1 /* 2 * MPC52xx PSC in SPI mode driver. 3 * 4 * Maintainer: Dragos Carp 5 * 6 * Copyright (C) 2006 TOPTICA Photonics AG. 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License as published by the 10 * Free Software Foundation; either version 2 of the License, or (at your 11 * option) any later version. 12 */ 13 14 #include <linux/module.h> 15 #include <linux/init.h> 16 #include <linux/types.h> 17 #include <linux/errno.h> 18 #include <linux/interrupt.h> 19 #include <linux/of_address.h> 20 #include <linux/of_platform.h> 21 #include <linux/workqueue.h> 22 #include <linux/completion.h> 23 #include <linux/io.h> 24 #include <linux/delay.h> 25 #include <linux/spi/spi.h> 26 #include <linux/fsl_devices.h> 27 #include <linux/slab.h> 28 29 #include <asm/mpc52xx.h> 30 #include <asm/mpc52xx_psc.h> 31 32 #define MCLK 20000000 /* PSC port MClk in hz */ 33 34 struct mpc52xx_psc_spi { 35 /* fsl_spi_platform data */ 36 void (*cs_control)(struct spi_device *spi, bool on); 37 u32 sysclk; 38 39 /* driver internal data */ 40 struct mpc52xx_psc __iomem *psc; 41 struct mpc52xx_psc_fifo __iomem *fifo; 42 unsigned int irq; 43 u8 bits_per_word; 44 u8 busy; 45 46 struct workqueue_struct *workqueue; 47 struct work_struct work; 48 49 struct list_head queue; 50 spinlock_t lock; 51 52 struct completion done; 53 }; 54 55 /* controller state */ 56 struct mpc52xx_psc_spi_cs { 57 int bits_per_word; 58 int speed_hz; 59 }; 60 61 /* set clock freq, clock ramp, bits per work 62 * if t is NULL then reset the values to the default values 63 */ 64 static int mpc52xx_psc_spi_transfer_setup(struct spi_device *spi, 65 struct spi_transfer *t) 66 { 67 struct mpc52xx_psc_spi_cs *cs = spi->controller_state; 68 69 cs->speed_hz = (t && t->speed_hz) 70 ? t->speed_hz : spi->max_speed_hz; 71 cs->bits_per_word = (t && t->bits_per_word) 72 ? t->bits_per_word : spi->bits_per_word; 73 cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8; 74 return 0; 75 } 76 77 static void mpc52xx_psc_spi_activate_cs(struct spi_device *spi) 78 { 79 struct mpc52xx_psc_spi_cs *cs = spi->controller_state; 80 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); 81 struct mpc52xx_psc __iomem *psc = mps->psc; 82 u32 sicr; 83 u16 ccr; 84 85 sicr = in_be32(&psc->sicr); 86 87 /* Set clock phase and polarity */ 88 if (spi->mode & SPI_CPHA) 89 sicr |= 0x00001000; 90 else 91 sicr &= ~0x00001000; 92 if (spi->mode & SPI_CPOL) 93 sicr |= 0x00002000; 94 else 95 sicr &= ~0x00002000; 96 97 if (spi->mode & SPI_LSB_FIRST) 98 sicr |= 0x10000000; 99 else 100 sicr &= ~0x10000000; 101 out_be32(&psc->sicr, sicr); 102 103 /* Set clock frequency and bits per word 104 * Because psc->ccr is defined as 16bit register instead of 32bit 105 * just set the lower byte of BitClkDiv 106 */ 107 ccr = in_be16((u16 __iomem *)&psc->ccr); 108 ccr &= 0xFF00; 109 if (cs->speed_hz) 110 ccr |= (MCLK / cs->speed_hz - 1) & 0xFF; 111 else /* by default SPI Clk 1MHz */ 112 ccr |= (MCLK / 1000000 - 1) & 0xFF; 113 out_be16((u16 __iomem *)&psc->ccr, ccr); 114 mps->bits_per_word = cs->bits_per_word; 115 116 if (mps->cs_control) 117 mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0); 118 } 119 120 static void mpc52xx_psc_spi_deactivate_cs(struct spi_device *spi) 121 { 122 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); 123 124 if (mps->cs_control) 125 mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1); 126 } 127 128 #define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1) 129 /* wake up when 80% fifo full */ 130 #define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100) 131 132 static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi, 133 struct spi_transfer *t) 134 { 135 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); 