xref: /openbmc/u-boot/drivers/serial/ns16550.c (revision 4349b55b)
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 <dm.h>
9 #include <errno.h>
10 #include <fdtdec.h>
11 #include <ns16550.h>
12 #include <serial.h>
13 #include <watchdog.h>
14 #include <linux/types.h>
15 #include <asm/io.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 #define UART_LCRVAL UART_LCR_8N1		/* 8 data, 1 stop, no parity */
20 #define UART_MCRVAL (UART_MCR_DTR | \
21 		     UART_MCR_RTS)		/* RTS/DTR */
22 #define UART_FCRVAL (UART_FCR_FIFO_EN |	\
23 		     UART_FCR_RXSR |	\
24 		     UART_FCR_TXSR)		/* Clear & enable FIFOs */
25 
26 #ifndef CONFIG_DM_SERIAL
27 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
28 #define serial_out(x, y)	outb(x, (ulong)y)
29 #define serial_in(y)		inb((ulong)y)
30 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
31 #define serial_out(x, y)	out_be32(y, x)
32 #define serial_in(y)		in_be32(y)
33 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
34 #define serial_out(x, y)	out_le32(y, x)
35 #define serial_in(y)		in_le32(y)
36 #else
37 #define serial_out(x, y)	writeb(x, y)
38 #define serial_in(y)		readb(y)
39 #endif
40 #endif /* !CONFIG_DM_SERIAL */
41 
42 #if defined(CONFIG_SOC_KEYSTONE)
43 #define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE   0
44 #define UART_REG_VAL_PWREMU_MGMT_UART_ENABLE ((1 << 14) | (1 << 13) | (1 << 0))
45 #undef UART_MCRVAL
46 #ifdef CONFIG_SERIAL_HW_FLOW_CONTROL
47 #define UART_MCRVAL             (UART_MCR_RTS | UART_MCR_AFE)
48 #else
49 #define UART_MCRVAL             (UART_MCR_RTS)
50 #endif
51 #endif
52 
53 #ifndef CONFIG_SYS_NS16550_IER
54 #define CONFIG_SYS_NS16550_IER  0x00
55 #endif /* CONFIG_SYS_NS16550_IER */
56 
57 #ifdef CONFIG_DM_SERIAL
58 
59 #ifndef CONFIG_SYS_NS16550_CLK
60 #define CONFIG_SYS_NS16550_CLK  0
61 #endif
62 
63 static inline void serial_out_shift(void *addr, int shift, int value)
64 {
65 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
66 	outb(value, (ulong)addr);
67 #elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
68 	out_le32(addr, value);
69 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
70 	out_be32(addr, value);
71 #elif defined(CONFIG_SYS_NS16550_MEM32)
72 	writel(value, addr);
73 #elif defined(CONFIG_SYS_BIG_ENDIAN)
74 	writeb(value, addr + (1 << shift) - 1);
75 #else
76 	writeb(value, addr);
77 #endif
78 }
79 
80 static inline int serial_in_shift(void *addr, int shift)
81 {
82 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
83 	return inb((ulong)addr);
84 #elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
85 	return in_le32(addr);
86 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
87 	return in_be32(addr);
88 #elif defined(CONFIG_SYS_NS16550_MEM32)
89 	return readl(addr);
90 #elif defined(CONFIG_SYS_BIG_ENDIAN)
91 	return readb(addr + (1 << shift) - 1);
92 #else
93 	return readb(addr);
94 #endif
95 }
96 
97 static void ns16550_writeb(NS16550_t port, int offset, int value)
98 {
99 	struct ns16550_platdata *plat = port->plat;
100 	unsigned char *addr;
101 
102 	offset *= 1 << plat->reg_shift;
103 	addr = (unsigned char *)plat->base + offset;
104 
105 	/*
106 	 * As far as we know it doesn't make sense to support selection of
107 	 * these options at run-time, so use the existing CONFIG options.
