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1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2000
4  * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
5  *
6  * (C) Copyright 2004
7  * ARM Ltd.
8  * Philippe Robin, <philippe.robin@arm.com>
9  */
10 
11 /* Simple U-Boot driver for the PrimeCell PL010/PL011 UARTs */
12 
13 #include <common.h>
14 #include <dm.h>
15 #include <errno.h>
16 #include <watchdog.h>
17 #include <asm/io.h>
18 #include <serial.h>
19 #include <dm/platform_data/serial_pl01x.h>
20 #include <linux/compiler.h>
21 #include "serial_pl01x_internal.h"
22 
23 DECLARE_GLOBAL_DATA_PTR;
24 
25 #ifndef CONFIG_DM_SERIAL
26 
27 static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
28 static enum pl01x_type pl01x_type __attribute__ ((section(".data")));
29 static struct pl01x_regs *base_regs __attribute__ ((section(".data")));
30 #define NUM_PORTS (sizeof(port)/sizeof(port[0]))
31 
32 #endif
33 
pl01x_putc(struct pl01x_regs * regs,char c)34 static int pl01x_putc(struct pl01x_regs *regs, char c)
35 {
36 	/* Wait until there is space in the FIFO */
37 	if (readl(&regs->fr) & UART_PL01x_FR_TXFF)
38 		return -EAGAIN;
39 
40 	/* Send the character */
41 	writel(c, &regs->dr);
42 
43 	return 0;
44 }
45 
pl01x_getc(struct pl01x_regs * regs)46 static int pl01x_getc(struct pl01x_regs *regs)
47 {
48 	unsigned int data;
49 
50 	/* Wait until there is data in the FIFO */
51 	if (readl(&regs->fr) & UART_PL01x_FR_RXFE)
52 		return -EAGAIN;
53 
54 	data = readl(&regs->dr);
55 
56 	/* Check for an error flag */
57 	if (data & 0xFFFFFF00) {
58 		/* Clear the error */
59 		writel(0xFFFFFFFF, &regs->ecr);
60 		return -1;
61 	}
62 
63 	return (int) data;
64 }
65 
pl01x_tstc(struct pl01x_regs * regs)66 static int pl01x_tstc(struct pl01x_regs *regs)
67 {
68 	WATCHDOG_RESET();
69 	return !(readl(&regs->fr) & UART_PL01x_FR_RXFE);
70 }
71 
pl01x_generic_serial_init(struct pl01x_regs * regs,enum pl01x_type type)72 static int pl01x_generic_serial_init(struct pl01x_regs *regs,
73 				     enum pl01x_type type)
74 {
75 	switch (type) {
76 	case TYPE_PL010:
77 		/* disable everything */
78 		writel(0, &regs->pl010_cr);
79 		break;
80 	case TYPE_PL011:
81 		/* disable everything */
82 		writel(0, &regs->pl011_cr);
83 		break;
84 	default:
85 		return -EINVAL;
86 	}
87 
88 	return 0;
89 }
90 
pl011_set_line_control(struct pl01x_regs * regs)91 static int pl011_set_line_control(struct pl01x_regs *regs)
92 {
93 	unsigned int lcr;
94 	/*
95 	 * Internal update of baud rate register require line
96 	 * control register write
97 	 */
98 	lcr = UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN;
99 	writel(lcr, &regs->pl011_lcrh);
100 	return 0;
101 }
102 
pl01x_generic_setbrg(struct pl01x_regs * regs,enum pl01x_type type,int clock,int baudrate)103 static int pl01x_generic_setbrg(struct pl01x_regs *regs, enum pl01x_type type,
104 				int clock, int baudrate)
105 {
106 	switch (type) {
107 	case TYPE_PL010: {
108 		unsigned int divisor;
109 
110 		/* disable everything */
111 		writel(0, &regs->pl010_cr);
112 
113 		switch (baudrate) {
114 		case 9600:
115 			divisor = UART_PL010_BAUD_9600;
116 			break;
117 		case 19200:
118 			divisor = UART_PL010_BAUD_19200;
119 			break;
120 		case 38400:
121 			divisor = UART_PL010_BAUD_38400;
122 			break;
123 		case 57600:
124 			divisor = UART_PL010_BAUD_57600;
125 			break;
126 		case 115200:
127 			divisor = UART_PL010_BAUD_115200;
128 			break;
129 		default:
130 			divisor = UART_PL010_BAUD_38400;
131 		}
132 
133 		writel((divisor & 0xf00) >> 8, &regs->pl010_lcrm);
134 		writel(divisor & 0xff, &regs->pl010_lcrl);
135 
136 		/*
137 		 * Set line control for the PL010 to be 8 bits, 1 stop bit,
