_config_clock_mode - Sets clock polarity and phase 207 * @spi: Pointer to the spi_device structure 208 * 209 * Sets the requested clock polarity and phase. 210 */ 211 static void cdns_spi_config_clock_mode(struct spi_device *spi) 212 { 213 struct cdns_spi *xspi = spi_controller_get_devdata(spi->controller); 214 u32 ctrl_reg, new_ctrl_reg; 215 216 new_ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR); 217 ctrl_reg = new_ctrl_reg; 218 219 /* Set the SPI clock phase and clock polarity */ 220 new_ctrl_reg &= ~(CDNS_SPI_CR_CPHA | CDNS_SPI_CR_CPOL); 221 if (spi->mode & SPI_CPHA) 222 new_ctrl_reg |= CDNS_SPI_CR_CPHA; 223 if (spi->mode & SPI_CPOL) 224 new_ctrl_reg |= CDNS_SPI_CR_CPOL; 225 226 if (new_ctrl_reg != ctrl_reg) { 227 /* 228 * Just writing the CR register does not seem to apply the clock 229 * setting changes. This is problematic when changing the clock 230 * polarity as it will cause the SPI target to see spurious clock 231 * transitions. To workaround the issue toggle the ER register. 232 */ 233 cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); 234 cdns_spi_write(xspi, CDNS_SPI_CR, new_ctrl_reg); 235 cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_ENABLE); 236 } 237 } 238 239 /** 240 * cdns_spi_config_clock_freq - Sets clock frequency 241 * @spi: Pointer to the spi_device structure 242 * @transfer: Pointer to the spi_transfer structure which provides 243 * information about next transfer setup parameters 244 * 245 * Sets the requested clock frequency. 246 * Note: If the requested frequency is not an exact match with what can be 247 * obtained using the prescalar value the driver sets the clock frequency which 248 * is lower than the requested frequency (maximum lower) for the transfer. If 249 * the requested frequency is higher or lower than that is supported by the SPI 250 * controller the driver will set the highest or lowest frequency supported by 251 * controller. 252 */ 253 static void cdns_spi_config_clock_freq(struct spi_device *spi, 254 struct spi_transfer *transfer) 255 { 256 struct cdns_spi *xspi = spi_controller_get_devdata(spi->controller); 257 u32 ctrl_reg, baud_rate_val; 258 unsigned long frequency; 259 260 frequency = xspi->clk_rate; 261 262 ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR); 263 264 /* Set the clock frequency */ 265 if (xspi->speed_hz != transfer->speed_hz) { 266 /* first valid value is 1 */ 267 baud_rate_val = CDNS_SPI_BAUD_DIV_MIN; 268 while ((baud_rate_val < CDNS_SPI_BAUD_DIV_MAX) && 269 (frequency / (2 << baud_rate_val)) > transfer->speed_hz) 270 baud_rate_val++; 271 272 ctrl_reg &= ~CDNS_SPI_CR_BAUD_DIV; 273 ctrl_reg |= baud_rate_val << CDNS_SPI_BAUD_DIV_SHIFT; 274 275 xspi->speed_hz = frequency / (2 << baud_rate_val); 276 } 277 cdns_spi_write(xspi, CDNS_SPI_CR, ctrl_reg); 278 } 279 280 /** 281 * cdns_spi_setup_transfer - Configure SPI controller for specified transfer 282 * @spi: Pointer to the spi_device structure 283 * @transfer: Pointer to the spi_transfer structure which provides 284 * information about next transfer setup parameters 285 * 286 * Sets the operational mode of SPI controller for the next SPI transfer and 287 * sets the requested clock frequency. 