1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Driver for AMBA serial ports 4 * 5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. 6 * 7 * Copyright 1999 ARM Limited 8 * Copyright (C) 2000 Deep Blue Solutions Ltd. 9 * Copyright (C) 2010 ST-Ericsson SA 10 * 11 * This is a generic driver for ARM AMBA-type serial ports. They 12 * have a lot of 16550-like features, but are not register compatible. 13 * Note that although they do have CTS, DCD and DSR inputs, they do 14 * not have an RI input, nor do they have DTR or RTS outputs. If 15 * required, these have to be supplied via some other means (eg, GPIO) 16 * and hooked into this driver. 17 */ 18 19 #include <linux/module.h> 20 #include <linux/ioport.h> 21 #include <linux/init.h> 22 #include <linux/console.h> 23 #include <linux/sysrq.h> 24 #include <linux/device.h> 25 #include <linux/tty.h> 26 #include <linux/tty_flip.h> 27 #include <linux/serial_core.h> 28 #include <linux/serial.h> 29 #include <linux/amba/bus.h> 30 #include <linux/amba/serial.h> 31 #include <linux/clk.h> 32 #include <linux/slab.h> 33 #include <linux/dmaengine.h> 34 #include <linux/dma-mapping.h> 35 #include <linux/scatterlist.h> 36 #include <linux/delay.h> 37 #include <linux/types.h> 38 #include <linux/of.h> 39 #include <linux/of_device.h> 40 #include <linux/pinctrl/consumer.h> 41 #include <linux/sizes.h> 42 #include <linux/io.h> 43 #include <linux/acpi.h> 44 45 #include "amba-pl011.h" 46 47 #define UART_NR 14 48 49 #define SERIAL_AMBA_MAJOR 204 50 #define SERIAL_AMBA_MINOR 64 51 #define SERIAL_AMBA_NR UART_NR 52 53 #define AMBA_ISR_PASS_LIMIT 256 54 55 #define UART_DR_ERROR (UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE) 56 #define UART_DUMMY_DR_RX (1 << 16) 57 58 static u16 pl011_std_offsets[REG_ARRAY_SIZE] = { 59 [REG_DR] = UART01x_DR, 60 [REG_FR] = UART01x_FR, 61 [REG_LCRH_RX] = UART011_LCRH, 62 [REG_LCRH_TX] = UART011_LCRH, 63 [REG_IBRD] = UART011_IBRD, 64 [REG_FBRD] = UART011_FBRD, 65 [REG_CR] = UART011_CR, 66 [REG_IFLS] = UART011_IFLS, 67 [REG_IMSC] = UART011_IMSC, 68 [REG_RIS] = UART011_RIS, 69 [REG_MIS] = UART011_MIS, 70 [REG_ICR] = UART011_ICR, 71 [REG_DMACR] = UART011_DMACR, 72 }; 73 74 /* There is by now at least one vendor with differing details, so handle it */ 75 struct vendor_data { 76 const u16 *reg_offset; 77 unsigned int ifls; 78 unsigned int fr_busy; 79 unsigned int fr_dsr; 80 unsigned int fr_cts; 81 unsigned int fr_ri; 82 unsigned int inv_fr; 83 bool access_32b; 84 bool oversampling; 85 bool dma_threshold; 86 bool cts_event_workaround; 87 bool always_enabled; 88 bool fixed_options; 89 90 unsigned int (*get_fifosize)(struct amba_device *dev); 91 }; 92 93 static unsigned int get_fifosize_arm(struct amba_device *dev) 94 { 95 return amba_rev(dev) < 3 ? 16 : 32; 96 } 97 98 static struct vendor_data vendor_arm = { 99 .reg_offset = pl011_std_offsets, 100 .ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8, 101 .fr_busy = UART01x_FR_BUSY, 102 .fr_dsr = UART01x_FR_DSR, 103 .fr_cts = UART01x_FR_CTS, 104 .fr_ri = UART011_FR_RI, 105 .oversampling = false, 106 .dma_threshold = false, 107 .cts_event_workaround = false, 108 .always_enabled = false, 109 .fixed_options = false, 110 .get_fifosize = get_fifosize_arm, 111 }; 112 113 static const struct vendor_data vendor_sbsa = { 114 .reg_offset = pl011_std_offsets, 115 .fr_busy = UART01x_FR_BUSY, 116 .fr_dsr = UART01x_FR_DSR, 117 .fr_cts = UART01x_FR_CTS, 118 .fr_ri = UART011_FR_RI, 119 .access_32b = true, 120 .oversampling = false, 121 .dma_threshold = false, 122 .cts_event_workaround = false, 123 .always_enabled = true, 124 .fixed_options = true, 125 }; 126 127 #ifdef CONFIG_ACPI_SPCR_TABLE 128 static const struct vendor_data vendor_qdt_qdf2400_e44 = { 129 .reg_offset = pl011_std_offsets, 130 .fr_busy = UART011_FR_TXFE, 131 .fr_dsr = UART01x_FR_DSR, 132 .fr_cts = UART01x_FR_CTS, 133 .fr_ri = UART011_FR_RI, 134 .inv_fr = UART011_FR_TXFE, 135 .access_32b = true, 136 .oversampling = false, 137 .dma_threshold = false, 138 .cts_event_workaround = false, 139 .always_enabled = true, 140 .fixed_options = true, 141 }; 142 #endif 143 144 static u16 pl011_st_offsets[REG_ARRAY_SIZE] = { 145 [REG_DR] = UART01x_DR, 146 [REG_ST_DMAWM] = ST_UART011_DMAWM, 147 [REG_ST_TIMEOUT] = ST_UART011_TIMEOUT, 148 [REG_FR] = UART01x_FR, 149 [REG_LCRH_RX] = ST_UART011_LCRH_RX, 150 [REG_LCRH_TX] = ST_UART011_LCRH_TX, 151 [REG_IBRD] = UART011_IBRD, 152 [REG_FBRD] = UART011_FBRD, 153 [REG_CR] = UART011_CR, 154 [REG_IFLS] = UART011_IFLS, 155 [REG_IMSC] = UART011_IMSC, 156 [REG_RIS] = UART011_RIS, 157 [REG_MIS] = UART011_MIS, 158 [REG_ICR] = UART011_ICR, 159 [REG_DMACR] = UART011_DMACR, 160 [REG_ST_XFCR] = ST_UART011_XFCR, 161 [REG_ST_XON1] = ST_UART011_XON1, 162 [REG_ST_XON2] = ST_UART011_XON2, 163 [REG_ST_XOFF1] = ST_UART011_XOFF1, 164 [REG_ST_XOFF2] = ST_UART011_XOFF2, 165 [REG_ST_ITCR] = ST_UART011_ITCR, 166 [REG_ST_ITIP] = ST_UART011_ITIP, 167 [REG_ST_ABCR] = ST_UART011_ABCR, 168 [REG_ST_ABIMSC] = ST_UART011_ABIMSC, 169 }; 170 171 static unsigned int get_fifosize_st(struct amba_device *dev) 172 { 173 return 64; 174 } 175 176 static struct vendor_data vendor_st = { 177 .reg_offset = pl011_st_offsets, 178 .ifls = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF, 179 .fr_busy = UART01x_FR_BUSY, 180 .fr_dsr = UART01x_FR_DSR, 181 .fr_cts = UART01x_FR_CTS, 182 .fr_ri = UART011_FR_RI, 183 .oversampling = true, 184 .dma_threshold = true, 185 .cts_event_workaround = true, 186 .always_enabled = false, 187 .fixed_options = false, 188 .get_fifosize = get_fifosize_st, 189 }; 190 191 static const u16 pl011_zte_offsets[REG_ARRAY_SIZE] = { 192 [REG_DR] = ZX_UART011_DR, 193 [REG_FR] = ZX_UART011_FR, 194 [REG_LCRH_RX] = ZX_UART011_LCRH, 195 [REG_LCRH_TX] = ZX_UART011_LCRH, 196 [REG_IBRD] = ZX_UART011_IBRD, 197 [REG_FBRD] = ZX_UART011_FBRD, 198 [REG_CR] = ZX_UART011_CR, 199 [REG_IFLS] = ZX_UART011_IFLS, 200 [REG_IMSC] = ZX_UART011_IMSC, 201 [REG_RIS] = ZX_UART011_RIS, 202 [REG_MIS] = ZX_UART011_MIS, 203 [REG_ICR] = ZX_UART011_ICR, 204 [REG_DMACR] = ZX_UART011_DMACR, 205 }; 206 207 static unsigned int get_fifosize_zte(struct amba_device *dev) 208 { 209 return 16; 210 } 211 212 static struct vendor_data vendor_zte = { 213 .reg_offset = pl011_zte_offsets, 214 .access_32b = true, 215 .ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8, 216 .fr_busy = ZX_UART01x_FR_BUSY, 217 .fr_dsr = ZX_UART01x_FR_DSR, 218 .fr_cts = ZX_UART01x_FR_CTS, 219 .fr_ri = ZX_UART011_FR_RI, 220 .get_fifosize = get_fifosize_zte, 221 }; 222 223 /* Deals with DMA transactions */ 224 225 struct pl011_sgbuf { 226 struct scatterlist sg; 227 char *buf; 228 }; 229 230 struct pl011_dmarx_data { 231 struct dma_chan *chan; 232 struct completion complete; 233 bool use_buf_b; 234 struct pl011_sgbuf sgbuf_a; 235 struct pl011_sgbuf sgbuf_b; 236 dma_cookie_t cookie; 237 bool running; 238 struct timer_list timer; 239 unsigned int last_residue; 240 unsigned long last_jiffies; 241 bool auto_poll_rate; 242 unsigned int poll_rate; 243 unsigned int poll_timeout; 244 }; 245 246 struct pl011_dmatx_data { 247 struct dma_chan *chan; 248 struct scatterlist sg; 249 char *buf; 250 bool queued; 251 }; 252 253 /* 254 * We wrap our port structure around the generic uart_port. 255 */ 256 struct uart_amba_port { 257 struct uart_port port; 258 const u16 *reg_offset; 259 struct clk *clk; 260 const struct vendor_data *vendor; 261 unsigned int dmacr; /* dma control reg */ 262 unsigned int im; /* interrupt mask */ 263 unsigned int old_status; 264 unsigned int fifosize; /* vendor-specific */ 265 unsigned int old_cr; /* state during shutdown */ 266 unsigned int fixed_baud; /* vendor-set fixed baud rate */ 267 char type[12]; 268 #ifdef CONFIG_DMA_ENGINE 269 /* DMA stuff */ 270 bool using_tx_dma; 271 bool using_rx_dma; 272 struct pl011_dmarx_data dmarx; 273 struct pl011_dmatx_data dmatx; 274 bool dma_probed; 275 #endif 276 }; 277 278 static unsigned int pl011_reg_to_offset(const struct uart_amba_port *uap, 279 unsigned int reg) 280 { 281 return uap->reg_offset[reg]; 282 } 283 284 static unsigned int pl011_read(const struct uart_amba_port *uap, 285 unsigned int reg) 286 { 287 void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg); 288 289 return (uap->port.iotype == UPIO_MEM32) ? 290 readl_relaxed(addr) : readw_relaxed(addr); 291 } 292 293 static void pl011_write(unsigned int val, const struct uart_amba_port *uap, 294 unsigned int reg) 295 { 296 void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg); 297 298 if (uap->port.iotype == UPIO_MEM32) 299 writel_relaxed(val, addr); 300 else 301 writew_relaxed(val, addr); 302 } 303 304 /* 305 * Reads up to 256 characters from the FIFO or until it's empty and 306 * inserts them into the TTY layer. Returns the number of characters 307 * read from the FIFO. 308 */ 309 static int pl011_fifo_to_tty(struct uart_amba_port *uap) 310 { 311 u16 status; 312 unsigned int ch, flag, fifotaken; 313 314 for (fifotaken = 0; fifotaken != 256; fifotaken++) { 315 status = pl011_read(uap, REG_FR); 316 if (status & UART01x_FR_RXFE) 317 break; 318 319 /* Take chars from the FIFO and update status */ 320 ch = pl011_read(uap, REG_DR) | UART_DUMMY_DR_RX; 321 flag = TTY_NORMAL; 322 uap->port.icount.rx++; 323 324 if (unlikely(ch & UART_DR_ERROR)) { 325 if (ch & UART011_DR_BE) { 326 ch &= ~(UART011_DR_FE | UART011_DR_PE); 327 uap->port.icount.brk++; 328 if (uart_handle_break(&uap->port)) 329 continue; 330 } else if (ch & UART011_DR_PE) 331 uap->port.icount.parity++; 332 else if (ch & UART011_DR_FE) 333 uap->port.icount.frame++; 334 if (ch & UART011_DR_OE) 335 uap->port.icount.overrun++; 336 337 ch &= uap->port.read_status_mask; 338 339 if (ch & UART011_DR_BE) 340 flag = TTY_BREAK; 341 else if (ch & UART011_DR_PE) 342 flag = TTY_PARITY; 343 else if (ch & UART011_DR_FE) 344 flag = TTY_FRAME; 345 } 346 347 if (uart_handle_sysrq_char(&uap->port, ch & 255)) 348 continue; 349 350 uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag); 351 } 352 353 return fifotaken; 354 } 355 356 357 /* 358 * All the DMA operation mode stuff goes inside this ifdef. 359 * This assumes that you have a generic DMA device interface, 360 * no custom DMA interfaces are supported. 