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 #include <linux/kernel.h> 11 #include <linux/atomic.h> 12 #include <linux/dma/qcom_adm.h> 13 #include <linux/dma-mapping.h> 14 #include <linux/dmaengine.h> 15 #include <linux/module.h> 16 #include <linux/io.h> 17 #include <linux/ioport.h> 18 #include <linux/interrupt.h> 19 #include <linux/init.h> 20 #include <linux/console.h> 21 #include <linux/tty.h> 22 #include <linux/tty_flip.h> 23 #include <linux/serial_core.h> 24 #include <linux/slab.h> 25 #include <linux/clk.h> 26 #include <linux/platform_device.h> 27 #include <linux/delay.h> 28 #include <linux/of.h> 29 #include <linux/of_device.h> 30 #include <linux/wait.h> 31 32 #define MSM_UART_MR1 0x0000 33 34 #define MSM_UART_MR1_AUTO_RFR_LEVEL0 0x3F 35 #define MSM_UART_MR1_AUTO_RFR_LEVEL1 0x3FF00 36 #define MSM_UART_DM_MR1_AUTO_RFR_LEVEL1 0xFFFFFF00 37 #define MSM_UART_MR1_RX_RDY_CTL BIT(7) 38 #define MSM_UART_MR1_CTS_CTL BIT(6) 39 40 #define MSM_UART_MR2 0x0004 41 #define MSM_UART_MR2_ERROR_MODE BIT(6) 42 #define MSM_UART_MR2_BITS_PER_CHAR 0x30 43 #define MSM_UART_MR2_BITS_PER_CHAR_5 (0x0 << 4) 44 #define MSM_UART_MR2_BITS_PER_CHAR_6 (0x1 << 4) 45 #define MSM_UART_MR2_BITS_PER_CHAR_7 (0x2 << 4) 46 #define MSM_UART_MR2_BITS_PER_CHAR_8 (0x3 << 4) 47 #define MSM_UART_MR2_STOP_BIT_LEN_ONE (0x1 << 2) 48 #define MSM_UART_MR2_STOP_BIT_LEN_TWO (0x3 << 2) 49 #define MSM_UART_MR2_PARITY_MODE_NONE 0x0 50 #define MSM_UART_MR2_PARITY_MODE_ODD 0x1 51 #define MSM_UART_MR2_PARITY_MODE_EVEN 0x2 52 #define MSM_UART_MR2_PARITY_MODE_SPACE 0x3 53 #define MSM_UART_MR2_PARITY_MODE 0x3 54 55 #define MSM_UART_CSR 0x0008 56 57 #define MSM_UART_TF 0x000C 58 #define UARTDM_TF 0x0070 59 60 #define MSM_UART_CR 0x0010 61 #define MSM_UART_CR_CMD_NULL (0 << 4) 62 #define MSM_UART_CR_CMD_RESET_RX (1 << 4) 63 #define MSM_UART_CR_CMD_RESET_TX (2 << 4) 64 #define MSM_UART_CR_CMD_RESET_ERR (3 << 4) 65 #define MSM_UART_CR_CMD_RESET_BREAK_INT (4 << 4) 66 #define MSM_UART_CR_CMD_START_BREAK (5 << 4) 67 #define MSM_UART_CR_CMD_STOP_BREAK (6 << 4) 68 #define MSM_UART_CR_CMD_RESET_CTS (7 << 4) 69 #define MSM_UART_CR_CMD_RESET_STALE_INT (8 << 4) 70 #define MSM_UART_CR_CMD_PACKET_MODE (9 << 4) 71 #define MSM_UART_CR_CMD_MODE_RESET (12 << 4) 72 #define MSM_UART_CR_CMD_SET_RFR (13 << 4) 73 #define MSM_UART_CR_CMD_RESET_RFR (14 << 4) 74 #define MSM_UART_CR_CMD_PROTECTION_EN (16 << 4) 75 #define MSM_UART_CR_CMD_STALE_EVENT_DISABLE (6 << 8) 76 #define MSM_UART_CR_CMD_STALE_EVENT_ENABLE (80 << 4) 77 #define MSM_UART_CR_CMD_FORCE_STALE (4 << 8) 78 #define MSM_UART_CR_CMD_RESET_TX_READY (3 << 8) 79 #define MSM_UART_CR_TX_DISABLE BIT(3) 80 #define MSM_UART_CR_TX_ENABLE BIT(2) 81 #define MSM_UART_CR_RX_DISABLE BIT(1) 82 #define MSM_UART_CR_RX_ENABLE BIT(0) 83 #define MSM_UART_CR_CMD_RESET_RXBREAK_START ((1 << 11) | (2 << 4)) 84 85 #define MSM_UART_IMR 0x0014 86 #define MSM_UART_IMR_TXLEV BIT(0) 87 #define MSM_UART_IMR_RXSTALE BIT(3) 88 #define MSM_UART_IMR_RXLEV BIT(4) 89 #define MSM_UART_IMR_DELTA_CTS BIT(5) 90 #define MSM_UART_IMR_CURRENT_CTS BIT(6) 91 #define MSM_UART_IMR_RXBREAK_START BIT(10) 92 93 #define MSM_UART_IPR_RXSTALE_LAST 0x20 94 #define MSM_UART_IPR_STALE_LSB 0x1F 95 #define MSM_UART_IPR_STALE_TIMEOUT_MSB 0x3FF80 96 #define MSM_UART_DM_IPR_STALE_TIMEOUT_MSB 0xFFFFFF80 97 98 #define MSM_UART_IPR 0x0018 99 #define MSM_UART_TFWR 0x001C 100 #define MSM_UART_RFWR 0x0020 101 #define MSM_UART_HCR 0x0024 102 103 #define MSM_UART_MREG 0x0028 104 #define MSM_UART_NREG 0x002C 105 #define MSM_UART_DREG 0x0030 106 #define MSM_UART_MNDREG 0x0034 107 #define MSM_UART_IRDA 0x0038 108 #define MSM_UART_MISR_MODE 0x0040 109 #define MSM_UART_MISR_RESET 0x0044 110 #define MSM_UART_MISR_EXPORT 0x0048 111 #define MSM_UART_MISR_VAL 0x004C 112 #define MSM_UART_TEST_CTRL 0x0050 113 114 #define MSM_UART_SR 0x0008 115 #define MSM_UART_SR_HUNT_CHAR BIT(7) 116 #define MSM_UART_SR_RX_BREAK BIT(6) 117 #define MSM_UART_SR_PAR_FRAME_ERR BIT(5) 118 #define MSM_UART_SR_OVERRUN BIT(4) 119 #define MSM_UART_SR_TX_EMPTY BIT(3) 120 #define MSM_UART_SR_TX_READY BIT(2) 121 #define MSM_UART_SR_RX_FULL BIT(1) 122 #define MSM_UART_SR_RX_READY BIT(0) 123 124 #define MSM_UART_RF 0x000C 125 #define UARTDM_RF 0x0070 126 #define MSM_UART_MISR 0x0010 127 #define MSM_UART_ISR 0x0014 128 #define MSM_UART_ISR_TX_READY BIT(7) 129 130 #define UARTDM_RXFS 0x50 131 #define UARTDM_RXFS_BUF_SHIFT 0x7 132 #define UARTDM_RXFS_BUF_MASK 0x7 133 134 #define UARTDM_DMEN 0x3C 135 #define UARTDM_DMEN_RX_SC_ENABLE BIT(5) 136 #define UARTDM_DMEN_TX_SC_ENABLE BIT(4) 137 138 #define UARTDM_DMEN_TX_BAM_ENABLE BIT(2) /* UARTDM_1P4 */ 139 #define UARTDM_DMEN_TX_DM_ENABLE BIT(0) /* < UARTDM_1P4 */ 140 141 #define UARTDM_DMEN_RX_BAM_ENABLE BIT(3) /* UARTDM_1P4 */ 142 #define UARTDM_DMEN_RX_DM_ENABLE BIT(1) /* < UARTDM_1P4 */ 143 144 #define UARTDM_DMRX 0x34 145 #define UARTDM_NCF_TX 0x40 146 #define UARTDM_RX_TOTAL_SNAP 0x38 147 148 #define UARTDM_BURST_SIZE 16 /* in bytes */ 149 #define UARTDM_TX_AIGN(x) ((x) & ~0x3) /* valid for > 1p3 */ 150 #define UARTDM_TX_MAX 256 /* in bytes, valid for <= 1p3 */ 151 #define UARTDM_RX_SIZE (UART_XMIT_SIZE / 4) 152 153 enum { 154 UARTDM_1P1 = 1, 155 UARTDM_1P2, 156 UARTDM_1P3, 157 UARTDM_1P4, 158 }; 159 160 struct msm_dma { 161 struct dma_chan *chan; 162 enum dma_data_direction dir; 163 dma_addr_t phys; 164 unsigned char *virt; 165 dma_cookie_t cookie; 166 u32 enable_bit; 167 unsigned int count; 168 struct dma_async_tx_descriptor *desc; 169 }; 170 171 struct msm_port { 172 struct uart_port uart; 173 char name[16]; 174 struct clk *clk; 175 struct clk *pclk; 176 unsigned int imr; 177 int is_uartdm; 178 unsigned int old_snap_state; 179 bool break_detected; 180 struct msm_dma tx_dma; 181 struct msm_dma rx_dma; 182 }; 183 184 static inline struct msm_port *to_msm_port(struct uart_port *up) 185 { 186 return container_of(up, struct msm_port, uart); 187 } 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, MSM_UART_MREG); 207 msm_write(port, 0xF1, MSM_UART_NREG); 208 msm_write(port, 0x0F, MSM_UART_DREG); 209 msm_write(port, 0x1A, MSM_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, MSM_UART_MREG); 219 msm_write(port, 0xF6, MSM_UART_NREG); 220 msm_write(port, 0x0F, MSM_UART_DREG); 221 msm_write(port, 0x0A, MSM_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 = to_msm_port(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 qcom_adm_peripheral_config periph_conf = {}; 298 struct msm_dma *dma; 299 u32 crci = 0; 300 int ret; 301 302 dma = &msm_port->tx_dma; 303 304 /* allocate DMA resources, if available */ 305 dma->chan = dma_request_chan(dev, "tx"); 306 if (IS_ERR(dma->chan)) 307 goto no_tx; 308 309 of_property_read_u32(dev->of_node, "qcom,tx-crci", &crci); 310 311 memset(&conf, 0, sizeof(conf)); 312 conf.direction = DMA_MEM_TO_DEV; 313 conf.device_fc = true; 314 conf.dst_addr = base + UARTDM_TF; 315 conf.dst_maxburst = UARTDM_BURST_SIZE; 316 if (crci) { 317 conf.peripheral_config = &periph_conf; 318 conf.peripheral_size = sizeof(periph_conf); 319 periph_conf.crci = crci; 320 } 321 322 ret = dmaengine_slave_config(dma->chan, &conf); 323 if (ret) 324 goto rel_tx; 325 326 dma->dir = DMA_TO_DEVICE; 327 328 if (msm_port->is_uartdm < UARTDM_1P4) 329 dma->enable_bit = UARTDM_DMEN_TX_DM_ENABLE; 330 else 331 dma->enable_bit = UARTDM_DMEN_TX_BAM_ENABLE; 332 333 return; 334 335 rel_tx: 336 dma_release_channel(dma->chan); 337 no_tx: 338 memset(dma, 0, sizeof(*dma)); 339 } 340 341 static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base) 342 { 343 struct device *dev = msm_port->uart.dev; 344 struct dma_slave_config conf; 345 struct qcom_adm_peripheral_config periph_conf = {}; 346 struct msm_dma *dma; 347 u32 crci = 0; 348 int ret; 349 350 dma = &msm_port->rx_dma; 351 352 /* allocate DMA resources, if available */ 353 dma->chan = dma_request_chan(dev, "rx"); 354 if (IS_ERR(dma->chan)) 355 goto no_rx; 356 357 of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci); 358 359 dma->virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL); 360 if (!dma->virt) 361 goto rel_rx; 362 363 memset(&conf, 0, sizeof(conf)); 364 conf.direction = DMA_DEV_TO_MEM; 365 conf.device_fc = true; 366 conf.src_addr = base + UARTDM_RF; 367 conf.src_maxburst = UARTDM_BURST_SIZE; 368 if (crci) { 369 conf.peripheral_config = &periph_conf; 370 conf.peripheral_size = sizeof(periph_conf); 371 periph_conf.crci = crci; 372 } 373 374 ret = dmaengine_slave_config(dma->chan, &conf); 375 if (ret) 376 goto err; 377 378 dma->dir = DMA_FROM_DEVICE; 379 380 if (msm_port->is_uartdm < UARTDM_1P4) 381 dma->enable_bit = UARTDM_DMEN_RX_DM_ENABLE; 382 else 383 dma->enable_bit = UARTDM_DMEN_RX_BAM_ENABLE; 384 385 return; 386 err: 387 kfree(dma->virt); 388 rel_rx: 389 dma_release_channel(dma->chan); 390 no_rx: 391 memset(dma, 0, sizeof(*dma)); 392 } 393 394 static inline void msm_wait_for_xmitr(struct uart_port *port) 395 { 396 unsigned int timeout = 500000; 397 398 while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_EMPTY)) { 399 if (msm_read(port, MSM_UART_ISR) & MSM_UART_ISR_TX_READY) 400 break; 401 udelay(1); 402 if (!timeout--) 403 break; 404 } 405 msm_write(port, MSM_UART_CR_CMD_RESET_TX_READY, MSM_UART_CR); 406 } 407 408 static void msm_stop_tx(struct uart_port *port) 409 { 410 struct msm_port *msm_port = to_msm_port(port); 411 412 msm_port->imr &= ~MSM_UART_IMR_TXLEV; 413 msm_write(port, msm_port->imr, MSM_UART_IMR); 414 } 415 416 static void msm_start_tx(struct uart_port *port) 417 { 418 struct msm_port *msm_port = to_msm_port(port); 419 struct msm_dma *dma = &msm_port->tx_dma; 420 421 /* Already started in DMA mode */ 422 if (dma->count) 423 return; 424 425 msm_port->imr |= MSM_UART_IMR_TXLEV; 426 msm_write(port, msm_port->imr, MSM_UART_IMR); 427 } 428 429 static void msm_reset_dm_count(struct uart_port *port, int count) 430 { 431 msm_wait_for_xmitr(port); 432 msm_write(port, count, UARTDM_NCF_TX); 433 msm_read(port, UARTDM_NCF_TX); 434 } 435 436 static void msm_complete_tx_dma(void *args) 437 { 438 struct msm_port *msm_port = args; 439 struct uart_port *port = &msm_port->uart; 440 struct circ_buf *xmit = &port->state->xmit; 441 struct msm_dma *dma = &msm_port->tx_dma; 442 struct dma_tx_state state; 443 unsigned long flags; 444 unsigned int count; 445 u32 val; 446 447 spin_lock_irqsave(&port->lock, flags); 448 449 /* Already stopped */ 450 if (!dma->count) 451 goto done; 452 453 dmaengine_tx_status(dma->chan, dma->cookie, &state); 454 455 dma_unmap_single(port->dev, dma->phys, dma->count, dma->dir); 456 457 val = msm_read(port, UARTDM_DMEN); 458 val &= ~dma->enable_bit; 459 msm_write(port, val, UARTDM_DMEN); 460 461 if (msm_port->is_uartdm > UARTDM_1P3) { 462 msm_write(port, MSM_UART_CR_CMD_RESET_TX, MSM_UART_CR); 463 msm_write(port, MSM_UART_CR_TX_ENABLE, MSM_UART_CR); 464 } 465 466 count = dma->count - state.residue; 467 uart_xmit_advance(port, count); 468 dma->count = 0; 469 470 /* Restore "Tx FIFO below watermark" interrupt */ 471 msm_port->imr |= MSM_UART_IMR_TXLEV; 472 msm_write(port, msm_port->imr, MSM_UART_IMR); 473 474 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 475 uart_write_wakeup(port); 476 477 msm_handle_tx(port); 478 done: 479 spin_unlock_irqrestore(&port->lock, flags); 480 } 481 482 static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count) 483 { 484 struct circ_buf *xmit = &msm_port->uart.state->xmit; 485 struct uart_port *port = &msm_port->uart; 486 struct msm_dma *dma = &msm_port->tx_dma; 487 void *cpu_addr; 488 int ret; 489 u32 val; 490 491 cpu_addr = &xmit->buf[xmit->tail]; 492 493 dma->phys = dma_map_single(port->dev, cpu_addr, count, dma->dir); 494 ret = dma_mapping_error(port->dev, dma->phys); 495 if (ret) 496 return ret; 497 498 dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, 499 count, DMA_MEM_TO_DEV, 500 DMA_PREP_INTERRUPT | 501 DMA_PREP_FENCE); 502 if (!dma->desc) { 503 ret = -EIO; 504 goto unmap; 505 } 506 507 dma->desc->callback = msm_complete_tx_dma; 508 dma->desc->callback_param = msm_port; 509 510 dma->cookie = dmaengine_submit(dma->desc); 511 ret = dma_submit_error(dma->cookie); 512 if (ret) 513 goto unmap; 514 515 /* 516 * Using DMA complete for Tx FIFO reload, no need for 517 * "Tx FIFO below watermark" one, disable it 518 */ 519 msm_port->imr &= ~MSM_UART_IMR_TXLEV; 520 msm_write(port, msm_port->imr, MSM_UART_IMR); 521 522 dma->count = count; 523 524 val = msm_read(port, UARTDM_DMEN); 525 val |= dma->enable_bit; 526 527 if (msm_port->is_uartdm < UARTDM_1P4) 528 msm_write(port, val, UARTDM_DMEN); 529 530 msm_reset_dm_count(port, count); 531 532 if (msm_port->is_uartdm > UARTDM_1P3) 533 msm_write(port, val, UARTDM_DMEN); 534 535 dma_async_issue_pending(dma->chan); 