1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Freescale/Motorola Coldfire Queued SPI driver 4 * 5 * Copyright 2010 Steven King <sfking@fdwdc.com> 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/interrupt.h> 11 #include <linux/errno.h> 12 #include <linux/platform_device.h> 13 #include <linux/sched.h> 14 #include <linux/delay.h> 15 #include <linux/io.h> 16 #include <linux/clk.h> 17 #include <linux/err.h> 18 #include <linux/spi/spi.h> 19 #include <linux/pm_runtime.h> 20 21 #include <asm/coldfire.h> 22 #include <asm/mcfsim.h> 23 #include <asm/mcfqspi.h> 24 25 #define DRIVER_NAME "mcfqspi" 26 27 #define MCFQSPI_BUSCLK (MCF_BUSCLK / 2) 28 29 #define MCFQSPI_QMR 0x00 30 #define MCFQSPI_QMR_MSTR 0x8000 31 #define MCFQSPI_QMR_CPOL 0x0200 32 #define MCFQSPI_QMR_CPHA 0x0100 33 #define MCFQSPI_QDLYR 0x04 34 #define MCFQSPI_QDLYR_SPE 0x8000 35 #define MCFQSPI_QWR 0x08 36 #define MCFQSPI_QWR_HALT 0x8000 37 #define MCFQSPI_QWR_WREN 0x4000 38 #define MCFQSPI_QWR_CSIV 0x1000 39 #define MCFQSPI_QIR 0x0C 40 #define MCFQSPI_QIR_WCEFB 0x8000 41 #define MCFQSPI_QIR_ABRTB 0x4000 42 #define MCFQSPI_QIR_ABRTL 0x1000 43 #define MCFQSPI_QIR_WCEFE 0x0800 44 #define MCFQSPI_QIR_ABRTE 0x0400 45 #define MCFQSPI_QIR_SPIFE 0x0100 46 #define MCFQSPI_QIR_WCEF 0x0008 47 #define MCFQSPI_QIR_ABRT 0x0004 48 #define MCFQSPI_QIR_SPIF 0x0001 49 #define MCFQSPI_QAR 0x010 50 #define MCFQSPI_QAR_TXBUF 0x00 51 #define MCFQSPI_QAR_RXBUF 0x10 52 #define MCFQSPI_QAR_CMDBUF 0x20 53 #define MCFQSPI_QDR 0x014 54 #define MCFQSPI_QCR 0x014 55 #define MCFQSPI_QCR_CONT 0x8000 56 #define MCFQSPI_QCR_BITSE 0x4000 57 #define MCFQSPI_QCR_DT 0x2000 58 59 struct mcfqspi { 60 void __iomem *iobase; 61 int irq; 62 struct clk *clk; 63 struct mcfqspi_cs_control *cs_control; 64 65 wait_queue_head_t waitq; 66 }; 67 68 static void mcfqspi_wr_qmr(struct mcfqspi *mcfqspi, u16 val) 69 { 70 writew(val, mcfqspi->iobase + MCFQSPI_QMR); 71 } 72 73 static void mcfqspi_wr_qdlyr(struct mcfqspi *mcfqspi, u16 val) 74 { 75 writew(val, mcfqspi->iobase + MCFQSPI_QDLYR); 76 } 77 78 static u16 mcfqspi_rd_qdlyr(struct mcfqspi *mcfqspi) 79 { 80 return readw(mcfqspi->iobase + MCFQSPI_QDLYR); 81 } 82 83 static void mcfqspi_wr_qwr(struct mcfqspi *mcfqspi, u16 val) 84 { 85 writew(val, mcfqspi->iobase + MCFQSPI_QWR); 86 } 87 88 static void mcfqspi_wr_qir(struct mcfqspi *mcfqspi, u16 val) 89 { 90 writew(val, mcfqspi->iobase + MCFQSPI_QIR); 91 } 92 93 static void mcfqspi_wr_qar(struct mcfqspi *mcfqspi, u16 val) 94 { 95 writew(val, mcfqspi->iobase + MCFQSPI_QAR); 96 } 97 98 static void mcfqspi_wr_qdr(struct mcfqspi *mcfqspi, u16 val) 99 { 100 writew(val, mcfqspi->iobase + MCFQSPI_QDR); 101 } 102 103 static u16 mcfqspi_rd_qdr(struct mcfqspi *mcfqspi) 104 { 105 return readw(mcfqspi->iobase + MCFQSPI_QDR); 106 } 107 108 static void mcfqspi_cs_select(struct mcfqspi *mcfqspi, u8 chip_select, 109 bool cs_high) 110 { 111 mcfqspi->cs_control->select(mcfqspi->cs_control, chip_select, cs_high); 112 } 113 114 static void mcfqspi_cs_deselect(struct mcfqspi *mcfqspi, u8 chip_select, 115 bool cs_high) 116 { 117 mcfqspi->cs_control->deselect(mcfqspi->cs_control, chip_select, cs_high); 118 } 119 120 static int mcfqspi_cs_setup(struct mcfqspi *mcfqspi) 121 { 122 return (mcfqspi->cs_control->setup) ? 