xref: /openbmc/u-boot/drivers/serial/serial_sh.c (revision 0093b3fc)
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 <clk.h>
13 #include <dm.h>
14 #include <asm/io.h>
15 #include <asm/processor.h>
16 #include <serial.h>
17 #include <linux/compiler.h>
18 #include <dm/platform_data/serial_sh.h>
19 #include "serial_sh.h"
20 
21 DECLARE_GLOBAL_DATA_PTR;
22 
23 #if defined(CONFIG_CPU_SH7760) || \
24 	defined(CONFIG_CPU_SH7780) || \
25 	defined(CONFIG_CPU_SH7785) || \
26 	defined(CONFIG_CPU_SH7786)
27 static int scif_rxfill(struct uart_port *port)
28 {
29 	return sci_in(port, SCRFDR) & 0xff;
30 }
31 #elif defined(CONFIG_CPU_SH7763)
32 static int scif_rxfill(struct uart_port *port)
33 {
34 	if ((port->mapbase == 0xffe00000) ||
35 	    (port->mapbase == 0xffe08000)) {
36 		/* SCIF0/1*/
37 		return sci_in(port, SCRFDR) & 0xff;
38 	} else {
39 		/* SCIF2 */
40 		return sci_in(port, SCFDR) & SCIF2_RFDC_MASK;
41 	}
42 }
43 #elif defined(CONFIG_ARCH_SH7372)
44 static int scif_rxfill(struct uart_port *port)
45 {
46 	if (port->type == PORT_SCIFA)
47 		return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
48 	else
49 		return sci_in(port, SCRFDR);
50 }
51 #else
52 static int scif_rxfill(struct uart_port *port)
53 {
54 	return sci_in(port, SCFDR) & SCIF_RFDC_MASK;
55 }
56 #endif
57 
58 static void sh_serial_init_generic(struct uart_port *port)
59 {
60 	sci_out(port, SCSCR , SCSCR_INIT(port));
61 	sci_out(port, SCSCR , SCSCR_INIT(port));
62 	sci_out(port, SCSMR, 0);
63 	sci_out(port, SCSMR, 0);
64 	sci_out(port, SCFCR, SCFCR_RFRST|SCFCR_TFRST);
65 	sci_in(port, SCFCR);
66 	sci_out(port, SCFCR, 0);
67 }
68 
69 static void
70 sh_serial_setbrg_generic(struct uart_port *port, int clk, int baudrate)
71 {
72 	if (port->clk_mode == EXT_CLK) {
73 		unsigned short dl = DL_VALUE(baudrate, clk);
74 		sci_out(port, DL, dl);
75 		/* Need wait: Clock * 1/dl * 1/16 */
76 		udelay((1000000 * dl * 16 / clk) * 1000 + 1);
77 	} else {
78 		sci_out(port, SCBRR, SCBRR_VALUE(baudrate, clk));
79 	}
80 }
81 
82 static void handle_error(struct uart_port *port)
83 {
84 	sci_in(port, SCxSR);
85 	sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
86 	sci_in(port, SCLSR);
87 	sci_out(port, SCLSR, 0x00);
88 }
89 
90 static int serial_raw_putc(struct uart_port *port, const char c)
91 {
92 	/* Tx fifo is empty */
93 	if (!(sci_in(port, SCxSR) & SCxSR_TEND(port)))
94 		return -EAGAIN;
95 
96 	sci_out(port, SCxTDR, c);
97 	sci_out(port, SCxSR, sci_in(port, SCxSR) & ~SCxSR_TEND(port));
98 
99 	return 0;
100 }
101 
102 static int serial_rx_fifo_level(struct uart_port *port)
103 {
104 	return scif_rxfill(port);
105 }
106 
107 static int sh_serial_tstc_generic(struct uart_port *port)
108 {
109 	if (sci_in(port, SCxSR) & SCIF_ERRORS) {
110 		handle_error(port);
111 		return 0;
112 	}
113 
114 	return serial_rx_fifo_level(port) ? 1 : 0;
115 }
116 
117 static int serial_getc_check(struct uart_port *port)
118 {
119 	unsigned short status;
120 
121 	status = sci_in(port, SCxSR);
122 
123 	if (status & SCIF_ERRORS)
124 		handle_error(port);
