| // SPDX-License-Identifier: GPL-2.0 |
| // |
| // Copyright 2018 Google LLC. |
| |
| #include <linux/completion.h> |
| #include <linux/delay.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/platform_data/cros_ec_commands.h> |
| #include <linux/platform_data/cros_ec_proto.h> |
| #include <linux/platform_device.h> |
| #include <linux/rpmsg.h> |
| #include <linux/slab.h> |
| |
| #define EC_MSG_TIMEOUT_MS 200 |
| #define HOST_COMMAND_MARK 1 |
| #define HOST_EVENT_MARK 2 |
| |
| /** |
| * struct cros_ec_rpmsg_response - rpmsg message format from from EC. |
| * |
| * @type: The type of message, should be either HOST_COMMAND_MARK or |
| * HOST_EVENT_MARK, representing that the message is a response to |
| * host command, or a host event. |
| * @data: ec_host_response for host command. |
| */ |
| struct cros_ec_rpmsg_response { |
| u8 type; |
| u8 data[] __aligned(4); |
| }; |
| |
| /** |
| * struct cros_ec_rpmsg - information about a EC over rpmsg. |
| * |
| * @rpdev: rpmsg device we are connected to |
| * @xfer_ack: completion for host command transfer. |
| * @host_event_work: Work struct for pending host event. |
| */ |
| struct cros_ec_rpmsg { |
| struct rpmsg_device *rpdev; |
| struct completion xfer_ack; |
| struct work_struct host_event_work; |
| struct rpmsg_endpoint *ept; |
| bool has_pending_host_event; |
| bool probe_done; |
| }; |
| |
| /** |
| * cros_ec_cmd_xfer_rpmsg - Transfer a message over rpmsg and receive the reply |
| * |
| * @ec_dev: ChromeOS EC device |
| * @ec_msg: Message to transfer |
| * |
| * This is only used for old EC proto version, and is not supported for this |
| * driver. |
| * |
| * Return: -EINVAL |
| */ |
| static int cros_ec_cmd_xfer_rpmsg(struct cros_ec_device *ec_dev, |
| struct cros_ec_command *ec_msg) |
| { |
| return -EINVAL; |
| } |
| |
| /** |
| * cros_ec_pkt_xfer_rpmsg - Transfer a packet over rpmsg and receive the reply |
| * |
| * @ec_dev: ChromeOS EC device |
| * @ec_msg: Message to transfer |
| * |
| * Return: number of bytes of the reply on success or negative error code. |
| */ |
| static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev, |
| struct cros_ec_command *ec_msg) |
| { |
| struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; |
| struct ec_host_response *response; |
| unsigned long timeout; |
| int len; |
| int ret; |
| u8 sum; |
| int i; |
| |
| ec_msg->result = 0; |
| len = cros_ec_prepare_tx(ec_dev, ec_msg); |
| dev_dbg(ec_dev->dev, "prepared, len=%d\n", len); |
| |
| reinit_completion(&ec_rpmsg->xfer_ack); |
| ret = rpmsg_send(ec_rpmsg->ept, ec_dev->dout, len); |
| if (ret) { |
| dev_err(ec_dev->dev, "rpmsg send failed\n"); |
| return ret; |
| } |
| |
| timeout = msecs_to_jiffies(EC_MSG_TIMEOUT_MS); |
| ret = wait_for_completion_timeout(&ec_rpmsg->xfer_ack, timeout); |
| if (!ret) { |
| dev_err(ec_dev->dev, "rpmsg send timeout\n"); |
| return -EIO; |
| } |
| |
| /* check response error code */ |
| response = (struct ec_host_response *)ec_dev->din; |
| ec_msg->result = response->result; |
| |
| ret = cros_ec_check_result(ec_dev, ec_msg); |
| if (ret) |
| goto exit; |
| |
| if (response->data_len > ec_msg->insize) { |
| dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)", |
| response->data_len, ec_msg->insize); |
| ret = -EMSGSIZE; |
| goto exit; |
| } |
| |
| /* copy response packet payload and compute checksum */ |
| memcpy(ec_msg->data, ec_dev->din + sizeof(*response), |
| response->data_len); |
| |
| sum = 0; |
| for (i = 0; i < sizeof(*response) + response->data_len; i++) |
| sum += ec_dev->din[i]; |
| |
| if (sum) { |
| dev_err(ec_dev->dev, "bad packet checksum, calculated %x\n", |
| sum); |
| ret = -EBADMSG; |
| goto exit; |
| } |
| |
| ret = response->data_len; |
| exit: |
| if (ec_msg->command == EC_CMD_REBOOT_EC) |
| msleep(EC_REBOOT_DELAY_MS); |
| |
| return ret; |
| } |
| |
| static void |
| cros_ec_rpmsg_host_event_function(struct work_struct *host_event_work) |
| { |
| struct cros_ec_rpmsg *ec_rpmsg = container_of(host_event_work, |
| struct cros_ec_rpmsg, |
| host_event_work); |
| struct cros_ec_device *ec_dev = dev_get_drvdata(&ec_rpmsg->rpdev->dev); |
| bool wake_event = true; |
| int ret; |
| |
| ret = cros_ec_get_next_event(ec_dev, &wake_event); |
| |
| /* |
| * Signal only if wake host events or any interrupt if |
| * cros_ec_get_next_event() returned an error (default value for |
| * wake_event is true) |
| */ |
| if (wake_event && device_may_wakeup(ec_dev->dev)) |
| pm_wakeup_event(ec_dev->dev, 0); |