123 mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0; 124 } 125 126 static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi) 127 { 128 if (mcfqspi->cs_control->teardown) 129 mcfqspi->cs_control->teardown(mcfqspi->cs_control); 130 } 131 132 static u8 mcfqspi_qmr_baud(u32 speed_hz) 133 { 134 return clamp((MCFQSPI_BUSCLK + speed_hz - 1) / speed_hz, 2u, 255u); 135 } 136 137 static bool mcfqspi_qdlyr_spe(struct mcfqspi *mcfqspi) 138 { 139 return mcfqspi_rd_qdlyr(mcfqspi) & MCFQSPI_QDLYR_SPE; 140 } 141 142 static irqreturn_t mcfqspi_irq_handler(int this_irq, void *dev_id) 143 { 144 struct mcfqspi *mcfqspi = dev_id; 145 146 /* clear interrupt */ 147 mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE | MCFQSPI_QIR_SPIF); 148 wake_up(&mcfqspi->waitq); 149 150 return IRQ_HANDLED; 151 } 152 153 static void mcfqspi_transfer_msg8(struct mcfqspi *mcfqspi, unsigned count, 154 const u8 *txbuf, u8 *rxbuf) 155 { 156 unsigned i, n, offset = 0; 157 158 n = min(count, 16u); 159 160 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF); 161 for (i = 0; i < n; ++i) 162 mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE); 163 164 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF); 165 if (txbuf) 166 for (i = 0; i < n; ++i) 167 mcfqspi_wr_qdr(mcfqspi, *txbuf++); 168 else 169 for (i = 0; i < count; ++i) 170 mcfqspi_wr_qdr(mcfqspi, 0); 171 172 count -= n; 173 if (count) { 174 u16 qwr = 0xf08; 175 mcfqspi_wr_qwr(mcfqspi, 0x700); 176 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); 177 178 do { 179 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); 180 mcfqspi_wr_qwr(mcfqspi, qwr); 181 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); 182 if (rxbuf) { 183 mcfqspi_wr_qar(mcfqspi, 184 MCFQSPI_QAR_RXBUF + offset); 185 for (i = 0; i < 8; ++i) 186 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); 187 } 188 n = min(count, 8u); 189 if (txbuf) { 190 mcfqspi_wr_qar(mcfqspi, 191 MCFQSPI_QAR_TXBUF + offset); 192 for (i = 0; i < n; ++i) 193 mcfqspi_wr_qdr(mcfqspi, *txbuf++); 194 } 195 qwr = (offset ? 0x808 : 0) + ((n - 1) << 8); 196 offset ^= 8; 197 count -= n; 198 } while (count); 199 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); 200 mcfqspi_wr_qwr(mcfqspi, qwr); 201 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); 202 if (rxbuf) { 203 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset); 204 for (i = 0; i < 8; ++i) 205 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); 206 offset ^= 8; 207 } 208 } else { 209 mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8); 210 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); 211 } 212 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); 213 if (rxbuf) { 214 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset); 215 for (i = 0; i < n; ++i) 216 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); 217 } 218 } 219 220 static void mcfqspi_transfer_msg16(struct mcfqspi *mcfqspi, unsigned count, 221 const u16 *txbuf, u16 *rxbuf) 222 { 223 unsigned i, n, offset = 0; 224 225 n = min(count, 16u); 226 227 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF); 228 for (i = 0; i < n; ++i) 229 mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE); 230 231 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF); 232 if (txbuf) 233 for (i = 0; i < n; ++i) 234 mcfqspi_wr_qdr(mcfqspi, *txbuf++); 235 else 236 for (i = 0; i < count; ++i) 237 mcfqspi_wr_qdr(mcfqspi, 0); 238 239 count -= n; 240 if (count) { 241 u16 qwr = 0xf08; 242 mcfqspi_wr_qwr(mcfqspi, 0x700); 243 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); 244 245 do { 246 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); 247 mcfqspi_wr_qwr(mcfqspi, qwr); 248 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); 249 if (rxbuf) { 250 mcfqspi_wr_qar(mcfqspi, 251 MCFQSPI_QAR_RXBUF + offset); 252 for (i = 0; i < 8; ++i) 253 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); 254 } 255 n = min(count, 8u); 256 if (txbuf) { 257 mcfqspi_wr_qar(mcfqspi, 258 MCFQSPI_QAR_TXBUF + offset); 259 for (i = 0; i < n; ++i) 260 mcfqspi_wr_qdr(mcfqspi, *txbuf++); 261 } 262 qwr = (offset ? 