12de89fd9SPi-Hsun Shih // SPDX-License-Identifier: GPL-2.0
22de89fd9SPi-Hsun Shih //
32de89fd9SPi-Hsun Shih // Copyright 2018 Google LLC.
42de89fd9SPi-Hsun Shih
52de89fd9SPi-Hsun Shih #include <linux/completion.h>
62de89fd9SPi-Hsun Shih #include <linux/delay.h>
72de89fd9SPi-Hsun Shih #include <linux/kernel.h>
82de89fd9SPi-Hsun Shih #include <linux/module.h>
92de89fd9SPi-Hsun Shih #include <linux/of.h>
10840d9f13SEnric Balletbo i Serra #include <linux/platform_data/cros_ec_commands.h>
11840d9f13SEnric Balletbo i Serra #include <linux/platform_data/cros_ec_proto.h>
122de89fd9SPi-Hsun Shih #include <linux/platform_device.h>
132de89fd9SPi-Hsun Shih #include <linux/rpmsg.h>
142de89fd9SPi-Hsun Shih #include <linux/slab.h>
152de89fd9SPi-Hsun Shih
16034dbec1SEnric Balletbo i Serra #include "cros_ec.h"
17034dbec1SEnric Balletbo i Serra
182de89fd9SPi-Hsun Shih #define EC_MSG_TIMEOUT_MS 200
192de89fd9SPi-Hsun Shih #define HOST_COMMAND_MARK 1
202de89fd9SPi-Hsun Shih #define HOST_EVENT_MARK 2
212de89fd9SPi-Hsun Shih
222de89fd9SPi-Hsun Shih /**
232de89fd9SPi-Hsun Shih * struct cros_ec_rpmsg_response - rpmsg message format from from EC.
242de89fd9SPi-Hsun Shih *
252de89fd9SPi-Hsun Shih * @type: The type of message, should be either HOST_COMMAND_MARK or
262de89fd9SPi-Hsun Shih * HOST_EVENT_MARK, representing that the message is a response to
272de89fd9SPi-Hsun Shih * host command, or a host event.
282de89fd9SPi-Hsun Shih * @data: ec_host_response for host command.
292de89fd9SPi-Hsun Shih */
302de89fd9SPi-Hsun Shih struct cros_ec_rpmsg_response {
312de89fd9SPi-Hsun Shih u8 type;
322de89fd9SPi-Hsun Shih u8 data[] __aligned(4);
332de89fd9SPi-Hsun Shih };
342de89fd9SPi-Hsun Shih
352de89fd9SPi-Hsun Shih /**
362de89fd9SPi-Hsun Shih * struct cros_ec_rpmsg - information about a EC over rpmsg.
372de89fd9SPi-Hsun Shih *
382de89fd9SPi-Hsun Shih * @rpdev: rpmsg device we are connected to
392de89fd9SPi-Hsun Shih * @xfer_ack: completion for host command transfer.
402de89fd9SPi-Hsun Shih * @host_event_work: Work struct for pending host event.
419a876ba5SEnric Balletbo i Serra * @ept: The rpmsg endpoint of this channel.
429a876ba5SEnric Balletbo i Serra * @has_pending_host_event: Boolean used to check if there is a pending event.
439a876ba5SEnric Balletbo i Serra * @probe_done: Flag to indicate that probe is done.
