1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Driver for OMAP-UART controller. 4 * Based on drivers/serial/8250.c 5 * 6 * Copyright (C) 2010 Texas Instruments. 7 * 8 * Authors: 9 * Govindraj R <govindraj.raja@ti.com> 10 * Thara Gopinath <thara@ti.com> 11 * 12 * Note: This driver is made separate from 8250 driver as we cannot 13 * over load 8250 driver with omap platform specific configuration for 14 * features like DMA, it makes easier to implement features like DMA and 15 * hardware flow control and software flow control configuration with 16 * this driver as required for the omap-platform. 17 */ 18 19 #include <linux/module.h> 20 #include <linux/init.h> 21 #include <linux/console.h> 22 #include <linux/serial.h> 23 #include <linux/serial_reg.h> 24 #include <linux/delay.h> 25 #include <linux/slab.h> 26 #include <linux/tty.h> 27 #include <linux/tty_flip.h> 28 #include <linux/platform_device.h> 29 #include <linux/io.h> 30 #include <linux/clk.h> 31 #include <linux/serial_core.h> 32 #include <linux/irq.h> 33 #include <linux/pm_runtime.h> 34 #include <linux/pm_wakeirq.h> 35 #include <linux/of.h> 36 #include <linux/of_irq.h> 37 #include <linux/gpio/consumer.h> 38 #include <linux/platform_data/serial-omap.h> 39 40 #define OMAP_MAX_HSUART_PORTS 10 41 42 #define UART_BUILD_REVISION(x, y) (((x) << 8) | (y)) 43 44 #define OMAP_UART_REV_42 0x0402 45 #define OMAP_UART_REV_46 0x0406 46 #define OMAP_UART_REV_52 0x0502 47 #define OMAP_UART_REV_63 0x0603 48 49 #define OMAP_UART_TX_WAKEUP_EN BIT(7) 50 51 /* Feature flags */ 52 #define OMAP_UART_WER_HAS_TX_WAKEUP BIT(0) 53 54 #define UART_ERRATA_i202_MDR1_ACCESS BIT(0) 55 #define UART_ERRATA_i291_DMA_FORCEIDLE BIT(1) 56 57 #define DEFAULT_CLK_SPEED 48000000 /* 48Mhz */ 58 59 /* SCR register bitmasks */ 60 #define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK (1 << 7) 61 #define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK (1 << 6) 62 #define OMAP_UART_SCR_TX_EMPTY (1 << 3) 63 64 /* FCR register bitmasks */ 65 #define OMAP_UART_FCR_RX_FIFO_TRIG_MASK (0x3 << 6) 66 #define OMAP_UART_FCR_TX_FIFO_TRIG_MASK (0x3 << 4) 67 68 /* MVR register bitmasks */ 69 #define OMAP_UART_MVR_SCHEME_SHIFT 30 70 71 #define OMAP_UART_LEGACY_MVR_MAJ_MASK 0xf0 72 #define OMAP_UART_LEGACY_MVR_MAJ_SHIFT 4 73 #define OMAP_UART_LEGACY_MVR_MIN_MASK 0x0f 74 75 #define OMAP_UART_MVR_MAJ_MASK 0x700 76 #define OMAP_UART_MVR_MAJ_SHIFT 8 77 #define OMAP_UART_MVR_MIN_MASK 0x3f 78 79 #define OMAP_UART_DMA_CH_FREE -1 80 81 #define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA 82 #define OMAP_MODE13X_SPEED 230400 83 84 /* WER = 0x7F 85 * Enable module level wakeup in WER reg 86 */ 87 #define OMAP_UART_WER_MOD_WKUP 0x7F 88 89 /* Enable XON/XOFF flow control on output */ 90 #define OMAP_UART_SW_TX 0x08 91 92 /* Enable XON/XOFF flow control on input */ 93 #define OMAP_UART_SW_RX 0x02 94 95 #define OMAP_UART_SW_CLR 0xF0 96 97 #define OMAP_UART_TCR_TRIG 0x0F 98 99 struct uart_omap_dma { 100 u8 uart_dma_tx; 101 u8 uart_dma_rx; 102 int rx_dma_channel; 103 int tx_dma_channel; 104 dma_addr_t rx_buf_dma_phys; 105 dma_addr_t tx_buf_dma_phys; 106 unsigned int uart_base; 107 /* 108 * Buffer for rx dma. It is not required for tx because the buffer 109 * comes from port structure. 110 */ 111 unsigned char *rx_buf; 112 unsigned int prev_rx_dma_pos; 113 int tx_buf_size; 114 int tx_dma_used; 115 int rx_dma_used; 116 spinlock_t tx_lock; 117 spinlock_t rx_lock; 118 /* timer to poll activity on rx dma */ 119 struct timer_list rx_timer; 120 unsigned int rx_buf_size; 121 unsigned int rx_poll_rate; 122 unsigned int rx_timeout; 123 }; 124 125 struct uart_omap_port { 126 struct uart_port port; 127 struct uart_omap_dma uart_dma; 128 struct device *dev; 129 int wakeirq; 130 131 unsigned char ier; 132 unsigned char lcr; 133 unsigned char mcr; 134 unsigned char fcr; 135 unsigned char efr; 136 unsigned char dll; 137 unsigned char dlh; 138 unsigned char mdr1; 139 unsigned char scr; 140 unsigned char wer; 141 142 int use_dma; 143 /* 144 * Some bits in registers are cleared on a read, so they must 145 * be saved whenever the register is read, but the bits will not 146 * be immediately processed. 147 */ 148 unsigned int lsr_break_flag; 149 unsigned char msr_saved_flags; 150 char name[20]; 151 unsigned long port_activity; 152 int context_loss_cnt; 153 u32 errata; 154 u32 features; 155 156 struct gpio_desc *rts_gpiod; 157 158 struct pm_qos_request pm_qos_request; 159 u32 latency; 160 u32 calc_latency; 161 struct work_struct qos_work; 162 bool is_suspending; 163 164 unsigned int rs485_tx_filter_count; 165 }; 166 167 #define to_uart_omap_port(p) ((container_of((p), struct uart_omap_port, port))) 168 169 static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS]; 170 171 /* Forward declaration of functions */ 172 static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1); 173 174 static inline unsigned int serial_in(struct uart_omap_port *up, int offset) 175 { 176 offset <<= up->port.regshift; 177 return readw(up->port.membase + offset); 178 } 179 180 static inline void serial_out(struct uart_omap_port *up, int offset, int value) 181 { 182 offset <<= up->port.regshift; 183 writew(value, up->port.membase + offset); 184 } 185 186 static inline void serial_omap_clear_fifos(struct uart_omap_port *up) 187 { 188 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); 189 serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | 190 UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); 191 serial_out(up, UART_FCR, 0); 192 } 193 194 #ifdef CONFIG_PM 195 static int serial_omap_get_context_loss_count(struct uart_omap_port *up) 196 { 197 struct omap_uart_port_info *pdata = dev_get_platdata(up->dev); 198 199 if (!pdata || !pdata->get_context_loss_count) 200 return -EINVAL; 201 202 return pdata->get_context_loss_count(up->dev); 203 } 204 205 /* REVISIT: Remove this when omap3 boots in device tree only mode */ 206 static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable) 207 { 208 struct omap_uart_port_info *pdata = dev_get_platdata(up->dev); 209 210 if (!pdata || !pdata->enable_wakeup) 211 return; 212 213 pdata->enable_wakeup(up->dev, enable); 214 } 215 #endif /* CONFIG_PM */ 216 217 /* 218 * Calculate the absolute difference between the desired and actual baud 219 * rate for the given mode. 220 */ 221 static inline int calculate_baud_abs_diff(struct uart_port *port, 222 unsigned int baud, unsigned int mode) 223 { 224 unsigned int n = port->uartclk / (mode * baud); 225 226 if (n == 0) 227 n = 1; 228 229 return abs_diff(baud, port->uartclk / (mode * n)); 230 } 231 232 /* 233 * serial_omap_baud_is_mode16 - check if baud rate is MODE16X 234 * @port: uart port info 235 * @baud: baudrate for which mode needs to be determined 236 * 237 * Returns true if baud rate is MODE16X and false if MODE13X 238 * Original table in OMAP TRM named "UART Mode Baud Rates, Divisor Values, 239 * and Error Rates" determines modes not for all common baud rates. 