summaryrefslogtreecommitdiff
path: root/drivers/serial/ns16550.c
blob: d7a3cf665e653e81da0639d4fad69318c22fcab4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
/*
 * COM1 NS16550 support
 * originally from linux source (arch/powerpc/boot/ns16550.c)
 * modified to use CONFIG_SYS_ISA_MEM and new defines
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <ns16550.h>
#include <serial.h>
#include <watchdog.h>
#include <linux/types.h>
#include <asm/io.h>

DECLARE_GLOBAL_DATA_PTR;

#define UART_LCRVAL UART_LCR_8N1		/* 8 data, 1 stop, no parity */
#define UART_MCRVAL (UART_MCR_DTR | \
		     UART_MCR_RTS)		/* RTS/DTR */
#define UART_FCRVAL (UART_FCR_FIFO_EN |	\
		     UART_FCR_RXSR |	\
		     UART_FCR_TXSR)		/* Clear & enable FIFOs */

#ifndef CONFIG_DM_SERIAL
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
#define serial_out(x, y)	outb(x, (ulong)y)
#define serial_in(y)		inb((ulong)y)
#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
#define serial_out(x, y)	out_be32(y, x)
#define serial_in(y)		in_be32(y)
#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
#define serial_out(x, y)	out_le32(y, x)
#define serial_in(y)		in_le32(y)
#else
#define serial_out(x, y)	writeb(x, y)
#define serial_in(y)		readb(y)
#endif
#endif /* !CONFIG_DM_SERIAL */

#if defined(CONFIG_SOC_KEYSTONE)
#define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE   0
#define UART_REG_VAL_PWREMU_MGMT_UART_ENABLE ((1 << 14) | (1 << 13) | (1 << 0))
#undef UART_MCRVAL
#ifdef CONFIG_SERIAL_HW_FLOW_CONTROL
#define UART_MCRVAL             (UART_MCR_RTS | UART_MCR_AFE)
#else
#define UART_MCRVAL             (UART_MCR_RTS)
#endif
#endif

#ifndef CONFIG_SYS_NS16550_IER
#define CONFIG_SYS_NS16550_IER  0x00
#endif /* CONFIG_SYS_NS16550_IER */

#ifdef CONFIG_DM_SERIAL

#ifndef CONFIG_SYS_NS16550_CLK
#define CONFIG_SYS_NS16550_CLK  0
#endif

static inline void serial_out_shift(void *addr, int shift, int value)
{
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
	outb(value, (ulong)addr);
#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
	out_le32(addr, value);
#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
	out_be32(addr, value);
#elif defined(CONFIG_SYS_NS16550_MEM32)
	writel(value, addr);
#elif defined(CONFIG_SYS_BIG_ENDIAN)
	writeb(value, addr + (1 << shift) - 1);
#else
	writeb(value, addr);
#endif
}

static inline int serial_in_shift(void *addr, int shift)
{
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
	return inb((ulong)addr);
#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
	return in_le32(addr);
#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
	return in_be32(addr);
#elif defined(CONFIG_SYS_NS16550_MEM32)
	return readl(addr);
#elif defined(CONFIG_SYS_BIG_ENDIAN)
	return readb(addr + (1 << shift) - 1);
#else
	return readb(addr);
#endif
}

static void ns16550_writeb(NS16550_t port, int offset, int value)
{
	struct ns16550_platdata *plat = port->plat;
	unsigned char *addr;

	offset *= 1 << plat->reg_shift;
	addr = (unsigned char *)plat->base + offset;

	/*
	 * As far as we know it doesn't make sense to support selection of
	 * these options at run-time, so use the existing CONFIG options.
	 */
	serial_out_shift(addr + plat->reg_offset, plat->reg_shift, value);
}

static int ns16550_readb(NS16550_t port, int offset)
{
	struct ns16550_platdata *plat = port->plat;
	unsigned char *addr;

	offset *= 1 << plat->reg_shift;
	addr = (unsigned char *)plat->base + offset;

	return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
}

/* We can clean these up once everything is moved to driver model */
#define serial_out(value, addr)	\
	ns16550_writeb(com_port, \
		(unsigned char *)addr - (unsigned char *)com_port, value)
#define serial_in(addr) \
	ns16550_readb(com_port, \
		(unsigned char *)addr - (unsigned char *)com_port)
#endif

static inline int calc_divisor(NS16550_t port, int clock, int baudrate)
{
	const unsigned int mode_x_div = 16;

	return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
}

int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
{
#ifdef CONFIG_OMAP1510
	/* If can't cleanly clock 115200 set div to 1 */
	if ((clock == 12000000) && (baudrate == 115200)) {
		port->osc_12m_sel = OSC_12M_SEL;  /* enable 6.5 * divisor */
		return 1;			/* return 1 for base divisor */
	}
	port->osc_12m_sel = 0;			/* clear if previsouly set */
#endif