288 * 289 * Return: Always 0 290 */ 291 static int cdns_spi_setup_transfer(struct spi_device *spi, 292 struct spi_transfer *transfer) 293 { 294 struct cdns_spi *xspi = spi_controller_get_devdata(spi->controller); 295 296 cdns_spi_config_clock_freq(spi, transfer); 297 298 dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u clock speed\n", 299 __func__, spi->mode, spi->bits_per_word, 300 xspi->speed_hz); 301 302 return 0; 303 } 304 305 /** 306 * cdns_spi_process_fifo - Fills the TX FIFO, and drain the RX FIFO 307 * @xspi: Pointer to the cdns_spi structure 308 * @ntx: Number of bytes to pack into the TX FIFO 309 * @nrx: Number of bytes to drain from the RX FIFO 310 */ 311 static void cdns_spi_process_fifo(struct cdns_spi *xspi, int ntx, int nrx) 312 { 313 ntx = clamp(ntx, 0, xspi->tx_bytes); 314 nrx = clamp(nrx, 0, xspi->rx_bytes); 315 316 xspi->tx_bytes -= ntx; 317 xspi->rx_bytes -= nrx; 318 319 while (ntx || nrx) { 320 if (ntx) { 321 if (xspi->txbuf) 322 cdns_spi_write(xspi, CDNS_SPI_TXD, *xspi->txbuf++); 323 else 324 cdns_spi_write(xspi, CDNS_SPI_TXD, 0); 325 326 ntx--; 327 } 328 329 if (nrx) { 330 u8 data = cdns_spi_read(xspi, CDNS_SPI_RXD); 331 332 if (xspi->rxbuf) 333 *xspi->rxbuf++ = data; 334 335 nrx--; 336 } 337 } 338 } 339 340 /** 341 * cdns_spi_irq - Interrupt service routine of the SPI controller 342 * @irq: IRQ number 343 * @dev_id: Pointer to the xspi structure 344 * 345 * This function handles TX empty and Mode Fault interrupts only. 346 * On TX empty interrupt this function reads the received data from RX FIFO and 347 * fills the TX FIFO if there is any data remaining to be transferred. 348 * On Mode Fault interrupt this function indicates that transfer is completed, 349 * the SPI subsystem will identify the error as the remaining bytes to be 350 * transferred is non-zero. 351 * 352 * Return: IRQ_HANDLED when handled; IRQ_NONE otherwise. 353 */ 354 static irqreturn_t cdns_spi_irq(int irq, void *dev_id) 355 { 356 struct spi_controller *ctlr = dev_id; 357 struct cdns_spi *xspi = spi_controller_get_devdata(ctlr); 358 irqreturn_t status; 359 u32 intr_status; 360 361 status = IRQ_NONE; 362 intr_status = cdns_spi_read(xspi, CDNS_SPI_ISR); 363 cdns_spi_write(xspi, CDNS_SPI_ISR, intr_status); 364 365 if (intr_status & CDNS_SPI_IXR_MODF) { 366 /* Indicate that transfer is completed, the SPI subsystem will 367 * identify the error as the remaining bytes to be 368 * transferred is non-zero 369 */ 370 cdns_spi_write(xspi, CDNS_SPI_IDR, CDNS_SPI_IXR_DEFAULT); 371 spi_finalize_current_transfer(ctlr); 372 status = IRQ_HANDLED; 373 } else if (intr_status & CDNS_SPI_IXR_TXOW) { 374 int threshold = cdns_spi_read(xspi, CDNS_SPI_THLD); 375 int trans_cnt = xspi->rx_bytes - xspi->tx_bytes; 376 377 if (threshold > 1) 378 trans_cnt -= threshold; 379 380 /* Set threshold to one if number of pending are 381 * less than half fifo 382 */ 383 if (xspi->tx_bytes < xspi->tx_fifo_depth >> 1) 384 cdns_spi_write(xspi, CDNS_SPI_THLD, 1); 385 386 if (xspi->tx_bytes) { 387 cdns_spi_process_fifo(xspi, trans_cnt, trans_cnt); 388 } else { 389 /* Fixed delay due to controller limitation with 390 * RX_NEMPTY incorrect status 391 * Xilinx AR:65885 contains more details 392 */ 393 udelay(10); 394 cdns_spi_process_fifo(xspi, 0, trans_cnt); 395 cdns_spi_write(xspi, CDNS_SPI_IDR, 396 CDNS_SPI_IXR_DEFAULT); 397 spi_finalize_current_transfer(ctlr); 