1 /* 2 * SuperH on-chip serial module support. (SCI with no FIFO / with FIFO) 3 * 4 * Copyright (C) 2002 - 2011 Paul Mundt 5 * Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007). 6 * 7 * based off of the old drivers/char/sh-sci.c by: 8 * 9 * Copyright (C) 1999, 2000 Niibe Yutaka 10 * Copyright (C) 2000 Sugioka Toshinobu 11 * Modified to support multiple serial ports. Stuart Menefy (May 2000). 12 * Modified to support SecureEdge. David McCullough (2002) 13 * Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003). 14 * Removed SH7300 support (Jul 2007). 15 * 16 * This file is subject to the terms and conditions of the GNU General Public 17 * License. See the file "COPYING" in the main directory of this archive 18 * for more details. 19 */ 20 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) 21 #define SUPPORT_SYSRQ 22 #endif 23 24 #undef DEBUG 25 26 #include <linux/clk.h> 27 #include <linux/console.h> 28 #include <linux/ctype.h> 29 #include <linux/cpufreq.h> 30 #include <linux/delay.h> 31 #include <linux/dmaengine.h> 32 #include <linux/dma-mapping.h> 33 #include <linux/err.h> 34 #include <linux/errno.h> 35 #include <linux/init.h> 36 #include <linux/interrupt.h> 37 #include <linux/ioport.h> 38 #include <linux/major.h> 39 #include <linux/module.h> 40 #include <linux/mm.h> 41 #include <linux/notifier.h> 42 #include <linux/of.h> 43 #include <linux/platform_device.h> 44 #include <linux/pm_runtime.h> 45 #include <linux/scatterlist.h> 46 #include <linux/serial.h> 47 #include <linux/serial_sci.h> 48 #include <linux/sh_dma.h> 49 #include <linux/slab.h> 50 #include <linux/string.h> 51 #include <linux/sysrq.h> 52 #include <linux/timer.h> 53 #include <linux/tty.h> 54 #include <linux/tty_flip.h> 55 56 #ifdef CONFIG_SUPERH 57 #include <asm/sh_bios.h> 58 #endif 59 60 #include "sh-sci.h" 61 62 /* Offsets into the sci_port->irqs array */ 63 enum { 64 SCIx_ERI_IRQ, 65 SCIx_RXI_IRQ, 66 SCIx_TXI_IRQ, 67 SCIx_BRI_IRQ, 68 SCIx_NR_IRQS, 69 70 SCIx_MUX_IRQ = SCIx_NR_IRQS, /* special case */ 71 }; 72 73 #define SCIx_IRQ_IS_MUXED(port) \ 74 ((port)->irqs[SCIx_ERI_IRQ] == \ 75 (port)->irqs[SCIx_RXI_IRQ]) || \ 76 ((port)->irqs[SCIx_ERI_IRQ] && \ 77 ((port)->irqs[SCIx_RXI_IRQ] < 0)) 78 79 struct sci_port { 80 struct uart_port port; 81 82 /* Platform configuration */ 83 struct plat_sci_port *cfg; 84 int overrun_bit; 85 unsigned int error_mask; 86 unsigned int sampling_rate; 87 88 89 /* Break timer */ 90 struct timer_list break_timer; 91 int break_flag; 92 93 /* Interface clock */ 94 struct clk *iclk; 95 /* Function clock */ 96 struct clk *fclk; 97 98 int irqs[SCIx_NR_IRQS]; 99 char *irqstr[SCIx_NR_IRQS]; 100 101 struct dma_chan *chan_tx; 102 struct dma_chan *chan_rx; 103 104 #ifdef CONFIG_SERIAL_SH_SCI_DMA 105 struct dma_async_tx_descriptor *desc_tx; 106 struct dma_async_tx_descriptor *desc_rx[2]; 107 dma_cookie_t cookie_tx; 108 dma_cookie_t cookie_rx[2]; 109 dma_cookie_t active_rx; 110 struct scatterlist sg_tx; 111 unsigned int sg_len_tx; 112 struct scatterlist sg_rx[2]; 113 size_t buf_len_rx; 114 struct sh_dmae_slave param_tx; 115 struct sh_dmae_slave param_rx; 116 struct work_struct work_tx; 117 struct work_struct work_rx; 118 struct timer_list rx_timer; 119 unsigned int rx_timeout; 120 #endif 121 122 struct notifier_block freq_transition; 123 }; 124 125 /* Function prototypes */ 126 static void sci_start_tx(struct uart_port *port); 127 static void sci_stop_tx(struct uart_port *port); 128 static void sci_start_rx(struct uart_port *port); 129 130 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS 131 132 static struct sci_port sci_ports[SCI_NPORTS]; 133 static struct uart_driver sci_uart_driver; 134 135 static inline struct sci_port * 136 to_sci_port(struct uart_port *uart) 137 { 138 return container_of(uart, struct sci_port, port); 139 } 140 141 struct plat_sci_reg { 142 u8 offset, size; 143 }; 144 145 /* Helper for invalidating specific entries of an inherited map. */ 146 #define sci_reg_invalid { .offset = 0, .size = 0 } 147 148 static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = { 149 [SCIx_PROBE_REGTYPE] = { 150 [0 ... SCIx_NR_REGS - 1] = sci_reg_invalid, 151 }, 152 153 /* 154 * Common SCI definitions, dependent on the port's regshift 155 * value. 156 */ 157 [SCIx_SCI_REGTYPE] = { 158 [SCSMR] = { 0x00, 8 }, 159 [SCBRR] = { 0x01, 8 }, 160 [SCSCR] = { 0x02, 8 }, 161 [SCxTDR] = { 0x03, 8 }, 162 [SCxSR] = { 0x04, 8 }, 163 [SCxRDR] = { 0x05, 8 }, 164 [SCFCR] = sci_reg_invalid, 165 [SCFDR] = sci_reg_invalid, 166 [SCTFDR] = sci_reg_invalid, 167 [SCRFDR] = sci_reg_invalid, 168 [SCSPTR] = sci_reg_invalid, 169 [SCLSR] = sci_reg_invalid, 170 [HSSRR] = sci_reg_invalid, 171 }, 172 173 /* 174 * Common definitions for legacy IrDA ports, dependent on 175 * regshift value. 176 */ 177 [SCIx_IRDA_REGTYPE] = { 178 [SCSMR] = { 0x00, 8 }, 179 [SCBRR] = { 0x01, 8 }, 180 [SCSCR] = { 0x02, 8 }, 181 [SCxTDR] = { 0x03, 8 }, 182 [SCxSR] = { 0x04, 8 }, 183 [SCxRDR] = { 0x05, 8 }, 184 [SCFCR] = { 0x06, 8 }, 185 [SCFDR] = { 0x07, 16 }, 186 [SCTFDR] = sci_reg_invalid, 187 [SCRFDR] = sci_reg_invalid, 188 [SCSPTR] = sci_reg_invalid, 189 [SCLSR] = sci_reg_invalid, 190 [HSSRR] = sci_reg_invalid, 191 }, 192 193 /* 194 * Common SCIFA definitions. 195 */ 196 [SCIx_SCIFA_REGTYPE] = { 197 [SCSMR] = { 0x00, 16 }, 198 [SCBRR] = { 0x04, 8 }, 199 [SCSCR] = { 0x08, 16 }, 200 [SCxTDR] = { 0x20, 8 }, 201 [SCxSR] = { 0x14, 16 }, 202 [SCxRDR] = { 0x24, 8 }, 203 [SCFCR] = { 0x18, 16 }, 204 [SCFDR] = { 0x1c, 16 }, 205 [SCTFDR] = sci_reg_invalid, 206 [SCRFDR] = sci_reg_invalid, 207 [SCSPTR] = sci_reg_invalid, 208 [SCLSR] = sci_reg_invalid, 209 [HSSRR] = sci_reg_invalid, 210 }, 211 212 /* 213 * Common SCIFB definitions. 214 */ 215 [SCIx_SCIFB_REGTYPE] = { 216 [SCSMR] = { 0x00, 16 }, 217 [SCBRR] = { 0x04, 8 }, 218 [SCSCR] = { 0x08, 16 }, 219 [SCxTDR] = { 0x40, 8 }, 220 [SCxSR] = { 0x14, 16 }, 221 [SCxRDR] = { 0x60, 8 }, 222 [SCFCR] = { 0x18, 16 }, 223 [SCFDR] = sci_reg_invalid, 224 [SCTFDR] = { 0x38, 16 }, 225 [SCRFDR] = { 0x3c, 16 }, 226 [SCSPTR] = sci_reg_invalid, 227 [SCLSR] = sci_reg_invalid, 228 [HSSRR] = sci_reg_invalid, 229 }, 230 231 /* 232 * Common SH-2(A) SCIF definitions for ports with FIFO data 233 * count registers. 234 */ 235 [SCIx_SH2_SCIF_FIFODATA_REGTYPE] = { 236 [SCSMR] = { 0x00, 16 }, 237 [SCBRR] = { 0x04, 8 }, 238 [SCSCR] = { 0x08, 16 }, 239 [SCxTDR] = { 0x0c, 8 }, 240 [SCxSR] = { 0x10, 16 }, 241 [SCxRDR] = { 0x14, 8 }, 242 [SCFCR] = { 0x18, 16 }, 243 [SCFDR] = { 0x1c, 16 }, 244 [SCTFDR] = sci_reg_invalid, 245 [SCRFDR] = sci_reg_invalid, 246 [SCSPTR] = { 0x20, 16 }, 247 [SCLSR] = { 0x24, 16 }, 248 [HSSRR] = sci_reg_invalid, 249 }, 250 251 /* 252 * Common SH-3 SCIF definitions. 253 */ 254 [SCIx_SH3_SCIF_REGTYPE] = { 255 [SCSMR] = { 0x00, 8 }, 256 [SCBRR] = { 0x02, 8 }, 257 [SCSCR] = { 0x04, 8 }, 258 [SCxTDR] = { 0x06, 8 }, 259 [SCxSR] = { 0x08, 16 }, 260 [SCxRDR] = { 0x0a, 8 }, 261 [SCFCR] = { 0x0c, 8 }, 262 [SCFDR] = { 0x0e, 16 }, 263 [SCTFDR] = sci_reg_invalid, 264 [SCRFDR] = sci_reg_invalid, 265 [SCSPTR] = sci_reg_invalid, 266 [SCLSR] = sci_reg_invalid, 267 [HSSRR] = sci_reg_invalid, 268 }, 269 270 /* 271 * Common SH-4(A) SCIF(B) definitions. 272 */ 273 [SCIx_SH4_SCIF_REGTYPE] = { 274 [SCSMR] = { 0x00, 16 }, 275 [SCBRR] = { 0x04, 8 }, 276 [SCSCR] = { 0x08, 16 }, 277 [SCxTDR] = { 0x0c, 8 }, 278 [SCxSR] = { 0x10, 16 }, 279 [SCxRDR] = { 0x14, 8 }, 280 [SCFCR] = { 0x18, 16 }, 281 [SCFDR] = { 0x1c, 16 }, 282 [SCTFDR] = sci_reg_invalid, 283 [SCRFDR] = sci_reg_invalid, 284 [SCSPTR] = { 0x20, 16 }, 285 [SCLSR] = { 0x24, 16 }, 286 [HSSRR] = sci_reg_invalid, 287 }, 288 289 /* 290 * Common HSCIF definitions. 291 */ 292 [SCIx_HSCIF_REGTYPE] = { 293 [SCSMR] = { 0x00, 16 }, 294 [SCBRR] = { 0x04, 8 }, 295 [SCSCR] = { 0x08, 16 }, 296 [SCxTDR] = { 0x0c, 8 }, 297 [SCxSR] = { 0x10, 16 }, 298 [SCxRDR] = { 0x14, 8 }, 299 [SCFCR] = { 0x18, 16 }, 300 [SCFDR] = { 0x1c, 16 }, 301 [SCTFDR] = sci_reg_invalid, 302 [SCRFDR] = sci_reg_invalid, 303 [SCSPTR] = { 0x20, 16 }, 304 [SCLSR] = { 0x24, 16 }, 305 [HSSRR] = { 0x40, 16 }, 306 }, 307 308 /* 309 * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR 310 * register. 311 */ 312 [SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = { 313 [SCSMR] = { 0x00, 16 }, 314 [SCBRR] = { 0x04, 8 }, 315 [SCSCR] = { 0x08, 16 }, 316 [SCxTDR] = { 0x0c, 8 }, 317 [SCxSR] = { 0x10, 16 }, 318 [SCxRDR] = { 0x14, 8 }, 319 [SCFCR] = { 0x18, 16 }, 320 [SCFDR] = { 0x1c, 16 }, 321 [SCTFDR] = sci_reg_invalid, 322 [SCRFDR] = sci_reg_invalid, 323 [SCSPTR] = sci_reg_invalid, 324 [SCLSR] = { 0x24, 16 }, 325 [HSSRR] = sci_reg_invalid, 326 }, 327 328 /* 329 * Common SH-4(A) SCIF(B) definitions for ports with FIFO data 330 * count registers. 