drivers/tty/serial/8250/8250_mtk.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Mediatek 8250 driver.
   4  *
   5  * Copyright (c) 2014 MundoReader S.L.
   6  * Author: Matthias Brugger <matthias.bgg@gmail.com>
   7  */
   8 #include <linux/clk.h>
   9 #include <linux/io.h>
  10 #include <linux/module.h>
  11 #include <linux/of_irq.h>
  12 #include <linux/of_platform.h>
  13 #include <linux/pinctrl/consumer.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/pm_runtime.h>
  16 #include <linux/serial_8250.h>
  17 #include <linux/serial_reg.h>
  18 #include <linux/console.h>
  19 #include <linux/dma-mapping.h>
  20 #include <linux/tty.h>
  21 #include <linux/tty_flip.h>
  22
  23 #include "8250.h"
  24
  25 #define MTK_UART_HIGHS          0x09    /* Highspeed register */
  26 #define MTK_UART_SAMPLE_COUNT   0x0a    /* Sample count register */
  27 #define MTK_UART_SAMPLE_POINT   0x0b    /* Sample point register */
  28 #define MTK_UART_RATE_FIX       0x0d    /* UART Rate Fix Register */
  29 #define MTK_UART_ESCAPE_DAT     0x10    /* Escape Character register */
  30 #define MTK_UART_ESCAPE_EN      0x11    /* Escape Enable register */
  31 #define MTK_UART_DMA_EN         0x13    /* DMA Enable register */
  32 #define MTK_UART_RXTRI_AD       0x14    /* RX Trigger address */
  33 #define MTK_UART_FRACDIV_L      0x15    /* Fractional divider LSB address */
  34 #define MTK_UART_FRACDIV_M      0x16    /* Fractional divider MSB address */
  35 #define MTK_UART_IER_XOFFI      0x20    /* Enable XOFF character interrupt */
  36 #define MTK_UART_IER_RTSI       0x40    /* Enable RTS Modem status interrupt */
  37 #define MTK_UART_IER_CTSI       0x80    /* Enable CTS Modem status interrupt */
  38
  39 #define MTK_UART_EFR_EN         0x10    /* Enable enhancement feature */
  40 #define MTK_UART_EFR_RTS        0x40    /* Enable hardware rx flow control */
  41 #define MTK_UART_EFR_CTS        0x80    /* Enable hardware tx flow control */
  42 #define MTK_UART_EFR_NO_SW_FC   0x0     /* no sw flow control */
  43 #define MTK_UART_EFR_XON1_XOFF1 0xa     /* XON1/XOFF1 as sw flow control */
  44 #define MTK_UART_EFR_XON2_XOFF2 0x5     /* XON2/XOFF2 as sw flow control */
  45 #define MTK_UART_EFR_SW_FC_MASK 0xf     /* Enable CTS Modem status interrupt */
  46 #define MTK_UART_EFR_HW_FC      (MTK_UART_EFR_RTS | MTK_UART_EFR_CTS)
  47 #define MTK_UART_DMA_EN_TX      0x2
  48 #define MTK_UART_DMA_EN_RX      0x5
  49
  50 #define MTK_UART_ESCAPE_CHAR    0x77    /* Escape char added under sw fc */
  51 #define MTK_UART_RX_SIZE        0x8000
  52 #define MTK_UART_TX_TRIGGER     1
  53 #define MTK_UART_RX_TRIGGER     MTK_UART_RX_SIZE
  54
  55 #ifdef CONFIG_SERIAL_8250_DMA
  56 enum dma_rx_status {
  57         DMA_RX_START = 0,
  58         DMA_RX_RUNNING = 1,
  59         DMA_RX_SHUTDOWN = 2,
  60 };
  61 #endif
  62
  63 struct mtk8250_data {
  64         int                     line;
  65         unsigned int            rx_pos;
  66         unsigned int            clk_count;
  67         struct clk              *uart_clk;
  68         struct clk              *bus_clk;
  69         struct uart_8250_dma    *dma;
  70 #ifdef CONFIG_SERIAL_8250_DMA
  71         enum dma_rx_status      rx_status;
  72 #endif
  73         int                     rx_wakeup_irq;
  74 };
  75
  76 /* flow control mode */
  77 enum {
  78         MTK_UART_FC_NONE,
  79         MTK_UART_FC_SW,
  80         MTK_UART_FC_HW,
  81 };
  82
  83 #ifdef CONFIG_SERIAL_8250_DMA
  84 static void mtk8250_rx_dma(struct uart_8250_port *up);
  85
  86 static void mtk8250_dma_rx_complete(void *param)
  87 {
  88         struct uart_8250_port *up = param;
  89         struct uart_8250_dma *dma = up->dma;
  90         struct mtk8250_data *data = up->port.private_data;
  91         struct tty_port *tty_port = &up->port.state->port;
  92         struct dma_tx_state state;
  93         int copied, total, cnt;
  94         unsigned char *ptr;
  95
  96         if (data->rx_status == DMA_RX_SHUTDOWN)
  97                 return;
  98
  99         dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
 100         total = dma->rx_size - state.residue;
 101         cnt = total;
 102
 103         if ((data->rx_pos + cnt) > dma->rx_size)
