1 /* 2 * Broadcom BCM63XX High Speed SPI Controller driver 3 * 4 * Copyright 2000-2010 Broadcom Corporation 5 * Copyright 2012-2013 Jonas Gorski <jogo@openwrt.org> 6 * 7 * Licensed under the GNU/GPL. See COPYING for details. 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/init.h> 12 #include <linux/io.h> 13 #include <linux/clk.h> 14 #include <linux/module.h> 15 #include <linux/platform_device.h> 16 #include <linux/delay.h> 17 #include <linux/dma-mapping.h> 18 #include <linux/err.h> 19 #include <linux/interrupt.h> 20 #include <linux/spi/spi.h> 21 #include <linux/mutex.h> 22 #include <linux/of.h> 23 24 #define HSSPI_GLOBAL_CTRL_REG 0x0 25 #define GLOBAL_CTRL_CS_POLARITY_SHIFT 0 26 #define GLOBAL_CTRL_CS_POLARITY_MASK 0x000000ff 27 #define GLOBAL_CTRL_PLL_CLK_CTRL_SHIFT 8 28 #define GLOBAL_CTRL_PLL_CLK_CTRL_MASK 0x0000ff00 29 #define GLOBAL_CTRL_CLK_GATE_SSOFF BIT(16) 30 #define GLOBAL_CTRL_CLK_POLARITY BIT(17) 31 #define GLOBAL_CTRL_MOSI_IDLE BIT(18) 32 33 #define HSSPI_GLOBAL_EXT_TRIGGER_REG 0x4 34 35 #define HSSPI_INT_STATUS_REG 0x8 36 #define HSSPI_INT_STATUS_MASKED_REG 0xc 37 #define HSSPI_INT_MASK_REG 0x10 38 39 #define HSSPI_PINGx_CMD_DONE(i) BIT((i * 8) + 0) 40 #define HSSPI_PINGx_RX_OVER(i) BIT((i * 8) + 1) 41 #define HSSPI_PINGx_TX_UNDER(i) BIT((i * 8) + 2) 42 #define HSSPI_PINGx_POLL_TIMEOUT(i) BIT((i * 8) + 3) 43 #define HSSPI_PINGx_CTRL_INVAL(i) BIT((i * 8) + 4) 44 45 #define HSSPI_INT_CLEAR_ALL 0xff001f1f 46 47 #define HSSPI_PINGPONG_COMMAND_REG(x) (0x80 + (x) * 0x40) 48 #define PINGPONG_CMD_COMMAND_MASK 0xf 49 #define PINGPONG_COMMAND_NOOP 0 50 #define PINGPONG_COMMAND_START_NOW 1 51 #define PINGPONG_COMMAND_START_TRIGGER 2 52 #define PINGPONG_COMMAND_HALT 3 53 #define PINGPONG_COMMAND_FLUSH 4 54 #define PINGPONG_CMD_PROFILE_SHIFT 8 55 #define PINGPONG_CMD_SS_SHIFT 12 56 57 #define HSSPI_PINGPONG_STATUS_REG(x) (0x84 + (x) * 0x40) 58 59 #define HSSPI_PROFILE_CLK_CTRL_REG(x) (0x100 + (x) * 0x20) 60 #define CLK_CTRL_FREQ_CTRL_MASK 0x0000ffff 61 #define CLK_CTRL_SPI_CLK_2X_SEL BIT(14) 62 #define CLK_CTRL_ACCUM_RST_ON_LOOP BIT(15) 63 64 #define HSSPI_PROFILE_SIGNAL_CTRL_REG(x) (0x104 + (x) * 0x20) 65 #define SIGNAL_CTRL_LATCH_RISING BIT(12) 66 #define SIGNAL_CTRL_LAUNCH_RISING BIT(13) 67 #define SIGNAL_CTRL_ASYNC_INPUT_PATH BIT(16) 68 69 #define HSSPI_PROFILE_MODE_CTRL_REG(x) (0x108 + (x) * 0x20) 70 #define MODE_CTRL_MULTIDATA_RD_STRT_SHIFT 8 71 #define MODE_CTRL_MULTIDATA_WR_STRT_SHIFT 12 72 #define MODE_CTRL_MULTIDATA_RD_SIZE_SHIFT 16 73 #define MODE_CTRL_MULTIDATA_WR_SIZE_SHIFT 18 74 #define MODE_CTRL_MODE_3WIRE BIT(20) 75 #define MODE_CTRL_PREPENDBYTE_CNT_SHIFT 24 76 77 #define HSSPI_FIFO_REG(x) (0x200 + (x) * 0x200) 78 79 80 #define HSSPI_OP_MULTIBIT BIT(11) 81 #define HSSPI_OP_CODE_SHIFT 13 82 #define HSSPI_OP_SLEEP (0 << HSSPI_OP_CODE_SHIFT) 83 #define HSSPI_OP_READ_WRITE (1 << HSSPI_OP_CODE_SHIFT) 84 #define HSSPI_OP_WRITE (2 << HSSPI_OP_CODE_SHIFT) 85 #define HSSPI_OP_READ (3 << HSSPI_OP_CODE_SHIFT) 86 #define HSSPI_OP_SETIRQ (4 << HSSPI_OP_CODE_SHIFT) 