This driver implements the Greybus Bootrom protocol.
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/greybus/bootrom.c | 524 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 524 insertions(+)
--- /dev/null
+++ b/drivers/greybus/bootrom.c
@@ -0,0 +1,524 @@
+/*
+ * BOOTROM Greybus driver.
+ *
+ * Copyright 2016 Google Inc.
+ * Copyright 2016 Linaro Ltd.
+ *
+ * Released under the GPLv2 only.
+ */
+
+#include <linux/firmware.h>
+#include <linux/jiffies.h>
+#include <linux/mutex.h>
+#include <linux/workqueue.h>
+
+#include "greybus.h"
+#include "firmware.h"
+
+/* Timeout, in jiffies, within which the next request must be received */
+#define NEXT_REQ_TIMEOUT_MS 1000
+
+/*
+ * FIXME: Reduce this timeout once svc core handles parallel processing of
+ * events from the SVC, which are handled sequentially today.
+ */
+#define MODE_SWITCH_TIMEOUT_MS 10000
+
+enum next_request_type {
+ NEXT_REQ_FIRMWARE_SIZE,
+ NEXT_REQ_GET_FIRMWARE,
+ NEXT_REQ_READY_TO_BOOT,
+ NEXT_REQ_MODE_SWITCH,
+};
+
+struct gb_bootrom {
+ struct gb_connection *connection;
+ const struct firmware *fw;
+ u8 protocol_major;
+ u8 protocol_minor;
+ enum next_request_type next_request;
+ struct delayed_work dwork;
+ struct mutex mutex; /* Protects bootrom->fw */
+};
+
+static void free_firmware(struct gb_bootrom *bootrom)
+{
+ if (!bootrom->fw)
+ return;
+
+ release_firmware(bootrom->fw);
+ bootrom->fw = NULL;
+}
+
+static void gb_bootrom_timedout(struct work_struct *work)
+{
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct gb_bootrom *bootrom = container_of(dwork, struct gb_bootrom,
dwork);
+ struct device *dev = &bootrom->connection->bundle->dev;
+ const char *reason;
+
+ switch (bootrom->next_request) {
+ case NEXT_REQ_FIRMWARE_SIZE:
+ reason = "Firmware Size Request";
+ break;
+ case NEXT_REQ_GET_FIRMWARE:
+ reason = "Get Firmware Request";
+ break;
+ case NEXT_REQ_READY_TO_BOOT:
+ reason = "Ready to Boot Request";
+ break;
+ case NEXT_REQ_MODE_SWITCH:
+ reason = "Interface Mode Switch";
+ break;
+ default:
+ reason = NULL;
+ dev_err(dev, "Invalid next-request: %u", bootrom->next_request);
+ break;
+ }
+
+ dev_err(dev, "Timed out waiting for %s from the Module\n", reason);
+
+ mutex_lock(&bootrom->mutex);
+ free_firmware(bootrom);
+ mutex_unlock(&bootrom->mutex);
+
+ /* TODO: Power-off Module ? */
+}
+
+static void gb_bootrom_set_timeout(struct gb_bootrom *bootrom,
+ enum next_request_type next, unsigned long timeout)
+{
+ bootrom->next_request = next;
+ schedule_delayed_work(&bootrom->dwork, msecs_to_jiffies(timeout));
+}
+
+static void gb_bootrom_cancel_timeout(struct gb_bootrom *bootrom)
+{
+ cancel_delayed_work_sync(&bootrom->dwork);
+}
+
+/*
+ * The es2 chip doesn't have VID/PID programmed into the hardware and we need
to
+ * hack that up to distinguish different modules and their firmware blobs.
+ *
+ * This fetches VID/PID (over bootrom protocol) for es2 chip only, when VID/PID
+ * already sent during hotplug are 0.
+ *
+ * Otherwise, we keep intf->vendor_id/product_id same as what's passed
+ * during hotplug.
+ */
+static void bootrom_es2_fixup_vid_pid(struct gb_bootrom *bootrom)
+{
+ struct gb_bootrom_get_vid_pid_response response;
+ struct gb_connection *connection = bootrom->connection;
+ struct gb_interface *intf = connection->bundle->intf;
+ int ret;
+
+ if (!(intf->quirks & GB_INTERFACE_QUIRK_NO_GMP_IDS))
+ return;
+
+ ret = gb_operation_sync(connection, GB_BOOTROM_TYPE_GET_VID_PID,
+ NULL, 0, &response, sizeof(response));
+ if (ret) {
+ dev_err(&connection->bundle->dev,
+ "Bootrom get vid/pid operation failed (%d)\n", ret);
+ return;
+ }
+
+ /*
+ * NOTE: This is hacked, so that the same values of VID/PID can be used
+ * by next firmware level as well. The uevent for bootrom will still
+ * have VID/PID as 0, though after this point the sysfs files will start
+ * showing the updated values. But yeah, that's a bit racy as the same
+ * sysfs files would be showing 0 before this point.