536 return 0; 537 unmap: 538 dma_unmap_single(port->dev, dma->phys, count, dma->dir); 539 return ret; 540 } 541 542 static void msm_complete_rx_dma(void *args) 543 { 544 struct msm_port *msm_port = args; 545 struct uart_port *port = &msm_port->uart; 546 struct tty_port *tport = &port->state->port; 547 struct msm_dma *dma = &msm_port->rx_dma; 548 int count = 0, i, sysrq; 549 unsigned long flags; 550 u32 val; 551 552 spin_lock_irqsave(&port->lock, flags); 553 554 /* Already stopped */ 555 if (!dma->count) 556 goto done; 557 558 val = msm_read(port, UARTDM_DMEN); 559 val &= ~dma->enable_bit; 560 msm_write(port, val, UARTDM_DMEN); 561 562 if (msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN) { 563 port->icount.overrun++; 564 tty_insert_flip_char(tport, 0, TTY_OVERRUN); 565 msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR); 566 } 567 568 count = msm_read(port, UARTDM_RX_TOTAL_SNAP); 569 570 port->icount.rx += count; 571 572 dma->count = 0; 573 574 dma_unmap_single(port->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); 575 576 for (i = 0; i < count; i++) { 577 char flag = TTY_NORMAL; 578 579 if (msm_port->break_detected && dma->virt[i] == 0) { 580 port->icount.brk++; 581 flag = TTY_BREAK; 582 msm_port->break_detected = false; 583 if (uart_handle_break(port)) 584 continue; 585 } 586 587 if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK)) 588 flag = TTY_NORMAL; 589 590 spin_unlock_irqrestore(&port->lock, flags); 591 sysrq = uart_handle_sysrq_char(port, dma->virt[i]); 592 spin_lock_irqsave(&port->lock, flags); 593 if (!sysrq) 594 tty_insert_flip_char(tport, dma->virt[i], flag); 595 } 596 597 msm_start_rx_dma(msm_port); 598 done: 599 spin_unlock_irqrestore(&port->lock, flags); 600 601 if (count) 602 tty_flip_buffer_push(tport); 603 } 604 605 static void msm_start_rx_dma(struct msm_port *msm_port) 606 { 607 struct msm_dma *dma = &msm_port->rx_dma; 608 struct uart_port *uart = &msm_port->uart; 609 u32 val; 610 int ret; 611 612 if (IS_ENABLED(CONFIG_CONSOLE_POLL)) 613 return; 614 615 if (!dma->chan) 616 return; 617 618 dma->phys = dma_map_single(uart->dev, dma->virt, 619 UARTDM_RX_SIZE, dma->dir); 620 ret = dma_mapping_error(uart->dev, dma->phys); 621 if (ret) 622 goto sw_mode; 623 624 dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, 625 UARTDM_RX_SIZE, DMA_DEV_TO_MEM, 626 DMA_PREP_INTERRUPT); 627 if (!dma->desc) 628 goto unmap; 629 630 dma->desc->callback = msm_complete_rx_dma; 631 dma->desc->callback_param = msm_port; 632 633 dma->cookie = dmaengine_submit(dma->desc); 634 ret = dma_submit_error(dma->cookie); 635 if (ret) 636 goto unmap; 637 /* 638 * Using DMA for FIFO off-load, no need for "Rx FIFO over 639 * watermark" or "stale" interrupts, disable them 640 */ 641 msm_port->imr &= ~(MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE); 642 643 /* 644 * Well, when DMA is ADM3 engine(implied by <= UARTDM v1.3), 645 * we need RXSTALE to flush input DMA fifo to memory 646 */ 647 if (msm_port->is_uartdm < UARTDM_1P4) 648 msm_port->imr |= MSM_UART_IMR_RXSTALE; 649 650 msm_write(uart, msm_port->imr, MSM_UART_IMR); 651 652 dma->count = UARTDM_RX_SIZE; 653 654 dma_async_issue_pending(dma->chan); 655 656 msm_write(uart, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR); 657 msm_write(uart, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR); 658 659 val = msm_read(uart, UARTDM_DMEN); 660 val |= dma->enable_bit; 661 662 if (msm_port->is_uartdm < UARTDM_1P4) 663 msm_write(uart, val, UARTDM_DMEN); 664 665 msm_write(uart, UARTDM_RX_SIZE, UARTDM_DMRX); 666 667 if (msm_port->is_uartdm > UARTDM_1P3) 668 msm_write(uart, val, UARTDM_DMEN); 669 670 return; 671 unmap: 672 dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); 673 674 sw_mode: 675 /* 676 * Switch from DMA to SW/FIFO mode. After clearing Rx BAM (UARTDM_DMEN), 677 * receiver must be reset. 678 */ 679 msm_write(uart, MSM_UART_CR_CMD_RESET_RX, MSM_UART_CR); 680 msm_write(uart, MSM_UART_CR_RX_ENABLE, MSM_UART_CR); 681 682 msm_write(uart, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR); 683 msm_write(uart, 0xFFFFFF, UARTDM_DMRX); 684 msm_write(uart, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR); 685 686 /* Re-enable RX interrupts */ 687 msm_port->imr |= MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE; 688 msm_write(uart, msm_port->imr, MSM_UART_IMR); 689 } 690 691 static void msm_stop_rx(struct uart_port *port) 692 { 693 struct msm_port *msm_port = to_msm_port(port); 694 struct msm_dma *dma = &msm_port->rx_dma; 695 696 msm_port->imr &= ~(MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE); 697 msm_write(port, msm_port->imr, MSM_UART_IMR); 698 699 if (dma->chan) 700 msm_stop_dma(port, dma); 701 } 702 703 static void msm_enable_ms(struct uart_port *port) 704 { 705 struct msm_port *msm_port = to_msm_port(port); 706 707 msm_port->imr |= MSM_UART_IMR_DELTA_CTS; 708 msm_write(port, msm_port->imr, MSM_UART_IMR); 709 } 710 711 static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr) 712 __must_hold(&port->lock) 713 { 714 struct tty_port *tport = &port->state->port; 715 unsigned int sr; 716 int count = 0; 717 struct msm_port *msm_port = to_msm_port(port); 718 719 if ((msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN)) { 720 port->icount.overrun++; 721 tty_insert_flip_char(tport, 0, TTY_OVERRUN); 722 msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR); 723 } 724 725 if (misr & MSM_UART_IMR_RXSTALE) { 726 count = msm_read(port, UARTDM_RX_TOTAL_SNAP) - 727 msm_port->old_snap_state; 728 msm_port->old_snap_state = 0; 729 } else { 730 count = 4 * (msm_read(port, MSM_UART_RFWR)); 731 msm_port->old_snap_state += count; 732 } 733 734 /* TODO: Precise error reporting */ 735 736 port->icount.rx += count; 737 738 while (count > 0) { 739 unsigned char buf[4]; 740 int sysrq, r_count, i; 741 742 sr = msm_read(port, MSM_UART_SR); 743 if ((sr & MSM_UART_SR_RX_READY) == 0) { 744 msm_port->old_snap_state -= count; 745 break; 746 } 747 748 ioread32_rep(port->membase + UARTDM_RF, buf, 1); 749 r_count = min_t(int, count, sizeof(buf)); 750 751 for (i = 0; i < r_count; i++) { 752 char flag = TTY_NORMAL; 753 754 if (msm_port->break_detected && buf[i] == 0) { 755 port->icount.brk++; 756 flag = TTY_BREAK; 757 msm_port->break_detected = false; 758 if (uart_handle_break(port)) 759 continue; 760 } 761 762 