87 88 #define HSSPI_BUFFER_LEN 512 89 #define HSSPI_OPCODE_LEN 2 90 91 #define HSSPI_MAX_PREPEND_LEN 15 92 93 #define HSSPI_MAX_SYNC_CLOCK 30000000 94 95 #define HSSPI_SPI_MAX_CS 8 96 #define HSSPI_BUS_NUM 1 /* 0 is legacy SPI */ 97 98 struct bcm63xx_hsspi { 99 struct completion done; 100 struct mutex bus_mutex; 101 102 struct platform_device *pdev; 103 struct clk *clk; 104 struct clk *pll_clk; 105 void __iomem *regs; 106 u8 __iomem *fifo; 107 108 u32 speed_hz; 109 u8 cs_polarity; 110 }; 111 112 static void bcm63xx_hsspi_set_cs(struct bcm63xx_hsspi *bs, unsigned int cs, 113 bool active) 114 { 115 u32 reg; 116 117 mutex_lock(&bs->bus_mutex); 118 reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG); 119 120 reg &= ~BIT(cs); 121 if (active == !(bs->cs_polarity & BIT(cs))) 122 reg |= BIT(cs); 123 124 __raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG); 125 mutex_unlock(&bs->bus_mutex); 126 } 127 128 static void bcm63xx_hsspi_set_clk(struct bcm63xx_hsspi *bs, 129 struct spi_device *spi, int hz) 130 { 131 unsigned int profile = spi->chip_select; 132 u32 reg; 133 134 reg = DIV_ROUND_UP(2048, DIV_ROUND_UP(bs->speed_hz, hz)); 135 __raw_writel(CLK_CTRL_ACCUM_RST_ON_LOOP | reg, 136 bs->regs + HSSPI_PROFILE_CLK_CTRL_REG(profile)); 137 138 reg = __raw_readl(bs->regs + HSSPI_PROFILE_SIGNAL_CTRL_REG(profile)); 139 if (hz > HSSPI_MAX_SYNC_CLOCK) 140 reg |= SIGNAL_CTRL_ASYNC_INPUT_PATH; 141 else 142 reg &= ~SIGNAL_CTRL_ASYNC_INPUT_PATH; 143 __raw_writel(reg, bs->regs + HSSPI_PROFILE_SIGNAL_CTRL_REG(profile)); 144 145 mutex_lock(&bs->bus_mutex); 146 /* setup clock polarity */ 147 reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG); 148 reg &= ~GLOBAL_CTRL_CLK_POLARITY; 149 if (spi->mode & SPI_CPOL) 150 reg |= GLOBAL_CTRL_CLK_POLARITY; 151 __raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG); 152 mutex_unlock(&bs->bus_mutex); 153 } 154 155 static int bcm63xx_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t) 156 { 157 struct bcm63xx_hsspi *bs = spi_master_get_devdata(spi->master); 158 unsigned int chip_select = spi->chip_select; 159 u16 opcode = 0; 160 int pending = t->len; 161 int step_size = HSSPI_BUFFER_LEN; 162 const u8 *tx = t->tx_buf; 163 u8 *rx = t->rx_buf; 164 165 bcm63xx_hsspi_set_clk(bs, spi, t->speed_hz); 166 bcm63xx_hsspi_set_cs(bs, spi->chip_select, true); 167 168 if (tx && rx) 169 opcode = HSSPI_OP_READ_WRITE; 170 else if (tx) 171 opcode = HSSPI_OP_WRITE; 172 else if (rx) 173 opcode = HSSPI_OP_READ; 174 175 if (opcode != HSSPI_OP_READ) 176 step_size -= HSSPI_OPCODE_LEN; 177 178 if ((opcode == HSSPI_OP_READ && t->rx_nbits == SPI_NBITS_DUAL) || 179 (opcode == HSSPI_OP_WRITE && t->tx_nbits == SPI_NBITS_DUAL)) 180 opcode |= HSSPI_OP_MULTIBIT; 181 182 __raw_writel(1 << MODE_CTRL_MULTIDATA_WR_SIZE_SHIFT | 183 1 << MODE_CTRL_MULTIDATA_RD_SIZE_SHIFT | 0xff, 184 bs->regs + HSSPI_PROFILE_MODE_CTRL_REG(chip_select)); 185 186 while (pending > 0) { 187 int curr_step = min_t(int, step_size, pending); 188 189 reinit_completion(&bs->done); 190 if (tx) { 191 