| |
| if (ret > 0) |
| blocking_notifier_call_chain(&ec_dev->event_notifier, |
| 0, ec_dev); |
| } |
| |
| static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data, |
| int len, void *priv, u32 src) |
| { |
| struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev); |
| struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; |
| struct cros_ec_rpmsg_response *resp; |
| |
| if (!len) { |
| dev_warn(ec_dev->dev, "rpmsg received empty response"); |
| return -EINVAL; |
| } |
| |
| resp = data; |
| len -= offsetof(struct cros_ec_rpmsg_response, data); |
| if (resp->type == HOST_COMMAND_MARK) { |
| if (len > ec_dev->din_size) { |
| dev_warn(ec_dev->dev, |
| "received length %d > din_size %d, truncating", |
| len, ec_dev->din_size); |
| len = ec_dev->din_size; |
| } |
| |
| memcpy(ec_dev->din, resp->data, len); |
| complete(&ec_rpmsg->xfer_ack); |
| } else if (resp->type == HOST_EVENT_MARK) { |
| /* |
| * If the host event is sent before cros_ec_register is |
| * finished, queue the host event. |
| */ |
| if (ec_rpmsg->probe_done) |
| schedule_work(&ec_rpmsg->host_event_work); |
| else |
| ec_rpmsg->has_pending_host_event = true; |
| } else { |
| dev_warn(ec_dev->dev, "rpmsg received invalid type = %d", |
| resp->type); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static struct rpmsg_endpoint * |
| cros_ec_rpmsg_create_ept(struct rpmsg_device *rpdev) |
| { |
| struct rpmsg_channel_info chinfo = {}; |
| |
| strscpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE); |
| chinfo.src = rpdev->src; |
| chinfo.dst = RPMSG_ADDR_ANY; |
| |
| return rpmsg_create_ept(rpdev, cros_ec_rpmsg_callback, NULL, chinfo); |
| } |
| |
| static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev) |
| { |
| struct device *dev = &rpdev->dev; |
| struct cros_ec_rpmsg *ec_rpmsg; |
| struct cros_ec_device *ec_dev; |
| int ret; |
| |
| ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL); |
| if (!ec_dev) |
| return -ENOMEM; |
| |
| ec_rpmsg = devm_kzalloc(dev, sizeof(*ec_rpmsg), GFP_KERNEL); |
| if (!ec_rpmsg) |
| return -ENOMEM; |
| |
| ec_dev->dev = dev; |
| ec_dev->priv = ec_rpmsg; |
| ec_dev->cmd_xfer = cros_ec_cmd_xfer_rpmsg; |
| ec_dev->pkt_xfer = cros_ec_pkt_xfer_rpmsg; |
| ec_dev->phys_name = dev_name(&rpdev->dev); |
| ec_dev->din_size = sizeof(struct ec_host_response) + |
| sizeof(struct ec_response_get_protocol_info); |
| ec_dev->dout_size = sizeof(struct ec_host_request); |
| dev_set_drvdata(dev, ec_dev); |
| |
| ec_rpmsg->rpdev = rpdev; |
| init_completion(&ec_rpmsg->xfer_ack); |
| INIT_WORK(&ec_rpmsg->host_event_work, |
| cros_ec_rpmsg_host_event_function); |
| |
| ec_rpmsg->ept = cros_ec_rpmsg_create_ept(rpdev); |
| if (!ec_rpmsg->ept) |
| return -ENOMEM; |
| |
| ret = cros_ec_register(ec_dev); |
| if (ret < 0) { |
| rpmsg_destroy_ept(ec_rpmsg->ept); |
| cancel_work_sync(&ec_rpmsg->host_event_work); |
| return ret; |
| } |
| |
| ec_rpmsg->probe_done = true; |
| |
| if (ec_rpmsg->has_pending_host_event) |
| schedule_work(&ec_rpmsg->host_event_work); |
| |
| return 0; |
| } |
| |
| static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev) |
| { |
| struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev); |
| struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; |
| |
| cros_ec_unregister(ec_dev); |
| rpmsg_destroy_ept(ec_rpmsg->ept); |
| cancel_work_sync(&ec_rpmsg->host_event_work); |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int cros_ec_rpmsg_suspend(struct device *dev) |
| { |
| struct cros_ec_device *ec_dev = dev_get_drvdata(dev); |
| |
| return cros_ec_suspend(ec_dev); |
| } |
| |
| static int cros_ec_rpmsg_resume(struct device *dev) |
| { |
| struct cros_ec_device *ec_dev = dev_get_drvdata(dev); |
| |
| return cros_ec_resume(ec_dev); |
| } |
| #endif |
| |
| static SIMPLE_DEV_PM_OPS(cros_ec_rpmsg_pm_ops, cros_ec_rpmsg_suspend, |
| cros_ec_rpmsg_resume); |
| |
| static const struct of_device_id cros_ec_rpmsg_of_match[] = { |
| { .compatible = "google,cros-ec-rpmsg", }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, cros_ec_rpmsg_of_match); |
| |
| static struct rpmsg_driver cros_ec_driver_rpmsg = { |
| .drv = { |
| .name = "cros-ec-rpmsg", |
| .of_match_table = cros_ec_rpmsg_of_match, |
| .pm = &cros_ec_rpmsg_pm_ops, |
| }, |
| .probe = cros_ec_rpmsg_probe, |
| .remove = cros_ec_rpmsg_remove, |
| }; |
| |
| module_rpmsg_driver(cros_ec_driver_rpmsg); |
| |
| MODULE_LICENSE("GPL v2"); |
| MODULE_DESCRIPTION("ChromeOS EC multi function device (rpmsg)"); |