1 /* 2 * Broadcom BCM63xx SPI controller support 3 * 4 * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org> 5 * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 2 10 * of the License, or (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the 19 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 20 */ 21 22 #include <linux/kernel.h> 23 #include <linux/init.h> 24 #include <linux/clk.h> 25 #include <linux/io.h> 26 #include <linux/module.h> 27 #include <linux/platform_device.h> 28 #include <linux/delay.h> 29 #include <linux/interrupt.h> 30 #include <linux/spi/spi.h> 31 #include <linux/completion.h> 32 #include <linux/err.h> 33 #include <linux/workqueue.h> 34 #include <linux/pm_runtime.h> 35 36 #include <bcm63xx_dev_spi.h> 37 38 #define PFX KBUILD_MODNAME 39 #define DRV_VER "0.1.2" 40 41 struct bcm63xx_spi { 42 struct completion done; 43 44 void __iomem *regs; 45 int irq; 46 47 /* Platform data */ 48 u32 speed_hz; 49 unsigned fifo_size; 50 unsigned int msg_type_shift; 51 unsigned int msg_ctl_width; 52 53 /* Data buffers */ 54 const unsigned char *tx_ptr; 55 unsigned char *rx_ptr; 56 57 /* data iomem */ 58 u8 __iomem *tx_io; 59 const u8 __iomem *rx_io; 60 61 int remaining_bytes; 62 63 struct clk *clk; 64 struct platform_device *pdev; 65 }; 66 67 static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs, 68 unsigned int offset) 69 { 70 return bcm_readb(bs->regs + bcm63xx_spireg(offset)); 71 } 72 73 static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs, 74 unsigned int offset) 75 { 76 return bcm_readw(bs->regs + bcm63xx_spireg(offset)); 77 } 78 79 static inline void bcm_spi_writeb(struct bcm63xx_spi *bs, 80 u8 value, unsigned int offset) 81 { 82 bcm_writeb(value, bs->regs + bcm63xx_spireg(offset)); 83 } 84 85 static inline void bcm_spi_writew(struct bcm63xx_spi *bs, 86 u16 value, unsigned int offset) 87 { 88 bcm_writew(value, bs->regs + bcm63xx_spireg(offset)); 89 } 90 91 static const unsigned bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = { 92 { 20000000, SPI_CLK_20MHZ }, 93 { 12500000, SPI_CLK_12_50MHZ }, 94 { 6250000, SPI_CLK_6_250MHZ }, 95 { 3125000, SPI_CLK_3_125MHZ }, 96 { 1563000, SPI_CLK_1_563MHZ }, 97 { 781000, SPI_CLK_0_781MHZ }, 98 { 391000, SPI_CLK_0_391MHZ } 99 }; 100 101 static int bcm63xx_spi_check_transfer(struct spi_device *spi, 102 struct spi_transfer *t) 103 { 104 u8 bits_per_word; 105 106 bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word; 107 if (bits_per_word != 8) { 108 dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n", 109 __func__, bits_per_word); 110 return -EINVAL; 111 } 112 113 if (spi->chip_select > spi->master->num_chipselect) { 114 dev_err(&spi->dev, "%s, unsupported slave %d\n", 115 __func__, spi->chip_select); 116 return -EINVAL; 117 } 118 119 return 0; 120 } 121 122 static void bcm63xx_spi_setup_transfer(struct spi_device *spi, 123 struct spi_transfer *t) 124 { 125 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); 126 u32 hz; 127 u8 clk_cfg, reg; 128 int i; 129 130 hz = (t) ? t->speed_hz : spi->max_speed_hz; 131 132 /* Find the closest clock configuration */ 133 for (i = 0; i < SPI_CLK_MASK; i++) { 134 if (hz >= bcm63xx_spi_freq_table[i][0]) { 135 clk_cfg = bcm63xx_spi_freq_table[i][1]; 136 break; 137 } 138 } 139 140 /* No matching configuration found, default to lowest */ 141 if (i == SPI_CLK_MASK) 142 clk_cfg = SPI_CLK_0_391MHZ; 