108 	 */
109 	serial_out_shift(addr + plat->reg_offset, plat->reg_shift, value);
110 }
111 
112 static int ns16550_readb(NS16550_t port, int offset)
113 {
114 	struct ns16550_platdata *plat = port->plat;
115 	unsigned char *addr;
116 
117 	offset *= 1 << plat->reg_shift;
118 	addr = (unsigned char *)plat->base + offset;
119 
120 	return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
121 }
122 
123 /* We can clean these up once everything is moved to driver model */
124 #define serial_out(value, addr)	\
125 	ns16550_writeb(com_port, \
126 		(unsigned char *)addr - (unsigned char *)com_port, value)
127 #define serial_in(addr) \
128 	ns16550_readb(com_port, \
129 		(unsigned char *)addr - (unsigned char *)com_port)
130 #endif
131 
132 static inline int calc_divisor(NS16550_t port, int clock, int baudrate)
133 {
134 	const unsigned int mode_x_div = 16;
135 
136 	return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
137 }
138 
139 int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
140 {
141 #ifdef CONFIG_OMAP1510
142 	/* If can't cleanly clock 115200 set div to 1 */
143 	if ((clock == 12000000) && (baudrate == 115200)) {
144 		port->osc_12m_sel = OSC_12M_SEL;  /* enable 6.5 * divisor */
145 		return 1;			/* return 1 for base divisor */
146 	}
147 	port->osc_12m_sel = 0;			/* clear if previsouly set */
148 #endif
149 
150 	return calc_divisor(port, clock, baudrate);
151 }
152 
153 static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
154 {
155 	serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
156 	serial_out(baud_divisor & 0xff, &com_port->dll);
157 	serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
158 	serial_out(UART_LCRVAL, &com_port->lcr);
159 }
160 
161 void NS16550_init(NS16550_t com_port, int baud_divisor)
162 {
163 #if (defined(CONFIG_SPL_BUILD) && \
164 		(defined(CONFIG_OMAP34XX) || defined(CONFIG_OMAP44XX)))
165 	/*
166 	 * On some OMAP3/OMAP4 devices when UART3 is configured for boot mode
167 	 * before SPL starts only THRE bit is set. We have to empty the
168 	 * transmitter before initialization starts.
169 	 */
170 	if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
171 	     == UART_LSR_THRE) {
172 		if (baud_divisor != -1)
173 			NS16550_setbrg(com_port, baud_divisor);
174 		serial_out(0, &com_port->mdr1);
175 	}
176 #endif
177 
178 	while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
179 		;
180 
181 	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
182 #if defined(CONFIG_OMAP) || defined(CONFIG_AM33XX) || \
183 			defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
184 	serial_out(0x7, &com_port->mdr1);	/* mode select reset TL16C750*/
185 #endif
186 	serial_out(UART_MCRVAL, &com_port->mcr);
187 	serial_out(UART_FCRVAL, &com_port->fcr);
188 	if (baud_divisor != -1)
189 		NS16550_setbrg(com_port, baud_divisor);
190 #if defined(CONFIG_OMAP) || \
191 	defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \
192 	defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
193 
194 	/* /16 is proper to hit 115200 with 48MHz */
195 	serial_out(0, &com_port->mdr1);
196 #endif /* CONFIG_OMAP */
197 #if defined(CONFIG_SOC_KEYSTONE)
198 	serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
199 #endif
200 }
201 
202 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
203 void NS16550_reinit(NS16550_t com_port, int baud_divisor)
204 {
205 	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
206 	NS16550_setbrg(com_port, 0);
207 	serial_out(UART_MCRVAL, &com_port->mcr);
208 	serial_out(UART_FCRVAL, &com_port->fcr);
209 	NS16550_setbrg(com_port, baud_divisor);
210 }
211 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
212 
213 void NS16550_putc(NS16550_t com_port, char c)
214 {
215 	while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
216 		;
217 	serial_out(c, &com_port->thr);
218 
219 	/*
220 	 * Call watchdog_reset() upon newline. This is done here in putc
221 	 * since the environment code uses a single puts() to print the complete
222 	 * environment upon "printenv". So we can't put this watchdog call
223 	 * in puts().