398 } 399 status = IRQ_HANDLED; 400 } 401 402 return status; 403 } 404 405 static int cdns_prepare_message(struct spi_controller *ctlr, 406 struct spi_message *msg) 407 { 408 if (!spi_controller_is_target(ctlr)) 409 cdns_spi_config_clock_mode(msg->spi); 410 return 0; 411 } 412 413 /** 414 * cdns_transfer_one - Initiates the SPI transfer 415 * @ctlr: Pointer to spi_controller structure 416 * @spi: Pointer to the spi_device structure 417 * @transfer: Pointer to the spi_transfer structure which provides 418 * information about next transfer parameters 419 * 420 * This function in host mode fills the TX FIFO, starts the SPI transfer and 421 * returns a positive transfer count so that core will wait for completion. 422 * This function in target mode fills the TX FIFO and wait for transfer trigger. 423 * 424 * Return: Number of bytes transferred in the last transfer 425 */ 426 static int cdns_transfer_one(struct spi_controller *ctlr, 427 struct spi_device *spi, 428 struct spi_transfer *transfer) 429 { 430 struct cdns_spi *xspi = spi_controller_get_devdata(ctlr); 431 432 xspi->txbuf = transfer->tx_buf; 433 xspi->rxbuf = transfer->rx_buf; 434 xspi->tx_bytes = transfer->len; 435 xspi->rx_bytes = transfer->len; 436 437 if (!spi_controller_is_target(ctlr)) { 438 cdns_spi_setup_transfer(spi, transfer); 439 } else { 440 /* Set TX empty threshold to half of FIFO depth 441 * only if TX bytes are more than FIFO depth. 442 */ 443 if (xspi->tx_bytes > xspi->tx_fifo_depth) 444 cdns_spi_write(xspi, CDNS_SPI_THLD, xspi->tx_fifo_depth >> 1); 445 } 446 447 /* When xspi in busy condition, bytes may send failed, 448 * then spi control didn't work thoroughly, add one byte delay 449 */ 450 if (cdns_spi_read(xspi, CDNS_SPI_ISR) & CDNS_SPI_IXR_TXFULL) 451 udelay(10); 452 453 cdns_spi_process_fifo(xspi, xspi->tx_fifo_depth, 0); 454 spi_transfer_delay_exec(transfer); 455 456 cdns_spi_write(xspi, CDNS_SPI_IER, CDNS_SPI_IXR_DEFAULT); 457 return transfer->len; 458 } 459 460 /** 461 * cdns_prepare_transfer_hardware - Prepares hardware for transfer. 462 * @ctlr: Pointer to the spi_controller structure which provides 463 * information about the controller. 464 * 465 * This function enables SPI host controller. 466 * 467 * Return: 0 always 468 */ 469 static int cdns_prepare_transfer_hardware(struct spi_controller *ctlr) 470 { 471 struct cdns_spi *xspi = spi_controller_get_devdata(ctlr); 472 473 cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_ENABLE); 474 475 return 0; 476 } 477 478 /** 479 * cdns_unprepare_transfer_hardware - Relaxes hardware after transfer 480 * @ctlr: Pointer to the spi_controller structure which provides 481 * information about the controller. 482 * 483 * This function disables the SPI host controller when no target selected. 484 * This function flush out if any pending data in FIFO. 485 * 486 * Return: 0 always 487 */ 488 static int cdns_unprepare_transfer_hardware(struct spi_controller *ctlr) 489 { 490 struct cdns_spi *xspi = spi_controller_get_devdata(ctlr); 491 u32 ctrl_reg; 492 unsigned int cnt = xspi->tx_fifo_depth; 493 494 if (spi_controller_is_target(ctlr)) { 495 while (cnt--) 496 cdns_spi_read(xspi, CDNS_SPI_RXD); 497 } 498 499 /* Disable the SPI if target is deselected */ 500 ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR); 