240 * E.g. for 1000000 baud rate mode must be 16x, but according to that 241 * table it's determined as 13x. 242 */ 243 static bool 244 serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud) 245 { 246 int abs_diff_13 = calculate_baud_abs_diff(port, baud, 13); 247 int abs_diff_16 = calculate_baud_abs_diff(port, baud, 16); 248 249 return (abs_diff_13 >= abs_diff_16); 250 } 251 252 /* 253 * serial_omap_get_divisor - calculate divisor value 254 * @port: uart port info 255 * @baud: baudrate for which divisor needs to be calculated. 256 */ 257 static unsigned int 258 serial_omap_get_divisor(struct uart_port *port, unsigned int baud) 259 { 260 unsigned int mode; 261 262 if (!serial_omap_baud_is_mode16(port, baud)) 263 mode = 13; 264 else 265 mode = 16; 266 return port->uartclk/(mode * baud); 267 } 268 269 static void serial_omap_enable_ms(struct uart_port *port) 270 { 271 struct uart_omap_port *up = to_uart_omap_port(port); 272 273 dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->port.line); 274 275 up->ier |= UART_IER_MSI; 276 serial_out(up, UART_IER, up->ier); 277 } 278 279 static void serial_omap_stop_tx(struct uart_port *port) 280 { 281 struct uart_omap_port *up = to_uart_omap_port(port); 282 int res; 283 284 /* Handle RS-485 */ 285 if (port->rs485.flags & SER_RS485_ENABLED) { 286 if (up->scr & OMAP_UART_SCR_TX_EMPTY) { 287 /* THR interrupt is fired when both TX FIFO and TX 288 * shift register are empty. This means there's nothing 289 * left to transmit now, so make sure the THR interrupt 290 * is fired when TX FIFO is below the trigger level, 291 * disable THR interrupts and toggle the RS-485 GPIO 292 * data direction pin if needed. 293 */ 294 up->scr &= ~OMAP_UART_SCR_TX_EMPTY; 295 serial_out(up, UART_OMAP_SCR, up->scr); 296 res = (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) ? 297 1 : 0; 298 if (gpiod_get_value(up->rts_gpiod) != res) { 299 if (port->rs485.delay_rts_after_send > 0) 300 mdelay( 301 port->rs485.delay_rts_after_send); 302 gpiod_set_value(up->rts_gpiod, res); 303 } 304 } else { 305 /* We're asked to stop, but there's still stuff in the 306 * UART FIFO, so make sure the THR interrupt is fired 307 * when both TX FIFO and TX shift register are empty. 308 * The next THR interrupt (if no transmission is started 309 * in the meantime) will indicate the end of a 310 * transmission. Therefore we _don't_ disable THR 311 * interrupts in this situation. 312 */ 313 up->scr |= OMAP_UART_SCR_TX_EMPTY; 314 serial_out(up, UART_OMAP_SCR, up->scr); 315 return; 316 } 317 } 318 319 if (up->ier & UART_IER_THRI) { 320 up->ier &= ~UART_IER_THRI; 321 serial_out(up, UART_IER, up->ier); 322 } 323 } 324 325 static void serial_omap_stop_rx(struct uart_port *port) 326 { 327 struct uart_omap_port *up = to_uart_omap_port(port); 328 329 up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); 330 up->port.read_status_mask &= ~UART_LSR_DR; 331 serial_out(up, UART_IER, up->ier); 332 } 333 334 static void serial_omap_put_char(struct uart_omap_port *up, unsigned char ch) 335 { 336 serial_out(up, UART_TX, ch); 337 338 if ((up->port.rs485.flags & SER_RS485_ENABLED) && 339 !(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) 340 up->rs485_tx_filter_count++; 341 } 342 343 static void transmit_chars(struct uart_omap_port *up, unsigned int lsr) 344 { 345 u8 ch; 346 347 uart_port_tx_limited(&up->port, ch, up->port.fifosize / 4, 348 true, 349 serial_omap_put_char(up, ch), 350 ({})); 351 } 352 353 static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up) 354 { 355 if (!(up->ier & UART_IER_THRI)) { 356 up->ier |= UART_IER_THRI; 357 serial_out(up, UART_IER, up->ier); 358 } 359 } 360 361 static void serial_omap_start_tx(struct uart_port *port) 362 { 363 struct uart_omap_port *up = to_uart_omap_port(port); 364 int res; 365 366 /* Handle RS-485 */ 367 if (port->rs485.flags & SER_RS485_ENABLED) { 368 /* Fire THR interrupts when FIFO is below trigger level */ 369 up->scr &= ~OMAP_UART_SCR_TX_EMPTY; 370 serial_out(up, UART_OMAP_SCR, up->scr); 371 372 /* if rts not already enabled */ 373 res = (port->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0; 374 if (gpiod_get_value(up->rts_gpiod) != res) { 375 gpiod_set_value(up->rts_gpiod, res); 376 if (port->rs485.delay_rts_before_send > 0) 377 mdelay(port->rs485.delay_rts_before_send); 378 } 379 } 380 381 if ((port->rs485.flags & SER_RS485_ENABLED) && 382 !(port->rs485.flags & SER_RS485_RX_DURING_TX)) 383 up->rs485_tx_filter_count = 0; 384 385 serial_omap_enable_ier_thri(up); 386 } 387 388 static void serial_omap_throttle(struct uart_port *port) 389 { 390 struct uart_omap_port *up = to_uart_omap_port(port); 391 unsigned long flags; 392 393 spin_lock_irqsave(&up->port.lock, flags); 394 up->ier &= ~(UART_IER_RLSI | UART_IER_RDI); 395 serial_out(up, UART_IER, up->ier); 396 spin_unlock_irqrestore(&up->port.lock, flags); 397 } 398 399 static void serial_omap_unthrottle(struct uart_port *port) 400 { 401 struct uart_omap_port *up = to_uart_omap_port(port); 402 unsigned long flags; 403 404 spin_lock_irqsave(&up->port.lock, flags); 405 up->ier |= UART_IER_RLSI | UART_IER_RDI; 406 serial_out(up, UART_IER, up->ier); 407 spin_unlock_irqrestore(&up->port.lock, flags); 408 } 409 410 static unsigned int check_modem_status(struct uart_omap_port *up) 411 { 412 unsigned int status; 413 414 status = serial_in(up, UART_MSR); 415 status |= up->msr_saved_flags; 416 up->msr_saved_flags = 0; 417 if ((status & UART_MSR_ANY_DELTA) == 0) 418 return status; 419 420 if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI && 421 up->port.state != NULL) { 422 if (status & UART_MSR_TERI) 423 up->port.icount.rng++; 424 if (status & UART_MSR_DDSR) 425 up->port.icount.dsr++; 426 if (status & UART_MSR_DDCD) 427 uart_handle_dcd_change 428 (&up->port, status & UART_MSR_DCD); 429 if (status & UART_MSR_DCTS) 430 uart_handle_cts_change 431 (&up->port, status & UART_MSR_CTS); 432 wake_up_interruptible(&up->port.state->port.delta_msr_wait); 433 } 434 435 return status; 436 } 437 438 static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr) 439 { 440 u8 flag; 441 442 /* 443 * Read one data character out to avoid stalling the receiver according 444 * to the table 23-246 of the omap4 TRM. 445 */ 446 if (likely(lsr & UART_LSR_DR)) { 447 serial_in(up, UART_RX); 448 if ((up->port.rs485.flags & SER_RS485_ENABLED) && 449 !