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Diffstat (limited to 'sys/dev/firmware/arm/scmi.c')
| -rw-r--r-- | sys/dev/firmware/arm/scmi.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/sys/dev/firmware/arm/scmi.c b/sys/dev/firmware/arm/scmi.c new file mode 100644 index 000000000000..deb334ecfb68 --- /dev/null +++ b/sys/dev/firmware/arm/scmi.c @@ -0,0 +1,273 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2022 Ruslan Bukin <br@bsdpad.com> + * + * This work was supported by Innovate UK project 105694, "Digital Security + * by Design (DSbD) Technology Platform Prototype". + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/bus.h> +#include <sys/cpu.h> +#include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/module.h> +#include <sys/mutex.h> + +#include <dev/extres/clk/clk.h> +#include <dev/fdt/simplebus.h> +#include <dev/fdt/fdt_common.h> +#include <dev/ofw/ofw_bus_subr.h> + +#include "dev/mailbox/arm/arm_doorbell.h" + +#include "scmi.h" +#include "scmi_protocols.h" + +struct scmi_softc { + struct simplebus_softc simplebus_sc; + device_t dev; + device_t tx_shmem; + struct arm_doorbell *db; + struct mtx mtx; + int req_done; +}; + +static device_t +scmi_get_shmem(struct scmi_softc *sc, int index) +{ + phandle_t *shmems; + phandle_t node; + device_t dev; + size_t len; + + node = ofw_bus_get_node(sc->dev); + if (node <= 0) + return (NULL); + + len = OF_getencprop_alloc_multi(node, "shmem", sizeof(*shmems), + (void **)&shmems); + if (len <= 0) { + device_printf(sc->dev, "%s: Can't get shmem node.\n", __func__); + return (NULL); + } + + if (index >= len) { + OF_prop_free(shmems); + return (NULL); + } + + dev = OF_device_from_xref(shmems[index]); + if (dev == NULL) + device_printf(sc->dev, "%s: Can't get shmem device.\n", + __func__); + + OF_prop_free(shmems); + + return (dev); +} + +static void +scmi_callback(void *arg) +{ + struct scmi_softc *sc; + + sc = arg; + + dprintf("%s sc %p\n", __func__, sc); + + SCMI_LOCK(sc); + sc->req_done = 1; + wakeup(sc); + SCMI_UNLOCK(sc); +} + +static int +scmi_request_locked(struct scmi_softc *sc, struct scmi_req *req) +{ + struct scmi_smt_header hdr; + int timeout; + + bzero(&hdr, sizeof(struct scmi_smt_header)); + + SCMI_ASSERT_LOCKED(sc); + + /* Read header */ + scmi_shmem_read(sc->tx_shmem, 0, &hdr, SMT_HEADER_SIZE); + + if ((hdr.channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE) == 0) + return (1); + + /* Update header */ + hdr.channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE; + hdr.msg_header = req->protocol_id << SMT_HEADER_PROTOCOL_ID_S; + hdr.msg_header |= req->message_id << SMT_HEADER_MESSAGE_ID_S; + hdr.length = sizeof(hdr.msg_header) + req->in_size; + hdr.flags |= SCMI_SHMEM_FLAG_INTR_ENABLED; + + /* Write header */ + scmi_shmem_write(sc->tx_shmem, 0, &hdr, SMT_HEADER_SIZE); + + /* Write request */ + scmi_shmem_write(sc->tx_shmem, SMT_HEADER_SIZE, req->in_buf, + req->in_size); + + sc->req_done = 0; + + /* Interrupt SCP firmware. */ + arm_doorbell_set(sc->db); + + timeout = 200; + + dprintf("%s: request\n", __func__); + + do { + if (cold) { + if (arm_doorbell_get(sc->db)) + break; + DELAY(10000); + } else { + msleep(sc, &sc->mtx, 0, "scmi", hz / 10); + if (sc->req_done) + break; + } + } while (timeout--); + + if (timeout <= 0) + return (-1); + + dprintf("%s: got reply, timeout %d\n", __func__, timeout); + + /* Read header. */ + scmi_shmem_read(sc->tx_shmem, 0, &hdr, SMT_HEADER_SIZE); + + /* Read response */ + scmi_shmem_read(sc->tx_shmem, SMT_HEADER_SIZE, req->out_buf, + req->out_size); + + return (0); +} + +int +scmi_request(device_t dev, struct scmi_req *req) +{ + struct scmi_softc *sc; + int error; + + sc = device_get_softc(dev); + + SCMI_LOCK(sc); + error = scmi_request_locked(sc, req); + SCMI_UNLOCK(sc); + + return (error); +} + +static int +scmi_probe(device_t dev) +{ + + if (!ofw_bus_is_compatible(dev, "arm,scmi")) + return (ENXIO); + + if (!ofw_bus_status_okay(dev)) + return (ENXIO); + + device_set_desc(dev, "ARM SCMI interface driver"); + + return (BUS_PROBE_DEFAULT); +} + +static int +scmi_attach(device_t dev) +{ + struct scmi_softc *sc; + phandle_t node; + int error; + + sc = device_get_softc(dev); + sc->dev = dev; + + node = ofw_bus_get_node(dev); + if (node == -1) + return (ENXIO); + + sc->tx_shmem = scmi_get_shmem(sc, 0); + if (sc->tx_shmem == NULL) { + device_printf(dev, "TX shmem dev not found.\n"); + return (ENXIO); + } + + sc->db = arm_doorbell_ofw_get(sc->dev, "tx"); + if (sc->db == NULL) { + device_printf(dev, "Doorbell device not found.\n"); + return (ENXIO); + } + + mtx_init(&sc->mtx, device_get_nameunit(dev), "SCMI", MTX_DEF); + + arm_doorbell_set_handler(sc->db, scmi_callback, sc); + + simplebus_init(dev, node); + + /* + * Allow devices to identify. + */ + bus_generic_probe(dev); + + /* + * Now walk the OFW tree and attach top-level devices. + */ + for (node = OF_child(node); node > 0; node = OF_peer(node)) + simplebus_add_device(dev, node, 0, NULL, -1, NULL); + + error = bus_generic_attach(dev); + + return (error); +} + +static int +scmi_detach(device_t dev) +{ + + return (0); +} + +static device_method_t scmi_methods[] = { + DEVMETHOD(device_probe, scmi_probe), + DEVMETHOD(device_attach, scmi_attach), + DEVMETHOD(device_detach, scmi_detach), + DEVMETHOD_END +}; + +DEFINE_CLASS_1(scmi, scmi_driver, scmi_methods, sizeof(struct scmi_softc), + simplebus_driver); + +DRIVER_MODULE(scmi, simplebus, scmi_driver, 0, 0); +MODULE_VERSION(scmi, 1); |