442de89fd9SPi-Hsun Shih */
452de89fd9SPi-Hsun Shih struct cros_ec_rpmsg {
462de89fd9SPi-Hsun Shih struct rpmsg_device *rpdev;
472de89fd9SPi-Hsun Shih struct completion xfer_ack;
482de89fd9SPi-Hsun Shih struct work_struct host_event_work;
4971cddb70SPi-Hsun Shih struct rpmsg_endpoint *ept;
50f775ac78SPi-Hsun Shih bool has_pending_host_event;
51f775ac78SPi-Hsun Shih bool probe_done;
522de89fd9SPi-Hsun Shih };
532de89fd9SPi-Hsun Shih
542de89fd9SPi-Hsun Shih /**
552de89fd9SPi-Hsun Shih * cros_ec_cmd_xfer_rpmsg - Transfer a message over rpmsg and receive the reply
562de89fd9SPi-Hsun Shih *
572de89fd9SPi-Hsun Shih * @ec_dev: ChromeOS EC device
582de89fd9SPi-Hsun Shih * @ec_msg: Message to transfer
592de89fd9SPi-Hsun Shih *
602de89fd9SPi-Hsun Shih * This is only used for old EC proto version, and is not supported for this
612de89fd9SPi-Hsun Shih * driver.
622de89fd9SPi-Hsun Shih *
632de89fd9SPi-Hsun Shih * Return: -EINVAL
642de89fd9SPi-Hsun Shih */
cros_ec_cmd_xfer_rpmsg(struct cros_ec_device * ec_dev,struct cros_ec_command * ec_msg)652de89fd9SPi-Hsun Shih static int cros_ec_cmd_xfer_rpmsg(struct cros_ec_device *ec_dev,
662de89fd9SPi-Hsun Shih struct cros_ec_command *ec_msg)
672de89fd9SPi-Hsun Shih {
682de89fd9SPi-Hsun Shih return -EINVAL;
692de89fd9SPi-Hsun Shih }
702de89fd9SPi-Hsun Shih
712de89fd9SPi-Hsun Shih /**
722de89fd9SPi-Hsun Shih * cros_ec_pkt_xfer_rpmsg - Transfer a packet over rpmsg and receive the reply
732de89fd9SPi-Hsun Shih *
742de89fd9SPi-Hsun Shih * @ec_dev: ChromeOS EC device
752de89fd9SPi-Hsun Shih * @ec_msg: Message to transfer
762de89fd9SPi-Hsun Shih *
772de89fd9SPi-Hsun Shih * Return: number of bytes of the reply on success or negative error code.
782de89fd9SPi-Hsun Shih */
cros_ec_pkt_xfer_rpmsg(struct cros_ec_device * ec_dev,struct cros_ec_command * ec_msg)792de89fd9SPi-Hsun Shih static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev,
802de89fd9SPi-Hsun Shih struct cros_ec_command *ec_msg)
812de89fd9SPi-Hsun Shih {
822de89fd9SPi-Hsun Shih struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
832de89fd9SPi-Hsun Shih struct ec_host_response *response;
842de89fd9SPi-Hsun Shih unsigned long timeout;
852de89fd9SPi-Hsun Shih int len;
862de89fd9SPi-Hsun Shih int ret;
872de89fd9SPi-Hsun Shih u8 sum;
882de89fd9SPi-Hsun Shih int i;
892de89fd9SPi-Hsun Shih
902de89fd9SPi-Hsun Shih ec_msg->result = 0;
912de89fd9SPi-Hsun Shih len = cros_ec_prepare_tx(ec_dev, ec_msg);
92*71d3ae7fSTzung-Bi Shih if (len < 0)
93*71d3ae7fSTzung-Bi Shih return len;
942de89fd9SPi-Hsun Shih dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
952de89fd9SPi-Hsun Shih
962de89fd9SPi-Hsun Shih reinit_completion(&ec_rpmsg->xfer_ack);
