1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Driver for msm7k serial device and console 4 * 5 * Copyright (C) 2007 Google, Inc. 6 * Author: Robert Love <rlove@google.com> 7 * Copyright (c) 2011, Code Aurora Forum. All rights reserved. 8 */ 9 10 #if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) 11 # define SUPPORT_SYSRQ 12 #endif 13 14 #include <linux/kernel.h> 15 #include <linux/atomic.h> 16 #include <linux/dma-mapping.h> 17 #include <linux/dmaengine.h> 18 #include <linux/module.h> 19 #include <linux/io.h> 20 #include <linux/ioport.h> 21 #include <linux/interrupt.h> 22 #include <linux/init.h> 23 #include <linux/console.h> 24 #include <linux/tty.h> 25 #include <linux/tty_flip.h> 26 #include <linux/serial_core.h> 27 #include <linux/slab.h> 28 #include <linux/clk.h> 29 #include <linux/platform_device.h> 30 #include <linux/delay.h> 31 #include <linux/of.h> 32 #include <linux/of_device.h> 33 #include <linux/wait.h> 34 35 #define UART_MR1 0x0000 36 37 #define UART_MR1_AUTO_RFR_LEVEL0 0x3F 38 #define UART_MR1_AUTO_RFR_LEVEL1 0x3FF00 39 #define UART_DM_MR1_AUTO_RFR_LEVEL1 0xFFFFFF00 40 #define UART_MR1_RX_RDY_CTL BIT(7) 41 #define UART_MR1_CTS_CTL BIT(6) 42 43 #define UART_MR2 0x0004 44 #define UART_MR2_ERROR_MODE BIT(6) 45 #define UART_MR2_BITS_PER_CHAR 0x30 46 #define UART_MR2_BITS_PER_CHAR_5 (0x0 << 4) 47 #define UART_MR2_BITS_PER_CHAR_6 (0x1 << 4) 48 #define UART_MR2_BITS_PER_CHAR_7 (0x2 << 4) 49 #define UART_MR2_BITS_PER_CHAR_8 (0x3 << 4) 50 #define UART_MR2_STOP_BIT_LEN_ONE (0x1 << 2) 51 #define UART_MR2_STOP_BIT_LEN_TWO (0x3 << 2) 52 #define UART_MR2_PARITY_MODE_NONE 0x0 53 #define UART_MR2_PARITY_MODE_ODD 0x1 54 #define UART_MR2_PARITY_MODE_EVEN 0x2 55 #define UART_MR2_PARITY_MODE_SPACE 0x3 56 #define UART_MR2_PARITY_MODE 0x3 57 58 #define UART_CSR 0x0008 59 60 #define UART_TF 0x000C 61 #define UARTDM_TF 0x0070 62 63 #define UART_CR 0x0010 64 #define UART_CR_CMD_NULL (0 << 4) 65 #define UART_CR_CMD_RESET_RX (1 << 4) 66 #define UART_CR_CMD_RESET_TX (2 << 4) 67 #define UART_CR_CMD_RESET_ERR (3 << 4) 68 #define UART_CR_CMD_RESET_BREAK_INT (4 << 4) 69 #define UART_CR_CMD_START_BREAK (5 << 4) 70 #define UART_CR_CMD_STOP_BREAK (6 << 4) 71 #define UART_CR_CMD_RESET_CTS (7 << 4) 72 #define UART_CR_CMD_RESET_STALE_INT (8 << 4) 73 #define UART_CR_CMD_PACKET_MODE (9 << 4) 74 #define UART_CR_CMD_MODE_RESET (12 << 4) 75 #define UART_CR_CMD_SET_RFR (13 << 4) 76 #define UART_CR_CMD_RESET_RFR (14 << 4) 77 #define UART_CR_CMD_PROTECTION_EN (16 << 4) 78 #define UART_CR_CMD_STALE_EVENT_DISABLE (6 << 8) 79 #define UART_CR_CMD_STALE_EVENT_ENABLE (80 << 4) 80 #define UART_CR_CMD_FORCE_STALE (4 << 8) 81 #define UART_CR_CMD_RESET_TX_READY (3 << 8) 82 #define UART_CR_TX_DISABLE BIT(3) 83 #define UART_CR_TX_ENABLE BIT(2) 84 #define UART_CR_RX_DISABLE BIT(1) 85 #define UART_CR_RX_ENABLE BIT(0) 86 #define UART_CR_CMD_RESET_RXBREAK_START ((1 << 11) | (2 << 4)) 87 88 #define UART_IMR 0x0014 89 #define UART_IMR_TXLEV BIT(0) 90 #define UART_IMR_RXSTALE BIT(3) 91 #define UART_IMR_RXLEV BIT(4) 92 #define UART_IMR_DELTA_CTS BIT(5) 93 #define UART_IMR_CURRENT_CTS BIT(6) 94 #define UART_IMR_RXBREAK_START BIT(10) 95 96 #define UART_IPR_RXSTALE_LAST 0x20 97 #define UART_IPR_STALE_LSB 0x1F 98 #define UART_IPR_STALE_TIMEOUT_MSB 0x3FF80 99 #define UART_DM_IPR_STALE_TIMEOUT_MSB 0xFFFFFF80 100 101 #define UART_IPR 0x0018 102 #define UART_TFWR 0x001C 103 #define UART_RFWR 0x0020 104 #define UART_HCR 0x0024 105 106 #define UART_MREG 0x0028 107 #define UART_NREG 0x002C 108 #define UART_DREG 0x0030 109 #define UART_MNDREG 0x0034 110 #define UART_IRDA 0x0038 111 #define UART_MISR_MODE 0x0040 112 #define UART_MISR_RESET 0x0044 113 #define UART_MISR_EXPORT 0x0048 114 #define UART_MISR_VAL 0x004C 115 #define UART_TEST_CTRL 0x0050 116 117 #define UART_SR 0x0008 118 #define UART_SR_HUNT_CHAR BIT(7) 119 #define UART_SR_RX_BREAK BIT(6) 120 #define UART_SR_PAR_FRAME_ERR BIT(5) 121 #define UART_SR_OVERRUN BIT(4) 122 #define UART_SR_TX_EMPTY BIT(3) 123 #define UART_SR_TX_READY BIT(2) 124 #define UART_SR_RX_FULL BIT(1) 125 #define UART_SR_RX_READY BIT(0) 126 127 #define UART_RF 0x000C 128 #define UARTDM_RF 0x0070 129 #define UART_MISR 0x0010 130 #define UART_ISR 0x0014 131 #define UART_ISR_TX_READY BIT(7) 132 133 #define UARTDM_RXFS 0x50 134 #define UARTDM_RXFS_BUF_SHIFT 0x7 135 #define UARTDM_RXFS_BUF_MASK 0x7 136 137 #define UARTDM_DMEN 0x3C 138 #define UARTDM_DMEN_RX_SC_ENABLE BIT(5) 139 #define UARTDM_DMEN_TX_SC_ENABLE BIT(4) 140 141 #define UARTDM_DMEN_TX_BAM_ENABLE BIT(2) /* UARTDM_1P4 */ 142 #define UARTDM_DMEN_TX_DM_ENABLE BIT(0) /* < UARTDM_1P4 */ 143 144 #define UARTDM_DMEN_RX_BAM_ENABLE BIT(3) /* UARTDM_1P4 */ 145 #define UARTDM_DMEN_RX_DM_ENABLE BIT(1) /* < UARTDM_1P4 */ 146 147 #define UARTDM_DMRX 0x34 148 #define UARTDM_NCF_TX 0x40 149 #define UARTDM_RX_TOTAL_SNAP 0x38 150 151 #define UARTDM_BURST_SIZE 16 /* in bytes */ 152 #define UARTDM_TX_AIGN(x) ((x) & ~0x3) /* valid for > 1p3 */ 153 #define UARTDM_TX_MAX 256 /* in bytes, valid for <= 1p3 */ 154 #define UARTDM_RX_SIZE (UART_XMIT_SIZE / 4) 155 156 enum { 157 UARTDM_1P1 = 1, 158 UARTDM_1P2, 159 UARTDM_1P3, 160 UARTDM_1P4, 161 }; 162 163 struct msm_dma { 164 struct dma_chan *chan; 165 enum dma_data_direction dir; 166 dma_addr_t phys; 167 unsigned char *virt; 168 dma_cookie_t cookie; 169 u32 enable_bit; 170 unsigned int count; 171 struct dma_async_tx_descriptor *desc; 172 }; 173 174 struct msm_port { 175 struct uart_port uart; 176 char name[16]; 177 struct clk *clk; 178 struct clk *pclk; 179 unsigned int imr; 180 int is_uartdm; 181 unsigned int old_snap_state; 182 bool break_detected; 183 struct msm_dma tx_dma; 184 struct msm_dma rx_dma; 185 }; 186 187 #define UART_TO_MSM(uart_port) container_of(uart_port, struct msm_port, uart) 188 189 static 190 void msm_write(struct uart_port *port, unsigned int val, unsigned int off) 191 { 192 writel_relaxed(val, port->membase + off); 193 } 194 195 static 196 unsigned int msm_read(struct uart_port *port, unsigned int off) 197 { 198 return readl_relaxed(port->membase + off); 199 } 200 201 /* 202 * Setup the MND registers to use the TCXO clock. 203 */ 204 static void msm_serial_set_mnd_regs_tcxo(struct uart_port *port) 205 { 206 msm_write(port, 0x06, UART_MREG); 207 msm_write(port, 0xF1, UART_NREG); 208 msm_write(port, 0x0F, UART_DREG); 209 msm_write(port, 0x1A, UART_MNDREG); 210 port->uartclk = 1843200; 211 } 212 213 /* 214 * Setup the MND registers to use the TCXO clock divided by 4. 