(up->port.rs485.flags & SER_RS485_RX_DURING_TX) && 450 up->rs485_tx_filter_count) 451 up->rs485_tx_filter_count--; 452 } 453 454 up->port.icount.rx++; 455 flag = TTY_NORMAL; 456 457 if (lsr & UART_LSR_BI) { 458 flag = TTY_BREAK; 459 lsr &= ~(UART_LSR_FE | UART_LSR_PE); 460 up->port.icount.brk++; 461 /* 462 * We do the SysRQ and SAK checking 463 * here because otherwise the break 464 * may get masked by ignore_status_mask 465 * or read_status_mask. 466 */ 467 if (uart_handle_break(&up->port)) 468 return; 469 470 } 471 472 if (lsr & UART_LSR_PE) { 473 flag = TTY_PARITY; 474 up->port.icount.parity++; 475 } 476 477 if (lsr & UART_LSR_FE) { 478 flag = TTY_FRAME; 479 up->port.icount.frame++; 480 } 481 482 if (lsr & UART_LSR_OE) 483 up->port.icount.overrun++; 484 485 #ifdef CONFIG_SERIAL_OMAP_CONSOLE 486 if (up->port.line == up->port.cons->index) { 487 /* Recover the break flag from console xmit */ 488 lsr |= up->lsr_break_flag; 489 } 490 #endif 491 uart_insert_char(&up->port, lsr, UART_LSR_OE, 0, flag); 492 } 493 494 static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr) 495 { 496 u8 ch; 497 498 if (!(lsr & UART_LSR_DR)) 499 return; 500 501 ch = serial_in(up, UART_RX); 502 if ((up->port.rs485.flags & SER_RS485_ENABLED) && 503 !(up->port.rs485.flags & SER_RS485_RX_DURING_TX) && 504 up->rs485_tx_filter_count) { 505 up->rs485_tx_filter_count--; 506 return; 507 } 508 509 up->port.icount.rx++; 510 511 if (uart_handle_sysrq_char(&up->port, ch)) 512 return; 513 514 uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, TTY_NORMAL); 515 } 516 517 /** 518 * serial_omap_irq() - This handles the interrupt from one port 519 * @irq: uart port irq number 520 * @dev_id: uart port info 521 */ 522 static irqreturn_t serial_omap_irq(int irq, void *dev_id) 523 { 524 struct uart_omap_port *up = dev_id; 525 unsigned int iir, lsr; 526 unsigned int type; 527 irqreturn_t ret = IRQ_NONE; 528 int max_count = 256; 529 530 spin_lock(&up->port.lock); 531 532 do { 533 iir = serial_in(up, UART_IIR); 534 if (iir & UART_IIR_NO_INT) 535 break; 536 537 ret = IRQ_HANDLED; 538 lsr = serial_in(up, UART_LSR); 539 540 /* extract IRQ type from IIR register */ 541 type = iir & 0x3e; 542 543 switch (type) { 544 case UART_IIR_MSI: 545 check_modem_status(up); 546 break; 547 case UART_IIR_THRI: 548 transmit_chars(up, lsr); 549 break; 550 case UART_IIR_RX_TIMEOUT: 551 case UART_IIR_RDI: 552 serial_omap_rdi(up, lsr); 553 break; 554 case UART_IIR_RLSI: 555 serial_omap_rlsi(up, lsr); 556 break; 557 case UART_IIR_CTS_RTS_DSR: 558 /* simply try again */ 559 break; 560 case UART_IIR_XOFF: 561 default: 562 break; 563 } 564 } while (max_count--); 565 566 spin_unlock(&up->port.lock); 567 568 tty_flip_buffer_push(&up->port.state->port); 569 570 up->port_activity = jiffies; 571 572 return ret; 573 } 574 575 static unsigned int serial_omap_tx_empty(struct uart_port *port) 576 { 577 struct uart_omap_port *up = to_uart_omap_port(port); 578 unsigned long flags; 579 unsigned int ret = 0; 580 581 dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->port.line); 582 spin_lock_irqsave(&up->port.lock, flags); 583 ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0; 584 spin_unlock_irqrestore(&up->port.lock, flags); 585 586 return ret; 587 } 588 589 static unsigned int serial_omap_get_mctrl(struct uart_port *port) 590 { 591 struct uart_omap_port *up = to_uart_omap_port(port); 592 unsigned int status; 593 unsigned int ret = 0; 594 595 status = check_modem_status(up); 596 597 dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->port.line); 598 599 if (status & UART_MSR_DCD) 600 ret |= TIOCM_CAR; 601 if (status & UART_MSR_RI) 602 ret |= TIOCM_RNG; 603 if (status & UART_MSR_DSR) 604 ret |= TIOCM_DSR; 605 if (status & UART_MSR_CTS) 606 ret |= TIOCM_CTS; 607 return ret; 608 } 609 610 static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl) 611 { 612 struct uart_omap_port *up = to_uart_omap_port(port); 613 unsigned char mcr = 0, old_mcr, lcr; 614 615 dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->port.line); 616 if (mctrl & TIOCM_RTS) 617 mcr |= UART_MCR_RTS; 618 if (mctrl & TIOCM_DTR) 619 mcr |= UART_MCR_DTR; 620 if (mctrl & TIOCM_OUT1) 621 mcr |= UART_MCR_OUT1; 622 if (mctrl & TIOCM_OUT2) 623 mcr |= UART_MCR_OUT2; 624 if (mctrl & TIOCM_LOOP) 625 mcr |= UART_MCR_LOOP; 626 627 old_mcr = serial_in(up, UART_MCR); 628 old_mcr &= ~(UART_MCR_LOOP | UART_MCR_OUT2 | UART_MCR_OUT1 | 629 UART_MCR_DTR | UART_MCR_RTS); 630 up->mcr = old_mcr | mcr; 631 serial_out(up, UART_MCR, up->mcr); 632 633 /* Turn off autoRTS if RTS is lowered; restore autoRTS if RTS raised */ 634 lcr = serial_in(up, UART_LCR); 635 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 636 if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS)) 637 up->efr |= UART_EFR_RTS; 638 else 639 up->efr &= ~UART_EFR_RTS; 640 serial_out(up, UART_EFR, up->efr); 641 serial_out(up, UART_LCR, lcr); 642 } 643 644 static void serial_omap_break_ctl(struct uart_port *port, int break_state) 645 { 646 struct uart_omap_port *up = to_uart_omap_port(port); 647 unsigned long flags; 648 649 dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->port.line); 650 spin_lock_irqsave(&up->port.lock, flags); 651 if (break_state == -1) 652 up->lcr |= UART_LCR_SBC; 653 else 654 up->lcr &= ~UART_LCR_SBC; 655 serial_out(up, UART_LCR, up->lcr); 656 spin_unlock_irqrestore(&up->port.lock, flags); 657 } 658 659 static int serial_omap_startup(struct uart_port *port) 660 { 661 struct uart_omap_port *up = to_uart_omap_port(port); 662 unsigned long flags; 663 int retval; 664 665 /* 666 * Allocate the IRQ 667 */ 668 retval = request_irq(up->port.irq, serial_omap_irq, up->port.irqflags, 669 up->name, up); 670 if (retval) 671 return retval; 672 673 /* Optional wake-up IRQ */ 674 if (up->wakeirq) { 675 retval = dev_pm_set_dedicated_wake_irq(up->dev, up->wakeirq); 676 if (retval) { 677 free_irq(up->port.irq, up); 678 return retval; 679 } 680 } 681 682 dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->port.line); 683 684 pm_runtime_get_sync(up->dev); 685 /* 686 * Clear the FIFO buffers and disable them. 687 * (they will be reenabled in set_termios()) 688 */ 689 serial_omap_clear_fifos(up); 690 691 /* 692 * Clear the interrupt registers. 693 */ 694 (void) serial_in(up, UART_LSR); 695 if (serial_in(up, UART_LSR) & UART_LSR_DR) 696 (void) serial_in(up, UART_RX); 697 (void) serial_in(up, UART_IIR); 698 (void) serial_in(up, UART_MSR); 699 700 /* 701 * Now, initialize the UART 702 */ 703 serial_out(up, UART_LCR, UART_LCR_WLEN8); 704 spin_lock_irqsave(&up->port.lock, flags); 705 /* 706 * Most PC uarts need OUT2 raised to enable interrupts. 