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 #include <sys/devmap.h>
63
64 static uint32_t *ocotp_regs;
65 static vm_size_t ocotp_size;
66
67 static void
fsl_ocotp_devmap(void)68 fsl_ocotp_devmap(void)
69 {
70 phandle_t child, root;
71 u_long base, size;
72
73 if ((root = OF_finddevice("/")) == -1)
74 goto fatal;
75 if ((child = fdt_depth_search_compatible(root, "fsl,imx6q-ocotp", 0)) == 0)
76 goto fatal;
77 if (fdt_regsize(child, &base, &size) != 0)
78 goto fatal;
79
80 ocotp_size = (vm_size_t)size;
81
82 if ((ocotp_regs = pmap_mapdev((vm_paddr_t)base, ocotp_size)) == NULL)
83 goto fatal;
84
85 return;
86 fatal:
87 panic("cannot find/map the ocotp registers");
88 }
89 /* XXX end of temporary code */
90
91 struct ocotp_softc {
92 device_t dev;
93 struct resource *mem_res;
94 };
95
96 static struct ocotp_softc *ocotp_sc;
97
98 static inline uint32_t
RD4(struct ocotp_softc * sc,bus_size_t off)99 RD4(struct ocotp_softc *sc, bus_size_t off)
100 {
101
102 return (bus_read_4(sc->mem_res, off));
103 }
104
105 static int
ocotp_detach(device_t dev)106 ocotp_detach(device_t dev)
107 {
108
109 /* The ocotp registers are always accessible. */
110 return (EBUSY);
111 }
112
113 static int
ocotp_attach(device_t dev)114 ocotp_attach(device_t dev)
115 {
116 struct ocotp_softc *sc;
117 int err, rid;
118
119 sc = device_get_softc(dev);
120 sc->dev = dev;
121
122 /* Allocate bus_space resources. */
123 rid = 0;
124 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
125 RF_ACTIVE);
126 if (sc->mem_res == NULL) {
127 device_printf(dev, "Cannot allocate memory resources\n");
128 err = ENXIO;
129 goto out;
130 }
131
132 ocotp_sc = sc;
133
134 /* We're done with the temporary mapping now. */
135 if (ocotp_regs != NULL)
136 pmap_unmapdev(ocotp_regs, ocotp_size);
137
138 err = 0;
139
140 out:
141 if (err != 0)
142 ocotp_detach(dev);
143
144 return (err);
145 }
146
147 static int
ocotp_probe(device_t dev)148 ocotp_probe(device_t dev)
149 {
150
151 if (!ofw_bus_status_okay(dev))
152 return (ENXIO);
153
154 if (ofw_bus_is_compatible(dev, "fsl,imx6q-ocotp") == 0)
155 return (ENXIO);
156
157 device_set_desc(dev,
158 "Freescale On-Chip One-Time-Programmable Memory");
159
160 return (BUS_PROBE_DEFAULT);
161 }
162
163 uint32_t
fsl_ocotp_read_4(bus_size_t off)164 fsl_ocotp_read_4(bus_size_t off)
165 {
166
167 if (off > FSL_OCOTP_LAST_REG)
168 panic("fsl_ocotp_read_4: offset out of range");
169
170 /* If we have a softcontext use the regular bus_space read. */
171 if (ocotp_sc != NULL)
172 return (RD4(ocotp_sc, off));
173
174 /*
175 * Otherwise establish a tempory device mapping if necessary, and read
176 * the device without any help from bus_space.
177 *
178 * XXX Eventually the code from there down can be deleted.
179 */
180 if (ocotp_regs == NULL)
181 fsl_ocotp_devmap();
182
183 return (ocotp_regs[off / 4]);
184 }
185
186 static device_method_t ocotp_methods[] = {
187 /* Device interface */
188 DEVMETHOD(device_probe, ocotp_probe),
189 DEVMETHOD(device_attach, ocotp_attach),
190 DEVMETHOD(device_detach, ocotp_detach),
191
192 DEVMETHOD_END
193 };
194
195 static driver_t ocotp_driver = {
196 "ocotp",
197 ocotp_methods,
198 sizeof(struct ocotp_softc)
199 };
200
201 EARLY_DRIVER_MODULE(ocotp, simplebus, ocotp_driver, 0, 0,
202 BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
203