361 */ 362 #ifdef CONFIG_DMA_ENGINE 363 364 #define PL011_DMA_BUFFER_SIZE PAGE_SIZE 365 366 static int pl011_sgbuf_init(struct dma_chan *chan, struct pl011_sgbuf *sg, 367 enum dma_data_direction dir) 368 { 369 dma_addr_t dma_addr; 370 371 sg->buf = dma_alloc_coherent(chan->device->dev, 372 PL011_DMA_BUFFER_SIZE, &dma_addr, GFP_KERNEL); 373 if (!sg->buf) 374 return -ENOMEM; 375 376 sg_init_table(&sg->sg, 1); 377 sg_set_page(&sg->sg, phys_to_page(dma_addr), 378 PL011_DMA_BUFFER_SIZE, offset_in_page(dma_addr)); 379 sg_dma_address(&sg->sg) = dma_addr; 380 sg_dma_len(&sg->sg) = PL011_DMA_BUFFER_SIZE; 381 382 return 0; 383 } 384 385 static void pl011_sgbuf_free(struct dma_chan *chan, struct pl011_sgbuf *sg, 386 enum dma_data_direction dir) 387 { 388 if (sg->buf) { 389 dma_free_coherent(chan->device->dev, 390 PL011_DMA_BUFFER_SIZE, sg->buf, 391 sg_dma_address(&sg->sg)); 392 } 393 } 394 395 static void pl011_dma_probe(struct uart_amba_port *uap) 396 { 397 /* DMA is the sole user of the platform data right now */ 398 struct amba_pl011_data *plat = dev_get_platdata(uap->port.dev); 399 struct device *dev = uap->port.dev; 400 struct dma_slave_config tx_conf = { 401 .dst_addr = uap->port.mapbase + 402 pl011_reg_to_offset(uap, REG_DR), 403 .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, 404 .direction = DMA_MEM_TO_DEV, 405 .dst_maxburst = uap->fifosize >> 1, 406 .device_fc = false, 407 }; 408 struct dma_chan *chan; 409 dma_cap_mask_t mask; 410 411 uap->dma_probed = true; 412 chan = dma_request_chan(dev, "tx"); 413 if (IS_ERR(chan)) { 414 if (PTR_ERR(chan) == -EPROBE_DEFER) { 415 uap->dma_probed = false; 416 return; 417 } 418 419 /* We need platform data */ 420 if (!plat || !plat->dma_filter) { 421 dev_info(uap->port.dev, "no DMA platform data\n"); 422 return; 423 } 424 425 /* Try to acquire a generic DMA engine slave TX channel */ 426 dma_cap_zero(mask); 427 dma_cap_set(DMA_SLAVE, mask); 428 429 chan = dma_request_channel(mask, plat->dma_filter, 430 plat->dma_tx_param); 431 if (!chan) { 432 dev_err(uap->port.dev, "no TX DMA channel!\n"); 433 return; 434 } 435 } 436 437 dmaengine_slave_config(chan, &tx_conf); 438 uap->dmatx.chan = chan; 439 440 dev_info(uap->port.dev, "DMA channel TX %s\n", 441 dma_chan_name(uap->dmatx.chan)); 442 443 /* Optionally make use of an RX channel as well */ 444 chan = dma_request_slave_channel(dev, "rx"); 445 446 if (!chan && plat && plat->dma_rx_param) { 447 chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param); 448 449 if (!chan) { 450 dev_err(uap->port.dev, "no RX DMA channel!\n"); 451 return; 452 } 453 } 454 455 if (chan) { 456 struct dma_slave_config rx_conf = { 457 .src_addr = uap->port.mapbase + 458 pl011_reg_to_offset(uap, REG_DR), 459 .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, 460 .direction = DMA_DEV_TO_MEM, 461 .src_maxburst = uap->fifosize >> 2, 462 .device_fc = false, 463 }; 464 struct dma_slave_caps caps; 465 466 /* 467 * Some DMA controllers provide information on their capabilities. 468 * If the controller does, check for suitable residue processing 469 * otherwise assime all is well. 470 */ 471 if (0 == dma_get_slave_caps(chan, &caps)) { 472 if (caps.residue_granularity == 473 DMA_RESIDUE_GRANULARITY_DESCRIPTOR) { 474 dma_release_channel(chan); 475 dev_info(uap->port.dev, 476 "RX DMA disabled - no residue processing\n"); 477 return; 478 } 479 } 480 dmaengine_slave_config(chan, &rx_conf); 481 uap->dmarx.chan = chan; 482 483 uap->dmarx.auto_poll_rate = false; 484 if (plat && plat->dma_rx_poll_enable) { 485 /* Set poll rate if specified. */ 486 if (plat->dma_rx_poll_rate) { 487 uap->dmarx.auto_poll_rate = false; 488 uap->dmarx.poll_rate = plat->dma_rx_poll_rate; 489 } else { 490 /* 491 * 100 ms defaults to poll rate if not 492 * specified. This will be adjusted with 493 * the baud rate at set_termios. 494 */ 495 uap->dmarx.auto_poll_rate = true; 496 uap->dmarx.poll_rate = 100; 497 } 498 /* 3 secs defaults poll_timeout if not specified. */ 499 if (plat->dma_rx_poll_timeout) 500 uap->dmarx.poll_timeout = 501 plat->dma_rx_poll_timeout; 502 else 503 uap->dmarx.poll_timeout = 3000; 504 } else if (!plat && dev->of_node) { 505 uap->dmarx.auto_poll_rate = of_property_read_bool( 506 dev->of_node, "auto-poll"); 507 if (uap->dmarx.auto_poll_rate) { 508 u32 x; 509 510 if (0 == of_property_read_u32(dev->of_node, 511 "poll-rate-ms", &x)) 512 uap->dmarx.poll_rate = x; 513 else 514 uap->dmarx.poll_rate = 100; 515 if (0 == of_property_read_u32(dev->of_node, 516 "poll-timeout-ms", &x)) 517 uap->dmarx.poll_timeout = x; 518 else 519 uap->dmarx.poll_timeout = 3000; 520 } 521 } 522 dev_info(uap->port.dev, "DMA channel RX %s\n", 523 dma_chan_name(uap->dmarx.chan)); 524 } 525 } 526 527 static void pl011_dma_remove(struct uart_amba_port *uap) 528 { 529 if (uap->dmatx.chan) 530 dma_release_channel(uap->dmatx.chan); 531 if (uap->dmarx.chan) 532 dma_release_channel(uap->dmarx.chan); 533 } 534 535 /* Forward declare these for the refill routine */ 536 static int pl011_dma_tx_refill(struct uart_amba_port *uap); 537 static void pl011_start_tx_pio(struct uart_amba_port *uap); 538 539 /* 540 * The current DMA TX buffer has been sent. 541 * Try to queue up another DMA buffer. 542 */ 543 static void pl011_dma_tx_callback(void *data) 544 { 545 struct uart_amba_port *uap = data; 546 struct pl011_dmatx_data *dmatx = &uap->dmatx; 547 unsigned long flags; 548 u16 dmacr; 549 550 spin_lock_irqsave(&uap->port.lock, flags); 551 if (uap->dmatx.queued) 552 dma_unmap_sg(dmatx->chan->device->dev, &dmatx->sg, 1, 553 DMA_TO_DEVICE); 554 555 dmacr = uap->dmacr; 556 uap->dmacr = dmacr & ~UART011_TXDMAE; 557 pl011_write(uap->dmacr, uap, REG_DMACR); 558 559 /* 560 * If TX DMA was disabled, it means that we've stopped the DMA for 561 * some reason (eg, XOFF received, or we want to send an X-char.) 562 * 563 * Note: we need to be careful here of a potential race between DMA 564 * and the rest of the driver - if the driver disables TX DMA while 565 * a TX buffer completing, we must update the tx queued status to 566 * get further refills (hence we check dmacr). 567 */ 568 if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) || 569 uart_circ_empty(&uap->port.state->xmit)) { 570 uap->dmatx.queued = false; 571 spin_unlock_irqrestore(&uap->port.lock, flags); 572 return; 573 } 574 575 if (pl011_dma_tx_refill(uap) <= 0) 576 /* 577 * We didn't queue a DMA buffer for some reason, but we 578 * have data pending to be sent. Re-enable the TX IRQ. 579 */ 580 pl011_start_tx_pio(uap); 581 582 spin_unlock_irqrestore(&uap->port.lock, flags); 583 } 584 585 /* 586 * Try to refill the TX DMA buffer. 587 * Locking: called with port lock held and IRQs disabled. 588 * Returns: 589 * 1 if we queued up a TX DMA buffer. 590 * 0 if we didn't want to handle this by DMA 591 * <0 on error 592 */ 593 static int pl011_dma_tx_refill(struct uart_amba_port *uap) 594 { 595 struct pl011_dmatx_data *dmatx = &uap->dmatx; 596 struct dma_chan *chan = dmatx->chan; 597 struct dma_device *dma_dev = chan->device; 598 struct dma_async_tx_descriptor *desc; 599 struct circ_buf *xmit = &uap->port.state->xmit; 600 unsigned int count; 601 602 /* 603 * Try to avoid the overhead involved in using DMA if the 604 * transaction fits in the first half of the FIFO, by using 605 * the standard interrupt handling. This ensures that we 606 * issue a uart_write_wakeup() at the appropriate time. 607 */ 608 count = uart_circ_chars_pending(xmit); 609 if (count < (uap->fifosize >> 1)) { 610 uap->dmatx.queued = false; 611 return 0; 612 } 613 614 /* 615 * Bodge: don't send the last character by DMA, as this 616 * will prevent XON from notifying us to restart DMA. 617 */ 618 count -= 1; 619 620 /* Else proceed to copy the TX chars to the DMA buffer and fire DMA */ 621 if (count > PL011_DMA_BUFFER_SIZE) 622 count = PL011_DMA_BUFFER_SIZE; 623 624 if (xmit->tail < xmit->head) 625 memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count); 626 else { 627 size_t first = UART_XMIT_SIZE - xmit->tail; 628 size_t second; 629 630 if (first > count) 631 first = count; 632 second = count - first; 633 634 memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first); 635 if (second) 636 memcpy(&dmatx->buf[first], &xmit->buf[0], second); 637 } 638 639 dmatx->sg.length = count; 640 641 if (dma_map_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE) != 1) { 642 uap->dmatx.queued = false; 643 dev_dbg(uap->port.dev, "unable to map TX DMA\n"); 644 return -EBUSY; 645 } 646 647 desc = dmaengine_prep_slave_sg(chan, &dmatx->sg, 1, DMA_MEM_TO_DEV, 648 DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 649 if (!desc) { 650 dma_unmap_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE); 651 uap->dmatx.queued = false; 652 /* 653 * If DMA cannot be used right now, we complete this 654 * transaction via IRQ and let the TTY layer retry. 655 */ 656 dev_dbg(uap->port.dev, "TX DMA busy\n"); 657 return -EBUSY; 658 } 659 660 /* Some data to go along to the callback */ 661 desc->callback = pl011_dma_tx_callback; 662 desc->callback_param = uap; 663 664 /* All errors should happen at prepare time */ 665 dmaengine_submit(desc); 666 667 /* Fire the DMA transaction */ 668 dma_dev->device_issue_pending(chan); 669 670 uap->dmacr |= UART011_TXDMAE; 671 pl011_write(uap->dmacr, uap, REG_DMACR); 672 uap->dmatx.queued = true; 673 674 /* 675 * Now we know that DMA will fire, so advance the ring buffer 676 * with the stuff we just dispatched. 677 */ 678 xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1); 679 uap->port.icount.tx += count; 680 681 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 682 uart_write_wakeup(&uap->port); 683 684 return 1; 685 } 686 687 /* 688 * We received a transmit interrupt without a pending X-char but with 689 * pending characters. 690 * Locking: called with port lock held and IRQs disabled. 691 * Returns: 692 * false if we want to use PIO to transmit 693 * true if we queued a DMA buffer 694 */ 695 static bool pl011_dma_tx_irq(struct uart_amba_port *uap) 696 { 697 if (!uap->using_tx_dma) 698 return false; 699 700 /* 701 * If we already have a TX buffer queued, but received a 702 * TX interrupt, it will be because we've just sent an X-char. 703 * Ensure the TX DMA is enabled and the TX IRQ is disabled. 