501 ctrl_reg = (ctrl_reg & CDNS_SPI_CR_SSCTRL) >> CDNS_SPI_SS_SHIFT; 502 if (ctrl_reg == CDNS_SPI_NOSS || spi_controller_is_target(ctlr)) 503 cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); 504 505 /* Reset to default */ 506 cdns_spi_write(xspi, CDNS_SPI_THLD, 0x1); 507 return 0; 508 } 509 510 /** 511 * cdns_spi_detect_fifo_depth - Detect the FIFO depth of the hardware 512 * @xspi: Pointer to the cdns_spi structure 513 * 514 * The depth of the TX FIFO is a synthesis configuration parameter of the SPI 515 * IP. The FIFO threshold register is sized so that its maximum value can be the 516 * FIFO size - 1. This is used to detect the size of the FIFO. 517 */ 518 static void cdns_spi_detect_fifo_depth(struct cdns_spi *xspi) 519 { 520 /* The MSBs will get truncated giving us the size of the FIFO */ 521 cdns_spi_write(xspi, CDNS_SPI_THLD, 0xffff); 522 xspi->tx_fifo_depth = cdns_spi_read(xspi, CDNS_SPI_THLD) + 1; 523 524 /* Reset to default */ 525 cdns_spi_write(xspi, CDNS_SPI_THLD, 0x1); 526 } 527 528 /** 529 * cdns_target_abort - Abort target transfer 530 * @ctlr: Pointer to the spi_controller structure 531 * 532 * This function abort target transfer if there any transfer timeout. 533 * 534 * Return: 0 always 535 */ 536 static int cdns_target_abort(struct spi_controller *ctlr) 537 { 538 struct cdns_spi *xspi = spi_controller_get_devdata(ctlr); 539 u32 intr_status; 540 541 intr_status = cdns_spi_read(xspi, CDNS_SPI_ISR); 542 cdns_spi_write(xspi, CDNS_SPI_ISR, intr_status); 543 cdns_spi_write(xspi, CDNS_SPI_IDR, (CDNS_SPI_IXR_MODF | CDNS_SPI_IXR_RXNEMTY)); 544 spi_finalize_current_transfer(ctlr); 545 546 return 0; 547 } 548 549 /** 550 * cdns_spi_probe - Probe method for the SPI driver 551 * @pdev: Pointer to the platform_device structure 552 * 553 * This function initializes the driver data structures and the hardware. 554 * 555 * Return: 0 on success and error value on error 556 */ 557 static int cdns_spi_probe(struct platform_device *pdev) 558 { 559 int ret = 0, irq; 560 struct spi_controller *ctlr; 561 struct cdns_spi *xspi; 562 u32 num_cs; 563 bool target; 564 565 target = of_property_read_bool(pdev->dev.of_node, "spi-slave"); 566 if (target) 567 ctlr = spi_alloc_target(&pdev->dev, sizeof(*xspi)); 568 else 569 ctlr = spi_alloc_host(&pdev->dev, sizeof(*xspi)); 570 571 if (!ctlr) 572 return -ENOMEM; 573 574 xspi = spi_controller_get_devdata(ctlr); 575 ctlr->dev.of_node = pdev->dev.of_node; 576 platform_set_drvdata(pdev, ctlr); 577 578 xspi->regs = devm_platform_ioremap_resource(pdev, 0); 579 if (IS_ERR(xspi->regs)) { 580 ret = PTR_ERR(xspi->regs); 581 goto remove_ctlr; 582 } 583 584 xspi->pclk = devm_clk_get(&pdev->dev, "pclk"); 585 if (IS_ERR(xspi->pclk)) { 586 dev_err(&pdev->dev, "pclk clock not found.\n"); 587 ret = PTR_ERR(xspi->pclk); 588 goto remove_ctlr; 589 } 590 591 ret = clk_prepare_enable(xspi->pclk); 592 if (ret) { 593 dev_err(&pdev->dev, "Unable to enable APB clock.\n"); 594 goto remove_ctlr; 595 } 596 597 if (!spi_controller_is_target(ctlr)) { 598 xspi->ref_clk = devm_clk_get(&pdev->dev, "ref_clk"); 599 if (IS_ERR(xspi->ref_clk)) { 600 dev_err(&pdev->dev, "ref_clk clock not found.\n"); 601 ret = PTR_ERR(xspi->ref_clk); 602 goto clk_dis_apb; 603 } 604 605 ret = clk_prepare_enable(xspi->ref_clk); 606 if (ret) { 607 dev_err(&pdev->dev, "Unable to enable device clock.