1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2022 Ruslan Bukin <br@bsdpad.com>
5 * Copyright (c) 2023 Arm Ltd
6 *
7 * This work was supported by Innovate UK project 105694, "Digital Security
8 * by Design (DSbD) Technology Platform Prototype".
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/cpu.h>
38 #include <sys/kernel.h>
39 #include <sys/module.h>
40
41 #include <dev/fdt/simplebus.h>
42 #include <dev/fdt/fdt_common.h>
43 #include <dev/ofw/ofw_bus_subr.h>
44
45 #include <dev/psci/smccc.h>
46
47 #include "scmi.h"
48 #include "scmi_protocols.h"
49 #include "scmi_shmem.h"
50
51 struct scmi_smc_softc {
52 struct scmi_softc base;
53 uint32_t smc_id;
54 device_t a2p_dev;
55 };
56
57 static int scmi_smc_transport_init(device_t);
58 static int scmi_smc_xfer_msg(device_t, struct scmi_msg *);
59 static int scmi_smc_poll_msg(device_t, struct scmi_msg *, unsigned int);
60 static int scmi_smc_collect_reply(device_t, struct scmi_msg *);
61 static void scmi_smc_tx_complete(device_t, void *);
62
63 static int scmi_smc_probe(device_t);
64
65 static int
scmi_smc_transport_init(device_t dev)66 scmi_smc_transport_init(device_t dev)
67 {
68 struct scmi_smc_softc *sc;
69 phandle_t node;
70 ssize_t len;
71
72 sc = device_get_softc(dev);
73
74 node = ofw_bus_get_node(dev);
75 len = OF_getencprop(node, "arm,smc-id", &sc->smc_id,
76 sizeof(sc->smc_id));
77 if (len <= 0) {
78 device_printf(dev, "No SMC ID found\n");
79 return (EINVAL);
80 }
81
82 device_printf(dev, "smc id %x\n", sc->smc_id);
83
84 sc->a2p_dev = scmi_shmem_get(dev, node, SCMI_CHAN_A2P);
85 if (sc->a2p_dev == NULL) {
86 device_printf(dev, "A2P shmem dev not found.\n");
87 return (ENXIO);
88 }
89
90 sc->base.trs_desc.no_completion_irq = true;
91 sc->base.trs_desc.reply_timo_ms = 30;
92
93 return (0);
94 }
95
96 static int
scmi_smc_xfer_msg(device_t dev,struct scmi_msg * msg)97 scmi_smc_xfer_msg(device_t dev, struct scmi_msg *msg)
98 {
99 struct scmi_smc_softc *sc;
100 int ret;
101
102 sc = device_get_softc(dev);
103
104 ret = scmi_shmem_prepare_msg(sc->a2p_dev, (uint8_t *)&msg->hdr,
105 msg->tx_len, msg->polling);
106 if (ret != 0)
107 return (ret);
108
109 arm_smccc_invoke_smc(sc->smc_id, NULL);
110
111 return (0);
112 }
113
114 static int
scmi_smc_poll_msg(device_t dev,struct scmi_msg * msg,unsigned int tmo)115 scmi_smc_poll_msg(device_t dev, struct scmi_msg *msg, unsigned int tmo)
116 {
117 struct scmi_smc_softc *sc;
118
119 sc = device_get_softc(dev);
120
121 /*
122 * Nothing to poll since commands are completed as soon as smc
123 * returns ... but did we get back what we were poling for ?
124 */
125 scmi_shmem_read_msg_header(sc->a2p_dev, &msg->hdr);
126
127 return (0);
128 }
129
130 static int
scmi_smc_collect_reply(device_t dev,struct scmi_msg * msg)131 scmi_smc_collect_reply(device_t dev, struct scmi_msg *msg)
132 {
133 struct scmi_smc_softc *sc;
134 int ret;
135
136 sc = device_get_softc(dev);
137
138 ret = scmi_shmem_read_msg_payload(sc->a2p_dev,
139 msg->payld, msg->rx_len - SCMI_MSG_HDR_SIZE);
140
141 return (ret);
142 }
143
144 static void
scmi_smc_tx_complete(device_t dev,void * chan)145 scmi_smc_tx_complete(device_t dev, void *chan)
146 {
147 struct scmi_smc_softc *sc;
148
149 sc = device_get_softc(dev);
150 scmi_shmem_tx_complete(sc->a2p_dev);
151 }
152
153 static int
scmi_smc_probe(device_t dev)154 scmi_smc_probe(device_t dev)
155 {
156
157 if (!ofw_bus_is_compatible(dev, "arm,scmi-smc"))
158 return (ENXIO);
159
160 if (!ofw_bus_status_okay(dev))
161 return (ENXIO);
162
163 device_set_desc(dev, "ARM SCMI SMC Transport driver");
164
165 return (BUS_PROBE_DEFAULT);
166 }
167
168 static device_method_t scmi_smc_methods[] = {
169 DEVMETHOD(device_probe, scmi_smc_probe),
170
171 /* SCMI interface */
172 DEVMETHOD(scmi_transport_init, scmi_smc_transport_init),
173 DEVMETHOD(scmi_xfer_msg, scmi_smc_xfer_msg),
174 DEVMETHOD(scmi_poll_msg, scmi_smc_poll_msg),
175 DEVMETHOD(scmi_collect_reply, scmi_smc_collect_reply),
176 DEVMETHOD(scmi_tx_complete, scmi_smc_tx_complete),
177
178 DEVMETHOD_END
179 };
180
181 DEFINE_CLASS_1(scmi_smc, scmi_smc_driver, scmi_smc_methods,
182 sizeof(struct scmi_smc_softc), scmi_driver);
183
184 /* Needs to be after the mmio_sram driver */
185 EARLY_DRIVER_MODULE(scmi_smc, simplebus, scmi_smc_driver, 0, 0,
186 BUS_PASS_SUPPORTDEV + BUS_PASS_ORDER_LATE);
187 MODULE_VERSION(scmi_smc, 1);
188