xref: /openbmc/u-boot/drivers/serial/ns16550.c (revision ef64e782)
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 <common.h>
8 #include <clk.h>
9 #include <dm.h>
10 #include <errno.h>
11 #include <ns16550.h>
12 #include <reset.h>
13 #include <serial.h>
14 #include <watchdog.h>
15 #include <linux/types.h>
16 #include <asm/io.h>
17 
18 DECLARE_GLOBAL_DATA_PTR;
19 
20 #define UART_LCRVAL UART_LCR_8N1		/* 8 data, 1 stop, no parity */
21 #define UART_MCRVAL (UART_MCR_DTR | \
22 		     UART_MCR_RTS)		/* RTS/DTR */
23 
24 #ifndef CONFIG_DM_SERIAL
25 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
26 #define serial_out(x, y)	outb(x, (ulong)y)
27 #define serial_in(y)		inb((ulong)y)
28 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
29 #define serial_out(x, y)	out_be32(y, x)
30 #define serial_in(y)		in_be32(y)
31 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
32 #define serial_out(x, y)	out_le32(y, x)
33 #define serial_in(y)		in_le32(y)
34 #else
35 #define serial_out(x, y)	writeb(x, y)
36 #define serial_in(y)		readb(y)
37 #endif
38 #endif /* !CONFIG_DM_SERIAL */
39 
40 #if defined(CONFIG_SOC_KEYSTONE)
41 #define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE   0
42 #define UART_REG_VAL_PWREMU_MGMT_UART_ENABLE ((1 << 14) | (1 << 13) | (1 << 0))
43 #undef UART_MCRVAL
44 #ifdef CONFIG_SERIAL_HW_FLOW_CONTROL
45 #define UART_MCRVAL             (UART_MCR_RTS | UART_MCR_AFE)
46 #else
47 #define UART_MCRVAL             (UART_MCR_RTS)
48 #endif
49 #endif
50 
51 #ifndef CONFIG_SYS_NS16550_IER
52 #define CONFIG_SYS_NS16550_IER  0x00
53 #endif /* CONFIG_SYS_NS16550_IER */
54 
55 static inline void serial_out_shift(void *addr, int shift, int value)
56 {
57 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
58 	outb(value, (ulong)addr);
59 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_LITTLE_ENDIAN)
60 	out_le32(addr, value);
61 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
62 	out_be32(addr, value);
63 #elif defined(CONFIG_SYS_NS16550_MEM32)
64 	writel(value, addr);
65 #elif defined(CONFIG_SYS_BIG_ENDIAN)
66 	writeb(value, addr + (1 << shift) - 1);
67 #else
68 	writeb(value, addr);
69 #endif
70 }
71 
72 static inline int serial_in_shift(void *addr, int shift)
73 {
74 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
75 	return inb((ulong)addr);
76 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_LITTLE_ENDIAN)
77 	return in_le32(addr);
78 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
79 	return in_be32(addr);
80 #elif defined(CONFIG_SYS_NS16550_MEM32)
81 	return readl(addr);
82 #elif defined(CONFIG_SYS_BIG_ENDIAN)
83 	return readb(addr + (1 << shift) - 1);
84 #else
85 	return readb(addr);
86 #endif
87 }
88 
89 #ifdef CONFIG_DM_SERIAL
90 
91 #ifndef CONFIG_SYS_NS16550_CLK
92 #define CONFIG_SYS_NS16550_CLK  0
93 #endif
94 
95 static void ns16550_writeb(NS16550_t port, int offset, int value)
96 {
97 	struct ns16550_platdata *plat = port->plat;
98 	unsigned char *addr;
99 
100 	offset *= 1 << plat->reg_shift;
101 	addr = (unsigned char *)plat->base + offset;
102 
103 	/*
104 	 * As far as we know it doesn't make sense to support selection of
105 	 * these options at run-time, so use the existing CONFIG options.