215 */ 216 static void msm_serial_set_mnd_regs_tcxoby4(struct uart_port *port) 217 { 218 msm_write(port, 0x18, UART_MREG); 219 msm_write(port, 0xF6, UART_NREG); 220 msm_write(port, 0x0F, UART_DREG); 221 msm_write(port, 0x0A, UART_MNDREG); 222 port->uartclk = 1843200; 223 } 224 225 static void msm_serial_set_mnd_regs(struct uart_port *port) 226 { 227 struct msm_port *msm_port = UART_TO_MSM(port); 228 229 /* 230 * These registers don't exist so we change the clk input rate 231 * on uartdm hardware instead 232 */ 233 if (msm_port->is_uartdm) 234 return; 235 236 if (port->uartclk == 19200000) 237 msm_serial_set_mnd_regs_tcxo(port); 238 else if (port->uartclk == 4800000) 239 msm_serial_set_mnd_regs_tcxoby4(port); 240 } 241 242 static void msm_handle_tx(struct uart_port *port); 243 static void msm_start_rx_dma(struct msm_port *msm_port); 244 245 static void msm_stop_dma(struct uart_port *port, struct msm_dma *dma) 246 { 247 struct device *dev = port->dev; 248 unsigned int mapped; 249 u32 val; 250 251 mapped = dma->count; 252 dma->count = 0; 253 254 dmaengine_terminate_all(dma->chan); 255 256 /* 257 * DMA Stall happens if enqueue and flush command happens concurrently. 258 * For example before changing the baud rate/protocol configuration and 259 * sending flush command to ADM, disable the channel of UARTDM. 260 * Note: should not reset the receiver here immediately as it is not 261 * suggested to do disable/reset or reset/disable at the same time. 262 */ 263 val = msm_read(port, UARTDM_DMEN); 264 val &= ~dma->enable_bit; 265 msm_write(port, val, UARTDM_DMEN); 266 267 if (mapped) 268 dma_unmap_single(dev, dma->phys, mapped, dma->dir); 269 } 270 271 static void msm_release_dma(struct msm_port *msm_port) 272 { 273 struct msm_dma *dma; 274 275 dma = &msm_port->tx_dma; 276 if (dma->chan) { 277 msm_stop_dma(&msm_port->uart, dma); 278 dma_release_channel(dma->chan); 279 } 280 281 memset(dma, 0, sizeof(*dma)); 282 283 dma = &msm_port->rx_dma; 284 if (dma->chan) { 285 msm_stop_dma(&msm_port->uart, dma); 286 dma_release_channel(dma->chan); 287 kfree(dma->virt); 288 } 289 290 memset(dma, 0, sizeof(*dma)); 291 } 292 293 static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base) 294 { 295 struct device *dev = msm_port->uart.dev; 296 struct dma_slave_config conf; 297 struct msm_dma *dma; 298 u32 crci = 0; 299 int ret; 300 301 dma = &msm_port->tx_dma; 302 303 /* allocate DMA resources, if available */ 304 dma->chan = dma_request_slave_channel_reason(dev, "tx"); 305 if (IS_ERR(dma->chan)) 306 goto no_tx; 307 308 of_property_read_u32(dev->of_node, "qcom,tx-crci", &crci); 309 310 memset(&conf, 0, sizeof(conf)); 311 conf.direction = DMA_MEM_TO_DEV; 312 conf.device_fc = true; 313 conf.dst_addr = base + UARTDM_TF; 314 conf.dst_maxburst = UARTDM_BURST_SIZE; 315 conf.slave_id = crci; 316 317 ret = dmaengine_slave_config(dma->chan, &conf); 318 if (ret) 319 goto rel_tx; 320 321 dma->dir = DMA_TO_DEVICE; 322 323 if (msm_port->is_uartdm < UARTDM_1P4) 324 dma->enable_bit = UARTDM_DMEN_TX_DM_ENABLE; 325 else 326 dma->enable_bit = UARTDM_DMEN_TX_BAM_ENABLE; 327 328 return; 329 330 rel_tx: 331 dma_release_channel(dma->chan); 332 no_tx: 333 memset(dma, 0, sizeof(*dma)); 334 } 335 336 static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base) 337 { 338 struct device *dev = msm_port->uart.dev; 339 struct dma_slave_config conf; 340 struct msm_dma *dma; 341 u32 crci = 0; 342 int ret; 343 344 dma = &msm_port->rx_dma; 345 346 /* allocate DMA resources, if available */ 347 dma->chan = dma_request_slave_channel_reason(dev, "rx"); 348 if (IS_ERR(dma->chan)) 349 goto no_rx; 350 351 of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci); 352 353 dma->virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL); 354 if (!dma->virt) 355 goto rel_rx; 356 357 memset(&conf, 0, sizeof(conf)); 358 conf.direction = DMA_DEV_TO_MEM; 359 conf.device_fc = true; 360 conf.src_addr = base + UARTDM_RF; 361 conf.src_maxburst = UARTDM_BURST_SIZE; 362 conf.slave_id = crci; 363 364 ret = dmaengine_slave_config(dma->chan, &conf); 365 if (ret) 366 goto err; 367 368 dma->dir = DMA_FROM_DEVICE; 369 370 if (msm_port->is_uartdm < UARTDM_1P4) 371 dma->enable_bit = UARTDM_DMEN_RX_DM_ENABLE; 372 else 373 dma->enable_bit = UARTDM_DMEN_RX_BAM_ENABLE; 374 375 return; 376 err: 377 kfree(dma->virt); 378 rel_rx: 379 dma_release_channel(dma->chan); 380 no_rx: 381 memset(dma, 0, sizeof(*dma)); 382 } 383 384 static inline void msm_wait_for_xmitr(struct uart_port *port) 385 { 386 while (!(msm_read(port, UART_SR) & UART_SR_TX_EMPTY)) { 387 if (msm_read(port, UART_ISR) & UART_ISR_TX_READY) 388 break; 389 udelay(1); 390 } 391 msm_write(port, UART_CR_CMD_RESET_TX_READY, UART_CR); 392 } 393 394 static void msm_stop_tx(struct uart_port *port) 395 { 396 struct msm_port *msm_port = UART_TO_MSM(port); 397 398 msm_port->imr &= ~UART_IMR_TXLEV; 399 msm_write(port, msm_port->imr, UART_IMR); 400 } 401 402 static void msm_start_tx(struct uart_port *port) 403 { 404 struct msm_port *msm_port = UART_TO_MSM(port); 405 struct msm_dma *dma = &msm_port->tx_dma; 406 407 /* Already started in DMA mode */ 408 if (dma->count) 409 return; 410 411 msm_port->imr |= UART_IMR_TXLEV; 412 msm_write(port, msm_port->imr, UART_IMR); 413 } 414 415 static void msm_reset_dm_count(struct uart_port *port, int count) 416 { 417 msm_wait_for_xmitr(port); 418 msm_write(port, count, UARTDM_NCF_TX); 419 msm_read(port, UARTDM_NCF_TX); 420 } 421 422 static void msm_complete_tx_dma(void *args) 423 { 424 struct msm_port *msm_port = args; 425 struct uart_port *port = &msm_port->uart; 426 struct circ_buf *xmit = &port->state->xmit; 427 struct msm_dma *dma = &msm_port->tx_dma; 428 struct dma_tx_state state; 429 enum dma_status status; 430 unsigned long flags; 431 unsigned int count; 432 u32 val; 433 434 spin_lock_irqsave(&port->lock, flags); 435 436 /* Already stopped */ 437 if (!dma->count) 438 goto done; 439 440 status = dmaengine_tx_status(dma->chan, dma->cookie, &state); 441 442 dma_unmap_single(port->dev, dma->phys, dma->count, dma->dir); 443 444 val = msm_read(port, UARTDM_DMEN); 445 val &= ~dma->enable_bit; 446 msm_write(port, val, UARTDM_DMEN); 447 448 if (msm_port->is_uartdm > UARTDM_1P3) { 449 msm_write(port, UART_CR_CMD_RESET_TX, UART_CR); 450 