xref: /openbmc/u-boot/drivers/serial/ns16550.c (revision 60570df1)
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 <mapmem.h>
12 #include <ns16550.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 #define UART_FCRVAL (UART_FCR_FIFO_EN |	\
24 		     UART_FCR_RXSR |	\
25 		     UART_FCR_TXSR)		/* Clear & enable FIFOs */
26 
27 #ifndef CONFIG_DM_SERIAL
28 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
29 #define serial_out(x, y)	outb(x, (ulong)y)
30 #define serial_in(y)		inb((ulong)y)
31 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
32 #define serial_out(x, y)	out_be32(y, x)
33 #define serial_in(y)		in_be32(y)
34 #elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
35 #define serial_out(x, y)	out_le32(y, x)
36 #define serial_in(y)		in_le32(y)
37 #else
38 #define serial_out(x, y)	writeb(x, y)
39 #define serial_in(y)		readb(y)
40 #endif
41 #endif /* !CONFIG_DM_SERIAL */
42 
43 #if defined(CONFIG_SOC_KEYSTONE)
44 #define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE   0
45 #define UART_REG_VAL_PWREMU_MGMT_UART_ENABLE ((1 << 14) | (1 << 13) | (1 << 0))
46 #undef UART_MCRVAL
47 #ifdef CONFIG_SERIAL_HW_FLOW_CONTROL
48 #define UART_MCRVAL             (UART_MCR_RTS | UART_MCR_AFE)
49 #else
50 #define UART_MCRVAL             (UART_MCR_RTS)
51 #endif
52 #endif
53 
54 #ifndef CONFIG_SYS_NS16550_IER
55 #define CONFIG_SYS_NS16550_IER  0x00
56 #endif /* CONFIG_SYS_NS16550_IER */
57 
58 #ifdef CONFIG_DM_SERIAL
59 
60 static inline void serial_out_shift(void *addr, int shift, int value)
61 {
62 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
63 	outb(value, (ulong)addr);
64 #elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
65 	out_le32(addr, value);
66 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
67 	out_be32(addr, value);
68 #elif defined(CONFIG_SYS_BIG_ENDIAN)
69 	writeb(value, addr + (1 << shift) - 1);
70 #else
71 	writeb(value, addr);
72 #endif
73 }
74 
75 static inline int serial_in_shift(void *addr, int shift)
76 {
77 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
78 	return inb((ulong)addr);
79 #elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
80 	return in_le32(addr);
81 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
82 	return in_be32(addr);
83 #elif defined(CONFIG_SYS_BIG_ENDIAN)
84 	return readb(addr + (1 << shift) - 1);
85 #else
86 	return readb(addr);
87 #endif
88 }
89 
90 static void ns16550_writeb(NS16550_t port, int offset, int value)
91 {
92 	struct ns16550_platdata *plat = port->plat;
93 	unsigned char *addr;
94 
95 	offset *= 1 << plat->reg_shift;
96 	addr = map_sysmem(plat->base, 0) + offset;
97 	/*
98 	 * As far as we know it doesn't make sense to support selection of
99 	 * these options at run-time, so use the existing CONFIG options.
100 	 */
101 	serial_out_shift(addr, plat->reg_shift, value);
102 }
103 
104 static int ns16550_readb(NS16550_t port, int offset)
105 {
106 	struct ns16550_platdata *plat = port->plat;
107 	unsigned char *addr;
108 
109 	offset *= 1 << plat->reg_shift;
110 	addr = map_sysmem(plat->base, 0) + offset;
111 
112 	return serial_in_shift(addr, plat->reg_shift);
113 }
114 
115 /* We can clean these up once everything is moved to driver model */
116 #define serial_out(value, addr)	\
117 	ns16550_writeb(com_port, \
118 		(unsigned char *)addr - (unsigned char *)com_port, value)
119 #define serial_in(addr) \
120 	ns16550_readb(com_port, \
121 		(unsigned char *)addr - (unsigned char *)com_port)
122 #endif
123 
124 static inline int calc_divisor(NS16550_t port, int clock, int baudrate)
125 {
126 	const unsigned int mode_x_div = 16;
127 
128 	return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
129 }
130 
131 int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
132 {
133 #ifdef CONFIG_OMAP1510
134 	/* If can't cleanly clock 115200 set div to 1 */
135 	if ((clock == 12000000) && (baudrate == 115200)) {
136 		port->osc_12m_sel = OSC_12M_SEL;  /* enable 6.5 * divisor */
137 		return 1;			/* return 1 for base divisor */
138 	}
139 	port->osc_12m_sel = 0;			/* clear if previsouly set */
140 #endif
141 
142 	return calc_divisor(port, clock, baudrate);
143 }
144 
145 static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
146 {
147 	serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
148 	serial_out(baud_divisor & 0xff, &com_port->dll);
149 	serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
150 	serial_out(UART_LCRVAL, &com_port->lcr);
151 }
152 
153 void NS16550_init(NS16550_t com_port, int baud_divisor)
154 {
155 #if (defined(CONFIG_SPL_BUILD) && \
156 		(defined(CONFIG_OMAP34XX) || defined(CONFIG_OMAP44XX)))
157 	/*
158 	 * On some OMAP3/OMAP4 devices when UART3 is configured for boot mode
159 	 * before SPL starts only THRE bit is set. We have to empty the
160 	 * transmitter before initialization starts.