+ */
+ intf->vendor_id = le32_to_cpu(response.vendor_id);
+ intf->product_id = le32_to_cpu(response.product_id);
+
+ dev_dbg(&connection->bundle->dev, "Bootrom got vid (0x%x)/pid (0x%x)\n",
+ intf->vendor_id, intf->product_id);
+}
+
+/* This returns path of the firmware blob on the disk */
+static int find_firmware(struct gb_bootrom *bootrom, u8 stage)
+{
+ struct gb_connection *connection = bootrom->connection;
+ struct gb_interface *intf = connection->bundle->intf;
+ char firmware_name[49];
+ int rc;
+
+ /* Already have a firmware, free it */
+ free_firmware(bootrom);
+
+ /* Bootrom protocol is only supported for loading Stage 2 firmware */
+ if (stage != 2) {
+ dev_err(&connection->bundle->dev, "Invalid boot stage: %u\n",
+ stage);
+ return -EINVAL;
+ }
+
+ /*
+ * Create firmware name
+ *
+ * XXX Name it properly..
+ */
+ snprintf(firmware_name, sizeof(firmware_name),
+ FW_NAME_PREFIX "%08x_%08x_%08x_%08x_s2l.tftf",
+ intf->ddbl1_manufacturer_id, intf->ddbl1_product_id,
+ intf->vendor_id, intf->product_id);
+
+ // FIXME:
+ // Turn to dev_dbg later after everyone has valid bootloaders with good
+ // ids, but leave this as dev_info for now to make it easier to track
+ // down "empty" vid/pid modules.
+ dev_info(&connection->bundle->dev, "Firmware file '%s' requested\n",
+ firmware_name);
+
+ rc = request_firmware(&bootrom->fw, firmware_name,
+ &connection->bundle->dev);
+ if (rc) {
+ dev_err(&connection->bundle->dev,
+ "failed to find %s firmware (%d)\n", firmware_name, rc);
+ }
+
+ return rc;
+}
+
+static int gb_bootrom_firmware_size_request(struct gb_operation *op)
+{
+ struct gb_bootrom *bootrom = gb_connection_get_data(op->connection);
+ struct gb_bootrom_firmware_size_request *size_request =
op->request->payload;
+ struct gb_bootrom_firmware_size_response *size_response;
+ struct device *dev = &op->connection->bundle->dev;
+ int ret;
+
+ /* Disable timeouts */
+ gb_bootrom_cancel_timeout(bootrom);
+
+ if (op->request->payload_size != sizeof(*size_request)) {
+ dev_err(dev, "%s: illegal size of firmware size request (%zu !=
%zu)\n",
+ __func__, op->request->payload_size,
+ sizeof(*size_request));
+ ret = -EINVAL;
+ goto queue_work;
+ }
+
+ mutex_lock(&bootrom->mutex);
+
+ ret = find_firmware(bootrom, size_request->stage);
+ if (ret)
+ goto unlock;
+
+ if (!gb_operation_response_alloc(op, sizeof(*size_response),
+ GFP_KERNEL)) {
+ dev_err(dev, "%s: error allocating response\n", __func__);
+ free_firmware(bootrom);
+ ret = -ENOMEM;
+ goto unlock;
+ }
+
+ size_response = op->response->payload;
+ size_response->size = cpu_to_le32(bootrom->fw->size);
+
+ dev_dbg(dev, "%s: firmware size %d bytes\n", __func__,
size_response->size);
+
+unlock:
+ mutex_unlock(&bootrom->mutex);
+
+queue_work:
+ if (!ret) {
+ /* Refresh timeout */
+ gb_bootrom_set_timeout(bootrom, NEXT_REQ_GET_FIRMWARE,
+ NEXT_REQ_TIMEOUT_MS);
+ }
+
+ return ret;
+}
+
+static int gb_bootrom_get_firmware(struct gb_operation *op)
+{
+ struct gb_bootrom *bootrom = gb_connection_get_data(op->connection);