331 */ 332 [SCIx_SH4_SCIF_FIFODATA_REGTYPE] = { 333 [SCSMR] = { 0x00, 16 }, 334 [SCBRR] = { 0x04, 8 }, 335 [SCSCR] = { 0x08, 16 }, 336 [SCxTDR] = { 0x0c, 8 }, 337 [SCxSR] = { 0x10, 16 }, 338 [SCxRDR] = { 0x14, 8 }, 339 [SCFCR] = { 0x18, 16 }, 340 [SCFDR] = { 0x1c, 16 }, 341 [SCTFDR] = { 0x1c, 16 }, /* aliased to SCFDR */ 342 [SCRFDR] = { 0x20, 16 }, 343 [SCSPTR] = { 0x24, 16 }, 344 [SCLSR] = { 0x28, 16 }, 345 [HSSRR] = sci_reg_invalid, 346 }, 347 348 /* 349 * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR 350 * registers. 351 */ 352 [SCIx_SH7705_SCIF_REGTYPE] = { 353 [SCSMR] = { 0x00, 16 }, 354 [SCBRR] = { 0x04, 8 }, 355 [SCSCR] = { 0x08, 16 }, 356 [SCxTDR] = { 0x20, 8 }, 357 [SCxSR] = { 0x14, 16 }, 358 [SCxRDR] = { 0x24, 8 }, 359 [SCFCR] = { 0x18, 16 }, 360 [SCFDR] = { 0x1c, 16 }, 361 [SCTFDR] = sci_reg_invalid, 362 [SCRFDR] = sci_reg_invalid, 363 [SCSPTR] = sci_reg_invalid, 364 [SCLSR] = sci_reg_invalid, 365 [HSSRR] = sci_reg_invalid, 366 }, 367 }; 368 369 #define sci_getreg(up, offset) (sci_regmap[to_sci_port(up)->cfg->regtype] + offset) 370 371 /* 372 * The "offset" here is rather misleading, in that it refers to an enum 373 * value relative to the port mapping rather than the fixed offset 374 * itself, which needs to be manually retrieved from the platform's 375 * register map for the given port. 376 */ 377 static unsigned int sci_serial_in(struct uart_port *p, int offset) 378 { 379 struct plat_sci_reg *reg = sci_getreg(p, offset); 380 381 if (reg->size == 8) 382 return ioread8(p->membase + (reg->offset << p->regshift)); 383 else if (reg->size == 16) 384 return ioread16(p->membase + (reg->offset << p->regshift)); 385 else 386 WARN(1, "Invalid register access\n"); 387 388 return 0; 389 } 390 391 static void sci_serial_out(struct uart_port *p, int offset, int value) 392 { 393 struct plat_sci_reg *reg = sci_getreg(p, offset); 394 395 if (reg->size == 8) 396 iowrite8(value, p->membase + (reg->offset << p->regshift)); 397 else if (reg->size == 16) 398 iowrite16(value, p->membase + (reg->offset << p->regshift)); 399 else 400 WARN(1, "Invalid register access\n"); 401 } 402 403 static int sci_probe_regmap(struct plat_sci_port *cfg) 404 { 405 switch (cfg->type) { 406 case PORT_SCI: 407 cfg->regtype = SCIx_SCI_REGTYPE; 408 break; 409 case PORT_IRDA: 410 cfg->regtype = SCIx_IRDA_REGTYPE; 411 break; 412 case PORT_SCIFA: 413 cfg->regtype = SCIx_SCIFA_REGTYPE; 414 break; 415 case PORT_SCIFB: 416 cfg->regtype = SCIx_SCIFB_REGTYPE; 417 break; 418 case PORT_SCIF: 419 /* 420 * The SH-4 is a bit of a misnomer here, although that's 421 * where this particular port layout originated. This 422 * configuration (or some slight variation thereof) 423 * remains the dominant model for all SCIFs. 424 */ 425 cfg->regtype = SCIx_SH4_SCIF_REGTYPE; 426 break; 427 case PORT_HSCIF: 428 cfg->regtype = SCIx_HSCIF_REGTYPE; 429 break; 430 default: 431 pr_err("Can't probe register map for given port\n"); 432 return -EINVAL; 433 } 434 435 return 0; 436 } 437 438 static void sci_port_enable(struct sci_port *sci_port) 439 { 440 if (!sci_port->port.dev) 441 return; 442 443 pm_runtime_get_sync(sci_port->port.dev); 444 445 clk_prepare_enable(sci_port->iclk); 446 sci_port->port.uartclk = clk_get_rate(sci_port->iclk); 447 clk_prepare_enable(sci_port->fclk); 448 } 449 450 static void sci_port_disable(struct sci_port *sci_port) 451 { 452 if (!sci_port->port.dev) 453 return; 454 455 /* Cancel the break timer to ensure that the timer handler will not try 456 * to access the hardware with clocks and power disabled. Reset the 457 * break flag to make the break debouncing state machine ready for the 458 * next break. 459 */ 460 del_timer_sync(&sci_port->break_timer); 461 sci_port->break_flag = 0; 462 463 clk_disable_unprepare(sci_port->fclk); 464 clk_disable_unprepare(sci_port->iclk); 465 466 pm_runtime_put_sync(sci_port->port.dev); 467 } 468 469 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) 470 471 #ifdef CONFIG_CONSOLE_POLL 472 static int sci_poll_get_char(struct uart_port *port) 473 { 474 unsigned short status; 475 int c; 476 477 do { 478 status = serial_port_in(port, SCxSR); 479 if (status & SCxSR_ERRORS(port)) { 480 serial_port_out(port, SCxSR, SCxSR_ERROR_CLEAR(port)); 481 continue; 482 } 483 break; 484 } while (1); 485 486 if (!(status & SCxSR_RDxF(port))) 487 return NO_POLL_CHAR; 488 489 c = serial_port_in(port, SCxRDR); 490 491 /* Dummy read */ 492 serial_port_in(port, SCxSR); 493 serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); 494 495 return c; 496 } 497 #endif 498 499 static void sci_poll_put_char(struct uart_port *port, unsigned char c) 500 { 501 unsigned short status; 502 503 do { 504 status = serial_port_in(port, SCxSR); 505 } while (!(status & SCxSR_TDxE(port))); 506 507 serial_port_out(port, SCxTDR, c); 508 serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port)); 509 } 510 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */ 511 512 static void sci_init_pins(struct uart_port *port, unsigned int cflag) 513 { 514 struct sci_port *s = to_sci_port(port); 515 struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR; 516 517 /* 518 * Use port-specific handler if provided. 519 */ 520 if (s->cfg->ops && s->cfg->ops->init_pins) { 521 s->cfg->ops->init_pins(port, cflag); 522 return; 523 } 524 525 /* 526 * For the generic path SCSPTR is necessary. Bail out if that's 527 * unavailable, too. 528 */ 529 if (!reg->size) 530 return; 531 532 if ((s->cfg->capabilities & SCIx_HAVE_RTSCTS) && 533 ((!(cflag & CRTSCTS)))) { 534 unsigned short status; 535 536 status = serial_port_in(port, SCSPTR); 537 status &= ~SCSPTR_CTSIO; 538 status |= SCSPTR_RTSIO; 539 serial_port_out(port, SCSPTR, status); /* Set RTS = 1 */ 540 } 541 } 542 543 static int sci_txfill(struct uart_port *port) 544 { 545 struct plat_sci_reg *reg; 546 547 reg = sci_getreg(port, SCTFDR); 548 if (reg->size) 549 return serial_port_in(port, SCTFDR) & ((port->fifosize << 1) - 1); 550 551 reg = sci_getreg(port, SCFDR); 552 if (reg->size) 553 return serial_port_in(port, SCFDR) >> 8; 554 555 return !(serial_port_in(port, SCxSR) & SCI_TDRE); 556 } 557 558 static int sci_txroom(struct uart_port *port) 559 { 560 return port->fifosize - sci_txfill(port); 561 } 562 563 static int sci_rxfill(struct uart_port *port) 564 { 565 struct plat_sci_reg *reg; 566 567 reg = sci_getreg(port, SCRFDR); 568 if (reg->size) 569 return serial_port_in(port, SCRFDR) & ((port->fifosize << 1) - 1); 570 571 reg = sci_getreg(port, SCFDR); 572 if (reg->size) 573 return serial_port_in(port, SCFDR) & ((port->fifosize << 1) - 1); 574 575 return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0; 576 } 577 578 /* 579 * SCI helper for checking the state of the muxed port/RXD pins. 580 */ 581 static inline int sci_rxd_in(struct uart_port *port) 582 { 583 struct sci_port *s = to_sci_port(port); 584 585 if (s->cfg->port_reg <= 0) 586 return 1; 587 588 /* Cast for ARM damage */ 589 return !!__raw_readb((void __iomem *)(uintptr_t)s->cfg->port_reg); 590 } 591 592 /* ********************************************************************** * 593 * the interrupt related routines * 594 * ********************************************************************** */ 595 596 static void sci_transmit_chars(struct uart_port *port) 597 { 598 struct circ_buf *xmit = &port->state->xmit; 599 unsigned int stopped = uart_tx_stopped(port); 600 unsigned short status; 601 unsigned short ctrl; 602 int count; 603 604 status = serial_port_in(port, SCxSR); 605 if (!(status & SCxSR_TDxE(port))) { 606 ctrl = serial_port_in(port, SCSCR); 607 if (uart_circ_empty(xmit)) 608 ctrl &= ~SCSCR_TIE; 609 else 610 ctrl |= SCSCR_TIE; 611 serial_port_out(port, SCSCR, ctrl); 612 return; 613 } 614 615 count = sci_txroom(port); 616 617 do { 618 unsigned char c; 619 620 if (port->x_char) { 621 c = port->x_char; 622 port->x_char = 0; 623 } else if (!uart_circ_empty(xmit) && !stopped) { 624 c = xmit->buf[xmit->tail]; 625 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); 626 } else { 627 break; 628 } 629 630 serial_port_out(port, SCxTDR, c); 631 632 port->icount.tx++; 633 } while (--count > 0); 634 635 serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port)); 636 637 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 638 uart_write_wakeup(port); 639 if (uart_circ_empty(xmit)) { 640 sci_stop_tx(port); 641 } else { 642 ctrl = serial_port_in(port, SCSCR); 643 644 if (port->type != PORT_SCI) { 645 serial_port_in(port, SCxSR); /* Dummy read */ 646 serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port)); 647 } 648 649 ctrl |= SCSCR_TIE; 650 serial_port_out(port, SCSCR, ctrl); 651 } 652 } 653 654 /* On SH3, SCIF may read end-of-break as a space->mark char */ 655 #define STEPFN(c) ({int __c = (c); (((__c-1)|(__c)) == -1); }) 656 657 static void sci_receive_chars(struct uart_port *port) 658 { 659 struct sci_port *sci_port = to_sci_port(port); 660 struct tty_port *tport = &port->state->port; 661 int i, count, copied = 0; 662 unsigned short status; 663 unsigned char flag; 664 665 status = serial_port_in(port, SCxSR); 666 if (!