Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 1 | /* |
| 2 | * st-asc.c: ST Asynchronous serial controller (ASC) driver |
| 3 | * |
| 4 | * Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #if defined(CONFIG_SERIAL_ST_ASC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) |
| 14 | #define SUPPORT_SYSRQ |
| 15 | #endif |
| 16 | |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/serial.h> |
| 19 | #include <linux/console.h> |
| 20 | #include <linux/sysrq.h> |
| 21 | #include <linux/platform_device.h> |
| 22 | #include <linux/io.h> |
| 23 | #include <linux/irq.h> |
| 24 | #include <linux/tty.h> |
| 25 | #include <linux/tty_flip.h> |
| 26 | #include <linux/delay.h> |
| 27 | #include <linux/spinlock.h> |
| 28 | #include <linux/pm_runtime.h> |
| 29 | #include <linux/of.h> |
| 30 | #include <linux/of_platform.h> |
| 31 | #include <linux/serial_core.h> |
| 32 | #include <linux/clk.h> |
| 33 | |
| 34 | #define DRIVER_NAME "st-asc" |
| 35 | #define ASC_SERIAL_NAME "ttyAS" |
| 36 | #define ASC_FIFO_SIZE 16 |
| 37 | #define ASC_MAX_PORTS 8 |
| 38 | |
| 39 | struct asc_port { |
| 40 | struct uart_port port; |
| 41 | struct clk *clk; |
| 42 | unsigned int hw_flow_control:1; |
| 43 | unsigned int force_m1:1; |
| 44 | }; |
| 45 | |
| 46 | static struct asc_port asc_ports[ASC_MAX_PORTS]; |
| 47 | static struct uart_driver asc_uart_driver; |
| 48 | |
| 49 | /*---- UART Register definitions ------------------------------*/ |
| 50 | |
| 51 | /* Register offsets */ |
| 52 | |
| 53 | #define ASC_BAUDRATE 0x00 |
| 54 | #define ASC_TXBUF 0x04 |
| 55 | #define ASC_RXBUF 0x08 |
| 56 | #define ASC_CTL 0x0C |
| 57 | #define ASC_INTEN 0x10 |
| 58 | #define ASC_STA 0x14 |
| 59 | #define ASC_GUARDTIME 0x18 |
| 60 | #define ASC_TIMEOUT 0x1C |
| 61 | #define ASC_TXRESET 0x20 |
| 62 | #define ASC_RXRESET 0x24 |
| 63 | #define ASC_RETRIES 0x28 |
| 64 | |
| 65 | /* ASC_RXBUF */ |
| 66 | #define ASC_RXBUF_PE 0x100 |
| 67 | #define ASC_RXBUF_FE 0x200 |
| 68 | /** |
| 69 | * Some of status comes from higher bits of the character and some come from |
| 70 | * the status register. Combining both of them in to single status using dummy |
| 71 | * bits. |
| 72 | */ |
| 73 | #define ASC_RXBUF_DUMMY_RX 0x10000 |
| 74 | #define ASC_RXBUF_DUMMY_BE 0x20000 |
| 75 | #define ASC_RXBUF_DUMMY_OE 0x40000 |
| 76 | |
| 77 | /* ASC_CTL */ |
| 78 | |
| 79 | #define ASC_CTL_MODE_MSK 0x0007 |
| 80 | #define ASC_CTL_MODE_8BIT 0x0001 |
| 81 | #define ASC_CTL_MODE_7BIT_PAR 0x0003 |
| 82 | #define ASC_CTL_MODE_9BIT 0x0004 |
| 83 | #define ASC_CTL_MODE_8BIT_WKUP 0x0005 |
| 84 | #define ASC_CTL_MODE_8BIT_PAR 0x0007 |
| 85 | #define ASC_CTL_STOP_MSK 0x0018 |
| 86 | #define ASC_CTL_STOP_HALFBIT 0x0000 |
| 87 | #define ASC_CTL_STOP_1BIT 0x0008 |
| 88 | #define ASC_CTL_STOP_1_HALFBIT 0x0010 |
| 89 | #define ASC_CTL_STOP_2BIT 0x0018 |
| 90 | #define ASC_CTL_PARITYODD 0x0020 |
| 91 | #define ASC_CTL_LOOPBACK 0x0040 |
| 92 | #define ASC_CTL_RUN 0x0080 |
| 93 | #define ASC_CTL_RXENABLE 0x0100 |
| 94 | #define ASC_CTL_SCENABLE 0x0200 |
| 95 | #define ASC_CTL_FIFOENABLE 0x0400 |
| 96 | #define ASC_CTL_CTSENABLE 0x0800 |
| 97 | #define ASC_CTL_BAUDMODE 0x1000 |
| 98 | |
| 99 | /* ASC_GUARDTIME */ |
| 100 | |
| 101 | #define ASC_GUARDTIME_MSK 0x00FF |
| 102 | |
| 103 | /* ASC_INTEN */ |
| 104 | |
| 105 | #define ASC_INTEN_RBE 0x0001 |
| 106 | #define ASC_INTEN_TE 0x0002 |
| 107 | #define ASC_INTEN_THE 0x0004 |
| 108 | #define ASC_INTEN_PE 0x0008 |
| 109 | #define ASC_INTEN_FE 0x0010 |
| 110 | #define ASC_INTEN_OE 0x0020 |
| 111 | #define ASC_INTEN_TNE 0x0040 |
| 112 | #define ASC_INTEN_TOI 0x0080 |
| 113 | #define ASC_INTEN_RHF 0x0100 |
| 114 | |
| 115 | /* ASC_RETRIES */ |
| 116 | |
| 117 | #define ASC_RETRIES_MSK 0x00FF |
| 118 | |
| 119 | /* ASC_RXBUF */ |
| 120 | |
| 121 | #define ASC_RXBUF_MSK 0x03FF |
| 122 | |
| 123 | /* ASC_STA */ |
| 124 | |
| 125 | #define ASC_STA_RBF 0x0001 |
| 126 | #define ASC_STA_TE 0x0002 |
| 127 | #define ASC_STA_THE 0x0004 |
| 128 | #define ASC_STA_PE 0x0008 |
| 129 | #define ASC_STA_FE 0x0010 |
| 130 | #define ASC_STA_OE 0x0020 |
| 131 | #define ASC_STA_TNE 0x0040 |
