xref: /freebsd/sys/dev/uart/uart_cpu_fdt.c (revision 76039bc84fae9915788b54ff28fe0cc4876952d2)
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 <vm/vm.h>
39 #include <vm/pmap.h>
40 
41 #include <machine/bus.h>
42 #include <machine/fdt.h>
43 
44 #include <dev/fdt/fdt_common.h>
45 #include <dev/ofw/ofw_bus.h>
46 #include <dev/ofw/ofw_bus_subr.h>
47 #include <dev/uart/uart.h>
48 #include <dev/uart/uart_bus.h>
49 #include <dev/uart/uart_cpu.h>
50 
51 /*
52  * UART console routines.
53  */
54 bus_space_tag_t uart_bus_space_io;
55 bus_space_tag_t uart_bus_space_mem;
56 
57 static int
58 uart_fdt_get_clock(phandle_t node, pcell_t *cell)
59 {
60 	pcell_t clock;
61 
62 	if ((OF_getprop(node, "clock-frequency", &clock,
63 	    sizeof(clock))) <= 0)
64 		return (ENXIO);
65 
66 	if (clock == 0)
67 		/* Try to retrieve parent 'bus-frequency' */
68 		/* XXX this should go to simple-bus fixup or so */
69 		if ((OF_getprop(OF_parent(node), "bus-frequency", &clock,
70 		    sizeof(clock))) <= 0)
71 			clock = 0;
72 
73 	*cell = fdt32_to_cpu(clock);
74 	return (0);
75 }
76 
77 static int
78 uart_fdt_get_shift(phandle_t node, pcell_t *cell)
79 {
80 	pcell_t shift;
81 
82 	if ((OF_getprop(node, "reg-shift", &shift, sizeof(shift))) <= 0)
83 		shift = 0;
84 	*cell = fdt32_to_cpu(shift);
85 	return (0);
86 }
87 
88 int
89 uart_cpu_eqres(struct uart_bas *b1, struct uart_bas *b2)
90 {
91 
92 	if (b1->bst != b2->bst)
93 		return (0);
94 	if (pmap_kextract(b1->bsh) == 0)
95 		return (0);
96 	if (pmap_kextract(b2->bsh) == 0)
97 		return (0);
98 	return ((pmap_kextract(b1->bsh) == pmap_kextract(b2->bsh)) ? 1 : 0);
99 }
100 
101 int
102 uart_cpu_getdev(int devtype, struct uart_devinfo *di)
103 {
104 	char buf[64];
105 	struct uart_class *class;
106 	phandle_t node, chosen;
107 	pcell_t shift, br, rclk;
108 	u_long start, size, pbase, psize;
109 	int err;
110 
111 	uart_bus_space_mem = fdtbus_bs_tag;
112 	uart_bus_space_io = NULL;
113 
114 	/* Allow overriding the FDT uning the environment. */
115 	class = &uart_ns8250_class;
116 	err = uart_getenv(devtype, di, class);
117 	if (!err)
118 		return (0);
119 
120 	if (devtype != UART_DEV_CONSOLE)
121 		return (ENXIO);
122 
123 	/*
124 	 * Retrieve /chosen/std{in,out}.
125 	 */
126 	if ((chosen = OF_finddevice("/chosen")) == -1)
127 		return (ENXIO);
128 	if (OF_getprop(chosen, "stdin", buf, sizeof(buf)) <= 0)
129 		return (ENXIO);
130 	if ((node = OF_finddevice(buf)) == -1)
131 		return (ENXIO);
132 	if (OF_getprop(chosen, "stdout", buf, sizeof(buf)) <= 0)
133 		return (ENXIO);
134 	if (OF_finddevice(buf) != node)
135 		/* Only stdin == stdout is supported. */
136 		return (ENXIO);
137 	/*
138 	 * Retrieve serial attributes.
139 	 */
140 	uart_fdt_get_shift(node, &shift);
141 
142 	if (OF_getprop(node, "current-speed", &br, sizeof(br)) <= 0)
143 		br = 0;
144 	br = fdt32_to_cpu(br);
145 
146 	if ((err = uart_fdt_get_clock(node, &rclk)) != 0)
147 		return (err);
148 	/*
149 	 * Finalize configuration.
150 	 */
151 	if (fdt_is_compatible(node, "fsl,imx-uart"))
152 		class = &uart_imx_class;
153 	else if (fdt_is_compatible(node, "quicc"))
154 		class = &uart_quicc_class;
155 	else if (fdt_is_compatible(node, "lpc"))
156 		class = &uart_lpc_class;
157 	else if (fdt_is_compatible(node, "arm,pl011"))
158 		class = &uart_pl011_class;
159 	else if (fdt_is_compatible(node, "exynos"))
160 		class = &uart_s3c2410_class;
161 	else if (fdt_is_compatible(node, "cadence,uart"))
162 		class = &uart_cdnc_class;
163 	else if (fdt_is_compatible(node, "ti,ns16550"))
164 		class = &uart_ti8250_class;
165 	else if (fdt_is_compatible(node, "ns16550"))
166 		class = &uart_ns8250_class;
167 
168 	di->bas.chan = 0;
169 	di->bas.regshft = (u_int)shift;
170 	di->baudrate = br;
171 	di->bas.rclk = (u_int)rclk;
172 	di->ops = uart_getops(class);
173 	di->databits = 8;
174 	di->stopbits = 1;
175 	di->parity = UART_PARITY_NONE;
176 	di->bas.bst = uart_bus_space_mem;
177 
178 	err = fdt_regsize(node, &start, &size);
179 	if (err)
180 		return (ENXIO);
181 	err = fdt_get_range(OF_parent(node), 0, &pbase, &psize);
182 	if (err)
183 		pbase = 0;
184 
185 	start += pbase;
186 
187 	return (bus_space_map(di->bas.bst, start, size, 0, &di->bas.bsh));
188 }
189