(status & SCxSR_RDxF(port))) 667 return; 668 669 while (1) { 670 /* Don't copy more bytes than there is room for in the buffer */ 671 count = tty_buffer_request_room(tport, sci_rxfill(port)); 672 673 /* If for any reason we can't copy more data, we're done! */ 674 if (count == 0) 675 break; 676 677 if (port->type == PORT_SCI) { 678 char c = serial_port_in(port, SCxRDR); 679 if (uart_handle_sysrq_char(port, c) || 680 sci_port->break_flag) 681 count = 0; 682 else 683 tty_insert_flip_char(tport, c, TTY_NORMAL); 684 } else { 685 for (i = 0; i < count; i++) { 686 char c = serial_port_in(port, SCxRDR); 687 688 status = serial_port_in(port, SCxSR); 689 #if defined(CONFIG_CPU_SH3) 690 /* Skip "chars" during break */ 691 if (sci_port->break_flag) { 692 if ((c == 0) && 693 (status & SCxSR_FER(port))) { 694 count--; i--; 695 continue; 696 } 697 698 /* Nonzero => end-of-break */ 699 dev_dbg(port->dev, "debounce<%02x>\n", c); 700 sci_port->break_flag = 0; 701 702 if (STEPFN(c)) { 703 count--; i--; 704 continue; 705 } 706 } 707 #endif /* CONFIG_CPU_SH3 */ 708 if (uart_handle_sysrq_char(port, c)) { 709 count--; i--; 710 continue; 711 } 712 713 /* Store data and status */ 714 if (status & SCxSR_FER(port)) { 715 flag = TTY_FRAME; 716 port->icount.frame++; 717 dev_notice(port->dev, "frame error\n"); 718 } else if (status & SCxSR_PER(port)) { 719 flag = TTY_PARITY; 720 port->icount.parity++; 721 dev_notice(port->dev, "parity error\n"); 722 } else 723 flag = TTY_NORMAL; 724 725 tty_insert_flip_char(tport, c, flag); 726 } 727 } 728 729 serial_port_in(port, SCxSR); /* dummy read */ 730 serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); 731 732 copied += count; 733 port->icount.rx += count; 734 } 735 736 if (copied) { 737 /* Tell the rest of the system the news. New characters! */ 738 tty_flip_buffer_push(tport); 739 } else { 740 serial_port_in(port, SCxSR); /* dummy read */ 741 serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); 742 } 743 } 744 745 #define SCI_BREAK_JIFFIES (HZ/20) 746 747 /* 748 * The sci generates interrupts during the break, 749 * 1 per millisecond or so during the break period, for 9600 baud. 750 * So dont bother disabling interrupts. 751 * But dont want more than 1 break event. 752 * Use a kernel timer to periodically poll the rx line until 753 * the break is finished. 754 */ 755 static inline void sci_schedule_break_timer(struct sci_port *port) 756 { 757 mod_timer(&port->break_timer, jiffies + SCI_BREAK_JIFFIES); 758 } 759 760 /* Ensure that two consecutive samples find the break over. */ 761 static void sci_break_timer(unsigned long data) 762 { 763 struct sci_port *port = (struct sci_port *)data; 764 765 if (sci_rxd_in(&port->port) == 0) { 766 port->break_flag = 1; 767 sci_schedule_break_timer(port); 768 } else if (port->break_flag == 1) { 769 /* break is over. */ 770 port->break_flag = 2; 771 sci_schedule_break_timer(port); 772 } else 773 port->break_flag = 0; 774 } 775 776 static int sci_handle_errors(struct uart_port *port) 777 { 778 int copied = 0; 779 unsigned short status = serial_port_in(port, SCxSR); 780 struct tty_port *tport = &port->state->port; 781 struct sci_port *s = to_sci_port(port); 782 783 /* Handle overruns */ 784 if (status & (1 << s->overrun_bit)) { 785 port->icount.overrun++; 786 787 /* overrun error */ 788 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN)) 789 copied++; 790 791 dev_notice(port->dev, "overrun error\n"); 792 } 793 794 if (status & SCxSR_FER(port)) { 795 if (sci_rxd_in(port) == 0) { 796 /* Notify of BREAK */ 797 struct sci_port *sci_port = to_sci_port(port); 798 799 if (!sci_port->break_flag) { 800 port->icount.brk++; 801 802 sci_port->break_flag = 1; 803 sci_schedule_break_timer(sci_port); 804 805 /* Do sysrq handling. */ 806 if (uart_handle_break(port)) 807 return 0; 808 809 dev_dbg(port->dev, "BREAK detected\n"); 810 811 if (tty_insert_flip_char(tport, 0, TTY_BREAK)) 812 copied++; 813 } 814 815 } else { 816 /* frame error */ 817 port->icount.frame++; 818 819 if (tty_insert_flip_char(tport, 0, TTY_FRAME)) 820 copied++; 821 822 dev_notice(port->dev, "frame error\n"); 823 } 824 } 825 826 if (status & SCxSR_PER(port)) { 827 /* parity error */ 828 port->icount.parity++; 829 830 if (tty_insert_flip_char(tport, 0, TTY_PARITY)) 831 copied++; 832 833 dev_notice(port->dev, "parity error\n"); 834 } 835 836 if (copied) 837 tty_flip_buffer_push(tport); 838 839 return copied; 840 } 841 842 static int sci_handle_fifo_overrun(struct uart_port *port) 843 { 844 struct tty_port *tport = &port->state->port; 845 struct sci_port *s = to_sci_port(port); 846 struct plat_sci_reg *reg; 847 int copied = 0; 848 849 reg = sci_getreg(port, SCLSR); 850 if (!reg->size) 851 return 0; 852 853 if ((serial_port_in(port, SCLSR) & (1 << s->overrun_bit))) { 854 serial_port_out(port, SCLSR, 0); 855 856 port->icount.overrun++; 857 858 tty_insert_flip_char(tport, 0, TTY_OVERRUN); 859 tty_flip_buffer_push(tport); 860 861 dev_notice(port->dev, "overrun error\n"); 862 copied++; 863 } 864 865 return copied; 866 } 867 868 static int sci_handle_breaks(struct uart_port *port) 869 { 870 int copied = 0; 871 unsigned short status = serial_port_in(port, SCxSR); 872 struct tty_port *tport = &port->state->port; 873 struct sci_port *s = to_sci_port(port); 874 875 if (uart_handle_break(port)) 876 return 0; 877 878 if (!s->break_flag && status & SCxSR_BRK(port)) { 879 #if defined(CONFIG_CPU_SH3) 880 /* Debounce break */ 881 s->break_flag = 1; 882 #endif 883 884 port->icount.brk++; 885 886 /* Notify of BREAK */ 887 if (tty_insert_flip_char(tport, 0, TTY_BREAK)) 888 copied++; 889 890 dev_dbg(port->dev, "BREAK detected\n"); 891 } 892 893 if (copied) 894 tty_flip_buffer_push(tport); 895 896 copied += sci_handle_fifo_overrun(port); 897 898 return copied; 899 } 900 901 static irqreturn_t sci_rx_interrupt(int irq, void *ptr) 902 { 903 #ifdef CONFIG_SERIAL_SH_SCI_DMA 904 struct uart_port *port = ptr; 905 struct sci_port *s = to_sci_port(port); 906 907 if (s->chan_rx) { 908 u16 scr = serial_port_in(port, SCSCR); 909 u16 ssr = serial_port_in(port, SCxSR); 910 911 /* Disable future Rx interrupts */ 912 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { 913 disable_irq_nosync(irq); 914 scr |= SCSCR_RDRQE; 915 } else { 916 scr &= ~SCSCR_RIE; 917 } 918 serial_port_out(port, SCSCR, scr); 919 /* Clear current interrupt */ 920 serial_port_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port))); 921 dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n", 922 jiffies, s->rx_timeout); 923 mod_timer(&s->rx_timer, jiffies + s->rx_timeout); 924 925 return IRQ_HANDLED; 926 } 927 #endif 928 929 /* I think sci_receive_chars has to be called irrespective 930 * of whether the I_IXOFF is set, otherwise, how is the interrupt 931 * to be disabled? 932 */ 933 sci_receive_chars(ptr); 934 935 return IRQ_HANDLED; 936 } 937 938 static irqreturn_t sci_tx_interrupt(int irq, void *ptr) 939 { 940 struct uart_port *port = ptr; 941 unsigned long flags; 942 943 spin_lock_irqsave(&port->lock, flags); 944 sci_transmit_chars(port); 945 spin_unlock_irqrestore(&port->lock, flags); 946 947 return IRQ_HANDLED; 948 } 949 950 static irqreturn_t sci_er_interrupt(int irq, void *ptr) 951 { 952 struct uart_port *port = ptr; 953 954 /* Handle errors */ 955 if (port->type == PORT_SCI) { 956 if (sci_handle_errors(port)) { 957 /* discard character in rx buffer */ 958 serial_port_in(port, SCxSR); 959 serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); 960 } 961 } else { 962 sci_handle_fifo_overrun(port); 963 sci_rx_interrupt(irq, ptr); 964 } 965 966 serial_port_out(port, SCxSR, SCxSR_ERROR_CLEAR(port)); 967 968 /* Kick the transmission */ 969 sci_tx_interrupt(irq, ptr); 970 971 return IRQ_HANDLED; 972 } 973 974 static irqreturn_t sci_br_interrupt(int irq, void *ptr) 975 { 976 struct uart_port *port = ptr; 977 978 /* Handle BREAKs */ 979 sci_handle_breaks(port); 980 serial_port_out(port, SCxSR, SCxSR_BREAK_CLEAR(port)); 981 982 return IRQ_HANDLED; 983 } 984 985 static inline unsigned long port_rx_irq_mask(struct uart_port *port) 986 { 987 /* 988 * Not all ports (such as SCIFA) will support REIE. Rather than 989 * special-casing the port type, we check the port initialization 990 * IRQ enable mask to see whether the IRQ is desired at all. If 991 * it's unset, it's logically inferred that there's no point in 992 * testing for it. 993 */ 994 return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE); 995 } 996 997 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) 998 { 999 unsigned short ssr_status, scr_status, err_enabled; 1000 struct uart_port *port = ptr; 1001 struct sci_port *s = to_sci_port(port); 1002 irqreturn_t ret = IRQ_NONE; 1003 1004 ssr_status = serial_port_in(port, SCxSR); 1005 scr_status = serial_port_in(port, SCSCR); 1006 err_enabled = scr_status & port_rx_irq_mask(port); 1007 1008 /* Tx Interrupt */ 1009 if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) && 1010 !s->chan_tx) 1011 ret = sci_tx_interrupt(irq, ptr); 1012 1013 /* 1014 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF / 1015 * DR flags 1016 */ 1017 if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) && 1018 (scr_status & SCSCR_RIE)) 1019 ret = sci_rx_interrupt(irq, ptr); 1020 1021 /* Error Interrupt */ 1022 if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled) 1023 ret = sci_er_interrupt(irq, ptr); 1024 1025 /* Break Interrupt */ 1026 if ((ssr_status & SCxSR_BRK(port)) && err_enabled) 1027 ret = sci_br_interrupt(irq, ptr); 1028 1029 return ret; 1030 } 1031 1032 /* 1033 * Here we define a transition notifier so that we can update all of our 1034 * ports' baud rate when the peripheral clock changes. 