if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK)) 763 flag = TTY_NORMAL; 764 765 spin_unlock(&port->lock); 766 sysrq = uart_handle_sysrq_char(port, buf[i]); 767 spin_lock(&port->lock); 768 if (!sysrq) 769 tty_insert_flip_char(tport, buf[i], flag); 770 } 771 count -= r_count; 772 } 773 774 tty_flip_buffer_push(tport); 775 776 if (misr & (MSM_UART_IMR_RXSTALE)) 777 msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR); 778 msm_write(port, 0xFFFFFF, UARTDM_DMRX); 779 msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR); 780 781 /* Try to use DMA */ 782 msm_start_rx_dma(msm_port); 783 } 784 785 static void msm_handle_rx(struct uart_port *port) 786 __must_hold(&port->lock) 787 { 788 struct tty_port *tport = &port->state->port; 789 unsigned int sr; 790 791 /* 792 * Handle overrun. My understanding of the hardware is that overrun 793 * is not tied to the RX buffer, so we handle the case out of band. 794 */ 795 if ((msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN)) { 796 port->icount.overrun++; 797 tty_insert_flip_char(tport, 0, TTY_OVERRUN); 798 msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR); 799 } 800 801 /* and now the main RX loop */ 802 while ((sr = msm_read(port, MSM_UART_SR)) & MSM_UART_SR_RX_READY) { 803 unsigned int c; 804 char flag = TTY_NORMAL; 805 int sysrq; 806 807 c = msm_read(port, MSM_UART_RF); 808 809 if (sr & MSM_UART_SR_RX_BREAK) { 810 port->icount.brk++; 811 if (uart_handle_break(port)) 812 continue; 813 } else if (sr & MSM_UART_SR_PAR_FRAME_ERR) { 814 port->icount.frame++; 815 } else { 816 port->icount.rx++; 817 } 818 819 /* Mask conditions we're ignoring. */ 820 sr &= port->read_status_mask; 821 822 if (sr & MSM_UART_SR_RX_BREAK) 823 flag = TTY_BREAK; 824 else if (sr & MSM_UART_SR_PAR_FRAME_ERR) 825 flag = TTY_FRAME; 826 827 spin_unlock(&port->lock); 828 sysrq = uart_handle_sysrq_char(port, c); 829 spin_lock(&port->lock); 830 if (!sysrq) 831 tty_insert_flip_char(tport, c, flag); 832 } 833 834 tty_flip_buffer_push(tport); 835 } 836 837 static void msm_handle_tx_pio(struct uart_port *port, unsigned int tx_count) 838 { 839 struct circ_buf *xmit = &port->state->xmit; 840 struct msm_port *msm_port = to_msm_port(port); 841 unsigned int num_chars; 842 unsigned int tf_pointer = 0; 843 void __iomem *tf; 844 845 if (msm_port->is_uartdm) 846 tf = port->membase + UARTDM_TF; 847 else 848 tf = port->membase + MSM_UART_TF; 849 850 if (tx_count && msm_port->is_uartdm) 851 msm_reset_dm_count(port, tx_count); 852 853 while (tf_pointer < tx_count) { 854 int i; 855 char buf[4] = { 0 }; 856 857 if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY)) 858 break; 859 860 if (msm_port->is_uartdm) 861 num_chars = min(tx_count - tf_pointer, 862 (unsigned int)sizeof(buf)); 863 else 864 num_chars = 1; 865 866 for (i = 0; i < num_chars; i++) 867 buf[i] = xmit->buf[xmit->tail + i]; 868 869 iowrite32_rep(tf, buf, 1); 870 uart_xmit_advance(port, num_chars); 871 tf_pointer += num_chars; 872 } 873 874 /* disable tx interrupts if nothing more to send */ 875 if (uart_circ_empty(xmit)) 876 msm_stop_tx(port); 877 878 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) 879 uart_write_wakeup(port); 880 } 881 882 static void msm_handle_tx(struct uart_port *port) 883 { 884 struct msm_port *msm_port = to_msm_port(port); 885 struct circ_buf *xmit = &msm_port->uart.state->xmit; 886 struct msm_dma *dma = &msm_port->tx_dma; 887 unsigned int pio_count, dma_count, dma_min; 888 char buf[4] = { 0 }; 889 void __iomem *tf; 890 int err = 0; 891 892 if (port->x_char) { 893 if (msm_port->is_uartdm) 894 tf = port->membase + UARTDM_TF; 895 else 896 tf = port->membase + MSM_UART_TF; 897 898 buf[0] = port->x_char; 899 900 if (msm_port->is_uartdm) 901 msm_reset_dm_count(port, 1); 902 903 iowrite32_rep(tf, buf, 1); 904 port->icount.tx++; 905 port->x_char = 0; 906 return; 907 } 908 909 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { 910 msm_stop_tx(port); 911 return; 912 } 913 914 pio_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); 915 dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); 916 917 dma_min = 1; /* Always DMA */ 918 if (msm_port->is_uartdm > UARTDM_1P3) { 919 dma_count = UARTDM_TX_AIGN(dma_count); 920 dma_min = UARTDM_BURST_SIZE; 921 } else { 922 if (dma_count > UARTDM_TX_MAX) 923 dma_count = UARTDM_TX_MAX; 924 } 925 926 if (pio_count > port->fifosize) 927 pio_count = port->fifosize; 928 929 if (!dma->chan || dma_count < dma_min) 930 msm_handle_tx_pio(port, pio_count); 931 else 932 err = msm_handle_tx_dma(msm_port, dma_count); 933 934 if (err) /* fall back to PIO mode */ 935 msm_handle_tx_pio(port, pio_count); 936 } 937 938 static void msm_handle_delta_cts(struct uart_port *port) 939 { 940 msm_write(port, MSM_UART_CR_CMD_RESET_CTS, MSM_UART_CR); 941 port->icount.cts++; 942 wake_up_interruptible(&port->state->port.delta_msr_wait); 943 } 944 945 static irqreturn_t msm_uart_irq(int irq, void *dev_id) 946 { 947 struct uart_port *port = dev_id; 948 struct msm_port *msm_port = to_msm_port(port); 949 struct msm_dma *dma = &msm_port->rx_dma; 950 unsigned long flags; 951 unsigned int misr; 952 u32 val; 953 954 spin_lock_irqsave(&port->lock, flags); 955 misr = msm_read(port, MSM_UART_MISR); 956 msm_write(port, 0, MSM_UART_IMR); /* disable interrupt */ 957 958 if (misr & MSM_UART_IMR_RXBREAK_START) { 959 msm_port->break_detected = true; 960 msm_write(port, MSM_UART_CR_CMD_RESET_RXBREAK_START, MSM_UART_CR); 961 } 962 963 if (misr & (MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE)) { 964 if (dma->count) { 965 val = MSM_UART_CR_CMD_STALE_EVENT_DISABLE; 966 msm_write(port, val, MSM_UART_CR); 967 val = MSM_UART_CR_CMD_RESET_STALE_INT; 968 msm_write(port, val, MSM_UART_CR); 969 /* 970 * Flush DMA input fifo to memory, this will also 971 * trigger DMA RX completion 972 */ 973 dmaengine_terminate_all(dma->chan); 974 } else if (msm_port->is_uartdm) { 975 msm_handle_rx_dm(port, misr); 976 } else { 977 msm_handle_rx(port); 978 } 979 } 980 if (misr & MSM_UART_IMR_TXLEV) 981 msm_handle_tx(port); 982 if (misr & MSM_UART_IMR_DELTA_CTS) 983 msm_handle_delta_cts(port); 984 985 msm_write(port, msm_port->imr, MSM_UART_IMR); /* restore interrupt */ 986 spin_unlock_irqrestore(&port->lock, flags); 987 988 return IRQ_HANDLED; 989 } 990 991 static unsigned int msm_tx_empty(struct uart_port *port) 992 { 993 return (msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0; 994 } 995 996 static unsigned int msm_get_mctrl(struct uart_port *port) 997 { 998 return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS; 999 } 1000 1001 static void msm_reset(struct uart_port *port) 1002 { 1003 struct msm_port *msm_port = to_msm_port(port); 1004 unsigned int mr; 1005 1006 /* reset everything */ 1007 msm_write(port, MSM_UART_CR_CMD_RESET_RX, MSM_UART_CR); 1008 msm_write(port, MSM_UART_CR_CMD_RESET_TX, MSM_UART_CR); 1009 msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR); 1010 msm_write(port, MSM_UART_CR_CMD_RESET_BREAK_INT, MSM_UART_CR); 1011 msm_write(port, MSM_UART_CR_CMD_RESET_CTS, MSM_UART_CR); 1012 msm_write(port, MSM_UART_CR_CMD_RESET_RFR, MSM_UART_CR); 1013 mr = msm_read(port, MSM_UART_MR1); 1014 mr &= ~MSM_UART_MR1_RX_RDY_CTL; 1015 msm_write(port, mr, MSM_UART_MR1); 1016 1017 /* Disable DM modes */ 1018 if (msm_port->is_uartdm) 1019 msm_write(port, 0, UARTDM_DMEN); 1020 } 1021 1022 static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl) 1023 { 1024 unsigned int mr; 1025 1026 mr = msm_read(port, MSM_UART_MR1); 1027 1028 if (!(mctrl & TIOCM_RTS)) { 1029 mr &= ~MSM_UART_MR1_RX_RDY_CTL; 1030 msm_write(port, mr, MSM_UART_MR1); 1031 msm_write(port, MSM_UART_CR_CMD_RESET_RFR, MSM_UART_CR); 1032 } else { 1033 mr |= MSM_UART_MR1_RX_RDY_CTL; 1034 msm_write(port, mr, MSM_UART_MR1); 1035 } 1036 } 1037 1038 static void msm_break_ctl(struct uart_port *port, int break_ctl) 1039 { 1040 if (break_ctl) 1041 msm_write(port, MSM_UART_CR_CMD_START_BREAK, MSM_UART_CR); 1042 else 1043 msm_write(port, MSM_UART_CR_CMD_STOP_BREAK, MSM_UART_CR); 1044 } 1045 1046 struct msm_baud_map { 1047 u16 divisor; 1048 u8 code; 1049 u8 rxstale; 1050 }; 1051 1052 static const struct msm_baud_map * 1053 msm_find_best_baud(struct uart_port *port, unsigned int baud, 1054 unsigned long *rate) 1055 { 1056 struct msm_port *msm_port = to_msm_port(port); 1057 unsigned int divisor, result; 1058 unsigned long target, old, best_rate = 0, diff, best_diff = ULONG_MAX; 1059 const struct msm_baud_map *entry, *end, *best; 1060 static const struct msm_baud_map table[] = { 1061 { 1, 0xff, 31 }, 1062 { 2, 0xee, 16 }, 1063 { 3, 0xdd, 8 }, 1064 { 4, 0xcc, 6 }, 1065 { 6, 0xbb, 6 }, 1066 { 8, 0xaa, 6 }, 1067 { 12, 0x99, 6 }, 1068 { 16, 0x88, 1 }, 1069 { 24, 0x77, 1 }, 1070 { 32, 0x66, 1 }, 1071 { 48, 0x55, 1 }, 1072 { 96, 0x44, 1 }, 1073 { 192, 0x33, 1 }, 1074 { 384, 0x22, 1 }, 1075 { 768, 0x11, 1 }, 1076 { 1536, 0x00, 1 }, 1077 }; 1078 1079 best = table; /* Default to smallest divider */ 1080 target = clk_round_rate(msm_port->clk, 16 * baud); 1081 divisor = DIV_ROUND_CLOSEST(target, 16 * baud); 1082 1083 end = table + ARRAY_SIZE(table); 1084 entry = table; 1085 while (entry < end) { 1086 if (entry->divisor <= divisor) { 1087 result = target / entry->divisor / 16; 1088 diff = abs(result - baud); 1089 1090 /* Keep track of best entry */ 1091 if (diff < best_diff) { 1092 best_diff = diff; 1093 best = entry; 1094 best_rate = target; 1095 } 1096 1097 if (result == baud) 1098 break; 1099 } else if (entry->divisor > divisor) { 1100 old = target; 1101 target = clk_round_rate(msm_port->clk, old + 1); 1102 /* 1103 * The rate didn't get any faster so we can't do 1104 * better at dividing it down 1105 */ 1106 if (target == old) 1107 break; 1108 1109 /* Start the divisor search over at this new rate */ 1110 entry = table; 1111 divisor = DIV_ROUND_CLOSEST(target, 16 * baud); 1112 continue; 1113 } 1114 entry++; 1115 } 1116 1117 *rate = best_rate; 1118 return best; 1119 } 1120 1121 static int msm_set_baud_rate(struct uart_port *port, unsigned int baud, 1122 unsigned long *saved_flags) 1123 __must_hold(&port->lock) 1124 { 1125 unsigned int rxstale, watermark, mask; 1126 struct msm_port *msm_port = to_msm_port(port); 1127 const struct msm_baud_map *entry; 1128 unsigned long flags, rate; 1129 1130 flags = *saved_flags; 1131 spin_unlock_irqrestore(&port->lock, flags); 1132 1133 entry = msm_find_best_baud(port, baud, &rate); 1134 clk_set_rate(msm_port->clk, rate); 1135 baud = rate / 16 / entry->divisor; 1136 1137 spin_lock_irqsave(&port->lock, flags); 1138 *saved_flags = flags; 1139 port->uartclk = rate; 1140 1141 msm_write(port, entry->code, MSM_UART_CSR); 1142 1143 /* RX stale watermark */ 1144 rxstale = entry->rxstale; 1145 watermark = MSM_UART_IPR_STALE_LSB & rxstale; 1146 if (msm_port->is_uartdm) { 1147 mask = MSM_UART_DM_IPR_STALE_TIMEOUT_MSB; 1148 } else { 1149 watermark |= MSM_UART_IPR_RXSTALE_LAST; 1150 mask = MSM_UART_IPR_STALE_TIMEOUT_MSB; 1151 } 1152 1153 watermark |= mask & (rxstale << 2); 1154 1155 msm_write(port, watermark, MSM_UART_IPR); 1156 1157 /* set RX watermark */ 1158 watermark = (port->fifosize * 3) / 4; 1159 msm_write(port, watermark, MSM_UART_RFWR); 1160 1161 /* set TX watermark */ 1162 msm_write(port, 10, MSM_UART_TFWR); 1163 1164 msm_write(port, MSM_UART_CR_CMD_PROTECTION_EN, MSM_UART_CR); 1165 msm_reset(port); 1166 1167 /* Enable RX and TX */ 1168 msm_write(port, MSM_UART_CR_TX_ENABLE | MSM_UART_CR_RX_ENABLE, MSM_UART_CR); 1169 1170 /* turn on RX and CTS interrupts */ 1171 msm_port->imr = MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE | 1172 MSM_UART_IMR_CURRENT_CTS | MSM_UART_IMR_RXBREAK_START; 1173 1174 msm_write(port, msm_port->imr, MSM_UART_IMR); 1175 1176 if (msm_port->is_uartdm) { 1177 msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR); 1178 msm_write(port, 0xFFFFFF, UARTDM_DMRX); 1179 msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR); 1180 } 1181 1182 return baud; 1183 } 1184 1185 static void msm_init_clock(struct uart_port *port) 1186 { 1187 struct msm_port *msm_port = to_msm_port(port); 1188 1189 clk_prepare_enable(msm_port->clk); 1190 clk_prepare_enable(msm_port->pclk); 1191 msm_serial_set_mnd_regs(port); 1192 } 1193 1194 static int msm_startup(struct uart_port *port) 1195 { 1196 struct msm_port *msm_port = to_msm_port(port); 1197 unsigned int data, rfr_level, mask; 1198 int ret; 1199 1200 snprintf(msm_port->name, sizeof(msm_port->name), 1201 "msm_serial%d", port->line); 1202 1203 msm_init_clock(port); 1204 1205 if (likely(port->fifosize > 12)) 1206 rfr_level = port->fifosize - 12; 1207 else 1208 rfr_level = port->fifosize; 1209 1210 /* set automatic RFR level */ 1211 data = msm_read(port, MSM_UART_MR1); 1212 1213 if (msm_port->is_uartdm) 1214 