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v3.1
 
  1/*
  2 * uartlite.c: Serial driver for Xilinx uartlite serial controller
  3 *
  4 * Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk>
  5 * Copyright (C) 2007 Secret Lab Technologies Ltd.
  6 *
  7 * This file is licensed under the terms of the GNU General Public License
  8 * version 2.  This program is licensed "as is" without any warranty of any
  9 * kind, whether express or implied.
 10 */
 11
 12#include <linux/platform_device.h>
 13#include <linux/module.h>
 
 14#include <linux/console.h>
 15#include <linux/serial.h>
 16#include <linux/serial_core.h>
 17#include <linux/tty.h>
 
 18#include <linux/delay.h>
 19#include <linux/interrupt.h>
 20#include <linux/init.h>
 21#include <asm/io.h>
 
 22#include <linux/of.h>
 23#include <linux/of_address.h>
 24#include <linux/of_device.h>
 25#include <linux/of_platform.h>
 26
 27#define ULITE_NAME		"ttyUL"
 
 
 
 
 28#define ULITE_MAJOR		204
 29#define ULITE_MINOR		187
 30#define ULITE_NR_UARTS		4
 
 31
 32/* ---------------------------------------------------------------------
 33 * Register definitions
 34 *
 35 * For register details see datasheet:
 36 * http://www.xilinx.com/support/documentation/ip_documentation/opb_uartlite.pdf 
 37 */
 38
 39#define ULITE_RX		0x00
 40#define ULITE_TX		0x04
 41#define ULITE_STATUS		0x08
 42#define ULITE_CONTROL		0x0c
 43
 44#define ULITE_REGION		16
 45
 46#define ULITE_STATUS_RXVALID	0x01
 47#define ULITE_STATUS_RXFULL	0x02
 48#define ULITE_STATUS_TXEMPTY	0x04
 49#define ULITE_STATUS_TXFULL	0x08
 50#define ULITE_STATUS_IE		0x10
 51#define ULITE_STATUS_OVERRUN	0x20
 52#define ULITE_STATUS_FRAME	0x40
 53#define ULITE_STATUS_PARITY	0x80
 54
 55#define ULITE_CONTROL_RST_TX	0x01
 56#define ULITE_CONTROL_RST_RX	0x02
 57#define ULITE_CONTROL_IE	0x10
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 58
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 59
 60static struct uart_port ulite_ports[ULITE_NR_UARTS];
 61
 
 
 62/* ---------------------------------------------------------------------
 63 * Core UART driver operations
 64 */
 65
 66static int ulite_receive(struct uart_port *port, int stat)
 67{
 68	struct tty_struct *tty = port->state->port.tty;
 69	unsigned char ch = 0;
 70	char flag = TTY_NORMAL;
 71
 72	if ((stat & (ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
 73		     | ULITE_STATUS_FRAME)) == 0)
 74		return 0;
 75
 76	/* stats */
 77	if (stat & ULITE_STATUS_RXVALID) {
 78		port->icount.rx++;
 79		ch = ioread32be(port->membase + ULITE_RX);
 80
 81		if (stat & ULITE_STATUS_PARITY)
 82			port->icount.parity++;
 83	}
 84
 85	if (stat & ULITE_STATUS_OVERRUN)
 86		port->icount.overrun++;
 87
 88	if (stat & ULITE_STATUS_FRAME)
 89		port->icount.frame++;
 90
 91
 92	/* drop byte with parity error if IGNPAR specificed */
 93	if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
 94		stat &= ~ULITE_STATUS_RXVALID;
 95
 96	stat &= port->read_status_mask;
 97
 98	if (stat & ULITE_STATUS_PARITY)
 99		flag = TTY_PARITY;
100
101
102	stat &= ~port->ignore_status_mask;
103
104	if (stat & ULITE_STATUS_RXVALID)
105		tty_insert_flip_char(tty, ch, flag);
106
107	if (stat & ULITE_STATUS_FRAME)
108		tty_insert_flip_char(tty, 0, TTY_FRAME);
109
110	if (stat & ULITE_STATUS_OVERRUN)
111		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
112
113	return 1;
114}
115
116static int ulite_transmit(struct uart_port *port, int stat)
117{
118	struct circ_buf *xmit  = &port->state->xmit;
 
119
120	if (stat & ULITE_STATUS_TXFULL)
121		return 0;
122
123	if (port->x_char) {
124		iowrite32be(port->x_char, port->membase + ULITE_TX);
125		port->x_char = 0;
126		port->icount.tx++;
127		return 1;
128	}
129
130	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
 
 
 
131		return 0;
132
133	iowrite32be(xmit->buf[xmit->tail], port->membase + ULITE_TX);
134	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
135	port->icount.tx++;
136
137	/* wake up */
138	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
139		uart_write_wakeup(port);
140
141	return 1;
142}
143
144static irqreturn_t ulite_isr(int irq, void *dev_id)
145{
146	struct uart_port *port = dev_id;
147	int busy, n = 0;
 
148
149	do {
150		int stat = ioread32be(port->membase + ULITE_STATUS);
 
151		busy  = ulite_receive(port, stat);
152		busy |= ulite_transmit(port, stat);
 
153		n++;
154	} while (busy);
155
156	/* work done? */
157	if (n > 1) {
158		tty_flip_buffer_push(port->state->port.tty);
159		return IRQ_HANDLED;
160	} else {
161		return IRQ_NONE;
162	}
163}
164
165static unsigned int ulite_tx_empty(struct uart_port *port)
166{
167	unsigned long flags;
168	unsigned int ret;
169
170	spin_lock_irqsave(&port->lock, flags);
171	ret = ioread32be(port->membase + ULITE_STATUS);
172	spin_unlock_irqrestore(&port->lock, flags);
173
174	return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
175}
176
177static unsigned int ulite_get_mctrl(struct uart_port *port)
178{
179	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
180}
181
182static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
183{
184	/* N/A */
185}
186
187static void ulite_stop_tx(struct uart_port *port)
188{
189	/* N/A */
190}
191
192static void ulite_start_tx(struct uart_port *port)
193{
194	ulite_transmit(port, ioread32be(port->membase + ULITE_STATUS));
195}
196
197static void ulite_stop_rx(struct uart_port *port)
198{
199	/* don't forward any more data (like !CREAD) */
200	port->ignore_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
201		| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
202}
203
204static void ulite_enable_ms(struct uart_port *port)
205{
206	/* N/A */
207}
208
209static void ulite_break_ctl(struct uart_port *port, int ctl)
210{
211	/* N/A */
212}
213
214static int ulite_startup(struct uart_port *port)
215{
 