704 */ 705 if (uap->dmatx.queued) { 706 uap->dmacr |= UART011_TXDMAE; 707 pl011_write(uap->dmacr, uap, REG_DMACR); 708 uap->im &= ~UART011_TXIM; 709 pl011_write(uap->im, uap, REG_IMSC); 710 return true; 711 } 712 713 /* 714 * We don't have a TX buffer queued, so try to queue one. 715 * If we successfully queued a buffer, mask the TX IRQ. 716 */ 717 if (pl011_dma_tx_refill(uap) > 0) { 718 uap->im &= ~UART011_TXIM; 719 pl011_write(uap->im, uap, REG_IMSC); 720 return true; 721 } 722 return false; 723 } 724 725 /* 726 * Stop the DMA transmit (eg, due to received XOFF). 727 * Locking: called with port lock held and IRQs disabled. 728 */ 729 static inline void pl011_dma_tx_stop(struct uart_amba_port *uap) 730 { 731 if (uap->dmatx.queued) { 732 uap->dmacr &= ~UART011_TXDMAE; 733 pl011_write(uap->dmacr, uap, REG_DMACR); 734 } 735 } 736 737 /* 738 * Try to start a DMA transmit, or in the case of an XON/OFF 739 * character queued for send, try to get that character out ASAP. 740 * Locking: called with port lock held and IRQs disabled. 741 * Returns: 742 * false if we want the TX IRQ to be enabled 743 * true if we have a buffer queued 744 */ 745 static inline bool pl011_dma_tx_start(struct uart_amba_port *uap) 746 { 747 u16 dmacr; 748 749 if (!uap->using_tx_dma) 750 return false; 751 752 if (!uap->port.x_char) { 753 /* no X-char, try to push chars out in DMA mode */ 754 bool ret = true; 755 756 if (!uap->dmatx.queued) { 757 if (pl011_dma_tx_refill(uap) > 0) { 758 uap->im &= ~UART011_TXIM; 759 pl011_write(uap->im, uap, REG_IMSC); 760 } else 761 ret = false; 762 } else if (!(uap->dmacr & UART011_TXDMAE)) { 763 uap->dmacr |= UART011_TXDMAE; 764 pl011_write(uap->dmacr, uap, REG_DMACR); 765 } 766 return ret; 767 } 768 769 /* 770 * We have an X-char to send. Disable DMA to prevent it loading 771 * the TX fifo, and then see if we can stuff it into the FIFO. 772 */ 773 dmacr = uap->dmacr; 774 uap->dmacr &= ~UART011_TXDMAE; 775 pl011_write(uap->dmacr, uap, REG_DMACR); 776 777 if (pl011_read(uap, REG_FR) & UART01x_FR_TXFF) { 778 /* 779 * No space in the FIFO, so enable the transmit interrupt 780 * so we know when there is space. Note that once we've 781 * loaded the character, we should just re-enable DMA. 782 */ 783 return false; 784 } 785 786 pl011_write(uap->port.x_char, uap, REG_DR); 787 uap->port.icount.tx++; 788 uap->port.x_char = 0; 789 790 /* Success - restore the DMA state */ 791 uap->dmacr = dmacr; 792 pl011_write(dmacr, uap, REG_DMACR); 793 794 return true; 795 } 796 797 /* 798 * Flush the transmit buffer. 799 * Locking: called with port lock held and IRQs disabled. 800 */ 801 static void pl011_dma_flush_buffer(struct uart_port *port) 802 __releases(&uap->port.lock) 803 __acquires(&uap->port.lock) 804 { 805 struct uart_amba_port *uap = 806 container_of(port, struct uart_amba_port, port); 807 808 if (!uap->using_tx_dma) 809 return; 810 811 dmaengine_terminate_async(uap->dmatx.chan); 812 813 if (uap->dmatx.queued) { 814 dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1, 815 DMA_TO_DEVICE); 816 uap->dmatx.queued = false; 817 uap->dmacr &= ~UART011_TXDMAE; 818 pl011_write(uap->dmacr, uap, REG_DMACR); 819 } 820 } 821 822 static void pl011_dma_rx_callback(void *data); 823 824 static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap) 825 { 826 struct dma_chan *rxchan = uap->dmarx.chan; 827 struct pl011_dmarx_data *dmarx = &uap->dmarx; 828 struct dma_async_tx_descriptor *desc; 829 struct pl011_sgbuf *sgbuf; 830 831 if (!rxchan) 832 return -EIO; 833 834 /* Start the RX DMA job */ 835 sgbuf = uap->dmarx.use_buf_b ? 836 &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; 837 desc = dmaengine_prep_slave_sg(rxchan, &sgbuf->sg, 1, 838 DMA_DEV_TO_MEM, 839 DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 840 /* 841 * If the DMA engine is busy and cannot prepare a 842 * channel, no big deal, the driver will fall back 843 * to interrupt mode as a result of this error code. 844 */ 845 if (!desc) { 846 uap->dmarx.running = false; 847 dmaengine_terminate_all(rxchan); 848 return -EBUSY; 849 } 850 851 /* Some data to go along to the callback */ 852 desc->callback = pl011_dma_rx_callback; 853 desc->callback_param = uap; 854 dmarx->cookie = dmaengine_submit(desc); 855 dma_async_issue_pending(rxchan); 856 857 uap->dmacr |= UART011_RXDMAE; 858 pl011_write(uap->dmacr, uap, REG_DMACR); 859 uap->dmarx.running = true; 860 861 uap->im &= ~UART011_RXIM; 862 pl011_write(uap->im, uap, REG_IMSC); 863 864 return 0; 865 } 866 867 /* 868 * This is called when either the DMA job is complete, or 869 * the FIFO timeout interrupt occurred. This must be called 870 * with the port spinlock uap->port.lock held. 871 */ 872 static void pl011_dma_rx_chars(struct uart_amba_port *uap, 873 u32 pending, bool use_buf_b, 874 bool readfifo) 875 { 876 struct tty_port *port = &uap->port.state->port; 877 struct pl011_sgbuf *sgbuf = use_buf_b ? 878 &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; 879 int dma_count = 0; 880 u32 fifotaken = 0; /* only used for vdbg() */ 881 882 struct pl011_dmarx_data *dmarx = &uap->dmarx; 883 int dmataken = 0; 884 885 if (uap->dmarx.poll_rate) { 886 /* The data can be taken by polling */ 887 dmataken = sgbuf->sg.length - dmarx->last_residue; 888 /* Recalculate the pending size */ 889 if (pending >= dmataken) 890 pending -= dmataken; 891 } 892 893 /* Pick the remain data from the DMA */ 894 if (pending) { 895 896 /* 897 * First take all chars in the DMA pipe, then look in the FIFO. 898 * Note that tty_insert_flip_buf() tries to take as many chars 899 * as it can. 900 */ 901 dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken, 902 pending); 903 904 uap->port.icount.rx += dma_count; 905 if (dma_count < pending) 906 dev_warn(uap->port.dev, 907 "couldn't insert all characters (TTY is full?)\n"); 908 } 909 910 /* Reset the last_residue for Rx DMA poll */ 911 if (uap->dmarx.poll_rate) 912 dmarx->last_residue = sgbuf->sg.length; 913 914 /* 915 * Only continue with trying to read the FIFO if all DMA chars have 916 * been taken first. 917 */ 918 if (dma_count == pending && readfifo) { 919 /* Clear any error flags */ 920 pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS | 921 UART011_FEIS, uap, REG_ICR); 922 923 /* 924 * If we read all the DMA'd characters, and we had an 925 * incomplete buffer, that could be due to an rx error, or 926 * maybe we just timed out. Read any pending chars and check 927 * the error status. 928 * 929 * Error conditions will only occur in the FIFO, these will 930 * trigger an immediate interrupt and stop the DMA job, so we 931 * will always find the error in the FIFO, never in the DMA 932 * buffer. 933 */ 934 fifotaken = pl011_fifo_to_tty(uap); 935 } 936 937 spin_unlock(&uap->port.lock); 938 dev_vdbg(uap->port.dev, 939 "Took %d chars from DMA buffer and %d chars from the FIFO\n", 940 dma_count, fifotaken); 941 tty_flip_buffer_push(port); 942 spin_lock(&uap->port.lock); 943 } 944 945 static void pl011_dma_rx_irq(struct uart_amba_port *uap) 946 { 947 struct pl011_dmarx_data *dmarx = &uap->dmarx; 948 struct dma_chan *rxchan = dmarx->chan; 949 struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ? 950 &dmarx->sgbuf_b : &dmarx->sgbuf_a; 951 size_t pending; 952 struct dma_tx_state state; 953 enum dma_status dmastat; 954 955 /* 956 * Pause the transfer so we can trust the current counter, 957 * do this before we pause the PL011 block, else we may 958 * overflow the FIFO. 959 */ 960 if (dmaengine_pause(rxchan)) 961 dev_err(uap->port.dev, "unable to pause DMA transfer\n"); 962 dmastat = rxchan->device->device_tx_status(rxchan, 963 dmarx->cookie, &state); 964 if (dmastat != DMA_PAUSED) 965 dev_err(uap->port.dev, "unable to pause DMA transfer\n"); 966 967 /* Disable RX DMA - incoming data will wait in the FIFO */ 968 uap->dmacr &= ~UART011_RXDMAE; 969 pl011_write(uap->dmacr, uap, REG_DMACR); 970 uap->dmarx.running = false; 971 972 pending = sgbuf->sg.length - state.residue; 973 BUG_ON(pending > PL011_DMA_BUFFER_SIZE); 974 /* Then we terminate the transfer - we now know our residue */ 975 dmaengine_terminate_all(rxchan); 976 977 /* 978 * This will take the chars we have so far and insert 979 * into the framework. 980 */ 981 pl011_dma_rx_chars(uap, pending, dmarx->use_buf_b, true); 982 983 /* Switch buffer & re-trigger DMA job */ 984 dmarx->use_buf_b = !dmarx->use_buf_b; 985 if (pl011_dma_rx_trigger_dma(uap)) { 986 dev_dbg(uap->port.dev, "could not retrigger RX DMA job " 987 "fall back to interrupt mode\n"); 988 uap->im |= UART011_RXIM; 989 pl011_write(uap->im, uap, REG_IMSC); 990 } 991 } 992 993 static void pl011_dma_rx_callback(void *data) 994 { 995 struct uart_amba_port *uap = data; 996 struct pl011_dmarx_data *dmarx = &uap->dmarx; 997 struct dma_chan *rxchan = dmarx->chan; 998 bool lastbuf = dmarx->use_buf_b; 999 struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ? 1000 &dmarx->sgbuf_b : &dmarx->sgbuf_a; 1001 size_t pending; 1002 struct dma_tx_state state; 1003 int ret; 1004 1005 /* 1006 * This completion interrupt occurs typically when the 1007 * RX buffer is totally stuffed but no timeout has yet 1008 * occurred. When that happens, we just want the RX 1009 * routine to flush out the secondary DMA buffer while 1010 * we immediately trigger the next DMA job. 1011 */ 1012 spin_lock_irq(&uap->port.lock); 1013 /* 1014 * Rx data can be taken by the UART interrupts during 1015 * the DMA irq handler. So we check the residue here. 1016 */ 1017 rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state); 1018 pending = sgbuf->sg.length - state.residue; 1019 BUG_ON(pending > PL011_DMA_BUFFER_SIZE); 1020 /* Then we terminate the transfer - we now know our residue */ 1021 dmaengine_terminate_all(rxchan); 1022 1023 uap->dmarx.running = false; 1024 dmarx->use_buf_b = !lastbuf; 1025 ret = pl011_dma_rx_trigger_dma(uap); 1026 1027 pl011_dma_rx_chars(uap, pending, lastbuf, false); 1028 spin_unlock_irq(&uap->port.lock); 1029 /* 1030 * Do this check after we picked the DMA chars so we don't 1031 * get some IRQ immediately from RX. 1032 */ 1033 if (ret) { 1034 dev_dbg(uap->port.dev, "could not retrigger RX DMA job " 1035 "fall back to interrupt mode\n"); 1036 uap->im |= UART011_RXIM; 1037 pl011_write(uap->im, uap, REG_IMSC); 1038 } 1039 } 1040 1041 /* 1042 * Stop accepting received characters, when we're shutting down or 1043 * suspending this port. 1044 * Locking: called with port lock held and IRQs disabled. 1045 */ 1046 static inline void pl011_dma_rx_stop(struct uart_amba_port *uap) 1047 { 1048 /* FIXME. Just disable the DMA enable */ 1049 uap->dmacr &= ~UART011_RXDMAE; 1050 pl011_write(uap->dmacr, uap, REG_DMACR); 1051 } 1052 1053 /* 1054 * Timer handler for Rx DMA polling. 