 104                 cnt = dma->rx_size - data->rx_pos;
 105
 106         ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
 107         copied = tty_insert_flip_string(tty_port, ptr, cnt);
 108         data->rx_pos += cnt;
 109
 110         if (total > cnt) {
 111                 ptr = (unsigned char *)(dma->rx_buf);
 112                 cnt = total - cnt;
 113                 copied += tty_insert_flip_string(tty_port, ptr, cnt);
 114                 data->rx_pos = cnt;
 115         }
 116
 117         up->port.icount.rx += copied;
 118
 119         tty_flip_buffer_push(tty_port);
 120
 121         mtk8250_rx_dma(up);
 122 }
 123
 124 static void mtk8250_rx_dma(struct uart_8250_port *up)
 125 {
 126         struct uart_8250_dma *dma = up->dma;
 127         struct dma_async_tx_descriptor  *desc;
 128
 129         desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
 130                                            dma->rx_size, DMA_DEV_TO_MEM,
 131                                            DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 132         if (!desc) {
 133                 pr_err("failed to prepare rx slave single\n");
 134                 return;
 135         }
 136
 137         desc->callback = mtk8250_dma_rx_complete;
 138         desc->callback_param = up;
 139
 140         dma->rx_cookie = dmaengine_submit(desc);
 141
 142         dma_async_issue_pending(dma->rxchan);
 143 }
 144
 145 static void mtk8250_dma_enable(struct uart_8250_port *up)
 146 {
 147         struct uart_8250_dma *dma = up->dma;
 148         struct mtk8250_data *data = up->port.private_data;
 149         int lcr = serial_in(up, UART_LCR);
 150
 151         if (data->rx_status != DMA_RX_START)
 152                 return;
 153
 154         dma->rxconf.src_port_window_size        = dma->rx_size;
 155         dma->rxconf.src_addr                            = dma->rx_addr;
 156
 157         dma->txconf.dst_port_window_size        = UART_XMIT_SIZE;
 158         dma->txconf.dst_addr                            = dma->tx_addr;
 159
 160         serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
 161                 UART_FCR_CLEAR_XMIT);
 162         serial_out(up, MTK_UART_DMA_EN,
 163                    MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX);
 164
 165         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 166         serial_out(up, UART_EFR, UART_EFR_ECB);
 167         serial_out(up, UART_LCR, lcr);
 168
 169         if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0)
 170                 pr_err("failed to configure rx dma channel\n");
 171         if (dmaengine_slave_config(dma->txchan, &dma->txconf) != 0)
 172                 pr_err("failed to configure tx dma channel\n");
 173
 174         data->rx_status = DMA_RX_RUNNING;
 175         data->rx_pos = 0;
 176         mtk8250_rx_dma(up);
 177 }
 178 #endif
 179
 180 static int mtk8250_startup(struct uart_port *port)
 181 {
 182 #ifdef CONFIG_SERIAL_8250_DMA
 183         struct uart_8250_port *up = up_to_u8250p(port);
 184         struct mtk8250_data *data = port->private_data;
 185
 186         /* disable DMA for console */
 187         if (uart_console(port))
 188                 up->dma = NULL;
 189
 190         if (up->dma) {
 191                 data->rx_status = DMA_RX_START;
 192                 uart_circ_clear(&port->state->xmit);
 193         }
 194 #endif
 195         memset(&port->icount, 0, sizeof(port->icount));
 196
 197         return serial8250_do_startup(port);
 198 }
 199
 200 static void mtk8250_shutdown(struct uart_port *port)
 201 {
 202 #ifdef CONFIG_SERIAL_8250_DMA
 203         struct uart_8250_port *up = up_to_u8250p(port);
 204         struct mtk8250_data *data = port->private_data;
 205
 206         if (up->dma)
 207                 data->rx_status = DMA_RX_SHUTDOWN;
 208 #endif
 209
 210         return serial8250_do_shutdown(port);
 211 }
 212
 213 static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
 214 {
 215         serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));
 216 }
 217
 218 static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)
 219 {
 220         serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);