136 struct mpc52xx_psc __iomem *psc = mps->psc; 137 struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo; 138 unsigned rb = 0; /* number of bytes receieved */ 139 unsigned sb = 0; /* number of bytes sent */ 140 unsigned char *rx_buf = (unsigned char *)t->rx_buf; 141 unsigned char *tx_buf = (unsigned char *)t->tx_buf; 142 unsigned rfalarm; 143 unsigned send_at_once = MPC52xx_PSC_BUFSIZE; 144 unsigned recv_at_once; 145 int last_block = 0; 146 147 if (!t->tx_buf && !t->rx_buf && t->len) 148 return -EINVAL; 149 150 /* enable transmiter/receiver */ 151 out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE); 152 while (rb < t->len) { 153 if (t->len - rb > MPC52xx_PSC_BUFSIZE) { 154 rfalarm = MPC52xx_PSC_RFALARM; 155 last_block = 0; 156 } else { 157 send_at_once = t->len - sb; 158 rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb); 159 last_block = 1; 160 } 161 162 dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once); 163 for (; send_at_once; sb++, send_at_once--) { 164 /* set EOF flag before the last word is sent */ 165 if (send_at_once == 1 && last_block) 166 out_8(&psc->ircr2, 0x01); 167 168 if (tx_buf) 169 out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]); 170 else 171 out_8(&psc->mpc52xx_psc_buffer_8, 0); 172 } 173 174 175 /* enable interrupts and wait for wake up 176 * if just one byte is expected the Rx FIFO genererates no 177 * FFULL interrupt, so activate the RxRDY interrupt 178 */ 179 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1); 180 if (t->len - rb == 1) { 181 out_8(&psc->mode, 0); 182 } else { 183 out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL); 184 out_be16(&fifo->rfalarm, rfalarm); 185 } 186 out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY); 187 wait_for_completion(&mps->done); 188 recv_at_once = in_be16(&fifo->rfnum); 189 dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once); 190 191 send_at_once = recv_at_once; 192 if (rx_buf) { 193 for (; recv_at_once; rb++, recv_at_once--) 194 rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8); 195 } else { 196 for (; recv_at_once; rb++, recv_at_once--) 197 in_8(&psc->mpc52xx_psc_buffer_8); 198 } 199 } 200 /* disable transmiter/receiver */ 201 out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE); 202 203 return 0; 204 } 205 206 static void mpc52xx_psc_spi_work(struct work_struct *work) 207 { 208 struct mpc52xx_psc_spi *mps = 209 container_of(work, struct mpc52xx_psc_spi, work); 210 211 spin_lock_irq(&mps->lock); 212 mps->busy = 1; 213 while (!list_empty(&mps->queue)) { 214 struct spi_message *m; 215 struct spi_device *spi; 216 struct spi_transfer *t = NULL; 217 unsigned cs_change; 218 int status; 219 220 m = container_of(mps->queue.next, struct spi_message, queue); 221 list_del_init(&m->queue); 222 spin_unlock_irq(&mps->lock); 223 224 spi = m->spi; 225 cs_change = 1; 226 status = 0; 227 list_for_each_entry (t, &m->transfers, transfer_list) { 228 if (t->bits_per_word || t->speed_hz) { 229 status = mpc52xx_psc_spi_transfer_setup(spi, t); 230 if (status < 0) 231 break; 232 } 233 234 if (cs_change) 235 mpc52xx_psc_spi_activate_cs(spi); 236 cs_change = t->cs_change; 237 238 status = mpc52xx_psc_spi_transfer_rxtx(spi, t); 239 if (status) 240 break; 241 m->actual_length += t->len; 242 243 if (t->delay_usecs) 244 udelay(t->delay_usecs); 245 246 if (cs_change) 247 mpc52xx_psc_spi_deactivate_cs(spi); 248 } 249 250 m->status = status; 251 m->complete(m->context); 252 253 if (status || !cs_change) 254 mpc52xx_psc_spi_deactivate_cs(spi); 255 256 mpc52xx_psc_spi_transfer_setup(spi, NULL); 257 258 spin_lock_irq(&mps->lock); 259 } 260 mps->busy = 0; 261 spin_unlock_irq(&mps->lock); 262 } 263 264 static int mpc52xx_psc_spi_setup(struct