1 /*
2  * COM1 NS16550 support
3  * originally from linux source (arch/powerpc/boot/ns16550.c)
4  * modified to use CONFIG_SYS_ISA_MEM and new defines
5  */
6 
7 #include <clock_legacy.h>
8 #include <common.h>
9 #include <clk.h>
10 #include <dm.h>
11 #include <errno.h>
12 #include <log.h>
13 #include <ns16550.h>
14 #include <reset.h>
15 #include <serial.h>
16 #include <watchdog.h>
17 #include <asm/global_data.h>
18 #include <linux/err.h>
19 #include <linux/types.h>
20 #include <asm/io.h>
21 
22 DECLARE_GLOBAL_DATA_PTR;
23 
24 #define UART_LCRVAL UART_LCR_8N1		/* 8 data, 1 stop, no parity */
25 #define UART_MCRVAL (UART_MCR_DTR | \
26 		     UART_MCR_RTS)		/* RTS/DTR */
27 
28 #if !CONFIG_IS_ENABLED(DM_SERIAL)
29 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
30 #define serial_out(x, y)	outb(x, (ulong)y)
31 #define serial_in(y)		inb((ulong)y)
32 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
33 #define serial_out(x, y)	out_be32(y, x)
34 #define serial_in(y)		in_be32(y)
35 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
36 #define serial_out(x, y)	out_le32(y, x)
37 #define serial_in(y)		in_le32(y)
38 #else
39 #define serial_out(x, y)	writeb(x, y)
40 #define serial_in(y)		readb(y)
41 #endif
42 #endif /* !CONFIG_DM_SERIAL */
43 
44 #if defined(CONFIG_ARCH_KEYSTONE)
45 #define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE   0
46 #define UART_REG_VAL_PWREMU_MGMT_UART_ENABLE ((1 << 14) | (1 << 13) | (1 << 0))
47 #undef UART_MCRVAL
48 #ifdef CONFIG_SERIAL_HW_FLOW_CONTROL
49 #define UART_MCRVAL             (UART_MCR_RTS | UART_MCR_AFE)
50 #else
51 #define UART_MCRVAL             (UART_MCR_RTS)
52 #endif
53 #endif
54 
55 #ifndef CFG_SYS_NS16550_IER
56 #define CFG_SYS_NS16550_IER  0x00
57 #endif /* CFG_SYS_NS16550_IER */
58 
serial_out_shift(void * addr,int shift,int value)59 static inline void serial_out_shift(void *addr, int shift, int value)
60 {
61 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
62 	outb(value, (ulong)addr);
63 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_LITTLE_ENDIAN)
64 	out_le32(addr, value);
65 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
66 	out_be32(addr, value);
67 #elif defined(CONFIG_SYS_NS16550_MEM32)
68 	writel(value, addr);
69 #elif defined(CONFIG_SYS_BIG_ENDIAN)
70 	writeb(value, addr + (1 << shift) - 1);
71 #else
72 	writeb(value, addr);
73 #endif
74 }
75 
serial_in_shift(void * addr,int shift)76 static inline int serial_in_shift(void *addr, int shift)
77 {
78 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
79 	return inb((ulong)addr);
80 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_LITTLE_ENDIAN)
81 	return in_le32(addr);
82 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
83 	return in_be32(addr);
84 #elif defined(CONFIG_SYS_NS16550_MEM32)
85 	return readl(addr);
86 #elif defined(CONFIG_SYS_BIG_ENDIAN)
87 	return readb(addr + (1 << shift) - 1);
88 #else
89 	return readb(addr);
90 #endif
91 }
92 
93 #if CONFIG_IS_ENABLED(DM_SERIAL)
94 
95 #ifndef CFG_SYS_NS16550_CLK
96 #define CFG_SYS_NS16550_CLK  0
97 #endif
98 
99 /*
100  * Use this #ifdef for now since many platforms don't define in(), out(),
101  * out_le32(), etc. but we don't have #defines to indicate this.