138 		 * no parity, fifo enabled
139 		 */
140 		writel(UART_PL010_LCRH_WLEN_8 | UART_PL010_LCRH_FEN,
141 		       &regs->pl010_lcrh);
142 		/* Finally, enable the UART */
143 		writel(UART_PL010_CR_UARTEN, &regs->pl010_cr);
144 		break;
145 	}
146 	case TYPE_PL011: {
147 		unsigned int temp;
148 		unsigned int divider;
149 		unsigned int remainder;
150 		unsigned int fraction;
151 
152 		/*
153 		* Set baud rate
154 		*
155 		* IBRD = UART_CLK / (16 * BAUD_RATE)
156 		* FBRD = RND((64 * MOD(UART_CLK,(16 * BAUD_RATE)))
157 		*		/ (16 * BAUD_RATE))
158 		*/
159 		temp = 16 * baudrate;
160 		divider = clock / temp;
161 		remainder = clock % temp;
162 		temp = (8 * remainder) / baudrate;
163 		fraction = (temp >> 1) + (temp & 1);
164 
165 		writel(divider, &regs->pl011_ibrd);
166 		writel(fraction, &regs->pl011_fbrd);
167 
168 		pl011_set_line_control(regs);
169 		/* Finally, enable the UART */
170 		writel(UART_PL011_CR_UARTEN | UART_PL011_CR_TXE |
171 		       UART_PL011_CR_RXE | UART_PL011_CR_RTS, &regs->pl011_cr);
172 		break;
173 	}
174 	default:
175 		return -EINVAL;
176 	}
177 
178 	return 0;
179 }
180 
181 #ifndef CONFIG_DM_SERIAL
pl01x_serial_init_baud(int baudrate)182 static void pl01x_serial_init_baud(int baudrate)
183 {
184 	int clock = 0;
185 
186 #if defined(CONFIG_PL010_SERIAL)
187 	pl01x_type = TYPE_PL010;
188 #elif defined(CONFIG_PL011_SERIAL)
189 	pl01x_type = TYPE_PL011;
190 	clock = CONFIG_PL011_CLOCK;
191 #endif
192 	base_regs = (struct pl01x_regs *)port[CONFIG_CONS_INDEX];
193 
194 	pl01x_generic_serial_init(base_regs, pl01x_type);
195 	pl01x_generic_setbrg(base_regs, pl01x_type, clock, baudrate);
196 }
197 
198 /*
199  * Integrator AP has two UARTs, we use the first one, at 38400-8-N-1
200  * Integrator CP has two UARTs, use the first one, at 38400-8-N-1
201  * Versatile PB has four UARTs.
202  */
pl01x_serial_init(void)203 int pl01x_serial_init(void)
204 {
205 	pl01x_serial_init_baud(CONFIG_BAUDRATE);
206 
207 	return 0;
208 }
209 
pl01x_serial_putc(const char c)210 static void pl01x_serial_putc(const char c)
211 {
212 	if (c == '\n')
213 		while (pl01x_putc(base_regs, '\r') == -EAGAIN);
214 
215 	while (pl01x_putc(base_regs, c) == -EAGAIN);
216 }
217 
pl01x_serial_getc(void)218 static int pl01x_serial_getc(void)
219 {
220 	while (1) {
221 		int ch = pl01x_getc(base_regs);
222 
223 		if (ch == -EAGAIN) {
224 			WATCHDOG_RESET();
225 			continue;
226 		}
227 
228 		return ch;
229 	}
230 }
231 
pl01x_serial_tstc(void)232 static int pl01x_serial_tstc(void)
233 {
234 	return pl01x_tstc(base_regs);
235 }
236 
pl01x_serial_setbrg(void)237 static void pl01x_serial_setbrg(void)
238 {
239 	/*
240 	 * Flush FIFO and wait for non-busy before changing baudrate to avoid
241 	 * crap in console
242 	 */
243 	while (!(readl(&base_regs->fr) & UART_PL01x_FR_TXFE))
244 		WATCHDOG_RESET();
245 	while (readl(&base_regs->fr) & UART_PL01x_FR_BUSY)
246 		WATCHDOG_RESET();
247 	pl01x_serial_init_baud(gd->baudrate);
248 }
249 
250 static struct serial_device pl01x_serial_drv = {
251 	.name	= "pl01x_serial",
252 	.start	= pl01x_serial_init,
253 	.stop	= NULL,
254 	.setbrg	= pl01x_serial_setbrg,
255 	.putc	= pl01x_serial_putc,
256 	.puts	= default_serial_puts,
257 	.getc	= pl01x_serial_getc,
258 	.tstc	= pl01x_serial_tstc,
259 };
260 
pl01x_serial_initialize(void)261 void pl01x_serial_initialize(void)
262 {
263 	serial_register(&pl01x_serial_drv);
264 }
265 
default_serial_console(void)266 __weak struct serial_device *default_serial_console(void)
267 {
268 	return &pl01x_serial_drv;
269 }
270 
271 #endif /* nCONFIG_DM_SERIAL */
272 
273 #ifdef CONFIG_DM_SERIAL
274 
pl01x_serial_setbrg(struct udevice * dev,int baudrate)275 int pl01x_serial_setbrg(struct udevice *dev, int baudrate)