707 */ 708 up->port.mctrl |= TIOCM_OUT2; 709 serial_omap_set_mctrl(&up->port, up->port.mctrl); 710 spin_unlock_irqrestore(&up->port.lock, flags); 711 712 up->msr_saved_flags = 0; 713 /* 714 * Finally, enable interrupts. Note: Modem status interrupts 715 * are set via set_termios(), which will be occurring imminently 716 * anyway, so we don't enable them here. 717 */ 718 up->ier = UART_IER_RLSI | UART_IER_RDI; 719 serial_out(up, UART_IER, up->ier); 720 721 /* Enable module level wake up */ 722 up->wer = OMAP_UART_WER_MOD_WKUP; 723 if (up->features & OMAP_UART_WER_HAS_TX_WAKEUP) 724 up->wer |= OMAP_UART_TX_WAKEUP_EN; 725 726 serial_out(up, UART_OMAP_WER, up->wer); 727 728 up->port_activity = jiffies; 729 return 0; 730 } 731 732 static void serial_omap_shutdown(struct uart_port *port) 733 { 734 struct uart_omap_port *up = to_uart_omap_port(port); 735 unsigned long flags; 736 737 dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->port.line); 738 739 /* 740 * Disable interrupts from this port 741 */ 742 up->ier = 0; 743 serial_out(up, UART_IER, 0); 744 745 spin_lock_irqsave(&up->port.lock, flags); 746 up->port.mctrl &= ~TIOCM_OUT2; 747 serial_omap_set_mctrl(&up->port, up->port.mctrl); 748 spin_unlock_irqrestore(&up->port.lock, flags); 749 750 /* 751 * Disable break condition and FIFOs 752 */ 753 serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC); 754 serial_omap_clear_fifos(up); 755 756 /* 757 * Read data port to reset things, and then free the irq 758 */ 759 if (serial_in(up, UART_LSR) & UART_LSR_DR) 760 (void) serial_in(up, UART_RX); 761 762 pm_runtime_put_sync(up->dev); 763 free_irq(up->port.irq, up); 764 dev_pm_clear_wake_irq(up->dev); 765 } 766 767 static void serial_omap_uart_qos_work(struct work_struct *work) 768 { 769 struct uart_omap_port *up = container_of(work, struct uart_omap_port, 770 qos_work); 771 772 cpu_latency_qos_update_request(&up->pm_qos_request, up->latency); 773 } 774 775 static void 776 serial_omap_set_termios(struct uart_port *port, struct ktermios *termios, 777 const struct ktermios *old) 778 { 779 struct uart_omap_port *up = to_uart_omap_port(port); 780 unsigned char cval = 0; 781 unsigned long flags; 782 unsigned int baud, quot; 783 784 cval = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag)); 785 786 if (termios->c_cflag & CSTOPB) 787 cval |= UART_LCR_STOP; 788 if (termios->c_cflag & PARENB) 789 cval |= UART_LCR_PARITY; 790 if (!(termios->c_cflag & PARODD)) 791 cval |= UART_LCR_EPAR; 792 if (termios->c_cflag & CMSPAR) 793 cval |= UART_LCR_SPAR; 794 795 /* 796 * Ask the core to calculate the divisor for us. 797 */ 798 799 baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13); 800 quot = serial_omap_get_divisor(port, baud); 801 802 /* calculate wakeup latency constraint */ 803 up->calc_latency = (USEC_PER_SEC * up->port.fifosize) / (baud / 8); 804 up->latency = up->calc_latency; 805 schedule_work(&up->qos_work); 806 807 up->dll = quot & 0xff; 808 up->dlh = quot >> 8; 809 up->mdr1 = UART_OMAP_MDR1_DISABLE; 810 811 up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 | 812 UART_FCR_ENABLE_FIFO; 813 814 /* 815 * Ok, we're now changing the port state. Do it with 816 * interrupts disabled. 817 */ 818 spin_lock_irqsave(&up->port.lock, flags); 819 820 /* 821 * Update the per-port timeout. 822 */ 823 uart_update_timeout(port, termios->c_cflag, baud); 824 825 up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR; 826 if (termios->c_iflag & INPCK) 827 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE; 828 if (termios->c_iflag & (BRKINT | PARMRK)) 829 up->port.read_status_mask |= UART_LSR_BI; 830 831 /* 832 * Characters to ignore 833 */ 834 up->port.ignore_status_mask = 0; 835 if (termios->c_iflag & IGNPAR) 836 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE; 837 if (termios->c_iflag & IGNBRK) { 838 up->port.ignore_status_mask |= UART_LSR_BI; 839 /* 840 * If we're ignoring parity and break indicators, 841 * ignore overruns too (for real raw support). 842 */ 843 if (termios->c_iflag & IGNPAR) 844 up->port.ignore_status_mask |= UART_LSR_OE; 845 } 846 847 /* 848 * ignore all characters if CREAD is not set 849 */ 850 if ((termios->c_cflag & CREAD) == 0) 851 up->port.ignore_status_mask |= UART_LSR_DR; 852 853 /* 854 * Modem status interrupts 855 */ 856 up->ier &= ~UART_IER_MSI; 857 if (UART_ENABLE_MS(&up->port, termios->c_cflag)) 858 up->ier |= UART_IER_MSI; 859 serial_out(up, UART_IER, up->ier); 860 serial_out(up, UART_LCR, cval); /* reset DLAB */ 861 up->lcr = cval; 862 up->scr = 0; 863 864 /* FIFOs and DMA Settings */ 865 866 /* FCR can be changed only when the 867 * baud clock is not running 868 * DLL_REG and DLH_REG set to 0. 869 */ 870 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); 871 serial_out(up, UART_DLL, 0); 872 serial_out(up, UART_DLM, 0); 873 serial_out(up, UART_LCR, 0); 874 875 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 876 877 up->efr = serial_in(up, UART_EFR) & ~UART_EFR_ECB; 878 up->efr &= ~UART_EFR_SCD; 879 serial_out(up, UART_EFR, up->efr | UART_EFR_ECB); 880 881 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); 882 up->mcr = serial_in(up, UART_MCR) & ~UART_MCR_TCRTLR; 883 serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR); 884 /* FIFO ENABLE, DMA MODE */ 885 886 up->scr |= OMAP_UART_SCR_RX_TRIG_GRANU1_MASK; 887 /* 888 * NOTE: Setting OMAP_UART_SCR_RX_TRIG_GRANU1_MASK 889 * sets Enables the granularity of 1 for TRIGGER RX 890 * level. Along with setting RX FIFO trigger level 891 * to 1 (as noted below, 16 characters) and TLR[3:0] 892 * to zero this will result RX FIFO threshold level 893 * to 1 character, instead of 16 as noted in comment 894 * below. 895 */ 896 897 /* Set receive FIFO threshold to 16 characters and 898 * transmit FIFO threshold to 32 spaces 899 */ 900 up->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK; 901 up->fcr &= ~OMAP_UART_FCR_TX_FIFO_TRIG_MASK; 902 up->fcr |= UART_FCR6_R_TRIGGER_16 | UART_FCR6_T_TRIGGER_24 | 903 UART_FCR_ENABLE_FIFO; 904 905 serial_out(up, UART_FCR, up->fcr); 906 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 907 908 serial_out(up, UART_OMAP_SCR, up->scr); 909 910 /* Reset UART_MCR_TCRTLR: this must be done with the EFR_ECB bit set */ 911 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); 912 serial_out(up, UART_MCR, up->mcr); 913 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 914 serial_out(up, UART_EFR, up->efr); 915 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); 916 917 /* Protocol, Baud Rate, and Interrupt Settings */ 918 919 if (up->errata & UART_ERRATA_i202_MDR1_ACCESS) 920 serial_omap_mdr1_errataset(up, up->mdr1); 921 else 922 serial_out(up, UART_OMAP_MDR1, up->mdr1); 923 924 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 925 serial_out(up, UART_EFR, up->efr | UART_EFR_ECB); 926 927 serial_out(up, UART_LCR, 0); 928 serial_out(up, UART_IER, 0); 929 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 930 931 serial_out(up, UART_DLL, up->dll); /* LS of divisor */ 932 