9771cddb70SPi-Hsun Shih ret = rpmsg_send(ec_rpmsg->ept, ec_dev->dout, len);
982de89fd9SPi-Hsun Shih if (ret) {
992de89fd9SPi-Hsun Shih dev_err(ec_dev->dev, "rpmsg send failed\n");
1002de89fd9SPi-Hsun Shih return ret;
1012de89fd9SPi-Hsun Shih }
1022de89fd9SPi-Hsun Shih
1032de89fd9SPi-Hsun Shih timeout = msecs_to_jiffies(EC_MSG_TIMEOUT_MS);
1042de89fd9SPi-Hsun Shih ret = wait_for_completion_timeout(&ec_rpmsg->xfer_ack, timeout);
1052de89fd9SPi-Hsun Shih if (!ret) {
1062de89fd9SPi-Hsun Shih dev_err(ec_dev->dev, "rpmsg send timeout\n");
1072de89fd9SPi-Hsun Shih return -EIO;
1082de89fd9SPi-Hsun Shih }
1092de89fd9SPi-Hsun Shih
1102de89fd9SPi-Hsun Shih /* check response error code */
1112de89fd9SPi-Hsun Shih response = (struct ec_host_response *)ec_dev->din;
1122de89fd9SPi-Hsun Shih ec_msg->result = response->result;
1132de89fd9SPi-Hsun Shih
1142de89fd9SPi-Hsun Shih ret = cros_ec_check_result(ec_dev, ec_msg);
1152de89fd9SPi-Hsun Shih if (ret)
1162de89fd9SPi-Hsun Shih goto exit;
1172de89fd9SPi-Hsun Shih
1182de89fd9SPi-Hsun Shih if (response->data_len > ec_msg->insize) {
1192de89fd9SPi-Hsun Shih dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
1202de89fd9SPi-Hsun Shih response->data_len, ec_msg->insize);
1212de89fd9SPi-Hsun Shih ret = -EMSGSIZE;
1222de89fd9SPi-Hsun Shih goto exit;
1232de89fd9SPi-Hsun Shih }
1242de89fd9SPi-Hsun Shih
1252de89fd9SPi-Hsun Shih /* copy response packet payload and compute checksum */
1262de89fd9SPi-Hsun Shih memcpy(ec_msg->data, ec_dev->din + sizeof(*response),
1272de89fd9SPi-Hsun Shih response->data_len);
1282de89fd9SPi-Hsun Shih
1292de89fd9SPi-Hsun Shih sum = 0;
1302de89fd9SPi-Hsun Shih for (i = 0; i < sizeof(*response) + response->data_len; i++)
1312de89fd9SPi-Hsun Shih sum += ec_dev->din[i];
1322de89fd9SPi-Hsun Shih
1332de89fd9SPi-Hsun Shih if (sum) {
1342de89fd9SPi-Hsun Shih dev_err(ec_dev->dev, "bad packet checksum, calculated %x\n",
1352de89fd9SPi-Hsun Shih sum);
1362de89fd9SPi-Hsun Shih ret = -EBADMSG;
1372de89fd9SPi-Hsun Shih goto exit;
1382de89fd9SPi-Hsun Shih }
1392de89fd9SPi-Hsun Shih
1402de89fd9SPi-Hsun Shih ret = response->data_len;
1412de89fd9SPi-Hsun Shih exit:
1422de89fd9SPi-Hsun Shih if (ec_msg->command == EC_CMD_REBOOT_EC)
1432de89fd9SPi-Hsun Shih msleep(EC_REBOOT_DELAY_MS);
1442de89fd9SPi-Hsun Shih
1452de89fd9SPi-Hsun Shih return ret;
1462de89fd9SPi-Hsun Shih }
1472de89fd9SPi-Hsun Shih
1482de89fd9SPi-Hsun Shih static void
cros_ec_rpmsg_host_event_function(struct work_struct * host_event_work)1492de89fd9SPi-Hsun Shih cros_ec_rpmsg_host_event_function(struct work_struct *host_event_work)
1502de89fd9SPi-Hsun Shih {
1512de89fd9SPi-Hsun Shih struct cros_ec_rpmsg *ec_rpmsg = container_of(host_event_work,