276 {
277 	struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
278 	struct pl01x_priv *priv = dev_get_priv(dev);
279 
280 	if (!plat->skip_init) {
281 		pl01x_generic_setbrg(priv->regs, priv->type, plat->clock,
282 				     baudrate);
283 	}
284 
285 	return 0;
286 }
287 
pl01x_serial_probe(struct udevice * dev)288 int pl01x_serial_probe(struct udevice *dev)
289 {
290 	struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
291 	struct pl01x_priv *priv = dev_get_priv(dev);
292 
293 	priv->regs = (struct pl01x_regs *)plat->base;
294 	priv->type = plat->type;
295 	if (!plat->skip_init)
296 		return pl01x_generic_serial_init(priv->regs, priv->type);
297 	else
298 		return 0;
299 }
300 
pl01x_serial_getc(struct udevice * dev)301 int pl01x_serial_getc(struct udevice *dev)
302 {
303 	struct pl01x_priv *priv = dev_get_priv(dev);
304 
305 	return pl01x_getc(priv->regs);
306 }
307 
pl01x_serial_putc(struct udevice * dev,const char ch)308 int pl01x_serial_putc(struct udevice *dev, const char ch)
309 {
310 	struct pl01x_priv *priv = dev_get_priv(dev);
311 
312 	return pl01x_putc(priv->regs, ch);
313 }
314 
pl01x_serial_pending(struct udevice * dev,bool input)315 int pl01x_serial_pending(struct udevice *dev, bool input)
316 {
317 	struct pl01x_priv *priv = dev_get_priv(dev);
318 	unsigned int fr = readl(&priv->regs->fr);
319 
320 	if (input)
321 		return pl01x_tstc(priv->regs);
322 	else
323 		return fr & UART_PL01x_FR_TXFF ? 0 : 1;
324 }
325 
326 static const struct dm_serial_ops pl01x_serial_ops = {
327 	.putc = pl01x_serial_putc,
328 	.pending = pl01x_serial_pending,
329 	.getc = pl01x_serial_getc,
330 	.setbrg = pl01x_serial_setbrg,
331 };
332 
333 #if CONFIG_IS_ENABLED(OF_CONTROL)
334 static const struct udevice_id pl01x_serial_id[] ={
335 	{.compatible = "arm,pl011", .data = TYPE_PL011},
336 	{.compatible = "arm,pl010", .data = TYPE_PL010},
337 	{}
338 };
339 
pl01x_serial_ofdata_to_platdata(struct udevice * dev)340 int pl01x_serial_ofdata_to_platdata(struct udevice *dev)
341 {
342 	struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
343 	fdt_addr_t addr;
344 
345 	addr = devfdt_get_addr(dev);
346 	if (addr == FDT_ADDR_T_NONE)
347 		return -EINVAL;
348 
349 	plat->base = addr;
350 	plat->clock = dev_read_u32_default(dev, "clock", 1);
351 	plat->type = dev_get_driver_data(dev);
352 	plat->skip_init = dev_read_bool(dev, "skip-init");
353 
354 	return 0;
355 }
356 #endif
357 
358 U_BOOT_DRIVER(serial_pl01x) = {
359 	.name	= "serial_pl01x",
360 	.id	= UCLASS_SERIAL,
361 	.of_match = of_match_ptr(pl01x_serial_id),
362 	.ofdata_to_platdata = of_match_ptr(pl01x_serial_ofdata_to_platdata),
363 	.platdata_auto_alloc_size = sizeof(struct pl01x_serial_platdata),
364 	.probe = pl01x_serial_probe,
365 	.ops	= &pl01x_serial_ops,
366 	.flags = DM_FLAG_PRE_RELOC,
367 	.priv_auto_alloc_size = sizeof(struct pl01x_priv),
368 };
369 
370 #endif
371 
372 #if defined(CONFIG_DEBUG_UART_PL010) || defined(CONFIG_DEBUG_UART_PL011)
373 
374 #include <debug_uart.h>
375 
_debug_uart_init(void)376 static void _debug_uart_init(void)
377 {
378 #ifndef CONFIG_DEBUG_UART_SKIP_INIT
379 	struct pl01x_regs *regs = (struct pl01x_regs *)CONFIG_DEBUG_UART_BASE;
380 	enum pl01x_type type = CONFIG_IS_ENABLED(DEBUG_UART_PL011) ?
381 				TYPE_PL011 : TYPE_PL010;
382 
383 	pl01x_generic_serial_init(regs, type);
384 	pl01x_generic_setbrg(regs, type,
385 			     CONFIG_DEBUG_UART_CLOCK, CONFIG_BAUDRATE);
386 #endif
387 }
388 
_debug_uart_putc(int ch)389 static inline void _debug_uart_putc(int ch)
390 {
391 	struct pl01x_regs *regs = (struct pl01x_regs *)CONFIG_DEBUG_UART_BASE;
392 
393 	pl01x_putc(regs, ch);
394 }
395 
396 DEBUG_UART_FUNCS
397 
398 #endif
399