216	int ret;
217
218	ret = request_irq(port->irq, ulite_isr,
219			  IRQF_SHARED | IRQF_SAMPLE_RANDOM, "uartlite", port);
 
 
 
 
 
 
220	if (ret)
221		return ret;
222
223	iowrite32be(ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX,
224	       port->membase + ULITE_CONTROL);
225	iowrite32be(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL);
226
227	return 0;
228}
229
230static void ulite_shutdown(struct uart_port *port)
231{
232	iowrite32be(0, port->membase + ULITE_CONTROL);
233	ioread32be(port->membase + ULITE_CONTROL); /* dummy */
 
 
234	free_irq(port->irq, port);
 
235}
236
237static void ulite_set_termios(struct uart_port *port, struct ktermios *termios,
238			      struct ktermios *old)
 
239{
240	unsigned long flags;
241	unsigned int baud;
242
243	spin_lock_irqsave(&port->lock, flags);
 
 
 
 
 
 
244
245	port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
246		| ULITE_STATUS_TXFULL;
247
248	if (termios->c_iflag & INPCK)
249		port->read_status_mask |=
250			ULITE_STATUS_PARITY | ULITE_STATUS_FRAME;
251
252	port->ignore_status_mask = 0;
253	if (termios->c_iflag & IGNPAR)
254		port->ignore_status_mask |= ULITE_STATUS_PARITY
255			| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
256
257	/* ignore all characters if CREAD is not set */
258	if ((termios->c_cflag & CREAD) == 0)
259		port->ignore_status_mask |=
260			ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
261			| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
262
263	/* update timeout */
264	baud = uart_get_baud_rate(port, termios, old, 0, 460800);
265	uart_update_timeout(port, termios->c_cflag, baud);
266
267	spin_unlock_irqrestore(&port->lock, flags);
268}
269
270static const char *ulite_type(struct uart_port *port)
271{
272	return port->type == PORT_UARTLITE ? "uartlite" : NULL;
273}
274
275static void ulite_release_port(struct uart_port *port)
276{
277	release_mem_region(port->mapbase, ULITE_REGION);
278	iounmap(port->membase);
279	port->membase = NULL;
280}
281
282static int ulite_request_port(struct uart_port *port)
283{
 
 
 
284	pr_debug("ulite console: port=%p; port->mapbase=%llx\n",
285		 port, (unsigned long long) port->mapbase);
286
287	if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
288		dev_err(port->dev, "Memory region busy\n");
289		return -EBUSY;
290	}
291
292	port->membase = ioremap(port->mapbase, ULITE_REGION);
293	if (!port->membase) {
294		dev_err(port->dev, "Unable to map registers\n");
295		release_mem_region(port->mapbase, ULITE_REGION);
296		return -EBUSY;
297	}
298
 
 
 
 
 
 
 
 
299	return 0;
300}
301
302static void ulite_config_port(struct uart_port *port, int flags)
303{
304	if (!ulite_request_port(port))
305		port->type = PORT_UARTLITE;
306}
307
308static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
309{
310	/* we don't want the core code to modify any port params */
311	return -EINVAL;
312}
313
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
314#ifdef CONFIG_CONSOLE_POLL
315static int ulite_get_poll_char(struct uart_port *port)
316{
317	if (!(ioread32be(port->membase + ULITE_STATUS)
318						& ULITE_STATUS_RXVALID))
319		return NO_POLL_CHAR;
320
321	return ioread32be(port->membase + ULITE_RX);
322}
323
324static void ulite_put_poll_char(struct uart_port *port, unsigned char ch)
325{
326	while (ioread32be(port->membase + ULITE_STATUS) & ULITE_STATUS_TXFULL)
327		cpu_relax();
328
329	/* write char to device */
330	iowrite32be(ch, port->membase + ULITE_TX);
331}
332#endif
333
334static struct uart_ops ulite_ops = {
335	.tx_empty	= ulite_tx_empty,
336	.set_mctrl	= ulite_set_mctrl,
337	.get_mctrl	= ulite_get_mctrl,
338	.stop_tx	= ulite_stop_tx,
339	.start_tx	= ulite_start_tx,
340	.stop_rx	= ulite_stop_rx,
341	.enable_ms	= ulite_enable_ms,
342	.break_ctl	= ulite_break_ctl,
343	.startup	= ulite_startup,
344	.shutdown	= ulite_shutdown,
345	.set_termios	= ulite_set_termios,
346	.type		= ulite_type,
347	.release_port	= ulite_release_port,
348	.request_port	= ulite_request_port,
349	.config_port	= ulite_config_port,
350	.verify_port	= ulite_verify_port,
 
351#ifdef CONFIG_CONSOLE_POLL
352	.poll_get_char	= ulite_get_poll_char,
353	.poll_put_char	= ulite_put_poll_char,
354#endif
355};
356
357/* ---------------------------------------------------------------------
358 * Console driver operations
359 */
360
361#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
362static void ulite_console_wait_tx(struct uart_port *port)
363{
364	int i;
365	u8 val;
366
367	/* Spin waiting for TX fifo to have space available */
368	for (i = 0; i < 100000; i++) {
369		val = ioread32be(port->membase + ULITE_STATUS);
370		if ((val & ULITE_STATUS_TXFULL) == 0)
371			break;
372		cpu_relax();
373	}
 
