xref: /openbmc/u-boot/drivers/serial/serial_sh.c (revision 3ebd892f)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * SuperH SCIF device driver.
4  * Copyright (C) 2013  Renesas Electronics Corporation
5  * Copyright (C) 2007,2008,2010, 2014 Nobuhiro Iwamatsu
6  * Copyright (C) 2002 - 2008  Paul Mundt
7  */
8 
9 #include <common.h>
10 #include <errno.h>
11 #include <clk.h>
12 #include <dm.h>
13 #include <asm/io.h>
14 #include <asm/processor.h>
15 #include <serial.h>
16 #include <linux/compiler.h>
17 #include <dm/platform_data/serial_sh.h>
18 #include "serial_sh.h"
19 
20 DECLARE_GLOBAL_DATA_PTR;
21 
22 #if defined(CONFIG_CPU_SH7760) || \
23 	defined(CONFIG_CPU_SH7780) || \
24 	defined(CONFIG_CPU_SH7785) || \
25 	defined(CONFIG_CPU_SH7786)
26 static int scif_rxfill(struct uart_port *port)
27 {
28 	return sci_in(port, SCRFDR) & 0xff;
29 }
30 #elif defined(CONFIG_CPU_SH7763)
31 static int scif_rxfill(struct uart_port *port)
32 {
33 	if ((port->mapbase == 0xffe00000) ||
34 	    (port->mapbase == 0xffe08000)) {
35 		/* SCIF0/1*/
36 		return sci_in(port, SCRFDR) & 0xff;
37 	} else {
38 		/* SCIF2 */
39 		return sci_in(port, SCFDR) & SCIF2_RFDC_MASK;
40 	}
41 }
42 #elif defined(CONFIG_ARCH_SH7372)
43 static int scif_rxfill(struct uart_port *port)
44 {
45 	if (port->type == PORT_SCIFA)
46 		return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
47 	else
48 		return sci_in(port, SCRFDR);
49 }
50 #else
51 static int scif_rxfill(struct uart_port *port)
52 {
53 	return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
54 }
55 #endif
56 
57 static void sh_serial_init_generic(struct uart_port *port)
58 {
59 	sci_out(port, SCSCR , SCSCR_INIT(port));
60 	sci_out(port, SCSCR , SCSCR_INIT(port));
61 	sci_out(port, SCSMR, 0);
62 	sci_out(port, SCSMR, 0);
63 	sci_out(port, SCFCR, SCFCR_RFRST|SCFCR_TFRST);
64 	sci_in(port, SCFCR);
65 	sci_out(port, SCFCR, 0);
66 }
67 
68 static void
69 sh_serial_setbrg_generic(struct uart_port *port, int clk, int baudrate)
70 {
71 	if (port->clk_mode == EXT_CLK) {
72 		unsigned short dl = DL_VALUE(baudrate, clk);
73 		sci_out(port, DL, dl);
74 		/* Need wait: Clock * 1/dl * 1/16 */
75 		udelay((1000000 * dl * 16 / clk) * 1000 + 1);
76 	} else {
77 		sci_out(port, SCBRR, SCBRR_VALUE(baudrate, clk));
78 	}
79 }
80 
81 static void handle_error(struct uart_port *port)
82 {
83 	sci_in(port, SCxSR);
84 	sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
85 	sci_in(port, SCLSR);
86 	sci_out(port, SCLSR, 0x00);
87 }
88 
89 static int serial_raw_putc(struct uart_port *port, const char c)
90 {
91 	/* Tx fifo is empty */
92 	if (!(sci_in(port, SCxSR) & SCxSR_TEND(port)))
93 		return -EAGAIN;
94 
95 	sci_out(port, SCxTDR, c);
96 	sci_out(port, SCxSR, sci_in(port, SCxSR) & ~SCxSR_TEND(port));
97 
98 	return 0;
99 }
100 
101 static int serial_rx_fifo_level(struct uart_port *port)
102 {
103 	return scif_rxfill(port);
104 }
105 
106 static int sh_serial_tstc_generic(struct uart_port *port)
107 {
108 	if (sci_in(port, SCxSR) & SCIF_ERRORS) {
109 		handle_error(port);
110 		return 0;
111 	}
112 
113 	return serial_rx_fifo_level(port) ? 1 : 0;
114 }
115 
116 static int serial_getc_check(struct uart_port *port)
