xref: /openbmc/u-boot/drivers/serial/serial_sh.c (revision 3991f42e)
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 = fdtdec_get_addr(gd->fdt_blob, dev_of_offset(dev), "reg");
223 	if (addr == FDT_ADDR_T_NONE)
224 		return -EINVAL;
225 
226 	plat->base = addr;
227 
228 	ret = clk_get_by_name(dev, "fck", &sh_serial_clk);
229 	if (!ret)
230 		plat->clk = clk_get_rate(&sh_serial_clk);
231 	else
232 		plat->clk = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
233 					   "clock", 1);
234 
235 	plat->type = dev_get_driver_data(dev);
236 	return 0;
237 }
238 #endif
239 
240 U_BOOT_DRIVER(serial_sh) = {
241 	.name	= "serial_sh",
242 	.id	= UCLASS_SERIAL,
243 	.of_match = of_match_ptr(sh_serial_id),
244 	.ofdata_to_platdata = of_match_ptr(sh_serial_ofdata_to_platdata),
245 	.platdata_auto_alloc_size = sizeof(struct sh_serial_platdata),
246 	.probe	= sh_serial_probe,
247 	.ops	= &sh_serial_ops,
248 	.flags	= DM_FLAG_PRE_RELOC,
249 	.priv_auto_alloc_size = sizeof(struct uart_port),
250 };
251 
252 #else /* CONFIG_DM_SERIAL */
253 
254 #if defined(CONFIG_CONS_SCIF0)
255 # define SCIF_BASE	SCIF0_BASE
256 #elif defined(CONFIG_CONS_SCIF1)
257 # define SCIF_BASE	SCIF1_BASE
258 #elif defined(CONFIG_CONS_SCIF2)
259 # define SCIF_BASE	SCIF2_BASE
260 #elif defined(CONFIG_CONS_SCIF3)
261 # define SCIF_BASE	SCIF3_BASE
262 #elif defined(CONFIG_CONS_SCIF4)
263 # define SCIF_BASE	SCIF4_BASE
264 #elif defined(CONFIG_CONS_SCIF5)
265 # define SCIF_BASE	SCIF5_BASE
266 #elif defined(CONFIG_CONS_SCIF6)
267 # define SCIF_BASE	SCIF6_BASE
268 #elif defined(CONFIG_CONS_SCIF7)
269 # define SCIF_BASE	SCIF7_BASE
270 #else
271 # error "Default SCIF doesn't set....."
272 #endif
273 
274 #if defined(CONFIG_SCIF_A)
275 	#define SCIF_BASE_PORT	PORT_SCIFA
276 #elif defined(CONFIG_SCI)
277 	#define SCIF_BASE_PORT  PORT_SCI
278 #else
279 	#define SCIF_BASE_PORT	PORT_SCIF
280 #endif
281 
282 static struct uart_port sh_sci = {
283 	.membase	= (unsigned char *)SCIF_BASE,
284 	.mapbase	= SCIF_BASE,
285 	.type		= SCIF_BASE_PORT,
286 #ifdef CONFIG_SCIF_USE_EXT_CLK
287 	.clk_mode =	EXT_CLK,
288 #endif
289 };
290 
291 static void sh_serial_setbrg(void)
292 {
293 	DECLARE_GLOBAL_DATA_PTR;
294 	struct uart_port *port = &sh_sci;
295 
296 	sh_serial_setbrg_generic(port, CONFIG_SH_SCIF_CLK_FREQ, gd->baudrate);
297 }
298 
299 static int sh_serial_init(void)
300 {
301 	struct uart_port *port = &sh_sci;
302 
303 	sh_serial_init_generic(port);
304 	serial_setbrg();
305 
306 	return 0;
307 }
308 
309 static void sh_serial_putc(const char c)
310 {
311 	struct uart_port *port = &sh_sci;
312 
313 	if (c == '\n') {
314 		while (1) {
315 			if  (serial_raw_putc(port, '\r') != -EAGAIN)
316 				break;
317 		}
318 	}
319 	while (1) {
320 		if  (serial_raw_putc(port, c) != -EAGAIN)
321 			break;
322 	}
323 }
324 
325 static int sh_serial_tstc(void)
326 {
327 	struct uart_port *port = &sh_sci;
328 
329 	return sh_serial_tstc_generic(port);
330 }
331 
332 static int sh_serial_getc(void)
333 {
334 	struct uart_port *port = &sh_sci;
335 	int ch;
336 
337 	while (1) {
338 		ch = sh_serial_getc_generic(port);
339 		if (ch != -EAGAIN)
340 			break;
341 	}
342 
343 	return ch;
344 }
345 
346 static struct serial_device sh_serial_drv = {
347 	.name	= "sh_serial",
348 	.start	= sh_serial_init,
349 	.stop	= NULL,
350 	.setbrg	= sh_serial_setbrg,
351 	.putc	= sh_serial_putc,
352 	.puts	= default_serial_puts,
353 	.getc	= sh_serial_getc,
354 	.tstc	= sh_serial_tstc,
355 };
356 
357 void sh_serial_initialize(void)
358 {
359 	serial_register(&sh_serial_drv);
360 }
361 
362 __weak struct serial_device *default_serial_console(void)
363 {
364 	return &sh_serial_drv;
365 }
366 #endif /* CONFIG_DM_SERIAL */
367