374}
375
376static void ulite_console_putchar(struct uart_port *port, int ch)
377{
378	ulite_console_wait_tx(port);
379	iowrite32be(ch, port->membase + ULITE_TX);
380}
381
382static void ulite_console_write(struct console *co, const char *s,
383				unsigned int count)
384{
385	struct uart_port *port = &ulite_ports[co->index];
386	unsigned long flags;
387	unsigned int ier;
388	int locked = 1;
389
390	if (oops_in_progress) {
391		locked = spin_trylock_irqsave(&port->lock, flags);
392	} else
393		spin_lock_irqsave(&port->lock, flags);
394
395	/* save and disable interrupt */
396	ier = ioread32be(port->membase + ULITE_STATUS) & ULITE_STATUS_IE;
397	iowrite32be(0, port->membase + ULITE_CONTROL);
398
399	uart_console_write(port, s, count, ulite_console_putchar);
400
401	ulite_console_wait_tx(port);
402
403	/* restore interrupt state */
404	if (ier)
405		iowrite32be(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL);
406
407	if (locked)
408		spin_unlock_irqrestore(&port->lock, flags);
409}
410
411static int __devinit ulite_console_setup(struct console *co, char *options)
412{
413	struct uart_port *port;
414	int baud = 9600;
415	int bits = 8;
416	int parity = 'n';
417	int flow = 'n';
418
419	if (co->index < 0 || co->index >= ULITE_NR_UARTS)
420		return -EINVAL;
421
422	port = &ulite_ports[co->index];
423
424	/* Has the device been initialized yet? */
425	if (!port->mapbase) {
426		pr_debug("console on ttyUL%i not present\n", co->index);
427		return -ENODEV;
428	}
429
 
 
430	/* not initialized yet? */
431	if (!port->membase) {
432		if (ulite_request_port(port))
433			return -ENODEV;
434	}
435
436	if (options)
437		uart_parse_options(options, &baud, &parity, &bits, &flow);
438
439	return uart_set_options(port, co, baud, parity, bits, flow);
440}
441
442static struct uart_driver ulite_uart_driver;
443
444static struct console ulite_console = {
445	.name	= ULITE_NAME,
446	.write	= ulite_console_write,
447	.device	= uart_console_device,
448	.setup	= ulite_console_setup,
449	.flags	= CON_PRINTBUFFER,
450	.index	= -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
451	.data	= &ulite_uart_driver,
452};
453
454static int __init ulite_console_init(void)
455{
456	register_console(&ulite_console);
457	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
458}
459
460console_initcall(ulite_console_init);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
461
462#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */
463
464static struct uart_driver ulite_uart_driver = {
465	.owner		= THIS_MODULE,
466	.driver_name	= "uartlite",
467	.dev_name	= ULITE_NAME,
468	.major		= ULITE_MAJOR,
469	.minor		= ULITE_MINOR,
470	.nr		= ULITE_NR_UARTS,
471#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
472	.cons		= &ulite_console,
473#endif
474};
475
476/* ---------------------------------------------------------------------
477 * Port assignment functions (mapping devices to uart_port structures)
478 */
479
480/** ulite_assign: register a uartlite device with the driver
481 *
482 * @dev: pointer to device structure
483 * @id: requested id number.  Pass -1 for automatic port assignment
484 * @base: base address of uartlite registers
485 * @irq: irq number for uartlite
 
486 *
487 * Returns: 0 on success, <0 otherwise
488 */
489static int __devinit ulite_assign(struct device *dev, int id, u32 base, int irq)
 
490{
491	struct uart_port *port;
492	int rc;
493
494	/* if id = -1; then scan for a free id and use that */
495	if (id < 0) {
496		for (id = 0; id < ULITE_NR_UARTS; id++)
497			if (ulite_ports[id].mapbase == 0)
498				break;
499	}
500	if (id < 0 || id >= ULITE_NR_UARTS) {
501		dev_err(dev, "%s%i too large\n", ULITE_NAME, id);
502		return -EINVAL;
503	}
504
505	if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) {
506		dev_err(dev, "cannot assign to %s%i; it is already in use\n",
507			ULITE_NAME, id);
508		return -EBUSY;
509	}
510
511	port = &ulite_ports[id];
512
513	spin_lock_init(&port->lock);
514	port->fifosize = 16;
515	port->regshift = 2;
516	port->iotype = UPIO_MEM;
517	port->iobase = 1; /* mark port in use */
518	port->mapbase = base;
519	port->membase = NULL;
520	port->ops = &ulite_ops;
521	port->irq = irq;
522	port->flags = UPF_BOOT_AUTOCONF;
523	port->dev = dev;
524	port->type = PORT_UNKNOWN;
525	port->line = id;
 
526
527	dev_set_drvdata(dev, port);
528
529	/* Register the port */
530	rc = uart_add_one_port(&ulite_uart_driver, port);
531	if (rc) {
532		dev_err(dev, "uart_add_one_port() failed; err=%i\n", rc);
533		port->mapbase = 0;
534		dev_set_drvdata(dev, NULL);
535		return rc;
536	}
537
538	return 0;
539}
540
541/** ulite_release: register a uartlite device with the driver
542 *
543 * @dev: pointer to device structure
544 */
545static int __devexit ulite_release(struct device *dev)
546{
547	struct uart_port *port = dev_get_drvdata(dev);
548	int rc = 0;
549
550	if (port) {
551		rc = uart_remove_one_port(&ulite_uart_driver, port);
552		dev_set_drvdata(dev, NULL);
553		port->mapbase = 0;
554	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
555
556	return rc;
 
 
 
 
 
557}
558
559/* ---------------------------------------------------------------------
560 * Platform bus binding
561 */
562
 
 
 
 
 
 
563#if defined(CONFIG_OF)
564/* Match table for of_platform binding */
565static struct of_device_id ulite_of_match[] __devinitdata = {
566	{ .compatible = "xlnx,opb-uartlite-1.00.b", },
567	{ .compatible = "xlnx,xps-uartlite-1.00.a", },
568	{}
569};
570MODULE_DEVICE_TABLE(of, ulite_of_match);
571#else /* CONFIG_OF */
572#define ulite_of_match NULL
573#endif /* CONFIG_OF */
574
575static int __devinit ulite_probe(struct platform_device *pdev)
576{
577	struct resource *res, *res2;
 
 
578	int id = pdev->id;
579#ifdef CONFIG_OF
580	const __be32 *prop;
581
582	prop = of_get_property(pdev->dev.of_node, "port-number", NULL);
583	if (prop)
584		id = be32_to_cpup(prop);
585#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
586
587	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
588	if (!res)
589		return -ENODEV;
590
591	res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
592	if (!res2)
593		return -ENODEV;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
594
595	return ulite_assign(&pdev->dev, id, res->start, res2->start);
 
 
 
 
 
596}
597
598static int __devexit ulite_remove(struct platform_device *pdev)
599{
600	return ulite_release(&pdev->dev);
 
 
 
 
 
 
 