1055 * Every polling, It checks the residue in the dma buffer and transfer 1056 * data to the tty. Also, last_residue is updated for the next polling. 1057 */ 1058 static void pl011_dma_rx_poll(struct timer_list *t) 1059 { 1060 struct uart_amba_port *uap = from_timer(uap, t, dmarx.timer); 1061 struct tty_port *port = &uap->port.state->port; 1062 struct pl011_dmarx_data *dmarx = &uap->dmarx; 1063 struct dma_chan *rxchan = uap->dmarx.chan; 1064 unsigned long flags = 0; 1065 unsigned int dmataken = 0; 1066 unsigned int size = 0; 1067 struct pl011_sgbuf *sgbuf; 1068 int dma_count; 1069 struct dma_tx_state state; 1070 1071 sgbuf = dmarx->use_buf_b ? &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; 1072 rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state); 1073 if (likely(state.residue < dmarx->last_residue)) { 1074 dmataken = sgbuf->sg.length - dmarx->last_residue; 1075 size = dmarx->last_residue - state.residue; 1076 dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken, 1077 size); 1078 if (dma_count == size) 1079 dmarx->last_residue = state.residue; 1080 dmarx->last_jiffies = jiffies; 1081 } 1082 tty_flip_buffer_push(port); 1083 1084 /* 1085 * If no data is received in poll_timeout, the driver will fall back 1086 * to interrupt mode. We will retrigger DMA at the first interrupt. 1087 */ 1088 if (jiffies_to_msecs(jiffies - dmarx->last_jiffies) 1089 > uap->dmarx.poll_timeout) { 1090 1091 spin_lock_irqsave(&uap->port.lock, flags); 1092 pl011_dma_rx_stop(uap); 1093 uap->im |= UART011_RXIM; 1094 pl011_write(uap->im, uap, REG_IMSC); 1095 spin_unlock_irqrestore(&uap->port.lock, flags); 1096 1097 uap->dmarx.running = false; 1098 dmaengine_terminate_all(rxchan); 1099 del_timer(&uap->dmarx.timer); 1100 } else { 1101 mod_timer(&uap->dmarx.timer, 1102 jiffies + msecs_to_jiffies(uap->dmarx.poll_rate)); 1103 } 1104 } 1105 1106 static void pl011_dma_startup(struct uart_amba_port *uap) 1107 { 1108 int ret; 1109 1110 if (!uap->dma_probed) 1111 pl011_dma_probe(uap); 1112 1113 if (!uap->dmatx.chan) 1114 return; 1115 1116 uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL | __GFP_DMA); 1117 if (!uap->dmatx.buf) { 1118 dev_err(uap->port.dev, "no memory for DMA TX buffer\n"); 1119 uap->port.fifosize = uap->fifosize; 1120 return; 1121 } 1122 1123 sg_init_one(&uap->dmatx.sg, uap->dmatx.buf, PL011_DMA_BUFFER_SIZE); 1124 1125 /* The DMA buffer is now the FIFO the TTY subsystem can use */ 1126 uap->port.fifosize = PL011_DMA_BUFFER_SIZE; 1127 uap->using_tx_dma = true; 1128 1129 if (!uap->dmarx.chan) 1130 goto skip_rx; 1131 1132 /* Allocate and map DMA RX buffers */ 1133 ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_a, 1134 DMA_FROM_DEVICE); 1135 if (ret) { 1136 dev_err(uap->port.dev, "failed to init DMA %s: %d\n", 1137 "RX buffer A", ret); 1138 goto skip_rx; 1139 } 1140 1141 ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_b, 1142 DMA_FROM_DEVICE); 1143 if (ret) { 1144 dev_err(uap->port.dev, "failed to init DMA %s: %d\n", 1145 "RX buffer B", ret); 1146 pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, 1147 DMA_FROM_DEVICE); 1148 goto skip_rx; 1149 } 1150 1151 uap->using_rx_dma = true; 1152 1153 skip_rx: 1154 /* Turn on DMA error (RX/TX will be enabled on demand) */ 1155 uap->dmacr |= UART011_DMAONERR; 1156 pl011_write(uap->dmacr, uap, REG_DMACR); 1157 1158 /* 1159 * ST Micro variants has some specific dma burst threshold 1160 * compensation. Set this to 16 bytes, so burst will only 1161 * be issued above/below 16 bytes. 1162 */ 1163 if (uap->vendor->dma_threshold) 1164 pl011_write(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16, 1165 uap, REG_ST_DMAWM); 1166 1167 if (uap->using_rx_dma) { 1168 if (pl011_dma_rx_trigger_dma(uap)) 1169 dev_dbg(uap->port.dev, "could not trigger initial " 1170 "RX DMA job, fall back to interrupt mode\n"); 1171 if (uap->dmarx.poll_rate) { 1172 timer_setup(&uap->dmarx.timer, pl011_dma_rx_poll, 0); 1173 mod_timer(&uap->dmarx.timer, 1174 jiffies + 1175 msecs_to_jiffies(uap->dmarx.poll_rate)); 1176 uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE; 1177 uap->dmarx.last_jiffies = jiffies; 1178 } 1179 } 1180 } 1181 1182 static void pl011_dma_shutdown(struct uart_amba_port *uap) 1183 { 1184 if (!(uap->using_tx_dma || uap->using_rx_dma)) 1185 return; 1186 1187 /* Disable RX and TX DMA */ 1188 while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy) 1189 cpu_relax(); 1190 1191 spin_lock_irq(&uap->port.lock); 1192 uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE); 1193 pl011_write(uap->dmacr, uap, REG_DMACR); 1194 spin_unlock_irq(&uap->port.lock); 1195 1196 if (uap->using_tx_dma) { 1197 /* In theory, this should already be done by pl011_dma_flush_buffer */ 1198 dmaengine_terminate_all(uap->dmatx.chan); 1199 if (uap->dmatx.queued) { 1200 dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1, 1201 DMA_TO_DEVICE); 1202 uap->dmatx.queued = false; 1203 } 1204 1205 kfree(uap->dmatx.buf); 1206 uap->using_tx_dma = false; 1207 } 1208 1209 if (uap->using_rx_dma) { 1210 dmaengine_terminate_all(uap->dmarx.chan); 1211 /* Clean up the RX DMA */ 1212 pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, DMA_FROM_DEVICE); 1213 pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_b, DMA_FROM_DEVICE); 1214 if (uap->dmarx.poll_rate) 1215 del_timer_sync(&uap->dmarx.timer); 1216 uap->using_rx_dma = false; 1217 } 1218 } 1219 1220 static inline bool pl011_dma_rx_available(struct uart_amba_port *uap) 1221 { 1222 return uap->using_rx_dma; 1223 } 1224 1225 static inline bool pl011_dma_rx_running(struct uart_amba_port *uap) 1226 { 1227 return uap->using_rx_dma && uap->dmarx.running; 1228 } 1229 1230 #else 1231 /* Blank functions if the DMA engine is not available */ 1232 static inline void pl011_dma_remove(struct uart_amba_port *uap) 1233 { 1234 } 1235 1236 static inline void pl011_dma_startup(struct uart_amba_port *uap) 1237 { 1238 } 1239 1240 static inline void pl011_dma_shutdown(struct uart_amba_port *uap) 1241 { 1242 } 1243 1244 static inline bool pl011_dma_tx_irq(struct uart_amba_port *uap) 1245 { 1246 return false; 1247 } 1248 1249 static inline void pl011_dma_tx_stop(struct uart_amba_port *uap) 1250 { 1251 } 1252 1253 static inline bool pl011_dma_tx_start(struct uart_amba_port *uap) 1254 { 1255 return false; 1256 } 1257 1258 static inline void pl011_dma_rx_irq(struct uart_amba_port *uap) 1259 { 1260 } 1261 1262 static inline void pl011_dma_rx_stop(struct uart_amba_port *uap) 1263 { 1264 } 1265 1266 static inline int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap) 1267 { 1268 return -EIO; 1269 } 1270 1271 static inline bool pl011_dma_rx_available(struct uart_amba_port *uap) 1272 { 1273 return false; 1274 } 1275 1276 static inline bool pl011_dma_rx_running(struct uart_amba_port *uap) 1277 { 1278 return false; 1279 } 1280 1281 #define pl011_dma_flush_buffer NULL 1282 #endif 1283 1284 static void pl011_stop_tx(struct uart_port *port) 1285 { 1286 struct uart_amba_port *uap = 1287 container_of(port, struct uart_amba_port, port); 1288 1289 uap->im &= ~UART011_TXIM; 1290 pl011_write(uap->im, uap, REG_IMSC); 1291 pl011_dma_tx_stop(uap); 1292 } 1293 1294 static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq); 1295 1296 /* Start TX with programmed I/O only (no DMA) */ 1297 static void pl011_start_tx_pio(struct uart_amba_port *uap) 1298 { 1299 if (pl011_tx_chars(uap, false)) { 1300 uap->im |= UART011_TXIM; 1301 pl011_write(uap->im, uap, REG_IMSC); 1302 } 1303 } 1304 1305 static void pl011_start_tx(struct uart_port *port) 1306 { 1307 struct uart_amba_port *uap = 1308 container_of(port, struct uart_amba_port, port); 1309 1310 if (!pl011_dma_tx_start(uap)) 1311 pl011_start_tx_pio(uap); 1312 } 1313 1314 static void pl011_stop_rx(struct uart_port *port) 1315 { 1316 struct uart_amba_port *uap = 1317 container_of(port, struct uart_amba_port, port); 1318 1319 uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM| 1320 UART011_PEIM|UART011_BEIM|UART011_OEIM); 1321 pl011_write(uap->im, uap, REG_IMSC); 1322 1323 pl011_dma_rx_stop(uap); 1324 } 1325 1326 static void pl011_enable_ms(struct uart_port *port) 1327 { 1328 struct uart_amba_port *uap = 1329 container_of(port, struct uart_amba_port, port); 1330 1331 uap->im |= UART011_RIMIM|UART011_CTSMIM|UART011_DCDMIM|UART011_DSRMIM; 1332 pl011_write(uap->im, uap, REG_IMSC); 1333 } 1334 1335 static void pl011_rx_chars(struct uart_amba_port *uap) 1336 __releases(&uap->port.lock) 1337 __acquires(&uap->port.lock) 1338 { 1339 pl011_fifo_to_tty(uap); 1340 1341 spin_unlock(&uap->port.lock); 1342 tty_flip_buffer_push(&uap->port.state->port); 1343 /* 1344 * If we were temporarily out of DMA mode for a while, 1345 * attempt to switch back to DMA mode again. 