102  *
103  * TODO(sjg@chromium.org): Add CONFIG options to indicate what I/O is available
104  * on a platform
105  */
106 #ifdef CONFIG_NS16550_DYNAMIC
serial_out_dynamic(struct ns16550_plat * plat,u8 * addr,int value)107 static void serial_out_dynamic(struct ns16550_plat *plat, u8 *addr,
108 			       int value)
109 {
110 	if (plat->flags & NS16550_FLAG_IO) {
111 		outb(value, addr);
112 	} else if (plat->reg_width == 4) {
113 		if (plat->flags & NS16550_FLAG_ENDIAN) {
114 			if (plat->flags & NS16550_FLAG_BE)
115 				out_be32(addr, value);
116 			else
117 				out_le32(addr, value);
118 		} else {
119 			writel(value, addr);
120 		}
121 	} else if (plat->flags & NS16550_FLAG_BE) {
122 		writeb(value, addr + (1 << plat->reg_shift) - 1);
123 	} else {
124 		writeb(value, addr);
125 	}
126 }
127 
serial_in_dynamic(struct ns16550_plat * plat,u8 * addr)128 static int serial_in_dynamic(struct ns16550_plat *plat, u8 *addr)
129 {
130 	if (plat->flags & NS16550_FLAG_IO) {
131 		return inb(addr);
132 	} else if (plat->reg_width == 4) {
133 		if (plat->flags & NS16550_FLAG_ENDIAN) {
134 			if (plat->flags & NS16550_FLAG_BE)
135 				return in_be32(addr);
136 			else
137 				return in_le32(addr);
138 		} else {
139 			return readl(addr);
140 		}
141 	} else if (plat->flags & NS16550_FLAG_BE) {
142 		return readb(addr + (1 << plat->reg_shift) - 1);
143 	} else {
144 		return readb(addr);
145 	}
146 }
147 #else
serial_out_dynamic(struct ns16550_plat * plat,u8 * addr,int value)148 static inline void serial_out_dynamic(struct ns16550_plat *plat, u8 *addr,
149 				      int value)
150 {
151 }
152 
serial_in_dynamic(struct ns16550_plat * plat,u8 * addr)153 static inline int serial_in_dynamic(struct ns16550_plat *plat, u8 *addr)
154 {
155 	return 0;
156 }
157 
158 #endif /* CONFIG_NS16550_DYNAMIC */
159 
ns16550_writeb(struct ns16550 * port,int offset,int value)160 static void ns16550_writeb(struct ns16550 *port, int offset, int value)
161 {
162 	struct ns16550_plat *plat = port->plat;
163 	unsigned char *addr;
164 
165 	offset *= 1 << plat->reg_shift;
166 	addr = (unsigned char *)plat->base + offset + plat->reg_offset;
167 
168 	if (IS_ENABLED(CONFIG_NS16550_DYNAMIC))
169 		serial_out_dynamic(plat, addr, value);
170 	else
171 		serial_out_shift(addr, plat->reg_shift, value);
172 }
173 
ns16550_readb(struct ns16550 * port,int offset)174 static int ns16550_readb(struct ns16550 *port, int offset)
175 {
176 	struct ns16550_plat *plat = port->plat;
177 	unsigned char *addr;
178 
179 	offset *= 1 << plat->reg_shift;
180 	addr = (unsigned char *)plat->base + offset + plat->reg_offset;
181 
182 	if (IS_ENABLED(CONFIG_NS16550_DYNAMIC))
183 		return serial_in_dynamic(plat, addr);
184 	else
185 		return serial_in_shift(addr, plat->reg_shift);
186 }
187 
ns16550_getfcr(struct ns16550 * port)188 static u32 ns16550_getfcr(struct ns16550 *port)
189 {
190 	struct ns16550_plat *plat = port->plat;
191 
192 	return plat->fcr;
193 }
194 
195 /* We can clean these up once everything is moved to driver model */
196 #define serial_out(value, addr)	\
197 	ns16550_writeb(com_port, \
198 		(unsigned char *)addr - (unsigned char *)com_port, value)
199 #define serial_in(addr) \
200 	ns16550_readb(com_port, \
201 		(unsigned char *)addr - (unsigned char *)com_port)
202 #else
ns16550_getfcr(struct ns16550 * port)203 static u32 ns16550_getfcr(struct ns16550 *port)
204 {
205 	return UART_FCR_DEFVAL;
206 }
207 #endif
208 
ns16550_calc_divisor(struct ns16550 * port,int clock,int baudrate)209 int ns16550_calc_divisor(struct ns16550 *port, int clock, int baudrate)
210 {
211 	const unsigned int mode_x_div = 16;
212 
213 	return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
214 }
215 
ns16550_setbrg(struct ns16550 * com_port,int baud_divisor)216 static void ns16550_setbrg(struct ns16550 *com_port, int baud_divisor)
217 {
218 	/* to keep serial format, read lcr before writing BKSE */
219 	int lcr_val = serial_in(&com_port->lcr) & ~UART_LCR_BKSE;
220 
221 	serial_out(UART_LCR_BKSE | lcr_val, &com_port->lcr);
222 	serial_out(baud_divisor & 0xff, &com_port->dll);
223 	serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
224 	serial_out(lcr_val, &com_port->lcr);
225 }
226 
ns16550_init(struct ns16550 * com_port,int baud_divisor)227 void ns16550_init(struct ns16550 *com_port, int baud_divisor)
228 {
229 #if (defined(CONFIG_SPL_BUILD) && \
230 		(defined(CONFIG_OMAP34XX) || defined(CONFIG_OMAP44XX)))
231 	/*
232 	 * On some OMAP3/OMAP4 devices when UART3 is configured for boot mode
233 	 * before SPL starts only THRE bit is set. We have to empty the
234 	 * transmitter before initialization starts.