601}
602
603/* work with hotplug and coldplug */
604MODULE_ALIAS("platform:uartlite");
605
606static struct platform_driver ulite_platform_driver = {
607	.probe = ulite_probe,
608	.remove = __devexit_p(ulite_remove),
609	.driver = {
610		.owner = THIS_MODULE,
611		.name  = "uartlite",
612		.of_match_table = ulite_of_match,
 
613	},
614};
615
616/* ---------------------------------------------------------------------
617 * Module setup/teardown
618 */
619
620int __init ulite_init(void)
621{
622	int ret;
623
624	pr_debug("uartlite: calling uart_register_driver()\n");
625	ret = uart_register_driver(&ulite_uart_driver);
626	if (ret)
627		goto err_uart;
628
629	pr_debug("uartlite: calling platform_driver_register()\n");
630	ret = platform_driver_register(&ulite_platform_driver);
631	if (ret)
632		goto err_plat;
633
634	return 0;
635
636err_plat:
637	uart_unregister_driver(&ulite_uart_driver);
638err_uart:
639	printk(KERN_ERR "registering uartlite driver failed: err=%i", ret);
640	return ret;
641}
642
643void __exit ulite_exit(void)
644{
645	platform_driver_unregister(&ulite_platform_driver);
646	uart_unregister_driver(&ulite_uart_driver);
 
647}
648
649module_init(ulite_init);
650module_exit(ulite_exit);
651
652MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
653MODULE_DESCRIPTION("Xilinx uartlite serial driver");
654MODULE_LICENSE("GPL");
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * uartlite.c: Serial driver for Xilinx uartlite serial controller
  4 *
  5 * Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk>
  6 * Copyright (C) 2007 Secret Lab Technologies Ltd.
 
 
 
 
  7 */
  8
  9#include <linux/platform_device.h>
 10#include <linux/module.h>
 11#include <linux/bitfield.h>
 12#include <linux/console.h>
 13#include <linux/serial.h>
 14#include <linux/serial_core.h>
 15#include <linux/tty.h>
 16#include <linux/tty_flip.h>
 17#include <linux/delay.h>
 18#include <linux/interrupt.h>
 19#include <linux/init.h>
 20#include <linux/io.h>
 21#include <linux/iopoll.h>
 22#include <linux/of.h>
 23#include <linux/clk.h>
 24#include <linux/pm_runtime.h>
 
 25
 26#define ULITE_NAME		"ttyUL"
 27#if CONFIG_SERIAL_UARTLITE_NR_UARTS > 4
 28#define ULITE_MAJOR             0       /* use dynamic node allocation */
 29#define ULITE_MINOR             0
 30#else
 31#define ULITE_MAJOR		204
 32#define ULITE_MINOR		187
 33#endif
 34#define ULITE_NR_UARTS		CONFIG_SERIAL_UARTLITE_NR_UARTS
 35
 36/* ---------------------------------------------------------------------
 37 * Register definitions
 38 *
 39 * For register details see datasheet:
 40 * https://www.xilinx.com/support/documentation/ip_documentation/opb_uartlite.pdf
 41 */
 42
 43#define ULITE_RX		0x00
 44#define ULITE_TX		0x04
 45#define ULITE_STATUS		0x08
 46#define ULITE_CONTROL		0x0c
 47
 48#define ULITE_REGION		16
 49
 50#define ULITE_STATUS_RXVALID	0x01
 51#define ULITE_STATUS_RXFULL	0x02
 52#define ULITE_STATUS_TXEMPTY	0x04
 53#define ULITE_STATUS_TXFULL	0x08
 54#define ULITE_STATUS_IE		0x10
 55#define ULITE_STATUS_OVERRUN	0x20
 56#define ULITE_STATUS_FRAME	0x40
 57#define ULITE_STATUS_PARITY	0x80
 58
 59#define ULITE_CONTROL_RST_TX	0x01
 60#define ULITE_CONTROL_RST_RX	0x02
 61#define ULITE_CONTROL_IE	0x10
 62#define UART_AUTOSUSPEND_TIMEOUT	3000	/* ms */
 63
 64/* Static pointer to console port */
 65#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
 66static struct uart_port *console_port;
 67#endif
 68
 69/**
 70 * struct uartlite_data - Driver private data
 71 * @reg_ops: Functions to read/write registers
 72 * @clk: Our parent clock, if present
 73 * @baud: The baud rate configured when this device was synthesized
 74 * @cflags: The cflags for parity and data bits
 75 */
 76struct uartlite_data {
 77	const struct uartlite_reg_ops *reg_ops;
 78	struct clk *clk;
 79	unsigned int baud;
 80	tcflag_t cflags;
 81};
 82
 83struct uartlite_reg_ops {
 84	u32 (*in)(void __iomem *addr);
 85	void (*out)(u32 val, void __iomem *addr);
 86};
 87
 88static u32 uartlite_inbe32(void __iomem *addr)
 89{
 90	return ioread32be(addr);
 91}
 92
 93static void uartlite_outbe32(u32 val, void __iomem *addr)
 94{
 95	iowrite32be(val, addr);
 96}
 97
 98static const struct uartlite_reg_ops uartlite_be = {
 99	.in = uartlite_inbe32,
100	.out = uartlite_outbe32,
101};
102
103static u32 uartlite_inle32(void __iomem *addr)
104{
105	return ioread32(addr);
106}
107
108static void uartlite_outle32(u32 val, void __iomem *addr)
109{
110	iowrite32(val, addr);
111}
112
113static const struct uartlite_reg_ops uartlite_le = {
114	.in = uartlite_inle32,
115	.out = uartlite_outle32,
116};
117
118static inline u32 uart_in32(u32 offset, struct uart_port *port)
119{
120	struct uartlite_data *pdata = port->private_data;
121
122	return pdata->reg_ops->in(port->membase + offset);
123}
124
125static inline void uart_out32(u32 val, u32 offset, struct uart_port *port)
126{
127	struct uartlite_data *pdata = port->private_data;
128
129	pdata->reg_ops->out(val, port->membase + offset);
130}
131
132static struct uart_port ulite_ports[ULITE_NR_UARTS];
133
134static struct uart_driver ulite_uart_driver;
135
136/* ---------------------------------------------------------------------
137 * Core UART driver operations
138 */
139
140static int ulite_receive(struct uart_port *port, int stat)
141{
142	struct tty_port *tport = &port->state->port;
143	unsigned char ch = 0;
144	char flag = TTY_NORMAL;
145
146	if ((stat & (ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
147		     | ULITE_STATUS_FRAME)) == 0)
148		return 0;
149
150	/* stats */
151	if (stat & ULITE_STATUS_RXVALID) {
152		port->icount.rx++;
153		ch = uart_in32(ULITE_RX, port);
154
155		if (stat & ULITE_STATUS_PARITY)
156			port->icount.parity++;
157	}
158
159	if (stat & ULITE_STATUS_OVERRUN)
160		port->icount.overrun++;
161
162	if (stat & ULITE_STATUS_FRAME)
163		port->icount.frame++;
164
165
166	/* drop byte with parity error if IGNPAR specificed */
167	if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
168		stat &= ~ULITE_STATUS_RXVALID;
169
170	stat &= port->read_status_mask;
171
172	if (stat & ULITE_STATUS_PARITY)
173		flag = TTY_PARITY;
174
175
176	stat &= ~port->ignore_status_mask;
177
178	if (stat & ULITE_STATUS_RXVALID)
179		tty_insert_flip_char(tport, ch, flag);
180
181	if (stat & ULITE_STATUS_FRAME)
182		tty_insert_flip_char(tport, 0, TTY_FRAME);
183
184	if (stat & ULITE_STATUS_OVERRUN)
185		tty_insert_flip_char(tport, 0, TTY_OVERRUN);
186
187	return 1;
188}
189
190static int ulite_transmit(struct uart_port *port, int stat)
191{
192	struct tty_port *tport = &port->state->port;
193	unsigned char ch;
194
195	if (stat & ULITE_STATUS_TXFULL)
196		return 0;
197
198	if (port->x_char) {
199		uart_out32(port->x_char, ULITE_TX, port);
200		port->x_char = 0;
201		port->icount.tx++;
202		return 1;
203	}
204
205	if (uart_tx_stopped(port))
206		return 0;
207
208	if (!uart_fifo_get(port, &ch))
209		return 0;
210
211	uart_out32(ch, ULITE_TX, port);
 