106 	 */
107 	serial_out_shift(addr + plat->reg_offset, plat->reg_shift, value);
108 }
109 
110 static int ns16550_readb(NS16550_t port, int offset)
111 {
112 	struct ns16550_platdata *plat = port->plat;
113 	unsigned char *addr;
114 
115 	offset *= 1 << plat->reg_shift;
116 	addr = (unsigned char *)plat->base + offset;
117 
118 	return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
119 }
120 
121 static u32 ns16550_getfcr(NS16550_t port)
122 {
123 	struct ns16550_platdata *plat = port->plat;
124 
125 	return plat->fcr;
126 }
127 
128 /* We can clean these up once everything is moved to driver model */
129 #define serial_out(value, addr)	\
130 	ns16550_writeb(com_port, \
131 		(unsigned char *)addr - (unsigned char *)com_port, value)
132 #define serial_in(addr) \
133 	ns16550_readb(com_port, \
134 		(unsigned char *)addr - (unsigned char *)com_port)
135 #else
136 static u32 ns16550_getfcr(NS16550_t port)
137 {
138 	return UART_FCR_DEFVAL;
139 }
140 #endif
141 
142 int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
143 {
144 	const unsigned int mode_x_div = 16;
145 
146 	return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
147 }
148 
149 static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
150 {
151 	serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
152 	serial_out(baud_divisor & 0xff, &com_port->dll);
153 	serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
154 	serial_out(UART_LCRVAL, &com_port->lcr);
155 }
156 
157 void NS16550_init(NS16550_t com_port, int baud_divisor)
158 {
159 #if (defined(CONFIG_SPL_BUILD) && \
160 		(defined(CONFIG_OMAP34XX) || defined(CONFIG_OMAP44XX)))
161 	/*
162 	 * On some OMAP3/OMAP4 devices when UART3 is configured for boot mode
163 	 * before SPL starts only THRE bit is set. We have to empty the
164 	 * transmitter before initialization starts.
165 	 */
166 	if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
167 	     == UART_LSR_THRE) {
168 		if (baud_divisor != -1)
169 			NS16550_setbrg(com_port, baud_divisor);
170 		serial_out(0, &com_port->mdr1);
171 	}
172 #endif
173 
174 	while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
175 		;
176 
177 	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
178 #if defined(CONFIG_ARCH_OMAP2PLUS) || defined(CONFIG_OMAP_SERIAL)
179 	serial_out(0x7, &com_port->mdr1);	/* mode select reset TL16C750*/
180 #endif
181 
182 	serial_out(UART_MCRVAL, &com_port->mcr);
183 	serial_out(ns16550_getfcr(com_port), &com_port->fcr);
184 	if (baud_divisor != -1)
185 		NS16550_setbrg(com_port, baud_divisor);
186 #if defined(CONFIG_ARCH_OMAP2PLUS) || defined(CONFIG_SOC_DA8XX) || \
187 	defined(CONFIG_OMAP_SERIAL)
188 	/* /16 is proper to hit 115200 with 48MHz */
189 	serial_out(0, &com_port->mdr1);
190 #endif
191 #if defined(CONFIG_SOC_KEYSTONE)
192 	serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
193 #endif
194 }
195 
196 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
197 void NS16550_reinit(NS16550_t com_port, int baud_divisor)
198 {
199 	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
200 	NS16550_setbrg(com_port, 0);
201 	serial_out(UART_MCRVAL, &com_port->mcr);
202 	serial_out(ns16550_getfcr(com_port), &com_port->fcr);
203 	NS16550_setbrg(com_port, baud_divisor);
204 }
205 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
206 
207 void NS16550_putc(NS16550_t com_port, char c)
208 {
209 	while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
210 		;
211 	serial_out(c, &com_port->thr);
212 
213 	/*
214 	 * Call watchdog_reset() upon newline. This is done here in putc
215 	 * since the environment code uses a single puts() to print the complete
216 	 * environment upon "printenv". So we can't put this watchdog call
217 	 * in puts().