\n"); 608 goto clk_dis_apb; 609 } 610 611 pm_runtime_use_autosuspend(&pdev->dev); 612 pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT); 613 pm_runtime_get_noresume(&pdev->dev); 614 pm_runtime_set_active(&pdev->dev); 615 pm_runtime_enable(&pdev->dev); 616 617 ret = of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs); 618 if (ret < 0) 619 ctlr->num_chipselect = CDNS_SPI_DEFAULT_NUM_CS; 620 else 621 ctlr->num_chipselect = num_cs; 622 623 ret = of_property_read_u32(pdev->dev.of_node, "is-decoded-cs", 624 &xspi->is_decoded_cs); 625 if (ret < 0) 626 xspi->is_decoded_cs = 0; 627 } 628 629 cdns_spi_detect_fifo_depth(xspi); 630 631 /* SPI controller initializations */ 632 cdns_spi_init_hw(xspi, spi_controller_is_target(ctlr)); 633 634 irq = platform_get_irq(pdev, 0); 635 if (irq < 0) { 636 ret = irq; 637 goto clk_dis_all; 638 } 639 640 ret = devm_request_irq(&pdev->dev, irq, cdns_spi_irq, 641 0, pdev->name, ctlr); 642 if (ret != 0) { 643 ret = -ENXIO; 644 dev_err(&pdev->dev, "request_irq failed\n"); 645 goto clk_dis_all; 646 } 647 648 ctlr->use_gpio_descriptors = true; 649 ctlr->prepare_transfer_hardware = cdns_prepare_transfer_hardware; 650 ctlr->prepare_message = cdns_prepare_message; 651 ctlr->transfer_one = cdns_transfer_one; 652 ctlr->unprepare_transfer_hardware = cdns_unprepare_transfer_hardware; 653 ctlr->mode_bits = SPI_CPOL | SPI_CPHA; 654 ctlr->bits_per_word_mask = SPI_BPW_MASK(8); 655 656 if (!spi_controller_is_target(ctlr)) { 657 ctlr->mode_bits |= SPI_CS_HIGH; 658 ctlr->set_cs = cdns_spi_chipselect; 659 ctlr->auto_runtime_pm = true; 660 xspi->clk_rate = clk_get_rate(xspi->ref_clk); 661 /* Set to default valid value */ 662 ctlr->max_speed_hz = xspi->clk_rate / 4; 663 xspi->speed_hz = ctlr->max_speed_hz; 664 pm_runtime_mark_last_busy(&pdev->dev); 665 pm_runtime_put_autosuspend(&pdev->dev); 666 } else { 667 ctlr->mode_bits |= SPI_NO_CS; 668 ctlr->target_abort = cdns_target_abort; 669 } 670 ret = spi_register_controller(ctlr); 671 if (ret) { 672 dev_err(&pdev->dev, "spi_register_controller failed\n"); 673 goto clk_dis_all; 674 } 675 676 return ret; 677 678 clk_dis_all: 679 if (!spi_controller_is_target(ctlr)) { 680 pm_runtime_set_suspended(&pdev->dev); 681 pm_runtime_disable(&pdev->dev); 682 clk_disable_unprepare(xspi->ref_clk); 683 } 684 clk_dis_apb: 685 clk_disable_unprepare(xspi->pclk); 686 remove_ctlr: 687 spi_controller_put(ctlr); 688 return ret; 689 } 690 691 /** 692 * cdns_spi_remove - Remove method for the SPI driver 693 * @pdev: Pointer to the platform_device structure 694 * 695 * This function is called if a device is physically removed from the system or 696 * if the driver module is being unloaded. It frees all resources allocated to 697 * the device. 