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