 221 }
 222
 223 static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
 224 {
 225         struct uart_port *port = &up->port;
 226         int lcr = serial_in(up, UART_LCR);
 227
 228         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 229         serial_out(up, UART_EFR, UART_EFR_ECB);
 230         serial_out(up, UART_LCR, lcr);
 231         lcr = serial_in(up, UART_LCR);
 232
 233         switch (mode) {
 234         case MTK_UART_FC_NONE:
 235                 serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
 236                 serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
 237                 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 238                 serial_out(up, UART_EFR, serial_in(up, UART_EFR) &
 239                         (~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK)));
 240                 serial_out(up, UART_LCR, lcr);
 241                 mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI |
 242                         MTK_UART_IER_RTSI | MTK_UART_IER_CTSI);
 243                 break;
 244
 245         case MTK_UART_FC_HW:
 246                 serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
 247                 serial_out(up, MTK_UART_ESCAPE_EN, 0x00);
 248                 serial_out(up, UART_MCR, UART_MCR_RTS);
 249                 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 250
 251                 /*enable hw flow control*/
 252                 serial_out(up, UART_EFR, MTK_UART_EFR_HW_FC |
 253                         (serial_in(up, UART_EFR) &
 254                         (~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));
 255
 256                 serial_out(up, UART_LCR, lcr);
 257                 mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI);
 258                 mtk8250_enable_intrs(up, MTK_UART_IER_CTSI | MTK_UART_IER_RTSI);
 259                 break;
 260
 261         case MTK_UART_FC_SW:    /*MTK software flow control */
 262                 serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR);
 263                 serial_out(up, MTK_UART_ESCAPE_EN, 0x01);
 264                 serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 265
 266                 /*enable sw flow control */
 267                 serial_out(up, UART_EFR, MTK_UART_EFR_XON1_XOFF1 |
 268                         (serial_in(up, UART_EFR) &
 269                         (~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))));
 270
 271                 serial_out(up, UART_XON1, START_CHAR(port->state->port.tty));
 272                 serial_out(up, UART_XOFF1, STOP_CHAR(port->state->port.tty));
 273                 serial_out(up, UART_LCR, lcr);
 274                 mtk8250_disable_intrs(up, MTK_UART_IER_CTSI|MTK_UART_IER_RTSI);
 275                 mtk8250_enable_intrs(up, MTK_UART_IER_XOFFI);
 276                 break;
 277         default:
 278                 break;
 279         }
 280 }
 281
 282 static void
 283 mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
 284                         struct ktermios *old)
 285 {
 286         unsigned short fraction_L_mapping[] = {
 287                 0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF
 288         };
 289         unsigned short fraction_M_mapping[] = {
 290                 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3
 291         };
 292         struct uart_8250_port *up = up_to_u8250p(port);
 293         unsigned int baud, quot, fraction;
 294         unsigned long flags;
 295         int mode;
 296
 297 #ifdef CONFIG_SERIAL_8250_DMA
 298         if (up->dma) {
 299                 if (uart_console(port)) {
 300                         devm_kfree(up->port.dev, up->dma);
 301                         up->dma = NULL;
 302                 } else {
 303                         mtk8250_dma_enable(up);
 304                 }
 305         }
 306 #endif
 307
 308         serial8250_do_set_termios(port, termios, old);
 309
 310         /*
 311          * Mediatek UARTs use an extra highspeed register (MTK_UART_HIGHS)
 312          *
 313          * We need to recalcualte the quot register, as the claculation depends
 314          * on the vaule in the highspeed register.