serial_out(up, UART_DLM, up->dlh); /* MS of divisor */ 933 934 serial_out(up, UART_LCR, 0); 935 serial_out(up, UART_IER, up->ier); 936 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 937 938 serial_out(up, UART_EFR, up->efr); 939 serial_out(up, UART_LCR, cval); 940 941 if (!serial_omap_baud_is_mode16(port, baud)) 942 up->mdr1 = UART_OMAP_MDR1_13X_MODE; 943 else 944 up->mdr1 = UART_OMAP_MDR1_16X_MODE; 945 946 if (up->errata & UART_ERRATA_i202_MDR1_ACCESS) 947 serial_omap_mdr1_errataset(up, up->mdr1); 948 else 949 serial_out(up, UART_OMAP_MDR1, up->mdr1); 950 951 /* Configure flow control */ 952 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 953 954 /* XON1/XOFF1 accessible mode B, TCRTLR=0, ECB=0 */ 955 serial_out(up, UART_XON1, termios->c_cc[VSTART]); 956 serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]); 957 958 /* Enable access to TCR/TLR */ 959 serial_out(up, UART_EFR, up->efr | UART_EFR_ECB); 960 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); 961 serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR); 962 963 serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG); 964 965 up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF); 966 967 if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) { 968 /* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */ 969 up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS; 970 up->efr |= UART_EFR_CTS; 971 } else { 972 /* Disable AUTORTS and AUTOCTS */ 973 up->efr &= ~(UART_EFR_CTS | UART_EFR_RTS); 974 } 975 976 if (up->port.flags & UPF_SOFT_FLOW) { 977 /* clear SW control mode bits */ 978 up->efr &= OMAP_UART_SW_CLR; 979 980 /* 981 * IXON Flag: 982 * Enable XON/XOFF flow control on input. 983 * Receiver compares XON1, XOFF1. 984 */ 985 if (termios->c_iflag & IXON) 986 up->efr |= OMAP_UART_SW_RX; 987 988 /* 989 * IXOFF Flag: 990 * Enable XON/XOFF flow control on output. 991 * Transmit XON1, XOFF1 992 */ 993 if (termios->c_iflag & IXOFF) { 994 up->port.status |= UPSTAT_AUTOXOFF; 995 up->efr |= OMAP_UART_SW_TX; 996 } 997 998 /* 999 * IXANY Flag: 1000 * Enable any character to restart output. 1001 * Operation resumes after receiving any 1002 * character after recognition of the XOFF character 1003 */ 1004 if (termios->c_iflag & IXANY) 1005 up->mcr |= UART_MCR_XONANY; 1006 else 1007 up->mcr &= ~UART_MCR_XONANY; 1008 } 1009 serial_out(up, UART_MCR, up->mcr); 1010 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 1011 serial_out(up, UART_EFR, up->efr); 1012 serial_out(up, UART_LCR, up->lcr); 1013 1014 serial_omap_set_mctrl(&up->port, up->port.mctrl); 1015 1016 spin_unlock_irqrestore(&up->port.lock, flags); 1017 dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->port.line); 1018 } 1019 1020 static void 1021 serial_omap_pm(struct uart_port *port, unsigned int state, 1022 unsigned int oldstate) 1023 { 1024 struct uart_omap_port *up = to_uart_omap_port(port); 1025 unsigned char efr; 1026 1027 dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->port.line); 1028 1029 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 1030 efr = serial_in(up, UART_EFR); 1031 serial_out(up, UART_EFR, efr | UART_EFR_ECB); 1032 serial_out(up, UART_LCR, 0); 1033 1034 serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0); 1035 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); 1036 serial_out(up, UART_EFR, efr); 1037 serial_out(up, UART_LCR, 0); 1038 } 1039 1040 static void serial_omap_release_port(struct uart_port *port) 1041 { 1042 dev_dbg(port->dev, "serial_omap_release_port+\n"); 1043 } 1044 1045 static int serial_omap_request_port(struct uart_port *port) 1046 { 1047 dev_dbg(port->dev, "serial_omap_request_port+\n"); 1048 return 0; 1049 } 1050 1051 static void serial_omap_config_port(struct uart_port *port, int flags) 1052 { 1053 struct uart_omap_port *up = to_uart_omap_port(port); 1054 1055 dev_dbg(up->port.dev, "serial_omap_config_port+%d\n", 1056 up->port.line); 1057 up->port.type = PORT_OMAP; 1058 up->port.flags |= UPF_SOFT_FLOW | UPF_HARD_FLOW; 1059 } 1060 1061 static int 1062 serial_omap_verify_port(struct uart_port *port, struct serial_struct *ser) 1063 { 1064 /* we don't want the core code to modify any port params */ 1065 dev_dbg(port->dev, "serial_omap_verify_port+\n"); 1066 return -EINVAL; 1067 } 1068 1069 static const char * 1070 serial_omap_type(struct uart_port *port) 1071 { 1072 struct uart_omap_port *up = to_uart_omap_port(port); 1073 1074 dev_dbg(up->port.dev, "serial_omap_type+%d\n", up->port.line); 1075 return up->name; 1076 } 1077 1078 static void __maybe_unused wait_for_xmitr(struct uart_omap_port *up) 1079 { 1080 unsigned int status, tmout = 10000; 1081 1082 /* Wait up to 10ms for the character(s) to be sent. */ 1083 do { 1084 status = serial_in(up, UART_LSR); 1085 1086 if (status & UART_LSR_BI) 1087 up->lsr_break_flag = UART_LSR_BI; 1088 1089 if (--tmout == 0) 1090 break; 1091 udelay(1); 1092 } while (!uart_lsr_tx_empty(status)); 1093 1094 /* Wait up to 1s for flow control if necessary */ 1095 if (up->port.flags & UPF_CONS_FLOW) { 1096 tmout = 1000000; 1097 for (tmout = 1000000; tmout; tmout--) { 1098 unsigned int msr = serial_in(up, UART_MSR); 1099 1100 up->msr_saved_flags |= msr & MSR_SAVE_FLAGS; 1101 if (msr & UART_MSR_CTS) 1102 break; 1103 1104 udelay(1); 1105 } 1106 } 1107 } 1108 1109 #ifdef CONFIG_CONSOLE_POLL 1110 1111 static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch) 1112 { 1113 struct uart_omap_port *up = to_uart_omap_port(port); 1114 1115 wait_for_xmitr(up); 1116 serial_out(up, UART_TX, ch); 1117 } 1118 1119 static int serial_omap_poll_get_char(struct uart_port *port) 1120 { 1121 struct uart_omap_port *up = to_uart_omap_port(port); 1122 unsigned int status; 1123 1124 status = serial_in(up, UART_LSR); 1125 if (!(status & UART_LSR_DR)) { 1126 status = NO_POLL_CHAR; 1127 goto out; 1128 } 1129 1130 status = serial_in(up, UART_RX); 1131 1132 out: 1133 return status; 1134 } 1135 1136 #endif /* CONFIG_CONSOLE_POLL */ 1137 1138 #ifdef CONFIG_SERIAL_OMAP_CONSOLE 1139 1140 #ifdef CONFIG_SERIAL_EARLYCON 1141 static unsigned int omap_serial_early_in(struct uart_port *port, int offset) 1142 { 1143 offset <<= port->regshift; 1144 return readw(port->membase + offset); 1145 } 1146 1147 static void omap_serial_early_out(struct uart_port *port, int offset, 1148 int value) 1149 { 1150 offset <<= port->regshift; 1151 writew(value, port->membase + offset); 1152 } 1153 1154 static void omap_serial_early_putc(struct uart_port *port, unsigned char c) 1155 { 1156 unsigned int status; 1157 1158 for (;;) { 1159 status = omap_serial_early_in(port, UART_LSR); 1160 if (uart_lsr_tx_empty(status)) 1161 break; 1162 cpu_relax(); 1163 } 1164 omap_serial_early_out(port, UART_TX, c); 1165 } 1166 1167 static void early_omap_serial_write(struct console *console, const char *s, 1168 unsigned int count) 1169 { 1170 struct earlycon_device *device = console->data; 1171 struct uart_port *port = &device->port; 1172 1173 uart_console_write(port, s, count, omap_serial_early_putc); 1174 } 1175 1176 static int __init early_omap_serial_setup(struct earlycon_device *device, 1177 const char *options) 1178 { 1179 struct uart_port *port = &device->port; 1180 1181 if (!