+ const struct firmware *fw;
+ struct gb_bootrom_get_firmware_request *firmware_request;
+ struct gb_bootrom_get_firmware_response *firmware_response;
+ struct device *dev = &op->connection->bundle->dev;
+ unsigned int offset, size;
+ enum next_request_type next_request;
+ int ret = 0;
+
+ /* Disable timeouts */
+ gb_bootrom_cancel_timeout(bootrom);
+
+ if (op->request->payload_size != sizeof(*firmware_request)) {
+ dev_err(dev, "%s: Illegal size of get firmware request (%zu
%zu)\n",
+ __func__, op->request->payload_size,
+ sizeof(*firmware_request));
+ ret = -EINVAL;
+ goto queue_work;
+ }
+
+ mutex_lock(&bootrom->mutex);
+
+ fw = bootrom->fw;
+ if (!fw) {
+ dev_err(dev, "%s: firmware not available\n", __func__);
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ firmware_request = op->request->payload;
+ offset = le32_to_cpu(firmware_request->offset);
+ size = le32_to_cpu(firmware_request->size);
+
+ if (offset >= fw->size || size > fw->size - offset) {
+ dev_warn(dev, "bad firmware request (offs = %u, size = %u)\n",
+ offset, size);
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ if (!gb_operation_response_alloc(op, sizeof(*firmware_response) + size,
+ GFP_KERNEL)) {
+ dev_err(dev, "%s: error allocating response\n", __func__);
+ ret = -ENOMEM;
+ goto unlock;
+ }
+
+ firmware_response = op->response->payload;
+ memcpy(firmware_response->data, fw->data + offset, size);
+
+ dev_dbg(dev, "responding with firmware (offs = %u, size = %u)\n",
offset,
+ size);
+
+unlock:
+ mutex_unlock(&bootrom->mutex);
+
+queue_work:
+ /* Refresh timeout */
+ if (!ret && (offset + size == fw->size))
+ next_request = NEXT_REQ_READY_TO_BOOT;
+ else
+ next_request = NEXT_REQ_GET_FIRMWARE;
+
+ gb_bootrom_set_timeout(bootrom, next_request, NEXT_REQ_TIMEOUT_MS);
+
+ return ret;
+}
+
+static int gb_bootrom_ready_to_boot(struct gb_operation *op)
+{
+ struct gb_connection *connection = op->connection;
+ struct gb_bootrom *bootrom = gb_connection_get_data(connection);
+ struct gb_bootrom_ready_to_boot_request *rtb_request;
+ struct device *dev = &connection->bundle->dev;
+ u8 status;
+ int ret = 0;
+
+ /* Disable timeouts */
+ gb_bootrom_cancel_timeout(bootrom);
+
+ if (op->request->payload_size != sizeof(*rtb_request)) {
+ dev_err(dev, "%s: Illegal size of ready to boot request (%zu
%zu)\n",
+ __func__, op->request->payload_size,
+ sizeof(*rtb_request));
+ ret = -EINVAL;
+ goto queue_work;
+ }
+
+ rtb_request = op->request->payload;
+ status = rtb_request->status;
+
+ /* Return error if the blob was invalid */
+ if (status == GB_BOOTROM_BOOT_STATUS_INVALID) {
+ ret = -EINVAL;
+ goto queue_work;
+ }
+
+ /*
+ * XXX Should we return error for insecure firmware?
+ */
+ dev_dbg(dev, "ready to boot: 0x%x, 0\n", status);
+
+queue_work:
+ /*
+ * Refresh timeout, the Interface shall load the new personality and
+ * send a new hotplug request, which shall get rid of the bootrom
+ * connection. As that can take some time, increase the timeout a bit.
