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/mailbox/arm/arm_doorbell.h"
46
47 #include "scmi.h"
48 #include "scmi_protocols.h"
49 #include "scmi_shmem.h"
50
51 #define SCMI_MBOX_POLL_INTERVAL_MS 3
52
53 struct scmi_mailbox_softc {
54 struct scmi_softc base;
55 device_t a2p_dev;
56 struct arm_doorbell *db;
57 };
58
59 static int scmi_mailbox_transport_init(device_t);
60 static void scmi_mailbox_transport_cleanup(device_t);
61 static int scmi_mailbox_xfer_msg(device_t, struct scmi_msg *);
62 static int scmi_mailbox_poll_msg(device_t, struct scmi_msg *,
63 unsigned int);
64 static int scmi_mailbox_collect_reply(device_t, struct scmi_msg *);
65 static void scmi_mailbox_tx_complete(device_t, void *);
66
67 static int scmi_mailbox_probe(device_t);
68
69 static void
scmi_mailbox_a2p_callback(void * arg)70 scmi_mailbox_a2p_callback(void *arg)
71 {
72 struct scmi_mailbox_softc *sc;
73 uint32_t msg_header, rx_len;
74 int ret;
75
76 sc = arg;
77
78 ret = scmi_shmem_read_msg_header(sc->a2p_dev, &msg_header, &rx_len);
79 if (ret == 0)
80 scmi_rx_irq_callback(sc->base.dev, sc->a2p_dev, msg_header, rx_len);
81 }
82
83 static int
scmi_mailbox_transport_init(device_t dev)84 scmi_mailbox_transport_init(device_t dev)
85 {
86 struct scmi_mailbox_softc *sc;
87 phandle_t node;
88
89 sc = device_get_softc(dev);
90
91 node = ofw_bus_get_node(dev);
92 if (node == -1)
93 return (ENXIO);
94 /*
95 * TODO
96 * - Support P2A shmem + IRQ/doorbell
97 * - Support other mailbox devices
98 */
99 sc->a2p_dev = scmi_shmem_get(dev, node, SCMI_CHAN_A2P);
100 if (sc->a2p_dev == NULL) {
101 device_printf(dev, "A2P shmem dev not found.\n");
102 return (ENXIO);
103 }
104
105 /* TODO: Fix ofw_get...mbox doorbell names NOT required in Linux DT */
106 sc->db = arm_doorbell_ofw_get(dev, "tx");
107 if (sc->db == NULL) {
108 device_printf(dev, "Doorbell device not found.\n");
109 return (ENXIO);
110 }
111
112 sc->base.trs_desc.reply_timo_ms = 30;
113
114 arm_doorbell_set_handler(sc->db, scmi_mailbox_a2p_callback, sc);
115
116 return (0);
117 }
118
119 static void
scmi_mailbox_transport_cleanup(device_t dev)120 scmi_mailbox_transport_cleanup(device_t dev)
121 {
122 struct scmi_mailbox_softc *sc;
123
124 sc = device_get_softc(dev);
125
126 arm_doorbell_set_handler(sc->db, NULL, NULL);
127 }
128
129 static int
scmi_mailbox_xfer_msg(device_t dev,struct scmi_msg * msg)130 scmi_mailbox_xfer_msg(device_t dev, struct scmi_msg *msg)
131 {
132 struct scmi_mailbox_softc *sc;
133 int ret;
134
135 sc = device_get_softc(dev);
136
137 ret = scmi_shmem_prepare_msg(sc->a2p_dev, (uint8_t *)&msg->hdr,
138 msg->tx_len, msg->polling);
139 if (ret != 0)
140 return (ret);
141
142 /* Interrupt SCP firmware. */
143 arm_doorbell_set(sc->db);
144
145 return (0);
146 }
147
148 static int
scmi_mailbox_poll_msg(device_t dev,struct scmi_msg * msg,unsigned int tmo_ms)149 scmi_mailbox_poll_msg(device_t dev, struct scmi_msg *msg, unsigned int tmo_ms)
150 {
151 struct scmi_mailbox_softc *sc;
152 unsigned int tmo_loops = tmo_ms / SCMI_MBOX_POLL_INTERVAL_MS;
153
154 sc = device_get_softc(dev);
155
156 do {
157 if (scmi_shmem_poll_msg(sc->a2p_dev, &msg->hdr, &msg->rx_len))
158 break;
159 DELAY(SCMI_MBOX_POLL_INTERVAL_MS * 1000);
160 } while (tmo_loops--);
161
162 return (tmo_loops ? 0 : 1);
163 }
164
165 static int
scmi_mailbox_collect_reply(device_t dev,struct scmi_msg * msg)166 scmi_mailbox_collect_reply(device_t dev, struct scmi_msg *msg)
167 {
168 struct scmi_mailbox_softc *sc;
169 int ret;
170
171 sc = device_get_softc(dev);
172
173 ret = scmi_shmem_read_msg_payload(sc->a2p_dev,
174 msg->payld, msg->rx_len - SCMI_MSG_HDR_SIZE, msg->rx_len);
175
176 return (ret);
177 }
178
179 static void
scmi_mailbox_tx_complete(device_t dev,void * chan)180 scmi_mailbox_tx_complete(device_t dev, void *chan)
181 {
182 struct scmi_mailbox_softc *sc;
183
184 sc = device_get_softc(dev);
185 scmi_shmem_tx_complete(sc->a2p_dev);
186 }
187
188 static void
scmi_mailbox_clear_channel(device_t dev,void * chan)189 scmi_mailbox_clear_channel(device_t dev, void *chan)
190 {
191 /* Only P2A channel can be cleared forcibly by agent */
192 scmi_shmem_clear_channel(chan);
193 }
194
195 static int
scmi_mailbox_probe(device_t dev)196 scmi_mailbox_probe(device_t dev)
197 {
198
199 if (!ofw_bus_is_compatible(dev, "arm,scmi"))
200 return (ENXIO);
201
202 if (!ofw_bus_status_okay(dev))
203 return (ENXIO);
204
205 device_set_desc(dev, "ARM SCMI Mailbox Transport driver");
206
207 return (BUS_PROBE_DEFAULT);
208 }
209
210 static device_method_t scmi_mailbox_methods[] = {
211 DEVMETHOD(device_probe, scmi_mailbox_probe),
212
213 /* SCMI interface */
214 DEVMETHOD(scmi_transport_init, scmi_mailbox_transport_init),
215 DEVMETHOD(scmi_transport_cleanup, scmi_mailbox_transport_cleanup),
216 DEVMETHOD(scmi_xfer_msg, scmi_mailbox_xfer_msg),
217 DEVMETHOD(scmi_poll_msg, scmi_mailbox_poll_msg),
218 DEVMETHOD(scmi_collect_reply, scmi_mailbox_collect_reply),
219 DEVMETHOD(scmi_tx_complete, scmi_mailbox_tx_complete),
220 DEVMETHOD(scmi_clear_channel, scmi_mailbox_clear_channel),
221
222 DEVMETHOD_END
223 };
224
225 DEFINE_CLASS_1(scmi_mailbox, scmi_mailbox_driver, scmi_mailbox_methods,
226 sizeof(struct scmi_mailbox_softc), scmi_driver);
227
228 DRIVER_MODULE(scmi_mailbox, simplebus, scmi_mailbox_driver, 0, 0);
229 MODULE_VERSION(scmi_mailbox, 1);
230