125 	if (sci_in(port, SCLSR) & SCxSR_ORER(port))
126 		handle_error(port);
127 	return status & (SCIF_DR | SCxSR_RDxF(port));
128 }
129 
130 static int sh_serial_getc_generic(struct uart_port *port)
131 {
132 	unsigned short status;
133 	char ch;
134 
135 	if (!serial_getc_check(port))
136 		return -EAGAIN;
137 
138 	ch = sci_in(port, SCxRDR);
139 	status = sci_in(port, SCxSR);
140 
141 	sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
142 
143 	if (status & SCIF_ERRORS)
144 		handle_error(port);
145 
146 	if (sci_in(port, SCLSR) & SCxSR_ORER(port))
147 		handle_error(port);
148 
149 	return ch;
150 }
151 
152 #ifdef CONFIG_DM_SERIAL
153 
154 static int sh_serial_pending(struct udevice *dev, bool input)
155 {
156 	struct uart_port *priv = dev_get_priv(dev);
157 
158 	return sh_serial_tstc_generic(priv);
159 }
160 
161 static int sh_serial_putc(struct udevice *dev, const char ch)
162 {
163 	struct uart_port *priv = dev_get_priv(dev);
164 
165 	return serial_raw_putc(priv, ch);
166 }
167 
168 static int sh_serial_getc(struct udevice *dev)
169 {
170 	struct uart_port *priv = dev_get_priv(dev);
171 
172 	return sh_serial_getc_generic(priv);
173 }
174 
175 static int sh_serial_setbrg(struct udevice *dev, int baudrate)
176 {
177 	struct sh_serial_platdata *plat = dev_get_platdata(dev);
178 	struct uart_port *priv = dev_get_priv(dev);
179 
180 	sh_serial_setbrg_generic(priv, plat->clk, baudrate);
181 
182 	return 0;
183 }
184 
185 static int sh_serial_probe(struct udevice *dev)
186 {
187 	struct sh_serial_platdata *plat = dev_get_platdata(dev);
188 	struct uart_port *priv = dev_get_priv(dev);
189 
190 	priv->membase	= (unsigned char *)plat->base;
191 	priv->mapbase	= plat->base;
192 	priv->type	= plat->type;
193 	priv->clk_mode	= plat->clk_mode;
194 
195 	sh_serial_init_generic(priv);
196 
197 	return 0;
198 }
199 
200 static const struct dm_serial_ops sh_serial_ops = {
201 	.putc = sh_serial_putc,
202 	.pending = sh_serial_pending,
203 	.getc = sh_serial_getc,
204 	.setbrg = sh_serial_setbrg,
205 };
206 
207 #ifdef CONFIG_OF_CONTROL
208 static const struct udevice_id sh_serial_id[] ={
209 	{.compatible = "renesas,sci", .data = PORT_SCI},
210 	{.compatible = "renesas,scif", .data = PORT_SCIF},
211 	{.compatible = "renesas,scifa", .data = PORT_SCIFA},
212 	{}
213 };
214 
215 static int sh_serial_ofdata_to_platdata(struct udevice *dev)
216 {
217 	struct sh_serial_platdata *plat = dev_get_platdata(dev);
218 	struct clk sh_serial_clk;
219 	fdt_addr_t addr;
220 	int ret;
221 
222 	addr = devfdt_get_addr(dev);
223 	if (!addr)
224 		return -EINVAL;
225 
226 	plat->base = addr;
227 
228 	ret = clk_get_by_name(dev, "fck", &sh_serial_clk);
229 	if (!ret) {
230 		ret = clk_enable(&sh_serial_clk);
231 		if (!ret)
232 			plat->clk = clk_get_rate(&sh_serial_clk);
233 	} else {
234 		plat->clk = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
235 					   "clock", 1);
236 	}
237 
238 	plat->type = dev_get_driver_data(dev);
239 	return 0;
240 }
241 #endif
242 
243 U_BOOT_DRIVER(serial_sh) = {
244 	.name	= "serial_sh",
