Linux 4.19.133
[linux/fpc-iii.git] / drivers / tty / serial / ar933x_uart.c
blobea12f10610b64dd46062735fc4e682213c407167
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Atheros AR933X SoC built-in UART driver
5 * Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
7 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
8 */
10 #include <linux/module.h>
11 #include <linux/ioport.h>
12 #include <linux/init.h>
13 #include <linux/console.h>
14 #include <linux/sysrq.h>
15 #include <linux/delay.h>
16 #include <linux/platform_device.h>
17 #include <linux/of.h>
18 #include <linux/of_platform.h>
19 #include <linux/tty.h>
20 #include <linux/tty_flip.h>
21 #include <linux/serial_core.h>
22 #include <linux/serial.h>
23 #include <linux/slab.h>
24 #include <linux/io.h>
25 #include <linux/irq.h>
26 #include <linux/clk.h>
28 #include <asm/div64.h>
30 #include <asm/mach-ath79/ar933x_uart.h>
32 #define DRIVER_NAME "ar933x-uart"
34 #define AR933X_UART_MAX_SCALE 0xff
35 #define AR933X_UART_MAX_STEP 0xffff
37 #define AR933X_UART_MIN_BAUD 300
38 #define AR933X_UART_MAX_BAUD 3000000
40 #define AR933X_DUMMY_STATUS_RD 0x01
42 static struct uart_driver ar933x_uart_driver;
44 struct ar933x_uart_port {
45 struct uart_port port;
46 unsigned int ier; /* shadow Interrupt Enable Register */
47 unsigned int min_baud;
48 unsigned int max_baud;
49 struct clk *clk;
52 static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
53 int offset)
55 return readl(up->port.membase + offset);
58 static inline void ar933x_uart_write(struct ar933x_uart_port *up,
59 int offset, unsigned int value)
61 writel(value, up->port.membase + offset);
64 static inline void ar933x_uart_rmw(struct ar933x_uart_port *up,
65 unsigned int offset,
66 unsigned int mask,
67 unsigned int val)
69 unsigned int t;
71 t = ar933x_uart_read(up, offset);
72 t &= ~mask;
73 t |= val;
74 ar933x_uart_write(up, offset, t);
77 static inline void ar933x_uart_rmw_set(struct ar933x_uart_port *up,
78 unsigned int offset,
79 unsigned int val)
81 ar933x_uart_rmw(up, offset, 0, val);
84 static inline void ar933x_uart_rmw_clear(struct ar933x_uart_port *up,
85 unsigned int offset,
86 unsigned int val)
88 ar933x_uart_rmw(up, offset, val, 0);
91 static inline void ar933x_uart_start_tx_interrupt(struct ar933x_uart_port *up)
93 up->ier |= AR933X_UART_INT_TX_EMPTY;
94 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
97 static inline void ar933x_uart_stop_tx_interrupt(struct ar933x_uart_port *up)
99 up->ier &= ~AR933X_UART_INT_TX_EMPTY;
100 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
103 static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch)
105 unsigned int rdata;
107 rdata = ch & AR933X_UART_DATA_TX_RX_MASK;
108 rdata |= AR933X_UART_DATA_TX_CSR;
109 ar933x_uart_write(up, AR933X_UART_DATA_REG, rdata);
112 static unsigned int ar933x_uart_tx_empty(struct uart_port *port)
114 struct ar933x_uart_port *up =
115 container_of(port, struct ar933x_uart_port, port);
116 unsigned long flags;
117 unsigned int rdata;
119 spin_lock_irqsave(&up->port.lock, flags);
120 rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
121 spin_unlock_irqrestore(&up->port.lock, flags);
123 return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT;
126 static unsigned int ar933x_uart_get_mctrl(struct uart_port *port)
128 return TIOCM_CAR;
131 static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
135 static void ar933x_uart_start_tx(struct uart_port *port)
137 struct ar933x_uart_port *up =
138 container_of(port, struct ar933x_uart_port, port);
140 ar933x_uart_start_tx_interrupt(up);
143 static void ar933x_uart_stop_tx(struct uart_port *port)
145 struct ar933x_uart_port *up =
146 container_of(port, struct ar933x_uart_port, port);
148 ar933x_uart_stop_tx_interrupt(up);
151 static void ar933x_uart_stop_rx(struct uart_port *port)
153 struct ar933x_uart_port *up =
154 container_of(port, struct ar933x_uart_port, port);