117 {
118 	unsigned short status;
119 
120 	status = sci_in(port, SCxSR);
121 
122 	if (status & SCIF_ERRORS)
123 		handle_error(port);
124 	if (sci_in(port, SCLSR) & SCxSR_ORER(port))
125 		handle_error(port);
126 	return status & (SCIF_DR | SCxSR_RDxF(port));
127 }
128 
129 static int sh_serial_getc_generic(struct uart_port *port)
130 {
131 	unsigned short status;
132 	char ch;
133 
134 	if (!serial_getc_check(port))
135 		return -EAGAIN;
136 
137 	ch = sci_in(port, SCxRDR);
138 	status = sci_in(port, SCxSR);
139 
140 	sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
141 
142 	if (status & SCIF_ERRORS)
143 		handle_error(port);
144 
145 	if (sci_in(port, SCLSR) & SCxSR_ORER(port))
146 		handle_error(port);
147 
148 	return ch;
149 }
150 
151 #if CONFIG_IS_ENABLED(DM_SERIAL)
152 
153 static int sh_serial_pending(struct udevice *dev, bool input)
154 {
155 	struct uart_port *priv = dev_get_priv(dev);
156 
157 	return sh_serial_tstc_generic(priv);
158 }
159 
160 static int sh_serial_putc(struct udevice *dev, const char ch)
161 {
162 	struct uart_port *priv = dev_get_priv(dev);
163 
164 	return serial_raw_putc(priv, ch);
165 }
166 
167 static int sh_serial_getc(struct udevice *dev)
168 {
169 	struct uart_port *priv = dev_get_priv(dev);
170 
171 	return sh_serial_getc_generic(priv);
172 }
173 
174 static int sh_serial_setbrg(struct udevice *dev, int baudrate)
175 {
176 	struct sh_serial_platdata *plat = dev_get_platdata(dev);
177 	struct uart_port *priv = dev_get_priv(dev);
178 
179 	sh_serial_setbrg_generic(priv, plat->clk, baudrate);
180 
181 	return 0;
182 }
183 
184 static int sh_serial_probe(struct udevice *dev)
185 {
186 	struct sh_serial_platdata *plat = dev_get_platdata(dev);
187 	struct uart_port *priv = dev_get_priv(dev);
188 
189 	priv->membase	= (unsigned char *)plat->base;
190 	priv->mapbase	= plat->base;
191 	priv->type	= plat->type;
192 	priv->clk_mode	= plat->clk_mode;
193 
194 	sh_serial_init_generic(priv);
195 
196 	return 0;
197 }
198 
199 static const struct dm_serial_ops sh_serial_ops = {
200 	.putc = sh_serial_putc,
201 	.pending = sh_serial_pending,
202 	.getc = sh_serial_getc,
203 	.setbrg = sh_serial_setbrg,
204 };
205 
206 #if CONFIG_IS_ENABLED(OF_CONTROL)
207 static const struct udevice_id sh_serial_id[] ={
208 	{.compatible = "renesas,sci", .data = PORT_SCI},
209 	{.compatible = "renesas,scif", .data = PORT_SCIF},
210 	{.compatible = "renesas,scifa", .data = PORT_SCIFA},
211 	{}
212 };
213 
214 static int sh_serial_ofdata_to_platdata(struct udevice *dev)
215 {
216 	struct sh_serial_platdata *plat = dev_get_platdata(dev);
217 	struct clk sh_serial_clk;
218 	fdt_addr_t addr;
219 	int ret;
220 
221 	addr = devfdt_get_addr(dev);
222 	if (!addr)
223 		return -EINVAL;
224 
225 	plat->base = addr;
226 
227 	ret = clk_get_by_name(dev, "fck", &sh_serial_clk);
228 	if (!ret) {
229 		ret = clk_enable(&sh_serial_clk);
230 		if (!ret)
231 			plat->clk = clk_get_rate(&sh_serial_clk);
232 	} else {
233 		plat->clk = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
234 					   "clock", 1);
235 	}
236 
237 	plat->type = dev_get_driver_data(dev);
238 	return 0;
239 }
240 #endif
241 