235 	 */
236 	if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
237 	     == UART_LSR_THRE) {
238 		if (baud_divisor != -1)
239 			ns16550_setbrg(com_port, baud_divisor);
240 		else {
241 			// Re-use old baud rate divisor to flush transmit reg.
242 			const int dll = serial_in(&com_port->dll);
243 			const int dlm = serial_in(&com_port->dlm);
244 			const int divisor = dll | (dlm << 8);
245 			ns16550_setbrg(com_port, divisor);
246 		}
247 		serial_out(0, &com_port->mdr1);
248 	}
249 #endif
250 
251 	while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
252 		;
253 
254 	serial_out(CFG_SYS_NS16550_IER, &com_port->ier);
255 #if defined(CONFIG_ARCH_OMAP2PLUS) || defined(CONFIG_OMAP_SERIAL)
256 	serial_out(0x7, &com_port->mdr1);	/* mode select reset TL16C750*/
257 #endif
258 
259 	serial_out(UART_MCRVAL, &com_port->mcr);
260 	serial_out(ns16550_getfcr(com_port), &com_port->fcr);
261 	/* initialize serial config to 8N1 before writing baudrate */
262 	serial_out(UART_LCRVAL, &com_port->lcr);
263 	if (baud_divisor != -1)
264 		ns16550_setbrg(com_port, baud_divisor);
265 #if defined(CONFIG_ARCH_OMAP2PLUS) || defined(CONFIG_SOC_DA8XX) || \
266 	defined(CONFIG_OMAP_SERIAL)
267 	/* /16 is proper to hit 115200 with 48MHz */
268 	serial_out(0, &com_port->mdr1);
269 #endif
270 #if defined(CONFIG_ARCH_KEYSTONE)
271 	serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
272 #endif
273 }
274 
275 #if !CONFIG_IS_ENABLED(NS16550_MIN_FUNCTIONS)
ns16550_reinit(struct ns16550 * com_port,int baud_divisor)276 void ns16550_reinit(struct ns16550 *com_port, int baud_divisor)
277 {
278 	serial_out(CFG_SYS_NS16550_IER, &com_port->ier);
279 	ns16550_setbrg(com_port, 0);
280 	serial_out(UART_MCRVAL, &com_port->mcr);
281 	serial_out(ns16550_getfcr(com_port), &com_port->fcr);
282 	ns16550_setbrg(com_port, baud_divisor);
283 }
284 #endif /* !CONFIG_IS_ENABLED(NS16550_MIN_FUNCTIONS) */
285 
ns16550_putc(struct ns16550 * com_port,char c)286 void ns16550_putc(struct ns16550 *com_port, char c)
287 {
288 	while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
289 		;
290 	serial_out(c, &com_port->thr);
291 
292 	/*
293 	 * Call watchdog_reset() upon newline. This is done here in putc
294 	 * since the environment code uses a single puts() to print the complete
295 	 * environment upon "printenv". So we can't put this watchdog call
296 	 * in puts().