1522de89fd9SPi-Hsun Shih struct cros_ec_rpmsg,
1532de89fd9SPi-Hsun Shih host_event_work);
1542de89fd9SPi-Hsun Shih
15524c69043SGwendal Grignou cros_ec_irq_thread(0, dev_get_drvdata(&ec_rpmsg->rpdev->dev));
1562de89fd9SPi-Hsun Shih }
1572de89fd9SPi-Hsun Shih
cros_ec_rpmsg_callback(struct rpmsg_device * rpdev,void * data,int len,void * priv,u32 src)1582de89fd9SPi-Hsun Shih static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
1592de89fd9SPi-Hsun Shih int len, void *priv, u32 src)
1602de89fd9SPi-Hsun Shih {
1612de89fd9SPi-Hsun Shih struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev);
1622de89fd9SPi-Hsun Shih struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
1632de89fd9SPi-Hsun Shih struct cros_ec_rpmsg_response *resp;
1642de89fd9SPi-Hsun Shih
1652de89fd9SPi-Hsun Shih if (!len) {
1662de89fd9SPi-Hsun Shih dev_warn(ec_dev->dev, "rpmsg received empty response");
1672de89fd9SPi-Hsun Shih return -EINVAL;
1682de89fd9SPi-Hsun Shih }
1692de89fd9SPi-Hsun Shih
1702de89fd9SPi-Hsun Shih resp = data;
1712de89fd9SPi-Hsun Shih len -= offsetof(struct cros_ec_rpmsg_response, data);
1722de89fd9SPi-Hsun Shih if (resp->type == HOST_COMMAND_MARK) {
1732de89fd9SPi-Hsun Shih if (len > ec_dev->din_size) {
1742de89fd9SPi-Hsun Shih dev_warn(ec_dev->dev,
1752de89fd9SPi-Hsun Shih "received length %d > din_size %d, truncating",
1762de89fd9SPi-Hsun Shih len, ec_dev->din_size);
1772de89fd9SPi-Hsun Shih len = ec_dev->din_size;
1782de89fd9SPi-Hsun Shih }
1792de89fd9SPi-Hsun Shih
1802de89fd9SPi-Hsun Shih memcpy(ec_dev->din, resp->data, len);
1812de89fd9SPi-Hsun Shih complete(&ec_rpmsg->xfer_ack);
1822de89fd9SPi-Hsun Shih } else if (resp->type == HOST_EVENT_MARK) {
183f775ac78SPi-Hsun Shih /*
184f775ac78SPi-Hsun Shih * If the host event is sent before cros_ec_register is
185f775ac78SPi-Hsun Shih * finished, queue the host event.
186f775ac78SPi-Hsun Shih */
187f775ac78SPi-Hsun Shih if (ec_rpmsg->probe_done)
1882de89fd9SPi-Hsun Shih schedule_work(&ec_rpmsg->host_event_work);
189f775ac78SPi-Hsun Shih else
190f775ac78SPi-Hsun Shih ec_rpmsg->has_pending_host_event = true;
1912de89fd9SPi-Hsun Shih } else {
1922de89fd9SPi-Hsun Shih dev_warn(ec_dev->dev, "rpmsg received invalid type = %d",
1932de89fd9SPi-Hsun Shih resp->type);
1942de89fd9SPi-Hsun Shih return -EINVAL;
1952de89fd9SPi-Hsun Shih }
1962de89fd9SPi-Hsun Shih
1972de89fd9SPi-Hsun Shih return 0;
1982de89fd9SPi-Hsun Shih }
1992de89fd9SPi-Hsun Shih
20071cddb70SPi-Hsun Shih static struct rpmsg_endpoint *
cros_ec_rpmsg_create_ept(struct rpmsg_device * rpdev)20171cddb70SPi-Hsun Shih cros_ec_rpmsg_create_ept(struct rpmsg_device *rpdev)
20271cddb70SPi-Hsun Shih {
20371cddb70SPi-Hsun Shih struct rpmsg_channel_info chinfo = {};