1035 */ 1036 static int sci_notifier(struct notifier_block *self, 1037 unsigned long phase, void *p) 1038 { 1039 struct sci_port *sci_port; 1040 unsigned long flags; 1041 1042 sci_port = container_of(self, struct sci_port, freq_transition); 1043 1044 if (phase == CPUFREQ_POSTCHANGE) { 1045 struct uart_port *port = &sci_port->port; 1046 1047 spin_lock_irqsave(&port->lock, flags); 1048 port->uartclk = clk_get_rate(sci_port->iclk); 1049 spin_unlock_irqrestore(&port->lock, flags); 1050 } 1051 1052 return NOTIFY_OK; 1053 } 1054 1055 static struct sci_irq_desc { 1056 const char *desc; 1057 irq_handler_t handler; 1058 } sci_irq_desc[] = { 1059 /* 1060 * Split out handlers, the default case. 1061 */ 1062 [SCIx_ERI_IRQ] = { 1063 .desc = "rx err", 1064 .handler = sci_er_interrupt, 1065 }, 1066 1067 [SCIx_RXI_IRQ] = { 1068 .desc = "rx full", 1069 .handler = sci_rx_interrupt, 1070 }, 1071 1072 [SCIx_TXI_IRQ] = { 1073 .desc = "tx empty", 1074 .handler = sci_tx_interrupt, 1075 }, 1076 1077 [SCIx_BRI_IRQ] = { 1078 .desc = "break", 1079 .handler = sci_br_interrupt, 1080 }, 1081 1082 /* 1083 * Special muxed handler. 1084 */ 1085 [SCIx_MUX_IRQ] = { 1086 .desc = "mux", 1087 .handler = sci_mpxed_interrupt, 1088 }, 1089 }; 1090 1091 static int sci_request_irq(struct sci_port *port) 1092 { 1093 struct uart_port *up = &port->port; 1094 int i, j, ret = 0; 1095 1096 for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) { 1097 struct sci_irq_desc *desc; 1098 int irq; 1099 1100 if (SCIx_IRQ_IS_MUXED(port)) { 1101 i = SCIx_MUX_IRQ; 1102 irq = up->irq; 1103 } else { 1104 irq = port->irqs[i]; 1105 1106 /* 1107 * Certain port types won't support all of the 1108 * available interrupt sources. 1109 */ 1110 if (unlikely(irq < 0)) 1111 continue; 1112 } 1113 1114 desc = sci_irq_desc + i; 1115 port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s", 1116 dev_name(up->dev), desc->desc); 1117 if (!port->irqstr[j]) { 1118 dev_err(up->dev, "Failed to allocate %s IRQ string\n", 1119 desc->desc); 1120 goto out_nomem; 1121 } 1122 1123 ret = request_irq(irq, desc->handler, up->irqflags, 1124 port->irqstr[j], port); 1125 if (unlikely(ret)) { 1126 dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc); 1127 goto out_noirq; 1128 } 1129 } 1130 1131 return 0; 1132 1133 out_noirq: 1134 while (--i >= 0) 1135 free_irq(port->irqs[i], port); 1136 1137 out_nomem: 1138 while (--j >= 0) 1139 kfree(port->irqstr[j]); 1140 1141 return ret; 1142 } 1143 1144 static void sci_free_irq(struct sci_port *port) 1145 { 1146 int i; 1147 1148 /* 1149 * Intentionally in reverse order so we iterate over the muxed 1150 * IRQ first. 1151 */ 1152 for (i = 0; i < SCIx_NR_IRQS; i++) { 1153 int irq = port->irqs[i]; 1154 1155 /* 1156 * Certain port types won't support all of the available 1157 * interrupt sources. 1158 */ 1159 if (unlikely(irq < 0)) 1160 continue; 1161 1162 free_irq(port->irqs[i], port); 1163 kfree(port->irqstr[i]); 1164 1165 if (SCIx_IRQ_IS_MUXED(port)) { 1166 /* If there's only one IRQ, we're done. */ 1167 return; 1168 } 1169 } 1170 } 1171 1172 static unsigned int sci_tx_empty(struct uart_port *port) 1173 { 1174 unsigned short status = serial_port_in(port, SCxSR); 1175 unsigned short in_tx_fifo = sci_txfill(port); 1176 1177 return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0; 1178 } 1179 1180 /* 1181 * Modem control is a bit of a mixed bag for SCI(F) ports. Generally 1182 * CTS/RTS is supported in hardware by at least one port and controlled 1183 * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently 1184 * handled via the ->init_pins() op, which is a bit of a one-way street, 1185 * lacking any ability to defer pin control -- this will later be 1186 * converted over to the GPIO framework). 1187 * 1188 * Other modes (such as loopback) are supported generically on certain 1189 * port types, but not others. For these it's sufficient to test for the 1190 * existence of the support register and simply ignore the port type. 1191 */ 1192 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl) 1193 { 1194 if (mctrl & TIOCM_LOOP) { 1195 struct plat_sci_reg *reg; 1196 1197 /* 1198 * Standard loopback mode for SCFCR ports. 1199 */ 1200 reg = sci_getreg(port, SCFCR); 1201 if (reg->size) 1202 serial_port_out(port, SCFCR, 1203 serial_port_in(port, SCFCR) | 1204 SCFCR_LOOP); 1205 } 1206 } 1207 1208 static unsigned int sci_get_mctrl(struct uart_port *port) 1209 { 1210 /* 1211 * CTS/RTS is handled in hardware when supported, while nothing 1212 * else is wired up. Keep it simple and simply assert DSR/CAR. 1213 */ 1214 return TIOCM_DSR | TIOCM_CAR; 1215 } 1216 1217 #ifdef CONFIG_SERIAL_SH_SCI_DMA 1218 static void sci_dma_tx_complete(void *arg) 1219 { 1220 struct sci_port *s = arg; 1221 struct uart_port *port = &s->port; 1222 struct circ_buf *xmit = &port->state->xmit; 1223 unsigned long flags; 1224 1225 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); 1226 1227 spin_lock_irqsave(&port->lock, flags); 1228 1229 xmit->tail += sg_dma_len(&s->sg_tx); 1230 xmit->tail &= UART_XMIT_SIZE - 1; 1231 1232 port->icount.tx += sg_dma_len(&s->sg_tx); 1233 1234 async_tx_ack(s->desc_tx); 1235 s->desc_tx = NULL; 1236 1237 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 1238 uart_write_wakeup(port); 1239 1240 if (!uart_circ_empty(xmit)) { 1241 s->cookie_tx = 0; 1242 schedule_work(&s->work_tx); 1243 } else { 1244 s->cookie_tx = -EINVAL; 1245 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { 1246 u16 ctrl = serial_port_in(port, SCSCR); 1247 serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE); 1248 } 1249 } 1250 1251 spin_unlock_irqrestore(&port->lock, flags); 1252 } 1253 1254 /* Locking: called with port lock held */ 1255 static int sci_dma_rx_push(struct sci_port *s, size_t count) 1256 { 1257 struct uart_port *port = &s->port; 1258 struct tty_port *tport = &port->state->port; 1259 int i, active, room; 1260 1261 room = tty_buffer_request_room(tport, count); 1262 1263 if (s->active_rx == s->cookie_rx[0]) { 1264 active = 0; 1265 } else if (s->active_rx == s->cookie_rx[1]) { 1266 active = 1; 1267 } else { 1268 dev_err(port->dev, "cookie %d not found!\n", s->active_rx); 1269 return 0; 1270 } 1271 1272 if (room < count) 1273 dev_warn(port->dev, "Rx overrun: dropping %zu bytes\n", 1274 count - room); 1275 if (!room) 1276 return room; 1277 1278 for (i = 0; i < room; i++) 1279 tty_insert_flip_char(tport, ((u8 *)sg_virt(&s->sg_rx[active]))[i], 1280 TTY_NORMAL); 1281 1282 port->icount.rx += room; 1283 1284 return room; 1285 } 1286 1287 static void sci_dma_rx_complete(void *arg) 1288 { 1289 struct sci_port *s = arg; 1290 struct uart_port *port = &s->port; 1291 unsigned long flags; 1292 int count; 1293 1294 dev_dbg(port->dev, "%s(%d) active #%d\n", 1295 __func__, port->line, s->active_rx); 1296 1297 spin_lock_irqsave(&port->lock, flags); 1298 1299 count = sci_dma_rx_push(s, s->buf_len_rx); 1300 1301 mod_timer(&s->rx_timer, jiffies + s->rx_timeout); 1302 1303 spin_unlock_irqrestore(&port->lock, flags); 1304 1305 if (count) 1306 tty_flip_buffer_push(&port->state->port); 1307 1308 schedule_work(&s->work_rx); 1309 } 1310 1311 static void sci_rx_dma_release(struct sci_port *s, bool enable_pio) 1312 { 1313 struct dma_chan *chan = s->chan_rx; 1314 struct uart_port *port = &s->port; 1315 1316 s->chan_rx = NULL; 1317 s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL; 1318 dma_release_channel(chan); 1319 if (sg_dma_address(&s->sg_rx[0])) 1320 dma_free_coherent(port->dev, s->buf_len_rx * 2, 1321 sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0])); 1322 if (enable_pio) 1323 sci_start_rx(port); 1324 } 1325 1326 static void sci_tx_dma_release(struct sci_port *s, bool enable_pio) 1327 { 1328 struct dma_chan *chan = s->chan_tx; 1329 struct uart_port *port = &s->port; 1330 1331 s->chan_tx = NULL; 1332 s->cookie_tx = -EINVAL; 1333 dma_release_channel(chan); 1334 if (enable_pio) 1335 sci_start_tx(port); 1336 } 1337 1338 static void sci_submit_rx(struct sci_port *s) 1339 { 1340 struct dma_chan *chan = s->chan_rx; 1341 int i; 1342 1343 for (i = 0; i < 2; i++) { 1344 struct scatterlist *sg = &s->sg_rx[i]; 1345 struct dma_async_tx_descriptor *desc; 1346 1347 desc = dmaengine_prep_slave_sg(chan, 1348 sg, 1, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); 1349 1350 if (desc) { 1351 s->desc_rx[i] = desc; 1352 desc->callback = sci_dma_rx_complete; 1353 desc->callback_param = s; 1354 s->cookie_rx[i] = desc->tx_submit(desc); 1355 } 1356 1357 if (!desc || s->cookie_rx[i] < 0) { 1358 if (i) { 1359 async_tx_ack(s->desc_rx[0]); 1360 s->cookie_rx[0] = -EINVAL; 1361 } 1362 if (desc) { 1363 async_tx_ack(desc); 1364 s->cookie_rx[i] = -EINVAL; 1365 } 1366 dev_warn(s->port.dev, 1367 "failed to re-start DMA, using PIO\n"); 1368 sci_rx_dma_release(s, true); 1369 return; 1370 } 1371 dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", 1372 __func__, s->cookie_rx[i], i); 1373 } 1374 1375 s->active_rx = s->cookie_rx[0]; 1376 1377 dma_async_issue_pending(chan); 1378 } 1379 1380 static void work_fn_rx(struct work_struct *work) 1381 { 1382 struct sci_port *s = container_of(work, struct sci_port, work_rx); 1383 struct uart_port *port = &s->port; 1384 struct dma_async_tx_descriptor *desc; 1385 int new; 1386 1387 if (s->active_rx == s->cookie_rx[0]) { 1388 new = 0; 1389 } else if (s->active_rx == s->cookie_rx[1]) { 1390 new = 1; 1391 } else { 1392 dev_err(port->dev, "cookie %d not found!