297 	 */
298 	if (c == '\n')
299 		schedule();
300 }
301 
302 #if !CONFIG_IS_ENABLED(NS16550_MIN_FUNCTIONS)
ns16550_getc(struct ns16550 * com_port)303 char ns16550_getc(struct ns16550 *com_port)
304 {
305 	while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
306 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
307 		extern void usbtty_poll(void);
308 		usbtty_poll();
309 #endif
310 		schedule();
311 	}
312 	return serial_in(&com_port->rbr);
313 }
314 
ns16550_tstc(struct ns16550 * com_port)315 int ns16550_tstc(struct ns16550 *com_port)
316 {
317 	return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
318 }
319 
320 #endif /* !CONFIG_IS_ENABLED(NS16550_MIN_FUNCTIONS) */
321 
322 #ifdef CONFIG_DEBUG_UART_NS16550
323 
324 #include <debug_uart.h>
325 
_debug_uart_init(void)326 static inline void _debug_uart_init(void)
327 {
328 	struct ns16550 *com_port = (struct ns16550 *)CONFIG_VAL(DEBUG_UART_BASE);
329 	int baud_divisor;
330 
331 	/* Wait until tx buffer is empty */
332 	while (!(serial_din(&com_port->lsr) & UART_LSR_TEMT))
333 		;
334 
335 	/*
336 	 * We copy the code from above because it is already horribly messy.
337 	 * Trying to refactor to nicely remove the duplication doesn't seem
338 	 * feasible. The better fix is to move all users of this driver to
339 	 * driver model.
340 	 */
341 	baud_divisor = ns16550_calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
342 					    CONFIG_BAUDRATE);
343 	serial_dout(&com_port->ier, CFG_SYS_NS16550_IER);
344 	serial_dout(&com_port->mcr, UART_MCRVAL);
345 	serial_dout(&com_port->fcr, UART_FCR_DEFVAL);
346 
347 	serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
348 	serial_dout(&com_port->dll, baud_divisor & 0xff);
349 	serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
350 	serial_dout(&com_port->lcr, UART_LCRVAL);
351 }
352 
NS16550_read_baud_divisor(struct ns16550 * com_port)353 static inline int NS16550_read_baud_divisor(struct ns16550 *com_port)
354 {
355 	int ret;
356 
357 	serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
358 	ret = serial_din(&com_port->dll) & 0xff;
359 	ret |= (serial_din(&com_port->dlm) & 0xff) << 8;
360 	serial_dout(&com_port->lcr, UART_LCRVAL);
361 
362 	return ret;
363 }
364 
_debug_uart_putc(int ch)365 static inline void _debug_uart_putc(int ch)
366 {
367 	struct ns16550 *com_port = (struct ns16550 *)CONFIG_VAL(DEBUG_UART_BASE);
368 
369 	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE)) {
370 #ifdef CONFIG_DEBUG_UART_NS16550_CHECK_ENABLED
371 		if (!NS16550_read_baud_divisor(com_port))
372 			return;
373 #endif
374 	}
375 	serial_dout(&com_port->thr, ch);
376 }
377 
378 DEBUG_UART_FUNCS
379 
380 #endif
381 
382 #if CONFIG_IS_ENABLED(DM_SERIAL)
ns16550_serial_putc(struct udevice * dev,const char ch)383 static int ns16550_serial_putc(struct udevice *dev, const char ch)
384 {
385 	struct ns16550 *const com_port = dev_get_priv(dev);
386 
387 	if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
388 		return -EAGAIN;
389 	serial_out(ch, &com_port->thr);
390 
391 	/*
392 	 * Call watchdog_reset() upon newline. This is done here in putc
393 	 * since the environment code uses a single puts() to print the complete
394 	 * environment upon "printenv". So we can't put this watchdog call
395 	 * in puts().
396 	 */
397 	if (ch == '\n')
398 		schedule();
399 
400 	return 0;
401 }
402 
ns16550_serial_pending(struct udevice * dev,bool input)403 static int ns16550_serial_pending(struct udevice *dev, bool input)
404 {
405 	struct ns16550 *const com_port = dev_get_priv(dev);
406 
407 	if (input)
408 		return (serial_in(&com_port->lsr) & UART_LSR_DR) ? 1 : 0;
409 	else
410 		return (serial_in(&com_port->lsr) & UART_LSR_THRE) ? 0 : 1;
411 }
412 
ns16550_serial_getc(struct udevice * dev)413 static int ns16550_serial_getc(struct udevice *dev)
414 {
415 	struct ns16550 *const com_port = dev_get_priv(dev);
416 
417 	if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
418 		return -EAGAIN;
419 
420 	return serial_in(&com_port->rbr);
421 }
422 
ns16550_serial_setbrg(struct udevice * dev,int baudrate)423 static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
424 {
425 	struct ns16550 *const com_port = dev_get_priv(dev);
426 	struct ns16550_plat *plat = com_port->plat;
427 	int clock_divisor;
428 
429 	clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
430 
431 	ns16550_setbrg(com_port, clock_divisor);
432 
433 	return 0;
434 }
435 
ns16550_serial_setconfig(struct udevice * dev,uint serial_config)436 static int ns16550_serial_setconfig(struct udevice *dev, uint serial_config)
437 {
438 	struct ns16550 *const com_port = dev_get_priv(dev);
439 	int lcr_val = UART_LCR_WLS_8;
440 	uint parity = SERIAL_GET_PARITY(serial_config);
441 	uint bits = SERIAL_GET_BITS(serial_config);
442 	uint stop = SERIAL_GET_STOP(serial_config);
443 
444 	/*
445 	 * only parity config is implemented, check if other serial settings
446 	 * are the default one.