224 	 */
225 	if (c == '\n')
226 		WATCHDOG_RESET();
227 }
228 
229 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
230 char NS16550_getc(NS16550_t com_port)
231 {
232 	while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
233 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
234 		extern void usbtty_poll(void);
235 		usbtty_poll();
236 #endif
237 		WATCHDOG_RESET();
238 	}
239 	return serial_in(&com_port->rbr);
240 }
241 
242 int NS16550_tstc(NS16550_t com_port)
243 {
244 	return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
245 }
246 
247 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
248 
249 #ifdef CONFIG_DEBUG_UART_NS16550
250 
251 #include <debug_uart.h>
252 
253 #define serial_dout(reg, value)	\
254 	serial_out_shift((char *)com_port + \
255 		((char *)reg - (char *)com_port) * \
256 			(1 << CONFIG_DEBUG_UART_SHIFT), \
257 		CONFIG_DEBUG_UART_SHIFT, value)
258 #define serial_din(reg) \
259 	serial_in_shift((char *)com_port + \
260 		((char *)reg - (char *)com_port) * \
261 			(1 << CONFIG_DEBUG_UART_SHIFT), \
262 		CONFIG_DEBUG_UART_SHIFT)
263 
264 static inline void _debug_uart_init(void)
265 {
266 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
267 	int baud_divisor;
268 
269 	/*
270 	 * We copy the code from above because it is already horribly messy.
271 	 * Trying to refactor to nicely remove the duplication doesn't seem
272 	 * feasible. The better fix is to move all users of this driver to
273 	 * driver model.
274 	 */
275 	baud_divisor = calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
276 				    CONFIG_BAUDRATE);
277 	serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
278 	serial_dout(&com_port->mcr, UART_MCRVAL);
279 	serial_dout(&com_port->fcr, UART_FCRVAL);
280 
281 	serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
282 	serial_dout(&com_port->dll, baud_divisor & 0xff);
283 	serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
284 	serial_dout(&com_port->lcr, UART_LCRVAL);
285 }
286 
287 static inline void _debug_uart_putc(int ch)
288 {
289 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
290 
291 	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
292 		;
293 	serial_dout(&com_port->thr, ch);
294 }
295 
296 DEBUG_UART_FUNCS
297 
298 #endif
299 
300 #ifdef CONFIG_DM_SERIAL
301 static int ns16550_serial_putc(struct udevice *dev, const char ch)
302 {
303 	struct NS16550 *const com_port = dev_get_priv(dev);
304 
305 	if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
306 		return -EAGAIN;
307 	serial_out(ch, &com_port->thr);
308 
309 	/*
310 	 * Call watchdog_reset() upon newline. This is done here in putc
311 	 * since the environment code uses a single puts() to print the complete
312 	 * environment upon "printenv". So we can't put this watchdog call
313 	 * in puts().
314 	 */
315 	if (ch == '\n')
316 		WATCHDOG_RESET();
317 
318 	return 0;
319 }
320 
321 static int ns16550_serial_pending(struct udevice *dev, bool input)
322 {
323 	struct NS16550 *const com_port = dev_get_priv(dev);
324 
325 	if (input)
326 		return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
327 	else
328 		return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
329 }
330 
331 static int ns16550_serial_getc(struct udevice *dev)
332 {
333 	struct NS16550 *const com_port = dev_get_priv(dev);
334 
335 	if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
336 		return -EAGAIN;
337 
338 	return serial_in(&com_port->rbr);
339 }
340 
341 static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
342 {
343 	struct NS16550 *const com_port = dev_get_priv(dev);
344 	struct ns16550_platdata *plat = com_port->plat;