\n", s->active_rx); 1393 return; 1394 } 1395 desc = s->desc_rx[new]; 1396 1397 if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) != 1398 DMA_COMPLETE) { 1399 /* Handle incomplete DMA receive */ 1400 struct dma_chan *chan = s->chan_rx; 1401 struct shdma_desc *sh_desc = container_of(desc, 1402 struct shdma_desc, async_tx); 1403 unsigned long flags; 1404 int count; 1405 1406 chan->device->device_control(chan, DMA_TERMINATE_ALL, 0); 1407 dev_dbg(port->dev, "Read %zu bytes with cookie %d\n", 1408 sh_desc->partial, sh_desc->cookie); 1409 1410 spin_lock_irqsave(&port->lock, flags); 1411 count = sci_dma_rx_push(s, sh_desc->partial); 1412 spin_unlock_irqrestore(&port->lock, flags); 1413 1414 if (count) 1415 tty_flip_buffer_push(&port->state->port); 1416 1417 sci_submit_rx(s); 1418 1419 return; 1420 } 1421 1422 s->cookie_rx[new] = desc->tx_submit(desc); 1423 if (s->cookie_rx[new] < 0) { 1424 dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n"); 1425 sci_rx_dma_release(s, true); 1426 return; 1427 } 1428 1429 s->active_rx = s->cookie_rx[!new]; 1430 1431 dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", 1432 __func__, s->cookie_rx[new], new, s->active_rx); 1433 } 1434 1435 static void work_fn_tx(struct work_struct *work) 1436 { 1437 struct sci_port *s = container_of(work, struct sci_port, work_tx); 1438 struct dma_async_tx_descriptor *desc; 1439 struct dma_chan *chan = s->chan_tx; 1440 struct uart_port *port = &s->port; 1441 struct circ_buf *xmit = &port->state->xmit; 1442 struct scatterlist *sg = &s->sg_tx; 1443 1444 /* 1445 * DMA is idle now. 1446 * Port xmit buffer is already mapped, and it is one page... Just adjust 1447 * offsets and lengths. Since it is a circular buffer, we have to 1448 * transmit till the end, and then the rest. Take the port lock to get a 1449 * consistent xmit buffer state. 1450 */ 1451 spin_lock_irq(&port->lock); 1452 sg->offset = xmit->tail & (UART_XMIT_SIZE - 1); 1453 sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) + 1454 sg->offset; 1455 sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE), 1456 CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE)); 1457 spin_unlock_irq(&port->lock); 1458 1459 BUG_ON(!sg_dma_len(sg)); 1460 1461 desc = dmaengine_prep_slave_sg(chan, 1462 sg, s->sg_len_tx, DMA_MEM_TO_DEV, 1463 DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 1464 if (!desc) { 1465 /* switch to PIO */ 1466 sci_tx_dma_release(s, true); 1467 return; 1468 } 1469 1470 dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE); 1471 1472 spin_lock_irq(&port->lock); 1473 s->desc_tx = desc; 1474 desc->callback = sci_dma_tx_complete; 1475 desc->callback_param = s; 1476 spin_unlock_irq(&port->lock); 1477 s->cookie_tx = desc->tx_submit(desc); 1478 if (s->cookie_tx < 0) { 1479 dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n"); 1480 /* switch to PIO */ 1481 sci_tx_dma_release(s, true); 1482 return; 1483 } 1484 1485 dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", 1486 __func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx); 1487 1488 dma_async_issue_pending(chan); 1489 } 1490 #endif 1491 1492 static void sci_start_tx(struct uart_port *port) 1493 { 1494 struct sci_port *s = to_sci_port(port); 1495 unsigned short ctrl; 1496 1497 #ifdef CONFIG_SERIAL_SH_SCI_DMA 1498 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { 1499 u16 new, scr = serial_port_in(port, SCSCR); 1500 if (s->chan_tx) 1501 new = scr | SCSCR_TDRQE; 1502 else 1503 new = scr & ~SCSCR_TDRQE; 1504 if (new != scr) 1505 serial_port_out(port, SCSCR, new); 1506 } 1507 1508 if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) && 1509 s->cookie_tx < 0) { 1510 s->cookie_tx = 0; 1511 schedule_work(&s->work_tx); 1512 } 1513 #endif 1514 1515 if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) { 1516 /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */ 1517 ctrl = serial_port_in(port, SCSCR); 1518 serial_port_out(port, SCSCR, ctrl | SCSCR_TIE); 1519 } 1520 } 1521 1522 static void sci_stop_tx(struct uart_port *port) 1523 { 1524 unsigned short ctrl; 1525 1526 /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */ 1527 ctrl = serial_port_in(port, SCSCR); 1528 1529 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) 1530 ctrl &= ~SCSCR_TDRQE; 1531 1532 ctrl &= ~SCSCR_TIE; 1533 1534 serial_port_out(port, SCSCR, ctrl); 1535 } 1536 1537 static void sci_start_rx(struct uart_port *port) 1538 { 1539 unsigned short ctrl; 1540 1541 ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port); 1542 1543 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) 1544 ctrl &= ~SCSCR_RDRQE; 1545 1546 serial_port_out(port, SCSCR, ctrl); 1547 } 1548 1549 static void sci_stop_rx(struct uart_port *port) 1550 { 1551 unsigned short ctrl; 1552 1553 ctrl = serial_port_in(port, SCSCR); 1554 1555 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) 1556 ctrl &= ~SCSCR_RDRQE; 1557 1558 ctrl &= ~port_rx_irq_mask(port); 1559 1560 serial_port_out(port, SCSCR, ctrl); 1561 } 1562 1563 static void sci_enable_ms(struct uart_port *port) 1564 { 1565 /* 1566 * Not supported by hardware, always a nop. 1567 */ 1568 } 1569 1570 static void sci_break_ctl(struct uart_port *port, int break_state) 1571 { 1572 struct sci_port *s = to_sci_port(port); 1573 struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR; 1574 unsigned short scscr, scsptr; 1575 1576 /* check wheter the port has SCSPTR */ 1577 if (!reg->size) { 1578 /* 1579 * Not supported by hardware. Most parts couple break and rx 1580 * interrupts together, with break detection always enabled. 1581 */ 1582 return; 1583 } 1584 1585 scsptr = serial_port_in(port, SCSPTR); 1586 scscr = serial_port_in(port, SCSCR); 1587 1588 if (break_state == -1) { 1589 scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT; 1590 scscr &= ~SCSCR_TE; 1591 } else { 1592 scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO; 1593 scscr |= SCSCR_TE; 1594 } 1595 1596 serial_port_out(port, SCSPTR, scsptr); 1597 serial_port_out(port, SCSCR, scscr); 1598 } 1599 1600 #ifdef CONFIG_SERIAL_SH_SCI_DMA 1601 static bool filter(struct dma_chan *chan, void *slave) 1602 { 1603 struct sh_dmae_slave *param = slave; 1604 1605 dev_dbg(chan->device->dev, "%s: slave ID %d\n", 1606 __func__, param->shdma_slave.slave_id); 1607 1608 chan->private = ¶m->shdma_slave; 1609 return true; 1610 } 1611 1612 static void rx_timer_fn(unsigned long arg) 1613 { 1614 struct sci_port *s = (struct sci_port *)arg; 1615 struct uart_port *port = &s->port; 1616 u16 scr = serial_port_in(port, SCSCR); 1617 1618 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { 1619 scr &= ~SCSCR_RDRQE; 1620 enable_irq(s->irqs[SCIx_RXI_IRQ]); 1621 } 1622 serial_port_out(port, SCSCR, scr | SCSCR_RIE); 1623 dev_dbg(port->dev, "DMA Rx timed out\n"); 1624 schedule_work(&s->work_rx); 1625 } 1626 1627 static void sci_request_dma(struct uart_port *port) 1628 { 1629 struct sci_port *s = to_sci_port(port); 1630 struct sh_dmae_slave *param; 1631 struct dma_chan *chan; 1632 dma_cap_mask_t mask; 1633 int nent; 1634 1635 dev_dbg(port->dev, "%s: port %d\n", __func__, port->line); 1636 1637 if (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0) 1638 return; 1639 1640 dma_cap_zero(mask); 1641 dma_cap_set(DMA_SLAVE, mask); 1642 1643 param = &s->param_tx; 1644 1645 /* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */ 1646 param->shdma_slave.slave_id = s->cfg->dma_slave_tx; 1647 1648 s->cookie_tx = -EINVAL; 1649 chan = dma_request_channel(mask, filter, param); 1650 dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan); 1651 if (chan) { 1652 s->chan_tx = chan; 1653 sg_init_table(&s->sg_tx, 1); 1654 /* UART circular tx buffer is an aligned page. */ 1655 BUG_ON((uintptr_t)port->state->xmit.buf & ~PAGE_MASK); 