(device->port.membase || device->port.iobase)) 1182 return -ENODEV; 1183 1184 port->regshift = 2; 1185 device->con->write = early_omap_serial_write; 1186 return 0; 1187 } 1188 1189 OF_EARLYCON_DECLARE(omapserial, "ti,omap2-uart", early_omap_serial_setup); 1190 OF_EARLYCON_DECLARE(omapserial, "ti,omap3-uart", early_omap_serial_setup); 1191 OF_EARLYCON_DECLARE(omapserial, "ti,omap4-uart", early_omap_serial_setup); 1192 #endif /* CONFIG_SERIAL_EARLYCON */ 1193 1194 static struct uart_omap_port *serial_omap_console_ports[OMAP_MAX_HSUART_PORTS]; 1195 1196 static struct uart_driver serial_omap_reg; 1197 1198 static void serial_omap_console_putchar(struct uart_port *port, unsigned char ch) 1199 { 1200 struct uart_omap_port *up = to_uart_omap_port(port); 1201 1202 wait_for_xmitr(up); 1203 serial_out(up, UART_TX, ch); 1204 } 1205 1206 static void 1207 serial_omap_console_write(struct console *co, const char *s, 1208 unsigned int count) 1209 { 1210 struct uart_omap_port *up = serial_omap_console_ports[co->index]; 1211 unsigned long flags; 1212 unsigned int ier; 1213 int locked = 1; 1214 1215 local_irq_save(flags); 1216 if (up->port.sysrq) 1217 locked = 0; 1218 else if (oops_in_progress) 1219 locked = spin_trylock(&up->port.lock); 1220 else 1221 spin_lock(&up->port.lock); 1222 1223 /* 1224 * First save the IER then disable the interrupts 1225 */ 1226 ier = serial_in(up, UART_IER); 1227 serial_out(up, UART_IER, 0); 1228 1229 uart_console_write(&up->port, s, count, serial_omap_console_putchar); 1230 1231 /* 1232 * Finally, wait for transmitter to become empty 1233 * and restore the IER 1234 */ 1235 wait_for_xmitr(up); 1236 serial_out(up, UART_IER, ier); 1237 /* 1238 * The receive handling will happen properly because the 1239 * receive ready bit will still be set; it is not cleared 1240 * on read. However, modem control will not, we must 1241 * call it if we have saved something in the saved flags 1242 * while processing with interrupts off. 1243 */ 1244 if (up->msr_saved_flags) 1245 check_modem_status(up); 1246 1247 if (locked) 1248 spin_unlock(&up->port.lock); 1249 local_irq_restore(flags); 1250 } 1251 1252 static int __init 1253 serial_omap_console_setup(struct console *co, char *options) 1254 { 1255 struct uart_omap_port *up; 1256 int baud = 115200; 1257 int bits = 8; 1258 int parity = 'n'; 1259 int flow = 'n'; 1260 1261 if (serial_omap_console_ports[co->index] == NULL) 1262 return -ENODEV; 1263 up = serial_omap_console_ports[co->index]; 1264 1265 if (options) 1266 uart_parse_options(options, &baud, &parity, &bits, &flow); 1267 1268 return uart_set_options(&up->port, co, baud, parity, bits, flow); 1269 } 1270 1271 static struct console serial_omap_console = { 1272 .name = OMAP_SERIAL_NAME, 1273 .write = serial_omap_console_write, 1274 .device = uart_console_device, 1275 .setup = serial_omap_console_setup, 1276 .flags = CON_PRINTBUFFER, 1277 .index = -1, 1278 .data = &serial_omap_reg, 1279 }; 1280 1281 static void serial_omap_add_console_port(struct uart_omap_port *up) 1282 { 1283 serial_omap_console_ports[up->port.line] = up; 1284 } 1285 1286 #define OMAP_CONSOLE (&serial_omap_console) 1287 1288 #else 1289 1290 #define OMAP_CONSOLE NULL 1291 1292 static inline void serial_omap_add_console_port(struct uart_omap_port *up) 1293 {} 1294 1295 #endif 1296 1297 /* Enable or disable the rs485 support */ 1298 static int 1299 serial_omap_config_rs485(struct uart_port *port, struct ktermios *termios, 1300 struct serial_rs485 *rs485) 1301 { 1302 struct uart_omap_port *up = to_uart_omap_port(port); 1303 unsigned int mode; 1304 int val; 1305 1306 /* Disable interrupts from this port */ 1307 mode = up->ier; 1308 up->ier = 0; 1309 serial_out(up, UART_IER, 0); 1310 1311 /* enable / disable rts */ 1312 val = (rs485->flags & SER_RS485_ENABLED) ? 1313 SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND; 1314 val = (rs485->flags & val) ? 1 : 0; 1315 gpiod_set_value(up->rts_gpiod, val); 1316 1317 /* Enable interrupts */ 1318 up->ier = mode; 1319 serial_out(up, UART_IER, up->ier); 1320 1321 /* If RS-485 is disabled, make sure the THR interrupt is fired when 1322 * TX FIFO is below the trigger level. 1323 */ 1324 if (!(rs485->flags & SER_RS485_ENABLED) && 1325 (up->scr & OMAP_UART_SCR_TX_EMPTY)) { 1326 up->scr &= ~OMAP_UART_SCR_TX_EMPTY; 1327 serial_out(up, UART_OMAP_SCR, up->scr); 1328 } 1329 1330 return 0; 1331 } 1332 1333 static const struct uart_ops serial_omap_pops = { 1334 .tx_empty = serial_omap_tx_empty, 1335 .set_mctrl = serial_omap_set_mctrl, 1336 .get_mctrl = serial_omap_get_mctrl, 1337 .stop_tx = serial_omap_stop_tx, 1338 .start_tx = serial_omap_start_tx, 1339 .throttle = serial_omap_throttle, 1340 .unthrottle = serial_omap_unthrottle, 1341 .stop_rx = serial_omap_stop_rx, 1342 .enable_ms = serial_omap_enable_ms, 1343 .break_ctl = serial_omap_break_ctl, 1344 .startup = serial_omap_startup, 1345 .shutdown = serial_omap_shutdown, 1346 .set_termios = serial_omap_set_termios, 1347 .pm = serial_omap_pm, 1348 .type = serial_omap_type, 1349 .release_port = serial_omap_release_port, 1350 .request_port = serial_omap_request_port, 1351 .config_port = serial_omap_config_port, 1352 .verify_port = serial_omap_verify_port, 1353 #ifdef CONFIG_CONSOLE_POLL 1354 .poll_put_char = serial_omap_poll_put_char, 1355 .poll_get_char = serial_omap_poll_get_char, 1356 #endif 1357 }; 1358 1359 static struct uart_driver serial_omap_reg = { 1360 .owner = THIS_MODULE, 1361 .driver_name = "OMAP-SERIAL", 1362 .dev_name = OMAP_SERIAL_NAME, 1363 .nr = OMAP_MAX_HSUART_PORTS, 1364 .cons = OMAP_CONSOLE, 1365 }; 1366 1367 #ifdef CONFIG_PM_SLEEP 1368 static int serial_omap_prepare(struct device *dev) 1369 { 1370 struct uart_omap_port *up = dev_get_drvdata(dev); 1371 1372 up->is_suspending = true; 1373 1374 return 0; 1375 } 1376 1377 static void serial_omap_complete(struct device *dev) 1378 { 1379 struct uart_omap_port *up = dev_get_drvdata(dev); 1380 1381 up->is_suspending = false; 1382 } 1383 1384 static int serial_omap_suspend(struct device *dev) 1385 { 1386 struct uart_omap_port *up = dev_get_drvdata(dev); 1387 1388 uart_suspend_port(&serial_omap_reg, &up->port); 1389 flush_work(&up->qos_work); 1390 1391 if (device_may_wakeup(dev)) 1392 serial_omap_enable_wakeup(up, true); 1393 else 1394 serial_omap_enable_wakeup(up, false); 