Tobias Klauser | 5bcd601 | 2010-05-05 10:35:22 +0200 | [diff] [blame] | 1 | /* |
| 2 | * altera_jtaguart.c -- Altera JTAG UART driver |
| 3 | * |
| 4 | * Based on mcf.c -- Freescale ColdFire UART driver |
| 5 | * |
| 6 | * (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com> |
| 7 | * (C) Copyright 2008, Thomas Chou <thomas@wytron.com.tw> |
| 8 | * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch> |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License as published by |
| 12 | * the Free Software Foundation; either version 2 of the License, or |
| 13 | * (at your option) any later version. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/interrupt.h> |
| 19 | #include <linux/module.h> |
| 20 | #include <linux/console.h> |
| 21 | #include <linux/tty.h> |
| 22 | #include <linux/tty_flip.h> |
| 23 | #include <linux/serial.h> |
| 24 | #include <linux/serial_core.h> |
| 25 | #include <linux/platform_device.h> |
| 26 | #include <linux/io.h> |
| 27 | #include <linux/altera_jtaguart.h> |
| 28 | |
| 29 | #define DRV_NAME "altera_jtaguart" |
| 30 | |
| 31 | /* |
| 32 | * Altera JTAG UART register definitions according to the Altera JTAG UART |
| 33 | * datasheet: http://www.altera.com/literature/hb/nios2/n2cpu_nii51009.pdf |
| 34 | */ |
| 35 | |
| 36 | #define ALTERA_JTAGUART_SIZE 8 |
| 37 | |
| 38 | #define ALTERA_JTAGUART_DATA_REG 0 |
| 39 | |
| 40 | #define ALTERA_JTAGUART_DATA_DATA_MSK 0x000000FF |
| 41 | #define ALTERA_JTAGUART_DATA_RVALID_MSK 0x00008000 |
| 42 | #define ALTERA_JTAGUART_DATA_RAVAIL_MSK 0xFFFF0000 |
| 43 | #define ALTERA_JTAGUART_DATA_RAVAIL_OFF 16 |
| 44 | |
| 45 | #define ALTERA_JTAGUART_CONTROL_REG 4 |
| 46 | |
| 47 | #define ALTERA_JTAGUART_CONTROL_RE_MSK 0x00000001 |
| 48 | #define ALTERA_JTAGUART_CONTROL_WE_MSK 0x00000002 |
| 49 | #define ALTERA_JTAGUART_CONTROL_RI_MSK 0x00000100 |
| 50 | #define ALTERA_JTAGUART_CONTROL_RI_OFF 8 |
| 51 | #define ALTERA_JTAGUART_CONTROL_WI_MSK 0x00000200 |
| 52 | #define ALTERA_JTAGUART_CONTROL_AC_MSK 0x00000400 |
| 53 | #define ALTERA_JTAGUART_CONTROL_WSPACE_MSK 0xFFFF0000 |
| 54 | #define ALTERA_JTAGUART_CONTROL_WSPACE_OFF 16 |
| 55 | |
| 56 | /* |
| 57 | * Local per-uart structure. |
| 58 | */ |
| 59 | struct altera_jtaguart { |
| 60 | struct uart_port port; |
| 61 | unsigned int sigs; /* Local copy of line sigs */ |
| 62 | unsigned long imr; /* Local IMR mirror */ |
| 63 | }; |
| 64 | |
| 65 | static unsigned int altera_jtaguart_tx_empty(struct uart_port *port) |
| 66 | { |
| 67 | return (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) & |
| 68 | ALTERA_JTAGUART_CONTROL_WSPACE_MSK) ? TIOCSER_TEMT : 0; |
| 69 | } |
| 70 | |
| 71 | static unsigned int altera_jtaguart_get_mctrl(struct uart_port *port) |
| 72 | { |
| 73 | return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; |
| 74 | } |
| 75 | |
| 76 | static void altera_jtaguart_set_mctrl(struct uart_port *port, unsigned int sigs) |
| 77 | { |
| 78 | } |
| 79 | |