143 144 /* clear existing clock configuration bits of the register */ 145 reg = bcm_spi_readb(bs, SPI_CLK_CFG); 146 reg &= ~SPI_CLK_MASK; 147 reg |= clk_cfg; 148 149 bcm_spi_writeb(bs, reg, SPI_CLK_CFG); 150 dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n", 151 clk_cfg, hz); 152 } 153 154 /* the spi->mode bits understood by this driver: */ 155 #define MODEBITS (SPI_CPOL | SPI_CPHA) 156 157 static int bcm63xx_spi_setup(struct spi_device *spi) 158 { 159 struct bcm63xx_spi *bs; 160 int ret; 161 162 bs = spi_master_get_devdata(spi->master); 163 164 if (!spi->bits_per_word) 165 spi->bits_per_word = 8; 166 167 if (spi->mode & ~MODEBITS) { 168 dev_err(&spi->dev, "%s, unsupported mode bits %x\n", 169 __func__, spi->mode & ~MODEBITS); 170 return -EINVAL; 171 } 172 173 ret = bcm63xx_spi_check_transfer(spi, NULL); 174 if (ret < 0) { 175 dev_err(&spi->dev, "setup: unsupported mode bits %x\n", 176 spi->mode & ~MODEBITS); 177 return ret; 178 } 179 180 dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n", 181 __func__, spi->mode & MODEBITS, spi->bits_per_word, 0); 182 183 return 0; 184 } 185 186 /* Fill the TX FIFO with as many bytes as possible */ 187 static void bcm63xx_spi_fill_tx_fifo(struct bcm63xx_spi *bs) 188 { 189 u8 size; 190 191 /* Fill the Tx FIFO with as many bytes as possible */ 192 size = bs->remaining_bytes < bs->fifo_size ? bs->remaining_bytes : 193 bs->fifo_size; 194 memcpy_toio(bs->tx_io, bs->tx_ptr, size); 195 bs->remaining_bytes -= size; 196 } 197 198 static unsigned int bcm63xx_txrx_bufs(struct spi_device *spi, 199 struct spi_transfer *t) 200 { 201 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); 202 u16 msg_ctl; 203 u16 cmd; 204 205 /* Disable the CMD_DONE interrupt */ 206 bcm_spi_writeb(bs, 0, SPI_INT_MASK); 207 208 dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n", 209 t->tx_buf, t->rx_buf, t->len); 210 211 /* Transmitter is inhibited */ 212 bs->tx_ptr = t->tx_buf; 213 bs->rx_ptr = t->rx_buf; 214 215 if (t->tx_buf) { 216 bs->remaining_bytes = t->len; 217 bcm63xx_spi_fill_tx_fifo(bs); 218 } 219 220 init_completion(&bs->done); 221 222 /* Fill in the Message control register */ 223 msg_ctl = (t->len << SPI_BYTE_CNT_SHIFT); 224 225 if (t->rx_buf && t->tx_buf) 226 msg_ctl |= (SPI_FD_RW << bs->msg_type_shift); 227 else if (t->rx_buf) 228 msg_ctl |= (SPI_HD_R << bs->msg_type_shift); 229 else if (t->tx_buf) 230 msg_ctl |= (SPI_HD_W << bs->msg_type_shift); 231 232 switch (bs->msg_ctl_width) { 233 case 8: 234 bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL); 235 break; 236 case 16: 237 bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL); 238 break; 239 } 240 241 /* Issue the transfer */ 242 cmd = SPI_CMD_START_IMMEDIATE; 243 cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT); 244 cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT); 245 bcm_spi_writew(bs, cmd, SPI_CMD); 246 247 /* Enable the CMD_DONE interrupt */ 248 bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK); 249 250 return t->len - bs->remaining_bytes; 251 } 252 253 static int bcm63xx_spi_prepare_transfer(struct spi_master *master) 254 { 255 struct bcm63xx_spi *bs = spi_master_get_devdata(master); 256 257 pm_runtime_get_sync(&bs->pdev->dev); 258 259 return 0; 260 } 261 262 static int bcm63xx_spi_unprepare_transfer(struct spi_master *master) 263 { 264 struct bcm63xx_spi *bs = spi_master_get_devdata(master); 