memcpy_toio(bs->fifo + HSSPI_OPCODE_LEN, tx, curr_step); 192 tx += curr_step; 193 } 194 195 __raw_writew(opcode | curr_step, bs->fifo); 196 197 /* enable interrupt */ 198 __raw_writel(HSSPI_PINGx_CMD_DONE(0), 199 bs->regs + HSSPI_INT_MASK_REG); 200 201 /* start the transfer */ 202 __raw_writel(!chip_select << PINGPONG_CMD_SS_SHIFT | 203 chip_select << PINGPONG_CMD_PROFILE_SHIFT | 204 PINGPONG_COMMAND_START_NOW, 205 bs->regs + HSSPI_PINGPONG_COMMAND_REG(0)); 206 207 if (wait_for_completion_timeout(&bs->done, HZ) == 0) { 208 dev_err(&bs->pdev->dev, "transfer timed out!\n"); 209 return -ETIMEDOUT; 210 } 211 212 if (rx) { 213 memcpy_fromio(rx, bs->fifo, curr_step); 214 rx += curr_step; 215 } 216 217 pending -= curr_step; 218 } 219 220 return 0; 221 } 222 223 static int bcm63xx_hsspi_setup(struct spi_device *spi) 224 { 225 struct bcm63xx_hsspi *bs = spi_master_get_devdata(spi->master); 226 u32 reg; 227 228 reg = __raw_readl(bs->regs + 229 HSSPI_PROFILE_SIGNAL_CTRL_REG(spi->chip_select)); 230 reg &= ~(SIGNAL_CTRL_LAUNCH_RISING | SIGNAL_CTRL_LATCH_RISING); 231 if (spi->mode & SPI_CPHA) 232 reg |= SIGNAL_CTRL_LAUNCH_RISING; 233 else 234 reg |= SIGNAL_CTRL_LATCH_RISING; 235 __raw_writel(reg, bs->regs + 236 HSSPI_PROFILE_SIGNAL_CTRL_REG(spi->chip_select)); 237 238 mutex_lock(&bs->bus_mutex); 239 reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG); 240 241 /* only change actual polarities if there is no transfer */ 242 if ((reg & GLOBAL_CTRL_CS_POLARITY_MASK) == bs->cs_polarity) { 243 if (spi->mode & SPI_CS_HIGH) 244 reg |= BIT(spi->chip_select); 245 else 246 reg &= ~BIT(spi->chip_select); 247 __raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG); 248 } 249 250 if (spi->mode & SPI_CS_HIGH) 251 bs->cs_polarity |= BIT(spi->chip_select); 252 else 253 bs->cs_polarity &= ~BIT(spi->chip_select); 254 255 mutex_unlock(&bs->bus_mutex); 256 257 return 0; 258 } 259 260 static int bcm63xx_hsspi_transfer_one(struct spi_master *master, 261 struct spi_message *msg) 262 { 263 struct bcm63xx_hsspi *bs = spi_master_get_devdata(master); 264 struct spi_transfer *t; 265 struct spi_device *spi = msg->spi; 266 int status = -EINVAL; 267 int dummy_cs; 268 u32 reg; 269 270 /* This controller does not support keeping CS active during idle. 271 * To work around this, we use the following ugly hack: 272 * 273 * a. Invert the target chip select's polarity so it will be active. 274 * b. Select a "dummy" chip select to use as the hardware target. 275 * c. Invert the dummy chip select's polarity so it will be inactive 276 * during the actual transfers. 277 * d. Tell the hardware to send to the dummy chip select. Thanks to 278 * the multiplexed nature of SPI the actual target will receive 279 * the transfer and we see its response. 280 * 281 * e. At the end restore the polarities again to their default values. 