161 	 */
162 	if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
163 	     == UART_LSR_THRE) {
164 		if (baud_divisor != -1)
165 			NS16550_setbrg(com_port, baud_divisor);
166 		serial_out(0, &com_port->mdr1);
167 	}
168 #endif
169 
170 	while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
171 		;
172 
173 	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
174 #if defined(CONFIG_OMAP) || defined(CONFIG_AM33XX) || \
175 			defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
176 	serial_out(0x7, &com_port->mdr1);	/* mode select reset TL16C750*/
177 #endif
178 	serial_out(UART_MCRVAL, &com_port->mcr);
179 	serial_out(UART_FCRVAL, &com_port->fcr);
180 	if (baud_divisor != -1)
181 		NS16550_setbrg(com_port, baud_divisor);
182 #if defined(CONFIG_OMAP) || \
183 	defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \
184 	defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
185 
186 	/* /16 is proper to hit 115200 with 48MHz */
187 	serial_out(0, &com_port->mdr1);
188 #endif /* CONFIG_OMAP */
189 #if defined(CONFIG_SOC_KEYSTONE)
190 	serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
191 #endif
192 }
193 
194 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
195 void NS16550_reinit(NS16550_t com_port, int baud_divisor)
196 {
197 	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
198 	NS16550_setbrg(com_port, 0);
199 	serial_out(UART_MCRVAL, &com_port->mcr);
200 	serial_out(UART_FCRVAL, &com_port->fcr);
201 	NS16550_setbrg(com_port, baud_divisor);
202 }
203 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
204 
205 void NS16550_putc(NS16550_t com_port, char c)
206 {
207 	while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
208 		;
209 	serial_out(c, &com_port->thr);
210 
211 	/*
212 	 * Call watchdog_reset() upon newline. This is done here in putc
213 	 * since the environment code uses a single puts() to print the complete
214 	 * environment upon "printenv". So we can't put this watchdog call
215 	 * in puts().
216 	 */
217 	if (c == '\n')
218 		WATCHDOG_RESET();
219 }
220 
221 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
222 char NS16550_getc(NS16550_t com_port)
223 {
224 	while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
225 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
226 		extern void usbtty_poll(void);
227 		usbtty_poll();
228 #endif
229 		WATCHDOG_RESET();
230 	}
231 	return serial_in(&com_port->rbr);
232 }
233 
234 int NS16550_tstc(NS16550_t com_port)
235 {
236 	return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
237 }
238 
239 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
240 
241 #ifdef CONFIG_DEBUG_UART_NS16550
242 
243 #include <debug_uart.h>
244 
245 void debug_uart_init(void)
246 {
247 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
248 	int baud_divisor;
249 
250 	/*
251 	 * We copy the code from above because it is already horribly messy.
252 	 * Trying to refactor to nicely remove the duplication doesn't seem
253 	 * feasible. The better fix is to move all users of this driver to
254 	 * driver model.