| 80 | static void altera_jtaguart_start_tx(struct uart_port *port) |
| 81 | { |
| 82 | struct altera_jtaguart *pp = |
| 83 | container_of(port, struct altera_jtaguart, port); |
| 84 | |
| 85 | pp->imr |= ALTERA_JTAGUART_CONTROL_WE_MSK; |
| 86 | writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG); |
| 87 | } |
| 88 | |
| 89 | static void altera_jtaguart_stop_tx(struct uart_port *port) |
| 90 | { |
| 91 | struct altera_jtaguart *pp = |
| 92 | container_of(port, struct altera_jtaguart, port); |
| 93 | |
| 94 | pp->imr &= ~ALTERA_JTAGUART_CONTROL_WE_MSK; |
| 95 | writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG); |
| 96 | } |
| 97 | |
| 98 | static void altera_jtaguart_stop_rx(struct uart_port *port) |
| 99 | { |
| 100 | struct altera_jtaguart *pp = |
| 101 | container_of(port, struct altera_jtaguart, port); |
| 102 | |
| 103 | pp->imr &= ~ALTERA_JTAGUART_CONTROL_RE_MSK; |
| 104 | writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG); |
| 105 | } |
| 106 | |
| 107 | static void altera_jtaguart_break_ctl(struct uart_port *port, int break_state) |
| 108 | { |
| 109 | } |
| 110 | |
| 111 | static void altera_jtaguart_enable_ms(struct uart_port *port) |
| 112 | { |
| 113 | } |
| 114 | |
| 115 | static void altera_jtaguart_set_termios(struct uart_port *port, |
| 116 | struct ktermios *termios, |
| 117 | struct ktermios *old) |
| 118 | { |
| 119 | /* Just copy the old termios settings back */ |
| 120 | if (old) |
| 121 | tty_termios_copy_hw(termios, old); |
| 122 | } |
| 123 | |
| 124 | static void altera_jtaguart_rx_chars(struct altera_jtaguart *pp) |
| 125 | { |
| 126 | struct uart_port *port = &pp->port; |
| 127 | unsigned char ch, flag; |
| 128 | unsigned long status; |
| 129 | |
| 130 | while ((status = readl(port->membase + ALTERA_JTAGUART_DATA_REG)) & |
| 131 | ALTERA_JTAGUART_DATA_RVALID_MSK) { |
| 132 | ch = status & ALTERA_JTAGUART_DATA_DATA_MSK; |
| 133 | flag = TTY_NORMAL; |
| 134 | port->icount.rx++; |
| 135 | |
| 136 | if (uart_handle_sysrq_char(port, ch)) |
| 137 | continue; |
| 138 | uart_insert_char(port, 0, 0, ch, flag); |
| 139 | } |
| 140 | |
| 141 | tty_flip_buffer_push(port->state->port.tty); |
| 142 | } |
| 143 | |
| 144 | static void altera_jtaguart_tx_chars(struct altera_jtaguart *pp) |
| 145 | { |
| 146 | struct uart_port *port = &pp->port; |
| 147 | struct circ_buf *xmit = &port->state->xmit; |
| 148 | unsigned int pending, count; |
| 149 | |
| 150 | if (port->x_char) { |
| 151 | /* Send special char - probably flow control */ |
| 152 | writel(port->x_char, port->membase + ALTERA_JTAGUART_DATA_REG); |
| 153 | port->x_char = 0; |
| 154 | port->icount.tx++; |
| 155 | return; |
| 156 | } |
| 157 | |
| 158 | pending = uart_circ_chars_pending(xmit); |
| 159 | if (pending > 0) { |
| 160 | count = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) & |
| 161 | ALTERA_JTAGUART_CONTROL_WSPACE_MSK) >> |
| 162 | ALTERA_JTAGUART_CONTROL_WSPACE_OFF; |
| 163 | if (count > pending) |
| 164 | count = pending; |
| 165 | if (count > 0) { |