| 132 | #define ASC_STA_TOI 0x0080 |
| 133 | #define ASC_STA_RHF 0x0100 |
| 134 | #define ASC_STA_TF 0x0200 |
| 135 | #define ASC_STA_NKD 0x0400 |
| 136 | |
| 137 | /* ASC_TIMEOUT */ |
| 138 | |
| 139 | #define ASC_TIMEOUT_MSK 0x00FF |
| 140 | |
| 141 | /* ASC_TXBUF */ |
| 142 | |
| 143 | #define ASC_TXBUF_MSK 0x01FF |
| 144 | |
| 145 | /*---- Inline function definitions ---------------------------*/ |
| 146 | |
| 147 | static inline struct asc_port *to_asc_port(struct uart_port *port) |
| 148 | { |
| 149 | return container_of(port, struct asc_port, port); |
| 150 | } |
| 151 | |
| 152 | static inline u32 asc_in(struct uart_port *port, u32 offset) |
| 153 | { |
Daniel Thompson | daea65a | 2014-09-23 08:31:30 +0100 | [diff] [blame] | 154 | #ifdef readl_relaxed |
Daniel Thompson | 08177ec | 2014-09-09 11:03:57 +0100 | [diff] [blame] | 155 | return readl_relaxed(port->membase + offset); |
Daniel Thompson | daea65a | 2014-09-23 08:31:30 +0100 | [diff] [blame] | 156 | #else |
| 157 | return readl(port->membase + offset); |
| 158 | #endif |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 159 | } |
| 160 | |
| 161 | static inline void asc_out(struct uart_port *port, u32 offset, u32 value) |
| 162 | { |
Daniel Thompson | 08177ec | 2014-09-09 11:03:57 +0100 | [diff] [blame] | 163 | #ifdef writel_relaxed |
| 164 | writel_relaxed(value, port->membase + offset); |
| 165 | #else |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 166 | writel(value, port->membase + offset); |
Daniel Thompson | 08177ec | 2014-09-09 11:03:57 +0100 | [diff] [blame] | 167 | #endif |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 168 | } |
| 169 | |
| 170 | /* |
| 171 | * Some simple utility functions to enable and disable interrupts. |
| 172 | * Note that these need to be called with interrupts disabled. |
| 173 | */ |
| 174 | static inline void asc_disable_tx_interrupts(struct uart_port *port) |
| 175 | { |
| 176 | u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_THE; |
| 177 | asc_out(port, ASC_INTEN, intenable); |
| 178 | (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ |
| 179 | } |
| 180 | |
| 181 | static inline void asc_enable_tx_interrupts(struct uart_port *port) |
| 182 | { |
| 183 | u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_THE; |
| 184 | asc_out(port, ASC_INTEN, intenable); |
| 185 | } |
| 186 | |
| 187 | static inline void asc_disable_rx_interrupts(struct uart_port *port) |
| 188 | { |
| 189 | u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_RBE; |
| 190 | asc_out(port, ASC_INTEN, intenable); |
| 191 | (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ |
| 192 | } |
| 193 | |
| 194 | static inline void asc_enable_rx_interrupts(struct uart_port *port) |
| 195 | { |
| 196 | u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_RBE; |
| 197 | asc_out(port, ASC_INTEN, intenable); |
| 198 | } |
| 199 | |
| 200 | static inline u32 asc_txfifo_is_empty(struct uart_port *port) |
| 201 | { |
| 202 | return asc_in(port, ASC_STA) & ASC_STA_TE; |
| 203 | } |
| 204 | |
Daniel Thompson | 1ffcd67 | 2014-05-13 17:08:57 +0100 | [diff] [blame] | 205 | static inline u32 asc_txfifo_is_half_empty(struct uart_port *port) |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 206 | { |
Daniel Thompson | 1ffcd67 | 2014-05-13 17:08:57 +0100 | [diff] [blame] | 207 | return asc_in(port, ASC_STA) & ASC_STA_THE; |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 208 | } |
| 209 | |
| 210 | static inline const char *asc_port_name(struct uart_port *port) |
| 211 | { |
| 212 | return to_platform_device(port->dev)->name; |
| 213 | } |
| 214 | |
| 215 | /*----------------------------------------------------------------------*/ |
| 216 | |
| 217 | /* |
| 218 | * This section contains code to support the use of the ASC as a |
| 219 | * generic serial port. |
| 220 | */ |
| 221 | |
| 222 | static inline unsigned asc_hw_txroom(struct uart_port *port) |
| 223 | { |
| 224 | u32 status = asc_in(port, ASC_STA); |
| 225 | |
| 226 | if (status & ASC_STA_THE) |
| 227 | return port->fifosize / 2; |
| 228 | else if (!(status & ASC_STA_TF)) |
| 229 | return 1; |