265 266 pm_runtime_put(&bs->pdev->dev); 267 268 return 0; 269 } 270 271 static int bcm63xx_spi_transfer_one(struct spi_master *master, 272 struct spi_message *m) 273 { 274 struct bcm63xx_spi *bs = spi_master_get_devdata(master); 275 struct spi_transfer *t; 276 struct spi_device *spi = m->spi; 277 int status = 0; 278 unsigned int timeout = 0; 279 280 list_for_each_entry(t, &m->transfers, transfer_list) { 281 unsigned int len = t->len; 282 u8 rx_tail; 283 284 status = bcm63xx_spi_check_transfer(spi, t); 285 if (status < 0) 286 goto exit; 287 288 /* configure adapter for a new transfer */ 289 bcm63xx_spi_setup_transfer(spi, t); 290 291 while (len) { 292 /* send the data */ 293 len -= bcm63xx_txrx_bufs(spi, t); 294 295 timeout = wait_for_completion_timeout(&bs->done, HZ); 296 if (!timeout) { 297 status = -ETIMEDOUT; 298 goto exit; 299 } 300 301 /* read out all data */ 302 rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL); 303 304 /* Read out all the data */ 305 if (rx_tail) 306 memcpy_fromio(bs->rx_ptr, bs->rx_io, rx_tail); 307 } 308 309 m->actual_length += t->len; 310 } 311 exit: 312 m->status = status; 313 spi_finalize_current_message(master); 314 315 return 0; 316 } 317 318 /* This driver supports single master mode only. Hence 319 * CMD_DONE is the only interrupt we care about 320 */ 321 static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id) 322 { 323 struct spi_master *master = (struct spi_master *)dev_id; 324 struct bcm63xx_spi *bs = spi_master_get_devdata(master); 325 u8 intr; 326 327 /* Read interupts and clear them immediately */ 328 intr = bcm_spi_readb(bs, SPI_INT_STATUS); 329 bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS); 330 bcm_spi_writeb(bs, 0, SPI_INT_MASK); 331 332 /* A transfer completed */ 333 if (intr & SPI_INTR_CMD_DONE) 334 complete(&bs->done); 335 336 return IRQ_HANDLED; 337 } 338 339 340 static int __devinit bcm63xx_spi_probe(struct platform_device *pdev) 341 { 342 struct resource *r; 343 struct device *dev = &pdev->dev; 344 struct bcm63xx_spi_pdata *pdata = pdev->dev.platform_data; 345 int irq; 346 struct spi_master *master; 347 struct clk *clk; 348 struct bcm63xx_spi *bs; 349 int ret; 350 351 r = platform_get_resource(pdev, IORESOURCE_MEM, 0); 352 if (!r) { 353 dev_err(dev, "no iomem\n"); 354 ret = -ENXIO; 355 goto out; 356 } 357 358 irq = platform_get_irq(pdev, 0); 359 if (irq < 0) { 360 dev_err(dev, "no irq\n"); 361 ret = -ENXIO; 362 goto out; 363 } 364 365 clk = clk_get(dev, "spi"); 366 if (IS_ERR(clk)) { 367 dev_err(dev, "no clock for device\n"); 368 ret = PTR_ERR(clk); 369 goto out; 370 } 371 372 master = spi_alloc_master(dev, sizeof(*bs)); 373 if (!master) { 374 dev_err(dev, "out of memory\n"); 375 ret = -ENOMEM; 376 goto out_clk; 377 } 378 379 bs = spi_master_get_devdata(master); 380 381 platform_set_drvdata(pdev, master); 382 bs->pdev = pdev; 383 384 if (!devm_request_mem_region(&pdev->dev, r->start, 385 resource_size(r), PFX)) { 386 dev_err(dev, "iomem request failed\n"); 387 ret = -ENXIO; 388 goto out_err; 389 } 390 391 bs->regs = devm_ioremap_nocache(&pdev->dev, r->start, 392 resource_size(r)); 393 if (!bs->regs) { 394 dev_err(dev, "unable to ioremap regs\n"); 395 ret = -ENOMEM; 396 goto out_err; 397 } 398 399 bs->irq = irq; 400 bs->clk = clk; 401 bs->fifo_size = pdata->fifo_size; 402 403 ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0, 