20471cddb70SPi-Hsun Shih
20571cddb70SPi-Hsun Shih strscpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
20671cddb70SPi-Hsun Shih chinfo.src = rpdev->src;
20771cddb70SPi-Hsun Shih chinfo.dst = RPMSG_ADDR_ANY;
20871cddb70SPi-Hsun Shih
20971cddb70SPi-Hsun Shih return rpmsg_create_ept(rpdev, cros_ec_rpmsg_callback, NULL, chinfo);
21071cddb70SPi-Hsun Shih }
21171cddb70SPi-Hsun Shih
cros_ec_rpmsg_probe(struct rpmsg_device * rpdev)2122de89fd9SPi-Hsun Shih static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev)
2132de89fd9SPi-Hsun Shih {
2142de89fd9SPi-Hsun Shih struct device *dev = &rpdev->dev;
2152de89fd9SPi-Hsun Shih struct cros_ec_rpmsg *ec_rpmsg;
2162de89fd9SPi-Hsun Shih struct cros_ec_device *ec_dev;
21771cddb70SPi-Hsun Shih int ret;
2182de89fd9SPi-Hsun Shih
2192de89fd9SPi-Hsun Shih ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
2202de89fd9SPi-Hsun Shih if (!ec_dev)
2212de89fd9SPi-Hsun Shih return -ENOMEM;
2222de89fd9SPi-Hsun Shih
2232de89fd9SPi-Hsun Shih ec_rpmsg = devm_kzalloc(dev, sizeof(*ec_rpmsg), GFP_KERNEL);
2242de89fd9SPi-Hsun Shih if (!ec_rpmsg)
2252de89fd9SPi-Hsun Shih return -ENOMEM;
2262de89fd9SPi-Hsun Shih
2272de89fd9SPi-Hsun Shih ec_dev->dev = dev;
2282de89fd9SPi-Hsun Shih ec_dev->priv = ec_rpmsg;
2292de89fd9SPi-Hsun Shih ec_dev->cmd_xfer = cros_ec_cmd_xfer_rpmsg;
2302de89fd9SPi-Hsun Shih ec_dev->pkt_xfer = cros_ec_pkt_xfer_rpmsg;
2312de89fd9SPi-Hsun Shih ec_dev->phys_name = dev_name(&rpdev->dev);
2322de89fd9SPi-Hsun Shih ec_dev->din_size = sizeof(struct ec_host_response) +
2332de89fd9SPi-Hsun Shih sizeof(struct ec_response_get_protocol_info);
2342de89fd9SPi-Hsun Shih ec_dev->dout_size = sizeof(struct ec_host_request);
2352de89fd9SPi-Hsun Shih dev_set_drvdata(dev, ec_dev);
2362de89fd9SPi-Hsun Shih
2372de89fd9SPi-Hsun Shih ec_rpmsg->rpdev = rpdev;
2382de89fd9SPi-Hsun Shih init_completion(&ec_rpmsg->xfer_ack);
2392de89fd9SPi-Hsun Shih INIT_WORK(&ec_rpmsg->host_event_work,
2402de89fd9SPi-Hsun Shih cros_ec_rpmsg_host_event_function);
2412de89fd9SPi-Hsun Shih
24271cddb70SPi-Hsun Shih ec_rpmsg->ept = cros_ec_rpmsg_create_ept(rpdev);
24371cddb70SPi-Hsun Shih if (!ec_rpmsg->ept)
24471cddb70SPi-Hsun Shih return -ENOMEM;
24571cddb70SPi-Hsun Shih
24671cddb70SPi-Hsun Shih ret = cros_ec_register(ec_dev);
24771cddb70SPi-Hsun Shih if (ret < 0) {
24871cddb70SPi-Hsun Shih rpmsg_destroy_ept(ec_rpmsg->ept);
24971cddb70SPi-Hsun Shih cancel_work_sync(&ec_rpmsg->host_event_work);
25071cddb70SPi-Hsun Shih return ret;
25171cddb70SPi-Hsun Shih }
25271cddb70SPi-Hsun Shih
253f775ac78SPi-Hsun Shih ec_rpmsg->probe_done = true;
254f775ac78SPi-Hsun Shih
255f775ac78SPi-Hsun Shih if (ec_rpmsg->has_pending_host_event)