| 166 | pending -= count; |
| 167 | while (count--) { |
| 168 | writel(xmit->buf[xmit->tail], |
| 169 | port->membase + ALTERA_JTAGUART_DATA_REG); |
| 170 | xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); |
| 171 | port->icount.tx++; |
| 172 | } |
| 173 | if (pending < WAKEUP_CHARS) |
| 174 | uart_write_wakeup(port); |
| 175 | } |
| 176 | } |
| 177 | |
| 178 | if (pending == 0) { |
| 179 | pp->imr &= ~ALTERA_JTAGUART_CONTROL_WE_MSK; |
| 180 | writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG); |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | static irqreturn_t altera_jtaguart_interrupt(int irq, void *data) |
| 185 | { |
| 186 | struct uart_port *port = data; |
| 187 | struct altera_jtaguart *pp = |
| 188 | container_of(port, struct altera_jtaguart, port); |
| 189 | unsigned int isr; |
| 190 | |
| 191 | isr = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) >> |
| 192 | ALTERA_JTAGUART_CONTROL_RI_OFF) & pp->imr; |
| 193 | |
| 194 | spin_lock(&port->lock); |
| 195 | |
| 196 | if (isr & ALTERA_JTAGUART_CONTROL_RE_MSK) |
| 197 | altera_jtaguart_rx_chars(pp); |
| 198 | if (isr & ALTERA_JTAGUART_CONTROL_WE_MSK) |
| 199 | altera_jtaguart_tx_chars(pp); |
| 200 | |
| 201 | spin_unlock(&port->lock); |
| 202 | |
| 203 | return IRQ_RETVAL(isr); |
| 204 | } |
| 205 | |
| 206 | static void altera_jtaguart_config_port(struct uart_port *port, int flags) |
| 207 | { |
| 208 | port->type = PORT_ALTERA_JTAGUART; |
| 209 | |
| 210 | /* Clear mask, so no surprise interrupts. */ |
| 211 | writel(0, port->membase + ALTERA_JTAGUART_CONTROL_REG); |
| 212 | } |
| 213 | |
| 214 | static int altera_jtaguart_startup(struct uart_port *port) |
| 215 | { |
| 216 | struct altera_jtaguart *pp = |
| 217 | container_of(port, struct altera_jtaguart, port); |
| 218 | unsigned long flags; |
| 219 | int ret; |
| 220 | |
| 221 | ret = request_irq(port->irq, altera_jtaguart_interrupt, IRQF_DISABLED, |
| 222 | DRV_NAME, port); |
| 223 | if (ret) { |
| 224 | pr_err(DRV_NAME ": unable to attach Altera JTAG UART %d " |
| 225 | "interrupt vector=%d\n", port->line, port->irq); |
| 226 | return ret; |
| 227 | } |
| 228 | |
| 229 | spin_lock_irqsave(&port->lock, flags); |
| 230 | |
| 231 | /* Enable RX interrupts now */ |
| 232 | pp->imr = ALTERA_JTAGUART_CONTROL_RE_MSK; |
| 233 | writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG); |
| 234 | |
| 235 | spin_unlock_irqrestore(&port->lock, flags); |
| 236 | |
| 237 | return 0; |
| 238 | } |
| 239 | |
| 240 | static void altera_jtaguart_shutdown(struct uart_port *port) |
| 241 | { |
| 242 | struct altera_jtaguart *pp = |
| 243 | container_of(port, struct altera_jtaguart, port); |
| 244 | unsigned long flags; |
| 245 | |
| 246 | spin_lock_irqsave(&port->lock, flags); |
| 247 | |
| 248 | /* Disable all interrupts now */ |
| 249 | pp->imr = 0; |
| 250 | writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG); |
| 251 | |
| 252 | spin_unlock_irqrestore(&port->lock, flags); |
| 253 | |