447 	 */
448 	if (bits != SERIAL_8_BITS || stop != SERIAL_ONE_STOP)
449 		return -ENOTSUPP; /* not supported in driver*/
450 
451 	switch (parity) {
452 	case SERIAL_PAR_NONE:
453 		/* no bits to add */
454 		break;
455 	case SERIAL_PAR_ODD:
456 		lcr_val |= UART_LCR_PEN;
457 		break;
458 	case SERIAL_PAR_EVEN:
459 		lcr_val |= UART_LCR_PEN | UART_LCR_EPS;
460 		break;
461 	default:
462 		return -ENOTSUPP; /* not supported in driver*/
463 	}
464 
465 	serial_out(lcr_val, &com_port->lcr);
466 	return 0;
467 }
468 
ns16550_serial_getinfo(struct udevice * dev,struct serial_device_info * info)469 static int ns16550_serial_getinfo(struct udevice *dev,
470 				  struct serial_device_info *info)
471 {
472 	struct ns16550 *const com_port = dev_get_priv(dev);
473 	struct ns16550_plat *plat = com_port->plat;
474 
475 	info->type = SERIAL_CHIP_16550_COMPATIBLE;
476 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
477 	info->addr_space = SERIAL_ADDRESS_SPACE_IO;
478 #else
479 	info->addr_space = SERIAL_ADDRESS_SPACE_MEMORY;
480 #endif
481 	info->addr = plat->base;
482 	info->reg_width = plat->reg_width;
483 	info->reg_shift = plat->reg_shift;
484 	info->reg_offset = plat->reg_offset;
485 	info->clock = plat->clock;
486 
487 	return 0;
488 }
489 
ns16550_serial_assign_base(struct ns16550_plat * plat,fdt_addr_t base)490 static int ns16550_serial_assign_base(struct ns16550_plat *plat, fdt_addr_t base)
491 {
492 	if (base == FDT_ADDR_T_NONE)
493 		return -EINVAL;
494 
495 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
496 	plat->base = base;
497 #else
498 	plat->base = (unsigned long)map_physmem(base, 0, MAP_NOCACHE);
499 #endif
500 
501 	return 0;
502 }
503 
ns16550_serial_probe(struct udevice * dev)504 int ns16550_serial_probe(struct udevice *dev)
505 {
506 	struct ns16550_plat *plat = dev_get_plat(dev);
507 	struct ns16550 *const com_port = dev_get_priv(dev);
508 	struct reset_ctl_bulk reset_bulk;
509 	fdt_addr_t addr;
510 	int ret;
511 
512 	/*
513 	 * If we are on PCI bus, either directly attached to a PCI root port,
514 	 * or via a PCI bridge, assign plat->base before probing hardware.