msm_write(port, UART_CR_TX_ENABLE, UART_CR); 451 } 452 453 count = dma->count - state.residue; 454 port->icount.tx += count; 455 dma->count = 0; 456 457 xmit->tail += count; 458 xmit->tail &= UART_XMIT_SIZE - 1; 459 460 /* Restore "Tx FIFO below watermark" interrupt */ 461 msm_port->imr |= UART_IMR_TXLEV; 462 msm_write(port, msm_port->imr, UART_IMR); 463 464 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 465 uart_write_wakeup(port); 466 467 msm_handle_tx(port); 468 done: 469 spin_unlock_irqrestore(&port->lock, flags); 470 } 471 472 static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count) 473 { 474 struct circ_buf *xmit = &msm_port->uart.state->xmit; 475 struct uart_port *port = &msm_port->uart; 476 struct msm_dma *dma = &msm_port->tx_dma; 477 void *cpu_addr; 478 int ret; 479 u32 val; 480 481 cpu_addr = &xmit->buf[xmit->tail]; 482 483 dma->phys = dma_map_single(port->dev, cpu_addr, count, dma->dir); 484 ret = dma_mapping_error(port->dev, dma->phys); 485 if (ret) 486 return ret; 487 488 dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, 489 count, DMA_MEM_TO_DEV, 490 DMA_PREP_INTERRUPT | 491 DMA_PREP_FENCE); 492 if (!dma->desc) { 493 ret = -EIO; 494 goto unmap; 495 } 496 497 dma->desc->callback = msm_complete_tx_dma; 498 dma->desc->callback_param = msm_port; 499 500 dma->cookie = dmaengine_submit(dma->desc); 501 ret = dma_submit_error(dma->cookie); 502 if (ret) 503 goto unmap; 504 505 /* 506 * Using DMA complete for Tx FIFO reload, no need for 507 * "Tx FIFO below watermark" one, disable it 508 */ 509 msm_port->imr &= ~UART_IMR_TXLEV; 510 msm_write(port, msm_port->imr, UART_IMR); 511 512 dma->count = count; 513 514 val = msm_read(port, UARTDM_DMEN); 515 val |= dma->enable_bit; 516 517 if (msm_port->is_uartdm < UARTDM_1P4) 518 msm_write(port, val, UARTDM_DMEN); 519 520 msm_reset_dm_count(port, count); 521 522 if (msm_port->is_uartdm > UARTDM_1P3) 523 msm_write(port, val, UARTDM_DMEN); 524 525 dma_async_issue_pending(dma->chan); 526 return 0; 527 unmap: 528 dma_unmap_single(port->dev, dma->phys, count, dma->dir); 529 return ret; 530 } 531 532 static void msm_complete_rx_dma(void *args) 533 { 534 struct msm_port *msm_port = args; 535 struct uart_port *port = &msm_port->uart; 536 struct tty_port *tport = &port->state->port; 537 struct msm_dma *dma = &msm_port->rx_dma; 538 int count = 0, i, sysrq; 539 unsigned long flags; 540 u32 val; 541 542 spin_lock_irqsave(&port->lock, flags); 543 544 /* Already stopped */ 545 if (!dma->count) 546 goto done; 547 548 val = msm_read(port, UARTDM_DMEN); 549 val &= ~dma->enable_bit; 550 msm_write(port, val, UARTDM_DMEN); 551 552 if (msm_read(port, UART_SR) & UART_SR_OVERRUN) { 553 port->icount.overrun++; 554 tty_insert_flip_char(tport, 0, TTY_OVERRUN); 555 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR); 556 } 557 558 count = msm_read(port, UARTDM_RX_TOTAL_SNAP); 559 560 port->icount.rx += count; 561 562 dma->count = 0; 563 564 dma_unmap_single(port->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); 565 566 for (i = 0; i < count; i++) { 567 char flag = TTY_NORMAL; 568 569 if (msm_port->break_detected && dma->virt[i] == 0) { 570 port->icount.brk++; 571 flag = TTY_BREAK; 572 msm_port->break_detected = false; 573 if (uart_handle_break(port)) 574 continue; 575 } 576 577 if (!(port->read_status_mask & UART_SR_RX_BREAK)) 578 flag = TTY_NORMAL; 579 580 spin_unlock_irqrestore(&port->lock, flags); 581 sysrq = uart_handle_sysrq_char(port, dma->virt[i]); 582 spin_lock_irqsave(&port->lock, flags); 583 if (!sysrq) 584 tty_insert_flip_char(tport, dma->virt[i], flag); 585 } 586 587 msm_start_rx_dma(msm_port); 588 done: 589 spin_unlock_irqrestore(&port->lock, flags); 590 591 if (count) 592 tty_flip_buffer_push(tport); 593 } 594 595 static void msm_start_rx_dma(struct msm_port *msm_port) 596 { 597 struct msm_dma *dma = &msm_port->rx_dma; 598 struct uart_port *uart = &msm_port->uart; 599 u32 val; 600 int ret; 601 602 if (!dma->chan) 603 return; 604 605 dma->phys = dma_map_single(uart->dev, dma->virt, 606 UARTDM_RX_SIZE, dma->dir); 607 ret = dma_mapping_error(uart->dev, dma->phys); 608 if (ret) 609 return; 610 611 dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, 612 UARTDM_RX_SIZE, DMA_DEV_TO_MEM, 613 DMA_PREP_INTERRUPT); 614 if (!dma->desc) 615 goto unmap; 616 617 dma->desc->callback = msm_complete_rx_dma; 618 dma->desc->callback_param = msm_port; 619 620 dma->cookie = dmaengine_submit(dma->desc); 621 ret = dma_submit_error(dma->cookie); 622 if (ret) 623 goto unmap; 624 /* 625 * Using DMA for FIFO off-load, no need for "Rx FIFO over 626 * watermark" or "stale" interrupts, disable them 627 */ 628 msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE); 629 630 /* 631 * Well, when DMA is ADM3 engine(implied by <= UARTDM v1.3), 632 * we need RXSTALE to flush input DMA fifo to memory 633 */ 634 if (msm_port->is_uartdm < UARTDM_1P4) 635 msm_port->imr |= UART_IMR_RXSTALE; 636 637 msm_write(uart, msm_port->imr, UART_IMR); 638 639 dma->count = UARTDM_RX_SIZE; 640 641 dma_async_issue_pending(dma->chan); 642 643 msm_write(uart, UART_CR_CMD_RESET_STALE_INT, UART_CR); 644 msm_write(uart, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR); 645 646 val = msm_read(uart, UARTDM_DMEN); 647 val |= dma->enable_bit; 648 649 if (msm_port->is_uartdm < UARTDM_1P4) 650 msm_write(uart, val, UARTDM_DMEN); 651 652 msm_write(uart, UARTDM_RX_SIZE, UARTDM_DMRX); 653 654 if (msm_port->is_uartdm > UARTDM_1P3) 655 msm_write(uart, val, UARTDM_DMEN); 656 657 return; 658 unmap: 659 dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); 660 } 661 662 static void msm_stop_rx(struct uart_port *port) 663 { 664 struct msm_port *msm_port = UART_TO_MSM(port); 665 struct msm_dma *dma = &msm_port->rx_dma; 666 667 msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE); 668 msm_write(port, msm_port->imr, UART_IMR); 669 670 if (dma->chan) 671 msm_stop_dma(port, dma); 672 } 673 674 static void msm_enable_ms(struct uart_port *port) 675 { 676 struct msm_port *msm_port = UART_TO_MSM(port); 677 678 msm_port->imr |= UART_IMR_DELTA_CTS; 679 msm_write(port, msm_port->imr, UART_IMR); 680 } 681 682 static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr) 683 { 684 struct tty_port *tport = &port->state->port; 685 unsigned int sr; 686 int count = 0; 687 struct msm_port *msm_port = UART_TO_MSM(port); 688 689 if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) { 