156 up->ier &= ~AR933X_UART_INT_RX_VALID;
157 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
160 static void ar933x_uart_break_ctl(struct uart_port *port, int break_state)
162 struct ar933x_uart_port *up =
163 container_of(port, struct ar933x_uart_port, port);
164 unsigned long flags;
166 spin_lock_irqsave(&up->port.lock, flags);
167 if (break_state == -1)
168 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
169 AR933X_UART_CS_TX_BREAK);
170 else
171 ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
172 AR933X_UART_CS_TX_BREAK);
173 spin_unlock_irqrestore(&up->port.lock, flags);
177 * baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
179 static unsigned long ar933x_uart_get_baud(unsigned int clk,
180 unsigned int scale,
181 unsigned int step)
183 u64 t;
184 u32 div;
186 div = (2 << 16) * (scale + 1);
187 t = clk;
188 t *= step;
189 t += (div / 2);
190 do_div(t, div);
192 return t;
195 static void ar933x_uart_get_scale_step(unsigned int clk,
196 unsigned int baud,
197 unsigned int *scale,
198 unsigned int *step)
200 unsigned int tscale;
201 long min_diff;
203 *scale = 0;
204 *step = 0;
206 min_diff = baud;
207 for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) {
208 u64 tstep;
209 int diff;
211 tstep = baud * (tscale + 1);
212 tstep *= (2 << 16);
213 do_div(tstep, clk);
215 if (tstep > AR933X_UART_MAX_STEP)
216 break;
218 diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud);
219 if (diff < min_diff) {
220 min_diff = diff;
221 *scale = tscale;
222 *step = tstep;
227 static void ar933x_uart_set_termios(struct uart_port *port,
228 struct ktermios *new,
229 struct ktermios *old)
231 struct ar933x_uart_port *up =
232 container_of(port, struct ar933x_uart_port, port);
233 unsigned int cs;
234 unsigned long flags;
235 unsigned int baud, scale, step;
237 /* Only CS8 is supported */
238 new->c_cflag &= ~CSIZE;
239 new->c_cflag |= CS8;
241 /* Only one stop bit is supported */
242 new->c_cflag &= ~CSTOPB;
244 cs = 0;
245 if (new->c_cflag & PARENB) {
246 if (!(new->c_cflag & PARODD))
247 cs |= AR933X_UART_CS_PARITY_EVEN;
248 else
249 cs |= AR933X_UART_CS_PARITY_ODD;
250 } else {
251 cs |= AR933X_UART_CS_PARITY_NONE;
254 /* Mark/space parity is not supported */
255 new->c_cflag &= ~CMSPAR;
257 baud = uart_get_baud_rate(port, new, old, up->min_baud, up->max_baud);
258 ar933x_uart_get_scale_step(port->uartclk, baud, &scale, &step);
261 * Ok, we're now changing the port state. Do it with
262 * interrupts disabled.
264 spin_lock_irqsave(&up->port.lock, flags);
266 /* disable the UART */
267 ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
268 AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S);
270 /* Update the per-port timeout. */
271 uart_update_timeout(port, new->c_cflag, baud);
273 up->port.ignore_status_mask = 0;
275 /* ignore all characters if CREAD is not set */
276 if ((new->c_cflag & CREAD) == 0)
277 up->port.ignore_status_mask |= AR933X_DUMMY_STATUS_RD;
279 ar933x_uart_write(up, AR933X_UART_CLOCK_REG,
280 scale << AR933X_UART_CLOCK_SCALE_S | step);
282 /* setup configuration register */
283 ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs);
285 /* enable host interrupt */
286 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
287 AR933X_UART_CS_HOST_INT_EN);
289 /* enable RX and TX ready overide */
290 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
291 AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE);
293 /* reenable the UART */
294 ar933x_uart_rmw(up, AR933X_UART_CS_REG,
295 AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S,
296 AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S);
298 spin_unlock_irqrestore(&up->port.lock, flags);
300 if (tty_termios_baud_rate(new))
301 tty_termios_encode_baud_rate(new, baud, baud);
304 static void ar933x_uart_rx_chars(struct ar933x_uart_port *up)
306 struct tty_port *port = &up->port.state->port;
307 int max_count = 256;
309 do {