 315          *
 316          * Some baudrates are not supported by the chip, so we use the next
 317          * lower rate supported and update termios c_flag.
 318          *
 319          * If highspeed register is set to 3, we need to specify sample count
 320          * and sample point to increase accuracy. If not, we reset the
 321          * registers to their default values.
 322          */
 323         baud = uart_get_baud_rate(port, termios, old,
 324                                   port->uartclk / 16 / UART_DIV_MAX,
 325                                   port->uartclk);
 326
 327         if (baud < 115200) {
 328                 serial_port_out(port, MTK_UART_HIGHS, 0x0);
 329                 quot = uart_get_divisor(port, baud);
 330         } else {
 331                 serial_port_out(port, MTK_UART_HIGHS, 0x3);
 332                 quot = DIV_ROUND_UP(port->uartclk, 256 * baud);
 333         }
 334
 335         /*
 336          * Ok, we're now changing the port state.  Do it with
 337          * interrupts disabled.
 338          */
 339         spin_lock_irqsave(&port->lock, flags);
 340
 341         /* set DLAB we have cval saved in up->lcr from the call to the core */
 342         serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB);
 343         serial_dl_write(up, quot);
 344
 345         /* reset DLAB */
 346         serial_port_out(port, UART_LCR, up->lcr);
 347
 348         if (baud >= 115200) {
 349                 unsigned int tmp;
 350
 351                 tmp = (port->uartclk / (baud *  quot)) - 1;
 352                 serial_port_out(port, MTK_UART_SAMPLE_COUNT, tmp);
 353                 serial_port_out(port, MTK_UART_SAMPLE_POINT,
 354                                         (tmp >> 1) - 1);
 355
 356                 /*count fraction to set fractoin register */
 357                 fraction = ((port->uartclk  * 100) / baud / quot) % 100;
 358                 fraction = DIV_ROUND_CLOSEST(fraction, 10);
 359                 serial_port_out(port, MTK_UART_FRACDIV_L,
 360                                                 fraction_L_mapping[fraction]);
 361                 serial_port_out(port, MTK_UART_FRACDIV_M,
 362                                                 fraction_M_mapping[fraction]);
 363         } else {
 364                 serial_port_out(port, MTK_UART_SAMPLE_COUNT, 0x00);
 365                 serial_port_out(port, MTK_UART_SAMPLE_POINT, 0xff);
 366                 serial_port_out(port, MTK_UART_FRACDIV_L, 0x00);
 367                 serial_port_out(port, MTK_UART_FRACDIV_M, 0x00);
 368         }
 369
 370         if ((termios->c_cflag & CRTSCTS) && (!(termios->c_iflag & CRTSCTS)))
 371                 mode = MTK_UART_FC_HW;
 372         else if (termios->c_iflag & CRTSCTS)
 373                 mode = MTK_UART_FC_SW;
 374         else
 375                 mode = MTK_UART_FC_NONE;
 376
 377         mtk8250_set_flow_ctrl(up, mode);
 378
 379         if (uart_console(port))
 380                 up->port.cons->cflag = termios->c_cflag;
 381
 382         spin_unlock_irqrestore(&port->lock, flags);
 383         /* Don't rewrite B0 */
 384         if (tty_termios_baud_rate(termios))
 385                 tty_termios_encode_baud_rate(termios, baud, baud);
 386 }
 387
 388 static int __maybe_unused mtk8250_runtime_suspend(struct device *dev)
 389 {
 390         struct mtk8250_data *data = dev_get_drvdata(dev);
 391
 392         clk_disable_unprepare(data->uart_clk);
 393         clk_disable_unprepare(data->bus_clk);
 394
 395         return 0;
 396 }
 397
 398 static int __maybe_unused mtk8250_runtime_resume(struct device *dev)
 399 {
 400         struct mtk8250_data *data = dev_get_drvdata(dev);
 401         int err;
 402
 403         err = clk_prepare_enable(data->uart_clk);
 404         if (err) {
 405                 dev_warn(dev, "Can't enable clock\n");
 406                 return err;
 407         }
 408
 409         err = clk_prepare_enable(data->bus_clk);
 410         if (err) {
 411                 dev_warn(dev, "Can't enable bus clock\n");
 412                 return err;
 413         }
 414
 415         return 0;
 416 }
 417
 418 static void
 419 mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
 420 {
 421         if (!state)
 422                 pm_runtime_get_sync(port->dev);
 423
 424         serial8250_do_pm(port, state, old);
 425
 426         if (state)
 427                 pm_runtime_put_sync_suspend(port->dev);
 428 }
 429
 430 #ifdef CONFIG_SERIAL_8250_DMA
 431 static bool mtk8250_dma_filter(struct dma_chan *chan, void *param)
 432 {
 433         return false;
 434 }
 435 #endif
 436
 437 static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
 438                            struct mtk8250_data *data)
 439 {
 440 #ifdef CONFIG_SERIAL_8250_DMA
 441         int dmacnt;
 442 #endif
 443
 444         data->uart_clk = devm_clk_get(&pdev->dev, "baud");
 445         if (IS_ERR(data->uart_clk)) {
 446                 /*
 447                  * For compatibility with older device trees try unnamed
 448                  * clk when no baud clk can be found.
