xref: /freebsd/sys/dev/uart/uart_cpu_fdt.c (revision 74036c4de983981ee2b23f91e285363293aa7c3c)
1 /*-
2  * Copyright (c) 2009-2010 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Semihalf under sponsorship from
6  * the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/bus.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 
38 #include <machine/bus.h>
39 #include <machine/fdt.h>
40 
41 #include <dev/fdt/fdt_common.h>
42 #include <dev/ofw/ofw_bus.h>
43 #include <dev/ofw/ofw_bus_subr.h>
44 #include <dev/uart/uart.h>
45 #include <dev/uart/uart_bus.h>
46 #include <dev/uart/uart_cpu.h>
47 
48 /*
49  * UART console routines.
50  */
51 bus_space_tag_t uart_bus_space_io;
52 bus_space_tag_t uart_bus_space_mem;
53 
54 static int
55 uart_fdt_get_clock(phandle_t node, pcell_t *cell)
56 {
57 	pcell_t clock;
58 
59 	if ((OF_getprop(node, "clock-frequency", &clock,
60 	    sizeof(clock))) <= 0)
61 		return (ENXIO);
62 
63 	if (clock == 0)
64 		/* Try to retrieve parent 'bus-frequency' */
65 		/* XXX this should go to simple-bus fixup or so */
66 		if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
67 		    sizeof(clock))) <= 0)
68 			clock = 0;
69 
70 	*cell = fdt32_to_cpu(clock);
71 	return (0);
72 }
73 
74 static int
75 uart_fdt_get_shift(phandle_t node, pcell_t *cell)
76 {
77 	pcell_t shift;
78 
79 	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
80 		shift = 0;
81 	*cell = fdt32_to_cpu(shift);
82 	return (0);
83 }
84 
85 int
86 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
87 {
88 
89 	return ((b1->bsh == b2->bsh && b1->bst == b2->bst) ? 1 : 0);
90 }
91 
92 int
93 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
94 {
95 	char buf[64];
96 	struct uart_class *class;
97 	phandle_t node, chosen;
98 	pcell_t shift, br, rclk;
99 	u_long start, size, pbase, psize;
100 	int err;
101 
102 	uart_bus_space_mem = fdtbus_bs_tag;
103 	uart_bus_space_io = NULL;
104 
105 	/* Allow overriding the FDT uning the environment. */
106 	class = &uart_ns8250_class;
107 	err = uart_getenv(devtype, di, class);
108 	if (!err)
109 		return (0);
110 
111 	if (devtype != UART_DEV_CONSOLE)
112 		return (ENXIO);
113 
114 	/*
115 	 * Retrieve /chosen/std{in,out}.
116 	 */
117 	if ((chosen = OF_finddevice("/chosen")) == -1)
118 		return (ENXIO);
119 	if (OF_getprop(chosen, "stdin", buf, sizeof(buf)) <= 0)
120 		return (ENXIO);
121 	if ((node = OF_finddevice(buf)) == -1)
122 		return (ENXIO);
123 	if (OF_getprop(chosen, "stdout", buf, sizeof(buf)) <= 0)
124 		return (ENXIO);
125 	if (OF_finddevice(buf) != node)
126 		/* Only stdin == stdout is supported. */
127 		return (ENXIO);
128 	/*
129 	 * Retrieve serial attributes.
130 	 */
131 	uart_fdt_get_shift(node, &shift);
132 
133 	if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
134 		br = 0;
135 	br = fdt32_to_cpu(br);
136 
137 	if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
138 		return (err);
139 	/*
140 	 * Finalize configuration.
141 	 */
142 	if (fdt_is_compatible(node, "fsl,imx-uart"))
143 		class = &uart_imx_class;
144 	if (fdt_is_compatible(node, "quicc"))
145 		class = &uart_quicc_class;
146 	if (fdt_is_compatible(node, "lpc"))
147 		class = &uart_lpc_class;
148 	if (fdt_is_compatible(node, "ns16550"))
149 		class = &uart_ns8250_class;
150 	if (fdt_is_compatible(node, "arm,pl011"))
151 		class = &uart_pl011_class;
152 	if (fdt_is_compatible(node, "cadence,uart"))
153 		class = &uart_cdnc_class;
154 
155 	di->bas.chan = 0;
156 	di->bas.regshft = (u_int)shift;
157 	di->baudrate = br;
158 	di->bas.rclk = (u_int)rclk;
159 	di->ops = uart_getops(class);
160 	di->databits = 8;
161 	di->stopbits = 1;
162 	di->parity = UART_PARITY_NONE;
163 	di->bas.bst = uart_bus_space_mem;
164 
165 	err = fdt_regsize(node, &start, &size);
166 	if (err)
167 		return (ENXIO);
168 	err = fdt_get_range(OF_parent(node), 0, &pbase, &psize);
169 	if (err)
170 		pbase = 0;
171 
172 	start += pbase;
173 
174 	return (bus_space_map(di->bas.bst, start, size, 0, &di->bas.bsh));
175 }
176