690 port->icount.overrun++; 691 tty_insert_flip_char(tport, 0, TTY_OVERRUN); 692 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR); 693 } 694 695 if (misr & UART_IMR_RXSTALE) { 696 count = msm_read(port, UARTDM_RX_TOTAL_SNAP) - 697 msm_port->old_snap_state; 698 msm_port->old_snap_state = 0; 699 } else { 700 count = 4 * (msm_read(port, UART_RFWR)); 701 msm_port->old_snap_state += count; 702 } 703 704 /* TODO: Precise error reporting */ 705 706 port->icount.rx += count; 707 708 while (count > 0) { 709 unsigned char buf[4]; 710 int sysrq, r_count, i; 711 712 sr = msm_read(port, UART_SR); 713 if ((sr & UART_SR_RX_READY) == 0) { 714 msm_port->old_snap_state -= count; 715 break; 716 } 717 718 ioread32_rep(port->membase + UARTDM_RF, buf, 1); 719 r_count = min_t(int, count, sizeof(buf)); 720 721 for (i = 0; i < r_count; i++) { 722 char flag = TTY_NORMAL; 723 724 if (msm_port->break_detected && buf[i] == 0) { 725 port->icount.brk++; 726 flag = TTY_BREAK; 727 msm_port->break_detected = false; 728 if (uart_handle_break(port)) 729 continue; 730 } 731 732 if (!(port->read_status_mask & UART_SR_RX_BREAK)) 733 flag = TTY_NORMAL; 734 735 spin_unlock(&port->lock); 736 sysrq = uart_handle_sysrq_char(port, buf[i]); 737 spin_lock(&port->lock); 738 if (!sysrq) 739 tty_insert_flip_char(tport, buf[i], flag); 740 } 741 count -= r_count; 742 } 743 744 spin_unlock(&port->lock); 745 tty_flip_buffer_push(tport); 746 spin_lock(&port->lock); 747 748 if (misr & (UART_IMR_RXSTALE)) 749 msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR); 750 msm_write(port, 0xFFFFFF, UARTDM_DMRX); 751 msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR); 752 753 /* Try to use DMA */ 754 msm_start_rx_dma(msm_port); 755 } 756 757 static void msm_handle_rx(struct uart_port *port) 758 { 759 struct tty_port *tport = &port->state->port; 760 unsigned int sr; 761 762 /* 763 * Handle overrun. My understanding of the hardware is that overrun 764 * is not tied to the RX buffer, so we handle the case out of band. 765 */ 766 if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) { 767 port->icount.overrun++; 768 tty_insert_flip_char(tport, 0, TTY_OVERRUN); 769 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR); 770 } 771 772 /* and now the main RX loop */ 773 while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) { 774 unsigned int c; 775 char flag = TTY_NORMAL; 776 int sysrq; 777 778 c = msm_read(port, UART_RF); 779 780 if (sr & UART_SR_RX_BREAK) { 781 port->icount.brk++; 782 if (uart_handle_break(port)) 783 continue; 784 } else if (sr & UART_SR_PAR_FRAME_ERR) { 785 port->icount.frame++; 786 } else { 787 port->icount.rx++; 788 } 789 790 /* Mask conditions we're ignorning. */ 791 sr &= port->read_status_mask; 792 793 if (sr & UART_SR_RX_BREAK) 794 flag = TTY_BREAK; 795 else if (sr & UART_SR_PAR_FRAME_ERR) 796 flag = TTY_FRAME; 797 798 spin_unlock(&port->lock); 799 sysrq = uart_handle_sysrq_char(port, c); 800 spin_lock(&port->lock); 801 if (!sysrq) 802 tty_insert_flip_char(tport, c, flag); 803 } 804 805 spin_unlock(&port->lock); 806 tty_flip_buffer_push(tport); 807 spin_lock(&port->lock); 808 } 809 810 static void msm_handle_tx_pio(struct uart_port *port, unsigned int tx_count) 811 { 812 struct circ_buf *xmit = &port->state->xmit; 813 struct msm_port *msm_port = UART_TO_MSM(port); 814 unsigned int num_chars; 815 unsigned int tf_pointer = 0; 816 void __iomem *tf; 817 818 if (msm_port->is_uartdm) 819 tf = port->membase + UARTDM_TF; 820 else 821 tf = port->membase + UART_TF; 822 823 if (tx_count && msm_port->is_uartdm) 824 msm_reset_dm_count(port, tx_count); 825 826 while (tf_pointer < tx_count) { 827 int i; 828 char buf[4] = { 0 }; 829 830 if (!(msm_read(port, UART_SR) & UART_SR_TX_READY)) 831 break; 832 833 if (msm_port->is_uartdm) 834 num_chars = min(tx_count - tf_pointer, 835 (unsigned int)sizeof(buf)); 836 else 837 num_chars = 1; 838 839 for (i = 0; i < num_chars; i++) { 840 buf[i] = xmit->buf[xmit->tail + i]; 841 port->icount.tx++; 842 } 843 844 iowrite32_rep(tf, buf, 1); 845 xmit->tail = (xmit->tail + num_chars) & (UART_XMIT_SIZE - 1); 846 tf_pointer += num_chars; 847 } 848 849 /* disable tx interrupts if nothing more to send */ 850 if (uart_circ_empty(xmit)) 851 msm_stop_tx(port); 852 853 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 854 uart_write_wakeup(port); 855 } 856 857 static void msm_handle_tx(struct uart_port *port) 858 { 859 struct msm_port *msm_port = UART_TO_MSM(port); 860 struct circ_buf *xmit = &msm_port->uart.state->xmit; 861 struct msm_dma *dma = &msm_port->tx_dma; 862 unsigned int pio_count, dma_count, dma_min; 863 void __iomem *tf; 864 int err = 0; 865 866 if (port->x_char) { 867 if (msm_port->is_uartdm) 868 tf = port->membase + UARTDM_TF; 869 else 870 tf = port->membase + UART_TF; 871 872 if (msm_port->is_uartdm) 873 msm_reset_dm_count(port, 1); 874 875 iowrite8_rep(tf, &port->x_char, 1); 876 port->icount.tx++; 877 port->x_char = 0; 878 return; 879 } 880 881 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { 882 msm_stop_tx(port); 883 return; 884 } 885 886 pio_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); 887 dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); 888 889 dma_min = 1; /* Always DMA */ 890 if (msm_port->is_uartdm > UARTDM_1P3) { 891 dma_count = UARTDM_TX_AIGN(dma_count); 892 dma_min = UARTDM_BURST_SIZE; 893 } else { 894 if (dma_count > UARTDM_TX_MAX) 895 dma_count = UARTDM_TX_MAX; 896 } 897 898 if (pio_count > port->fifosize) 899 pio_count = port->fifosize; 900 901 if (!dma->chan || dma_count < dma_min) 902 msm_handle_tx_pio(port, pio_count); 903 else 904 err = msm_handle_tx_dma(msm_port, dma_count); 905 906 if (err) /* fall back to PIO mode */ 907 msm_handle_tx_pio(port, pio_count); 908 } 909 910 static void msm_handle_delta_cts(struct uart_port *port) 911 { 912 msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR); 913 port->icount.cts++; 914 wake_up_interruptible(&port->state->port.delta_msr_wait); 915 } 916 917 static irqreturn_t msm_uart_irq(int irq, void *dev_id) 918 { 919 struct uart_port *port = dev_id; 920 struct msm_port *msm_port = UART_TO_MSM(port); 921 struct msm_dma *dma = &msm_port->rx_dma; 922 unsigned long flags; 923 unsigned int misr; 924 u32 val; 925 926 spin_lock_irqsave(&port->lock, flags); 927 misr = msm_read(port, UART_MISR); 928 msm_write(port, 0, UART_IMR); /* disable interrupt */ 929 