404 pdev->name, master); 405 if (ret) { 406 dev_err(dev, "unable to request irq\n"); 407 goto out_err; 408 } 409 410 master->bus_num = pdata->bus_num; 411 master->num_chipselect = pdata->num_chipselect; 412 master->setup = bcm63xx_spi_setup; 413 master->prepare_transfer_hardware = bcm63xx_spi_prepare_transfer; 414 master->unprepare_transfer_hardware = bcm63xx_spi_unprepare_transfer; 415 master->transfer_one_message = bcm63xx_spi_transfer_one; 416 master->mode_bits = MODEBITS; 417 bs->speed_hz = pdata->speed_hz; 418 bs->msg_type_shift = pdata->msg_type_shift; 419 bs->msg_ctl_width = pdata->msg_ctl_width; 420 bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA)); 421 bs->rx_io = (const u8 *)(bs->regs + bcm63xx_spireg(SPI_RX_DATA)); 422 423 switch (bs->msg_ctl_width) { 424 case 8: 425 case 16: 426 break; 427 default: 428 dev_err(dev, "unsupported MSG_CTL width: %d\n", 429 bs->msg_ctl_width); 430 goto out_clk_disable; 431 } 432 433 /* Initialize hardware */ 434 clk_enable(bs->clk); 435 bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS); 436 437 /* register and we are done */ 438 ret = spi_register_master(master); 439 if (ret) { 440 dev_err(dev, "spi register failed\n"); 441 goto out_clk_disable; 442 } 443 444 dev_info(dev, "at 0x%08x (irq %d, FIFOs size %d) v%s\n", 445 r->start, irq, bs->fifo_size, DRV_VER); 446 447 return 0; 448 449 out_clk_disable: 450 clk_disable(clk); 451 out_err: 452 platform_set_drvdata(pdev, NULL); 453 spi_master_put(master); 454 out_clk: 455 clk_put(clk); 456 out: 457 return ret; 458 } 459 460 static int __devexit bcm63xx_spi_remove(struct platform_device *pdev) 461 { 462 struct spi_master *master = platform_get_drvdata(pdev); 463 struct bcm63xx_spi *bs = spi_master_get_devdata(master); 464 465 spi_unregister_master(master); 466 467 /* reset spi block */ 468 bcm_spi_writeb(bs, 0, SPI_INT_MASK); 469 470 /* HW shutdown */ 471 clk_disable(bs->clk); 472 clk_put(bs->clk); 473 474 platform_set_drvdata(pdev, 0); 475 476 return 0; 477 } 478 479 #ifdef CONFIG_PM 480 static int bcm63xx_spi_suspend(struct device *dev) 481 { 482 struct spi_master *master = 483 platform_get_drvdata(to_platform_device(dev)); 484 struct bcm63xx_spi *bs = spi_master_get_devdata(master); 485 486 clk_disable(bs->clk); 487 488 return 0; 489 } 490 491 static int bcm63xx_spi_resume(struct device *dev) 492 { 493 struct spi_master *master = 494 platform_get_drvdata(to_platform_device(dev)); 495 struct bcm63xx_spi *bs = spi_master_get_devdata(master); 496 497 clk_enable(bs->clk); 498 499 return 0; 500 } 501 502 static const struct dev_pm_ops bcm63xx_spi_pm_ops = { 503 .suspend = bcm63xx_spi_suspend, 504 .resume = bcm63xx_spi_resume, 505 }; 506 507 #define BCM63XX_SPI_PM_OPS (&bcm63xx_spi_pm_ops) 508 #else 509 #define BCM63XX_SPI_PM_OPS NULL 510 #endif 511 512 static struct platform_driver bcm63xx_spi_driver = { 513 .driver = { 514 .name = "bcm63xx-spi", 515 .owner = THIS_MODULE, 516 .pm = BCM63XX_SPI_PM_OPS, 517 }, 518 .probe = bcm63xx_spi_probe, 519 .remove = __devexit_p(bcm63xx_spi_remove), 520 }; 521 522 module_platform_driver(bcm63xx_spi_driver); 523 524 MODULE_ALIAS("platform:bcm63xx_spi"); 525 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); 526 MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>"); 527 MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver"); 528 MODULE_LICENSE("GPL"); 529