1656 sg_set_page(&s->sg_tx, virt_to_page(port->state->xmit.buf), 1657 UART_XMIT_SIZE, 1658 (uintptr_t)port->state->xmit.buf & ~PAGE_MASK); 1659 nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE); 1660 if (!nent) 1661 sci_tx_dma_release(s, false); 1662 else 1663 dev_dbg(port->dev, "%s: mapped %d@%p to %pad\n", 1664 __func__, 1665 sg_dma_len(&s->sg_tx), port->state->xmit.buf, 1666 &sg_dma_address(&s->sg_tx)); 1667 1668 s->sg_len_tx = nent; 1669 1670 INIT_WORK(&s->work_tx, work_fn_tx); 1671 } 1672 1673 param = &s->param_rx; 1674 1675 /* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */ 1676 param->shdma_slave.slave_id = s->cfg->dma_slave_rx; 1677 1678 chan = dma_request_channel(mask, filter, param); 1679 dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan); 1680 if (chan) { 1681 dma_addr_t dma[2]; 1682 void *buf[2]; 1683 int i; 1684 1685 s->chan_rx = chan; 1686 1687 s->buf_len_rx = 2 * max(16, (int)port->fifosize); 1688 buf[0] = dma_alloc_coherent(port->dev, s->buf_len_rx * 2, 1689 &dma[0], GFP_KERNEL); 1690 1691 if (!buf[0]) { 1692 dev_warn(port->dev, 1693 "failed to allocate dma buffer, using PIO\n"); 1694 sci_rx_dma_release(s, true); 1695 return; 1696 } 1697 1698 buf[1] = buf[0] + s->buf_len_rx; 1699 dma[1] = dma[0] + s->buf_len_rx; 1700 1701 for (i = 0; i < 2; i++) { 1702 struct scatterlist *sg = &s->sg_rx[i]; 1703 1704 sg_init_table(sg, 1); 1705 sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx, 1706 (uintptr_t)buf[i] & ~PAGE_MASK); 1707 sg_dma_address(sg) = dma[i]; 1708 } 1709 1710 INIT_WORK(&s->work_rx, work_fn_rx); 1711 setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s); 1712 1713 sci_submit_rx(s); 1714 } 1715 } 1716 1717 static void sci_free_dma(struct uart_port *port) 1718 { 1719 struct sci_port *s = to_sci_port(port); 1720 1721 if (s->chan_tx) 1722 sci_tx_dma_release(s, false); 1723 if (s->chan_rx) 1724 sci_rx_dma_release(s, false); 1725 } 1726 #else 1727 static inline void sci_request_dma(struct uart_port *port) 1728 { 1729 } 1730 1731 static inline void sci_free_dma(struct uart_port *port) 1732 { 1733 } 1734 #endif 1735 1736 static int sci_startup(struct uart_port *port) 1737 { 1738 struct sci_port *s = to_sci_port(port); 1739 unsigned long flags; 1740 int ret; 1741 1742 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); 1743 1744 ret = sci_request_irq(s); 1745 if (unlikely(ret < 0)) 1746 return ret; 1747 1748 sci_request_dma(port); 1749 1750 spin_lock_irqsave(&port->lock, flags); 1751 sci_start_tx(port); 1752 sci_start_rx(port); 1753 spin_unlock_irqrestore(&port->lock, flags); 1754 1755 return 0; 1756 } 1757 1758 static void sci_shutdown(struct uart_port *port) 1759 { 1760 struct sci_port *s = to_sci_port(port); 1761 unsigned long flags; 1762 1763 dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); 1764 1765 spin_lock_irqsave(&port->lock, flags); 1766 sci_stop_rx(port); 1767 sci_stop_tx(port); 1768 spin_unlock_irqrestore(&port->lock, flags); 1769 1770 sci_free_dma(port); 1771 sci_free_irq(s); 1772 } 1773 1774 static unsigned int sci_scbrr_calc(struct sci_port *s, unsigned int bps, 1775 unsigned long freq) 1776 { 1777 if (s->sampling_rate) 1778 return DIV_ROUND_CLOSEST(freq, s->sampling_rate * bps) - 1; 1779 1780 /* Warn, but use a safe default */ 1781 WARN_ON(1); 1782 1783 return ((freq + 16 * bps) / (32 * bps) - 1); 1784 } 1785 1786 /* calculate sample rate, BRR, and clock select for HSCIF */ 1787 static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, 1788 int *brr, unsigned int *srr, 1789 unsigned int *cks) 1790 { 1791 int sr, c, br, err; 1792 int min_err = 1000; /* 100% */ 1793 1794 /* Find the combination of sample rate and clock select with the 1795 smallest deviation from the desired baud rate. */ 1796 for (sr = 8; sr <= 32; sr++) { 1797 for (c = 0; c <= 3; c++) { 1798 /* integerized formulas from HSCIF documentation */ 1799 br = freq / (sr * (1 << (2 * c + 1)) * bps) - 1; 1800 if (br < 0 || br > 255) 1801 continue; 1802 err = freq / ((br + 1) * bps * sr * 1803 (1 << (2 * c + 1)) / 1000) - 1000; 1804 if (min_err > err) { 1805 min_err = err; 1806 *brr = br; 1807 *srr = sr - 1; 1808 *cks = c; 1809 } 1810 } 1811 } 1812 1813 if (min_err == 1000) { 1814 WARN_ON(1); 1815 /* use defaults */ 1816 *brr = 255; 1817 *srr = 15; 1818 *cks = 0; 1819 } 1820 } 1821 1822 static void sci_reset(struct uart_port *port) 1823 { 1824 struct plat_sci_reg *reg; 1825 unsigned int status; 1826 1827 do { 1828 status = serial_port_in(port, SCxSR); 1829 } while (!(status & SCxSR_TEND(port))); 1830 1831 serial_port_out(port, SCSCR, 0x00); /* TE=0, RE=0, CKE1=0 */ 1832 1833 reg = sci_getreg(port, SCFCR); 1834 if (reg->size) 1835 serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST); 1836 } 1837 1838 static void sci_set_termios(struct uart_port *port, struct ktermios *termios, 1839 struct ktermios *old) 1840 { 1841 struct sci_port *s = to_sci_port(port); 1842 struct plat_sci_reg *reg; 1843 unsigned int baud, smr_val, max_baud, cks = 0; 1844 int t = -1; 1845 unsigned int srr = 15; 1846 1847 /* 1848 * earlyprintk comes here early on with port->uartclk set to zero. 1849 * the clock framework is not up and running at this point so here 1850 * we assume that 115200 is the maximum baud rate. please note that 1851 * the baud rate is not programmed during earlyprintk - it is assumed 1852 * that the previous boot loader has enabled required clocks and 1853 * setup the baud rate generator hardware for us already. 1854 */ 1855 max_baud = port->uartclk ? port->uartclk / 16 : 115200; 1856 1857 baud = uart_get_baud_rate(port, termios, old, 0, max_baud); 1858 if (likely(baud && port->uartclk)) { 1859 if (s->cfg->type == PORT_HSCIF) { 1860 sci_baud_calc_hscif(baud, port->uartclk, &t, &srr, 1861 &cks); 1862 } else { 1863 t = sci_scbrr_calc(s, baud, port->uartclk); 1864 for (cks = 0; t >= 256 && cks <= 3; cks++) 1865 t >>= 2; 1866 } 1867 } 1868 1869 sci_port_enable(s); 1870 1871 sci_reset(port); 1872 1873 smr_val = serial_port_in(port, SCSMR) & 3; 1874 1875 if ((termios->c_cflag & CSIZE) == CS7) 1876 smr_val |= SCSMR_CHR; 1877 if (termios->c_cflag & PARENB) 1878 smr_val |= SCSMR_PE; 1879 if (termios->c_cflag & PARODD) 1880 smr_val |= SCSMR_PE | SCSMR_ODD; 1881 if (termios->c_cflag & CSTOPB) 1882 smr_val |= SCSMR_STOP; 1883 1884 uart_update_timeout(port, termios->c_cflag, baud); 1885 1886 dev_dbg(port->dev, "%s: SMR %x, cks %x, t %x, SCSCR %x\n", 1887 __func__, smr_val, cks, t, s->cfg->scscr); 1888 1889 if (t >= 0) { 1890 serial_port_out(port, SCSMR, (smr_val & ~SCSMR_CKS) | cks); 1891 serial_port_out(port, SCBRR, t); 1892 reg = sci_getreg(port, HSSRR); 1893 if (reg->size) 1894 serial_port_out(port, HSSRR, srr | HSCIF_SRE); 1895 udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */ 1896 } else 1897 serial_port_out(port, SCSMR, smr_val); 1898 1899 sci_init_pins(port, termios->c_cflag); 1900 1901 reg = sci_getreg(port, SCFCR); 1902 if (reg->size) { 1903 unsigned short ctrl = serial_port_in(port, SCFCR); 1904 1905 if (s->cfg->capabilities & SCIx_HAVE_RTSCTS) { 1906 if (termios->c_cflag & CRTSCTS) 1907 ctrl |= SCFCR_MCE; 1908 else 1909 ctrl &= ~SCFCR_MCE; 1910 } 1911 1912 /* 1913 * As we've done a sci_reset() above, ensure we don't 1914 * interfere with the FIFOs while toggling MCE. As the 1915 * reset values could still be set, simply mask them out. 1916 */ 1917 ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST); 1918 1919 serial_port_out(port, SCFCR, ctrl); 1920 } 1921 1922 serial_port_out(port, SCSCR, s->cfg->scscr); 1923 1924 #ifdef CONFIG_SERIAL_SH_SCI_DMA 1925 /* 1926 * Calculate delay for 1.5 DMA buffers: see 1927 * drivers/serial/serial_core.c::uart_update_timeout(). With 10 bits 1928 * (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function 1929 * calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)." 1930 * Then below we calculate 3 jiffies (12ms) for 1.5 DMA buffers (3 FIFO 1931 * sizes), but it has been found out experimentally, that this is not 1932 * enough: the driver too often needlessly runs on a DMA timeout. 20ms 1933 * as a minimum seem to work perfectly. 1934 */ 1935 if (s->chan_rx) { 1936 s->rx_timeout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 / 1937 port->fifosize / 2; 1938 dev_dbg(port->dev, "DMA Rx t-out %ums, tty t-out %u jiffies\n", 1939 s->rx_timeout * 1000 / HZ, port->timeout); 1940 if (s->rx_timeout < msecs_to_jiffies(20)) 1941 s->rx_timeout = msecs_to_jiffies(20); 1942 } 1943 #endif 1944 1945 if ((termios->c_cflag & CREAD) != 0) 1946 sci_start_rx(port); 1947 1948 sci_port_disable(s); 1949 } 1950 1951 static void sci_pm(struct uart_port *port, unsigned int state, 1952 unsigned int oldstate) 1953 { 1954 struct sci_port *sci_port = to_sci_port(port); 1955 1956 switch (state) { 1957 case UART_PM_STATE_OFF: 1958 sci_port_disable(sci_port); 1959 break; 1960 default: 1961 sci_port_enable(sci_port); 1962 break; 1963 } 1964 } 1965 1966 static const char *sci_type(struct uart_port *port) 1967 { 1968 switch (port->type) { 1969 case PORT_IRDA: 1970 return "irda"; 1971 case PORT_SCI: 1972 return "sci"; 1973 case PORT_SCIF: 1974 return "scif"; 1975 case PORT_SCIFA: 1976 return "scifa"; 1977 case PORT_SCIFB: 1978 return "scifb"; 1979 case PORT_HSCIF: 1980 return "hscif"; 1981 } 1982 1983 return NULL; 1984 } 1985 1986 static inline unsigned long sci_port_size(struct uart_port *port) 1987 { 1988 /* 1989 * Pick an arbitrary size that encapsulates all of the base 1990 * registers by default. This can be optimized later, or derived 1991 * from platform resource data at such a time that ports begin to 1992 * behave more erratically. 