 
212
213	/* wake up */
214	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
215		uart_write_wakeup(port);
216
217	return 1;
218}
219
220static irqreturn_t ulite_isr(int irq, void *dev_id)
221{
222	struct uart_port *port = dev_id;
223	int stat, busy, n = 0;
224	unsigned long flags;
225
226	do {
227		uart_port_lock_irqsave(port, &flags);
228		stat = uart_in32(ULITE_STATUS, port);
229		busy  = ulite_receive(port, stat);
230		busy |= ulite_transmit(port, stat);
231		uart_port_unlock_irqrestore(port, flags);
232		n++;
233	} while (busy);
234
235	/* work done? */
236	if (n > 1) {
237		tty_flip_buffer_push(&port->state->port);
238		return IRQ_HANDLED;
239	} else {
240		return IRQ_NONE;
241	}
242}
243
244static unsigned int ulite_tx_empty(struct uart_port *port)
245{
246	unsigned long flags;
247	unsigned int ret;
248
249	uart_port_lock_irqsave(port, &flags);
250	ret = uart_in32(ULITE_STATUS, port);
251	uart_port_unlock_irqrestore(port, flags);
252
253	return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
254}
255
256static unsigned int ulite_get_mctrl(struct uart_port *port)
257{
258	return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
259}
260
261static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
262{
263	/* N/A */
264}
265
266static void ulite_stop_tx(struct uart_port *port)
267{
268	/* N/A */
269}
270
271static void ulite_start_tx(struct uart_port *port)
272{
273	ulite_transmit(port, uart_in32(ULITE_STATUS, port));
274}
275
276static void ulite_stop_rx(struct uart_port *port)
277{
278	/* don't forward any more data (like !CREAD) */
279	port->ignore_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
280		| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
281}
282
 
 
 
 
 
283static void ulite_break_ctl(struct uart_port *port, int ctl)
284{
285	/* N/A */
286}
287
288static int ulite_startup(struct uart_port *port)
289{
290	struct uartlite_data *pdata = port->private_data;
291	int ret;
292
293	ret = clk_enable(pdata->clk);
294	if (ret) {
295		dev_err(port->dev, "Failed to enable clock\n");
296		return ret;
297	}
298
299	ret = request_irq(port->irq, ulite_isr, IRQF_SHARED | IRQF_TRIGGER_RISING,
300			  "uartlite", port);
301	if (ret)
302		return ret;
303
304	uart_out32(ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX,
305		ULITE_CONTROL, port);
306	uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
307
308	return 0;
309}
310
311static void ulite_shutdown(struct uart_port *port)
312{
313	struct uartlite_data *pdata = port->private_data;
314
315	uart_out32(0, ULITE_CONTROL, port);
316	uart_in32(ULITE_CONTROL, port); /* dummy */
317	free_irq(port->irq, port);
318	clk_disable(pdata->clk);
319}
320
321static void ulite_set_termios(struct uart_port *port,
322			      struct ktermios *termios,
323			      const struct ktermios *old)
324{
325	unsigned long flags;
326	struct uartlite_data *pdata = port->private_data;
327
328	/* Set termios to what the hardware supports */
329	termios->c_iflag &= ~BRKINT;
330	termios->c_cflag &= ~(CSTOPB | PARENB | PARODD | CSIZE);
331	termios->c_cflag |= pdata->cflags & (PARENB | PARODD | CSIZE);
332	tty_termios_encode_baud_rate(termios, pdata->baud, pdata->baud);
333
334	uart_port_lock_irqsave(port, &flags);
335
336	port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
337		| ULITE_STATUS_TXFULL;
338
339	if (termios->c_iflag & INPCK)
340		port->read_status_mask |=
341			ULITE_STATUS_PARITY | ULITE_STATUS_FRAME;
342
343	port->ignore_status_mask = 0;
344	if (termios->c_iflag & IGNPAR)
345		port->ignore_status_mask |= ULITE_STATUS_PARITY
346			| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
347
348	/* ignore all characters if CREAD is not set */
349	if ((termios->c_cflag & CREAD) == 0)
350		port->ignore_status_mask |=
351			ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
352			| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
353
354	/* update timeout */
355	uart_update_timeout(port, termios->c_cflag, pdata->baud);
 