218 	 */
219 	if (c == '\n')
220 		WATCHDOG_RESET();
221 }
222 
223 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
224 char NS16550_getc(NS16550_t com_port)
225 {
226 	while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
227 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
228 		extern void usbtty_poll(void);
229 		usbtty_poll();
230 #endif
231 		WATCHDOG_RESET();
232 	}
233 	return serial_in(&com_port->rbr);
234 }
235 
236 int NS16550_tstc(NS16550_t com_port)
237 {
238 	return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
239 }
240 
241 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
242 
243 #ifdef CONFIG_DEBUG_UART_NS16550
244 
245 #include <debug_uart.h>
246 
247 static inline void _debug_uart_init(void)
248 {
249 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
250 	int baud_divisor;
251 
252 	/*
253 	 * We copy the code from above because it is already horribly messy.
254 	 * Trying to refactor to nicely remove the duplication doesn't seem
255 	 * feasible. The better fix is to move all users of this driver to
256 	 * driver model.
257 	 */
258 	baud_divisor = ns16550_calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
259 					    CONFIG_BAUDRATE);
260 	serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
261 	serial_dout(&com_port->mcr, UART_MCRVAL);
262 	serial_dout(&com_port->fcr, UART_FCR_DEFVAL);
263 
264 	serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
265 	serial_dout(&com_port->dll, baud_divisor & 0xff);
266 	serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
267 	serial_dout(&com_port->lcr, UART_LCRVAL);
268 }
269 
270 static inline void _debug_uart_putc(int ch)
271 {
272 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
273 
274 	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
275 		;
276 	serial_dout(&com_port->thr, ch);
277 }
278 
279 DEBUG_UART_FUNCS
280 
281 #endif
282 
283 #ifdef CONFIG_DM_SERIAL
284 static int ns16550_serial_putc(struct udevice *dev, const char ch)
285 {
286 	struct NS16550 *const com_port = dev_get_priv(dev);
287 
288 	if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
289 		return -EAGAIN;
290 	serial_out(ch, &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 (ch == '\n')
299 		WATCHDOG_RESET();
300 
301 	return 0;
302 }
303 
304 static int ns16550_serial_pending(struct udevice *dev, bool input)
305 {
306 	struct NS16550 *const com_port = dev_get_priv(dev);
307 
308 	if (input)
309 		return (serial_in(&com_port->lsr) & UART_LSR_DR) ? 1 : 0;
310 	else
311 		return (serial_in(&com_port->lsr) & UART_LSR_THRE) ? 0 : 1;
312 }
313 
314 static int ns16550_serial_getc(struct udevice *dev)
315 {
316 	struct NS16550 *const com_port = dev_get_priv(dev);
317 
318 	if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
319 		return -EAGAIN;
320 
321 	return serial_in(&com_port->rbr);
322 }
323 
324 static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
325 {
326 	struct NS16550 *const com_port = dev_get_priv(dev);
327 	struct ns16550_platdata *plat = com_port->plat;
328 	int clock_divisor;
329 
330 	clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
331 
332 	NS16550_setbrg(com_port, clock_divisor);
333 
334 	return 0;
335 }
336 
337 int ns16550_serial_probe(struct udevice *dev)
338 {
339 	struct NS16550 *const com_port = dev_get_priv(dev);
340 	struct reset_ctl_bulk reset_bulk;
341 	int ret;
342 
343 	ret = reset_get_bulk(dev, &reset_bulk);
344 	if (!ret)
345 		reset_deassert_bulk(&reset_bulk);
346 
347 	com_port->plat = dev_get_platdata(dev);
348 	NS16550_init(com_port, -1);
349 
350 	return 0;
351 }
352 
353 #if CONFIG_IS_ENABLED(OF_CONTROL)
354 enum {
355 	PORT_NS16550 = 0,
356 	PORT_JZ4780,
357 };
358 #endif
359 
360 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