930 if (misr & UART_IMR_RXBREAK_START) { 931 msm_port->break_detected = true; 932 msm_write(port, UART_CR_CMD_RESET_RXBREAK_START, UART_CR); 933 } 934 935 if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE)) { 936 if (dma->count) { 937 val = UART_CR_CMD_STALE_EVENT_DISABLE; 938 msm_write(port, val, UART_CR); 939 val = UART_CR_CMD_RESET_STALE_INT; 940 msm_write(port, val, UART_CR); 941 /* 942 * Flush DMA input fifo to memory, this will also 943 * trigger DMA RX completion 944 */ 945 dmaengine_terminate_all(dma->chan); 946 } else if (msm_port->is_uartdm) { 947 msm_handle_rx_dm(port, misr); 948 } else { 949 msm_handle_rx(port); 950 } 951 } 952 if (misr & UART_IMR_TXLEV) 953 msm_handle_tx(port); 954 if (misr & UART_IMR_DELTA_CTS) 955 msm_handle_delta_cts(port); 956 957 msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */ 958 spin_unlock_irqrestore(&port->lock, flags); 959 960 return IRQ_HANDLED; 961 } 962 963 static unsigned int msm_tx_empty(struct uart_port *port) 964 { 965 return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0; 966 } 967 968 static unsigned int msm_get_mctrl(struct uart_port *port) 969 { 970 return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS; 971 } 972 973 static void msm_reset(struct uart_port *port) 974 { 975 struct msm_port *msm_port = UART_TO_MSM(port); 976 977 /* reset everything */ 978 msm_write(port, UART_CR_CMD_RESET_RX, UART_CR); 979 msm_write(port, UART_CR_CMD_RESET_TX, UART_CR); 980 msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR); 981 msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR); 982 msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR); 983 msm_write(port, UART_CR_CMD_SET_RFR, UART_CR); 984 985 /* Disable DM modes */ 986 if (msm_port->is_uartdm) 987 msm_write(port, 0, UARTDM_DMEN); 988 } 989 990 static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl) 991 { 992 unsigned int mr; 993 994 mr = msm_read(port, UART_MR1); 995 996 if (!(mctrl & TIOCM_RTS)) { 997 mr &= ~UART_MR1_RX_RDY_CTL; 998 msm_write(port, mr, UART_MR1); 999 msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR); 1000 } else { 1001 mr |= UART_MR1_RX_RDY_CTL; 1002 msm_write(port, mr, UART_MR1); 1003 } 1004 } 1005 1006 static void msm_break_ctl(struct uart_port *port, int break_ctl) 1007 { 1008 if (break_ctl) 1009 msm_write(port, UART_CR_CMD_START_BREAK, UART_CR); 1010 else 1011 msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR); 1012 } 1013 1014 struct msm_baud_map { 1015 u16 divisor; 1016 u8 code; 1017 u8 rxstale; 1018 }; 1019 1020 static const struct msm_baud_map * 1021 msm_find_best_baud(struct uart_port *port, unsigned int baud, 1022 unsigned long *rate) 1023 { 1024 struct msm_port *msm_port = UART_TO_MSM(port); 1025 unsigned int divisor, result; 1026 unsigned long target, old, best_rate = 0, diff, best_diff = ULONG_MAX; 1027 const struct msm_baud_map *entry, *end, *best; 1028 static const struct msm_baud_map table[] = { 1029 { 1, 0xff, 31 }, 1030 { 2, 0xee, 16 }, 1031 { 3, 0xdd, 8 }, 1032 { 4, 0xcc, 6 }, 1033 { 6, 0xbb, 6 }, 1034 { 8, 0xaa, 6 }, 1035 { 12, 0x99, 6 }, 1036 { 16, 0x88, 1 }, 1037 { 24, 0x77, 1 }, 1038 { 32, 0x66, 1 }, 1039 { 48, 0x55, 1 }, 1040 { 96, 0x44, 1 }, 1041 { 192, 0x33, 1 }, 1042 { 384, 0x22, 1 }, 1043 { 768, 0x11, 1 }, 1044 { 1536, 0x00, 1 }, 1045 }; 1046 1047 best = table; /* Default to smallest divider */ 1048 target = clk_round_rate(msm_port->clk, 16 * baud); 1049 divisor = DIV_ROUND_CLOSEST(target, 16 * baud); 1050 1051 end = table + ARRAY_SIZE(table); 1052 entry = table; 1053 while (entry < end) { 1054 if (entry->divisor <= divisor) { 1055 result = target / entry->divisor / 16; 1056 diff = abs(result - baud); 1057 1058 /* Keep track of best entry */ 1059 if (diff < best_diff) { 1060 best_diff = diff; 1061 best = entry; 1062 best_rate = target; 1063 } 1064 1065 if (result == baud) 1066 break; 1067 } else if (entry->divisor > divisor) { 1068 old = target; 1069 target = clk_round_rate(msm_port->clk, old + 1); 1070 /* 1071 * The rate didn't get any faster so we can't do 1072 * better at dividing it down 1073 */ 1074 if (target == old) 1075 break; 1076 1077 /* Start the divisor search over at this new rate */ 1078 entry = table; 1079 divisor = DIV_ROUND_CLOSEST(target, 16 * baud); 1080 continue; 1081 } 1082 entry++; 1083 } 1084 1085 *rate = best_rate; 1086 return best; 1087 } 1088 1089 static int msm_set_baud_rate(struct uart_port *port, unsigned int baud, 1090 unsigned long *saved_flags) 1091 { 1092 unsigned int rxstale, watermark, mask; 1093 struct msm_port *msm_port = UART_TO_MSM(port); 1094 const struct msm_baud_map *entry; 1095 unsigned long flags, rate; 1096 1097 flags = *saved_flags; 1098 spin_unlock_irqrestore(&port->lock, flags); 1099 1100 entry = msm_find_best_baud(port, baud, &rate); 1101 clk_set_rate(msm_port->clk, rate); 1102 baud = rate / 16 / entry->divisor; 1103 1104 spin_lock_irqsave(&port->lock, flags); 1105 *saved_flags = flags; 1106 port->uartclk = rate; 1107 1108 msm_write(port, entry->code, UART_CSR); 1109 1110 /* RX stale watermark */ 1111 rxstale = entry->rxstale; 1112 watermark = UART_IPR_STALE_LSB & rxstale; 1113 if (msm_port->is_uartdm) { 1114 mask = UART_DM_IPR_STALE_TIMEOUT_MSB; 1115 } else { 1116 watermark |= UART_IPR_RXSTALE_LAST; 1117 mask = UART_IPR_STALE_TIMEOUT_MSB; 1118 } 1119 1120 watermark |= mask & (rxstale << 2); 1121 1122 msm_write(port, watermark, UART_IPR); 1123 1124 /* set RX watermark */ 1125 watermark = (port->fifosize * 3) / 4; 1126 msm_write(port, watermark, UART_RFWR); 1127 1128 /* set TX watermark */ 1129 msm_write(port, 10, UART_TFWR); 1130 1131 msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR); 1132 msm_reset(port); 1133 1134 /* Enable RX and TX */ 1135 msm_write(port, UART_CR_TX_ENABLE | UART_CR_RX_ENABLE, UART_CR); 1136 1137 /* turn on RX and CTS interrupts */ 1138 msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE | 1139 UART_IMR_CURRENT_CTS | UART_IMR_RXBREAK_START; 1140 1141 msm_write(port, msm_port->imr, UART_IMR); 1142 1143 if (msm_port->is_uartdm) { 1144 msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR); 1145 msm_write(port, 0xFFFFFF, UARTDM_DMRX); 1146 msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR); 1147 } 1148 1149 return baud; 1150 } 1151 1152 static void msm_init_clock(struct uart_port *port) 1153 { 1154 struct msm_port *msm_port = UART_TO_MSM(port); 1155 1156 