	return calc_divisor(port, clock, baudrate);
}

static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
{
	serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
	serial_out(baud_divisor & 0xff, &com_port->dll);
	serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
	serial_out(UART_LCRVAL, &com_port->lcr);
}

void NS16550_init(NS16550_t com_port, int baud_divisor)
{
#if (defined(CONFIG_SPL_BUILD) && \
		(defined(CONFIG_OMAP34XX) || defined(CONFIG_OMAP44XX)))
	/*
	 * On some OMAP3/OMAP4 devices when UART3 is configured for boot mode
	 * before SPL starts only THRE bit is set. We have to empty the
	 * transmitter before initialization starts.
	 */
	if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
	     == UART_LSR_THRE) {
		if (baud_divisor != -1)
			NS16550_setbrg(com_port, baud_divisor);
		serial_out(0, &com_port->mdr1);
	}
#endif

	while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
		;

	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
#if defined(CONFIG_OMAP) || defined(CONFIG_AM33XX) || \
			defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
	serial_out(0x7, &com_port->mdr1);	/* mode select reset TL16C750*/
#endif
	serial_out(UART_MCRVAL, &com_port->mcr);
	serial_out(UART_FCRVAL, &com_port->fcr);
	if (baud_divisor != -1)
		NS16550_setbrg(com_port, baud_divisor);
#if defined(CONFIG_OMAP) || \
	defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \
	defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)

	/* /16 is proper to hit 115200 with 48MHz */
	serial_out(0, &com_port->mdr1);
#endif /* CONFIG_OMAP */
#if defined(CONFIG_SOC_KEYSTONE)
	serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
#endif
}

#ifndef CONFIG_NS16550_MIN_FUNCTIONS
void NS16550_reinit(NS16550_t com_port, int baud_divisor)
{
	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
	NS16550_setbrg(com_port, 0);
	serial_out(UART_MCRVAL, &com_port->mcr);
	serial_out(UART_FCRVAL, &com_port->fcr);
	NS16550_setbrg(com_port, baud_divisor);
}
#endif /* CONFIG_NS16550_MIN_FUNCTIONS */

void NS16550_putc(NS16550_t com_port, char c)
{
	while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
		;
	serial_out(c, &com_port->thr);

	/*
	 * Call watchdog_reset() upon newline. This is done here in putc
	 * since the environment code uses a single puts() to print the complete
	 * environment upon "printenv". So we can't put this watchdog call
	 * in puts().
	 */
	if (c == '\n')
		WATCHDOG_RESET();
}

#ifndef CONFIG_NS16550_MIN_FUNCTIONS
char NS16550_getc(NS16550_t com_port)
{
	while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
#if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
		extern void usbtty_poll(void);
		usbtty_poll();
#endif
		WATCHDOG_RESET();
	}
	return serial_in(&com_port->rbr);
}

int NS16550_tstc(NS16550_t com_port)
{
	return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
}

#endif /* CONFIG_NS16550_MIN_FUNCTIONS */

#ifdef CONFIG_DEBUG_UART_NS16550

#include <debug_uart.h>

#define serial_dout(reg, value)	\
	serial_out_shift((char *)com_port + \
		((char *)reg - (char *)com_port) * \
			(1 << CONFIG_DEBUG_UART_SHIFT), \
		CONFIG_DEBUG_UART_SHIFT, value)
#define serial_din(reg) \
	serial_in_shift((char *)com_port + \
		((char *)reg - (char *)com_port) * \
			(1 << CONFIG_DEBUG_UART_SHIFT), \
		CONFIG_DEBUG_UART_SHIFT)

static inline void _debug_uart_init(void)
{
	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
	int baud_divisor;

	/*
	 * We copy the code from above because it is already horribly messy.
	 * Trying to refactor to nicely remove the duplication doesn't seem
	 * feasible. The better fix is to move all users of this driver to
	 * driver model.
	 */
	baud_divisor = calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
				    CONFIG_BAUDRATE);
	serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
	serial_dout(&com_port->mcr, UART_MCRVAL);
	serial_dout(&com_port->fcr, UART_FCRVAL);

	serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
	serial_dout(&com_port->dll, baud_divisor & 0xff);
	serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
	serial_dout(&com_port->lcr, UART_LCRVAL);
}

static inline void _debug_uart_putc(int ch)
{
	struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;

	while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
		;
	serial_dout(&com_port->thr, ch);
}

DEBUG_UART_FUNCS

#endif

#ifdef CONFIG_DM_SERIAL
static int ns16550_serial_putc(struct udevice *dev, const char ch)
{
	struct NS16550 *const com_port = dev_get_priv(dev);

	if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
		return -EAGAIN;
	serial_out(ch, &com_port->thr);