0x808 : 0x000) + ((n - 1) << 8); 263 offset ^= 8; 264 count -= n; 265 } while (count); 266 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); 267 mcfqspi_wr_qwr(mcfqspi, qwr); 268 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); 269 if (rxbuf) { 270 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset); 271 for (i = 0; i < 8; ++i) 272 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); 273 offset ^= 8; 274 } 275 } else { 276 mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8); 277 mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE); 278 } 279 wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi)); 280 if (rxbuf) { 281 mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset); 282 for (i = 0; i < n; ++i) 283 *rxbuf++ = mcfqspi_rd_qdr(mcfqspi); 284 } 285 } 286 287 static void mcfqspi_set_cs(struct spi_device *spi, bool enable) 288 { 289 struct mcfqspi *mcfqspi = spi_controller_get_devdata(spi->controller); 290 bool cs_high = spi->mode & SPI_CS_HIGH; 291 292 if (enable) 293 mcfqspi_cs_select(mcfqspi, spi_get_chipselect(spi, 0), cs_high); 294 else 295 mcfqspi_cs_deselect(mcfqspi, spi_get_chipselect(spi, 0), cs_high); 296 } 297 298 static int mcfqspi_transfer_one(struct spi_controller *host, 299 struct spi_device *spi, 300 struct spi_transfer *t) 301 { 302 struct mcfqspi *mcfqspi = spi_controller_get_devdata(host); 303 u16 qmr = MCFQSPI_QMR_MSTR; 304 305 qmr |= t->bits_per_word << 10; 306 if (spi->mode & SPI_CPHA) 307 qmr |= MCFQSPI_QMR_CPHA; 308 if (spi->mode & SPI_CPOL) 309 qmr |= MCFQSPI_QMR_CPOL; 310 qmr |= mcfqspi_qmr_baud(t->speed_hz); 311 mcfqspi_wr_qmr(mcfqspi, qmr); 312 313 mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE); 314 if (t->bits_per_word == 8) 315 mcfqspi_transfer_msg8(mcfqspi, t->len, t->tx_buf, t->rx_buf); 316 else 317 mcfqspi_transfer_msg16(mcfqspi, t->len / 2, t->tx_buf, 318 t->rx_buf); 319 mcfqspi_wr_qir(mcfqspi, 0); 320 321 return 0; 322 } 323 324 static int mcfqspi_setup(struct spi_device *spi) 325 { 326 mcfqspi_cs_deselect(spi_controller_get_devdata(spi->controller), 327 spi_get_chipselect(spi, 0), spi->mode & SPI_CS_HIGH); 328 329 dev_dbg(&spi->dev, 330 "bits per word %d, chip select %d, speed %d KHz\n", 331 spi->bits_per_word, spi_get_chipselect(spi, 0), 332 (MCFQSPI_BUSCLK / mcfqspi_qmr_baud(spi->max_speed_hz)) 333 / 1000); 334 335 return 0; 336 } 337 338 static int mcfqspi_probe(struct platform_device *pdev) 339 { 340 struct spi_controller *host; 341 struct mcfqspi *mcfqspi; 342 struct mcfqspi_platform_data *pdata; 343 int status; 344 345 pdata = dev_get_platdata(&pdev->dev); 346 if (!pdata) { 347 dev_dbg(&pdev->dev, "platform data is missing\n"); 348 return -ENOENT; 349 } 350 351 if (!pdata->cs_control) { 352 dev_dbg(&pdev->dev, "pdata->cs_control is NULL\n"); 353 return -EINVAL; 354 } 355 356 host = spi_alloc_host(&pdev->dev, sizeof(*mcfqspi)); 357 if (host == NULL) { 358 dev_dbg(&pdev->dev, "spi_alloc_host failed\n"); 359 return -ENOMEM; 360 } 361 362 mcfqspi = spi_controller_get_devdata(host); 363 364 mcfqspi->iobase = devm_platform_ioremap_resource(pdev, 0); 365 if (IS_ERR(mcfqspi->iobase)) { 366 status = PTR_ERR(mcfqspi->iobase); 367 goto fail0; 368 } 369 370 mcfqspi->irq = platform_get_irq(pdev, 0); 371 if (mcfqspi->irq < 0) { 372 dev_dbg(&pdev->dev, "platform_get_irq failed\n"); 373 status = -ENXIO; 374 goto fail0; 375 } 376 377 status = devm_request_irq(&pdev->dev, mcfqspi->irq, mcfqspi_irq_handler, 378 0, pdev->name, mcfqspi); 379 if (status) { 380 dev_dbg(&pdev->dev, "request_irq failed\n"); 