clk_prepare_enable(msm_port->clk); 1157 clk_prepare_enable(msm_port->pclk); 1158 msm_serial_set_mnd_regs(port); 1159 } 1160 1161 static int msm_startup(struct uart_port *port) 1162 { 1163 struct msm_port *msm_port = UART_TO_MSM(port); 1164 unsigned int data, rfr_level, mask; 1165 int ret; 1166 1167 snprintf(msm_port->name, sizeof(msm_port->name), 1168 "msm_serial%d", port->line); 1169 1170 msm_init_clock(port); 1171 1172 if (likely(port->fifosize > 12)) 1173 rfr_level = port->fifosize - 12; 1174 else 1175 rfr_level = port->fifosize; 1176 1177 /* set automatic RFR level */ 1178 data = msm_read(port, UART_MR1); 1179 1180 if (msm_port->is_uartdm) 1181 mask = UART_DM_MR1_AUTO_RFR_LEVEL1; 1182 else 1183 mask = UART_MR1_AUTO_RFR_LEVEL1; 1184 1185 data &= ~mask; 1186 data &= ~UART_MR1_AUTO_RFR_LEVEL0; 1187 data |= mask & (rfr_level << 2); 1188 data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level; 1189 msm_write(port, data, UART_MR1); 1190 1191 if (msm_port->is_uartdm) { 1192 msm_request_tx_dma(msm_port, msm_port->uart.mapbase); 1193 msm_request_rx_dma(msm_port, msm_port->uart.mapbase); 1194 } 1195 1196 ret = request_irq(port->irq, msm_uart_irq, IRQF_TRIGGER_HIGH, 1197 msm_port->name, port); 1198 if (unlikely(ret)) 1199 goto err_irq; 1200 1201 return 0; 1202 1203 err_irq: 1204 if (msm_port->is_uartdm) 1205 msm_release_dma(msm_port); 1206 1207 clk_disable_unprepare(msm_port->pclk); 1208 clk_disable_unprepare(msm_port->clk); 1209 1210 return ret; 1211 } 1212 1213 static void msm_shutdown(struct uart_port *port) 1214 { 1215 struct msm_port *msm_port = UART_TO_MSM(port); 1216 1217 msm_port->imr = 0; 1218 msm_write(port, 0, UART_IMR); /* disable interrupts */ 1219 1220 if (msm_port->is_uartdm) 1221 msm_release_dma(msm_port); 1222 1223 clk_disable_unprepare(msm_port->clk); 1224 1225 free_irq(port->irq, port); 1226 } 1227 1228 static void msm_set_termios(struct uart_port *port, struct ktermios *termios, 1229 struct ktermios *old) 1230 { 1231 struct msm_port *msm_port = UART_TO_MSM(port); 1232 struct msm_dma *dma = &msm_port->rx_dma; 1233 unsigned long flags; 1234 unsigned int baud, mr; 1235 1236 spin_lock_irqsave(&port->lock, flags); 1237 1238 if (dma->chan) /* Terminate if any */ 1239 msm_stop_dma(port, dma); 1240 1241 /* calculate and set baud rate */ 1242 baud = uart_get_baud_rate(port, termios, old, 300, 4000000); 1243 baud = msm_set_baud_rate(port, baud, &flags); 1244 if (tty_termios_baud_rate(termios)) 1245 tty_termios_encode_baud_rate(termios, baud, baud); 1246 1247 /* calculate parity */ 1248 mr = msm_read(port, UART_MR2); 1249 mr &= ~UART_MR2_PARITY_MODE; 1250 if (termios->c_cflag & PARENB) { 1251 if (termios->c_cflag & PARODD) 1252 mr |= UART_MR2_PARITY_MODE_ODD; 1253 else if (termios->c_cflag & CMSPAR) 1254 mr |= UART_MR2_PARITY_MODE_SPACE; 1255 else 1256 mr |= UART_MR2_PARITY_MODE_EVEN; 1257 } 1258 1259 /* calculate bits per char */ 1260 mr &= ~UART_MR2_BITS_PER_CHAR; 1261 switch (termios->c_cflag & CSIZE) { 1262 case CS5: 1263 mr |= UART_MR2_BITS_PER_CHAR_5; 1264 break; 1265 case CS6: 1266 mr |= UART_MR2_BITS_PER_CHAR_6; 1267 break; 1268 case CS7: 1269 mr |= UART_MR2_BITS_PER_CHAR_7; 1270 break; 1271 case CS8: 1272 default: 1273 mr |= UART_MR2_BITS_PER_CHAR_8; 1274 break; 1275 } 1276 1277 /* calculate stop bits */ 1278 mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO); 1279 if (termios->c_cflag & CSTOPB) 1280 mr |= UART_MR2_STOP_BIT_LEN_TWO; 1281 else 1282 mr |= UART_MR2_STOP_BIT_LEN_ONE; 1283 1284 /* set parity, bits per char, and stop bit */ 1285 msm_write(port, mr, UART_MR2); 1286 1287 /* calculate and set hardware flow control */ 1288 mr = msm_read(port, UART_MR1); 1289 mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL); 1290 if (termios->c_cflag & CRTSCTS) { 1291 mr |= UART_MR1_CTS_CTL; 1292 mr |= UART_MR1_RX_RDY_CTL; 1293 } 1294 msm_write(port, mr, UART_MR1); 1295 1296 /* Configure status bits to ignore based on termio flags. */ 1297 port->read_status_mask = 0; 1298 if (termios->c_iflag & INPCK) 1299 port->read_status_mask |= UART_SR_PAR_FRAME_ERR; 1300 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) 1301 port->read_status_mask |= UART_SR_RX_BREAK; 1302 1303 uart_update_timeout(port, termios->c_cflag, baud); 1304 1305 /* Try to use DMA */ 1306 msm_start_rx_dma(msm_port); 1307 1308 spin_unlock_irqrestore(&port->lock, flags); 1309 } 1310 1311 static const char *msm_type(struct uart_port *port) 1312 { 1313 return "MSM"; 1314 } 1315 1316 static void msm_release_port(struct uart_port *port) 1317 { 1318 struct platform_device *pdev = to_platform_device(port->dev); 1319 struct resource *uart_resource; 1320 resource_size_t size; 1321 1322 uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1323 if (unlikely(!uart_resource)) 1324 return; 1325 size = resource_size(uart_resource); 1326 1327 release_mem_region(port->mapbase, size); 1328 iounmap(port->membase); 1329 port->membase = NULL; 1330 } 1331 1332 static int msm_request_port(struct uart_port *port) 1333 { 1334 struct platform_device *pdev = to_platform_device(port->dev); 1335 struct resource *uart_resource; 1336 resource_size_t size; 1337 int ret; 1338 1339 uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1340 if (unlikely(!uart_resource)) 1341 return -ENXIO; 1342 1343 size = resource_size(uart_resource); 1344 1345 if (!request_mem_region(port->mapbase, size, "msm_serial")) 1346 return -EBUSY; 1347 1348 port->membase = ioremap(port->mapbase, size); 1349 if (!port->membase) { 1350 ret = -EBUSY; 1351 goto fail_release_port; 1352 } 1353 1354 return 0; 1355 1356 fail_release_port: 1357 release_mem_region(port->mapbase, size); 1358 return ret; 1359 } 1360 1361 static void msm_config_port(struct uart_port *port, int flags) 1362 { 1363 int ret; 1364 1365 if (flags & UART_CONFIG_TYPE) { 1366 port->type = PORT_MSM; 1367 ret = msm_request_port(port); 1368 if (ret) 1369 return; 1370 } 1371 } 1372 1373 static int msm_verify_port(struct uart_port *port, struct serial_struct *ser) 1374 { 1375 if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM)) 1376 return -EINVAL; 1377 if (unlikely(port->irq != ser->irq)) 1378 return -EINVAL; 1379 return 0; 1380 } 1381 1382 static void msm_power(struct uart_port *port, unsigned int state, 1383 unsigned int oldstate) 1384 { 1385 struct msm_port *msm_port = UART_TO_MSM(port); 1386 1387 switch (state) { 1388 case 0: 1389 clk_prepare_enable(msm_port->clk); 