1993 */ 1994 if (port->type == PORT_HSCIF) 1995 return 96; 1996 else 1997 return 64; 1998 } 1999 2000 static int sci_remap_port(struct uart_port *port) 2001 { 2002 unsigned long size = sci_port_size(port); 2003 2004 /* 2005 * Nothing to do if there's already an established membase. 2006 */ 2007 if (port->membase) 2008 return 0; 2009 2010 if (port->flags & UPF_IOREMAP) { 2011 port->membase = ioremap_nocache(port->mapbase, size); 2012 if (unlikely(!port->membase)) { 2013 dev_err(port->dev, "can't remap port#%d\n", port->line); 2014 return -ENXIO; 2015 } 2016 } else { 2017 /* 2018 * For the simple (and majority of) cases where we don't 2019 * need to do any remapping, just cast the cookie 2020 * directly. 2021 */ 2022 port->membase = (void __iomem *)(uintptr_t)port->mapbase; 2023 } 2024 2025 return 0; 2026 } 2027 2028 static void sci_release_port(struct uart_port *port) 2029 { 2030 if (port->flags & UPF_IOREMAP) { 2031 iounmap(port->membase); 2032 port->membase = NULL; 2033 } 2034 2035 release_mem_region(port->mapbase, sci_port_size(port)); 2036 } 2037 2038 static int sci_request_port(struct uart_port *port) 2039 { 2040 unsigned long size = sci_port_size(port); 2041 struct resource *res; 2042 int ret; 2043 2044 res = request_mem_region(port->mapbase, size, dev_name(port->dev)); 2045 if (unlikely(res == NULL)) 2046 return -EBUSY; 2047 2048 ret = sci_remap_port(port); 2049 if (unlikely(ret != 0)) { 2050 release_resource(res); 2051 return ret; 2052 } 2053 2054 return 0; 2055 } 2056 2057 static void sci_config_port(struct uart_port *port, int flags) 2058 { 2059 if (flags & UART_CONFIG_TYPE) { 2060 struct sci_port *sport = to_sci_port(port); 2061 2062 port->type = sport->cfg->type; 2063 sci_request_port(port); 2064 } 2065 } 2066 2067 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser) 2068 { 2069 if (ser->baud_base < 2400) 2070 /* No paper tape reader for Mitch.. */ 2071 return -EINVAL; 2072 2073 return 0; 2074 } 2075 2076 static struct uart_ops sci_uart_ops = { 2077 .tx_empty = sci_tx_empty, 2078 .set_mctrl = sci_set_mctrl, 2079 .get_mctrl = sci_get_mctrl, 2080 .start_tx = sci_start_tx, 2081 .stop_tx = sci_stop_tx, 2082 .stop_rx = sci_stop_rx, 2083 .enable_ms = sci_enable_ms, 2084 .break_ctl = sci_break_ctl, 2085 .startup = sci_startup, 2086 .shutdown = sci_shutdown, 2087 .set_termios = sci_set_termios, 2088 .pm = sci_pm, 2089 .type = sci_type, 2090 .release_port = sci_release_port, 2091 .request_port = sci_request_port, 2092 .config_port = sci_config_port, 2093 .verify_port = sci_verify_port, 2094 #ifdef CONFIG_CONSOLE_POLL 2095 .poll_get_char = sci_poll_get_char, 2096 .poll_put_char = sci_poll_put_char, 2097 #endif 2098 }; 2099 2100 static int sci_init_single(struct platform_device *dev, 2101 struct sci_port *sci_port, unsigned int index, 2102 struct plat_sci_port *p, bool early) 2103 { 2104 struct uart_port *port = &sci_port->port; 2105 const struct resource *res; 2106 unsigned int sampling_rate; 2107 unsigned int i; 2108 int ret; 2109 2110 sci_port->cfg = p; 2111 2112 port->ops = &sci_uart_ops; 2113 port->iotype = UPIO_MEM; 2114 port->line = index; 2115 2116 res = platform_get_resource(dev, IORESOURCE_MEM, 0); 2117 if (res == NULL) 2118 return -ENOMEM; 2119 2120 port->mapbase = res->start; 2121 2122 for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) 2123 sci_port->irqs[i] = platform_get_irq(dev, i); 2124 2125 /* The SCI generates several interrupts. They can be muxed together or 2126 * connected to different interrupt lines. In the muxed case only one 2127 * interrupt resource is specified. In the non-muxed case three or four 2128 * interrupt resources are specified, as the BRI interrupt is optional. 2129 */ 2130 if (sci_port->irqs[0] < 0) 2131 return -ENXIO; 2132 2133 if (sci_port->irqs[1] < 0) { 2134 sci_port->irqs[1] = sci_port->irqs[0]; 2135 sci_port->irqs[2] = sci_port->irqs[0]; 2136 sci_port->irqs[3] = sci_port->irqs[0]; 2137 } 2138 2139 if (p->regtype == SCIx_PROBE_REGTYPE) { 2140 ret = sci_probe_regmap(p); 2141 if (unlikely(ret)) 2142 return ret; 2143 } 2144 2145 switch (p->type) { 2146 case PORT_SCIFB: 2147 port->fifosize = 256; 2148 sci_port->overrun_bit = 9; 2149 sampling_rate = 16; 2150 break; 2151 case PORT_HSCIF: 2152 port->fifosize = 128; 2153 sampling_rate = 0; 2154 sci_port->overrun_bit = 0; 2155 break; 2156 case PORT_SCIFA: 2157 port->fifosize = 64; 2158 sci_port->overrun_bit = 9; 2159 sampling_rate = 16; 2160 break; 2161 case PORT_SCIF: 2162 port->fifosize = 16; 2163 if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) { 2164 sci_port->overrun_bit = 9; 2165 sampling_rate = 16; 2166 } else { 2167 sci_port->overrun_bit = 0; 2168 sampling_rate = 32; 2169 } 2170 break; 2171 default: 2172 port->fifosize = 1; 2173 sci_port->overrun_bit = 5; 2174 sampling_rate = 32; 2175 break; 2176 } 2177 2178 /* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't 2179 * match the SoC datasheet, this should be investigated. Let platform 2180 * data override the sampling rate for now. 2181 */ 2182 sci_port->sampling_rate = p->sampling_rate ? p->sampling_rate 2183 : sampling_rate; 2184 2185 if (!early) { 2186 sci_port->iclk = clk_get(&dev->dev, "sci_ick"); 2187 if (IS_ERR(sci_port->iclk)) { 2188 sci_port->iclk = clk_get(&dev->dev, "peripheral_clk"); 2189 if (IS_ERR(sci_port->iclk)) { 2190 dev_err(&dev->dev, "can't get iclk\n"); 2191 return PTR_ERR(sci_port->iclk); 2192 } 2193 } 2194 2195 /* 2196 * The function clock is optional, ignore it if we can't 2197 * find it. 2198 */ 2199 sci_port->fclk = clk_get(&dev->dev, "sci_fck"); 2200 if (IS_ERR(sci_port->fclk)) 2201 sci_port->fclk = NULL; 2202 2203 port->dev = &dev->dev; 2204 2205 pm_runtime_enable(&dev->dev); 2206 } 2207 2208 sci_port->break_timer.data = (unsigned long)sci_port; 2209 sci_port->break_timer.function = sci_break_timer; 2210 init_timer(&sci_port->break_timer); 2211 2212 /* 2213 * Establish some sensible defaults for the error detection. 2214 */ 2215 sci_port->error_mask = (p->type == PORT_SCI) ? 2216 SCI_DEFAULT_ERROR_MASK : SCIF_DEFAULT_ERROR_MASK; 2217 2218 /* 2219 * Establish sensible defaults for the overrun detection, unless 2220 * the part has explicitly disabled support for it. 2221 */ 2222 2223 /* 2224 * Make the error mask inclusive of overrun detection, if 2225 * supported. 2226 */ 2227 sci_port->error_mask |= 1 << sci_port->overrun_bit; 2228 2229 port->type = p->type; 2230 port->flags = UPF_FIXED_PORT | p->flags; 2231 port->regshift = p->regshift; 2232 2233 /* 2234 * The UART port needs an IRQ value, so we peg this to the RX IRQ 2235 * for the multi-IRQ ports, which is where we are primarily 2236 * concerned with the shutdown path synchronization. 2237 * 2238 * For the muxed case there's nothing more to do. 2239 */ 2240 port->irq = sci_port->irqs[SCIx_RXI_IRQ]; 2241 port->irqflags = 0; 2242 2243 port->serial_in = sci_serial_in; 2244 port->serial_out = sci_serial_out; 2245 2246 if (p->dma_slave_tx > 0 && p->dma_slave_rx > 0) 2247 dev_dbg(port->dev, "DMA tx %d, rx %d\n", 2248 p->dma_slave_tx, p->dma_slave_rx); 2249 2250 return 0; 2251 } 2252 2253 static void sci_cleanup_single(struct sci_port *port) 2254 { 2255 clk_put(port->iclk); 2256 clk_put(port->fclk); 2257 2258 pm_runtime_disable(port->port.dev); 2259 } 2260 2261 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE 2262 static void serial_console_putchar(struct uart_port *port, int ch) 2263 { 2264 sci_poll_put_char(port, ch); 2265 } 2266 2267 /* 2268 * Print a string to the serial port trying not to disturb 2269 * any possible real use of the port... 2270 */ 2271 static void serial_console_write(struct console *co, const char *s, 2272 unsigned count) 2273 { 2274 struct sci_port *sci_port = &sci_ports[co->index]; 2275 struct uart_port *port = &sci_port->port; 2276 unsigned short bits, ctrl; 2277 unsigned long flags; 2278 int locked = 1; 2279 2280 local_irq_save(flags); 2281 if (port->sysrq) 2282 locked = 0; 2283 else if (oops_in_progress) 2284 locked = spin_trylock(&port->lock); 2285 else 2286 spin_lock(&port->lock); 2287 2288 /* first save the SCSCR then disable the interrupts */ 2289 ctrl = serial_port_in(port, SCSCR); 2290 serial_port_out(port, SCSCR, sci_port->cfg->scscr); 2291 2292 uart_console_write(port, s, count, serial_console_putchar); 2293 2294 /* wait until fifo is empty and last bit has been transmitted */ 2295 bits = SCxSR_TDxE(port) | SCxSR_TEND(port); 2296 while ((serial_port_in(port, SCxSR) & bits) != bits) 2297 cpu_relax(); 2298 2299 /* restore the SCSCR */ 2300 serial_port_out(port, SCSCR, ctrl); 2301 2302 if (locked) 2303 spin_unlock(&port->lock); 2304 local_irq_restore(flags); 2305 } 2306 2307 static int serial_console_setup(struct console *co, char *options) 2308 { 2309 struct sci_port *sci_port; 2310 struct uart_port *port; 2311 int baud = 115200; 2312 int bits = 8; 2313 int parity = 'n'; 2314 int flow = 'n'; 2315 int ret; 2316 2317 /* 2318 * Refuse to handle any bogus ports. 