515 	 */
516 	if (device_is_on_pci_bus(dev)) {
517 		addr = devfdt_get_addr_pci(dev);
518 		ret = ns16550_serial_assign_base(plat, addr);
519 		if (ret)
520 			return ret;
521 	}
522 
523 	ret = reset_get_bulk(dev, &reset_bulk);
524 	if (!ret)
525 		reset_deassert_bulk(&reset_bulk);
526 
527 	com_port->plat = dev_get_plat(dev);
528 	ns16550_init(com_port, -1);
529 
530 	return 0;
531 }
532 
533 #if CONFIG_IS_ENABLED(OF_CONTROL)
534 enum {
535 	PORT_NS16550 = 0,
536 	PORT_JZ4780,
537 };
538 #endif
539 
540 #if CONFIG_IS_ENABLED(OF_REAL)
ns16550_serial_of_to_plat(struct udevice * dev)541 int ns16550_serial_of_to_plat(struct udevice *dev)
542 {
543 	struct ns16550_plat *plat = dev_get_plat(dev);
544 	const u32 port_type = dev_get_driver_data(dev);
545 	fdt_addr_t addr;
546 	struct clk clk;
547 	int err;
548 
549 	addr = dev_read_addr(dev);
550 	err = ns16550_serial_assign_base(plat, addr);
551 	if (err && !device_is_on_pci_bus(dev))
552 		return err;
553 
554 	plat->reg_offset = dev_read_u32_default(dev, "reg-offset", 0);
555 	plat->reg_shift = dev_read_u32_default(dev, "reg-shift", 0);
556 	plat->reg_width = dev_read_u32_default(dev, "reg-io-width", 1);
557 
558 	err = clk_get_by_index(dev, 0, &clk);
559 	if (!err) {
560 		err = clk_get_rate(&clk);
561 		if (!IS_ERR_VALUE(err))
562 			plat->clock = err;
563 	} else if (err != -ENOENT && err != -ENODEV && err != -ENOSYS) {
564 		debug("ns16550 failed to get clock\n");
565 		return err;
566 	}
567 
568 	if (!plat->clock)
569 		plat->clock = dev_read_u32_default(dev, "clock-frequency",
570 						   CFG_SYS_NS16550_CLK);
571 	if (!plat->clock)
572 		plat->clock = CFG_SYS_NS16550_CLK;
573 	if (!plat->clock) {
574 		debug("ns16550 clock not defined\n");
575 		return -EINVAL;
576 	}
577 
578 	plat->fcr = UART_FCR_DEFVAL;
579 	if (port_type == PORT_JZ4780)
580 		plat->fcr |= UART_FCR_UME;
581 
582 	return 0;
583 }
584 #endif
585 
586 const struct dm_serial_ops ns16550_serial_ops = {
587 	.putc = ns16550_serial_putc,
588 	.pending = ns16550_serial_pending,
589 	.getc = ns16550_serial_getc,
590 	.setbrg = ns16550_serial_setbrg,
591 	.setconfig = ns16550_serial_setconfig,
592 	.getinfo = ns16550_serial_getinfo,
593 };
594 
595 #if CONFIG_IS_ENABLED(OF_REAL)
596 /*
597  * Please consider existing compatible strings before adding a new
598  * one to keep this table compact. Or you may add a generic "ns16550"
599  * compatible string to your dts.
600  */
601 static const struct udevice_id ns16550_serial_ids[] = {
602 	{ .compatible = "ns16550",		.data = PORT_NS16550 },
603 	{ .compatible = "ns16550a",		.data = PORT_NS16550 },
604 	{ .compatible = "ingenic,jz4780-uart",	.data = PORT_JZ4780  },
605 	{ .compatible = "nvidia,tegra20-uart",	.data = PORT_NS16550 },
606 	{ .compatible = "snps,dw-apb-uart",	.data = PORT_NS16550 },
607 	{}
608 };
609 #endif /* OF_REAL */
610 
611 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
612 
613 /* TODO(sjg@chromium.org): Integrate this into a macro like CONFIG_IS_ENABLED */
614 #if !defined(CONFIG_TPL_BUILD) || defined(CONFIG_TPL_DM_SERIAL)
615 U_BOOT_DRIVER(ns16550_serial) = {
616 	.name	= "ns16550_serial",
617 	.id	= UCLASS_SERIAL,
618 #if CONFIG_IS_ENABLED(OF_REAL)
619 	.of_match = ns16550_serial_ids,
620 	.of_to_plat = ns16550_serial_of_to_plat,
621 	.plat_auto	= sizeof(struct ns16550_plat),
622 #endif
623 	.priv_auto	= sizeof(struct ns16550),
624 	.probe = ns16550_serial_probe,
625 	.ops	= &ns16550_serial_ops,
626 #if !CONFIG_IS_ENABLED(OF_CONTROL)
627 	.flags	= DM_FLAG_PRE_RELOC,
628 #endif
629 };
630 
631 DM_DRIVER_ALIAS(ns16550_serial, ti_da830_uart)
632 #endif
633 #endif /* SERIAL_PRESENT */
634 
635 #endif /* CONFIG_DM_SERIAL */
636