242 U_BOOT_DRIVER(serial_sh) = {
243 	.name	= "serial_sh",
244 	.id	= UCLASS_SERIAL,
245 	.of_match = of_match_ptr(sh_serial_id),
246 	.ofdata_to_platdata = of_match_ptr(sh_serial_ofdata_to_platdata),
247 	.platdata_auto_alloc_size = sizeof(struct sh_serial_platdata),
248 	.probe	= sh_serial_probe,
249 	.ops	= &sh_serial_ops,
250 	.flags	= DM_FLAG_PRE_RELOC,
251 	.priv_auto_alloc_size = sizeof(struct uart_port),
252 };
253 
254 #else /* CONFIG_DM_SERIAL */
255 
256 #if defined(CONFIG_CONS_SCIF0)
257 # define SCIF_BASE	SCIF0_BASE
258 #elif defined(CONFIG_CONS_SCIF1)
259 # define SCIF_BASE	SCIF1_BASE
260 #elif defined(CONFIG_CONS_SCIF2)
261 # define SCIF_BASE	SCIF2_BASE
262 #elif defined(CONFIG_CONS_SCIF3)
263 # define SCIF_BASE	SCIF3_BASE
264 #elif defined(CONFIG_CONS_SCIF4)
265 # define SCIF_BASE	SCIF4_BASE
266 #elif defined(CONFIG_CONS_SCIF5)
267 # define SCIF_BASE	SCIF5_BASE
268 #elif defined(CONFIG_CONS_SCIF6)
269 # define SCIF_BASE	SCIF6_BASE
270 #elif defined(CONFIG_CONS_SCIF7)
271 # define SCIF_BASE	SCIF7_BASE
272 #elif defined(CONFIG_CONS_SCIFA0)
273 # define SCIF_BASE	SCIFA0_BASE
274 #else
275 # error "Default SCIF doesn't set....."
276 #endif
277 
278 #if defined(CONFIG_SCIF_A)
279 	#define SCIF_BASE_PORT	PORT_SCIFA
280 #elif defined(CONFIG_SCI)
281 	#define SCIF_BASE_PORT  PORT_SCI
282 #else
283 	#define SCIF_BASE_PORT	PORT_SCIF
284 #endif
285 
286 static struct uart_port sh_sci = {
287 	.membase	= (unsigned char *)SCIF_BASE,
288 	.mapbase	= SCIF_BASE,
289 	.type		= SCIF_BASE_PORT,
290 #ifdef CONFIG_SCIF_USE_EXT_CLK
291 	.clk_mode =	EXT_CLK,
292 #endif
293 };
294 
295 static void sh_serial_setbrg(void)
296 {
297 	DECLARE_GLOBAL_DATA_PTR;
298 	struct uart_port *port = &sh_sci;
299 
300 	sh_serial_setbrg_generic(port, CONFIG_SH_SCIF_CLK_FREQ, gd->baudrate);
301 }
302 
303 static int sh_serial_init(void)
304 {
305 	struct uart_port *port = &sh_sci;
306 
307 	sh_serial_init_generic(port);
308 	serial_setbrg();
309 
310 	return 0;
311 }
312 
313 static void sh_serial_putc(const char c)
314 {
315 	struct uart_port *port = &sh_sci;
316 
317 	if (c == '\n') {
318 		while (1) {
319 			if  (serial_raw_putc(port, '\r') != -EAGAIN)
320 				break;
321 		}
322 	}
323 	while (1) {
324 		if  (serial_raw_putc(port, c) != -EAGAIN)
325 			break;
326 	}
327 }
328 
329 static int sh_serial_tstc(void)
330 {
331 	struct uart_port *port = &sh_sci;
332 
333 	return sh_serial_tstc_generic(port);
334 }
335 
336 static int sh_serial_getc(void)
337 {
338 	struct uart_port *port = &sh_sci;
339 	int ch;
340 
341 	while (1) {
342 		ch = sh_serial_getc_generic(port);
343 		if (ch != -EAGAIN)
344 			break;
345 	}
346 
347 	return ch;
348 }
349 
350 static struct serial_device sh_serial_drv = {
351 	.name	= "sh_serial",
352 	.start	= sh_serial_init,
353 	.stop	= NULL,
354 	.setbrg	= sh_serial_setbrg,
355 	.putc	= sh_serial_putc,
356 	.puts	= default_serial_puts,
357 	.getc	= sh_serial_getc,
358 	.tstc	= sh_serial_tstc,
359 };
360 
361 void sh_serial_initialize(void)
362 {
363 	serial_register(&sh_serial_drv);
364 }
365 
366 __weak struct serial_device *default_serial_console(void)
367 {
368 	return &sh_serial_drv;
369 }
370 #endif /* CONFIG_DM_SERIAL */
371