2319 */ 2320 if (co->index < 0 || co->index >= SCI_NPORTS) 2321 return -ENODEV; 2322 2323 sci_port = &sci_ports[co->index]; 2324 port = &sci_port->port; 2325 2326 /* 2327 * Refuse to handle uninitialized ports. 2328 */ 2329 if (!port->ops) 2330 return -ENODEV; 2331 2332 ret = sci_remap_port(port); 2333 if (unlikely(ret != 0)) 2334 return ret; 2335 2336 if (options) 2337 uart_parse_options(options, &baud, &parity, &bits, &flow); 2338 2339 return uart_set_options(port, co, baud, parity, bits, flow); 2340 } 2341 2342 static struct console serial_console = { 2343 .name = "ttySC", 2344 .device = uart_console_device, 2345 .write = serial_console_write, 2346 .setup = serial_console_setup, 2347 .flags = CON_PRINTBUFFER, 2348 .index = -1, 2349 .data = &sci_uart_driver, 2350 }; 2351 2352 static struct console early_serial_console = { 2353 .name = "early_ttySC", 2354 .write = serial_console_write, 2355 .flags = CON_PRINTBUFFER, 2356 .index = -1, 2357 }; 2358 2359 static char early_serial_buf[32]; 2360 2361 static int sci_probe_earlyprintk(struct platform_device *pdev) 2362 { 2363 struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev); 2364 2365 if (early_serial_console.data) 2366 return -EEXIST; 2367 2368 early_serial_console.index = pdev->id; 2369 2370 sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true); 2371 2372 serial_console_setup(&early_serial_console, early_serial_buf); 2373 2374 if (!strstr(early_serial_buf, "keep")) 2375 early_serial_console.flags |= CON_BOOT; 2376 2377 register_console(&early_serial_console); 2378 return 0; 2379 } 2380 2381 #define SCI_CONSOLE (&serial_console) 2382 2383 #else 2384 static inline int sci_probe_earlyprintk(struct platform_device *pdev) 2385 { 2386 return -EINVAL; 2387 } 2388 2389 #define SCI_CONSOLE NULL 2390 2391 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */ 2392 2393 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized"; 2394 2395 static struct uart_driver sci_uart_driver = { 2396 .owner = THIS_MODULE, 2397 .driver_name = "sci", 2398 .dev_name = "ttySC", 2399 .major = SCI_MAJOR, 2400 .minor = SCI_MINOR_START, 2401 .nr = SCI_NPORTS, 2402 .cons = SCI_CONSOLE, 2403 }; 2404 2405 static int sci_remove(struct platform_device *dev) 2406 { 2407 struct sci_port *port = platform_get_drvdata(dev); 2408 2409 cpufreq_unregister_notifier(&port->freq_transition, 2410 CPUFREQ_TRANSITION_NOTIFIER); 2411 2412 uart_remove_one_port(&sci_uart_driver, &port->port); 2413 2414 sci_cleanup_single(port); 2415 2416 return 0; 2417 } 2418 2419 struct sci_port_info { 2420 unsigned int type; 2421 unsigned int regtype; 2422 }; 2423 2424 static const struct of_device_id of_sci_match[] = { 2425 { 2426 .compatible = "renesas,scif", 2427 .data = &(const struct sci_port_info) { 2428 .type = PORT_SCIF, 2429 .regtype = SCIx_SH4_SCIF_REGTYPE, 2430 }, 2431 }, { 2432 .compatible = "renesas,scifa", 2433 .data = &(const struct sci_port_info) { 2434 .type = PORT_SCIFA, 2435 .regtype = SCIx_SCIFA_REGTYPE, 2436 }, 2437 }, { 2438 .compatible = "renesas,scifb", 2439 .data = &(const struct sci_port_info) { 2440 .type = PORT_SCIFB, 2441 .regtype = SCIx_SCIFB_REGTYPE, 2442 }, 2443 }, { 2444 .compatible = "renesas,hscif", 2445 .data = &(const struct sci_port_info) { 2446 .type = PORT_HSCIF, 2447 .regtype = SCIx_HSCIF_REGTYPE, 2448 }, 2449 }, { 2450 /* Terminator */ 2451 }, 2452 }; 2453 MODULE_DEVICE_TABLE(of, of_sci_match); 2454 2455 static struct plat_sci_port * 2456 sci_parse_dt(struct platform_device *pdev, unsigned int *dev_id) 2457 { 2458 struct device_node *np = pdev->dev.of_node; 2459 const struct of_device_id *match; 2460 const struct sci_port_info *info; 2461 struct plat_sci_port *p; 2462 int id; 2463 2464 if (!IS_ENABLED(CONFIG_OF) || !np) 2465 return NULL; 2466 2467 match = of_match_node(of_sci_match, pdev->dev.of_node); 2468 if (!match) 2469 return NULL; 2470 2471 info = match->data; 2472 2473 p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL); 2474 if (!p) { 2475 dev_err(&pdev->dev, "failed to allocate DT config data\n"); 2476 return NULL; 2477 } 2478 2479 /* Get the line number for the aliases node. */ 2480 id = of_alias_get_id(np, "serial"); 2481 if (id < 0) { 2482 dev_err(&pdev->dev, "failed to get alias id (%d)\n", id); 2483 return NULL; 2484 } 2485 2486 *dev_id = id; 2487 2488 p->flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF; 2489 p->type = info->type; 2490 p->regtype = info->regtype; 2491 p->scscr = SCSCR_RE | SCSCR_TE; 2492 2493 return p; 2494 } 2495 2496 static int sci_probe_single(struct platform_device *dev, 2497 unsigned int index, 2498 struct plat_sci_port *p, 2499 struct sci_port *sciport) 2500 { 2501 int ret; 2502 2503 /* Sanity check */ 2504 if (unlikely(index >= SCI_NPORTS)) { 2505 dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n", 2506 index+1, SCI_NPORTS); 2507 dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n"); 2508 return -EINVAL; 2509 } 2510 2511 ret = sci_init_single(dev, sciport, index, p, false); 2512 if (ret) 2513 return ret; 2514 2515 ret = uart_add_one_port(&sci_uart_driver, &sciport->port); 2516 if (ret) { 2517 sci_cleanup_single(sciport); 2518 return ret; 2519 } 2520 2521 return 0; 2522 } 2523 2524 static int sci_probe(struct platform_device *dev) 2525 { 2526 struct plat_sci_port *p; 2527 struct sci_port *sp; 2528 unsigned int dev_id; 2529 int ret; 2530 2531 /* 2532 * If we've come here via earlyprintk initialization, head off to 2533 * the special early probe. We don't have sufficient device state 2534 * to make it beyond this yet. 2535 */ 2536 if (is_early_platform_device(dev)) 2537 return sci_probe_earlyprintk(dev); 2538 2539 if (dev->dev.of_node) { 2540 p = sci_parse_dt(dev, &dev_id); 2541 if (p == NULL) 2542 return -EINVAL; 2543 } else { 2544 p = dev->dev.platform_data; 2545 if (p == NULL) { 2546 dev_err(&dev->dev, "no platform data supplied\n"); 2547 return -EINVAL; 2548 } 2549 2550 dev_id = dev->id; 2551 } 2552 2553 sp = &sci_ports[dev_id]; 2554 platform_set_drvdata(dev, sp); 2555 2556 ret = sci_probe_single(dev, dev_id, p, sp); 2557 if (ret) 2558 return ret; 2559 2560 sp->freq_transition.notifier_call = sci_notifier; 2561 2562 ret = cpufreq_register_notifier(&sp->freq_transition, 2563 CPUFREQ_TRANSITION_NOTIFIER); 2564 if (unlikely(ret < 0)) { 2565 uart_remove_one_port(&sci_uart_driver, &sp->port); 2566 sci_cleanup_single(sp); 2567 return ret; 2568 } 2569 2570 #ifdef CONFIG_SH_STANDARD_BIOS 2571 sh_bios_gdb_detach(); 2572 #endif 2573 2574 return 0; 2575 } 2576 2577 static int sci_suspend(struct device *dev) 2578 { 2579 struct sci_port *sport = dev_get_drvdata(dev); 2580 2581 if (sport) 2582 uart_suspend_port(&sci_uart_driver, &sport->port); 2583 2584 return 0; 2585 } 2586 2587 static int sci_resume(struct device *dev) 2588 { 2589 struct sci_port *sport = dev_get_drvdata(dev); 2590 2591 if (sport) 2592 uart_resume_port(&sci_uart_driver, &sport->port); 2593 2594 return 0; 2595 } 2596 2597 static const struct dev_pm_ops sci_dev_pm_ops = { 2598 .suspend = sci_suspend, 2599 .resume = sci_resume, 2600 }; 2601 2602 static struct platform_driver sci_driver = { 2603 .probe = sci_probe, 2604 .remove = sci_remove, 2605 .driver = { 2606 .name = "sh-sci", 2607 .owner = THIS_MODULE, 2608 .pm = &sci_dev_pm_ops, 2609 .of_match_table = of_match_ptr(of_sci_match), 2610 }, 2611 }; 2612 2613 static int __init sci_init(void) 2614 { 2615 int ret; 2616 2617 pr_info("%s\n", banner); 2618 2619 ret = uart_register_driver(&sci_uart_driver); 2620 if (likely(ret == 0)) { 2621 ret = platform_driver_register(&sci_driver); 2622 if (unlikely(ret)) 2623 uart_unregister_driver(&sci_uart_driver); 2624 } 2625 2626 return ret; 2627 } 2628 2629 static void __exit sci_exit(void) 2630 { 2631 platform_driver_unregister(&sci_driver); 2632 uart_unregister_driver(&sci_uart_driver); 2633 } 2634 2635 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE 2636 early_platform_init_buffer("earlyprintk", &sci_driver, 2637 early_serial_buf, ARRAY_SIZE(early_serial_buf)); 2638 #endif 2639 module_init(sci_init); 2640 module_exit(sci_exit); 2641 2642 MODULE_LICENSE("GPL"); 2643 MODULE_ALIAS("platform:sh-sci"); 2644 MODULE_AUTHOR("Paul Mundt"); 2645 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver"); 2646