256f775ac78SPi-Hsun Shih schedule_work(&ec_rpmsg->host_event_work);
257f775ac78SPi-Hsun Shih
25871cddb70SPi-Hsun Shih return 0;
2592de89fd9SPi-Hsun Shih }
2602de89fd9SPi-Hsun Shih
cros_ec_rpmsg_remove(struct rpmsg_device * rpdev)2612de89fd9SPi-Hsun Shih static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev)
2622de89fd9SPi-Hsun Shih {
2632de89fd9SPi-Hsun Shih struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev);
2642de89fd9SPi-Hsun Shih struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
2652de89fd9SPi-Hsun Shih
2667aa703bbSEnric Balletbo i Serra cros_ec_unregister(ec_dev);
26771cddb70SPi-Hsun Shih rpmsg_destroy_ept(ec_rpmsg->ept);
2682de89fd9SPi-Hsun Shih cancel_work_sync(&ec_rpmsg->host_event_work);
2692de89fd9SPi-Hsun Shih }
2702de89fd9SPi-Hsun Shih
271058bf149SYilun Lin #ifdef CONFIG_PM_SLEEP
cros_ec_rpmsg_suspend(struct device * dev)272058bf149SYilun Lin static int cros_ec_rpmsg_suspend(struct device *dev)
273058bf149SYilun Lin {
274058bf149SYilun Lin struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
275058bf149SYilun Lin
276058bf149SYilun Lin return cros_ec_suspend(ec_dev);
277058bf149SYilun Lin }
278058bf149SYilun Lin
cros_ec_rpmsg_resume(struct device * dev)279058bf149SYilun Lin static int cros_ec_rpmsg_resume(struct device *dev)
280058bf149SYilun Lin {
281058bf149SYilun Lin struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
282058bf149SYilun Lin
283058bf149SYilun Lin return cros_ec_resume(ec_dev);
284058bf149SYilun Lin }
285058bf149SYilun Lin #endif
286058bf149SYilun Lin
287058bf149SYilun Lin static SIMPLE_DEV_PM_OPS(cros_ec_rpmsg_pm_ops, cros_ec_rpmsg_suspend,
288058bf149SYilun Lin cros_ec_rpmsg_resume);
289058bf149SYilun Lin
2902de89fd9SPi-Hsun Shih static const struct of_device_id cros_ec_rpmsg_of_match[] = {
2912de89fd9SPi-Hsun Shih { .compatible = "google,cros-ec-rpmsg", },
2922de89fd9SPi-Hsun Shih { }
2932de89fd9SPi-Hsun Shih };
2942de89fd9SPi-Hsun Shih MODULE_DEVICE_TABLE(of, cros_ec_rpmsg_of_match);
2952de89fd9SPi-Hsun Shih
2962de89fd9SPi-Hsun Shih static struct rpmsg_driver cros_ec_driver_rpmsg = {
2972de89fd9SPi-Hsun Shih .drv = {
2982de89fd9SPi-Hsun Shih .name = "cros-ec-rpmsg",
2992de89fd9SPi-Hsun Shih .of_match_table = cros_ec_rpmsg_of_match,
300058bf149SYilun Lin .pm = &cros_ec_rpmsg_pm_ops,
3012de89fd9SPi-Hsun Shih },
3022de89fd9SPi-Hsun Shih .probe = cros_ec_rpmsg_probe,
3032de89fd9SPi-Hsun Shih .remove = cros_ec_rpmsg_remove,
3042de89fd9SPi-Hsun Shih };
3052de89fd9SPi-Hsun Shih
3062de89fd9SPi-Hsun Shih module_rpmsg_driver(cros_ec_driver_rpmsg);
3072de89fd9SPi-Hsun Shih
3082de89fd9SPi-Hsun Shih MODULE_LICENSE("GPL v2");
3092de89fd9SPi-Hsun Shih MODULE_DESCRIPTION("ChromeOS EC multi function device (rpmsg)");
310