245 	.id	= UCLASS_SERIAL,
246 	.of_match = of_match_ptr(sh_serial_id),
247 	.ofdata_to_platdata = of_match_ptr(sh_serial_ofdata_to_platdata),
248 	.platdata_auto_alloc_size = sizeof(struct sh_serial_platdata),
249 	.probe	= sh_serial_probe,
250 	.ops	= &sh_serial_ops,
251 	.flags	= DM_FLAG_PRE_RELOC,
252 	.priv_auto_alloc_size = sizeof(struct uart_port),
253 };
254 
255 #else /* CONFIG_DM_SERIAL */
256 
257 #if defined(CONFIG_CONS_SCIF0)
258 # define SCIF_BASE	SCIF0_BASE
259 #elif defined(CONFIG_CONS_SCIF1)
260 # define SCIF_BASE	SCIF1_BASE
261 #elif defined(CONFIG_CONS_SCIF2)
262 # define SCIF_BASE	SCIF2_BASE
263 #elif defined(CONFIG_CONS_SCIF3)
264 # define SCIF_BASE	SCIF3_BASE
265 #elif defined(CONFIG_CONS_SCIF4)
266 # define SCIF_BASE	SCIF4_BASE
267 #elif defined(CONFIG_CONS_SCIF5)
268 # define SCIF_BASE	SCIF5_BASE
269 #elif defined(CONFIG_CONS_SCIF6)
270 # define SCIF_BASE	SCIF6_BASE
271 #elif defined(CONFIG_CONS_SCIF7)
272 # define SCIF_BASE	SCIF7_BASE
273 #else
274 # error "Default SCIF doesn't set....."
275 #endif
276 
277 #if defined(CONFIG_SCIF_A)
278 	#define SCIF_BASE_PORT	PORT_SCIFA
279 #elif defined(CONFIG_SCI)
280 	#define SCIF_BASE_PORT  PORT_SCI
281 #else
282 	#define SCIF_BASE_PORT	PORT_SCIF
283 #endif
284 
285 static struct uart_port sh_sci = {
286 	.membase	= (unsigned char *)SCIF_BASE,
287 	.mapbase	= SCIF_BASE,
288 	.type		= SCIF_BASE_PORT,
289 #ifdef CONFIG_SCIF_USE_EXT_CLK
290 	.clk_mode =	EXT_CLK,
291 #endif
292 };
293 
294 static void sh_serial_setbrg(void)
295 {
296 	DECLARE_GLOBAL_DATA_PTR;
297 	struct uart_port *port = &sh_sci;
298 
299 	sh_serial_setbrg_generic(port, CONFIG_SH_SCIF_CLK_FREQ, gd->baudrate);
300 }
301 
302 static int sh_serial_init(void)
303 {
304 	struct uart_port *port = &sh_sci;
305 
306 	sh_serial_init_generic(port);
307 	serial_setbrg();
308 
309 	return 0;
310 }
311 
312 static void sh_serial_putc(const char c)
313 {
314 	struct uart_port *port = &sh_sci;
315 
316 	if (c == '\n') {
317 		while (1) {
318 			if  (serial_raw_putc(port, '\r') != -EAGAIN)
319 				break;
320 		}
321 	}
322 	while (1) {
323 		if  (serial_raw_putc(port, c) != -EAGAIN)
324 			break;
325 	}
326 }
327 
328 static int sh_serial_tstc(void)
329 {
330 	struct uart_port *port = &sh_sci;
331 
332 	return sh_serial_tstc_generic(port);
333 }
334 
335 static int sh_serial_getc(void)
336 {
337 	struct uart_port *port = &sh_sci;
338 	int ch;
339 
340 	while (1) {
341 		ch = sh_serial_getc_generic(port);
342 		if (ch != -EAGAIN)
343 			break;
344 	}
345 
346 	return ch;
347 }
348 
349 static struct serial_device sh_serial_drv = {
350 	.name	= "sh_serial",
351 	.start	= sh_serial_init,
352 	.stop	= NULL,
353 	.setbrg	= sh_serial_setbrg,
354 	.putc	= sh_serial_putc,
355 	.puts	= default_serial_puts,
356 	.getc	= sh_serial_getc,
357 	.tstc	= sh_serial_tstc,
358 };
359 
360 void sh_serial_initialize(void)
361 {
362 	serial_register(&sh_serial_drv);
363 }
364 
365 __weak struct serial_device *default_serial_console(void)
366 {
367 	return &sh_serial_drv;
368 }
369 #endif /* CONFIG_DM_SERIAL */
370