xref: /openbmc/u-boot/drivers/serial/ns16550.c (revision 29b103c7)
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_NS16550_MEM32)
69 	writel(value, addr);
70 #elif defined(CONFIG_SYS_BIG_ENDIAN)
71 	writeb(value, addr + (1 << shift) - 1);
72 #else
73 	writeb(value, addr);
74 #endif
75 }
76 
77 static inline int serial_in_shift(void *addr, int shift)
78 {
79 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
80 	return inb((ulong)addr);
81 #elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
82 	return in_le32(addr);
83 #elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
84 	return in_be32(addr);
85 #elif defined(CONFIG_SYS_NS16550_MEM32)
86 	return readl(addr);
87 #elif defined(CONFIG_SYS_BIG_ENDIAN)
88 	return readb(addr + (1 << shift) - 1);
89 #else
90 	return readb(addr);
91 #endif
92 }
93 
94 static void ns16550_writeb(NS16550_t port, int offset, int value)
95 {
96 	struct ns16550_platdata *plat = port->plat;
97 	unsigned char *addr;
98 
99 	offset *= 1 << plat->reg_shift;
100 	addr = map_sysmem(plat->base, 0) + offset;
101 	/*
102 	 * As far as we know it doesn't make sense to support selection of
103 	 * these options at run-time, so use the existing CONFIG options.
104 	 */
105 	serial_out_shift(addr, plat->reg_shift, value);
106 }
107 
108 static int ns16550_readb(NS16550_t port, int offset)
109 {
110 	struct ns16550_platdata *plat = port->plat;
111 	unsigned char *addr;
112 
113 	offset *= 1 << plat->reg_shift;
114 	addr = map_sysmem(plat->base, 0) + offset;
115 
116 	return serial_in_shift(addr, plat->reg_shift);
117 }
118 
119 /* We can clean these up once everything is moved to driver model */
120 #define serial_out(value, addr)	\
121 	ns16550_writeb(com_port, \
122 		(unsigned char *)addr - (unsigned char *)com_port, value)
123 #define serial_in(addr) \
124 	ns16550_readb(com_port, \
125 		(unsigned char *)addr - (unsigned char *)com_port)
126 #endif
127 
128 static inline int calc_divisor(NS16550_t port, int clock, int baudrate)
129 {
130 	const unsigned int mode_x_div = 16;
131 
132 	return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
133 }
134 
135 int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
136 {
137 #ifdef CONFIG_OMAP1510
138 	/* If can't cleanly clock 115200 set div to 1 */
139 	if ((clock == 12000000) && (baudrate == 115200)) {
140 		port->osc_12m_sel = OSC_12M_SEL;  /* enable 6.5 * divisor */
141 		return 1;			/* return 1 for base divisor */
142 	}
143 	port->osc_12m_sel = 0;			/* clear if previsouly set */
144 #endif
145 
146 	return calc_divisor(port, clock, 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_OMAP) || defined(CONFIG_AM33XX) || \
179 			defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
180 	serial_out(0x7, &com_port->mdr1);	/* mode select reset TL16C750*/
181 #endif
182 	serial_out(UART_MCRVAL, &com_port->mcr);
183 	serial_out(UART_FCRVAL, &com_port->fcr);
184 	if (baud_divisor != -1)
185 		NS16550_setbrg(com_port, baud_divisor);
186 #if defined(CONFIG_OMAP) || \
187 	defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \
188 	defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
189 
190 	/* /16 is proper to hit 115200 with 48MHz */
191 	serial_out(0, &com_port->mdr1);
192 #endif /* CONFIG_OMAP */
193 #if defined(CONFIG_SOC_KEYSTONE)
194 	serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
195 #endif
196 }
197 
198 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
199 void NS16550_reinit(NS16550_t com_port, int baud_divisor)
200 {
201 	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
202 	NS16550_setbrg(com_port, 0);
203 	serial_out(UART_MCRVAL, &com_port->mcr);
204 	serial_out(UART_FCRVAL, &com_port->fcr);
205 	NS16550_setbrg(com_port, baud_divisor);
206 }
207 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
208 
209 void NS16550_putc(NS16550_t com_port, char c)
210 {
211 	while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
212 		;
213 	serial_out(c, &com_port->thr);
214 
215 	/*
216 	 * Call watchdog_reset() upon newline. This is done here in putc
217 	 * since the environment code uses a single puts() to print the complete
218 	 * environment upon "printenv". So we can't put this watchdog call
219 	 * in puts().
220 	 */
221 	if (c == '\n')
222 		WATCHDOG_RESET();
223 }
224 
225 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
226 char NS16550_getc(NS16550_t com_port)
227 {
228 	while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
229 #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
230 		extern void usbtty_poll(void);
231 		usbtty_poll();
232 #endif
233 		WATCHDOG_RESET();
234 	}
235 	return serial_in(&com_port->rbr);
236 }
237 
238 int NS16550_tstc(NS16550_t com_port)
239 {
240 	return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
241 }
242 
243 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
244 
245 #ifdef CONFIG_DEBUG_UART_NS16550
246 
247 #include <debug_uart.h>
248 
249 void debug_uart_init(void)
250 {
251 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
252 	int baud_divisor;
253 
254 	/*
255 	 * We copy the code from above because it is already horribly messy.
256 	 * Trying to refactor to nicely remove the duplication doesn't seem
257 	 * feasible. The better fix is to move all users of this driver to
258 	 * driver model.