| 230 | |
| 231 | return 0; |
| 232 | } |
| 233 | |
| 234 | /* |
| 235 | * Start transmitting chars. |
| 236 | * This is called from both interrupt and task level. |
| 237 | * Either way interrupts are disabled. |
| 238 | */ |
| 239 | static void asc_transmit_chars(struct uart_port *port) |
| 240 | { |
| 241 | struct circ_buf *xmit = &port->state->xmit; |
| 242 | int txroom; |
| 243 | unsigned char c; |
| 244 | |
| 245 | txroom = asc_hw_txroom(port); |
| 246 | |
| 247 | if ((txroom != 0) && port->x_char) { |
| 248 | c = port->x_char; |
| 249 | port->x_char = 0; |
| 250 | asc_out(port, ASC_TXBUF, c); |
| 251 | port->icount.tx++; |
| 252 | txroom = asc_hw_txroom(port); |
| 253 | } |
| 254 | |
| 255 | if (uart_tx_stopped(port)) { |
| 256 | /* |
| 257 | * We should try and stop the hardware here, but I |
| 258 | * don't think the ASC has any way to do that. |
| 259 | */ |
| 260 | asc_disable_tx_interrupts(port); |
| 261 | return; |
| 262 | } |
| 263 | |
| 264 | if (uart_circ_empty(xmit)) { |
| 265 | asc_disable_tx_interrupts(port); |
| 266 | return; |
| 267 | } |
| 268 | |
| 269 | if (txroom == 0) |
| 270 | return; |
| 271 | |
| 272 | do { |
| 273 | c = xmit->buf[xmit->tail]; |
| 274 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); |
| 275 | asc_out(port, ASC_TXBUF, c); |
| 276 | port->icount.tx++; |
| 277 | txroom--; |
| 278 | } while ((txroom > 0) && (!uart_circ_empty(xmit))); |
| 279 | |
| 280 | if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) |
| 281 | uart_write_wakeup(port); |
| 282 | |
| 283 | if (uart_circ_empty(xmit)) |
| 284 | asc_disable_tx_interrupts(port); |
| 285 | } |
| 286 | |
| 287 | static void asc_receive_chars(struct uart_port *port) |
| 288 | { |
| 289 | struct tty_port *tport = &port->state->port; |
| 290 | unsigned long status; |
| 291 | unsigned long c = 0; |
| 292 | char flag; |
| 293 | |
| 294 | if (port->irq_wake) |
| 295 | pm_wakeup_event(tport->tty->dev, 0); |
| 296 | |
| 297 | while ((status = asc_in(port, ASC_STA)) & ASC_STA_RBF) { |
| 298 | c = asc_in(port, ASC_RXBUF) | ASC_RXBUF_DUMMY_RX; |
| 299 | flag = TTY_NORMAL; |
| 300 | port->icount.rx++; |
| 301 | |
| 302 | if ((c & (ASC_RXBUF_FE | ASC_RXBUF_PE)) || |
| 303 | status & ASC_STA_OE) { |
| 304 | |
| 305 | if (c & ASC_RXBUF_FE) { |
Daniel Thompson | c3c00b6 | 2014-03-28 10:53:10 +0000 | [diff] [blame] | 306 | if (c == (ASC_RXBUF_FE | ASC_RXBUF_DUMMY_RX)) { |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 307 | port->icount.brk++; |
| 308 | if (uart_handle_break(port)) |
| 309 | continue; |
| 310 | c |= ASC_RXBUF_DUMMY_BE; |
| 311 | } else { |
| 312 | port->icount.frame++; |
| 313 | } |
| 314 | } else if (c & ASC_RXBUF_PE) { |
| 315 | port->icount.parity++; |
| 316 | } |
| 317 | /* |
| 318 | * Reading any data from the RX FIFO clears the |
| 319 | * overflow error condition. |
| 320 | */ |
| 321 | if (status & ASC_STA_OE) { |
| 322 | port->icount.overrun++; |
| 323 | c |= ASC_RXBUF_DUMMY_OE; |
| 324 | } |
| 325 | |
| 326 | c &= port->read_status_mask; |
| 327 | |
| 328 | if (c & ASC_RXBUF_DUMMY_BE) |
| 329 | flag = TTY_BREAK; |
| 330 | else if (c & ASC_RXBUF_PE) |
| 331 | flag = TTY_PARITY; |
| 332 | else if (c & ASC_RXBUF_FE) |
| 333 | flag = TTY_FRAME; |
| 334 | } |
| 335 | |
Daniel Thompson | c3c00b6 | 2014-03-28 10:53:10 +0000 | [diff] [blame] | 336 | if (uart_handle_sysrq_char(port, c & 0xff)) |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 337 | continue; |
| 338 | |
| 339 | uart_insert_char(port, c, ASC_RXBUF_DUMMY_OE, c & 0xff, flag); |
| 340 | } |
| 341 | |
| 342 | /* Tell the rest of the system the news. New characters! */ |
| 343 | tty_flip_buffer_push(tport); |
| 344 | } |
| 345 | |
| 346 | static irqreturn_t asc_interrupt(int irq, void *ptr) |
| 347 | { |
| 348 | struct uart_port *port = ptr; |
| 349 | u32 status; |
| 350 | |
| 351 | spin_lock(&port->lock); |
| 352 | |
| 353 | status = asc_in(port, ASC_STA); |
| 354 | |
| 355 | if (status & ASC_STA_RBF) { |
| 356 | /* Receive FIFO not empty */ |
| 357 | asc_receive_chars(port); |
| 358 | } |
| 359 | |
| 360 | if ((status & ASC_STA_THE) && |
| 361 | (asc_in(port, ASC_INTEN) & ASC_INTEN_THE)) { |