381 goto fail0; 382 } 383 384 mcfqspi->clk = devm_clk_get_enabled(&pdev->dev, "qspi_clk"); 385 if (IS_ERR(mcfqspi->clk)) { 386 dev_dbg(&pdev->dev, "clk_get failed\n"); 387 status = PTR_ERR(mcfqspi->clk); 388 goto fail0; 389 } 390 391 host->bus_num = pdata->bus_num; 392 host->num_chipselect = pdata->num_chipselect; 393 394 mcfqspi->cs_control = pdata->cs_control; 395 status = mcfqspi_cs_setup(mcfqspi); 396 if (status) { 397 dev_dbg(&pdev->dev, "error initializing cs_control\n"); 398 goto fail0; 399 } 400 401 init_waitqueue_head(&mcfqspi->waitq); 402 403 host->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA; 404 host->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16); 405 host->setup = mcfqspi_setup; 406 host->set_cs = mcfqspi_set_cs; 407 host->transfer_one = mcfqspi_transfer_one; 408 host->auto_runtime_pm = true; 409 410 platform_set_drvdata(pdev, host); 411 pm_runtime_enable(&pdev->dev); 412 413 status = devm_spi_register_controller(&pdev->dev, host); 414 if (status) { 415 dev_dbg(&pdev->dev, "devm_spi_register_controller failed\n"); 416 goto fail1; 417 } 418 419 dev_info(&pdev->dev, "Coldfire QSPI bus driver\n"); 420 421 return 0; 422 423 fail1: 424 pm_runtime_disable(&pdev->dev); 425 mcfqspi_cs_teardown(mcfqspi); 426 fail0: 427 spi_controller_put(host); 428 429 dev_dbg(&pdev->dev, "Coldfire QSPI probe failed\n"); 430 431 return status; 432 } 433 434 static void mcfqspi_remove(struct platform_device *pdev) 435 { 436 struct spi_controller *host = platform_get_drvdata(pdev); 437 struct mcfqspi *mcfqspi = spi_controller_get_devdata(host); 438 439 pm_runtime_disable(&pdev->dev); 440 /* disable the hardware (set the baud rate to 0) */ 441 mcfqspi_wr_qmr(mcfqspi, MCFQSPI_QMR_MSTR); 442 443 mcfqspi_cs_teardown(mcfqspi); 444 clk_disable_unprepare(mcfqspi->clk); 445 } 446 447 #ifdef CONFIG_PM_SLEEP 448 static int mcfqspi_suspend(struct device *dev) 449 { 450 struct spi_controller *host = dev_get_drvdata(dev); 451 struct mcfqspi *mcfqspi = spi_controller_get_devdata(host); 452 int ret; 453 454 ret = spi_controller_suspend(host); 455 if (ret) 456 return ret; 457 458 clk_disable(mcfqspi->clk); 459 460 return 0; 461 } 462 463 static int mcfqspi_resume(struct device *dev) 464 { 465 struct spi_controller *host = dev_get_drvdata(dev); 466 struct mcfqspi *mcfqspi = spi_controller_get_devdata(host); 467 468 clk_enable(mcfqspi->clk); 469 470 return spi_controller_resume(host); 471 } 472 #endif 473 474 #ifdef CONFIG_PM 475 static int mcfqspi_runtime_suspend(struct device *dev) 476 { 477 struct spi_controller *host = dev_get_drvdata(dev); 478 struct mcfqspi *mcfqspi = spi_controller_get_devdata(host); 479 480 clk_disable(mcfqspi->clk); 481 482 return 0; 483 } 484 485 static int mcfqspi_runtime_resume(struct device *dev) 486 { 487 struct spi_controller *host = dev_get_drvdata(dev); 488 struct mcfqspi *mcfqspi = spi_controller_get_devdata(host); 489 490 clk_enable(mcfqspi->clk); 491 492 return 0; 493 } 494 #endif 495 496 static const struct dev_pm_ops mcfqspi_pm = { 497 SET_SYSTEM_SLEEP_PM_OPS(mcfqspi_suspend, mcfqspi_resume) 498 SET_RUNTIME_PM_OPS(mcfqspi_runtime_suspend, mcfqspi_runtime_resume, 499 NULL) 500 }; 501 502 static struct platform_driver mcfqspi_driver = { 503 .driver.name = DRIVER_NAME, 504 .driver.owner = THIS_MODULE, 505 .driver.pm = &mcfqspi_pm, 506 .probe = mcfqspi_probe, 507 .remove_new = mcfqspi_remove, 508 }; 509 module_platform_driver(mcfqspi_driver); 510 511 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>"); 512 MODULE_DESCRIPTION("Coldfire QSPI Controller Driver"); 513 MODULE_LICENSE("GPL"); 514 MODULE_ALIAS("platform:" DRIVER_NAME); 515