| 254 | free_irq(port->irq, port); |
| 255 | } |
| 256 | |
| 257 | static const char *altera_jtaguart_type(struct uart_port *port) |
| 258 | { |
| 259 | return (port->type == PORT_ALTERA_JTAGUART) ? "Altera JTAG UART" : NULL; |
| 260 | } |
| 261 | |
| 262 | static int altera_jtaguart_request_port(struct uart_port *port) |
| 263 | { |
| 264 | /* UARTs always present */ |
| 265 | return 0; |
| 266 | } |
| 267 | |
| 268 | static void altera_jtaguart_release_port(struct uart_port *port) |
| 269 | { |
| 270 | /* Nothing to release... */ |
| 271 | } |
| 272 | |
| 273 | static int altera_jtaguart_verify_port(struct uart_port *port, |
| 274 | struct serial_struct *ser) |
| 275 | { |
| 276 | if (ser->type != PORT_UNKNOWN && ser->type != PORT_ALTERA_JTAGUART) |
| 277 | return -EINVAL; |
| 278 | return 0; |
| 279 | } |
| 280 | |
| 281 | /* |
| 282 | * Define the basic serial functions we support. |
| 283 | */ |
| 284 | static struct uart_ops altera_jtaguart_ops = { |
| 285 | .tx_empty = altera_jtaguart_tx_empty, |
| 286 | .get_mctrl = altera_jtaguart_get_mctrl, |
| 287 | .set_mctrl = altera_jtaguart_set_mctrl, |
| 288 | .start_tx = altera_jtaguart_start_tx, |
| 289 | .stop_tx = altera_jtaguart_stop_tx, |
| 290 | .stop_rx = altera_jtaguart_stop_rx, |
| 291 | .enable_ms = altera_jtaguart_enable_ms, |
| 292 | .break_ctl = altera_jtaguart_break_ctl, |
| 293 | .startup = altera_jtaguart_startup, |
| 294 | .shutdown = altera_jtaguart_shutdown, |
| 295 | .set_termios = altera_jtaguart_set_termios, |
| 296 | .type = altera_jtaguart_type, |
| 297 | .request_port = altera_jtaguart_request_port, |
| 298 | .release_port = altera_jtaguart_release_port, |
| 299 | .config_port = altera_jtaguart_config_port, |
| 300 | .verify_port = altera_jtaguart_verify_port, |
| 301 | }; |
| 302 | |
| 303 | #define ALTERA_JTAGUART_MAXPORTS 1 |
| 304 | static struct altera_jtaguart altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS]; |
| 305 | |
| 306 | #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE) |
| 307 | |
| 308 | int __init early_altera_jtaguart_setup(struct altera_jtaguart_platform_uart |
| 309 | *platp) |
| 310 | { |
| 311 | struct uart_port *port; |
| 312 | int i; |
| 313 | |
| 314 | for (i = 0; i < ALTERA_JTAGUART_MAXPORTS && platp[i].mapbase; i++) { |
| 315 | port = &altera_jtaguart_ports[i].port; |
| 316 | |
| 317 | port->line = i; |
| 318 | port->type = PORT_ALTERA_JTAGUART; |
| 319 | port->mapbase = platp[i].mapbase; |
| 320 | port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE); |
| 321 | port->iotype = SERIAL_IO_MEM; |
| 322 | port->irq = platp[i].irq; |
| 323 | port->flags = ASYNC_BOOT_AUTOCONF; |
| 324 | port->ops = &altera_jtaguart_ops; |
| 325 | } |
| 326 | |
| 327 | return 0; |
| 328 | } |
| 329 | |
| 330 | #if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS) |
| 331 | static void altera_jtaguart_console_putc(struct console *co, const char c) |
| 332 | { |
| 333 | struct uart_port *port = &(altera_jtaguart_ports + co->index)->port; |