| 362 | /* Transmitter FIFO at least half empty */ |
| 363 | asc_transmit_chars(port); |
| 364 | } |
| 365 | |
| 366 | spin_unlock(&port->lock); |
| 367 | |
| 368 | return IRQ_HANDLED; |
| 369 | } |
| 370 | |
| 371 | /*----------------------------------------------------------------------*/ |
| 372 | |
| 373 | /* |
| 374 | * UART Functions |
| 375 | */ |
| 376 | |
| 377 | static unsigned int asc_tx_empty(struct uart_port *port) |
| 378 | { |
| 379 | return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0; |
| 380 | } |
| 381 | |
| 382 | static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl) |
| 383 | { |
| 384 | /* |
| 385 | * This routine is used for seting signals of: DTR, DCD, CTS/RTS |
| 386 | * We use ASC's hardware for CTS/RTS, so don't need any for that. |
| 387 | * Some boards have DTR and DCD implemented using PIO pins, |
| 388 | * code to do this should be hooked in here. |
| 389 | */ |
| 390 | } |
| 391 | |
| 392 | static unsigned int asc_get_mctrl(struct uart_port *port) |
| 393 | { |
| 394 | /* |
| 395 | * This routine is used for geting signals of: DTR, DCD, DSR, RI, |
| 396 | * and CTS/RTS |
| 397 | */ |
| 398 | return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; |
| 399 | } |
| 400 | |
| 401 | /* There are probably characters waiting to be transmitted. */ |
| 402 | static void asc_start_tx(struct uart_port *port) |
| 403 | { |
| 404 | struct circ_buf *xmit = &port->state->xmit; |
| 405 | |
| 406 | if (!uart_circ_empty(xmit)) |
| 407 | asc_enable_tx_interrupts(port); |
| 408 | } |
| 409 | |
| 410 | /* Transmit stop */ |
| 411 | static void asc_stop_tx(struct uart_port *port) |
| 412 | { |
| 413 | asc_disable_tx_interrupts(port); |
| 414 | } |
| 415 | |
| 416 | /* Receive stop */ |
| 417 | static void asc_stop_rx(struct uart_port *port) |
| 418 | { |
| 419 | asc_disable_rx_interrupts(port); |
| 420 | } |
| 421 | |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 422 | /* Handle breaks - ignored by us */ |
| 423 | static void asc_break_ctl(struct uart_port *port, int break_state) |
| 424 | { |
| 425 | /* Nothing here yet .. */ |
| 426 | } |
| 427 | |
| 428 | /* |
| 429 | * Enable port for reception. |
| 430 | */ |
| 431 | static int asc_startup(struct uart_port *port) |
| 432 | { |
Sudeep Holla | 616ea8d | 2015-09-21 16:47:06 +0100 | [diff] [blame] | 433 | if (request_irq(port->irq, asc_interrupt, 0, |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 434 | asc_port_name(port), port)) { |
| 435 | dev_err(port->dev, "cannot allocate irq.\n"); |
| 436 | return -ENODEV; |
| 437 | } |
| 438 | |
| 439 | asc_transmit_chars(port); |
| 440 | asc_enable_rx_interrupts(port); |
| 441 | |
| 442 | return 0; |
| 443 | } |
| 444 | |
| 445 | static void asc_shutdown(struct uart_port *port) |
| 446 | { |
| 447 | asc_disable_tx_interrupts(port); |
| 448 | asc_disable_rx_interrupts(port); |
| 449 | free_irq(port->irq, port); |
| 450 | } |
| 451 | |
| 452 | static void asc_pm(struct uart_port *port, unsigned int state, |
| 453 | unsigned int oldstate) |
| 454 | { |
| 455 | struct asc_port *ascport = to_asc_port(port); |
| 456 | unsigned long flags = 0; |
| 457 | u32 ctl; |
| 458 | |
| 459 | switch (state) { |
| 460 | case UART_PM_STATE_ON: |
| 461 | clk_prepare_enable(ascport->clk); |
| 462 | break; |
| 463 | case UART_PM_STATE_OFF: |
| 464 | /* |
| 465 | * Disable the ASC baud rate generator, which is as close as |
| 466 | * we can come to turning it off. Note this is not called with |
| 467 | * the port spinlock held. |
| 468 | */ |
| 469 | spin_lock_irqsave(&port->lock, flags); |
| 470 | ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN; |
| 471 | asc_out(port, ASC_CTL, ctl); |
| 472 | spin_unlock_irqrestore(&port->lock, flags); |
| 473 | clk_disable_unprepare(ascport->clk); |
| 474 | break; |
| 475 | } |
| 476 | } |
| 477 | |
| 478 | static void asc_set_termios(struct uart_port *port, struct ktermios *termios, |
| 479 | struct ktermios *old) |
| 480 | { |
| 481 | struct asc_port *ascport = to_asc_port(port); |
| 482 | unsigned int baud; |
| 483 | u32 ctrl_val; |
| 484 | tcflag_t cflag; |
| 485 | unsigned long flags; |