698 */ 699 static void cdns_spi_remove(struct platform_device *pdev) 700 { 701 struct spi_controller *ctlr = platform_get_drvdata(pdev); 702 struct cdns_spi *xspi = spi_controller_get_devdata(ctlr); 703 704 cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE); 705 706 clk_disable_unprepare(xspi->ref_clk); 707 clk_disable_unprepare(xspi->pclk); 708 pm_runtime_set_suspended(&pdev->dev); 709 pm_runtime_disable(&pdev->dev); 710 711 spi_unregister_controller(ctlr); 712 } 713 714 /** 715 * cdns_spi_suspend - Suspend method for the SPI driver 716 * @dev: Address of the platform_device structure 717 * 718 * This function disables the SPI controller and 719 * changes the driver state to "suspend" 720 * 721 * Return: 0 on success and error value on error 722 */ 723 static int __maybe_unused cdns_spi_suspend(struct device *dev) 724 { 725 struct spi_controller *ctlr = dev_get_drvdata(dev); 726 727 return spi_controller_suspend(ctlr); 728 } 729 730 /** 731 * cdns_spi_resume - Resume method for the SPI driver 732 * @dev: Address of the platform_device structure 733 * 734 * This function changes the driver state to "ready" 735 * 736 * Return: 0 on success and error value on error 737 */ 738 static int __maybe_unused cdns_spi_resume(struct device *dev) 739 { 740 struct spi_controller *ctlr = dev_get_drvdata(dev); 741 struct cdns_spi *xspi = spi_controller_get_devdata(ctlr); 742 743 cdns_spi_init_hw(xspi, spi_controller_is_target(ctlr)); 744 return spi_controller_resume(ctlr); 745 } 746 747 /** 748 * cdns_spi_runtime_resume - Runtime resume method for the SPI driver 749 * @dev: Address of the platform_device structure 750 * 751 * This function enables the clocks 752 * 753 * Return: 0 on success and error value on error 754 */ 755 static int __maybe_unused cdns_spi_runtime_resume(struct device *dev) 756 { 757 struct spi_controller *ctlr = dev_get_drvdata(dev); 758 struct cdns_spi *xspi = spi_controller_get_devdata(ctlr); 759 int ret; 760 761 ret = clk_prepare_enable(xspi->pclk); 762 if (ret) { 763 dev_err(dev, "Cannot enable APB clock.\n"); 764 return ret; 765 } 766 767 ret = clk_prepare_enable(xspi->ref_clk); 768 if (ret) { 769 dev_err(dev, "Cannot enable device clock.\n"); 770 clk_disable_unprepare(xspi->pclk); 771 return ret; 772 } 773 return 0; 774 } 775 776 /** 777 * cdns_spi_runtime_suspend - Runtime suspend method for the SPI driver 778 * @dev: Address of the platform_device structure 779 * 780 * This function disables the clocks 781 * 782 * Return: Always 0 783 */ 784 static int __maybe_unused cdns_spi_runtime_suspend(struct device *dev) 785 { 786 struct spi_controller *ctlr = dev_get_drvdata(dev); 787 struct cdns_spi *xspi = spi_controller_get_devdata(ctlr); 788 789 clk_disable_unprepare(xspi->ref_clk); 790 clk_disable_unprepare(xspi->pclk); 791 792 return 0; 793 } 794 795 static const struct dev_pm_ops cdns_spi_dev_pm_ops = { 796 SET_RUNTIME_PM_OPS(cdns_spi_runtime_suspend, 797 cdns_spi_runtime_resume, NULL) 798 SET_SYSTEM_SLEEP_PM_OPS(cdns_spi_suspend, cdns_spi_resume) 799 }; 800 801 static const struct of_device_id cdns_spi_of_match[] = { 802 { .compatible = "xlnx,zynq-spi-r1p6" }, 803 { .compatible = "cdns,spi-r1p6" }, 804 { /* end of table */ } 805 }; 806 MODULE_DEVICE_TABLE(of, cdns_spi_of_match); 807 808 /* cdns_spi_driver - This structure defines the SPI subsystem platform driver */ 809 static struct platform_driver cdns_spi_driver = { 810 .probe = cdns_spi_probe, 811 .remove_new = cdns_spi_remove, 812 .driver = { 813 .name = CDNS_SPI_NAME, 814 .of_match_table = cdns_spi_of_match, 815 .pm = &cdns_spi_dev_pm_ops, 816 }, 817 }; 818 819 module_platform_driver(cdns_spi_driver); 820 821 MODULE_AUTHOR("Xilinx, Inc."); 822 MODULE_DESCRIPTION("Cadence SPI driver"); 823 MODULE_LICENSE("GPL"); 824