1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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__FBSDID("$FreeBSD$");
31
32/*
33 * Access to the Freescale i.MX6 On-Chip One-Time-Programmable Memory
34 */
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/kernel.h>
39#include <sys/module.h>
40#include <sys/bus.h>
41#include <sys/rman.h>
42
43#include <dev/ofw/ofw_bus.h>
44#include <dev/ofw/ofw_bus_subr.h>
45
46#include <machine/bus.h>
47
48#include <arm/freescale/fsl_ocotpreg.h>
49#include <arm/freescale/fsl_ocotpvar.h>
50
51/*
52 * Find the physical address and size of the ocotp registers and devmap them,
53 * returning a pointer to the virtual address of the base.
54 *
55 * XXX This is temporary until we've worked out all the details of controlling
56 * the load order of devices.  In an ideal world this device would be up and
57 * running before anything that needs it.  When we're at a point to make that
58 * happen, this little block of code, and the few lines in fsl_ocotp_read_4()
59 * that refer to it can be deleted.
60 */
61#include <vm/vm.h>
62#include <vm/pmap.h>
63#include <dev/fdt/fdt_common.h>
64#include <sys/devmap.h>
65
66static uint32_t   *ocotp_regs;
67static vm_size_t   ocotp_size;
68
69static void
70fsl_ocotp_devmap(void)
71{
72	phandle_t child, root;
73	u_long base, size;
74
75	if ((root = OF_finddevice("/")) == -1)
76		goto fatal;
77	if ((child = fdt_depth_search_compatible(root, "fsl,imx6q-ocotp", 0)) == 0)
78		goto fatal;
79	if (fdt_regsize(child, &base, &size) != 0)
80		goto fatal;
81
82	ocotp_size = (vm_size_t)size;
83
84	if ((ocotp_regs = pmap_mapdev((vm_offset_t)base, ocotp_size)) == NULL)
85		goto fatal;
86
87	return;
88fatal:
89	panic("cannot find/map the ocotp registers");
90}
91/* XXX end of temporary code */
92
93struct ocotp_softc {
94	device_t	dev;
95	struct resource	*mem_res;
96};
97
98static struct ocotp_softc *ocotp_sc;
99
100static inline uint32_t
101RD4(struct ocotp_softc *sc, bus_size_t off)
102{
103
104	return (bus_read_4(sc->mem_res, off));
105}
106
107static int
108ocotp_detach(device_t dev)
109{
110
111	/* The ocotp registers are always accessible. */
112	return (EBUSY);
113}
114
115static int
116ocotp_attach(device_t dev)
117{
118	struct ocotp_softc *sc;
119	int err, rid;
120
121	sc = device_get_softc(dev);
122	sc->dev = dev;
123
124	/* Allocate bus_space resources. */
125	rid = 0;
126	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
127	    RF_ACTIVE);
128	if (sc->mem_res == NULL) {
129		device_printf(dev, "Cannot allocate memory resources\n");
130		err = ENXIO;
131		goto out;
132	}
133
134	ocotp_sc = sc;
135
136	/* We're done with the temporary mapping now. */
137	if (ocotp_regs != NULL)
138		pmap_unmapdev((vm_offset_t)ocotp_regs, ocotp_size);
139
140	err = 0;
141
142out:
143	if (err != 0)
144		ocotp_detach(dev);
145
146	return (err);
147}
148
149static int
150ocotp_probe(device_t dev)
151{
152
153	if (!ofw_bus_status_okay(dev))
154		return (ENXIO);
155
156	if (ofw_bus_is_compatible(dev, "fsl,imx6q-ocotp") == 0)
157		return (ENXIO);
158
159	device_set_desc(dev,
160	    "Freescale On-Chip One-Time-Programmable Memory");
161
162	return (BUS_PROBE_DEFAULT);
163}
164
165uint32_t
166fsl_ocotp_read_4(bus_size_t off)
167{
168
169	if (off > FSL_OCOTP_LAST_REG)
170		panic("fsl_ocotp_read_4: offset out of range");
171
172	/* If we have a softcontext use the regular bus_space read. */
173	if (ocotp_sc != NULL)
174		return (RD4(ocotp_sc, off));
175
176	/*
177	 * Otherwise establish a tempory device mapping if necessary, and read
178	 * the device without any help from bus_space.
179	 *
180	 * XXX Eventually the code from there down can be deleted.
181	 */
182	if (ocotp_regs == NULL)
183		fsl_ocotp_devmap();
184
185	return (ocotp_regs[off / 4]);
186}
187
188static device_method_t ocotp_methods[] = {
189	/* Device interface */
190	DEVMETHOD(device_probe,  ocotp_probe),
191	DEVMETHOD(device_attach, ocotp_attach),
192	DEVMETHOD(device_detach, ocotp_detach),
193
194	DEVMETHOD_END
195};
196
197static driver_t ocotp_driver = {
198	"ocotp",
199	ocotp_methods,
200	sizeof(struct ocotp_softc)
201};
202
203static devclass_t ocotp_devclass;
204
205EARLY_DRIVER_MODULE(ocotp, simplebus, ocotp_driver, ocotp_devclass, 0, 0,
206    BUS_PASS_CPU + BUS_PASS_ORDER_FIRST);
207
208