diff options
Diffstat (limited to 'drivers/soc/qcom/glink_ssr.c')
| -rw-r--r-- | drivers/soc/qcom/glink_ssr.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/soc/qcom/glink_ssr.c b/drivers/soc/qcom/glink_ssr.c new file mode 100644 index 000000000000..19c7399eddb5 --- /dev/null +++ b/drivers/soc/qcom/glink_ssr.c @@ -0,0 +1,164 @@ +/* + * Copyright (c) 2014-2017, The Linux Foundation. All rights reserved. + * Copyright (c) 2017, Linaro Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/completion.h> +#include <linux/module.h> +#include <linux/notifier.h> +#include <linux/rpmsg.h> +#include <linux/remoteproc/qcom_rproc.h> + +/** + * struct do_cleanup_msg - The data structure for an SSR do_cleanup message + * version: The G-Link SSR protocol version + * command: The G-Link SSR command - do_cleanup + * seq_num: Sequence number + * name_len: Length of the name of the subsystem being restarted + * name: G-Link edge name of the subsystem being restarted + */ +struct do_cleanup_msg { + __le32 version; + __le32 command; + __le32 seq_num; + __le32 name_len; + char name[32]; +}; + +/** + * struct cleanup_done_msg - The data structure for an SSR cleanup_done message + * version: The G-Link SSR protocol version + * response: The G-Link SSR response to a do_cleanup command, cleanup_done + * seq_num: Sequence number + */ +struct cleanup_done_msg { + __le32 version; + __le32 response; + __le32 seq_num; +}; + +/** + * G-Link SSR protocol commands + */ +#define GLINK_SSR_DO_CLEANUP 0 +#define GLINK_SSR_CLEANUP_DONE 1 + +struct glink_ssr { + struct device *dev; + struct rpmsg_endpoint *ept; + + struct notifier_block nb; + + u32 seq_num; + struct completion completion; +}; + +static int qcom_glink_ssr_callback(struct rpmsg_device *rpdev, + void *data, int len, void *priv, u32 addr) +{ + struct cleanup_done_msg *msg = data; + struct glink_ssr *ssr = dev_get_drvdata(&rpdev->dev); + + if (len < sizeof(*msg)) { + dev_err(ssr->dev, "message too short\n"); + return -EINVAL; + } + + if (le32_to_cpu(msg->version) != 0) + return -EINVAL; + + if (le32_to_cpu(msg->response) != GLINK_SSR_CLEANUP_DONE) + return 0; + + if (le32_to_cpu(msg->seq_num) != ssr->seq_num) { + dev_err(ssr->dev, "invalid sequence number of response\n"); + return -EINVAL; + } + + complete(&ssr->completion); + + return 0; +} + +static int qcom_glink_ssr_notify(struct notifier_block *nb, unsigned long event, + void *data) +{ + struct glink_ssr *ssr = container_of(nb, struct glink_ssr, nb); + struct do_cleanup_msg msg; + char *ssr_name = data; + int ret; + + ssr->seq_num++; + reinit_completion(&ssr->completion); + + memset(&msg, 0, sizeof(msg)); + msg.command = cpu_to_le32(GLINK_SSR_DO_CLEANUP); + msg.seq_num = cpu_to_le32(ssr->seq_num); + msg.name_len = cpu_to_le32(strlen(ssr_name)); + strlcpy(msg.name, ssr_name, sizeof(msg.name)); + + ret = rpmsg_send(ssr->ept, &msg, sizeof(msg)); + if (ret < 0) + dev_err(ssr->dev, "failed to send cleanup message\n"); + + ret = wait_for_completion_timeout(&ssr->completion, HZ); + if (!ret) + dev_err(ssr->dev, "timeout waiting for cleanup done message\n"); + + return NOTIFY_DONE; +} + +static int qcom_glink_ssr_probe(struct rpmsg_device *rpdev) +{ + struct glink_ssr *ssr; + + ssr = devm_kzalloc(&rpdev->dev, sizeof(*ssr), GFP_KERNEL); + if (!ssr) + return -ENOMEM; + + init_completion(&ssr->completion); + + ssr->dev = &rpdev->dev; + ssr->ept = rpdev->ept; + ssr->nb.notifier_call = qcom_glink_ssr_notify; + + dev_set_drvdata(&rpdev->dev, ssr); + + return qcom_register_ssr_notifier(&ssr->nb); +} + +static void qcom_glink_ssr_remove(struct rpmsg_device *rpdev) +{ + struct glink_ssr *ssr = dev_get_drvdata(&rpdev->dev); + + qcom_unregister_ssr_notifier(&ssr->nb); +} + +static const struct rpmsg_device_id qcom_glink_ssr_match[] = { + { "glink_ssr" }, + {} +}; + +static struct rpmsg_driver qcom_glink_ssr_driver = { + .probe = qcom_glink_ssr_probe, + .remove = qcom_glink_ssr_remove, + .callback = qcom_glink_ssr_callback, + .id_table = qcom_glink_ssr_match, + .drv = { + .name = "qcom_glink_ssr", + }, +}; +module_rpmsg_driver(qcom_glink_ssr_driver); + +MODULE_ALIAS("rpmsg:glink_ssr"); +MODULE_DESCRIPTION("Qualcomm GLINK SSR notifier"); +MODULE_LICENSE("GPL v2"); |