 449                  */
 450                 data->uart_clk = devm_clk_get(&pdev->dev, NULL);
 451                 if (IS_ERR(data->uart_clk)) {
 452                         dev_warn(&pdev->dev, "Can't get uart clock\n");
 453                         return PTR_ERR(data->uart_clk);
 454                 }
 455
 456                 return 0;
 457         }
 458
 459         data->bus_clk = devm_clk_get(&pdev->dev, "bus");
 460         if (IS_ERR(data->bus_clk))
 461                 return PTR_ERR(data->bus_clk);
 462
 463         data->dma = NULL;
 464 #ifdef CONFIG_SERIAL_8250_DMA
 465         dmacnt = of_property_count_strings(pdev->dev.of_node, "dma-names");
 466         if (dmacnt == 2) {
 467                 data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma),
 468                                          GFP_KERNEL);
 469                 if (!data->dma)
 470                         return -ENOMEM;
 471
 472                 data->dma->fn = mtk8250_dma_filter;
 473                 data->dma->rx_size = MTK_UART_RX_SIZE;
 474                 data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER;
 475                 data->dma->txconf.dst_maxburst = MTK_UART_TX_TRIGGER;
 476         }
 477 #endif
 478
 479         return 0;
 480 }
 481
 482 static int mtk8250_probe(struct platform_device *pdev)
 483 {
 484         struct uart_8250_port uart = {};
 485         struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 486         struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 487         struct mtk8250_data *data;
 488         int err;
 489
 490         if (!regs || !irq) {
 491                 dev_err(&pdev->dev, "no registers/irq defined\n");
 492                 return -EINVAL;
 493         }
 494
 495         uart.port.membase = devm_ioremap(&pdev->dev, regs->start,
 496                                          resource_size(regs));
 497         if (!uart.port.membase)
 498                 return -ENOMEM;
 499
 500         data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 501         if (!data)
 502                 return -ENOMEM;
 503
 504         if (pdev->dev.of_node) {
 505                 err = mtk8250_probe_of(pdev, &uart.port, data);
 506                 if (err)
 507                         return err;
 508         } else
 509                 return -ENODEV;
 510
 511         spin_lock_init(&uart.port.lock);
 512         uart.port.mapbase = regs->start;
 513         uart.port.irq = irq->start;
 514         uart.port.pm = mtk8250_do_pm;
 515         uart.port.type = PORT_16550;
 516         uart.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
 517         uart.port.dev = &pdev->dev;
 518         uart.port.iotype = UPIO_MEM32;
 519         uart.port.regshift = 2;
 520         uart.port.private_data = data;
 521         uart.port.shutdown = mtk8250_shutdown;
 522         uart.port.startup = mtk8250_startup;
 523         uart.port.set_termios = mtk8250_set_termios;
 524         uart.port.uartclk = clk_get_rate(data->uart_clk);
 525 #ifdef CONFIG_SERIAL_8250_DMA
 526         if (data->dma)
 527                 uart.dma = data->dma;
 528 #endif
 529
 530         /* Disable Rate Fix function */
 531         writel(0x0, uart.port.membase +
 532                         (MTK_UART_RATE_FIX << uart.port.regshift));
 533
 534         platform_set_drvdata(pdev, data);
 535
 536         err = mtk8250_runtime_resume(&pdev->dev);
 537         if (err)
 538                 return err;
 539
 540         data->line = serial8250_register_8250_port(&uart);
