xref: /openbmc/u-boot/drivers/serial/serial_sh.c (revision 44da3a17)
1 /*
2  * SuperH SCIF device driver.
3  * Copyright (C) 2013  Renesas Electronics Corporation
4  * Copyright (C) 2007,2008,2010, 2014 Nobuhiro Iwamatsu
5  * Copyright (C) 2002 - 2008  Paul Mundt
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #include <common.h>
11 #include <errno.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 #if defined(CONFIG_CPU_SH7760) || \
21 	defined(CONFIG_CPU_SH7780) || \
22 	defined(CONFIG_CPU_SH7785) || \
23 	defined(CONFIG_CPU_SH7786)
24 static int scif_rxfill(struct uart_port *port)
25 {
26 	return sci_in(port, SCRFDR) & 0xff;
27 }
28 #elif defined(CONFIG_CPU_SH7763)
29 static int scif_rxfill(struct uart_port *port)
30 {
31 	if ((port->mapbase == 0xffe00000) ||
32 	    (port->mapbase == 0xffe08000)) {
33 		/* SCIF0/1*/
34 		return sci_in(port, SCRFDR) & 0xff;
35 	} else {
36 		/* SCIF2 */
37 		return sci_in(port, SCFDR) & SCIF2_RFDC_MASK;
38 	}
39 }
40 #elif defined(CONFIG_ARCH_SH7372)
41 static int scif_rxfill(struct uart_port *port)
42 {
43 	if (port->type == PORT_SCIFA)
44 		return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
45 	else
46 		return sci_in(port, SCRFDR);
47 }
48 #else
49 static int scif_rxfill(struct uart_port *port)
50 {
51 	return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
52 }
53 #endif
54 
55 static void sh_serial_init_generic(struct uart_port *port)
56 {
57 	sci_out(port, SCSCR , SCSCR_INIT(port));
58 	sci_out(port, SCSCR , SCSCR_INIT(port));
59 	sci_out(port, SCSMR, 0);
60 	sci_out(port, SCSMR, 0);
61 	sci_out(port, SCFCR, SCFCR_RFRST|SCFCR_TFRST);
62 	sci_in(port, SCFCR);
63 	sci_out(port, SCFCR, 0);
64 }
65 
66 static void
67 sh_serial_setbrg_generic(struct uart_port *port, int clk, int baudrate)
68 {
69 	if (port->clk_mode == EXT_CLK) {
70 		unsigned short dl = DL_VALUE(baudrate, clk);
71 		sci_out(port, DL, dl);
72 		/* Need wait: Clock * 1/dl * 1/16 */
73 		udelay((1000000 * dl * 16 / clk) * 1000 + 1);
74 	} else {
75 		sci_out(port, SCBRR, SCBRR_VALUE(baudrate, clk));
76 	}
77 }
78 
79 static void handle_error(struct uart_port *port)
80 {
81 	sci_in(port, SCxSR);
82 	sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
83 	sci_in(port, SCLSR);
84 	sci_out(port, SCLSR, 0x00);
85 }
86 
87 static int serial_raw_putc(struct uart_port *port, const char c)
88 {
89 	/* Tx fifo is empty */
90 	if (!(sci_in(port, SCxSR) & SCxSR_TEND(port)))
91 		return -EAGAIN;
92 
93 	sci_out(port, SCxTDR, c);
94 	sci_out(port, SCxSR, sci_in(port, SCxSR) & ~SCxSR_TEND(port));
95 
96 	return 0;
97 }
98 
99 static int serial_rx_fifo_level(struct uart_port *port)
100 {
101 	return scif_rxfill(port);
102 }
103 
104 static int sh_serial_tstc_generic(struct uart_port *port)
105 {
106 	if (sci_in(port, SCxSR) & SCIF_ERRORS) {
107 		handle_error(port);
108 		return 0;
109 	}
110 
111 	return serial_rx_fifo_level(port) ? 1 : 0;
112 }
113 
114 static int serial_getc_check(struct uart_port *port)
115 {
116 	unsigned short status;
117 
118 	status = sci_in(port, SCxSR);
119 
120 	if (status & SCIF_ERRORS)
121 		handle_error(port);
122 	if (sci_in(port, SCLSR) & SCxSR_ORER(port))
123 		handle_error(port);
124 	return status & (SCIF_DR | SCxSR_RDxF(port));
125 }
126 
127 static int sh_serial_getc_generic(struct uart_port *port)
128 {
129 	unsigned short status;
130 	char ch;
131 
132 	if (!serial_getc_check(port))
133 		return -EAGAIN;
134 
135 	ch = sci_in(port, SCxRDR);
136 	status = sci_in(port, SCxSR);
137 
138 	sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
139 
140 	if (status & SCIF_ERRORS)
141 		handle_error(port);
142 
143 	if (sci_in(port, SCLSR) & SCxSR_ORER(port))
144 		handle_error(port);
145 
146 	return ch;
147 }
148 
149 #ifdef CONFIG_DM_SERIAL
150 
151 static int sh_serial_pending(struct udevice *dev, bool input)
152 {
153 	struct uart_port *priv = dev_get_priv(dev);
154 
155 	return sh_serial_tstc_generic(priv);
156 }
157 
158 static int sh_serial_putc(struct udevice *dev, const char ch)