	/*
	 * Call watchdog_reset() upon newline. This is done here in putc
	 * since the environment code uses a single puts() to print the complete
	 * environment upon "printenv". So we can't put this watchdog call
	 * in puts().
	 */
	if (ch == '\n')
		WATCHDOG_RESET();

	return 0;
}

static int ns16550_serial_pending(struct udevice *dev, bool input)
{
	struct NS16550 *const com_port = dev_get_priv(dev);

	if (input)
		return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
	else
		return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
}

static int ns16550_serial_getc(struct udevice *dev)
{
	struct NS16550 *const com_port = dev_get_priv(dev);

	if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
		return -EAGAIN;

	return serial_in(&com_port->rbr);
}

static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
{
	struct NS16550 *const com_port = dev_get_priv(dev);
	struct ns16550_platdata *plat = com_port->plat;
	int clock_divisor;

	clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);

	NS16550_setbrg(com_port, clock_divisor);

	return 0;
}

int ns16550_serial_probe(struct udevice *dev)
{
	struct NS16550 *const com_port = dev_get_priv(dev);

	com_port->plat = dev_get_platdata(dev);
	NS16550_init(com_port, -1);

	return 0;
}

#if CONFIG_IS_ENABLED(OF_CONTROL)
int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
{
	struct ns16550_platdata *plat = dev->platdata;
	fdt_addr_t addr;

	/* try Processor Local Bus device first */
	addr = dev_get_addr(dev);
#if defined(CONFIG_PCI) && defined(CONFIG_DM_PCI)
	if (addr == FDT_ADDR_T_NONE) {
		/* then try pci device */
		struct fdt_pci_addr pci_addr;
		u32 bar;
		int ret;

		/* we prefer to use a memory-mapped register */
		ret = fdtdec_get_pci_addr(gd->fdt_blob, dev->of_offset,
					  FDT_PCI_SPACE_MEM32, "reg",
					  &pci_addr);
		if (ret) {
			/* try if there is any i/o-mapped register */
			ret = fdtdec_get_pci_addr(gd->fdt_blob,
						  dev->of_offset,
						  FDT_PCI_SPACE_IO,
						  "reg", &pci_addr);
			if (ret)
				return ret;
		}

		ret = fdtdec_get_pci_bar32(dev, &pci_addr, &bar);
		if (ret)
			return ret;

		addr = bar;
	}
#endif

	if (addr == FDT_ADDR_T_NONE)
		return -EINVAL;

#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
	plat->base = addr;
#else
	plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
#endif

	plat->reg_offset = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
				     "reg-offset", 0);
	plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
					 "reg-shift", 0);
	plat->clock = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
				     "clock-frequency",
				     CONFIG_SYS_NS16550_CLK);
	if (!plat->clock) {
		debug("ns16550 clock not defined\n");
		return -EINVAL;
	}

	return 0;
}
#endif

const struct dm_serial_ops ns16550_serial_ops = {
	.putc = ns16550_serial_putc,
	.pending = ns16550_serial_pending,
	.getc = ns16550_serial_getc,
	.setbrg = ns16550_serial_setbrg,
};

#if CONFIG_IS_ENABLED(OF_CONTROL)
/*
 * Please consider existing compatible strings before adding a new
 * one to keep this table compact. Or you may add a generic "ns16550"
 * compatible string to your dts.
 */
static const struct udevice_id ns16550_serial_ids[] = {
	{ .compatible = "ns16550" },
	{ .compatible = "ns16550a" },
	{ .compatible = "nvidia,tegra20-uart" },
	{ .compatible = "snps,dw-apb-uart" },
	{ .compatible = "ti,omap2-uart" },
	{ .compatible = "ti,omap3-uart" },
	{ .compatible = "ti,omap4-uart" },
	{ .compatible = "ti,am3352-uart" },
	{ .compatible = "ti,am4372-uart" },
	{ .compatible = "ti,dra742-uart" },
	{}
};
#endif

#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
U_BOOT_DRIVER(ns16550_serial) = {
	.name	= "ns16550_serial",
	.id	= UCLASS_SERIAL,
#if CONFIG_IS_ENABLED(OF_CONTROL)
	.of_match = ns16550_serial_ids,
	.ofdata_to_platdata = ns16550_serial_ofdata_to_platdata,
	.platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
#endif
	.priv_auto_alloc_size = sizeof(struct NS16550),
	.probe = ns16550_serial_probe,
	.ops	= &ns16550_serial_ops,
	.flags	= DM_FLAG_PRE_RELOC,
};
#endif
#endif /* CONFIG_DM_SERIAL */