361 int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
362 {
363 	struct ns16550_platdata *plat = dev->platdata;
364 	const u32 port_type = dev_get_driver_data(dev);
365 	fdt_addr_t addr;
366 	struct clk clk;
367 	int err;
368 
369 	/* try Processor Local Bus device first */
370 	addr = dev_read_addr(dev);
371 #if defined(CONFIG_PCI) && defined(CONFIG_DM_PCI)
372 	if (addr == FDT_ADDR_T_NONE) {
373 		/* then try pci device */
374 		struct fdt_pci_addr pci_addr;
375 		u32 bar;
376 		int ret;
377 
378 		/* we prefer to use a memory-mapped register */
379 		ret = fdtdec_get_pci_addr(gd->fdt_blob, dev_of_offset(dev),
380 					  FDT_PCI_SPACE_MEM32, "reg",
381 					  &pci_addr);
382 		if (ret) {
383 			/* try if there is any i/o-mapped register */
384 			ret = fdtdec_get_pci_addr(gd->fdt_blob,
385 						  dev_of_offset(dev),
386 						  FDT_PCI_SPACE_IO,
387 						  "reg", &pci_addr);
388 			if (ret)
389 				return ret;
390 		}
391 
392 		ret = fdtdec_get_pci_bar32(dev, &pci_addr, &bar);
393 		if (ret)
394 			return ret;
395 
396 		addr = bar;
397 	}
398 #endif
399 
400 	if (addr == FDT_ADDR_T_NONE)
401 		return -EINVAL;
402 
403 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
404 	plat->base = addr;
405 #else
406 	plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
407 #endif
408 
409 	plat->reg_offset = dev_read_u32_default(dev, "reg-offset", 0);
410 	plat->reg_shift = dev_read_u32_default(dev, "reg-shift", 0);
411 
412 	err = clk_get_by_index(dev, 0, &clk);
413 	if (!err) {
414 		err = clk_get_rate(&clk);
415 		if (!IS_ERR_VALUE(err))
416 			plat->clock = err;
417 	} else if (err != -ENOENT && err != -ENODEV && err != -ENOSYS) {
418 		debug("ns16550 failed to get clock\n");
419 		return err;
420 	}
421 
422 	if (!plat->clock)
423 		plat->clock = dev_read_u32_default(dev, "clock-frequency",
424 						   CONFIG_SYS_NS16550_CLK);
425 	if (!plat->clock) {
426 		debug("ns16550 clock not defined\n");
427 		return -EINVAL;
428 	}
429 
430 	plat->fcr = UART_FCR_DEFVAL;
431 	if (port_type == PORT_JZ4780)
432 		plat->fcr |= UART_FCR_UME;
433 
434 	return 0;
435 }
436 #endif
437 
438 const struct dm_serial_ops ns16550_serial_ops = {
439 	.putc = ns16550_serial_putc,
440 	.pending = ns16550_serial_pending,
441 	.getc = ns16550_serial_getc,
442 	.setbrg = ns16550_serial_setbrg,
443 };
444 
445 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
446 /*
447  * Please consider existing compatible strings before adding a new
448  * one to keep this table compact. Or you may add a generic "ns16550"
449  * compatible string to your dts.
450  */
451 static const struct udevice_id ns16550_serial_ids[] = {
452 	{ .compatible = "ns16550",		.data = PORT_NS16550 },
453 	{ .compatible = "ns16550a",		.data = PORT_NS16550 },
454 	{ .compatible = "ingenic,jz4780-uart",	.data = PORT_JZ4780  },
455 	{ .compatible = "nvidia,tegra20-uart",	.data = PORT_NS16550 },
456 	{ .compatible = "snps,dw-apb-uart",	.data = PORT_NS16550 },
457 	{}
458 };
459 #endif /* OF_CONTROL && !OF_PLATDATA */
460 
461 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
462 
463 /* TODO(sjg@chromium.org): Integrate this into a macro like CONFIG_IS_ENABLED */
464 #if !defined(CONFIG_TPL_BUILD) || defined(CONFIG_TPL_DM_SERIAL)
465 U_BOOT_DRIVER(ns16550_serial) = {
466 	.name	= "ns16550_serial",
467 	.id	= UCLASS_SERIAL,
468 #if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
469 	.of_match = ns16550_serial_ids,
470 	.ofdata_to_platdata = ns16550_serial_ofdata_to_platdata,
471 	.platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
472 #endif
473 	.priv_auto_alloc_size = sizeof(struct NS16550),
474 	.probe = ns16550_serial_probe,
475 	.ops	= &ns16550_serial_ops,
476 	.flags	= DM_FLAG_PRE_RELOC,
477 };
478 #endif
479 #endif /* SERIAL_PRESENT */
480 
481 #endif /* CONFIG_DM_SERIAL */
482