356
357	uart_port_unlock_irqrestore(port, flags);
358}
359
360static const char *ulite_type(struct uart_port *port)
361{
362	return port->type == PORT_UARTLITE ? "uartlite" : NULL;
363}
364
365static void ulite_release_port(struct uart_port *port)
366{
367	release_mem_region(port->mapbase, ULITE_REGION);
368	iounmap(port->membase);
369	port->membase = NULL;
370}
371
372static int ulite_request_port(struct uart_port *port)
373{
374	struct uartlite_data *pdata = port->private_data;
375	int ret;
376
377	pr_debug("ulite console: port=%p; port->mapbase=%llx\n",
378		 port, (unsigned long long) port->mapbase);
379
380	if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
381		dev_err(port->dev, "Memory region busy\n");
382		return -EBUSY;
383	}
384
385	port->membase = ioremap(port->mapbase, ULITE_REGION);
386	if (!port->membase) {
387		dev_err(port->dev, "Unable to map registers\n");
388		release_mem_region(port->mapbase, ULITE_REGION);
389		return -EBUSY;
390	}
391
392	pdata->reg_ops = &uartlite_be;
393	ret = uart_in32(ULITE_CONTROL, port);
394	uart_out32(ULITE_CONTROL_RST_TX, ULITE_CONTROL, port);
395	ret = uart_in32(ULITE_STATUS, port);
396	/* Endianess detection */
397	if ((ret & ULITE_STATUS_TXEMPTY) != ULITE_STATUS_TXEMPTY)
398		pdata->reg_ops = &uartlite_le;
399
400	return 0;
401}
402
403static void ulite_config_port(struct uart_port *port, int flags)
404{
405	if (!ulite_request_port(port))
406		port->type = PORT_UARTLITE;
407}
408
409static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
410{
411	/* we don't want the core code to modify any port params */
412	return -EINVAL;
413}
414
415static void ulite_pm(struct uart_port *port, unsigned int state,
416		     unsigned int oldstate)
417{
418	int ret;
419
420	if (!state) {
421		ret = pm_runtime_get_sync(port->dev);
422		if (ret < 0)
423			dev_err(port->dev, "Failed to enable clocks\n");
424	} else {
425		pm_runtime_mark_last_busy(port->dev);
426		pm_runtime_put_autosuspend(port->dev);
427	}
428}
429
430#ifdef CONFIG_CONSOLE_POLL
431static int ulite_get_poll_char(struct uart_port *port)
432{
433	if (!(uart_in32(ULITE_STATUS, port) & ULITE_STATUS_RXVALID))
 
434		return NO_POLL_CHAR;
435
436	return uart_in32(ULITE_RX, port);
437}
438
439static void ulite_put_poll_char(struct uart_port *port, unsigned char ch)
440{
441	while (uart_in32(ULITE_STATUS, port) & ULITE_STATUS_TXFULL)
442		cpu_relax();
443
444	/* write char to device */
445	uart_out32(ch, ULITE_TX, port);
446}
447#endif
448
449static const struct uart_ops ulite_ops = {
450	.tx_empty	= ulite_tx_empty,
451	.set_mctrl	= ulite_set_mctrl,
452	.get_mctrl	= ulite_get_mctrl,
453	.stop_tx	= ulite_stop_tx,
454	.start_tx	= ulite_start_tx,
455	.stop_rx	= ulite_stop_rx,
 
456	.break_ctl	= ulite_break_ctl,
457	.startup	= ulite_startup,
458	.shutdown	= ulite_shutdown,
459	.set_termios	= ulite_set_termios,
460	.type		= ulite_type,
461	.release_port	= ulite_release_port,
462	.request_port	= ulite_request_port,
463	.config_port	= ulite_config_port,
464	.verify_port	= ulite_verify_port,
465	.pm		= ulite_pm,
466#ifdef CONFIG_CONSOLE_POLL
467	.poll_get_char	= ulite_get_poll_char,
468	.poll_put_char	= ulite_put_poll_char,
469#endif
470};
471
472/* ---------------------------------------------------------------------
473 * Console driver operations
474 */
475
476#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
477static void ulite_console_wait_tx(struct uart_port *port)
478{
 
479	u8 val;
480
481	/*
482	 * Spin waiting for TX fifo to have space available.
483	 * When using the Microblaze Debug Module this can take up to 1s
484	 */
485	if (read_poll_timeout_atomic(uart_in32, val, !(val & ULITE_STATUS_TXFULL),
486				     0, 1000000, false, ULITE_STATUS, port))
487		dev_warn(port->dev,
488			 "timeout waiting for TX buffer empty\n");
489}
490
491static void ulite_console_putchar(struct uart_port *port, unsigned char ch)
492{
493	ulite_console_wait_tx(port);
494	uart_out32(ch, ULITE_TX, port);
495}
496
497static void ulite_console_write(struct console *co, const char *s,
498				unsigned int count)
499{
500	struct uart_port *port = console_port;
501	unsigned long flags;
502	unsigned int ier;
503	int locked = 1;
504
505	if (oops_in_progress) {
506		locked = uart_port_trylock_irqsave(port, &flags);
507	} else
508		uart_port_lock_irqsave(port, &flags);
509
510	/* save and disable interrupt */
511	ier = uart_in32(ULITE_STATUS, port) & ULITE_STATUS_IE;
512	uart_out32(0, ULITE_CONTROL, port);
513
514	uart_console_write(port, s, count, ulite_console_putchar);
515
516	ulite_console_wait_tx(port);
517
518	/* restore interrupt state */
519	if (ier)
520		uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
521
522	if (locked)
523		uart_port_unlock_irqrestore(port, flags);
524}
525
526static int ulite_console_setup(struct console *co, char *options)
527{
528	struct uart_port *port = NULL;
529	int baud = 9600;
530	int bits = 8;
531	int parity = 'n';
532	int flow = 'n';
533
534	if (co->index >= 0 && co->index < ULITE_NR_UARTS)
535		port = ulite_ports + co->index;
 
 
536
537	/* Has the device been initialized yet? */
538	if (!port || !port->mapbase) {
539		pr_debug("console on ttyUL%i not present\n", co->index);
540		return -ENODEV;
541	}
542
543	console_port = port;
544
545	/* not initialized yet? */
546	if (!port->membase) {
547		if (ulite_request_port(port))
548			return -ENODEV;
549	}
550
551	if (options)
552		uart_parse_options(options, &baud, &parity, &bits, &flow);
553
554	return uart_set_options(port, co, baud, parity, bits, flow);
555}
556
 