1346 */ 1347 if (pl011_dma_rx_available(uap)) { 1348 if (pl011_dma_rx_trigger_dma(uap)) { 1349 dev_dbg(uap->port.dev, "could not trigger RX DMA job " 1350 "fall back to interrupt mode again\n"); 1351 uap->im |= UART011_RXIM; 1352 pl011_write(uap->im, uap, REG_IMSC); 1353 } else { 1354 #ifdef CONFIG_DMA_ENGINE 1355 /* Start Rx DMA poll */ 1356 if (uap->dmarx.poll_rate) { 1357 uap->dmarx.last_jiffies = jiffies; 1358 uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE; 1359 mod_timer(&uap->dmarx.timer, 1360 jiffies + 1361 msecs_to_jiffies(uap->dmarx.poll_rate)); 1362 } 1363 #endif 1364 } 1365 } 1366 spin_lock(&uap->port.lock); 1367 } 1368 1369 static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c, 1370 bool from_irq) 1371 { 1372 if (unlikely(!from_irq) && 1373 pl011_read(uap, REG_FR) & UART01x_FR_TXFF) 1374 return false; /* unable to transmit character */ 1375 1376 pl011_write(c, uap, REG_DR); 1377 uap->port.icount.tx++; 1378 1379 return true; 1380 } 1381 1382 /* Returns true if tx interrupts have to be (kept) enabled */ 1383 static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq) 1384 { 1385 struct circ_buf *xmit = &uap->port.state->xmit; 1386 int count = uap->fifosize >> 1; 1387 1388 if (uap->port.x_char) { 1389 if (!pl011_tx_char(uap, uap->port.x_char, from_irq)) 1390 return true; 1391 uap->port.x_char = 0; 1392 --count; 1393 } 1394 if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) { 1395 pl011_stop_tx(&uap->port); 1396 return false; 1397 } 1398 1399 /* If we are using DMA mode, try to send some characters. */ 1400 if (pl011_dma_tx_irq(uap)) 1401 return true; 1402 1403 do { 1404 if (likely(from_irq) && count-- == 0) 1405 break; 1406 1407 if (!pl011_tx_char(uap, xmit->buf[xmit->tail], from_irq)) 1408 break; 1409 1410 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); 1411 } while (!uart_circ_empty(xmit)); 1412 1413 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 1414 uart_write_wakeup(&uap->port); 1415 1416 if (uart_circ_empty(xmit)) { 1417 pl011_stop_tx(&uap->port); 1418 return false; 1419 } 1420 return true; 1421 } 1422 1423 static void pl011_modem_status(struct uart_amba_port *uap) 1424 { 1425 unsigned int status, delta; 1426 1427 status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY; 1428 1429 delta = status ^ uap->old_status; 1430 uap->old_status = status; 1431 1432 if (!delta) 1433 return; 1434 1435 if (delta & UART01x_FR_DCD) 1436 uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD); 1437 1438 if (delta & uap->vendor->fr_dsr) 1439 uap->port.icount.dsr++; 1440 1441 if (delta & uap->vendor->fr_cts) 1442 uart_handle_cts_change(&uap->port, 1443 status & uap->vendor->fr_cts); 1444 1445 wake_up_interruptible(&uap->port.state->port.delta_msr_wait); 1446 } 1447 1448 static void check_apply_cts_event_workaround(struct uart_amba_port *uap) 1449 { 1450 if (!uap->vendor->cts_event_workaround) 1451 return; 1452 1453 /* workaround to make sure that all bits are unlocked.. */ 1454 pl011_write(0x00, uap, REG_ICR); 1455 1456 /* 1457 * WA: introduce 26ns(1 uart clk) delay before W1C; 1458 * single apb access will incur 2 pclk(133.12Mhz) delay, 1459 * so add 2 dummy reads 1460 */ 1461 pl011_read(uap, REG_ICR); 1462 pl011_read(uap, REG_ICR); 1463 } 1464 1465 static irqreturn_t pl011_int(int irq, void *dev_id) 1466 { 1467 struct uart_amba_port *uap = dev_id; 1468 unsigned long flags; 1469 unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT; 1470 int handled = 0; 1471 1472 spin_lock_irqsave(&uap->port.lock, flags); 1473 status = pl011_read(uap, REG_RIS) & uap->im; 1474 if (status) { 1475 do { 1476 check_apply_cts_event_workaround(uap); 1477 1478 pl011_write(status & ~(UART011_TXIS|UART011_RTIS| 1479 UART011_RXIS), 1480 uap, REG_ICR); 1481 1482 if (status & (UART011_RTIS|UART011_RXIS)) { 1483 if (pl011_dma_rx_running(uap)) 1484 pl011_dma_rx_irq(uap); 1485 else 1486 pl011_rx_chars(uap); 1487 } 1488 if (status & (UART011_DSRMIS|UART011_DCDMIS| 1489 UART011_CTSMIS|UART011_RIMIS)) 1490 pl011_modem_status(uap); 1491 if (status & UART011_TXIS) 1492 pl011_tx_chars(uap, true); 1493 1494 if (pass_counter-- == 0) 1495 break; 1496 1497 status = pl011_read(uap, REG_RIS) & uap->im; 1498 } while (status != 0); 1499 handled = 1; 1500 } 1501 1502 spin_unlock_irqrestore(&uap->port.lock, flags); 1503 1504 return IRQ_RETVAL(handled); 1505 } 1506 1507 static unsigned int pl011_tx_empty(struct uart_port *port) 1508 { 1509 struct uart_amba_port *uap = 1510 container_of(port, struct uart_amba_port, port); 1511 1512 /* Allow feature register bits to be inverted to work around errata */ 1513 unsigned int status = pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr; 1514 1515 return status & (uap->vendor->fr_busy | UART01x_FR_TXFF) ? 1516 0 : TIOCSER_TEMT; 1517 } 1518 1519 static unsigned int pl011_get_mctrl(struct uart_port *port) 1520 { 1521 struct uart_amba_port *uap = 1522 container_of(port, struct uart_amba_port, port); 1523 unsigned int result = 0; 1524 unsigned int status = pl011_read(uap, REG_FR); 1525 1526 #define TIOCMBIT(uartbit, tiocmbit) \ 1527 if (status & uartbit) \ 1528 result |= tiocmbit 1529 1530 TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR); 1531 TIOCMBIT(uap->vendor->fr_dsr, TIOCM_DSR); 1532 TIOCMBIT(uap->vendor->fr_cts, TIOCM_CTS); 1533 TIOCMBIT(uap->vendor->fr_ri, TIOCM_RNG); 1534 #undef TIOCMBIT 1535 return result; 1536 } 1537 1538 static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl) 1539 { 1540 struct uart_amba_port *uap = 1541 container_of(port, struct uart_amba_port, port); 1542 unsigned int cr; 1543 1544 cr = pl011_read(uap, REG_CR); 1545 1546 #define TIOCMBIT(tiocmbit, uartbit) \ 1547 if (mctrl & tiocmbit) \ 1548 cr |= uartbit; \ 1549 else \ 1550 cr &= ~uartbit 1551 1552 TIOCMBIT(TIOCM_RTS, UART011_CR_RTS); 1553 TIOCMBIT(TIOCM_DTR, UART011_CR_DTR); 1554 TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1); 1555 TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2); 1556 TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE); 1557 1558 if (port->status & UPSTAT_AUTORTS) { 1559 /* We need to disable auto-RTS if we want to turn RTS off */ 1560 TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN); 1561 } 1562 #undef TIOCMBIT 1563 1564 pl011_write(cr, uap, REG_CR); 1565 } 1566 1567 static void pl011_break_ctl(struct uart_port *port, int break_state) 1568 { 1569 struct uart_amba_port *uap = 1570 container_of(port, struct uart_amba_port, port); 1571 unsigned long flags; 1572 unsigned int lcr_h; 1573 1574 spin_lock_irqsave(&uap->port.lock, flags); 1575 lcr_h = pl011_read(uap, REG_LCRH_TX); 1576 if (break_state == -1) 1577 lcr_h |= UART01x_LCRH_BRK; 1578 else 1579 lcr_h &= ~UART01x_LCRH_BRK; 1580 pl011_write(lcr_h, uap, REG_LCRH_TX); 1581 spin_unlock_irqrestore(&uap->port.lock, flags); 1582 } 1583 1584 #ifdef CONFIG_CONSOLE_POLL 1585 1586 static void pl011_quiesce_irqs(struct uart_port *port) 1587 { 1588 struct uart_amba_port *uap = 1589 container_of(port, struct uart_amba_port, port); 1590 1591 pl011_write(pl011_read(uap, REG_MIS), uap, REG_ICR); 1592 /* 1593 * There is no way to clear TXIM as this is "ready to transmit IRQ", so 1594 * we simply mask it. start_tx() will unmask it. 1595 * 1596 * Note we can race with start_tx(), and if the race happens, the 1597 * polling user might get another interrupt just after we clear it. 1598 * But it should be OK and can happen even w/o the race, e.g. 1599 * controller immediately got some new data and raised the IRQ. 1600 * 1601 * And whoever uses polling routines assumes that it manages the device 1602 * (including tx queue), so we're also fine with start_tx()'s caller 1603 * side. 1604 */ 1605 pl011_write(pl011_read(uap, REG_IMSC) & ~UART011_TXIM, uap, 1606 REG_IMSC); 1607 } 1608 1609 static int pl011_get_poll_char(struct uart_port *port) 1610 { 1611 struct uart_amba_port *uap = 1612 container_of(port, struct uart_amba_port, port); 1613 unsigned int status; 1614 1615 /* 1616 * The caller might need IRQs lowered, e.g. if used with KDB NMI 1617 * debugger. 1618 */ 1619 pl011_quiesce_irqs(port); 1620 1621 status = pl011_read(uap, REG_FR); 1622 if (status & UART01x_FR_RXFE) 1623 return NO_POLL_CHAR; 1624 1625 return pl011_read(uap, REG_DR); 1626 } 1627 1628 static void pl011_put_poll_char(struct uart_port *port, 1629 unsigned char ch) 1630 { 1631 struct uart_amba_port *uap = 1632 container_of(port, struct uart_amba_port, port); 1633 1634 while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF) 1635 cpu_relax(); 1636 1637 pl011_write(ch, uap, REG_DR); 1638 } 1639 1640 #endif /* CONFIG_CONSOLE_POLL */ 1641 1642 static int pl011_hwinit(struct uart_port *port) 1643 { 1644 struct uart_amba_port *uap = 1645 container_of(port, struct uart_amba_port, port); 1646 int retval; 1647 1648 /* Optionaly enable pins to be muxed in and configured */ 1649 pinctrl_pm_select_default_state(port->dev); 1650 1651 /* 1652 * Try to enable the clock producer. 1653 */ 1654 retval = clk_prepare_enable(uap->clk); 1655 if (retval) 1656 return retval; 1657 1658 uap->port.uartclk = clk_get_rate(uap->clk); 1659 1660 /* Clear pending error and receive interrupts */ 1661 pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS | 1662 UART011_FEIS | UART011_RTIS | UART011_RXIS, 1663 uap, REG_ICR); 1664 1665 /* 1666 * Save interrupts enable mask, and enable RX interrupts in case if 1667 * the interrupt is used for NMI entry. 1668 */ 1669 uap->im = pl011_read(uap, REG_IMSC); 1670 pl011_write(UART011_RTIM | UART011_RXIM, uap, REG_IMSC); 1671 1672 if (dev_get_platdata(uap->port.dev)) { 1673 struct amba_pl011_data *plat; 1674 1675 plat = dev_get_platdata(uap->port.dev); 1676 if (plat->init) 1677 plat->init(); 1678 } 1679 return 0; 1680 } 1681 1682 static bool pl011_split_lcrh(const struct uart_amba_port *uap) 1683 { 1684 return pl011_reg_to_offset(uap, REG_LCRH_RX) != 1685 pl011_reg_to_offset(uap, REG_LCRH_TX); 1686 } 1687 1688 static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h) 1689 { 1690 pl011_write(lcr_h, uap, REG_LCRH_RX); 1691 if (pl011_split_lcrh(uap)) { 1692 int i; 1693 /* 1694 * Wait 10 PCLKs before writing LCRH_TX register, 1695 * to get this delay write read only register 10 times 1696 */ 1697 for (i = 0; i < 10; ++i) 1698 pl011_write(0xff, uap, REG_MIS); 1699 pl011_write(lcr_h, uap, REG_LCRH_TX); 1700 } 1701 } 1702 1703 static int pl011_allocate_irq(struct uart_amba_port *uap) 1704 { 1705 pl011_write(uap->im, uap, REG_IMSC); 1706 1707 return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap); 1708 } 1709 1710 /* 1711 * Enable interrupts, only timeouts when using DMA 1712 * if initial RX DMA job failed, start in interrupt mode 1713 * as well. 1714 */ 1715 static void pl011_enable_interrupts(struct uart_amba_port *uap) 1716 { 1717 unsigned int i; 1718 1719 spin_lock_irq(&uap->port.lock); 1720 1721 /* Clear out any spuriously appearing RX interrupts */ 1722 pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR); 1723 1724 /* 1725 * RXIS is asserted only when the RX FIFO transitions from below 1726 * to above the trigger threshold. If the RX FIFO is already 1727 * full to the threshold this can't happen and RXIS will now be 1728 * stuck off. Drain the RX FIFO explicitly to fix this: 1729 */ 1730 for (i = 0; i < uap->fifosize * 2; ++i) { 1731 if (pl011_read(uap, REG_FR) & UART01x_FR_RXFE) 1732 break; 1733 1734 pl011_read(uap, REG_DR); 1735 } 1736 1737 uap->im = UART011_RTIM; 1738 if (!pl011_dma_rx_running(uap)) 1739 uap->im |= UART011_RXIM; 1740 pl011_write(uap->im, uap, REG_IMSC); 1741 spin_unlock_irq(&uap->port.lock); 1742 } 1743 1744 static int pl011_startup(struct uart_port *port) 1745 { 1746 struct uart_amba_port *uap = 1747 container_of(port, struct uart_amba_port, port); 1748 unsigned int cr; 1749 int retval; 1750 1751 retval = pl011_hwinit(port); 1752 if (retval) 1753 goto clk_dis; 1754 1755 retval = pl011_allocate_irq(uap); 1756 if (retval) 1757 goto