255 	 */
256 	baud_divisor = calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
257 				    CONFIG_BAUDRATE);
258 	serial_out_shift(&com_port->ier, CONFIG_DEBUG_UART_SHIFT,
259 			 CONFIG_SYS_NS16550_IER);
260 	serial_out_shift(&com_port->mcr, CONFIG_DEBUG_UART_SHIFT, UART_MCRVAL);
261 	serial_out_shift(&com_port->fcr, CONFIG_DEBUG_UART_SHIFT, UART_FCRVAL);
262 
263 	serial_out_shift(&com_port->lcr, CONFIG_DEBUG_UART_SHIFT,
264 			 UART_LCR_BKSE | UART_LCRVAL);
265 	serial_out_shift(&com_port->dll, CONFIG_DEBUG_UART_SHIFT,
266 			 baud_divisor & 0xff);
267 	serial_out_shift(&com_port->dlm, CONFIG_DEBUG_UART_SHIFT,
268 			 (baud_divisor >> 8) & 0xff);
269 	serial_out_shift(&com_port->lcr, CONFIG_DEBUG_UART_SHIFT,
270 			 UART_LCRVAL);
271 }
272 
273 static inline void _debug_uart_putc(int ch)
274 {
275 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
276 
277 	while (!(serial_in_shift(&com_port->lsr, 0) & UART_LSR_THRE))
278 		;
279 	serial_out_shift(&com_port->thr, CONFIG_DEBUG_UART_SHIFT, ch);
280 }
281 
282 DEBUG_UART_FUNCS
283 
284 #endif
285 
286 #ifdef CONFIG_DM_SERIAL
287 static int ns16550_serial_putc(struct udevice *dev, const char ch)
288 {
289 	struct NS16550 *const com_port = dev_get_priv(dev);
290 
291 	if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
292 		return -EAGAIN;
293 	serial_out(ch, &com_port->thr);
294 
295 	/*
296 	 * Call watchdog_reset() upon newline. This is done here in putc
297 	 * since the environment code uses a single puts() to print the complete
298 	 * environment upon "printenv". So we can't put this watchdog call
299 	 * in puts().
300 	 */
301 	if (ch == '\n')
302 		WATCHDOG_RESET();
303 
304 	return 0;
305 }
306 
307 static int ns16550_serial_pending(struct udevice *dev, bool input)
308 {
309 	struct NS16550 *const com_port = dev_get_priv(dev);
310 
311 	if (input)
312 		return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
313 	else
314 		return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
315 }
316 
317 static int ns16550_serial_getc(struct udevice *dev)
318 {
319 	struct NS16550 *const com_port = dev_get_priv(dev);
320 
321 	if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
322 		return -EAGAIN;
323 
324 	return serial_in(&com_port->rbr);
325 }
326 
327 static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
328 {
329 	struct NS16550 *const com_port = dev_get_priv(dev);
330 	struct ns16550_platdata *plat = com_port->plat;
331 	int clock_divisor;
332 
333 	clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
334 
335 	NS16550_setbrg(com_port, clock_divisor);
336 
337 	return 0;
338 }
339 
340 int ns16550_serial_probe(struct udevice *dev)
341 {
342 	struct NS16550 *const com_port = dev_get_priv(dev);
343 
344 	com_port->plat = dev_get_platdata(dev);
345 	NS16550_init(com_port, -1);
346 
347 	return 0;
348 }
349 
350 #ifdef CONFIG_OF_CONTROL
351 int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
352 {
353 	struct ns16550_platdata *plat = dev->platdata;
354 	fdt_addr_t addr;
355 
356 	/* try Processor Local Bus device first */
357 	addr = fdtdec_get_addr(gd->fdt_blob, dev->of_offset, "reg");
358 #ifdef CONFIG_PCI
359 	if (addr == FDT_ADDR_T_NONE) {
360 		/* then try pci device */
361 		struct fdt_pci_addr pci_addr;
362 		u32 bar;
363 		int ret;
364 
365 		/* we prefer to use a memory-mapped register */
366 		ret = fdtdec_get_pci_addr(gd->fdt_blob, dev->of_offset,
367 					  FDT_PCI_SPACE_MEM32, "reg",
368 					  &pci_addr);
369 		if (ret) {
370 			/* try if there is any i/o-mapped register */
371 			ret = fdtdec_get_pci_addr(gd->fdt_blob,
372 						  dev->of_offset,
373 						  FDT_PCI_SPACE_IO,
374 						  "reg", &pci_addr);
375 			if (ret)
376 				return ret;
377 		}
378 
379 		ret = fdtdec_get_pci_bar32(gd->fdt_blob, dev->of_offset,
380 					   &pci_addr, &bar);
381 		if (ret)
382 			return ret;
383 
384 		addr = bar;
385 	}
386 #endif
387 
388 	if (addr == FDT_ADDR_T_NONE)
389 		return -EINVAL;
390 
391 	plat->base = addr;
392 	plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
393 					 "reg-shift", 1);
394 
395 	return 0;
396 }
397 #endif
398 
399 const struct dm_serial_ops ns16550_serial_ops = {
400 	.putc = ns16550_serial_putc,
401 	.pending = ns16550_serial_pending,
402 	.getc = ns16550_serial_getc,
403 	.setbrg = ns16550_serial_setbrg,
404 };
405 #endif /* CONFIG_DM_SERIAL */
406