310 unsigned int rdata;
311 unsigned char ch;
313 rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
314 if ((rdata & AR933X_UART_DATA_RX_CSR) == 0)
315 break;
317 /* remove the character from the FIFO */
318 ar933x_uart_write(up, AR933X_UART_DATA_REG,
319 AR933X_UART_DATA_RX_CSR);
321 up->port.icount.rx++;
322 ch = rdata & AR933X_UART_DATA_TX_RX_MASK;
324 if (uart_handle_sysrq_char(&up->port, ch))
325 continue;
327 if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0)
328 tty_insert_flip_char(port, ch, TTY_NORMAL);
329 } while (max_count-- > 0);
331 spin_unlock(&up->port.lock);
332 tty_flip_buffer_push(port);
333 spin_lock(&up->port.lock);
336 static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
338 struct circ_buf *xmit = &up->port.state->xmit;
339 int count;
341 if (uart_tx_stopped(&up->port))
342 return;
344 count = up->port.fifosize;
345 do {
346 unsigned int rdata;
348 rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
349 if ((rdata & AR933X_UART_DATA_TX_CSR) == 0)
350 break;
352 if (up->port.x_char) {
353 ar933x_uart_putc(up, up->port.x_char);
354 up->port.icount.tx++;
355 up->port.x_char = 0;
356 continue;
359 if (uart_circ_empty(xmit))
360 break;
362 ar933x_uart_putc(up, xmit->buf[xmit->tail]);
364 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
365 up->port.icount.tx++;
366 } while (--count > 0);
368 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
369 uart_write_wakeup(&up->port);
371 if (!uart_circ_empty(xmit))
372 ar933x_uart_start_tx_interrupt(up);
375 static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id)
377 struct ar933x_uart_port *up = dev_id;
378 unsigned int status;
380 status = ar933x_uart_read(up, AR933X_UART_CS_REG);
381 if ((status & AR933X_UART_CS_HOST_INT) == 0)
382 return IRQ_NONE;
384 spin_lock(&up->port.lock);
386 status = ar933x_uart_read(up, AR933X_UART_INT_REG);
387 status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
389 if (status & AR933X_UART_INT_RX_VALID) {
390 ar933x_uart_write(up, AR933X_UART_INT_REG,
391 AR933X_UART_INT_RX_VALID);
392 ar933x_uart_rx_chars(up);
395 if (status & AR933X_UART_INT_TX_EMPTY) {
396 ar933x_uart_write(up, AR933X_UART_INT_REG,
397 AR933X_UART_INT_TX_EMPTY);
398 ar933x_uart_stop_tx_interrupt(up);
399 ar933x_uart_tx_chars(up);
402 spin_unlock(&up->port.lock);
404 return IRQ_HANDLED;
407 static int ar933x_uart_startup(struct uart_port *port)
409 struct ar933x_uart_port *up =
410 container_of(port, struct ar933x_uart_port, port);
411 unsigned long flags;
412 int ret;
414 ret = request_irq(up->port.irq, ar933x_uart_interrupt,
415 up->port.irqflags, dev_name(up->port.dev), up);
416 if (ret)
417 return ret;
419 spin_lock_irqsave(&up->port.lock, flags);
421 /* Enable HOST interrupts */
422 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
423 AR933X_UART_CS_HOST_INT_EN);
425 /* enable RX and TX ready overide */
426 ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
427 AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE);
429 /* Enable RX interrupts */
430 up->ier = AR933X_UART_INT_RX_VALID;
431 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
433 spin_unlock_irqrestore(&up->port.lock, flags);
435 return 0;
438 static void ar933x_uart_shutdown(struct uart_port *port)
440 struct ar933x_uart_port *up =
441 container_of(port, struct ar933x_uart_port, port);
443 /* Disable all interrupts */
444 up->ier = 0;
445 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
447 /* Disable break condition */
448 ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
449 AR933X_UART_CS_TX_BREAK);
451 free_irq(up->port.irq, up);
454 static const char *ar933x_uart_type(struct uart_port *port)
456 return (port->type == PORT_AR933X) ? "AR933X UART" : NULL;
459 static void ar933x_uart_release_port(struct uart_port *port)
461 /* Nothing to release ... */
464 static int ar933x_uart_request_port(struct uart_port *port)
466 /* UARTs always present */
