xref: /freebsd/sys/dev/firmware/arm/scmi_shmem.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2022 Ruslan Bukin <br@bsdpad.com>
5  *
6  * This work was supported by Innovate UK project 105694, "Digital Security
7  * by Design (DSbD) Technology Platform Prototype".
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/cpu.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 
39 #include <dev/fdt/simplebus.h>
40 #include <dev/fdt/fdt_common.h>
41 #include <dev/ofw/ofw_bus_subr.h>
42 
43 #include "mmio_sram_if.h"
44 
45 #include "scmi.h"
46 
47 struct shmem_softc {
48 	device_t		dev;
49 	device_t		parent;
50 	int			reg;
51 };
52 
53 static int
54 shmem_probe(device_t dev)
55 {
56 
57 	if (!ofw_bus_is_compatible(dev, "arm,scmi-shmem"))
58 		return (ENXIO);
59 
60 	if (!ofw_bus_status_okay(dev))
61 		return (ENXIO);
62 
63 	device_set_desc(dev, "ARM SCMI Shared Memory driver");
64 
65 	return (BUS_PROBE_DEFAULT);
66 }
67 
68 static int
69 shmem_attach(device_t dev)
70 {
71 	struct shmem_softc *sc;
72 	phandle_t node;
73 	int reg;
74 
75 	sc = device_get_softc(dev);
76 	sc->dev = dev;
77 	sc->parent = device_get_parent(dev);
78 
79 	node = ofw_bus_get_node(dev);
80 	if (node == -1)
81 		return (ENXIO);
82 
83 	OF_getencprop(node, "reg", &reg, sizeof(reg));
84 
85 	dprintf("%s: reg %x\n", __func__, reg);
86 
87 	sc->reg = reg;
88 
89 	OF_device_register_xref(OF_xref_from_node(node), dev);
90 
91 	return (0);
92 }
93 
94 static int
95 shmem_detach(device_t dev)
96 {
97 
98 	return (0);
99 }
100 
101 void
102 scmi_shmem_read(device_t dev, bus_size_t offset, void *buf, bus_size_t len)
103 {
104 	struct shmem_softc *sc;
105 	uint8_t *addr;
106 	int i;
107 
108 	sc = device_get_softc(dev);
109 
110 	addr = (uint8_t *)buf;
111 
112 	for (i = 0; i < len; i++)
113 		addr[i] = MMIO_SRAM_READ_1(sc->parent, sc->reg + offset + i);
114 }
115 
116 void
117 scmi_shmem_write(device_t dev, bus_size_t offset, const void *buf,
118     bus_size_t len)
119 {
120 	struct shmem_softc *sc;
121 	const uint8_t *addr;
122 	int i;
123 
124 	sc = device_get_softc(dev);
125 
126 	addr = (const uint8_t *)buf;
127 
128 	for (i = 0; i < len; i++)
129 		MMIO_SRAM_WRITE_1(sc->parent, sc->reg + offset + i, addr[i]);
130 }
131 
132 static device_method_t shmem_methods[] = {
133 	DEVMETHOD(device_probe,		shmem_probe),
134 	DEVMETHOD(device_attach,	shmem_attach),
135 	DEVMETHOD(device_detach,	shmem_detach),
136 	DEVMETHOD_END
137 };
138 
139 DEFINE_CLASS_1(shmem, shmem_driver, shmem_methods, sizeof(struct shmem_softc),
140     simplebus_driver);
141 
142 EARLY_DRIVER_MODULE(shmem, mmio_sram, shmem_driver, 0, 0,
143     BUS_PASS_INTERRUPT + BUS_PASS_ORDER_MIDDLE);
144 MODULE_VERSION(scmi, 1);
145