| 486 | |
| 487 | /* Update termios to reflect hardware capabilities */ |
| 488 | termios->c_cflag &= ~(CMSPAR | |
| 489 | (ascport->hw_flow_control ? 0 : CRTSCTS)); |
| 490 | |
| 491 | port->uartclk = clk_get_rate(ascport->clk); |
| 492 | |
| 493 | baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); |
| 494 | cflag = termios->c_cflag; |
| 495 | |
| 496 | spin_lock_irqsave(&port->lock, flags); |
| 497 | |
| 498 | /* read control register */ |
| 499 | ctrl_val = asc_in(port, ASC_CTL); |
| 500 | |
| 501 | /* stop serial port and reset value */ |
| 502 | asc_out(port, ASC_CTL, (ctrl_val & ~ASC_CTL_RUN)); |
| 503 | ctrl_val = ASC_CTL_RXENABLE | ASC_CTL_FIFOENABLE; |
| 504 | |
| 505 | /* reset fifo rx & tx */ |
| 506 | asc_out(port, ASC_TXRESET, 1); |
| 507 | asc_out(port, ASC_RXRESET, 1); |
| 508 | |
| 509 | /* set character length */ |
| 510 | if ((cflag & CSIZE) == CS7) { |
| 511 | ctrl_val |= ASC_CTL_MODE_7BIT_PAR; |
| 512 | } else { |
| 513 | ctrl_val |= (cflag & PARENB) ? ASC_CTL_MODE_8BIT_PAR : |
| 514 | ASC_CTL_MODE_8BIT; |
| 515 | } |
| 516 | |
| 517 | /* set stop bit */ |
| 518 | ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT; |
| 519 | |
| 520 | /* odd parity */ |
| 521 | if (cflag & PARODD) |
| 522 | ctrl_val |= ASC_CTL_PARITYODD; |
| 523 | |
| 524 | /* hardware flow control */ |
| 525 | if ((cflag & CRTSCTS)) |
| 526 | ctrl_val |= ASC_CTL_CTSENABLE; |
| 527 | |
| 528 | if ((baud < 19200) && !ascport->force_m1) { |
| 529 | asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud))); |
| 530 | } else { |
| 531 | /* |
| 532 | * MODE 1: recommended for high bit rates (above 19.2K) |
| 533 | * |
| 534 | * baudrate * 16 * 2^16 |
| 535 | * ASCBaudRate = ------------------------ |
| 536 | * inputclock |
| 537 | * |
Maxime COQUELIN | 1d6ba28 | 2014-07-24 14:02:56 +0200 | [diff] [blame] | 538 | * To keep maths inside 64bits, we divide inputclock by 16. |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 539 | */ |
Maxime COQUELIN | 1d6ba28 | 2014-07-24 14:02:56 +0200 | [diff] [blame] | 540 | u64 dividend = (u64)baud * (1 << 16); |
| 541 | |
| 542 | do_div(dividend, port->uartclk / 16); |
| 543 | asc_out(port, ASC_BAUDRATE, dividend); |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 544 | ctrl_val |= ASC_CTL_BAUDMODE; |
| 545 | } |
| 546 | |
| 547 | uart_update_timeout(port, cflag, baud); |
| 548 | |
| 549 | ascport->port.read_status_mask = ASC_RXBUF_DUMMY_OE; |
| 550 | if (termios->c_iflag & INPCK) |
| 551 | ascport->port.read_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE; |
Peter Hurley | ef8b9dd | 2014-06-16 08:10:41 -0400 | [diff] [blame] | 552 | if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 553 | ascport->port.read_status_mask |= ASC_RXBUF_DUMMY_BE; |
| 554 | |
| 555 | /* |
| 556 | * Characters to ignore |
| 557 | */ |
| 558 | ascport->port.ignore_status_mask = 0; |
| 559 | if (termios->c_iflag & IGNPAR) |
| 560 | ascport->port.ignore_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE; |
| 561 | if (termios->c_iflag & IGNBRK) { |
| 562 | ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_BE; |
| 563 | /* |
| 564 | * If we're ignoring parity and break indicators, |
| 565 | * ignore overruns too (for real raw support). |
| 566 | */ |
| 567 | if (termios->c_iflag & IGNPAR) |
| 568 | ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_OE; |
| 569 | } |
| 570 | |
| 571 | /* |
| 572 | * Ignore all characters if CREAD is not set. |
| 573 | */ |
| 574 | if (!(termios->c_cflag & CREAD)) |
| 575 | ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_RX; |
| 576 | |
| 577 | /* Set the timeout */ |
| 578 | asc_out(port, ASC_TIMEOUT, 20); |
| 579 | |
| 580 | /* write final value and enable port */ |
| 581 | asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN)); |
| 582 | |
| 583 | spin_unlock_irqrestore(&port->lock, flags); |
| 584 | } |
| 585 | |
| 586 | static const char *asc_type(struct uart_port *port) |
| 587 | { |
| 588 | return (port->type == PORT_ASC) ? DRIVER_NAME : NULL; |
| 589 | } |
| 590 | |
| 591 | static void asc_release_port(struct uart_port *port) |
| 592 | { |
| 593 | } |