mask = MSM_UART_DM_MR1_AUTO_RFR_LEVEL1; 1215 else 1216 mask = MSM_UART_MR1_AUTO_RFR_LEVEL1; 1217 1218 data &= ~mask; 1219 data &= ~MSM_UART_MR1_AUTO_RFR_LEVEL0; 1220 data |= mask & (rfr_level << 2); 1221 data |= MSM_UART_MR1_AUTO_RFR_LEVEL0 & rfr_level; 1222 msm_write(port, data, MSM_UART_MR1); 1223 1224 if (msm_port->is_uartdm) { 1225 msm_request_tx_dma(msm_port, msm_port->uart.mapbase); 1226 msm_request_rx_dma(msm_port, msm_port->uart.mapbase); 1227 } 1228 1229 ret = request_irq(port->irq, msm_uart_irq, IRQF_TRIGGER_HIGH, 1230 msm_port->name, port); 1231 if (unlikely(ret)) 1232 goto err_irq; 1233 1234 return 0; 1235 1236 err_irq: 1237 if (msm_port->is_uartdm) 1238 msm_release_dma(msm_port); 1239 1240 clk_disable_unprepare(msm_port->pclk); 1241 clk_disable_unprepare(msm_port->clk); 1242 1243 return ret; 1244 } 1245 1246 static void msm_shutdown(struct uart_port *port) 1247 { 1248 struct msm_port *msm_port = to_msm_port(port); 1249 1250 msm_port->imr = 0; 1251 msm_write(port, 0, MSM_UART_IMR); /* disable interrupts */ 1252 1253 if (msm_port->is_uartdm) 1254 msm_release_dma(msm_port); 1255 1256 clk_disable_unprepare(msm_port->clk); 1257 1258 free_irq(port->irq, port); 1259 } 1260 1261 static void msm_set_termios(struct uart_port *port, struct ktermios *termios, 1262 const struct ktermios *old) 1263 { 1264 struct msm_port *msm_port = to_msm_port(port); 1265 struct msm_dma *dma = &msm_port->rx_dma; 1266 unsigned long flags; 1267 unsigned int baud, mr; 1268 1269 spin_lock_irqsave(&port->lock, flags); 1270 1271 if (dma->chan) /* Terminate if any */ 1272 msm_stop_dma(port, dma); 1273 1274 /* calculate and set baud rate */ 1275 baud = uart_get_baud_rate(port, termios, old, 300, 4000000); 1276 baud = msm_set_baud_rate(port, baud, &flags); 1277 if (tty_termios_baud_rate(termios)) 1278 tty_termios_encode_baud_rate(termios, baud, baud); 1279 1280 /* calculate parity */ 1281 mr = msm_read(port, MSM_UART_MR2); 1282 mr &= ~MSM_UART_MR2_PARITY_MODE; 1283 if (termios->c_cflag & PARENB) { 1284 if (termios->c_cflag & PARODD) 1285 mr |= MSM_UART_MR2_PARITY_MODE_ODD; 1286 else if (termios->c_cflag & CMSPAR) 1287 mr |= MSM_UART_MR2_PARITY_MODE_SPACE; 1288 else 1289 mr |= MSM_UART_MR2_PARITY_MODE_EVEN; 1290 } 1291 1292 /* calculate bits per char */ 1293 mr &= ~MSM_UART_MR2_BITS_PER_CHAR; 1294 switch (termios->c_cflag & CSIZE) { 1295 case CS5: 1296 mr |= MSM_UART_MR2_BITS_PER_CHAR_5; 1297 break; 1298 case CS6: 1299 mr |= MSM_UART_MR2_BITS_PER_CHAR_6; 1300 break; 1301 case CS7: 1302 mr |= MSM_UART_MR2_BITS_PER_CHAR_7; 1303 break; 1304 case CS8: 1305 default: 1306 mr |= MSM_UART_MR2_BITS_PER_CHAR_8; 1307 break; 1308 } 1309 1310 /* calculate stop bits */ 1311 mr &= ~(MSM_UART_MR2_STOP_BIT_LEN_ONE | MSM_UART_MR2_STOP_BIT_LEN_TWO); 1312 if (termios->c_cflag & CSTOPB) 1313 mr |= MSM_UART_MR2_STOP_BIT_LEN_TWO; 1314 else 1315 mr |= MSM_UART_MR2_STOP_BIT_LEN_ONE; 1316 1317 /* set parity, bits per char, and stop bit */ 1318 msm_write(port, mr, MSM_UART_MR2); 1319 1320 /* calculate and set hardware flow control */ 1321 mr = msm_read(port, MSM_UART_MR1); 1322 mr &= ~(MSM_UART_MR1_CTS_CTL | MSM_UART_MR1_RX_RDY_CTL); 1323 if (termios->c_cflag & CRTSCTS) { 1324 mr |= MSM_UART_MR1_CTS_CTL; 1325 mr |= MSM_UART_MR1_RX_RDY_CTL; 1326 } 1327 msm_write(port, mr, MSM_UART_MR1); 1328 1329 /* Configure status bits to ignore based on termio flags. */ 1330 port->read_status_mask = 0; 1331 if (termios->c_iflag & INPCK) 1332 port->read_status_mask |= MSM_UART_SR_PAR_FRAME_ERR; 1333 if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) 1334 port->read_status_mask |= MSM_UART_SR_RX_BREAK; 1335 1336 uart_update_timeout(port, termios->c_cflag, baud); 1337 1338 /* Try to use DMA */ 1339 msm_start_rx_dma(msm_port); 1340 1341 spin_unlock_irqrestore(&port->lock, flags); 1342 } 1343 1344 static const char *msm_type(struct uart_port *port) 1345 { 1346 return "MSM"; 1347 } 1348 1349 static void msm_release_port(struct uart_port *port) 1350 { 1351 struct platform_device *pdev = to_platform_device(port->dev); 1352 struct resource *uart_resource; 1353 resource_size_t size; 1354 1355 uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1356 if (unlikely(!uart_resource)) 1357 return; 1358 size = resource_size(uart_resource); 1359 1360 release_mem_region(port->mapbase, size); 1361 iounmap(port->membase); 1362 port->membase = NULL; 1363 } 1364 1365 static int msm_request_port(struct uart_port *port) 1366 { 1367 struct platform_device *pdev = to_platform_device(port->dev); 1368 struct resource *uart_resource; 1369 resource_size_t size; 1370 int ret; 1371 1372 uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1373 if (unlikely(!uart_resource)) 1374 return -ENXIO; 1375 1376 size = resource_size(uart_resource); 1377 1378 if (!request_mem_region(port->mapbase, size, "msm_serial")) 1379 return -EBUSY; 1380 1381 port->membase = ioremap(port->mapbase, size); 1382 if (!port->membase) { 1383 ret = -EBUSY; 1384 goto fail_release_port; 1385 } 1386 1387 return 0; 1388 1389 fail_release_port: 1390 release_mem_region(port->mapbase, size); 1391 return ret; 1392 } 1393 1394 static void msm_config_port(struct uart_port *port, int flags) 1395 { 1396 int ret; 1397 1398 if (flags & UART_CONFIG_TYPE) { 1399 port->type = PORT_MSM; 1400 ret = msm_request_port(port); 1401 if (ret) 1402 return; 1403 } 1404 } 1405 1406 static int msm_verify_port(struct uart_port *port, struct serial_struct *ser) 1407 { 1408 if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM)) 1409 return -EINVAL; 1410 if (unlikely(port->irq != ser->irq)) 1411 return -EINVAL; 1412 return 0; 1413 } 1414 1415 static void msm_power(struct uart_port *port, unsigned int state, 1416 unsigned int oldstate) 1417 { 1418 struct msm_port *msm_port = to_msm_port(port); 1419 1420 switch (state) { 1421 case 0: 1422 clk_prepare_enable(msm_port->clk); 1423 clk_prepare_enable(msm_port->pclk); 1424 break; 1425 case 3: 1426 clk_disable_unprepare(msm_port->clk); 1427 clk_disable_unprepare(msm_port->pclk); 1428 break; 1429 default: 1430 pr_err("msm_serial: Unknown PM state %d\n", state); 1431 } 1432 } 1433 1434 #ifdef CONFIG_CONSOLE_POLL 1435 static int msm_poll_get_char_single(struct uart_port *port) 1436 { 1437 struct msm_port *msm_port = to_msm_port(port); 1438 unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : MSM_UART_RF; 1439 1440 