345 	int clock_divisor;
346 
347 	clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
348 
349 	NS16550_setbrg(com_port, clock_divisor);
350 
351 	return 0;
352 }
353 
354 int ns16550_serial_probe(struct udevice *dev)
355 {
356 	struct NS16550 *const com_port = dev_get_priv(dev);
357 
358 	com_port->plat = dev_get_platdata(dev);
359 	NS16550_init(com_port, -1);
360 
361 	return 0;
362 }
363 
364 #if CONFIG_IS_ENABLED(OF_CONTROL)
365 int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
366 {
367 	struct ns16550_platdata *plat = dev->platdata;
368 	fdt_addr_t addr;
369 
370 	/* try Processor Local Bus device first */
371 	addr = dev_get_addr(dev);
372 #if defined(CONFIG_PCI) && defined(CONFIG_DM_PCI)
373 	if (addr == FDT_ADDR_T_NONE) {
374 		/* then try pci device */
375 		struct fdt_pci_addr pci_addr;
376 		u32 bar;
377 		int ret;
378 
379 		/* we prefer to use a memory-mapped register */
380 		ret = fdtdec_get_pci_addr(gd->fdt_blob, dev->of_offset,
381 					  FDT_PCI_SPACE_MEM32, "reg",
382 					  &pci_addr);
383 		if (ret) {
384 			/* try if there is any i/o-mapped register */
385 			ret = fdtdec_get_pci_addr(gd->fdt_blob,
386 						  dev->of_offset,
387 						  FDT_PCI_SPACE_IO,
388 						  "reg", &pci_addr);
389 			if (ret)
390 				return ret;
391 		}
392 
393 		ret = fdtdec_get_pci_bar32(dev, &pci_addr, &bar);
394 		if (ret)
395 			return ret;
396 
397 		addr = bar;
398 	}
399 #endif
400 
401 	if (addr == FDT_ADDR_T_NONE)
402 		return -EINVAL;
403 
404 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
405 	plat->base = addr;
406 #else
407 	plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
408 #endif
409 
410 	plat->reg_offset = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
411 				     "reg-offset", 0);
412 	plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
413 					 "reg-shift", 0);
414 	plat->clock = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
415 				     "clock-frequency",
416 				     CONFIG_SYS_NS16550_CLK);
417 	if (!plat->clock) {
418 		debug("ns16550 clock not defined\n");
419 		return -EINVAL;
420 	}
421 
422 	return 0;
423 }
424 #endif
425 
426 const struct dm_serial_ops ns16550_serial_ops = {
427 	.putc = ns16550_serial_putc,
428 	.pending = ns16550_serial_pending,
429 	.getc = ns16550_serial_getc,
430 	.setbrg = ns16550_serial_setbrg,
431 };
432 
433 #if CONFIG_IS_ENABLED(OF_CONTROL)
434 /*
435  * Please consider existing compatible strings before adding a new
436  * one to keep this table compact. Or you may add a generic "ns16550"
437  * compatible string to your dts.
438  */
439 static const struct udevice_id ns16550_serial_ids[] = {
440 	{ .compatible = "ns16550" },
441 	{ .compatible = "ns16550a" },
442 	{ .compatible = "nvidia,tegra20-uart" },
443 	{ .compatible = "snps,dw-apb-uart" },
444 	{ .compatible = "ti,omap2-uart" },
445 	{ .compatible = "ti,omap3-uart" },
446 	{ .compatible = "ti,omap4-uart" },
447 	{ .compatible = "ti,am3352-uart" },
448 	{ .compatible = "ti,am4372-uart" },
449 	{ .compatible = "ti,dra742-uart" },
450 	{}
451 };
452 #endif
453 
454 #if CONFIG_IS_ENABLED(SERIAL_PRESENT)
455 U_BOOT_DRIVER(ns16550_serial) = {
456 	.name	= "ns16550_serial",
457 	.id	= UCLASS_SERIAL,
458 #if CONFIG_IS_ENABLED(OF_CONTROL)
459 	.of_match = ns16550_serial_ids,
460 	.ofdata_to_platdata = ns16550_serial_ofdata_to_platdata,
461 	.platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
462 #endif
463 	.priv_auto_alloc_size = sizeof(struct NS16550),
464 	.probe = ns16550_serial_probe,
465 	.ops	= &ns16550_serial_ops,
466 	.flags	= DM_FLAG_PRE_RELOC,
467 };
468 #endif
469 #endif /* CONFIG_DM_SERIAL */
470