 
557static struct console ulite_console = {
558	.name	= ULITE_NAME,
559	.write	= ulite_console_write,
560	.device	= uart_console_device,
561	.setup	= ulite_console_setup,
562	.flags	= CON_PRINTBUFFER,
563	.index	= -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
564	.data	= &ulite_uart_driver,
565};
566
567static void early_uartlite_putc(struct uart_port *port, unsigned char c)
568{
569	/*
570	 * Limit how many times we'll spin waiting for TX FIFO status.
571	 * This will prevent lockups if the base address is incorrectly
572	 * set, or any other issue on the UARTLITE.
573	 * This limit is pretty arbitrary, unless we are at about 10 baud
574	 * we'll never timeout on a working UART.
575	 */
576	unsigned retries = 1000000;
577
578	while (--retries &&
579	       (readl(port->membase + ULITE_STATUS) & ULITE_STATUS_TXFULL))
580		;
581
582	/* Only attempt the iowrite if we didn't timeout */
583	if (retries)
584		writel(c & 0xff, port->membase + ULITE_TX);
585}
586
587static void early_uartlite_write(struct console *console,
588				 const char *s, unsigned n)
589{
590	struct earlycon_device *device = console->data;
591	uart_console_write(&device->port, s, n, early_uartlite_putc);
592}
593
594static int __init early_uartlite_setup(struct earlycon_device *device,
595				       const char *options)
596{
597	if (!device->port.membase)
598		return -ENODEV;
599
600	device->con->write = early_uartlite_write;
601	return 0;
602}
603EARLYCON_DECLARE(uartlite, early_uartlite_setup);
604OF_EARLYCON_DECLARE(uartlite_b, "xlnx,opb-uartlite-1.00.b", early_uartlite_setup);
605OF_EARLYCON_DECLARE(uartlite_a, "xlnx,xps-uartlite-1.00.a", early_uartlite_setup);
606
607#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */
608
609static struct uart_driver ulite_uart_driver = {
610	.owner		= THIS_MODULE,
611	.driver_name	= "uartlite",
612	.dev_name	= ULITE_NAME,
613	.major		= ULITE_MAJOR,
614	.minor		= ULITE_MINOR,
615	.nr		= ULITE_NR_UARTS,
616#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
617	.cons		= &ulite_console,
618#endif
619};
620
621/* ---------------------------------------------------------------------
622 * Port assignment functions (mapping devices to uart_port structures)
623 */
624
625/** ulite_assign: register a uartlite device with the driver
626 *
627 * @dev: pointer to device structure
628 * @id: requested id number.  Pass -1 for automatic port assignment
629 * @base: base address of uartlite registers
630 * @irq: irq number for uartlite
631 * @pdata: private data for uartlite
632 *
633 * Returns: 0 on success, <0 otherwise
634 */
635static int ulite_assign(struct device *dev, int id, phys_addr_t base, int irq,
636			struct uartlite_data *pdata)
637{
638	struct uart_port *port;
639	int rc;
640
641	/* if id = -1; then scan for a free id and use that */
642	if (id < 0) {
643		for (id = 0; id < ULITE_NR_UARTS; id++)
644			if (ulite_ports[id].mapbase == 0)
645				break;
646	}
647	if (id < 0 || id >= ULITE_NR_UARTS) {
648		dev_err(dev, "%s%i too large\n", ULITE_NAME, id);
649		return -EINVAL;
650	}
651
652	if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) {
653		dev_err(dev, "cannot assign to %s%i; it is already in use\n",
654			ULITE_NAME, id);
655		return -EBUSY;
656	}
657
658	port = &ulite_ports[id];
659
660	spin_lock_init(&port->lock);
661	port->fifosize = 16;
662	port->regshift = 2;
663	port->iotype = UPIO_MEM;
664	port->iobase = 1; /* mark port in use */
665	port->mapbase = base;
666	port->membase = NULL;
667	port->ops = &ulite_ops;
668	port->irq = irq;
669	port->flags = UPF_BOOT_AUTOCONF;
670	port->dev = dev;
671	port->type = PORT_UNKNOWN;
672	port->line = id;
673	port->private_data = pdata;
674
675	dev_set_drvdata(dev, port);
676
677	/* Register the port */
678	rc = uart_add_one_port(&ulite_uart_driver, port);
679	if (rc) {
680		dev_err(dev, "uart_add_one_port() failed; err=%i\n", rc);
681		port->mapbase = 0;
682		dev_set_drvdata(dev, NULL);
683		return rc;
684	}
685
686	return 0;
687}
688
689/** ulite_release: register a uartlite device with the driver
690 *
691 * @dev: pointer to device structure
692 */
693static void ulite_release(struct device *dev)
694{
695	struct uart_port *port = dev_get_drvdata(dev);
 
696
697	if (port) {
698		uart_remove_one_port(&ulite_uart_driver, port);
699		dev_set_drvdata(dev, NULL);
700		port->mapbase = 0;
701	}
702}
703
704/**
705 * ulite_suspend - Stop the device.
706 *
707 * @dev: handle to the device structure.
708 * Return: 0 always.
709 */
710static int __maybe_unused ulite_suspend(struct device *dev)
711{
712	struct uart_port *port = dev_get_drvdata(dev);
713
714	if (port)
715		uart_suspend_port(&ulite_uart_driver, port);
716
717	return 0;
718}
719
720/**
721 * ulite_resume - Resume the device.
722 *
723 * @dev: handle to the device structure.
724 * Return: 0 on success, errno otherwise.
725 */
726static int __maybe_unused ulite_resume(struct device *dev)
727{
728	struct uart_port *port = dev_get_drvdata(dev);
729
730	if (port)
731		uart_resume_port(&ulite_uart_driver, port);
732
733	return 0;
734}
735
736static int __maybe_unused ulite_runtime_suspend(struct device *dev)
737{
738	struct uart_port *port = dev_get_drvdata(dev);
739	struct uartlite_data *pdata = port->private_data;
740
741	clk_disable(pdata->clk);
742	return 0;
743};
744
745static int __maybe_unused ulite_runtime_resume(struct device *dev)
746{
747	struct uart_port *port = dev_get_drvdata(dev);
748	struct uartlite_data *pdata = port->private_data;
749	int ret;
750
751	ret = clk_enable(pdata->clk);
752	if (ret) {
753		dev_err(dev, "Cannot enable clock.\n");
754		return ret;
755	}
756	return 0;
757}
758
759/* ---------------------------------------------------------------------
760 * Platform bus binding
761 */
762
763static const struct dev_pm_ops ulite_pm_ops = {
764	SET_SYSTEM_SLEEP_PM_OPS(ulite_suspend, ulite_resume)
765	SET_RUNTIME_PM_OPS(ulite_runtime_suspend,
766			   ulite_runtime_resume, NULL)
767};
768
769#if defined(CONFIG_OF)
770/* Match table for of_platform binding */
771static const struct of_device_id ulite_of_match[] = {
772	{ .compatible = "xlnx,opb-uartlite-1.00.b", },
773	{ .compatible = "xlnx,xps-uartlite-1.00.a", },
774	{}
775};
776MODULE_DEVICE_TABLE(of, ulite_of_match);
 