1395 1396 return 0; 1397 } 1398 1399 static int serial_omap_resume(struct device *dev) 1400 { 1401 struct uart_omap_port *up = dev_get_drvdata(dev); 1402 1403 if (device_may_wakeup(dev)) 1404 serial_omap_enable_wakeup(up, false); 1405 1406 uart_resume_port(&serial_omap_reg, &up->port); 1407 1408 return 0; 1409 } 1410 #else 1411 #define serial_omap_prepare NULL 1412 #define serial_omap_complete NULL 1413 #endif /* CONFIG_PM_SLEEP */ 1414 1415 static void omap_serial_fill_features_erratas(struct uart_omap_port *up) 1416 { 1417 u32 mvr, scheme; 1418 u16 revision, major, minor; 1419 1420 mvr = readl(up->port.membase + (UART_OMAP_MVER << up->port.regshift)); 1421 1422 /* Check revision register scheme */ 1423 scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT; 1424 1425 switch (scheme) { 1426 case 0: /* Legacy Scheme: OMAP2/3 */ 1427 /* MINOR_REV[0:4], MAJOR_REV[4:7] */ 1428 major = (mvr & OMAP_UART_LEGACY_MVR_MAJ_MASK) >> 1429 OMAP_UART_LEGACY_MVR_MAJ_SHIFT; 1430 minor = (mvr & OMAP_UART_LEGACY_MVR_MIN_MASK); 1431 break; 1432 case 1: 1433 /* New Scheme: OMAP4+ */ 1434 /* MINOR_REV[0:5], MAJOR_REV[8:10] */ 1435 major = (mvr & OMAP_UART_MVR_MAJ_MASK) >> 1436 OMAP_UART_MVR_MAJ_SHIFT; 1437 minor = (mvr & OMAP_UART_MVR_MIN_MASK); 1438 break; 1439 default: 1440 dev_warn(up->dev, 1441 "Unknown %s revision, defaulting to highest\n", 1442 up->name); 1443 /* highest possible revision */ 1444 major = 0xff; 1445 minor = 0xff; 1446 } 1447 1448 /* normalize revision for the driver */ 1449 revision = UART_BUILD_REVISION(major, minor); 1450 1451 switch (revision) { 1452 case OMAP_UART_REV_46: 1453 up->errata |= (UART_ERRATA_i202_MDR1_ACCESS | 1454 UART_ERRATA_i291_DMA_FORCEIDLE); 1455 break; 1456 case OMAP_UART_REV_52: 1457 up->errata |= (UART_ERRATA_i202_MDR1_ACCESS | 1458 UART_ERRATA_i291_DMA_FORCEIDLE); 1459 up->features |= OMAP_UART_WER_HAS_TX_WAKEUP; 1460 break; 1461 case OMAP_UART_REV_63: 1462 up->errata |= UART_ERRATA_i202_MDR1_ACCESS; 1463 up->features |= OMAP_UART_WER_HAS_TX_WAKEUP; 1464 break; 1465 default: 1466 break; 1467 } 1468 } 1469 1470 static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev) 1471 { 1472 struct omap_uart_port_info *omap_up_info; 1473 1474 omap_up_info = devm_kzalloc(dev, sizeof(*omap_up_info), GFP_KERNEL); 1475 if (!omap_up_info) 1476 return NULL; /* out of memory */ 1477 1478 of_property_read_u32(dev->of_node, "clock-frequency", 1479 &omap_up_info->uartclk); 1480 1481 omap_up_info->flags = UPF_BOOT_AUTOCONF; 1482 1483 return omap_up_info; 1484 } 1485 1486 static int serial_omap_probe_rs485(struct uart_omap_port *up, 1487 struct device *dev) 1488 { 1489 struct serial_rs485 *rs485conf = &up->port.rs485; 1490 struct device_node *np = dev->of_node; 1491 enum gpiod_flags gflags; 1492 int ret; 1493 1494 rs485conf->flags = 0; 1495 up->rts_gpiod = NULL; 1496 1497 if (!np) 1498 return 0; 1499 1500 ret = uart_get_rs485_mode(&up->port); 1501 if (ret) 1502 return ret; 1503 1504 if (of_property_read_bool(np, "rs485-rts-active-high")) { 1505 rs485conf->flags |= SER_RS485_RTS_ON_SEND; 1506 rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND; 1507 } else { 1508 rs485conf->flags &= ~SER_RS485_RTS_ON_SEND; 1509 rs485conf->flags |= SER_RS485_RTS_AFTER_SEND; 1510 } 1511 1512 /* check for tx enable gpio */ 1513 gflags = rs485conf->flags & SER_RS485_RTS_AFTER_SEND ? 1514 GPIOD_OUT_HIGH : GPIOD_OUT_LOW; 1515 up->rts_gpiod = devm_gpiod_get_optional(dev, "rts", gflags); 1516 if (IS_ERR(up->rts_gpiod)) { 1517 ret = PTR_ERR(up->rts_gpiod); 1518 if (ret == -EPROBE_DEFER) 1519 return ret; 1520 1521 up->rts_gpiod = NULL; 1522 up->port.rs485_supported = (const struct serial_rs485) { }; 1523 if (rs485conf->flags & SER_RS485_ENABLED) { 1524 dev_err(dev, "disabling RS-485 (rts-gpio missing in device tree)\n"); 1525 memset(rs485conf, 0, sizeof(*rs485conf)); 1526 } 1527 } else { 1528 gpiod_set_consumer_name(up->rts_gpiod, "omap-serial"); 1529 } 1530 1531 return 0; 1532 } 1533 1534 static const struct serial_rs485 serial_omap_rs485_supported = { 1535 .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND | 1536 SER_RS485_RX_DURING_TX, 1537 .delay_rts_before_send = 1, 1538 .delay_rts_after_send = 1, 1539 }; 1540 1541 static int serial_omap_probe(struct platform_device *pdev) 1542 { 1543 struct omap_uart_port_info *omap_up_info = dev_get_platdata(&pdev->dev); 1544 struct uart_omap_port *up; 1545 struct resource *mem; 1546 void __iomem *base; 1547 int uartirq = 0; 1548 int wakeirq = 0; 1549 int ret; 1550 1551 /* The optional wakeirq may be specified in the board dts file */ 1552 if (pdev->dev.of_node) { 1553 uartirq = irq_of_parse_and_map(pdev->dev.of_node, 0); 1554 if (!uartirq) 1555 return -EPROBE_DEFER; 1556 wakeirq = irq_of_parse_and_map(pdev->dev.of_node, 1); 1557 omap_up_info = of_get_uart_port_info(&pdev->dev); 1558 pdev->dev.platform_data = omap_up_info; 1559 } else { 1560 uartirq = platform_get_irq(pdev, 0); 1561 if (uartirq < 0) 1562 return -EPROBE_DEFER; 1563 } 1564 1565 up = devm_kzalloc(&pdev->dev, sizeof(*up), GFP_KERNEL); 1566 if (!up) 1567 return -ENOMEM; 1568 1569 base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem); 1570 if (IS_ERR(base)) 1571 return PTR_ERR(base); 1572 1573 up->dev = &pdev->dev; 1574 up->port.dev = &pdev->dev; 1575 up->port.type = PORT_OMAP; 1576 up->port.iotype = UPIO_MEM; 1577 up->port.irq = uartirq; 1578 up->port.regshift = 2; 1579 up->port.fifosize = 64; 1580 up->port.ops = &serial_omap_pops; 1581 up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_OMAP_CONSOLE); 1582 1583 if (pdev->dev.of_node) 1584 ret = of_alias_get_id(pdev->dev.of_node, "serial"); 1585 else 1586 ret = pdev->id; 1587 1588 if (ret < 0) { 1589 dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n", 1590 ret); 1591 goto err_port_line; 1592 } 1593 up->port.line = ret; 1594 1595 if (up->port.line >= OMAP_MAX_HSUART_PORTS) { 1596 dev_err(&pdev->dev, "uart ID %d > MAX %d.