spi_device *spi) 265 { 266 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); 267 struct mpc52xx_psc_spi_cs *cs = spi->controller_state; 268 unsigned long flags; 269 270 if (spi->bits_per_word%8) 271 return -EINVAL; 272 273 if (!cs) { 274 cs = kzalloc(sizeof *cs, GFP_KERNEL); 275 if (!cs) 276 return -ENOMEM; 277 spi->controller_state = cs; 278 } 279 280 cs->bits_per_word = spi->bits_per_word; 281 cs->speed_hz = spi->max_speed_hz; 282 283 spin_lock_irqsave(&mps->lock, flags); 284 if (!mps->busy) 285 mpc52xx_psc_spi_deactivate_cs(spi); 286 spin_unlock_irqrestore(&mps->lock, flags); 287 288 return 0; 289 } 290 291 static int mpc52xx_psc_spi_transfer(struct spi_device *spi, 292 struct spi_message *m) 293 { 294 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); 295 unsigned long flags; 296 297 m->actual_length = 0; 298 m->status = -EINPROGRESS; 299 300 spin_lock_irqsave(&mps->lock, flags); 301 list_add_tail(&m->queue, &mps->queue); 302 queue_work(mps->workqueue, &mps->work); 303 spin_unlock_irqrestore(&mps->lock, flags); 304 305 return 0; 306 } 307 308 static void mpc52xx_psc_spi_cleanup(struct spi_device *spi) 309 { 310 kfree(spi->controller_state); 311 } 312 313 static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps) 314 { 315 struct mpc52xx_psc __iomem *psc = mps->psc; 316 struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo; 317 u32 mclken_div; 318 int ret; 319 320 /* default sysclk is 512MHz */ 321 mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK; 322 ret = mpc52xx_set_psc_clkdiv(psc_id, mclken_div); 323 if (ret) 324 return ret; 325 326 /* Reset the PSC into a known state */ 327 out_8(&psc->command, MPC52xx_PSC_RST_RX); 328 out_8(&psc->command, MPC52xx_PSC_RST_TX); 329 out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE); 330 331 /* Disable interrupts, interrupts are based on alarm level */ 332 out_be16(&psc->mpc52xx_psc_imr, 0); 333 out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1); 334 out_8(&fifo->rfcntl, 0); 335 out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL); 336 337 /* Configure 8bit codec mode as a SPI master and use EOF flags */ 338 /* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */ 339 out_be32(&psc->sicr, 0x0180C800); 340 out_be16((u16 __iomem *)&psc->ccr, 0x070F); /* default SPI Clk 1MHz */ 341 342 /* Set 2ms DTL delay */ 343 out_8(&psc->ctur, 0x00); 344 out_8(&psc->ctlr, 0x84); 345 346 mps->bits_per_word = 8; 347 348 return 0; 349 } 350 351 static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id) 352 { 353 struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id; 354 struct mpc52xx_psc __iomem *psc = mps->psc; 355 356 /* disable interrupt and wake up the work queue */ 357 if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) { 358 out_be16(&psc->mpc52xx_psc_imr, 0); 359 complete(&mps->done); 360 return IRQ_HANDLED; 361 } 362 return IRQ_NONE; 363 } 364 365 /* bus_num is used only for the case dev->platform_data == NULL */ 366 static int mpc52xx_psc_spi_do_probe(struct device *dev, u32 regaddr, 367 u32 size, unsigned int irq, s16 bus_num) 368 { 369 struct fsl_spi_platform_data *pdata = dev_get_platdata(dev); 370 struct mpc52xx_psc_spi *mps; 371 struct spi_master *master; 372 int ret; 373 374 master = spi_alloc_master(dev, sizeof *mps); 375 if (master == NULL) 376 return -ENOMEM; 377 378 dev_set_drvdata(dev, master); 379 mps = spi_master_get_devdata(master); 380 381 /* the spi->mode bits understood by this driver: */ 382 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST; 383 384 mps->irq = irq; 385 if (pdata == NULL) { 386 dev_warn(dev, "probe called without platform data, no " 387 "cs_control function will be called\n"); 388 mps->cs_control = NULL; 