282 */ 283 284 dummy_cs = !spi->chip_select; 285 bcm63xx_hsspi_set_cs(bs, dummy_cs, true); 286 287 list_for_each_entry(t, &msg->transfers, transfer_list) { 288 status = bcm63xx_hsspi_do_txrx(spi, t); 289 if (status) 290 break; 291 292 msg->actual_length += t->len; 293 294 spi_transfer_delay_exec(t); 295 296 if (t->cs_change) 297 bcm63xx_hsspi_set_cs(bs, spi->chip_select, false); 298 } 299 300 mutex_lock(&bs->bus_mutex); 301 reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG); 302 reg &= ~GLOBAL_CTRL_CS_POLARITY_MASK; 303 reg |= bs->cs_polarity; 304 __raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG); 305 mutex_unlock(&bs->bus_mutex); 306 307 msg->status = status; 308 spi_finalize_current_message(master); 309 310 return 0; 311 } 312 313 static irqreturn_t bcm63xx_hsspi_interrupt(int irq, void *dev_id) 314 { 315 struct bcm63xx_hsspi *bs = (struct bcm63xx_hsspi *)dev_id; 316 317 if (__raw_readl(bs->regs + HSSPI_INT_STATUS_MASKED_REG) == 0) 318 return IRQ_NONE; 319 320 __raw_writel(HSSPI_INT_CLEAR_ALL, bs->regs + HSSPI_INT_STATUS_REG); 321 __raw_writel(0, bs->regs + HSSPI_INT_MASK_REG); 322 323 complete(&bs->done); 324 325 return IRQ_HANDLED; 326 } 327 328 static int bcm63xx_hsspi_probe(struct platform_device *pdev) 329 { 330 struct spi_master *master; 331 struct bcm63xx_hsspi *bs; 332 void __iomem *regs; 333 struct device *dev = &pdev->dev; 334 struct clk *clk, *pll_clk = NULL; 335 int irq, ret; 336 u32 reg, rate, num_cs = HSSPI_SPI_MAX_CS; 337 338 irq = platform_get_irq(pdev, 0); 339 if (irq < 0) 340 return irq; 341 342 regs = devm_platform_ioremap_resource(pdev, 0); 343 if (IS_ERR(regs)) 344 return PTR_ERR(regs); 345 346 clk = devm_clk_get(dev, "hsspi"); 347 348 if (IS_ERR(clk)) 349 return PTR_ERR(clk); 350 351 ret = clk_prepare_enable(clk); 352 if (ret) 353 return ret; 354 355 rate = clk_get_rate(clk); 356 if (!rate) { 357 pll_clk = devm_clk_get(dev, "pll"); 358 359 if (IS_ERR(pll_clk)) { 360 ret = PTR_ERR(pll_clk); 361 goto out_disable_clk; 362 } 363 364 ret = clk_prepare_enable(pll_clk); 365 if (ret) 366 goto out_disable_clk; 367 368 rate = clk_get_rate(pll_clk); 369 if (!rate) { 370 ret = -EINVAL; 371 goto out_disable_pll_clk; 372 } 373 } 374 375 master = spi_alloc_master(&pdev->dev, sizeof(*bs)); 376 if (!master) { 377 ret = -ENOMEM; 378 goto out_disable_pll_clk; 379 } 380 381 bs = spi_master_get_devdata(master); 382 bs->pdev = pdev; 383 bs->clk = clk; 384 bs->pll_clk = pll_clk; 385 bs->regs = regs; 386 bs->speed_hz = rate; 387 bs->fifo = (u8 __iomem *)(bs->regs + HSSPI_FIFO_REG(0)); 388 389 mutex_init(&bs->bus_mutex); 390 init_completion(&bs->done); 391 392 master->dev.of_node = dev->of_node; 393 if (!dev->of_node) 394 master->bus_num = HSSPI_BUS_NUM; 395 396 of_property_read_u32(dev->of_node, "num-cs", &num_cs); 397 if (num_cs > 8) { 398 dev_warn(dev, "unsupported number of cs (%i), reducing to 8\n", 399 num_cs); 400 num_cs = HSSPI_SPI_MAX_CS; 401 } 402 master->num_chipselect = num_cs; 403 master->setup = bcm63xx_hsspi_setup; 404 master->transfer_one_message = bcm63xx_hsspi_transfer_one; 405 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | 406 SPI_RX_DUAL | SPI_TX_DUAL; 407 master->bits_per_word_mask = SPI_BPW_MASK(8); 408 master->auto_runtime_pm = true; 409 410 platform_set_drvdata(pdev, master); 411 412 /* Initialize the hardware */ 413 __raw_writel(0, bs->regs + HSSPI_INT_MASK_REG); 414 415 /* clean up any pending interrupts */ 416 __raw_writel(HSSPI_INT_CLEAR_ALL, bs->regs + HSSPI_INT_STATUS_REG); 417 418 /* read out default CS polarities */ 419 reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG); 420 bs->cs_polarity = reg & GLOBAL_CTRL_CS_POLARITY_MASK; 421 __raw_writel(reg | GLOBAL_CTRL_CLK_GATE_SSOFF, 422 bs->regs + HSSPI_GLOBAL_CTRL_REG); 423 424 ret = devm_request_irq(dev, irq, bcm63xx_hsspi_interrupt, IRQF_SHARED, 425 pdev->name, bs); 426 427 if (ret) 428 goto out_put_master; 429 430 /* register and we are done */ 431 ret = devm_spi_register_master(dev, master); 432 if (ret) 433 goto out_put_master; 434 435 return 0; 436 437 out_put_master: 438 spi_master_put(master); 439 out_disable_pll_clk: 440 clk_disable_unprepare(pll_clk); 441 out_disable_clk: 442 clk_disable_unprepare(clk); 443 return ret; 444 } 445 446 447 static int bcm63xx_hsspi_remove(struct platform_device *pdev) 448 { 449 struct spi_master *master = platform_get_drvdata(pdev); 450 struct bcm63xx_hsspi *bs = spi_master_get_devdata(master); 451 452 /* reset the hardware and block queue progress */ 453 __raw_writel(0, bs->regs + HSSPI_INT_MASK_REG); 454 clk_disable_unprepare(bs->pll_clk); 455 clk_disable_unprepare(bs->clk); 456 457 return 0; 458 } 459 460 #ifdef CONFIG_PM_SLEEP 461 static int bcm63xx_hsspi_suspend(struct device *dev) 462 { 463 struct spi_master *master = dev_get_drvdata(dev); 464 struct bcm63xx_hsspi *bs = spi_master_get_devdata(master); 465 466 spi_master_suspend(master); 467 clk_disable_unprepare(bs->pll_clk); 468 clk_disable_unprepare(bs->clk); 469 470 return 0; 471 } 472 473 static int bcm63xx_hsspi_resume(struct device *dev) 474 { 475 struct spi_master *master = dev_get_drvdata(dev); 476 struct bcm63xx_hsspi *bs = spi_master_get_devdata(master); 477 int ret; 478 479 ret = clk_prepare_enable(bs->clk); 480 if (ret) 481 return ret; 482 483 if (bs->pll_clk) { 484 ret = clk_prepare_enable(bs->pll_clk); 485 if (ret) 486 return ret; 487 } 488 489 spi_master_resume(master); 490 491 return 0; 492 } 493 #endif 494 495 static SIMPLE_DEV_PM_OPS(bcm63xx_hsspi_pm_ops, bcm63xx_hsspi_suspend, 496 bcm63xx_hsspi_resume); 497 498 static const struct of_device_id bcm63xx_hsspi_of_match[] = { 499 { .compatible = "brcm,bcm6328-hsspi", }, 500 { }, 501 }; 502 MODULE_DEVICE_TABLE(of, bcm63xx_hsspi_of_match); 503 504 static struct platform_driver bcm63xx_hsspi_driver = { 505 .driver = { 506 .name = "bcm63xx-hsspi", 507 .pm = &bcm63xx_hsspi_pm_ops, 508 .of_match_table = bcm63xx_hsspi_of_match, 509 }, 510 .probe = bcm63xx_hsspi_probe, 511 .remove = bcm63xx_hsspi_remove, 512 }; 513 514 module_platform_driver(bcm63xx_hsspi_driver); 515 516 MODULE_ALIAS("platform:bcm63xx_hsspi"); 517 MODULE_DESCRIPTION("Broadcom BCM63xx High Speed SPI Controller driver"); 518 MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>"); 519 MODULE_LICENSE("GPL"); 520