467 return 0;
470 static void ar933x_uart_config_port(struct uart_port *port, int flags)
472 if (flags & UART_CONFIG_TYPE)
473 port->type = PORT_AR933X;
476 static int ar933x_uart_verify_port(struct uart_port *port,
477 struct serial_struct *ser)
479 struct ar933x_uart_port *up =
480 container_of(port, struct ar933x_uart_port, port);
482 if (ser->type != PORT_UNKNOWN &&
483 ser->type != PORT_AR933X)
484 return -EINVAL;
486 if (ser->irq < 0 || ser->irq >= NR_IRQS)
487 return -EINVAL;
489 if (ser->baud_base < up->min_baud ||
490 ser->baud_base > up->max_baud)
491 return -EINVAL;
493 return 0;
496 static const struct uart_ops ar933x_uart_ops = {
497 .tx_empty = ar933x_uart_tx_empty,
498 .set_mctrl = ar933x_uart_set_mctrl,
499 .get_mctrl = ar933x_uart_get_mctrl,
500 .stop_tx = ar933x_uart_stop_tx,
501 .start_tx = ar933x_uart_start_tx,
502 .stop_rx = ar933x_uart_stop_rx,
503 .break_ctl = ar933x_uart_break_ctl,
504 .startup = ar933x_uart_startup,
505 .shutdown = ar933x_uart_shutdown,
506 .set_termios = ar933x_uart_set_termios,
507 .type = ar933x_uart_type,
508 .release_port = ar933x_uart_release_port,
509 .request_port = ar933x_uart_request_port,
510 .config_port = ar933x_uart_config_port,
511 .verify_port = ar933x_uart_verify_port,
514 #ifdef CONFIG_SERIAL_AR933X_CONSOLE
515 static struct ar933x_uart_port *
516 ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS];
518 static void ar933x_uart_wait_xmitr(struct ar933x_uart_port *up)
520 unsigned int status;
521 unsigned int timeout = 60000;
523 /* Wait up to 60ms for the character(s) to be sent. */
524 do {
525 status = ar933x_uart_read(up, AR933X_UART_DATA_REG);
526 if (--timeout == 0)
527 break;
528 udelay(1);
529 } while ((status & AR933X_UART_DATA_TX_CSR) == 0);
532 static void ar933x_uart_console_putchar(struct uart_port *port, int ch)
534 struct ar933x_uart_port *up =
535 container_of(port, struct ar933x_uart_port, port);
537 ar933x_uart_wait_xmitr(up);
538 ar933x_uart_putc(up, ch);
541 static void ar933x_uart_console_write(struct console *co, const char *s,
542 unsigned int count)
544 struct ar933x_uart_port *up = ar933x_console_ports[co->index];
545 unsigned long flags;
546 unsigned int int_en;
547 int locked = 1;
549 local_irq_save(flags);
551 if (up->port.sysrq)
552 locked = 0;
553 else if (oops_in_progress)
554 locked = spin_trylock(&up->port.lock);
555 else
556 spin_lock(&up->port.lock);
559 * First save the IER then disable the interrupts
561 int_en = ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
562 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0);
564 uart_console_write(&up->port, s, count, ar933x_uart_console_putchar);
567 * Finally, wait for transmitter to become empty
568 * and restore the IER
570 ar933x_uart_wait_xmitr(up);
571 ar933x_uart_write(up, AR933X_UART_INT_EN_REG, int_en);
573 ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS);
575 if (locked)
576 spin_unlock(&up->port.lock);
578 local_irq_restore(flags);
581 static int ar933x_uart_console_setup(struct console *co, char *options)
583 struct ar933x_uart_port *up;
584 int baud = 115200;
585 int bits = 8;
586 int parity = 'n';
587 int flow = 'n';
589 if (co->index < 0 || co->index >= CONFIG_SERIAL_AR933X_NR_UARTS)
590 return -EINVAL;
592 up = ar933x_console_ports[co->index];
593 if (!up)
594 return -ENODEV;
596 if (options)
597 uart_parse_options(options, &baud, &parity, &bits, &flow);
599 return uart_set_options(&up->port, co, baud, parity, bits, flow);
602 static struct console ar933x_uart_console = {
603 .name = "ttyATH",
604 .write = ar933x_uart_console_write,
605 .device = uart_console_device,
606 .setup = ar933x_uart_console_setup,
607 .flags = CON_PRINTBUFFER,
608 .index = -1,
609 .data = &ar933x_uart_driver,
611 #endif /* CONFIG_SERIAL_AR933X_CONSOLE */
613 static struct uart_driver ar933x_uart_driver = {
614 .owner = THIS_MODULE,
615 .driver_name = DRIVER_NAME,
616 .dev_name = "ttyATH",