159 {
160 	struct uart_port *priv = dev_get_priv(dev);
161 
162 	return serial_raw_putc(priv, ch);
163 }
164 
165 static int sh_serial_getc(struct udevice *dev)
166 {
167 	struct uart_port *priv = dev_get_priv(dev);
168 
169 	return sh_serial_getc_generic(priv);
170 }
171 
172 static int sh_serial_setbrg(struct udevice *dev, int baudrate)
173 {
174 	struct sh_serial_platdata *plat = dev_get_platdata(dev);
175 	struct uart_port *priv = dev_get_priv(dev);
176 
177 	sh_serial_setbrg_generic(priv, plat->clk, baudrate);
178 
179 	return 0;
180 }
181 
182 static int sh_serial_probe(struct udevice *dev)
183 {
184 	struct sh_serial_platdata *plat = dev_get_platdata(dev);
185 	struct uart_port *priv = dev_get_priv(dev);
186 
187 	priv->membase	= (unsigned char *)plat->base;
188 	priv->mapbase	= plat->base;
189 	priv->type	= plat->type;
190 	priv->clk_mode	= plat->clk_mode;
191 
192 	sh_serial_init_generic(priv);
193 
194 	return 0;
195 }
196 
197 static const struct dm_serial_ops sh_serial_ops = {
198 	.putc = sh_serial_putc,
199 	.pending = sh_serial_pending,
200 	.getc = sh_serial_getc,
201 	.setbrg = sh_serial_setbrg,
202 };
203 
204 U_BOOT_DRIVER(serial_sh) = {
205 	.name	= "serial_sh",
206 	.id	= UCLASS_SERIAL,
207 	.probe	= sh_serial_probe,
208 	.ops	= &sh_serial_ops,
209 	.flags	= DM_FLAG_PRE_RELOC,
210 	.priv_auto_alloc_size = sizeof(struct uart_port),
211 };
212 
213 #else /* CONFIG_DM_SERIAL */
214 
215 #if defined(CONFIG_CONS_SCIF0)
216 # define SCIF_BASE	SCIF0_BASE
217 #elif defined(CONFIG_CONS_SCIF1)
218 # define SCIF_BASE	SCIF1_BASE
219 #elif defined(CONFIG_CONS_SCIF2)
220 # define SCIF_BASE	SCIF2_BASE
221 #elif defined(CONFIG_CONS_SCIF3)
222 # define SCIF_BASE	SCIF3_BASE
223 #elif defined(CONFIG_CONS_SCIF4)
224 # define SCIF_BASE	SCIF4_BASE
225 #elif defined(CONFIG_CONS_SCIF5)
226 # define SCIF_BASE	SCIF5_BASE
227 #elif defined(CONFIG_CONS_SCIF6)
228 # define SCIF_BASE	SCIF6_BASE
229 #elif defined(CONFIG_CONS_SCIF7)
230 # define SCIF_BASE	SCIF7_BASE
231 #else
232 # error "Default SCIF doesn't set....."
233 #endif
234 
235 #if defined(CONFIG_SCIF_A)
236 	#define SCIF_BASE_PORT	PORT_SCIFA
237 #else
238 	#define SCIF_BASE_PORT	PORT_SCIF
239 #endif
240 
241 static struct uart_port sh_sci = {
242 	.membase	= (unsigned char *)SCIF_BASE,
243 	.mapbase	= SCIF_BASE,
244 	.type		= SCIF_BASE_PORT,
245 #ifdef CONFIG_SCIF_USE_EXT_CLK
246 	.clk_mode =	EXT_CLK,
247 #endif
248 };
249 
250 static void sh_serial_setbrg(void)
251 {
252 	DECLARE_GLOBAL_DATA_PTR;
253 	struct uart_port *port = &sh_sci;
254 
255 	sh_serial_setbrg_generic(port, CONFIG_SH_SCIF_CLK_FREQ, gd->baudrate);
256 }
257 
258 static int sh_serial_init(void)
259 {
260 	struct uart_port *port = &sh_sci;
261 
262 	sh_serial_init_generic(port);
263 	serial_setbrg();
264 
265 	return 0;
266 }
267 
268 static void sh_serial_putc(const char c)
269 {
270 	struct uart_port *port = &sh_sci;
271 
272 	if (c == '\n') {
273 		while (1) {
274 			if  (serial_raw_putc(port, '\r') != -EAGAIN)
275 				break;
276 		}
277 	}
278 	while (1) {
279 		if  (serial_raw_putc(port, c) != -EAGAIN)
280 			break;
281 	}
282 }
283 
284 static int sh_serial_tstc(void)
285 {
286 	struct uart_port *port = &sh_sci;
287 
288 	return sh_serial_tstc_generic(port);
289 }
290 
291 static int sh_serial_getc(void)
292 {
293 	struct uart_port *port = &sh_sci;
294 	int ch;
295 
296 	while (1) {
297 		ch = sh_serial_getc_generic(port);
298 		if (ch != -EAGAIN)
299 			break;
300 	}
301 
302 	return ch;
303 }
304 
305 static struct serial_device sh_serial_drv = {
306 	.name	= "sh_serial",
307 	.start	= sh_serial_init,
308 	.stop	= NULL,
309 	.setbrg	= sh_serial_setbrg,
310 	.putc	= sh_serial_putc,
311 	.puts	= default_serial_puts,
312 	.getc	= sh_serial_getc,
313 	.tstc	= sh_serial_tstc,
314 };
315 
316 void sh_serial_initialize(void)
317 {
318 	serial_register(&sh_serial_drv);
319 }
320 
321 __weak struct serial_device *default_serial_console(void)
322 {
323 	return &sh_serial_drv;
324 }
325 #endif /* CONFIG_DM_SERIAL */
326