1390 clk_prepare_enable(msm_port->pclk); 1391 break; 1392 case 3: 1393 clk_disable_unprepare(msm_port->clk); 1394 clk_disable_unprepare(msm_port->pclk); 1395 break; 1396 default: 1397 pr_err("msm_serial: Unknown PM state %d\n", state); 1398 } 1399 } 1400 1401 #ifdef CONFIG_CONSOLE_POLL 1402 static int msm_poll_get_char_single(struct uart_port *port) 1403 { 1404 struct msm_port *msm_port = UART_TO_MSM(port); 1405 unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : UART_RF; 1406 1407 if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) 1408 return NO_POLL_CHAR; 1409 1410 return msm_read(port, rf_reg) & 0xff; 1411 } 1412 1413 static int msm_poll_get_char_dm(struct uart_port *port) 1414 { 1415 int c; 1416 static u32 slop; 1417 static int count; 1418 unsigned char *sp = (unsigned char *)&slop; 1419 1420 /* Check if a previous read had more than one char */ 1421 if (count) { 1422 c = sp[sizeof(slop) - count]; 1423 count--; 1424 /* Or if FIFO is empty */ 1425 } else if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) { 1426 /* 1427 * If RX packing buffer has less than a word, force stale to 1428 * push contents into RX FIFO 1429 */ 1430 count = msm_read(port, UARTDM_RXFS); 1431 count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK; 1432 if (count) { 1433 msm_write(port, UART_CR_CMD_FORCE_STALE, UART_CR); 1434 slop = msm_read(port, UARTDM_RF); 1435 c = sp[0]; 1436 count--; 1437 msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR); 1438 msm_write(port, 0xFFFFFF, UARTDM_DMRX); 1439 msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, 1440 UART_CR); 1441 } else { 1442 c = NO_POLL_CHAR; 1443 } 1444 /* FIFO has a word */ 1445 } else { 1446 slop = msm_read(port, UARTDM_RF); 1447 c = sp[0]; 1448 count = sizeof(slop) - 1; 1449 } 1450 1451 return c; 1452 } 1453 1454 static int msm_poll_get_char(struct uart_port *port) 1455 { 1456 u32 imr; 1457 int c; 1458 struct msm_port *msm_port = UART_TO_MSM(port); 1459 1460 /* Disable all interrupts */ 1461 imr = msm_read(port, UART_IMR); 1462 msm_write(port, 0, UART_IMR); 1463 1464 if (msm_port->is_uartdm) 1465 c = msm_poll_get_char_dm(port); 1466 else 1467 c = msm_poll_get_char_single(port); 1468 1469 /* Enable interrupts */ 1470 msm_write(port, imr, UART_IMR); 1471 1472 return c; 1473 } 1474 1475 static void msm_poll_put_char(struct uart_port *port, unsigned char c) 1476 { 1477 u32 imr; 1478 struct msm_port *msm_port = UART_TO_MSM(port); 1479 1480 /* Disable all interrupts */ 1481 imr = msm_read(port, UART_IMR); 1482 msm_write(port, 0, UART_IMR); 1483 1484 if (msm_port->is_uartdm) 1485 msm_reset_dm_count(port, 1); 1486 1487 /* Wait until FIFO is empty */ 1488 while (!(msm_read(port, UART_SR) & UART_SR_TX_READY)) 1489 cpu_relax(); 1490 1491 /* Write a character */ 1492 msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : UART_TF); 1493 1494 /* Wait until FIFO is empty */ 1495 while (!(msm_read(port, UART_SR) & UART_SR_TX_READY)) 1496 cpu_relax(); 1497 1498 /* Enable interrupts */ 1499 msm_write(port, imr, UART_IMR); 1500 } 1501 #endif 1502 1503 static struct uart_ops msm_uart_pops = { 1504 .tx_empty = msm_tx_empty, 1505 .set_mctrl = msm_set_mctrl, 1506 .get_mctrl = msm_get_mctrl, 1507 .stop_tx = msm_stop_tx, 1508 .start_tx = msm_start_tx, 1509 .stop_rx = msm_stop_rx, 1510 .enable_ms = msm_enable_ms, 1511 .break_ctl = msm_break_ctl, 1512 .startup = msm_startup, 1513 .shutdown = msm_shutdown, 1514 .set_termios = msm_set_termios, 1515 .type = msm_type, 1516 .release_port = msm_release_port, 1517 .request_port = msm_request_port, 1518 .config_port = msm_config_port, 1519 .verify_port = msm_verify_port, 1520 .pm = msm_power, 1521 #ifdef CONFIG_CONSOLE_POLL 1522 .poll_get_char = msm_poll_get_char, 1523 .poll_put_char = msm_poll_put_char, 1524 #endif 1525 }; 1526 1527 static struct msm_port msm_uart_ports[] = { 1528 { 1529 .uart = { 1530 .iotype = UPIO_MEM, 1531 .ops = &msm_uart_pops, 1532 .flags = UPF_BOOT_AUTOCONF, 1533 .fifosize = 64, 1534 .line = 0, 1535 }, 1536 }, 1537 { 1538 .uart = { 1539 .iotype = UPIO_MEM, 1540 .ops = &msm_uart_pops, 1541 .flags = UPF_BOOT_AUTOCONF, 1542 .fifosize = 64, 1543 .line = 1, 1544 }, 1545 }, 1546 { 1547 .uart = { 1548 .iotype = UPIO_MEM, 1549 .ops = &msm_uart_pops, 1550 .flags = UPF_BOOT_AUTOCONF, 1551 .fifosize = 64, 1552 .line = 2, 1553 }, 1554 }, 1555 }; 1556 1557 #define UART_NR ARRAY_SIZE(msm_uart_ports) 1558 1559 static inline struct uart_port *msm_get_port_from_line(unsigned int line) 1560 { 1561 return &msm_uart_ports[line].uart; 1562 } 1563 1564 #ifdef CONFIG_SERIAL_MSM_CONSOLE 1565 static void __msm_console_write(struct uart_port *port, const char *s, 1566 unsigned int count, bool is_uartdm) 1567 { 1568 int i; 1569 int num_newlines = 0; 1570 bool replaced = false; 1571 void __iomem *tf; 1572 1573 if (is_uartdm) 1574 tf = port->membase + UARTDM_TF; 1575 else 1576 tf = port->membase + UART_TF; 1577 1578 /* Account for newlines that will get a carriage return added */ 1579 for (i = 0; i < count; i++) 1580 if (s[i] == '\n') 1581 num_newlines++; 1582 count += num_newlines; 1583 1584 spin_lock(&port->lock); 1585 if (is_uartdm) 1586 msm_reset_dm_count(port, count); 1587 1588 i = 0; 1589 while (i < count) { 1590 int j; 1591 unsigned int num_chars; 1592 char buf[4] = { 0 }; 1593 1594 if (is_uartdm) 1595 num_chars = min(count - i, (unsigned int)sizeof(buf)); 1596 else 1597 num_chars = 1; 1598 1599 for (j = 0; j < num_chars; j++) { 1600 char c = *s; 1601 1602 if (c == '\n' && !replaced) { 1603 buf[j] = '\r'; 1604 j++; 1605 replaced = true; 1606 } 1607 if (j < num_chars) { 1608 buf[j] = c; 1609 s++; 1610 replaced = false; 1611 } 1612 } 1613 1614 while (!