259 	 */
260 	baud_divisor = calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
261 				    CONFIG_BAUDRATE);
262 	serial_out_shift(&com_port->ier, CONFIG_DEBUG_UART_SHIFT,
263 			 CONFIG_SYS_NS16550_IER);
264 	serial_out_shift(&com_port->mcr, CONFIG_DEBUG_UART_SHIFT, UART_MCRVAL);
265 	serial_out_shift(&com_port->fcr, CONFIG_DEBUG_UART_SHIFT, UART_FCRVAL);
266 
267 	serial_out_shift(&com_port->lcr, CONFIG_DEBUG_UART_SHIFT,
268 			 UART_LCR_BKSE | UART_LCRVAL);
269 	serial_out_shift(&com_port->dll, CONFIG_DEBUG_UART_SHIFT,
270 			 baud_divisor & 0xff);
271 	serial_out_shift(&com_port->dlm, CONFIG_DEBUG_UART_SHIFT,
272 			 (baud_divisor >> 8) & 0xff);
273 	serial_out_shift(&com_port->lcr, CONFIG_DEBUG_UART_SHIFT,
274 			 UART_LCRVAL);
275 }
276 
277 static inline void _debug_uart_putc(int ch)
278 {
279 	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
280 
281 	while (!(serial_in_shift(&com_port->lsr, 0) & UART_LSR_THRE))
282 		;
283 	serial_out_shift(&com_port->thr, CONFIG_DEBUG_UART_SHIFT, ch);
284 }
285 
286 DEBUG_UART_FUNCS
287 
288 #endif
289 
290 #ifdef CONFIG_DM_SERIAL
291 static int ns16550_serial_putc(struct udevice *dev, const char ch)
292 {
293 	struct NS16550 *const com_port = dev_get_priv(dev);
294 
295 	if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
296 		return -EAGAIN;
297 	serial_out(ch, &com_port->thr);
298 
299 	/*
300 	 * Call watchdog_reset() upon newline. This is done here in putc
301 	 * since the environment code uses a single puts() to print the complete
302 	 * environment upon "printenv". So we can't put this watchdog call
303 	 * in puts().
304 	 */
305 	if (ch == '\n')
306 		WATCHDOG_RESET();
307 
308 	return 0;
309 }
310 
311 static int ns16550_serial_pending(struct udevice *dev, bool input)
312 {
313 	struct NS16550 *const com_port = dev_get_priv(dev);
314 
315 	if (input)
316 		return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
317 	else
318 		return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
319 }
320 
321 static int ns16550_serial_getc(struct udevice *dev)
322 {
323 	struct NS16550 *const com_port = dev_get_priv(dev);
324 
325 	if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
326 		return -EAGAIN;
327 
328 	return serial_in(&com_port->rbr);
329 }
330 
331 static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
332 {
333 	struct NS16550 *const com_port = dev_get_priv(dev);
334 	struct ns16550_platdata *plat = com_port->plat;
335 	int clock_divisor;
336 
337 	clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
338 
339 	NS16550_setbrg(com_port, clock_divisor);
340 
341 	return 0;
342 }
343 
344 int ns16550_serial_probe(struct udevice *dev)
345 {
346 	struct NS16550 *const com_port = dev_get_priv(dev);
347 
348 	com_port->plat = dev_get_platdata(dev);
349 	NS16550_init(com_port, -1);
350 
351 	return 0;
352 }
353 
354 #ifdef CONFIG_OF_CONTROL
355 int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
356 {
357 	struct ns16550_platdata *plat = dev->platdata;
358 	fdt_addr_t addr;
359 
360 	/* try Processor Local Bus device first */
361 	addr = fdtdec_get_addr(gd->fdt_blob, dev->of_offset, "reg");
362 #ifdef CONFIG_PCI
363 	if (addr == FDT_ADDR_T_NONE) {
364 		/* then try pci device */
365 		struct fdt_pci_addr pci_addr;
366 		u32 bar;
367 		int ret;
368 
369 		/* we prefer to use a memory-mapped register */
370 		ret = fdtdec_get_pci_addr(gd->fdt_blob, dev->of_offset,
371 					  FDT_PCI_SPACE_MEM32, "reg",
372 					  &pci_addr);
373 		if (ret) {
374 			/* try if there is any i/o-mapped register */
375 			ret = fdtdec_get_pci_addr(gd->fdt_blob,
376 						  dev->of_offset,
377 						  FDT_PCI_SPACE_IO,
378 						  "reg", &pci_addr);
379 			if (ret)
380 				return ret;
381 		}
382 
383 		ret = fdtdec_get_pci_bar32(gd->fdt_blob, dev->of_offset,
384 					   &pci_addr, &bar);
385 		if (ret)
386 			return ret;
387 
388 		addr = bar;
389 	}
390 #endif
391 
392 	if (addr == FDT_ADDR_T_NONE)
393 		return -EINVAL;
394 
395 	plat->base = addr;
396 	plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
397 					 "reg-shift", 1);
398 
399 	return 0;
400 }
401 #endif
402 
403 const struct dm_serial_ops ns16550_serial_ops = {
404 	.putc = ns16550_serial_putc,
405 	.pending = ns16550_serial_pending,
406 	.getc = ns16550_serial_getc,
407 	.setbrg = ns16550_serial_setbrg,
408 };
409 #endif /* CONFIG_DM_SERIAL */
410