| 594 | |
| 595 | static int asc_request_port(struct uart_port *port) |
| 596 | { |
| 597 | return 0; |
| 598 | } |
| 599 | |
| 600 | /* |
| 601 | * Called when the port is opened, and UPF_BOOT_AUTOCONF flag is set |
| 602 | * Set type field if successful |
| 603 | */ |
| 604 | static void asc_config_port(struct uart_port *port, int flags) |
| 605 | { |
| 606 | if ((flags & UART_CONFIG_TYPE)) |
| 607 | port->type = PORT_ASC; |
| 608 | } |
| 609 | |
| 610 | static int |
| 611 | asc_verify_port(struct uart_port *port, struct serial_struct *ser) |
| 612 | { |
| 613 | /* No user changeable parameters */ |
| 614 | return -EINVAL; |
| 615 | } |
| 616 | |
| 617 | #ifdef CONFIG_CONSOLE_POLL |
| 618 | /* |
| 619 | * Console polling routines for writing and reading from the uart while |
| 620 | * in an interrupt or debug context (i.e. kgdb). |
| 621 | */ |
| 622 | |
| 623 | static int asc_get_poll_char(struct uart_port *port) |
| 624 | { |
| 625 | if (!(asc_in(port, ASC_STA) & ASC_STA_RBF)) |
| 626 | return NO_POLL_CHAR; |
| 627 | |
| 628 | return asc_in(port, ASC_RXBUF); |
| 629 | } |
| 630 | |
| 631 | static void asc_put_poll_char(struct uart_port *port, unsigned char c) |
| 632 | { |
Daniel Thompson | 1ffcd67 | 2014-05-13 17:08:57 +0100 | [diff] [blame] | 633 | while (!asc_txfifo_is_half_empty(port)) |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 634 | cpu_relax(); |
| 635 | asc_out(port, ASC_TXBUF, c); |
| 636 | } |
| 637 | |
| 638 | #endif /* CONFIG_CONSOLE_POLL */ |
| 639 | |
| 640 | /*---------------------------------------------------------------------*/ |
| 641 | |
Julia Lawall | eeb8bc1 | 2016-09-01 19:51:30 +0200 | [diff] [blame] | 642 | static const struct uart_ops asc_uart_ops = { |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 643 | .tx_empty = asc_tx_empty, |
| 644 | .set_mctrl = asc_set_mctrl, |
| 645 | .get_mctrl = asc_get_mctrl, |
| 646 | .start_tx = asc_start_tx, |
| 647 | .stop_tx = asc_stop_tx, |
| 648 | .stop_rx = asc_stop_rx, |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 649 | .break_ctl = asc_break_ctl, |
| 650 | .startup = asc_startup, |
| 651 | .shutdown = asc_shutdown, |
| 652 | .set_termios = asc_set_termios, |
| 653 | .type = asc_type, |
| 654 | .release_port = asc_release_port, |
| 655 | .request_port = asc_request_port, |
| 656 | .config_port = asc_config_port, |
| 657 | .verify_port = asc_verify_port, |
| 658 | .pm = asc_pm, |
| 659 | #ifdef CONFIG_CONSOLE_POLL |
| 660 | .poll_get_char = asc_get_poll_char, |
| 661 | .poll_put_char = asc_put_poll_char, |
| 662 | #endif /* CONFIG_CONSOLE_POLL */ |
| 663 | }; |
| 664 | |
| 665 | static int asc_init_port(struct asc_port *ascport, |
| 666 | struct platform_device *pdev) |
| 667 | { |
| 668 | struct uart_port *port = &ascport->port; |
Julia Lawall | 3abeff7 | 2013-08-19 13:20:36 +0200 | [diff] [blame] | 669 | struct resource *res; |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 670 | |
| 671 | port->iotype = UPIO_MEM; |
| 672 | port->flags = UPF_BOOT_AUTOCONF; |
| 673 | port->ops = &asc_uart_ops; |
| 674 | port->fifosize = ASC_FIFO_SIZE; |
| 675 | port->dev = &pdev->dev; |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 676 | port->irq = platform_get_irq(pdev, 0); |
| 677 | |
Julia Lawall | 3abeff7 | 2013-08-19 13:20:36 +0200 | [diff] [blame] | 678 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 679 | port->membase = devm_ioremap_resource(&pdev->dev, res); |
| 680 | if (IS_ERR(port->membase)) |
| 681 | return PTR_ERR(port->membase); |
| 682 | port->mapbase = res->start; |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 683 | |
| 684 | spin_lock_init(&port->lock); |
| 685 | |
| 686 | ascport->clk = devm_clk_get(&pdev->dev, NULL); |
| 687 | |
| 688 | if (WARN_ON(IS_ERR(ascport->clk))) |
| 689 | return -EINVAL; |
| 690 | /* ensure that clk rate is correct by enabling the clk */ |
| 691 | clk_prepare_enable(ascport->clk); |
| 692 | ascport->port.uartclk = clk_get_rate(ascport->clk); |
| 693 | WARN_ON(ascport->port.uartclk == 0); |
| 694 | clk_disable_unprepare(ascport->clk); |
| 695 | |
| 696 | return 0; |
| 697 | } |
| 698 | |