if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_RX_READY)) 1441 return NO_POLL_CHAR; 1442 1443 return msm_read(port, rf_reg) & 0xff; 1444 } 1445 1446 static int msm_poll_get_char_dm(struct uart_port *port) 1447 { 1448 int c; 1449 static u32 slop; 1450 static int count; 1451 unsigned char *sp = (unsigned char *)&slop; 1452 1453 /* Check if a previous read had more than one char */ 1454 if (count) { 1455 c = sp[sizeof(slop) - count]; 1456 count--; 1457 /* Or if FIFO is empty */ 1458 } else if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_RX_READY)) { 1459 /* 1460 * If RX packing buffer has less than a word, force stale to 1461 * push contents into RX FIFO 1462 */ 1463 count = msm_read(port, UARTDM_RXFS); 1464 count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK; 1465 if (count) { 1466 msm_write(port, MSM_UART_CR_CMD_FORCE_STALE, MSM_UART_CR); 1467 slop = msm_read(port, UARTDM_RF); 1468 c = sp[0]; 1469 count--; 1470 msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR); 1471 msm_write(port, 0xFFFFFF, UARTDM_DMRX); 1472 msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR); 1473 } else { 1474 c = NO_POLL_CHAR; 1475 } 1476 /* FIFO has a word */ 1477 } else { 1478 slop = msm_read(port, UARTDM_RF); 1479 c = sp[0]; 1480 count = sizeof(slop) - 1; 1481 } 1482 1483 return c; 1484 } 1485 1486 static int msm_poll_get_char(struct uart_port *port) 1487 { 1488 u32 imr; 1489 int c; 1490 struct msm_port *msm_port = to_msm_port(port); 1491 1492 /* Disable all interrupts */ 1493 imr = msm_read(port, MSM_UART_IMR); 1494 msm_write(port, 0, MSM_UART_IMR); 1495 1496 if (msm_port->is_uartdm) 1497 c = msm_poll_get_char_dm(port); 1498 else 1499 c = msm_poll_get_char_single(port); 1500 1501 /* Enable interrupts */ 1502 msm_write(port, imr, MSM_UART_IMR); 1503 1504 return c; 1505 } 1506 1507 static void msm_poll_put_char(struct uart_port *port, unsigned char c) 1508 { 1509 u32 imr; 1510 struct msm_port *msm_port = to_msm_port(port); 1511 1512 /* Disable all interrupts */ 1513 imr = msm_read(port, MSM_UART_IMR); 1514 msm_write(port, 0, MSM_UART_IMR); 1515 1516 if (msm_port->is_uartdm) 1517 msm_reset_dm_count(port, 1); 1518 1519 /* Wait until FIFO is empty */ 1520 while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY)) 1521 cpu_relax(); 1522 1523 /* Write a character */ 1524 msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : MSM_UART_TF); 1525 1526 /* Wait until FIFO is empty */ 1527 while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY)) 1528 cpu_relax(); 1529 1530 /* Enable interrupts */ 1531 msm_write(port, imr, MSM_UART_IMR); 1532 } 1533 #endif 1534 1535 static const struct uart_ops msm_uart_pops = { 1536 .tx_empty = msm_tx_empty, 1537 .set_mctrl = msm_set_mctrl, 1538 .get_mctrl = msm_get_mctrl, 1539 .stop_tx = msm_stop_tx, 1540 .start_tx = msm_start_tx, 1541 .stop_rx = msm_stop_rx, 1542 .enable_ms = msm_enable_ms, 1543 .break_ctl = msm_break_ctl, 1544 .startup = msm_startup, 1545 .shutdown = msm_shutdown, 1546 .set_termios = msm_set_termios, 1547 .type = msm_type, 1548 .release_port = msm_release_port, 1549 .request_port = msm_request_port, 1550 .config_port = msm_config_port, 1551 .verify_port = msm_verify_port, 1552 .pm = msm_power, 1553 #ifdef CONFIG_CONSOLE_POLL 1554 .poll_get_char = msm_poll_get_char, 1555 .poll_put_char = msm_poll_put_char, 1556 #endif 1557 }; 1558 1559 static struct msm_port msm_uart_ports[] = { 1560 { 1561 .uart = { 1562 .iotype = UPIO_MEM, 1563 .ops = &msm_uart_pops, 1564 .flags = UPF_BOOT_AUTOCONF, 1565 .fifosize = 64, 1566 .line = 0, 1567 }, 1568 }, 1569 { 1570 .uart = { 1571 .iotype = UPIO_MEM, 1572 .ops = &msm_uart_pops, 1573 .flags = UPF_BOOT_AUTOCONF, 1574 .fifosize = 64, 1575 .line = 1, 1576 }, 1577 }, 1578 { 1579 .uart = { 1580 .iotype = UPIO_MEM, 1581 .ops = &msm_uart_pops, 1582 .flags = UPF_BOOT_AUTOCONF, 1583 .fifosize = 64, 1584 .line = 2, 1585 }, 1586 }, 1587 }; 1588 1589 #define MSM_UART_NR ARRAY_SIZE(msm_uart_ports) 1590 1591 static inline struct uart_port *msm_get_port_from_line(unsigned int line) 1592 { 1593 return &msm_uart_ports[line].uart; 1594 } 1595 1596 #ifdef CONFIG_SERIAL_MSM_CONSOLE 1597 static void __msm_console_write(struct uart_port *port, const char *s, 1598 unsigned int count, bool is_uartdm) 1599 { 1600 unsigned long flags; 1601 int i; 1602 int num_newlines = 0; 1603 bool replaced = false; 1604 void __iomem *tf; 1605 int locked = 1; 1606 1607 if (is_uartdm) 1608 tf = port->membase + UARTDM_TF; 1609 else 1610 tf = port->membase + MSM_UART_TF; 1611 1612 /* Account for newlines that will get a carriage return added */ 1613 for (i = 0; i < count; i++) 1614 if (s[i] == '\n') 1615 num_newlines++; 1616 count += num_newlines; 1617 1618 local_irq_save(flags); 1619 1620 if (port->sysrq) 1621 locked = 0; 1622 else if (oops_in_progress) 1623 locked = spin_trylock(&port->lock); 1624 else 1625 spin_lock(&port->lock); 1626 1627 if (is_uartdm) 1628 msm_reset_dm_count(port, count); 1629 1630 i = 0; 1631 while (i < count) { 1632 int j; 1633 unsigned int num_chars; 1634 char buf[4] = { 0 }; 1635 1636 if (is_uartdm) 1637 num_chars = min(count - i, (unsigned int)sizeof(buf)); 1638 else 1639 num_chars = 1; 1640 1641 for (j = 0; j < num_chars; j++) { 1642 char c = *s; 1643 1644 if (c == '\n' && !replaced) { 1645 buf[j] = '\r'; 1646 j++; 1647 replaced = true; 1648 } 1649 if (j < num_chars) { 1650 buf[j] = c; 1651 s++; 1652 replaced = false; 1653 } 1654 } 1655 1656 while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY)) 1657 cpu_relax(); 1658 1659 iowrite32_rep(tf, buf, 1); 1660 i += num_chars; 1661 } 1662 1663 if (locked) 1664 spin_unlock(&port->lock); 1665 1666 local_irq_restore(flags); 1667 } 1668 1669 static void msm_console_write(struct console *co, const char *s, 1670 unsigned int count) 1671 { 1672 struct uart_port *port; 1673 struct msm_port *msm_port; 1674 1675 BUG_ON(co->index < 0 || co->index >= MSM_UART_NR); 1676 1677 port = msm_get_port_from_line(co->index); 1678 msm_port = to_msm_port(port); 1679 1680 __msm_console_write(port, s, count, msm_port->is_uartdm); 1681 } 1682 1683 static int msm_console_setup(struct console *co, char *options) 1684 { 1685 struct uart_port *port; 1686 int baud = 115200; 1687 int bits = 8; 1688 int parity = 'n'; 1689 int flow = 'n'; 1690 1691 if (unlikely(co->index >= MSM_UART_NR || co->index < 0)) 1692 return -ENXIO; 