 
777#endif /* CONFIG_OF */
778
779static int ulite_probe(struct platform_device *pdev)
780{
781	struct resource *res;
782	struct uartlite_data *pdata;
783	int irq, ret;
784	int id = pdev->id;
 
 
785
786	pdata = devm_kzalloc(&pdev->dev, sizeof(struct uartlite_data),
787			     GFP_KERNEL);
788	if (!pdata)
789		return -ENOMEM;
790
791	if (IS_ENABLED(CONFIG_OF)) {
792		const char *prop;
793		struct device_node *np = pdev->dev.of_node;
794		u32 val = 0;
795
796		prop = "port-number";
797		ret = of_property_read_u32(np, prop, &id);
798		if (ret && ret != -EINVAL)
799of_err:
800			return dev_err_probe(&pdev->dev, ret,
801					     "could not read %s\n", prop);
802
803		prop = "current-speed";
804		ret = of_property_read_u32(np, prop, &pdata->baud);
805		if (ret)
806			goto of_err;
807
808		prop = "xlnx,use-parity";
809		ret = of_property_read_u32(np, prop, &val);
810		if (ret && ret != -EINVAL)
811			goto of_err;
812
813		if (val) {
814			prop = "xlnx,odd-parity";
815			ret = of_property_read_u32(np, prop, &val);
816			if (ret)
817				goto of_err;
818
819			if (val)
820				pdata->cflags |= PARODD;
821			pdata->cflags |= PARENB;
822		}
823
824		val = 8;
825		prop = "xlnx,data-bits";
826		ret = of_property_read_u32(np, prop, &val);
827		if (ret && ret != -EINVAL)
828			goto of_err;
829
830		switch (val) {
831		case 5:
832			pdata->cflags |= CS5;
833			break;
834		case 6:
835			pdata->cflags |= CS6;
836			break;
837		case 7:
838			pdata->cflags |= CS7;
839			break;
840		case 8:
841			pdata->cflags |= CS8;
842			break;
843		default:
844			return dev_err_probe(&pdev->dev, -EINVAL,
845					     "bad data bits %d\n", val);
846		}
847	} else {
848		pdata->baud = 9600;
849		pdata->cflags = CS8;
850	}
851
852	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
853	if (!res)
854		return -ENODEV;
855
856	irq = platform_get_irq(pdev, 0);
857	if (irq < 0)
858		return irq;
859
860	pdata->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
861	if (IS_ERR(pdata->clk)) {
862		if (PTR_ERR(pdata->clk) != -ENOENT)
863			return PTR_ERR(pdata->clk);
864
865		/*
866		 * Clock framework support is optional, continue on
867		 * anyways if we don't find a matching clock.
868		 */
869		pdata->clk = NULL;
870	}
871
872	ret = clk_prepare_enable(pdata->clk);
873	if (ret) {
874		dev_err(&pdev->dev, "Failed to prepare clock\n");
875		return ret;
876	}
877
878	pm_runtime_use_autosuspend(&pdev->dev);
879	pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT);
880	pm_runtime_set_active(&pdev->dev);
881	pm_runtime_enable(&pdev->dev);
882
883	if (!ulite_uart_driver.state) {
884		dev_dbg(&pdev->dev, "uartlite: calling uart_register_driver()\n");
885		ret = uart_register_driver(&ulite_uart_driver);
886		if (ret < 0) {
887			dev_err(&pdev->dev, "Failed to register driver\n");
888			clk_disable_unprepare(pdata->clk);
889			return ret;
890		}
891	}
892
893	ret = ulite_assign(&pdev->dev, id, res->start, irq, pdata);
894
895	pm_runtime_mark_last_busy(&pdev->dev);
896	pm_runtime_put_autosuspend(&pdev->dev);
897
898	return ret;
899}
900
901static void ulite_remove(struct platform_device *pdev)
902{
903	struct uart_port *port = dev_get_drvdata(&pdev->dev);
904	struct uartlite_data *pdata = port->private_data;
905
906	clk_disable_unprepare(pdata->clk);
907	ulite_release(&pdev->dev);
908	pm_runtime_disable(&pdev->dev);
909	pm_runtime_set_suspended(&pdev->dev);
910	pm_runtime_dont_use_autosuspend(&pdev->dev);
911}
912
913/* work with hotplug and coldplug */
914MODULE_ALIAS("platform:uartlite");
915
916static struct platform_driver ulite_platform_driver = {
917	.probe = ulite_probe,
918	.remove = ulite_remove,
919	.driver = {
 
920		.name  = "uartlite",
921		.of_match_table = of_match_ptr(ulite_of_match),
922		.pm = &ulite_pm_ops,
923	},
924};
925
926/* ---------------------------------------------------------------------
927 * Module setup/teardown
928 */
929
930static int __init ulite_init(void)
931{
 
 
 
 
 
 
932
933	pr_debug("uartlite: calling platform_driver_register()\n");
934	return platform_driver_register(&ulite_platform_driver);
 
 
 
 
 
 
 
 
 
 
935}
936
937static void __exit ulite_exit(void)
938{
939	platform_driver_unregister(&ulite_platform_driver);
940	if (ulite_uart_driver.state)
941		uart_unregister_driver(&ulite_uart_driver);
942}
943
944module_init(ulite_init);
945module_exit(ulite_exit);
946
947MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
948MODULE_DESCRIPTION("Xilinx uartlite serial driver");
949MODULE_LICENSE("GPL");