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