1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2014 Steven Lawrance <stl@koffein.net>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 /*
31 * Access to the Freescale i.MX6 On-Chip One-Time-Programmable Memory
32 */
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/bus.h>
39 #include <sys/rman.h>
40
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43
44 #include <machine/bus.h>
45
46 #include <arm/freescale/fsl_ocotpreg.h>
47 #include <arm/freescale/fsl_ocotpvar.h>
48
49 /*
50 * Find the physical address and size of the ocotp registers and devmap them,
51 * returning a pointer to the virtual address of the base.
52 *
53 * XXX This is temporary until we've worked out all the details of controlling
54 * the load order of devices. In an ideal world this device would be up and
55 * running before anything that needs it. When we're at a point to make that
56 * happen, this little block of code, and the few lines in fsl_ocotp_read_4()
57 * that refer to it can be deleted.
58 */
59 #include <vm/vm.h>
60 #include <vm/pmap.h>
61 #include <dev/fdt/fdt_common.h>
62
63 static uint32_t *ocotp_regs;
64 static vm_size_t ocotp_size;
65
66 static void
fsl_ocotp_devmap(void)67 fsl_ocotp_devmap(void)
68 {
69 phandle_t child, root;
70 u_long base, size;
71
72 if ((root = OF_finddevice("/")) == -1)
73 goto fatal;
74 if ((child = fdt_depth_search_compatible(root, "fsl,imx6q-ocotp", 0)) == 0)
75 goto fatal;
76 if (fdt_regsize(child, &base, &size) != 0)
77 goto fatal;
78
79 ocotp_size = (vm_size_t)size;
80
81 if ((ocotp_regs = pmap_mapdev((vm_paddr_t)base, ocotp_size)) == NULL)
82 goto fatal;
83
84 return;
85 fatal:
86 panic("cannot find/map the ocotp registers");
87 }
88 /* XXX end of temporary code */
89
90 struct ocotp_softc {
91 device_t dev;
92 struct resource *mem_res;
93 };
94
95 static struct ocotp_softc *ocotp_sc;
96
97 static inline uint32_t
RD4(struct ocotp_softc * sc,bus_size_t off)98 RD4(struct ocotp_softc *sc, bus_size_t off)
99 {
100
101 return (bus_read_4(sc->mem_res, off));
102 }
103
104 static int
ocotp_detach(device_t dev)105 ocotp_detach(device_t dev)
106 {
107
108 /* The ocotp registers are always accessible. */
109 return (EBUSY);
110 }
111
112 static int
ocotp_attach(device_t dev)113 ocotp_attach(device_t dev)
114 {
115 struct ocotp_softc *sc;
116 int err, rid;
117
118 sc = device_get_softc(dev);
119 sc->dev = dev;
120
121 /* Allocate bus_space resources. */
122 rid = 0;
123 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
124 RF_ACTIVE);
125 if (sc->mem_res == NULL) {
126 device_printf(dev, "Cannot allocate memory resources\n");
127 err = ENXIO;
128 goto out;
129 }
130
131 ocotp_sc = sc;
132
133 /* We're done with the temporary mapping now. */
134 if (ocotp_regs != NULL)
135 pmap_unmapdev(ocotp_regs, ocotp_size);
136
137 err = 0;
138
139 out:
140 if (err != 0)
141 ocotp_detach(dev);
142
143 return (err);
144 }
145
146 static int
ocotp_probe(device_t dev)147 ocotp_probe(device_t dev)
148 {
149
150 if (!ofw_bus_status_okay(dev))
151 return (ENXIO);
152
153 if (ofw_bus_is_compatible(dev, "fsl,imx6q-ocotp") == 0)
154 return (ENXIO);
155
156 device_set_desc(dev,
157 "Freescale On-Chip One-Time-Programmable Memory");
158
159 return (BUS_PROBE_DEFAULT);
160 }
161
162 uint32_t
fsl_ocotp_read_4(bus_size_t off)163 fsl_ocotp_read_4(bus_size_t off)
164 {
165
166 if (off > FSL_OCOTP_LAST_REG)
167 panic("fsl_ocotp_read_4: offset out of range");
168
169 /* If we have a softcontext use the regular bus_space read. */
170 if (ocotp_sc != NULL)
171 return (RD4(ocotp_sc, off));
172
173 /*
174 * Otherwise establish a tempory device mapping if necessary, and read
175 * the device without any help from bus_space.
176 *
177 * XXX Eventually the code from there down can be deleted.
178 */
179 if (ocotp_regs == NULL)
180 fsl_ocotp_devmap();
181
182 return (ocotp_regs[off / 4]);
183 }
184
185 static device_method_t ocotp_methods[] = {
186 /* Device interface */
187 DEVMETHOD(device_probe, ocotp_probe),
188 DEVMETHOD(device_attach, ocotp_attach),
189 DEVMETHOD(device_detach, ocotp_detach),
190
191 DEVMETHOD_END
192 };
193
194 static driver_t ocotp_driver = {
195 "ocotp",
196 ocotp_methods,
197 sizeof(struct ocotp_softc)
198 };
199
200 EARLY_DRIVER_MODULE(ocotp, simplebus, ocotp_driver, 0, 0,
201 BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
202