clk_dis; 1758 1759 pl011_write(uap->vendor->ifls, uap, REG_IFLS); 1760 1761 spin_lock_irq(&uap->port.lock); 1762 1763 /* restore RTS and DTR */ 1764 cr = uap->old_cr & (UART011_CR_RTS | UART011_CR_DTR); 1765 cr |= UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE; 1766 pl011_write(cr, uap, REG_CR); 1767 1768 spin_unlock_irq(&uap->port.lock); 1769 1770 /* 1771 * initialise the old status of the modem signals 1772 */ 1773 uap->old_status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY; 1774 1775 /* Startup DMA */ 1776 pl011_dma_startup(uap); 1777 1778 pl011_enable_interrupts(uap); 1779 1780 return 0; 1781 1782 clk_dis: 1783 clk_disable_unprepare(uap->clk); 1784 return retval; 1785 } 1786 1787 static int sbsa_uart_startup(struct uart_port *port) 1788 { 1789 struct uart_amba_port *uap = 1790 container_of(port, struct uart_amba_port, port); 1791 int retval; 1792 1793 retval = pl011_hwinit(port); 1794 if (retval) 1795 return retval; 1796 1797 retval = pl011_allocate_irq(uap); 1798 if (retval) 1799 return retval; 1800 1801 /* The SBSA UART does not support any modem status lines. */ 1802 uap->old_status = 0; 1803 1804 pl011_enable_interrupts(uap); 1805 1806 return 0; 1807 } 1808 1809 static void pl011_shutdown_channel(struct uart_amba_port *uap, 1810 unsigned int lcrh) 1811 { 1812 unsigned long val; 1813 1814 val = pl011_read(uap, lcrh); 1815 val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN); 1816 pl011_write(val, uap, lcrh); 1817 } 1818 1819 /* 1820 * disable the port. It should not disable RTS and DTR. 1821 * Also RTS and DTR state should be preserved to restore 1822 * it during startup(). 1823 */ 1824 static void pl011_disable_uart(struct uart_amba_port *uap) 1825 { 1826 unsigned int cr; 1827 1828 uap->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS); 1829 spin_lock_irq(&uap->port.lock); 1830 cr = pl011_read(uap, REG_CR); 1831 uap->old_cr = cr; 1832 cr &= UART011_CR_RTS | UART011_CR_DTR; 1833 cr |= UART01x_CR_UARTEN | UART011_CR_TXE; 1834 pl011_write(cr, uap, REG_CR); 1835 spin_unlock_irq(&uap->port.lock); 1836 1837 /* 1838 * disable break condition and fifos 1839 */ 1840 pl011_shutdown_channel(uap, REG_LCRH_RX); 1841 if (pl011_split_lcrh(uap)) 1842 pl011_shutdown_channel(uap, REG_LCRH_TX); 1843 } 1844 1845 static void pl011_disable_interrupts(struct uart_amba_port *uap) 1846 { 1847 spin_lock_irq(&uap->port.lock); 1848 1849 /* mask all interrupts and clear all pending ones */ 1850 uap->im = 0; 1851 pl011_write(uap->im, uap, REG_IMSC); 1852 pl011_write(0xffff, uap, REG_ICR); 1853 1854 spin_unlock_irq(&uap->port.lock); 1855 } 1856 1857 static void pl011_shutdown(struct uart_port *port) 1858 { 1859 struct uart_amba_port *uap = 1860 container_of(port, struct uart_amba_port, port); 1861 1862 pl011_disable_interrupts(uap); 1863 1864 pl011_dma_shutdown(uap); 1865 1866 free_irq(uap->port.irq, uap); 1867 1868 pl011_disable_uart(uap); 1869 1870 /* 1871 * Shut down the clock producer 1872 */ 1873 clk_disable_unprepare(uap->clk); 1874 /* Optionally let pins go into sleep states */ 1875 pinctrl_pm_select_sleep_state(port->dev); 1876 1877 if (dev_get_platdata(uap->port.dev)) { 1878 struct amba_pl011_data *plat; 1879 1880 plat = dev_get_platdata(uap->port.dev); 1881 if (plat->exit) 1882 plat->exit(); 1883 } 1884 1885 if (uap->port.ops->flush_buffer) 1886 uap->port.ops->flush_buffer(port); 1887 } 1888 1889 static void sbsa_uart_shutdown(struct uart_port *port) 1890 { 1891 struct uart_amba_port *uap = 1892 container_of(port, struct uart_amba_port, port); 1893 1894 pl011_disable_interrupts(uap); 1895 1896 free_irq(uap->port.irq, uap); 1897 1898 if (uap->port.ops->flush_buffer) 1899 uap->port.ops->flush_buffer(port); 1900 } 1901 1902 static void 1903 pl011_setup_status_masks(struct uart_port *port, struct ktermios *termios) 1904 { 1905 port->read_status_mask = UART011_DR_OE | 255; 1906 if (termios->c_iflag & INPCK) 1907 port->read_status_mask |= UART011_DR_FE | UART011_DR_PE; 1908 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) 1909 port->read_status_mask |= UART011_DR_BE; 1910 1911 /* 1912 * Characters to ignore 1913 */ 1914 port->ignore_status_mask = 0; 1915 if (termios->c_iflag & IGNPAR) 1916 port->ignore_status_mask |= UART011_DR_FE | UART011_DR_PE; 1917 if (termios->c_iflag & IGNBRK) { 1918 port->ignore_status_mask |= UART011_DR_BE; 1919 /* 1920 * If we're ignoring parity and break indicators, 1921 * ignore overruns too (for real raw support). 1922 */ 1923 if (termios->c_iflag & IGNPAR) 1924 port->ignore_status_mask |= UART011_DR_OE; 1925 } 1926 1927 /* 1928 * Ignore all characters if CREAD is not set. 1929 */ 1930 if ((termios->c_cflag & CREAD) == 0) 1931 port->ignore_status_mask |= UART_DUMMY_DR_RX; 1932 } 1933 1934 static void 1935 pl011_set_termios(struct uart_port *port, struct ktermios *termios, 1936 struct ktermios *old) 1937 { 1938 struct uart_amba_port *uap = 1939 container_of(port, struct uart_amba_port, port); 1940 unsigned int lcr_h, old_cr; 1941 unsigned long flags; 1942 unsigned int baud, quot, clkdiv; 1943 1944 if (uap->vendor->oversampling) 1945 clkdiv = 8; 1946 else 1947 clkdiv = 16; 1948 1949 /* 1950 * Ask the core to calculate the divisor for us. 1951 */ 1952 baud = uart_get_baud_rate(port, termios, old, 0, 1953 port->uartclk / clkdiv); 1954 #ifdef CONFIG_DMA_ENGINE 1955 /* 1956 * Adjust RX DMA polling rate with baud rate if not specified. 1957 */ 1958 if (uap->dmarx.auto_poll_rate) 1959 uap->dmarx.poll_rate = DIV_ROUND_UP(10000000, baud); 1960 #endif 1961 1962 if (baud > port->uartclk/16) 1963 quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud); 1964 else 1965 quot = DIV_ROUND_CLOSEST(port->uartclk * 4, baud); 1966 1967 switch (termios->c_cflag & CSIZE) { 1968 case CS5: 1969 lcr_h = UART01x_LCRH_WLEN_5; 1970 break; 1971 case CS6: 1972 lcr_h = UART01x_LCRH_WLEN_6; 1973 break; 1974 case CS7: 1975 lcr_h = UART01x_LCRH_WLEN_7; 1976 break; 1977 default: // CS8 1978 lcr_h = UART01x_LCRH_WLEN_8; 1979 break; 1980 } 1981 if (termios->c_cflag & CSTOPB) 1982 lcr_h |= UART01x_LCRH_STP2; 1983 if (termios->c_cflag & PARENB) { 1984 lcr_h |= UART01x_LCRH_PEN; 1985 if (!(termios->c_cflag & PARODD)) 1986 lcr_h |= UART01x_LCRH_EPS; 1987 if (termios->c_cflag & CMSPAR) 1988 lcr_h |= UART011_LCRH_SPS; 1989 } 1990 if (uap->fifosize > 1) 1991 lcr_h |= UART01x_LCRH_FEN; 1992 1993 spin_lock_irqsave(&port->lock, flags); 1994 1995 /* 1996 * Update the per-port timeout. 1997 */ 1998 uart_update_timeout(port, termios->c_cflag, baud); 1999 2000 pl011_setup_status_masks(port, termios); 2001 2002 if (UART_ENABLE_MS(port, termios->c_cflag)) 2003 pl011_enable_ms(port); 2004 2005 /* first, disable everything */ 2006 old_cr = pl011_read(uap, REG_CR); 2007 pl011_write(0, uap, REG_CR); 2008 2009 if (termios->c_cflag & CRTSCTS) { 2010 if (old_cr & UART011_CR_RTS) 2011 old_cr |= UART011_CR_RTSEN; 2012 2013 old_cr |= UART011_CR_CTSEN; 2014 port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS; 2015 } else { 2016 old_cr &= ~(UART011_CR_CTSEN | UART011_CR_RTSEN); 2017 port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS); 2018 } 2019 2020 if (uap->vendor->oversampling) { 2021 if (baud > port->uartclk / 16) 2022 old_cr |= ST_UART011_CR_OVSFACT; 2023 else 2024 old_cr &= ~ST_UART011_CR_OVSFACT; 2025 } 2026 2027 /* 2028 * Workaround for the ST Micro oversampling variants to 2029 * increase the bitrate slightly, by lowering the divisor, 2030 * to avoid delayed sampling of start bit at high speeds, 2031 * else we see data corruption. 2032 */ 2033 if (uap->vendor->oversampling) { 2034 if ((baud >= 3000000) && (baud < 3250000) && (quot > 1)) 2035 quot -= 1; 2036 else if ((baud > 3250000) && (quot > 2)) 2037 quot -= 2; 2038 } 2039 /* Set baud rate */ 2040 pl011_write(quot & 0x3f, uap, REG_FBRD); 2041 pl011_write(quot >> 6, uap, REG_IBRD); 2042 2043 /* 2044 * ----------v----------v----------v----------v----- 2045 * NOTE: REG_LCRH_TX and REG_LCRH_RX MUST BE WRITTEN AFTER 2046 * REG_FBRD & REG_IBRD. 2047 * ----------^----------^----------^----------^----- 2048 */ 2049 pl011_write_lcr_h(uap, lcr_h); 2050 pl011_write(old_cr, uap, REG_CR); 2051 2052 spin_unlock_irqrestore(&port->lock, flags); 2053 } 2054 2055 static void 2056 sbsa_uart_set_termios(struct uart_port *port, struct ktermios *termios, 2057 struct ktermios *old) 2058 { 2059 struct uart_amba_port *uap = 2060 container_of(port, struct uart_amba_port, port); 2061 unsigned long flags; 2062 2063 tty_termios_encode_baud_rate(termios, uap->fixed_baud, uap->fixed_baud); 2064 2065 /* The SBSA UART only supports 8n1 without hardware flow control. */ 2066 termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD); 2067 termios->c_cflag &= ~(CMSPAR | CRTSCTS); 2068 termios->c_cflag |= CS8 | CLOCAL; 2069 2070 spin_lock_irqsave(&port->lock, flags); 2071 uart_update_timeout(port, CS8, uap->fixed_baud); 2072 pl011_setup_status_masks(port, termios); 2073 spin_unlock_irqrestore(&port->lock, flags); 2074 } 2075 2076 static const char *pl011_type(struct uart_port *port) 2077 { 2078 struct uart_amba_port *uap = 2079 container_of(port, struct uart_amba_port, port); 2080 return uap->port.type == PORT_AMBA ? uap->type : NULL; 2081 } 2082 2083 /* 2084 * Release the memory region(s) being used by 'port' 2085 */ 2086 static void pl011_release_port(struct uart_port *port) 2087 { 2088 release_mem_region(port->mapbase, SZ_4K); 2089 } 2090 2091 /* 2092 * Request the memory region(s) being used by 'port' 2093 */ 2094 static int pl011_request_port(struct uart_port *port) 2095 { 2096 return request_mem_region(port->mapbase, SZ_4K, "uart-pl011") 2097 != NULL ? 0 : -EBUSY; 2098 } 2099 2100 /* 2101 * Configure/autoconfigure the port. 2102 */ 2103 static void pl011_config_port(struct uart_port *port, int flags) 2104 { 2105 if (flags & UART_CONFIG_TYPE) { 2106 port->type = PORT_AMBA; 2107 pl011_request_port(port); 2108 } 2109 } 2110 2111 /* 2112 * verify the new serial_struct (for TIOCSSERIAL). 