| 699 | static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev) |
| 700 | { |
| 701 | struct device_node *np = pdev->dev.of_node; |
| 702 | int id; |
| 703 | |
| 704 | if (!np) |
| 705 | return NULL; |
| 706 | |
| 707 | id = of_alias_get_id(np, ASC_SERIAL_NAME); |
| 708 | |
| 709 | if (id < 0) |
| 710 | id = 0; |
| 711 | |
| 712 | if (WARN_ON(id >= ASC_MAX_PORTS)) |
| 713 | return NULL; |
| 714 | |
| 715 | asc_ports[id].hw_flow_control = of_property_read_bool(np, |
| 716 | "st,hw-flow-control"); |
| 717 | asc_ports[id].force_m1 = of_property_read_bool(np, "st,force_m1"); |
| 718 | asc_ports[id].port.line = id; |
| 719 | return &asc_ports[id]; |
| 720 | } |
| 721 | |
Srinivas Kandagatla | a4f2dc9 | 2013-08-02 10:23:51 +0100 | [diff] [blame] | 722 | #ifdef CONFIG_OF |
Fabian Frederick | ed0bb23 | 2015-03-16 20:17:11 +0100 | [diff] [blame] | 723 | static const struct of_device_id asc_match[] = { |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 724 | { .compatible = "st,asc", }, |
| 725 | {}, |
| 726 | }; |
| 727 | |
| 728 | MODULE_DEVICE_TABLE(of, asc_match); |
Srinivas Kandagatla | a4f2dc9 | 2013-08-02 10:23:51 +0100 | [diff] [blame] | 729 | #endif |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 730 | |
| 731 | static int asc_serial_probe(struct platform_device *pdev) |
| 732 | { |
| 733 | int ret; |
| 734 | struct asc_port *ascport; |
| 735 | |
| 736 | ascport = asc_of_get_asc_port(pdev); |
| 737 | if (!ascport) |
| 738 | return -ENODEV; |
| 739 | |
| 740 | ret = asc_init_port(ascport, pdev); |
| 741 | if (ret) |
| 742 | return ret; |
| 743 | |
| 744 | ret = uart_add_one_port(&asc_uart_driver, &ascport->port); |
| 745 | if (ret) |
| 746 | return ret; |
| 747 | |
| 748 | platform_set_drvdata(pdev, &ascport->port); |
| 749 | |
| 750 | return 0; |
| 751 | } |
| 752 | |
| 753 | static int asc_serial_remove(struct platform_device *pdev) |
| 754 | { |
| 755 | struct uart_port *port = platform_get_drvdata(pdev); |
| 756 | |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 757 | return uart_remove_one_port(&asc_uart_driver, port); |
| 758 | } |
| 759 | |
| 760 | #ifdef CONFIG_PM_SLEEP |
| 761 | static int asc_serial_suspend(struct device *dev) |
| 762 | { |
| 763 | struct platform_device *pdev = to_platform_device(dev); |
| 764 | struct uart_port *port = platform_get_drvdata(pdev); |
| 765 | |
| 766 | return uart_suspend_port(&asc_uart_driver, port); |
| 767 | } |
| 768 | |
| 769 | static int asc_serial_resume(struct device *dev) |
| 770 | { |
| 771 | struct platform_device *pdev = to_platform_device(dev); |
| 772 | struct uart_port *port = platform_get_drvdata(pdev); |
| 773 | |
| 774 | return uart_resume_port(&asc_uart_driver, port); |
| 775 | } |
| 776 | |
| 777 | #endif /* CONFIG_PM_SLEEP */ |
| 778 | |
| 779 | /*----------------------------------------------------------------------*/ |
| 780 | |
| 781 | #ifdef CONFIG_SERIAL_ST_ASC_CONSOLE |
| 782 | static void asc_console_putchar(struct uart_port *port, int ch) |
| 783 | { |
| 784 | unsigned int timeout = 1000000; |
| 785 | |
| 786 | /* Wait for upto 1 second in case flow control is stopping us. */ |
Daniel Thompson | 1ffcd67 | 2014-05-13 17:08:57 +0100 | [diff] [blame] | 787 | while (--timeout && !asc_txfifo_is_half_empty(port)) |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 788 | udelay(1); |
| 789 | |
| 790 | asc_out(port, ASC_TXBUF, ch); |
| 791 | } |
| 792 | |
| 793 | /* |
| 794 | * Print a string to the serial port trying not to disturb |
| 795 | * any possible real use of the port... |
| 796 | */ |
| 797 | |
| 798 | static void asc_console_write(struct console *co, const char *s, unsigned count) |
| 799 | { |
| 800 | struct uart_port *port = &asc_ports[co->index].port; |
| 801 | unsigned long flags; |
| 802 | unsigned long timeout = 1000000; |
| 803 | int locked = 1; |
| 804 | u32 intenable; |
| 805 | |
| 806 | local_irq_save(flags); |
| 807 | if (port->sysrq) |
| 808 | locked = 0; /* asc_interrupt has already claimed the lock */ |
| 809 | else if (oops_in_progress) |
| 810 | locked = spin_trylock(&port->lock); |
| 811 | else |
| 812 | spin_lock(&port->lock); |
| 813 | |