+ */
+ gb_bootrom_set_timeout(bootrom, NEXT_REQ_MODE_SWITCH,
+ MODE_SWITCH_TIMEOUT_MS);
+
+ return ret;
+}
+
+static int gb_bootrom_request_handler(struct gb_operation *op)
+{
+ u8 type = op->type;
+
+ switch (type) {
+ case GB_BOOTROM_TYPE_FIRMWARE_SIZE:
+ return gb_bootrom_firmware_size_request(op);
+ case GB_BOOTROM_TYPE_GET_FIRMWARE:
+ return gb_bootrom_get_firmware(op);
+ case GB_BOOTROM_TYPE_READY_TO_BOOT:
+ return gb_bootrom_ready_to_boot(op);
+ default:
+ dev_err(&op->connection->bundle->dev,
+ "unsupported request: %u\n", type);
+ return -EINVAL;
+ }
+}
+
+static int gb_bootrom_get_version(struct gb_bootrom *bootrom)
+{
+ struct gb_bundle *bundle = bootrom->connection->bundle;
+ struct gb_bootrom_version_request request;
+ struct gb_bootrom_version_response response;
+ int ret;
+
+ request.major = GB_BOOTROM_VERSION_MAJOR;
+ request.minor = GB_BOOTROM_VERSION_MINOR;
+
+ ret = gb_operation_sync(bootrom->connection,
+ GB_BOOTROM_TYPE_VERSION,
+ &request, sizeof(request), &response,
+ sizeof(response));
+ if (ret) {
+ dev_err(&bundle->dev,
+ "failed to get protocol version: %d\n",
+ ret);
+ return ret;
+ }
+
+ if (response.major > request.major) {
+ dev_err(&bundle->dev,
+ "unsupported major protocol version (%u >
%u)\n",
+ response.major, request.major);
+ return -ENOTSUPP;
+ }
+
+ bootrom->protocol_major = response.major;
+ bootrom->protocol_minor = response.minor;
+
+ dev_dbg(&bundle->dev, "%s - %u.%u\n", __func__, response.major,
+ response.minor);
+
+ return 0;
+}
+
+static int gb_bootrom_probe(struct gb_bundle *bundle,
+ const struct greybus_bundle_id *id)
+{
+ struct greybus_descriptor_cport *cport_desc;
+ struct gb_connection *connection;
+ struct gb_bootrom *bootrom;
+ int ret;
+
+ if (bundle->num_cports != 1)
+ return -ENODEV;
+
+ cport_desc = &bundle->cport_desc[0];
+ if (cport_desc->protocol_id != GREYBUS_PROTOCOL_BOOTROM)
+ return -ENODEV;
+
+ bootrom = kzalloc(sizeof(*bootrom), GFP_KERNEL);
+ if (!bootrom)
+ return -ENOMEM;
+
+ connection = gb_connection_create(bundle,
+ le16_to_cpu(cport_desc->id),
+ gb_bootrom_request_handler);
+ if (IS_ERR(connection)) {
+ ret = PTR_ERR(connection);
+ goto err_free_bootrom;
+ }
+
+ gb_connection_set_data(connection, bootrom);
+
+ bootrom->connection = connection;
+
+ mutex_init(&bootrom->mutex);
+ INIT_DELAYED_WORK(&bootrom->dwork, gb_bootrom_timedout);
+ greybus_set_drvdata(bundle, bootrom);
+
+ ret = gb_connection_enable_tx(connection);
+ if (ret)
+ goto err_connection_destroy;
+
+ ret = gb_bootrom_get_version(bootrom);
+ if (ret)
+ goto err_connection_disable;
+
+ bootrom_es2_fixup_vid_pid(bootrom);
+
+ ret = gb_connection_enable(connection);
+ if (ret)
+ goto err_connection_disable;
+
+ /* Refresh timeout */
+ gb_bootrom_set_timeout(bootrom, NEXT_REQ_FIRMWARE_SIZE,
+ NEXT_REQ_TIMEOUT_MS);
+
+ /* Tell bootrom we're ready. */
+ ret = gb_operation_sync(connection, GB_BOOTROM_TYPE_AP_READY, NULL, 0,
+ NULL, 0);
+ if (ret) {
+ dev_err(&connection->bundle->dev,
+ "failed to send AP READY: %d\n", ret);
+ goto err_cancel_timeout;
+ }
+
+ dev_dbg(&bundle->dev, "AP_READY sent\n");
+
+ return 0;
+
+err_cancel_timeout:
+ gb_bootrom_cancel_timeout(bootrom);
+err_connection_disable:
+ gb_connection_disable(connection);
+err_connection_destroy:
+ gb_connection_destroy(connection);
+err_free_bootrom:
+ kfree(bootrom);
+
+ return ret;
+}
+
+static void gb_bootrom_disconnect(struct gb_bundle *bundle)
+{
+ struct gb_bootrom *bootrom = greybus_get_drvdata(bundle);
+
+ dev_dbg(&bundle->dev, "%s\n", __func__);
+
+ gb_connection_disable(bootrom->connection);
+
+ /* Disable timeouts */
+ gb_bootrom_cancel_timeout(bootrom);
+
+ /*
+ * Release firmware:
+ *
+ * As the connection and the delayed work are already disabled, we don't
+ * need to lock access to bootrom->fw here.
+ */
+ free_firmware(bootrom);
+
+ gb_connection_destroy(bootrom->connection);
+ kfree(bootrom);
+}
+
+static const struct greybus_bundle_id gb_bootrom_id_table[] = {
+ { GREYBUS_DEVICE_CLASS(GREYBUS_CLASS_BOOTROM) },
+ { }
+};
+
+static struct greybus_driver gb_bootrom_driver = {
+ .name = "bootrom",
+ .probe = gb_bootrom_probe,
+ .disconnect = gb_bootrom_disconnect,
+ .id_table = gb_bootrom_id_table,
+};
+
+module_greybus_driver(gb_bootrom_driver);
+
+MODULE_LICENSE("GPL v2");