| 334 | unsigned long status; |
| 335 | unsigned long flags; |
| 336 | |
| 337 | spin_lock_irqsave(&port->lock, flags); |
| 338 | while (((status = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG)) & |
| 339 | ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) { |
| 340 | if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) { |
| 341 | spin_unlock_irqrestore(&port->lock, flags); |
| 342 | return; /* no connection activity */ |
| 343 | } |
| 344 | spin_unlock_irqrestore(&port->lock, flags); |
| 345 | cpu_relax(); |
| 346 | spin_lock_irqsave(&port->lock, flags); |
| 347 | } |
| 348 | writel(c, port->membase + ALTERA_JTAGUART_DATA_REG); |
| 349 | spin_unlock_irqrestore(&port->lock, flags); |
| 350 | } |
| 351 | #else |
| 352 | static void altera_jtaguart_console_putc(struct console *co, const char c) |
| 353 | { |
| 354 | struct uart_port *port = &(altera_jtaguart_ports + co->index)->port; |
| 355 | unsigned long flags; |
| 356 | |
| 357 | spin_lock_irqsave(&port->lock, flags); |
| 358 | while ((readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) & |
| 359 | ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) { |
| 360 | spin_unlock_irqrestore(&port->lock, flags); |
| 361 | cpu_relax(); |
| 362 | spin_lock_irqsave(&port->lock, flags); |
| 363 | } |
| 364 | writel(c, port->membase + ALTERA_JTAGUART_DATA_REG); |
| 365 | spin_unlock_irqrestore(&port->lock, flags); |
| 366 | } |
| 367 | #endif |
| 368 | |
| 369 | static void altera_jtaguart_console_write(struct console *co, const char *s, |
| 370 | unsigned int count) |
| 371 | { |
| 372 | for (; count; count--, s++) { |
| 373 | altera_jtaguart_console_putc(co, *s); |
| 374 | if (*s == '\n') |
| 375 | altera_jtaguart_console_putc(co, '\r'); |
| 376 | } |
| 377 | } |
| 378 | |
| 379 | static int __init altera_jtaguart_console_setup(struct console *co, |
| 380 | char *options) |
| 381 | { |
| 382 | struct uart_port *port; |
| 383 | |
| 384 | if (co->index < 0 || co->index >= ALTERA_JTAGUART_MAXPORTS) |
| 385 | return -EINVAL; |
| 386 | port = &altera_jtaguart_ports[co->index].port; |
| 387 | if (port->membase == 0) |
| 388 | return -ENODEV; |
| 389 | return 0; |
| 390 | } |
| 391 | |
| 392 | static struct uart_driver altera_jtaguart_driver; |
| 393 | |
| 394 | static struct console altera_jtaguart_console = { |
| 395 | .name = "ttyJ", |
| 396 | .write = altera_jtaguart_console_write, |
| 397 | .device = uart_console_device, |
| 398 | .setup = altera_jtaguart_console_setup, |
| 399 | .flags = CON_PRINTBUFFER, |
| 400 | .index = -1, |
| 401 | .data = &altera_jtaguart_driver, |
| 402 | }; |
| 403 | |
| 404 | static int __init altera_jtaguart_console_init(void) |
| 405 | { |
| 406 | register_console(&altera_jtaguart_console); |
| 407 | return 0; |
| 408 | } |
| 409 | |
| 410 | console_initcall(altera_jtaguart_console_init); |
| 411 | |
| 412 | #define ALTERA_JTAGUART_CONSOLE (&altera_jtaguart_console) |
| 413 | |
| 414 | #else |
| 415 | |