389 mps->sysclk = 0; 390 master->bus_num = bus_num; 391 master->num_chipselect = 255; 392 } else { 393 mps->cs_control = pdata->cs_control; 394 mps->sysclk = pdata->sysclk; 395 master->bus_num = pdata->bus_num; 396 master->num_chipselect = pdata->max_chipselect; 397 } 398 master->setup = mpc52xx_psc_spi_setup; 399 master->transfer = mpc52xx_psc_spi_transfer; 400 master->cleanup = mpc52xx_psc_spi_cleanup; 401 master->dev.of_node = dev->of_node; 402 403 mps->psc = ioremap(regaddr, size); 404 if (!mps->psc) { 405 dev_err(dev, "could not ioremap I/O port range\n"); 406 ret = -EFAULT; 407 goto free_master; 408 } 409 /* On the 5200, fifo regs are immediately ajacent to the psc regs */ 410 mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc); 411 412 ret = request_irq(mps->irq, mpc52xx_psc_spi_isr, 0, "mpc52xx-psc-spi", 413 mps); 414 if (ret) 415 goto free_master; 416 417 ret = mpc52xx_psc_spi_port_config(master->bus_num, mps); 418 if (ret < 0) { 419 dev_err(dev, "can't configure PSC! Is it capable of SPI?\n"); 420 goto free_irq; 421 } 422 423 spin_lock_init(&mps->lock); 424 init_completion(&mps->done); 425 INIT_WORK(&mps->work, mpc52xx_psc_spi_work); 426 INIT_LIST_HEAD(&mps->queue); 427 428 mps->workqueue = create_singlethread_workqueue( 429 dev_name(master->dev.parent)); 430 if (mps->workqueue == NULL) { 431 ret = -EBUSY; 432 goto free_irq; 433 } 434 435 ret = spi_register_master(master); 436 if (ret < 0) 437 goto unreg_master; 438 439 return ret; 440 441 unreg_master: 442 destroy_workqueue(mps->workqueue); 443 free_irq: 444 free_irq(mps->irq, mps); 445 free_master: 446 if (mps->psc) 447 iounmap(mps->psc); 448 spi_master_put(master); 449 450 return ret; 451 } 452 453 static int mpc52xx_psc_spi_of_probe(struct platform_device *op) 454 { 455 const u32 *regaddr_p; 456 u64 regaddr64, size64; 457 s16 id = -1; 458 459 regaddr_p = of_get_address(op->dev.of_node, 0, &size64, NULL); 460 if (!regaddr_p) { 461 dev_err(&op->dev, "Invalid PSC address\n"); 462 return -EINVAL; 463 } 464 regaddr64 = of_translate_address(op->dev.of_node, regaddr_p); 465 466 /* get PSC id (1..6, used by port_config) */ 467 if (op->dev.platform_data == NULL) { 468 const u32 *psc_nump; 469 470 psc_nump = of_get_property(op->dev.of_node, "cell-index", NULL); 471 if (!psc_nump || *psc_nump > 5) { 472 dev_err(&op->dev, "Invalid cell-index property\n"); 473 return -EINVAL; 474 } 475 id = *psc_nump + 1; 476 } 477 478 return mpc52xx_psc_spi_do_probe(&op->dev, (u32)regaddr64, (u32)size64, 479 irq_of_parse_and_map(op->dev.of_node, 0), id); 480 } 481 482 static int mpc52xx_psc_spi_of_remove(struct platform_device *op) 483 { 484 struct spi_master *master = spi_master_get(platform_get_drvdata(op)); 485 struct mpc52xx_psc_spi *mps = spi_master_get_devdata(master); 486 487 flush_workqueue(mps->workqueue); 488 destroy_workqueue(mps->workqueue); 489 spi_unregister_master(master); 490 free_irq(mps->irq, mps); 491 if (mps->psc) 492 iounmap(mps->psc); 493 spi_master_put(master); 494 495 return 0; 496 } 497 498 static const struct of_device_id mpc52xx_psc_spi_of_match[] = { 499 { .compatible = "fsl,mpc5200-psc-spi", }, 500 { .compatible = "mpc5200-psc-spi", }, /* old */ 501 {} 502 }; 503 504 MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match); 505 506 static struct platform_driver mpc52xx_psc_spi_of_driver = { 507 .probe = mpc52xx_psc_spi_of_probe, 508 .remove = mpc52xx_psc_spi_of_remove, 509 .driver = { 510 .name = "mpc52xx-psc-spi", 511 .owner = THIS_MODULE, 512 .of_match_table = mpc52xx_psc_spi_of_match, 513 }, 514 }; 515 module_platform_driver(mpc52xx_psc_spi_of_driver); 516 517 MODULE_AUTHOR("Dragos Carp"); 518 MODULE_DESCRIPTION("MPC52xx PSC SPI Driver"); 519 MODULE_LICENSE("GPL"); 520