\n", up->port.line, 1597 OMAP_MAX_HSUART_PORTS); 1598 ret = -ENXIO; 1599 goto err_port_line; 1600 } 1601 1602 up->wakeirq = wakeirq; 1603 if (!up->wakeirq) 1604 dev_info(up->port.dev, "no wakeirq for uart%d\n", 1605 up->port.line); 1606 1607 ret = serial_omap_probe_rs485(up, &pdev->dev); 1608 if (ret < 0) 1609 goto err_rs485; 1610 1611 sprintf(up->name, "OMAP UART%d", up->port.line); 1612 up->port.mapbase = mem->start; 1613 up->port.membase = base; 1614 up->port.flags = omap_up_info->flags; 1615 up->port.uartclk = omap_up_info->uartclk; 1616 up->port.rs485_config = serial_omap_config_rs485; 1617 up->port.rs485_supported = serial_omap_rs485_supported; 1618 if (!up->port.uartclk) { 1619 up->port.uartclk = DEFAULT_CLK_SPEED; 1620 dev_warn(&pdev->dev, 1621 "No clock speed specified: using default: %d\n", 1622 DEFAULT_CLK_SPEED); 1623 } 1624 1625 up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; 1626 up->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; 1627 cpu_latency_qos_add_request(&up->pm_qos_request, up->latency); 1628 INIT_WORK(&up->qos_work, serial_omap_uart_qos_work); 1629 1630 platform_set_drvdata(pdev, up); 1631 if (omap_up_info->autosuspend_timeout == 0) 1632 omap_up_info->autosuspend_timeout = -1; 1633 1634 device_init_wakeup(up->dev, true); 1635 1636 pm_runtime_enable(&pdev->dev); 1637 1638 pm_runtime_get_sync(&pdev->dev); 1639 1640 omap_serial_fill_features_erratas(up); 1641 1642 ui[up->port.line] = up; 1643 serial_omap_add_console_port(up); 1644 1645 ret = uart_add_one_port(&serial_omap_reg, &up->port); 1646 if (ret != 0) 1647 goto err_add_port; 1648 1649 return 0; 1650 1651 err_add_port: 1652 pm_runtime_put_sync(&pdev->dev); 1653 pm_runtime_disable(&pdev->dev); 1654 cpu_latency_qos_remove_request(&up->pm_qos_request); 1655 device_init_wakeup(up->dev, false); 1656 err_rs485: 1657 err_port_line: 1658 return ret; 1659 } 1660 1661 static int serial_omap_remove(struct platform_device *dev) 1662 { 1663 struct uart_omap_port *up = platform_get_drvdata(dev); 1664 1665 pm_runtime_get_sync(up->dev); 1666 1667 uart_remove_one_port(&serial_omap_reg, &up->port); 1668 1669 pm_runtime_put_sync(up->dev); 1670 pm_runtime_disable(up->dev); 1671 cpu_latency_qos_remove_request(&up->pm_qos_request); 1672 device_init_wakeup(&dev->dev, false); 1673 1674 return 0; 1675 } 1676 1677 /* 1678 * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460) 1679 * The access to uart register after MDR1 Access 1680 * causes UART to corrupt data. 1681 * 1682 * Need a delay = 1683 * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS) 1684 * give 10 times as much 1685 */ 1686 static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1) 1687 { 1688 u8 timeout = 255; 1689 1690 serial_out(up, UART_OMAP_MDR1, mdr1); 1691 udelay(2); 1692 serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT | 1693 UART_FCR_CLEAR_RCVR); 1694 /* 1695 * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and 1696 * TX_FIFO_E bit is 1. 1697 */ 1698 while (UART_LSR_THRE != (serial_in(up, UART_LSR) & 1699 (UART_LSR_THRE | UART_LSR_DR))) { 1700 timeout--; 1701 if (!timeout) { 1702 /* Should *never* happen. we warn and carry on */ 1703 dev_crit(up->dev, "Errata i202: timedout %x\n", 1704 serial_in(up, UART_LSR)); 1705 break; 1706 } 1707 udelay(1); 1708 } 1709 } 1710 1711 #ifdef CONFIG_PM 1712 static void serial_omap_restore_context(struct uart_omap_port *up) 1713 { 1714 if (up->errata & UART_ERRATA_i202_MDR1_ACCESS) 1715 serial_omap_mdr1_errataset(up, UART_OMAP_MDR1_DISABLE); 1716 else 1717 serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE); 1718 1719 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */ 1720 serial_out(up, UART_EFR, UART_EFR_ECB); 1721 serial_out(up, UART_LCR, 0x0); /* Operational mode */ 1722 serial_out(up, UART_IER, 0x0); 1723 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */ 1724 serial_out(up, UART_DLL, up->dll); 1725 serial_out(up, UART_DLM, up->dlh); 1726 serial_out(up, UART_LCR, 0x0); /* Operational mode */ 1727 serial_out(up, UART_IER, up->ier); 1728 serial_out(up, UART_FCR, up->fcr); 1729 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); 1730 serial_out(up, UART_MCR, up->mcr); 1731 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */ 1732 serial_out(up, UART_OMAP_SCR, up->scr); 1733 serial_out(up, UART_EFR, up->efr); 1734 serial_out(up, UART_LCR, up->lcr); 1735 if (up->errata & UART_ERRATA_i202_MDR1_ACCESS) 1736 serial_omap_mdr1_errataset(up, up->mdr1); 1737 else 1738 serial_out(up, UART_OMAP_MDR1, up->mdr1); 1739 serial_out(up, UART_OMAP_WER, up->wer); 1740 } 1741 1742 static int serial_omap_runtime_suspend(struct device *dev) 1743 { 1744 struct uart_omap_port *up = dev_get_drvdata(dev); 1745 1746 if (!up) 1747 return -EINVAL; 1748 1749 /* 1750 * When using 'no_console_suspend', the console UART must not be 1751 * suspended. Since driver suspend is managed by runtime suspend, 1752 * preventing runtime suspend (by returning error) will keep device 1753 * active during suspend. 1754 */ 1755 if (up->is_suspending && !console_suspend_enabled && 1756 uart_console(&up->port)) 1757 return -EBUSY; 1758 1759 up->context_loss_cnt = serial_omap_get_context_loss_count(up); 1760 1761 serial_omap_enable_wakeup(up, true); 1762 1763 up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE; 1764 schedule_work(&up->qos_work); 1765 1766 return 0; 1767 } 1768 1769 static int serial_omap_runtime_resume(struct device *dev) 1770 { 1771 struct uart_omap_port *up = dev_get_drvdata(dev); 1772 1773 int loss_cnt = serial_omap_get_context_loss_count(up); 1774 1775 serial_omap_enable_wakeup(up, false); 1776 1777 if (loss_cnt < 0) { 1778 dev_dbg(dev, "serial_omap_get_context_loss_count failed : %d\n", 1779 loss_cnt); 1780 serial_omap_restore_context(up); 1781 } else if (up->context_loss_cnt != loss_cnt) { 1782 serial_omap_restore_context(up); 1783 } 1784 up->latency = up->calc_latency; 1785 schedule_work(&up->qos_work); 1786 1787 return 0; 1788 } 1789 #endif 1790 1791 static const struct dev_pm_ops serial_omap_dev_pm_ops = { 1792 SET_SYSTEM_SLEEP_PM_OPS(serial_omap_suspend, serial_omap_resume) 1793 SET_RUNTIME_PM_OPS(serial_omap_runtime_suspend, 1794 serial_omap_runtime_resume, NULL) 1795 .prepare = serial_omap_prepare, 1796 .complete = serial_omap_complete, 1797 }; 1798 1799 #if defined(CONFIG_OF) 1800 static const struct of_device_id omap_serial_of_match[] = { 1801 { .compatible = "ti,omap2-uart" }, 1802 { .compatible = "ti,omap3-uart" }, 1803 { .compatible = "ti,omap4-uart" }, 1804 {}, 1805 }; 1806 MODULE_DEVICE_TABLE(of, omap_serial_of_match); 1807 #endif 1808 1809 static struct platform_driver serial_omap_driver = { 1810 .probe = serial_omap_probe, 1811 .remove = serial_omap_remove, 1812 .driver = { 1813 .name = OMAP_SERIAL_DRIVER_NAME, 1814 .pm = &serial_omap_dev_pm_ops, 1815 .of_match_table = of_match_ptr(omap_serial_of_match), 1816 }, 1817 }; 1818 1819 static int __init serial_omap_init(void) 1820 { 1821 int ret; 1822 1823 ret = uart_register_driver(&serial_omap_reg); 1824 if (ret != 0) 1825 return ret; 1826 ret = platform_driver_register(&serial_omap_driver); 1827 if (ret != 0) 1828 uart_unregister_driver(&serial_omap_reg); 1829 return ret; 1830 } 1831 1832 static void __exit serial_omap_exit(void) 1833 { 1834 platform_driver_unregister(&serial_omap_driver); 1835 uart_unregister_driver(&serial_omap_reg); 1836 } 1837 1838 module_init(serial_omap_init); 1839 module_exit(serial_omap_exit); 1840 1841 MODULE_DESCRIPTION("OMAP High Speed UART driver"); 1842 MODULE_LICENSE("GPL"); 1843 MODULE_AUTHOR("Texas Instruments Inc"); 1844