1693 1694 port = msm_get_port_from_line(co->index); 1695 1696 if (unlikely(!port->membase)) 1697 return -ENXIO; 1698 1699 msm_init_clock(port); 1700 1701 if (options) 1702 uart_parse_options(options, &baud, &parity, &bits, &flow); 1703 1704 pr_info("msm_serial: console setup on port #%d\n", port->line); 1705 1706 return uart_set_options(port, co, baud, parity, bits, flow); 1707 } 1708 1709 static void 1710 msm_serial_early_write(struct console *con, const char *s, unsigned n) 1711 { 1712 struct earlycon_device *dev = con->data; 1713 1714 __msm_console_write(&dev->port, s, n, false); 1715 } 1716 1717 static int __init 1718 msm_serial_early_console_setup(struct earlycon_device *device, const char *opt) 1719 { 1720 if (!device->port.membase) 1721 return -ENODEV; 1722 1723 device->con->write = msm_serial_early_write; 1724 return 0; 1725 } 1726 OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart", 1727 msm_serial_early_console_setup); 1728 1729 static void 1730 msm_serial_early_write_dm(struct console *con, const char *s, unsigned n) 1731 { 1732 struct earlycon_device *dev = con->data; 1733 1734 __msm_console_write(&dev->port, s, n, true); 1735 } 1736 1737 static int __init 1738 msm_serial_early_console_setup_dm(struct earlycon_device *device, 1739 const char *opt) 1740 { 1741 if (!device->port.membase) 1742 return -ENODEV; 1743 1744 device->con->write = msm_serial_early_write_dm; 1745 return 0; 1746 } 1747 OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm", 1748 msm_serial_early_console_setup_dm); 1749 1750 static struct uart_driver msm_uart_driver; 1751 1752 static struct console msm_console = { 1753 .name = "ttyMSM", 1754 .write = msm_console_write, 1755 .device = uart_console_device, 1756 .setup = msm_console_setup, 1757 .flags = CON_PRINTBUFFER, 1758 .index = -1, 1759 .data = &msm_uart_driver, 1760 }; 1761 1762 #define MSM_CONSOLE (&msm_console) 1763 1764 #else 1765 #define MSM_CONSOLE NULL 1766 #endif 1767 1768 static struct uart_driver msm_uart_driver = { 1769 .owner = THIS_MODULE, 1770 .driver_name = "msm_serial", 1771 .dev_name = "ttyMSM", 1772 .nr = MSM_UART_NR, 1773 .cons = MSM_CONSOLE, 1774 }; 1775 1776 static atomic_t msm_uart_next_id = ATOMIC_INIT(0); 1777 1778 static const struct of_device_id msm_uartdm_table[] = { 1779 { .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 }, 1780 { .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 }, 1781 { .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 }, 1782 { .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 }, 1783 { } 1784 }; 1785 1786 static int msm_serial_probe(struct platform_device *pdev) 1787 { 1788 struct msm_port *msm_port; 1789 struct resource *resource; 1790 struct uart_port *port; 1791 const struct of_device_id *id; 1792 int irq, line; 1793 1794 if (pdev->dev.of_node) 1795 line = of_alias_get_id(pdev->dev.of_node, "serial"); 1796 else 1797 line = pdev->id; 1798 1799 if (line < 0) 1800 line = atomic_inc_return(&msm_uart_next_id) - 1; 1801 1802 if (unlikely(line < 0 || line >= MSM_UART_NR)) 1803 return -ENXIO; 1804 1805 dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line); 1806 1807 port = msm_get_port_from_line(line); 1808 port->dev = &pdev->dev; 1809 msm_port = to_msm_port(port); 1810 1811 id = of_match_device(msm_uartdm_table, &pdev->dev); 1812 if (id) 1813 msm_port->is_uartdm = (unsigned long)id->data; 1814 else 1815 msm_port->is_uartdm = 0; 1816 1817 msm_port->clk = devm_clk_get(&pdev->dev, "core"); 1818 if (IS_ERR(msm_port->clk)) 1819 return PTR_ERR(msm_port->clk); 1820 1821 if (msm_port->is_uartdm) { 1822 msm_port->pclk = devm_clk_get(&pdev->dev, "iface"); 1823 if (IS_ERR(msm_port->pclk)) 1824 return PTR_ERR(msm_port->pclk); 1825 } 1826 1827 port->uartclk = clk_get_rate(msm_port->clk); 1828 dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk); 1829 1830 resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1831 if (unlikely(!resource)) 1832 return -ENXIO; 1833 port->mapbase = resource->start; 1834 1835 irq = platform_get_irq(pdev, 0); 1836 if (unlikely(irq < 0)) 1837 return -ENXIO; 1838 port->irq = irq; 1839 port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MSM_CONSOLE); 1840 1841 platform_set_drvdata(pdev, port); 1842 1843 return uart_add_one_port(&msm_uart_driver, port); 1844 } 1845 1846 static int msm_serial_remove(struct platform_device *pdev) 1847 { 1848 struct uart_port *port = platform_get_drvdata(pdev); 1849 1850 uart_remove_one_port(&msm_uart_driver, port); 1851 1852 return 0; 1853 } 1854 1855 static const struct of_device_id msm_match_table[] = { 1856 { .compatible = "qcom,msm-uart" }, 1857 { .compatible = "qcom,msm-uartdm" }, 1858 {} 1859 }; 1860 MODULE_DEVICE_TABLE(of, msm_match_table); 1861 1862 static int __maybe_unused msm_serial_suspend(struct device *dev) 1863 { 1864 struct msm_port *port = dev_get_drvdata(dev); 1865 1866 uart_suspend_port(&msm_uart_driver, &port->uart); 1867 1868 return 0; 1869 } 1870 1871 static int __maybe_unused msm_serial_resume(struct device *dev) 1872 { 1873 struct msm_port *port = dev_get_drvdata(dev); 1874 1875 uart_resume_port(&msm_uart_driver, &port->uart); 1876 1877 return 0; 1878 } 1879 1880 static const struct dev_pm_ops msm_serial_dev_pm_ops = { 1881 SET_SYSTEM_SLEEP_PM_OPS(msm_serial_suspend, msm_serial_resume) 1882 }; 1883 1884 static struct platform_driver msm_platform_driver = { 1885 .remove = msm_serial_remove, 1886 .probe = msm_serial_probe, 1887 .driver = { 1888 .name = "msm_serial", 1889 .pm = &msm_serial_dev_pm_ops, 1890 .of_match_table = msm_match_table, 1891 }, 1892 }; 1893 1894 static int __init msm_serial_init(void) 1895 { 1896 int ret; 1897 1898 ret = uart_register_driver(&msm_uart_driver); 1899 if (unlikely(ret)) 1900 return ret; 1901 1902 ret = platform_driver_register(&msm_platform_driver); 1903 if (unlikely(ret)) 1904 uart_unregister_driver(&msm_uart_driver); 1905 1906 pr_info("msm_serial: driver initialized\n"); 1907 1908 return ret; 1909 } 1910 1911 static void __exit msm_serial_exit(void) 1912 { 1913 platform_driver_unregister(&msm_platform_driver); 1914 uart_unregister_driver(&msm_uart_driver); 1915 } 1916 1917 module_init(msm_serial_init); 1918 module_exit(msm_serial_exit); 1919 1920 MODULE_AUTHOR("Robert Love <rlove@google.com>"); 1921 MODULE_DESCRIPTION("Driver for msm7x serial device"); 1922 MODULE_LICENSE("GPL"); 1923