617 .nr = CONFIG_SERIAL_AR933X_NR_UARTS,
618 .cons = NULL, /* filled in runtime */
621 static int ar933x_uart_probe(struct platform_device *pdev)
623 struct ar933x_uart_port *up;
624 struct uart_port *port;
625 struct resource *mem_res;
626 struct resource *irq_res;
627 struct device_node *np;
628 unsigned int baud;
629 int id;
630 int ret;
632 np = pdev->dev.of_node;
633 if (IS_ENABLED(CONFIG_OF) && np) {
634 id = of_alias_get_id(np, "serial");
635 if (id < 0) {
636 dev_err(&pdev->dev, "unable to get alias id, err=%d\n",
637 id);
638 return id;
640 } else {
641 id = pdev->id;
642 if (id == -1)
643 id = 0;
646 if (id >= CONFIG_SERIAL_AR933X_NR_UARTS)
647 return -EINVAL;
649 irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
650 if (!irq_res) {
651 dev_err(&pdev->dev, "no IRQ resource\n");
652 return -EINVAL;
655 up = devm_kzalloc(&pdev->dev, sizeof(struct ar933x_uart_port),
656 GFP_KERNEL);
657 if (!up)
658 return -ENOMEM;
660 up->clk = devm_clk_get(&pdev->dev, "uart");
661 if (IS_ERR(up->clk)) {
662 dev_err(&pdev->dev, "unable to get UART clock\n");
663 return PTR_ERR(up->clk);
666 port = &up->port;
668 mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
669 port->membase = devm_ioremap_resource(&pdev->dev, mem_res);
670 if (IS_ERR(port->membase))
671 return PTR_ERR(port->membase);
673 ret = clk_prepare_enable(up->clk);
674 if (ret)
675 return ret;
677 port->uartclk = clk_get_rate(up->clk);
678 if (!port->uartclk) {
679 ret = -EINVAL;
680 goto err_disable_clk;
683 port->mapbase = mem_res->start;
684 port->line = id;
685 port->irq = irq_res->start;
686 port->dev = &pdev->dev;
687 port->type = PORT_AR933X;
688 port->iotype = UPIO_MEM32;
690 port->regshift = 2;
691 port->fifosize = AR933X_UART_FIFO_SIZE;
692 port->ops = &ar933x_uart_ops;
694 baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
695 up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD);
697 baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
698 up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);
700 #ifdef CONFIG_SERIAL_AR933X_CONSOLE
701 ar933x_console_ports[up->port.line] = up;
702 #endif
704 ret = uart_add_one_port(&ar933x_uart_driver, &up->port);
705 if (ret)
706 goto err_disable_clk;
708 platform_set_drvdata(pdev, up);
709 return 0;
711 err_disable_clk:
712 clk_disable_unprepare(up->clk);
713 return ret;
716 static int ar933x_uart_remove(struct platform_device *pdev)
718 struct ar933x_uart_port *up;
720 up = platform_get_drvdata(pdev);
722 if (up) {
723 uart_remove_one_port(&ar933x_uart_driver, &up->port);
724 clk_disable_unprepare(up->clk);
727 return 0;
730 #ifdef CONFIG_OF
731 static const struct of_device_id ar933x_uart_of_ids[] = {
732 { .compatible = "qca,ar9330-uart" },
735 MODULE_DEVICE_TABLE(of, ar933x_uart_of_ids);
736 #endif
738 static struct platform_driver ar933x_uart_platform_driver = {
739 .probe = ar933x_uart_probe,
740 .remove = ar933x_uart_remove,
741 .driver = {
742 .name = DRIVER_NAME,
743 .of_match_table = of_match_ptr(ar933x_uart_of_ids),
747 static int __init ar933x_uart_init(void)
749 int ret;
751 #ifdef CONFIG_SERIAL_AR933X_CONSOLE
752 ar933x_uart_driver.cons = &ar933x_uart_console;
753 #endif
755 ret = uart_register_driver(&ar933x_uart_driver);
756 if (ret)
757 goto err_out;
759 ret = platform_driver_register(&ar933x_uart_platform_driver);
760 if (ret)
761 goto err_unregister_uart_driver;
763 return 0;
765 err_unregister_uart_driver:
766 uart_unregister_driver(&ar933x_uart_driver);
767 err_out:
768 return ret;
771 static void __exit ar933x_uart_exit(void)
773 platform_driver_unregister(&ar933x_uart_platform_driver);
774 uart_unregister_driver(&ar933x_uart_driver);
777 module_init(ar933x_uart_init);
778 module_exit(ar933x_uart_exit);
780 MODULE_DESCRIPTION("Atheros AR933X UART driver");
781 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
782 MODULE_LICENSE("GPL v2");
783 MODULE_ALIAS("platform:" DRIVER_NAME);