2113 */ 2114 static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser) 2115 { 2116 int ret = 0; 2117 if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA) 2118 ret = -EINVAL; 2119 if (ser->irq < 0 || ser->irq >= nr_irqs) 2120 ret = -EINVAL; 2121 if (ser->baud_base < 9600) 2122 ret = -EINVAL; 2123 return ret; 2124 } 2125 2126 static const struct uart_ops amba_pl011_pops = { 2127 .tx_empty = pl011_tx_empty, 2128 .set_mctrl = pl011_set_mctrl, 2129 .get_mctrl = pl011_get_mctrl, 2130 .stop_tx = pl011_stop_tx, 2131 .start_tx = pl011_start_tx, 2132 .stop_rx = pl011_stop_rx, 2133 .enable_ms = pl011_enable_ms, 2134 .break_ctl = pl011_break_ctl, 2135 .startup = pl011_startup, 2136 .shutdown = pl011_shutdown, 2137 .flush_buffer = pl011_dma_flush_buffer, 2138 .set_termios = pl011_set_termios, 2139 .type = pl011_type, 2140 .release_port = pl011_release_port, 2141 .request_port = pl011_request_port, 2142 .config_port = pl011_config_port, 2143 .verify_port = pl011_verify_port, 2144 #ifdef CONFIG_CONSOLE_POLL 2145 .poll_init = pl011_hwinit, 2146 .poll_get_char = pl011_get_poll_char, 2147 .poll_put_char = pl011_put_poll_char, 2148 #endif 2149 }; 2150 2151 static void sbsa_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) 2152 { 2153 } 2154 2155 static unsigned int sbsa_uart_get_mctrl(struct uart_port *port) 2156 { 2157 return 0; 2158 } 2159 2160 static const struct uart_ops sbsa_uart_pops = { 2161 .tx_empty = pl011_tx_empty, 2162 .set_mctrl = sbsa_uart_set_mctrl, 2163 .get_mctrl = sbsa_uart_get_mctrl, 2164 .stop_tx = pl011_stop_tx, 2165 .start_tx = pl011_start_tx, 2166 .stop_rx = pl011_stop_rx, 2167 .startup = sbsa_uart_startup, 2168 .shutdown = sbsa_uart_shutdown, 2169 .set_termios = sbsa_uart_set_termios, 2170 .type = pl011_type, 2171 .release_port = pl011_release_port, 2172 .request_port = pl011_request_port, 2173 .config_port = pl011_config_port, 2174 .verify_port = pl011_verify_port, 2175 #ifdef CONFIG_CONSOLE_POLL 2176 .poll_init = pl011_hwinit, 2177 .poll_get_char = pl011_get_poll_char, 2178 .poll_put_char = pl011_put_poll_char, 2179 #endif 2180 }; 2181 2182 static struct uart_amba_port *amba_ports[UART_NR]; 2183 2184 #ifdef CONFIG_SERIAL_AMBA_PL011_CONSOLE 2185 2186 static void pl011_console_putchar(struct uart_port *port, int ch) 2187 { 2188 struct uart_amba_port *uap = 2189 container_of(port, struct uart_amba_port, port); 2190 2191 while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF) 2192 cpu_relax(); 2193 pl011_write(ch, uap, REG_DR); 2194 } 2195 2196 static void 2197 pl011_console_write(struct console *co, const char *s, unsigned int count) 2198 { 2199 struct uart_amba_port *uap = amba_ports[co->index]; 2200 unsigned int old_cr = 0, new_cr; 2201 unsigned long flags; 2202 int locked = 1; 2203 2204 clk_enable(uap->clk); 2205 2206 local_irq_save(flags); 2207 if (uap->port.sysrq) 2208 locked = 0; 2209 else if (oops_in_progress) 2210 locked = spin_trylock(&uap->port.lock); 2211 else 2212 spin_lock(&uap->port.lock); 2213 2214 /* 2215 * First save the CR then disable the interrupts 2216 */ 2217 if (!uap->vendor->always_enabled) { 2218 old_cr = pl011_read(uap, REG_CR); 2219 new_cr = old_cr & ~UART011_CR_CTSEN; 2220 new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE; 2221 pl011_write(new_cr, uap, REG_CR); 2222 } 2223 2224 uart_console_write(&uap->port, s, count, pl011_console_putchar); 2225 2226 /* 2227 * Finally, wait for transmitter to become empty and restore the 2228 * TCR. Allow feature register bits to be inverted to work around 2229 * errata. 2230 */ 2231 while ((pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr) 2232 & uap->vendor->fr_busy) 2233 cpu_relax(); 2234 if (!uap->vendor->always_enabled) 2235 pl011_write(old_cr, uap, REG_CR); 2236 2237 if (locked) 2238 spin_unlock(&uap->port.lock); 2239 local_irq_restore(flags); 2240 2241 clk_disable(uap->clk); 2242 } 2243 2244 static void pl011_console_get_options(struct uart_amba_port *uap, int *baud, 2245 int *parity, int *bits) 2246 { 2247 if (pl011_read(uap, REG_CR) & UART01x_CR_UARTEN) { 2248 unsigned int lcr_h, ibrd, fbrd; 2249 2250 lcr_h = pl011_read(uap, REG_LCRH_TX); 2251 2252 *parity = 'n'; 2253 if (lcr_h & UART01x_LCRH_PEN) { 2254 if (lcr_h & UART01x_LCRH_EPS) 2255 *parity = 'e'; 2256 else 2257 *parity = 'o'; 2258 } 2259 2260 if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7) 2261 *bits = 7; 2262 else 2263 *bits = 8; 2264 2265 ibrd = pl011_read(uap, REG_IBRD); 2266 fbrd = pl011_read(uap, REG_FBRD); 2267 2268 *baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd); 2269 2270 if (uap->vendor->oversampling) { 2271 if (pl011_read(uap, REG_CR) 2272 & ST_UART011_CR_OVSFACT) 2273 *baud *= 2; 2274 } 2275 } 2276 } 2277 2278 static int pl011_console_setup(struct console *co, char *options) 2279 { 2280 struct uart_amba_port *uap; 2281 int baud = 38400; 2282 int bits = 8; 2283 int parity = 'n'; 2284 int flow = 'n'; 2285 int ret; 2286 2287 /* 2288 * Check whether an invalid uart number has been specified, and 2289 * if so, search for the first available port that does have 2290 * console support. 2291 */ 2292 if (co->index >= UART_NR) 2293 co->index = 0; 2294 uap = amba_ports[co->index]; 2295 if (!uap) 2296 return -ENODEV; 2297 2298 /* Allow pins to be muxed in and configured */ 2299 pinctrl_pm_select_default_state(uap->port.dev); 2300 2301 ret = clk_prepare(uap->clk); 2302 if (ret) 2303 return ret; 2304 2305 if (dev_get_platdata(uap->port.dev)) { 2306 struct amba_pl011_data *plat; 2307 2308 plat = dev_get_platdata(uap->port.dev); 2309 if (plat->init) 2310 plat->init(); 2311 } 2312 2313 uap->port.uartclk = clk_get_rate(uap->clk); 2314 2315 if (uap->vendor->fixed_options) { 2316 baud = uap->fixed_baud; 2317 } else { 2318 if (options) 2319 uart_parse_options(options, 2320 &baud, &parity, &bits, &flow); 2321 else 2322 pl011_console_get_options(uap, &baud, &parity, &bits); 2323 } 2324 2325 return uart_set_options(&uap->port, co, baud, parity, bits, flow); 2326 } 2327 2328 /** 2329 * pl011_console_match - non-standard console matching 2330 * @co: registering console 2331 * @name: name from console command line 2332 * @idx: index from console command line 2333 * @options: ptr to option string from console command line 2334 * 2335 * Only attempts to match console command lines of the form: 2336 * console=pl011,mmio|mmio32,<addr>[,<options>] 2337 * console=pl011,0x<addr>[,<options>] 2338 * This form is used to register an initial earlycon boot console and 2339 * replace it with the amba_console at pl011 driver init. 2340 * 2341 * Performs console setup for a match (as required by interface) 2342 * If no <options> are specified, then assume the h/w is already setup. 2343 * 2344 * Returns 0 if console matches; otherwise non-zero to use default matching 2345 */ 2346 static int pl011_console_match(struct console *co, char *name, int idx, 2347 char *options) 2348 { 2349 unsigned char iotype; 2350 resource_size_t addr; 2351 int i; 2352 2353 /* 2354 * Systems affected by the Qualcomm Technologies QDF2400 E44 erratum 2355 * have a distinct console name, so make sure we check for that. 2356 * The actual implementation of the erratum occurs in the probe 2357 * function. 2358 */ 2359 if ((strcmp(name, "qdf2400_e44") != 0) && (strcmp(name, "pl011") != 0)) 2360 return -ENODEV; 2361 2362 if (uart_parse_earlycon(options, &iotype, &addr, &options)) 2363 return -ENODEV; 2364 2365 if (iotype != UPIO_MEM && iotype != UPIO_MEM32) 2366 return -ENODEV; 2367 2368 /* try to match the port specified on the command line */ 2369 for (i = 0; i < ARRAY_SIZE(amba_ports); i++) { 2370 struct uart_port *port; 2371 2372 if (!amba_ports[i]) 2373 continue; 2374 2375 port = &amba_ports[i]->port; 2376 2377 if (port->mapbase != addr) 2378 continue; 2379 2380 co->index = i; 2381 port->cons = co; 2382 return pl011_console_setup(co, options); 2383 } 2384 2385 return -ENODEV; 2386 } 2387 2388 static struct uart_driver amba_reg; 2389 static struct console amba_console = { 2390 .name = "ttyAMA", 2391 .write = pl011_console_write, 2392 .device = uart_console_device, 2393 .setup = pl011_console_setup, 2394 .match = pl011_console_match, 2395 .flags = CON_PRINTBUFFER | CON_ANYTIME, 2396 .index = -1, 2397 .data = &amba_reg, 2398 }; 2399 2400 #define AMBA_CONSOLE (&amba_console) 2401 2402 static void qdf2400_e44_putc(struct uart_port *port, int c) 2403 { 2404 while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF) 2405 cpu_relax(); 2406 writel(c, port->membase + UART01x_DR); 2407 while (!(readl(port->membase + UART01x_FR) & UART011_FR_TXFE)) 2408 cpu_relax(); 2409 } 2410 2411 static void qdf2400_e44_early_write(struct console *con, const char *s, unsigned n) 2412 { 2413 struct earlycon_device *dev = con->data; 2414 2415 uart_console_write(&dev->port, s, n, qdf2400_e44_putc); 2416 } 2417 2418 static void pl011_putc(struct uart_port *port, int c) 2419 { 2420 while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF) 2421 cpu_relax(); 2422 if (port->iotype == UPIO_MEM32) 2423 writel(c, port->membase + UART01x_DR); 2424 else 2425 writeb(c, port->membase + UART01x_DR); 2426 while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY) 2427 cpu_relax(); 2428 } 2429 2430 static void pl011_early_write(struct console *con, const char *s, unsigned n) 2431 { 2432 struct earlycon_device *dev = con->data; 2433 2434 uart_console_write(&dev->port, s, n, pl011_putc); 2435 } 2436 2437 #ifdef CONFIG_CONSOLE_POLL 2438 static int pl011_getc(struct uart_port *port) 2439 { 2440 if (readl(port->membase + UART01x_FR) & UART01x_FR_RXFE) 2441 return NO_POLL_CHAR; 2442 2443 if (port->iotype == UPIO_MEM32) 2444 return readl(port->membase + UART01x_DR); 2445 else 2446 return readb(port->membase + UART01x_DR); 2447 } 2448 2449 static int pl011_early_read(struct console *con, char *s, unsigned int n) 2450 { 2451 struct earlycon_device *dev = con->data; 2452 int ch, num_read = 0; 2453 2454 while (num_read < n) { 2455 ch = pl011_getc(&dev->port); 2456 if (ch == NO_POLL_CHAR) 2457 break; 2458 2459 s[num_read++] = ch; 2460 } 2461 2462 return num_read; 2463 } 2464 #else 2465 #define pl011_early_read NULL 2466 #endif 2467 2468 /* 2469 * On non-ACPI systems, earlycon is enabled by specifying 2470 * "earlycon=pl011,<address>" on the kernel command line. 2471 * 2472 * On ACPI ARM64 systems, an "early" console is enabled via the SPCR table, 2473 * by specifying only "earlycon" on the command line. Because it requires 2474 * SPCR, the console starts after ACPI is parsed, which is later than a 2475 * traditional early console. 2476 * 2477 * To get the traditional early console that starts before ACPI is parsed, 2478 * specify the full "earlycon=pl011,<address>" option. 