| 416 | #define ALTERA_JTAGUART_CONSOLE NULL |
| 417 | |
| 418 | #endif /* CONFIG_ALTERA_JTAGUART_CONSOLE */ |
| 419 | |
| 420 | static struct uart_driver altera_jtaguart_driver = { |
| 421 | .owner = THIS_MODULE, |
| 422 | .driver_name = "altera_jtaguart", |
| 423 | .dev_name = "ttyJ", |
| 424 | .major = ALTERA_JTAGUART_MAJOR, |
| 425 | .minor = ALTERA_JTAGUART_MINOR, |
| 426 | .nr = ALTERA_JTAGUART_MAXPORTS, |
| 427 | .cons = ALTERA_JTAGUART_CONSOLE, |
| 428 | }; |
| 429 | |
| 430 | static int __devinit altera_jtaguart_probe(struct platform_device *pdev) |
| 431 | { |
| 432 | struct altera_jtaguart_platform_uart *platp = pdev->dev.platform_data; |
| 433 | struct uart_port *port; |
| 434 | int i; |
| 435 | |
| 436 | for (i = 0; i < ALTERA_JTAGUART_MAXPORTS && platp[i].mapbase; i++) { |
| 437 | port = &altera_jtaguart_ports[i].port; |
| 438 | |
| 439 | port->line = i; |
| 440 | port->type = PORT_ALTERA_JTAGUART; |
| 441 | port->mapbase = platp[i].mapbase; |
| 442 | port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE); |
| 443 | port->iotype = SERIAL_IO_MEM; |
| 444 | port->irq = platp[i].irq; |
| 445 | port->ops = &altera_jtaguart_ops; |
| 446 | port->flags = ASYNC_BOOT_AUTOCONF; |
| 447 | |
| 448 | uart_add_one_port(&altera_jtaguart_driver, port); |
| 449 | } |
| 450 | |
| 451 | return 0; |
| 452 | } |
| 453 | |
| 454 | static int __devexit altera_jtaguart_remove(struct platform_device *pdev) |
| 455 | { |
| 456 | struct uart_port *port; |
| 457 | int i; |
| 458 | |
| 459 | for (i = 0; i < ALTERA_JTAGUART_MAXPORTS; i++) { |
| 460 | port = &altera_jtaguart_ports[i].port; |
| 461 | if (port) |
| 462 | uart_remove_one_port(&altera_jtaguart_driver, port); |
| 463 | } |
| 464 | |
| 465 | return 0; |
| 466 | } |
| 467 | |
| 468 | static struct platform_driver altera_jtaguart_platform_driver = { |
| 469 | .probe = altera_jtaguart_probe, |
| 470 | .remove = __devexit_p(altera_jtaguart_remove), |
| 471 | .driver = { |
| 472 | .name = DRV_NAME, |
| 473 | .owner = THIS_MODULE, |
| 474 | }, |
| 475 | }; |
| 476 | |
| 477 | static int __init altera_jtaguart_init(void) |
| 478 | { |
| 479 | int rc; |
| 480 | |
| 481 | rc = uart_register_driver(&altera_jtaguart_driver); |
| 482 | if (rc) |
| 483 | return rc; |
| 484 | rc = platform_driver_register(&altera_jtaguart_platform_driver); |
| 485 | if (rc) { |
| 486 | uart_unregister_driver(&altera_jtaguart_driver); |
| 487 | return rc; |
| 488 | } |
| 489 | return 0; |
| 490 | } |
| 491 | |
| 492 | static void __exit altera_jtaguart_exit(void) |
| 493 | { |
| 494 | platform_driver_unregister(&altera_jtaguart_platform_driver); |
| 495 | uart_unregister_driver(&altera_jtaguart_driver); |
| 496 | } |
| 497 | |
| 498 | module_init(altera_jtaguart_init); |
| 499 | module_exit(altera_jtaguart_exit); |
| 500 | |
| 501 | MODULE_DESCRIPTION("Altera JTAG UART driver"); |
| 502 | MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); |
| 503 | MODULE_LICENSE("GPL"); |
| 504 | MODULE_ALIAS("platform:" DRV_NAME); |