(msm_read(port, UART_SR) & UART_SR_TX_READY)) 1615 cpu_relax(); 1616 1617 iowrite32_rep(tf, buf, 1); 1618 i += num_chars; 1619 } 1620 spin_unlock(&port->lock); 1621 } 1622 1623 static void msm_console_write(struct console *co, const char *s, 1624 unsigned int count) 1625 { 1626 struct uart_port *port; 1627 struct msm_port *msm_port; 1628 1629 BUG_ON(co->index < 0 || co->index >= UART_NR); 1630 1631 port = msm_get_port_from_line(co->index); 1632 msm_port = UART_TO_MSM(port); 1633 1634 __msm_console_write(port, s, count, msm_port->is_uartdm); 1635 } 1636 1637 static int __init msm_console_setup(struct console *co, char *options) 1638 { 1639 struct uart_port *port; 1640 int baud = 115200; 1641 int bits = 8; 1642 int parity = 'n'; 1643 int flow = 'n'; 1644 1645 if (unlikely(co->index >= UART_NR || co->index < 0)) 1646 return -ENXIO; 1647 1648 port = msm_get_port_from_line(co->index); 1649 1650 if (unlikely(!port->membase)) 1651 return -ENXIO; 1652 1653 msm_init_clock(port); 1654 1655 if (options) 1656 uart_parse_options(options, &baud, &parity, &bits, &flow); 1657 1658 pr_info("msm_serial: console setup on port #%d\n", port->line); 1659 1660 return uart_set_options(port, co, baud, parity, bits, flow); 1661 } 1662 1663 static void 1664 msm_serial_early_write(struct console *con, const char *s, unsigned n) 1665 { 1666 struct earlycon_device *dev = con->data; 1667 1668 __msm_console_write(&dev->port, s, n, false); 1669 } 1670 1671 static int __init 1672 msm_serial_early_console_setup(struct earlycon_device *device, const char *opt) 1673 { 1674 if (!device->port.membase) 1675 return -ENODEV; 1676 1677 device->con->write = msm_serial_early_write; 1678 return 0; 1679 } 1680 OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart", 1681 msm_serial_early_console_setup); 1682 1683 static void 1684 msm_serial_early_write_dm(struct console *con, const char *s, unsigned n) 1685 { 1686 struct earlycon_device *dev = con->data; 1687 1688 __msm_console_write(&dev->port, s, n, true); 1689 } 1690 1691 static int __init 1692 msm_serial_early_console_setup_dm(struct earlycon_device *device, 1693 const char *opt) 1694 { 1695 if (!device->port.membase) 1696 return -ENODEV; 1697 1698 device->con->write = msm_serial_early_write_dm; 1699 return 0; 1700 } 1701 OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm", 1702 msm_serial_early_console_setup_dm); 1703 1704 static struct uart_driver msm_uart_driver; 1705 1706 static struct console msm_console = { 1707 .name = "ttyMSM", 1708 .write = msm_console_write, 1709 .device = uart_console_device, 1710 .setup = msm_console_setup, 1711 .flags = CON_PRINTBUFFER, 1712 .index = -1, 1713 .data = &msm_uart_driver, 1714 }; 1715 1716 #define MSM_CONSOLE (&msm_console) 1717 1718 #else 1719 #define MSM_CONSOLE NULL 1720 #endif 1721 1722 static struct uart_driver msm_uart_driver = { 1723 .owner = THIS_MODULE, 1724 .driver_name = "msm_serial", 1725 .dev_name = "ttyMSM", 1726 .nr = UART_NR, 1727 .cons = MSM_CONSOLE, 1728 }; 1729 1730 static atomic_t msm_uart_next_id = ATOMIC_INIT(0); 1731 1732 static const struct of_device_id msm_uartdm_table[] = { 1733 { .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 }, 1734 { .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 }, 1735 { .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 }, 1736 { .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 }, 1737 { } 1738 }; 1739 1740 static int msm_serial_probe(struct platform_device *pdev) 1741 { 1742 struct msm_port *msm_port; 1743 struct resource *resource; 1744 struct uart_port *port; 1745 const struct of_device_id *id; 1746 int irq, line; 1747 1748 if (pdev->dev.of_node) 1749 line = of_alias_get_id(pdev->dev.of_node, "serial"); 1750 else 1751 line = pdev->id; 1752 1753 if (line < 0) 1754 line = atomic_inc_return(&msm_uart_next_id) - 1; 1755 1756 if (unlikely(line < 0 || line >= UART_NR)) 1757 return -ENXIO; 1758 1759 dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line); 1760 1761 port = msm_get_port_from_line(line); 1762 port->dev = &pdev->dev; 1763 msm_port = UART_TO_MSM(port); 1764 1765 id = of_match_device(msm_uartdm_table, &pdev->dev); 1766 if (id) 1767 msm_port->is_uartdm = (unsigned long)id->data; 1768 else 1769 msm_port->is_uartdm = 0; 1770 1771 msm_port->clk = devm_clk_get(&pdev->dev, "core"); 1772 if (IS_ERR(msm_port->clk)) 1773 return PTR_ERR(msm_port->clk); 1774 1775 if (msm_port->is_uartdm) { 1776 msm_port->pclk = devm_clk_get(&pdev->dev, "iface"); 1777 if (IS_ERR(msm_port->pclk)) 1778 return PTR_ERR(msm_port->pclk); 1779 } 1780 1781 port->uartclk = clk_get_rate(msm_port->clk); 1782 dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk); 1783 1784 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1785 if (unlikely(!resource)) 1786 return -ENXIO; 1787 port->mapbase = resource->start; 1788 1789 irq = platform_get_irq(pdev, 0); 1790 if (unlikely(irq < 0)) 1791 return -ENXIO; 1792 port->irq = irq; 1793 1794 platform_set_drvdata(pdev, port); 1795 1796 return uart_add_one_port(&msm_uart_driver, port); 1797 } 1798 1799 static int msm_serial_remove(struct platform_device *pdev) 1800 { 1801 struct uart_port *port = platform_get_drvdata(pdev); 1802 1803 uart_remove_one_port(&msm_uart_driver, port); 1804 1805 return 0; 1806 } 1807 1808 static const struct of_device_id msm_match_table[] = { 1809 { .compatible = "qcom,msm-uart" }, 1810 { .compatible = "qcom,msm-uartdm" }, 1811 {} 1812 }; 1813 MODULE_DEVICE_TABLE(of, msm_match_table); 1814 1815 static int __maybe_unused msm_serial_suspend(struct device *dev) 1816 { 1817 struct msm_port *port = dev_get_drvdata(dev); 1818 1819 uart_suspend_port(&msm_uart_driver, &port->uart); 1820 1821 return 0; 1822 } 1823 1824 static int __maybe_unused msm_serial_resume(struct device *dev) 1825 { 1826 struct msm_port *port = dev_get_drvdata(dev); 1827 1828 uart_resume_port(&msm_uart_driver, &port->uart); 1829 1830 return 0; 1831 } 1832 1833 static const struct dev_pm_ops msm_serial_dev_pm_ops = { 1834 SET_SYSTEM_SLEEP_PM_OPS(msm_serial_suspend, msm_serial_resume) 1835 }; 1836 1837 static struct platform_driver msm_platform_driver = { 1838 .remove = msm_serial_remove, 1839 .probe = msm_serial_probe, 1840 .driver = { 1841 .name = "msm_serial", 1842 .pm = &msm_serial_dev_pm_ops, 1843 .of_match_table = msm_match_table, 1844 }, 1845 }; 1846 1847 static int __init msm_serial_init(void) 1848 { 1849 int ret; 1850 1851 ret = uart_register_driver(&msm_uart_driver); 1852 if (unlikely(ret)) 1853 return ret; 1854 1855 ret = platform_driver_register(&msm_platform_driver); 1856 if (unlikely(ret)) 1857 uart_unregister_driver(&msm_uart_driver); 1858 1859 pr_info("msm_serial: driver initialized\n"); 1860 1861 return ret; 1862 } 1863 1864 static void __exit msm_serial_exit(void) 1865 { 1866 platform_driver_unregister(&msm_platform_driver); 1867 uart_unregister_driver(&msm_uart_driver); 1868 } 1869 1870 module_init(msm_serial_init); 1871 module_exit(msm_serial_exit); 1872 1873 MODULE_AUTHOR("Robert Love <rlove@google.com>"); 1874 MODULE_DESCRIPTION("Driver for msm7x serial device"); 1875 MODULE_LICENSE("GPL"); 1876