| 814 | /* |
| 815 | * Disable interrupts so we don't get the IRQ line bouncing |
| 816 | * up and down while interrupts are disabled. |
| 817 | */ |
| 818 | intenable = asc_in(port, ASC_INTEN); |
| 819 | asc_out(port, ASC_INTEN, 0); |
| 820 | (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */ |
| 821 | |
| 822 | uart_console_write(port, s, count, asc_console_putchar); |
| 823 | |
| 824 | while (--timeout && !asc_txfifo_is_empty(port)) |
| 825 | udelay(1); |
| 826 | |
| 827 | asc_out(port, ASC_INTEN, intenable); |
| 828 | |
| 829 | if (locked) |
| 830 | spin_unlock(&port->lock); |
| 831 | local_irq_restore(flags); |
| 832 | } |
| 833 | |
| 834 | static int asc_console_setup(struct console *co, char *options) |
| 835 | { |
| 836 | struct asc_port *ascport; |
| 837 | int baud = 9600; |
| 838 | int bits = 8; |
| 839 | int parity = 'n'; |
| 840 | int flow = 'n'; |
| 841 | |
| 842 | if (co->index >= ASC_MAX_PORTS) |
| 843 | return -ENODEV; |
| 844 | |
| 845 | ascport = &asc_ports[co->index]; |
| 846 | |
| 847 | /* |
| 848 | * This driver does not support early console initialization |
| 849 | * (use ARM early printk support instead), so we only expect |
| 850 | * this to be called during the uart port registration when the |
| 851 | * driver gets probed and the port should be mapped at that point. |
| 852 | */ |
Maxime COQUELIN | 5b4e79a | 2014-07-24 14:02:55 +0200 | [diff] [blame] | 853 | if (ascport->port.mapbase == 0 || ascport->port.membase == NULL) |
| 854 | return -ENXIO; |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 855 | |
| 856 | if (options) |
| 857 | uart_parse_options(options, &baud, &parity, &bits, &flow); |
| 858 | |
| 859 | return uart_set_options(&ascport->port, co, baud, parity, bits, flow); |
| 860 | } |
| 861 | |
| 862 | static struct console asc_console = { |
| 863 | .name = ASC_SERIAL_NAME, |
| 864 | .device = uart_console_device, |
| 865 | .write = asc_console_write, |
| 866 | .setup = asc_console_setup, |
| 867 | .flags = CON_PRINTBUFFER, |
| 868 | .index = -1, |
| 869 | .data = &asc_uart_driver, |
| 870 | }; |
| 871 | |
| 872 | #define ASC_SERIAL_CONSOLE (&asc_console) |
| 873 | |
| 874 | #else |
| 875 | #define ASC_SERIAL_CONSOLE NULL |
| 876 | #endif /* CONFIG_SERIAL_ST_ASC_CONSOLE */ |
| 877 | |
| 878 | static struct uart_driver asc_uart_driver = { |
| 879 | .owner = THIS_MODULE, |
| 880 | .driver_name = DRIVER_NAME, |
| 881 | .dev_name = ASC_SERIAL_NAME, |
| 882 | .major = 0, |
| 883 | .minor = 0, |
| 884 | .nr = ASC_MAX_PORTS, |
| 885 | .cons = ASC_SERIAL_CONSOLE, |
| 886 | }; |
| 887 | |
| 888 | static const struct dev_pm_ops asc_serial_pm_ops = { |
| 889 | SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume) |
| 890 | }; |
| 891 | |
| 892 | static struct platform_driver asc_serial_driver = { |
| 893 | .probe = asc_serial_probe, |
| 894 | .remove = asc_serial_remove, |
| 895 | .driver = { |
| 896 | .name = DRIVER_NAME, |
| 897 | .pm = &asc_serial_pm_ops, |
Srinivas Kandagatla | c4b0585 | 2013-07-15 12:39:23 +0100 | [diff] [blame] | 898 | .of_match_table = of_match_ptr(asc_match), |
| 899 | }, |
| 900 | }; |
| 901 | |
| 902 | static int __init asc_init(void) |
| 903 | { |
| 904 | int ret; |
| 905 | static char banner[] __initdata = |
| 906 | KERN_INFO "STMicroelectronics ASC driver initialized\n"; |
| 907 | |
| 908 | printk(banner); |
| 909 | |
| 910 | ret = uart_register_driver(&asc_uart_driver); |
| 911 | if (ret) |
| 912 | return ret; |
| 913 | |
| 914 | ret = platform_driver_register(&asc_serial_driver); |
| 915 | if (ret) |
| 916 | uart_unregister_driver(&asc_uart_driver); |
| 917 | |
| 918 | return ret; |
| 919 | } |
| 920 | |
| 921 | static void __exit asc_exit(void) |
| 922 | { |
| 923 | platform_driver_unregister(&asc_serial_driver); |
| 924 | uart_unregister_driver(&asc_uart_driver); |
| 925 | } |
| 926 | |
| 927 | module_init(asc_init); |
| 928 | module_exit(asc_exit); |
| 929 | |
| 930 | MODULE_ALIAS("platform:" DRIVER_NAME); |
| 931 | MODULE_AUTHOR("STMicroelectronics (R&D) Limited"); |
| 932 | MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver"); |
| 933 | MODULE_LICENSE("GPL"); |