2479 */ 2480 static int __init pl011_early_console_setup(struct earlycon_device *device, 2481 const char *opt) 2482 { 2483 if (!device->port.membase) 2484 return -ENODEV; 2485 2486 device->con->write = pl011_early_write; 2487 device->con->read = pl011_early_read; 2488 2489 return 0; 2490 } 2491 OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup); 2492 OF_EARLYCON_DECLARE(pl011, "arm,sbsa-uart", pl011_early_console_setup); 2493 2494 /* 2495 * On Qualcomm Datacenter Technologies QDF2400 SOCs affected by 2496 * Erratum 44, traditional earlycon can be enabled by specifying 2497 * "earlycon=qdf2400_e44,<address>". Any options are ignored. 2498 * 2499 * Alternatively, you can just specify "earlycon", and the early console 2500 * will be enabled with the information from the SPCR table. In this 2501 * case, the SPCR code will detect the need for the E44 work-around, 2502 * and set the console name to "qdf2400_e44". 2503 */ 2504 static int __init 2505 qdf2400_e44_early_console_setup(struct earlycon_device *device, 2506 const char *opt) 2507 { 2508 if (!device->port.membase) 2509 return -ENODEV; 2510 2511 device->con->write = qdf2400_e44_early_write; 2512 return 0; 2513 } 2514 EARLYCON_DECLARE(qdf2400_e44, qdf2400_e44_early_console_setup); 2515 2516 #else 2517 #define AMBA_CONSOLE NULL 2518 #endif 2519 2520 static struct uart_driver amba_reg = { 2521 .owner = THIS_MODULE, 2522 .driver_name = "ttyAMA", 2523 .dev_name = "ttyAMA", 2524 .major = SERIAL_AMBA_MAJOR, 2525 .minor = SERIAL_AMBA_MINOR, 2526 .nr = UART_NR, 2527 .cons = AMBA_CONSOLE, 2528 }; 2529 2530 static int pl011_probe_dt_alias(int index, struct device *dev) 2531 { 2532 struct device_node *np; 2533 static bool seen_dev_with_alias = false; 2534 static bool seen_dev_without_alias = false; 2535 int ret = index; 2536 2537 if (!IS_ENABLED(CONFIG_OF)) 2538 return ret; 2539 2540 np = dev->of_node; 2541 if (!np) 2542 return ret; 2543 2544 ret = of_alias_get_id(np, "serial"); 2545 if (ret < 0) { 2546 seen_dev_without_alias = true; 2547 ret = index; 2548 } else { 2549 seen_dev_with_alias = true; 2550 if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) { 2551 dev_warn(dev, "requested serial port %d not available.\n", ret); 2552 ret = index; 2553 } 2554 } 2555 2556 if (seen_dev_with_alias && seen_dev_without_alias) 2557 dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n"); 2558 2559 return ret; 2560 } 2561 2562 /* unregisters the driver also if no more ports are left */ 2563 static void pl011_unregister_port(struct uart_amba_port *uap) 2564 { 2565 int i; 2566 bool busy = false; 2567 2568 for (i = 0; i < ARRAY_SIZE(amba_ports); i++) { 2569 if (amba_ports[i] == uap) 2570 amba_ports[i] = NULL; 2571 else if (amba_ports[i]) 2572 busy = true; 2573 } 2574 pl011_dma_remove(uap); 2575 if (!busy) 2576 uart_unregister_driver(&amba_reg); 2577 } 2578 2579 static int pl011_find_free_port(void) 2580 { 2581 int i; 2582 2583 for (i = 0; i < ARRAY_SIZE(amba_ports); i++) 2584 if (amba_ports[i] == NULL) 2585 return i; 2586 2587 return -EBUSY; 2588 } 2589 2590 static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap, 2591 struct resource *mmiobase, int index) 2592 { 2593 void __iomem *base; 2594 2595 base = devm_ioremap_resource(dev, mmiobase); 2596 if (IS_ERR(base)) 2597 return PTR_ERR(base); 2598 2599 index = pl011_probe_dt_alias(index, dev); 2600 2601 uap->old_cr = 0; 2602 uap->port.dev = dev; 2603 uap->port.mapbase = mmiobase->start; 2604 uap->port.membase = base; 2605 uap->port.fifosize = uap->fifosize; 2606 uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL011_CONSOLE); 2607 uap->port.flags = UPF_BOOT_AUTOCONF; 2608 uap->port.line = index; 2609 2610 amba_ports[index] = uap; 2611 2612 return 0; 2613 } 2614 2615 static int pl011_register_port(struct uart_amba_port *uap) 2616 { 2617 int ret, i; 2618 2619 /* Ensure interrupts from this UART are masked and cleared */ 2620 pl011_write(0, uap, REG_IMSC); 2621 pl011_write(0xffff, uap, REG_ICR); 2622 2623 if (!amba_reg.state) { 2624 ret = uart_register_driver(&amba_reg); 2625 if (ret < 0) { 2626 dev_err(uap->port.dev, 2627 "Failed to register AMBA-PL011 driver\n"); 2628 for (i = 0; i < ARRAY_SIZE(amba_ports); i++) 2629 if (amba_ports[i] == uap) 2630 amba_ports[i] = NULL; 2631 return ret; 2632 } 2633 } 2634 2635 ret = uart_add_one_port(&amba_reg, &uap->port); 2636 if (ret) 2637 pl011_unregister_port(uap); 2638 2639 return ret; 2640 } 2641 2642 static int pl011_probe(struct amba_device *dev, const struct amba_id *id) 2643 { 2644 struct uart_amba_port *uap; 2645 struct vendor_data *vendor = id->data; 2646 int portnr, ret; 2647 2648 portnr = pl011_find_free_port(); 2649 if (portnr < 0) 2650 return portnr; 2651 2652 uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port), 2653 GFP_KERNEL); 2654 if (!uap) 2655 return -ENOMEM; 2656 2657 uap->clk = devm_clk_get(&dev->dev, NULL); 2658 if (IS_ERR(uap->clk)) 2659 return PTR_ERR(uap->clk); 2660 2661 uap->reg_offset = vendor->reg_offset; 2662 uap->vendor = vendor; 2663 uap->fifosize = vendor->get_fifosize(dev); 2664 uap->port.iotype = vendor->access_32b ? UPIO_MEM32 : UPIO_MEM; 2665 uap->port.irq = dev->irq[0]; 2666 uap->port.ops = &amba_pl011_pops; 2667 2668 snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev)); 2669 2670 ret = pl011_setup_port(&dev->dev, uap, &dev->res, portnr); 2671 if (ret) 2672 return ret; 2673 2674 amba_set_drvdata(dev, uap); 2675 2676 return pl011_register_port(uap); 2677 } 2678 2679 static int pl011_remove(struct amba_device *dev) 2680 { 2681 struct uart_amba_port *uap = amba_get_drvdata(dev); 2682 2683 uart_remove_one_port(&amba_reg, &uap->port); 2684 pl011_unregister_port(uap); 2685 return 0; 2686 } 2687 2688 #ifdef CONFIG_PM_SLEEP 2689 static int pl011_suspend(struct device *dev) 2690 { 2691 struct uart_amba_port *uap = dev_get_drvdata(dev); 2692 2693 if (!uap) 2694 return -EINVAL; 2695 2696 return uart_suspend_port(&amba_reg, &uap->port); 2697 } 2698 2699 static int pl011_resume(struct device *dev) 2700 { 2701 struct uart_amba_port *uap = dev_get_drvdata(dev); 2702 2703 if (!uap) 2704 return -EINVAL; 2705 2706 return uart_resume_port(&amba_reg, &uap->port); 2707 } 2708 #endif 2709 2710 static SIMPLE_DEV_PM_OPS(pl011_dev_pm_ops, pl011_suspend, pl011_resume); 2711 2712 static int sbsa_uart_probe(struct platform_device *pdev) 2713 { 2714 struct uart_amba_port *uap; 2715 struct resource *r; 2716 int portnr, ret; 2717 int baudrate; 2718 2719 /* 2720 * Check the mandatory baud rate parameter in the DT node early 2721 * so that we can easily exit with the error. 2722 */ 2723 if (pdev->dev.of_node) { 2724 struct device_node *np = pdev->dev.of_node; 2725 2726 ret = of_property_read_u32(np, "current-speed", &baudrate); 2727 if (ret) 2728 return ret; 2729 } else { 2730 baudrate = 115200; 2731 } 2732 2733 portnr = pl011_find_free_port(); 2734 if (portnr < 0) 2735 return portnr; 2736 2737 uap = devm_kzalloc(&pdev->dev, sizeof(struct uart_amba_port), 2738 GFP_KERNEL); 2739 if (!uap) 2740 return -ENOMEM; 2741 2742 ret = platform_get_irq(pdev, 0); 2743 if (ret < 0) 2744 return ret; 2745 uap->port.irq = ret; 2746 2747 #ifdef CONFIG_ACPI_SPCR_TABLE 2748 if (qdf2400_e44_present) { 2749 dev_info(&pdev->dev, "working around QDF2400 SoC erratum 44\n"); 2750 uap->vendor = &vendor_qdt_qdf2400_e44; 2751 } else 2752 #endif 2753 uap->vendor = &vendor_sbsa; 2754 2755 uap->reg_offset = uap->vendor->reg_offset; 2756 uap->fifosize = 32; 2757 uap->port.iotype = uap->vendor->access_32b ? UPIO_MEM32 : UPIO_MEM; 2758 uap->port.ops = &sbsa_uart_pops; 2759 uap->fixed_baud = baudrate; 2760 2761 snprintf(uap->type, sizeof(uap->type), "SBSA"); 2762 2763 r = platform_get_resource(pdev, IORESOURCE_MEM, 0); 2764 2765 ret = pl011_setup_port(&pdev->dev, uap, r, portnr); 2766 if (ret) 2767 return ret; 2768 2769 platform_set_drvdata(pdev, uap); 2770 2771 return pl011_register_port(uap); 2772 } 2773 2774 static int sbsa_uart_remove(struct platform_device *pdev) 2775 { 2776 struct uart_amba_port *uap = platform_get_drvdata(pdev); 2777 2778 uart_remove_one_port(&amba_reg, &uap->port); 2779 pl011_unregister_port(uap); 2780 return 0; 2781 } 2782 2783 static const struct of_device_id sbsa_uart_of_match[] = { 2784 { .compatible = "arm,sbsa-uart", }, 2785 {}, 2786 }; 2787 MODULE_DEVICE_TABLE(of, sbsa_uart_of_match); 2788 2789 static const struct acpi_device_id sbsa_uart_acpi_match[] = { 2790 { "ARMH0011", 0 }, 2791 {}, 2792 }; 2793 MODULE_DEVICE_TABLE(acpi, sbsa_uart_acpi_match); 2794 2795 static struct platform_driver arm_sbsa_uart_platform_driver = { 2796 .probe = sbsa_uart_probe, 2797 .remove = sbsa_uart_remove, 2798 .driver = { 2799 .name = "sbsa-uart", 2800 .pm = &pl011_dev_pm_ops, 2801 .of_match_table = of_match_ptr(sbsa_uart_of_match), 2802 .acpi_match_table = ACPI_PTR(sbsa_uart_acpi_match), 2803 .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011), 2804 }, 2805 }; 2806 2807 static const struct amba_id pl011_ids[] = { 2808 { 2809 .id = 0x00041011, 2810 .mask = 0x000fffff, 2811 .data = &vendor_arm, 2812 }, 2813 { 2814 .id = 0x00380802, 2815 .mask = 0x00ffffff, 2816 .data = &vendor_st, 2817 }, 2818 { 2819 .id = AMBA_LINUX_ID(0x00, 0x1, 0xffe), 2820 .mask = 0x00ffffff, 2821 .data = &vendor_zte, 2822 }, 2823 { 0, 0 }, 2824 }; 2825 2826 MODULE_DEVICE_TABLE(amba, pl011_ids); 2827 2828 static struct amba_driver pl011_driver = { 2829 .drv = { 2830 .name = "uart-pl011", 2831 .pm = &pl011_dev_pm_ops, 2832 .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011), 2833 }, 2834 .id_table = pl011_ids, 2835 .probe = pl011_probe, 2836 .remove = pl011_remove, 2837 }; 2838 2839 static int __init pl011_init(void) 2840 { 2841 printk(KERN_INFO "Serial: AMBA PL011 UART driver\n"); 2842 2843 if (platform_driver_register(&arm_sbsa_uart_platform_driver)) 2844 pr_warn("could not register SBSA UART platform driver\n"); 2845 return amba_driver_register(&pl011_driver); 2846 } 2847 2848 static void __exit pl011_exit(void) 2849 { 2850 platform_driver_unregister(&arm_sbsa_uart_platform_driver); 2851 amba_driver_unregister(&pl011_driver); 2852 } 2853 2854 /* 2855 * While this can be a module, if builtin it's most likely the console 2856 * So let's leave module_exit but move module_init to an earlier place 2857 */ 2858 arch_initcall(pl011_init); 2859 module_exit(pl011_exit); 2860 2861 MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd"); 2862 MODULE_DESCRIPTION("ARM AMBA serial port driver"); 2863 MODULE_LICENSE("GPL"); 2864