 541         if (data->line < 0)
 542                 return data->line;
 543
 544         pm_runtime_set_active(&pdev->dev);
 545         pm_runtime_enable(&pdev->dev);
 546
 547         data->rx_wakeup_irq = platform_get_irq(pdev, 1);
 548
 549         return 0;
 550 }
 551
 552 static int mtk8250_remove(struct platform_device *pdev)
 553 {
 554         struct mtk8250_data *data = platform_get_drvdata(pdev);
 555
 556         pm_runtime_get_sync(&pdev->dev);
 557
 558         serial8250_unregister_port(data->line);
 559         mtk8250_runtime_suspend(&pdev->dev);
 560
 561         pm_runtime_disable(&pdev->dev);
 562         pm_runtime_put_noidle(&pdev->dev);
 563
 564         return 0;
 565 }
 566
 567 static int __maybe_unused mtk8250_suspend(struct device *dev)
 568 {
 569         struct mtk8250_data *data = dev_get_drvdata(dev);
 570         int irq = data->rx_wakeup_irq;
 571         int err;
 572
 573         serial8250_suspend_port(data->line);
 574
 575         pinctrl_pm_select_sleep_state(dev);
 576         if (irq >= 0) {
 577                 err = enable_irq_wake(irq);
 578                 if (err) {
 579                         dev_err(dev,
 580                                 "failed to enable irq wake on IRQ %d: %d\n",
 581                                 irq, err);
 582                         pinctrl_pm_select_default_state(dev);
 583                         serial8250_resume_port(data->line);
 584                         return err;
 585                 }
 586         }
 587
 588         return 0;
 589 }
 590
 591 static int __maybe_unused mtk8250_resume(struct device *dev)
 592 {
 593         struct mtk8250_data *data = dev_get_drvdata(dev);
 594         int irq = data->rx_wakeup_irq;
 595
 596         if (irq >= 0)
 597                 disable_irq_wake(irq);
 598         pinctrl_pm_select_default_state(dev);
 599
 600         serial8250_resume_port(data->line);
 601
 602         return 0;
 603 }
 604
 605 static const struct dev_pm_ops mtk8250_pm_ops = {
 606         SET_SYSTEM_SLEEP_PM_OPS(mtk8250_suspend, mtk8250_resume)
 607         SET_RUNTIME_PM_OPS(mtk8250_runtime_suspend, mtk8250_runtime_resume,
 608                                 NULL)
 609 };
 610
 611 static const struct of_device_id mtk8250_of_match[] = {
 612         { .compatible = "mediatek,mt6577-uart" },
 613         { /* Sentinel */ }
 614 };
 615 MODULE_DEVICE_TABLE(of, mtk8250_of_match);
 616
 617 static struct platform_driver mtk8250_platform_driver = {
 618         .driver = {
 619                 .name           = "mt6577-uart",
 620                 .pm             = &mtk8250_pm_ops,
 621                 .of_match_table = mtk8250_of_match,
 622         },
 623         .probe                  = mtk8250_probe,
 624         .remove                 = mtk8250_remove,
 625 };
 626 module_platform_driver(mtk8250_platform_driver);
 627
 628 #ifdef CONFIG_SERIAL_8250_CONSOLE
 629 static int __init early_mtk8250_setup(struct earlycon_device *device,
 630                                         const char *options)
 631 {
 632         if (!device->port.membase)
 633                 return -ENODEV;
 634
 635         device->port.iotype = UPIO_MEM32;
 636
 637         return early_serial8250_setup(device, NULL);
 638 }
 639
 640 OF_EARLYCON_DECLARE(mtk8250, "mediatek,mt6577-uart", early_mtk8250_setup);
 641 #endif
 642
 643 MODULE_AUTHOR("Matthias Brugger");
 644 MODULE_LICENSE("GPL");
 645 MODULE_DESCRIPTION("Mediatek 8250 serial port driver");