drivers/soc/qcom/smd-rpm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015, Sony Mobile Communications AB.
   4  * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/platform_device.h>
   9 #include <linux/of_platform.h>
  10 #include <linux/io.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/slab.h>
  13
  14 #include <linux/rpmsg.h>
  15 #include <linux/soc/qcom/smd-rpm.h>
  16
  17 #define RPM_REQUEST_TIMEOUT     (5 * HZ)
  18
  19 /**
  20  * struct qcom_smd_rpm - state of the rpm device driver
  21  * @rpm_channel:        reference to the smd channel
  22  * @ack:                completion for acks
  23  * @lock:               mutual exclusion around the send/complete pair
  24  * @ack_status:         result of the rpm request
  25  */
  26 struct qcom_smd_rpm {
  27         struct rpmsg_endpoint *rpm_channel;
  28         struct device *dev;
  29
  30         struct completion ack;
  31         struct mutex lock;
  32         int ack_status;
  33 };
  34
  35 /**
  36  * struct qcom_rpm_header - header for all rpm requests and responses
  37  * @service_type:       identifier of the service
  38  * @length:             length of the payload
  39  */
  40 struct qcom_rpm_header {
  41         __le32 service_type;
  42         __le32 length;
  43 };
  44
  45 /**
  46  * struct qcom_rpm_request - request message to the rpm
  47  * @msg_id:     identifier of the outgoing message
  48  * @flags:      active/sleep state flags
  49  * @type:       resource type
  50  * @id:         resource id
  51  * @data_len:   length of the payload following this header
  52  */
  53 struct qcom_rpm_request {
  54         __le32 msg_id;
  55         __le32 flags;
  56         __le32 type;
  57         __le32 id;
  58         __le32 data_len;
  59 };
  60
  61 /**
  62  * struct qcom_rpm_message - response message from the rpm
  63  * @msg_type:   indicator of the type of message
  64  * @length:     the size of this message, including the message header
  65  * @msg_id:     message id
  66  * @message:    textual message from the rpm
  67  *
  68  * Multiple of these messages can be stacked in an rpm message.
  69  */
  70 struct qcom_rpm_message {
  71         __le32 msg_type;
  72         __le32 length;
  73         union {
  74                 __le32 msg_id;
  75                 u8 message[0];
  76         };
  77 };
  78
  79 #define RPM_SERVICE_TYPE_REQUEST        0x00716572 /* "req\0" */
  80
  81 #define RPM_MSG_TYPE_ERR                0x00727265 /* "err\0" */
  82 #define RPM_MSG_TYPE_MSG_ID             0x2367736d /* "msg#" */
  83
  84 /**
  85  * qcom_rpm_smd_write - write @buf to @type:@id
  86  * @rpm:        rpm handle
  87  * @type:       resource type
  88  * @id:         resource identifier
  89  * @buf:        the data to be written
  90  * @count:      number of bytes in @buf
  91  */
  92 int qcom_rpm_smd_write(struct qcom_smd_rpm *rpm,
  93                        int state,
  94                        u32 type, u32 id,
  95                        void *buf,
  96                        size_t count)
  97 {
  98         static unsigned msg_id = 1;
  99         int left;
 100         int ret;
 101         struct {
 102                 struct qcom_rpm_header hdr;
 103                 struct qcom_rpm_request req;
 104                 u8 payload[];
 105         } *pkt;
 106         size_t size = sizeof(*pkt) + count;
 107
 108         /* SMD packets to the RPM may not exceed 256 bytes */
 109         if (WARN_ON(size >= 256))
 110                 return -EINVAL;
 111
 112         pkt = kmalloc(size, GFP_KERNEL);
 113         if (!pkt)
 114                 return -ENOMEM;
 115
 116         mutex_lock(&rpm->lock);
 117
 118         pkt->hdr.service_type = cpu_to_le32(RPM_SERVICE_TYPE_REQUEST);
 119         pkt->hdr.length = cpu_to_le32(sizeof(struct qcom_rpm_request) + count);
 120
 121         pkt->req.msg_id = cpu_to_le32(msg_id++);
 122         pkt->req.flags = cpu_to_le32(state);
 123         pkt->req.type = cpu_to_le32(type);
 124         pkt->req.id = cpu_to_le32(id);
 125         pkt->req.data_len = cpu_to_le32(count);
 126         memcpy(pkt->payload, buf, count);
 127
 128         ret = rpmsg_send(rpm->rpm_channel, pkt, size);
 129         if (ret)
 130                 goto out;
 131
 132         left = wait_for_completion_timeout(&rpm->ack, RPM_REQUEST_TIMEOUT);
 133         if (!left)
 134                 ret = -ETIMEDOUT;
 135         else
 136                 ret = rpm->ack_status;
 137
 138 out:
 139         kfree(pkt);
 140         mutex_unlock(&rpm->lock);
 141         return ret;
 142 }
 143 EXPORT_SYMBOL(qcom_rpm_smd_write);
 144
 145 static int qcom_smd_rpm_callback(struct rpmsg_device *rpdev,
 146                                  void *data,
 147                                  int count,
 148                                  void *priv,
 149                                  u32 addr)
 150 {
 151         const struct qcom_rpm_header *hdr = data;
 152         size_t hdr_length = le32_to_cpu(hdr->length);
 153         const struct qcom_rpm_message *msg;
 154         struct qcom_smd_rpm *rpm = dev_get_drvdata(&rpdev->dev);
 155         const u8 *buf = data + sizeof(struct qcom_rpm_header);
 156         const u8 *end = buf + hdr_length;
 157         char msgbuf[32];
 158         int status = 0;
 159         u32 len, msg_length;
 160
 161         if (le32_to_cpu(hdr->service_type) != RPM_SERVICE_TYPE_REQUEST ||
 162             hdr_length < sizeof(struct qcom_rpm_message)) {
 163                 dev_err(rpm->dev, "invalid request\n");
 164                 return 0;
 165         }
 166
 167         while (buf < end) {
 168                 msg = (struct qcom_rpm_message *)buf;
 169                 msg_length = le32_to_cpu(msg->length);
 170                 switch (le32_to_cpu(msg->msg_type)) {
 171                 case RPM_MSG_TYPE_MSG_ID:
 172                         break;
 173                 case RPM_MSG_TYPE_ERR:
 174                         len = min_t(u32, ALIGN(msg_length, 4), sizeof(msgbuf));
 175                         memcpy_fromio(msgbuf, msg->message, len);
 176                         msgbuf[len - 1] = 0;
 177
 178                         if (!strcmp(msgbuf, "resource does not exist"))
 179                                 status = -ENXIO;
 180                         else
 181                                 status = -EINVAL;
 182                         break;
 183                 }
 184
 185                 buf = PTR_ALIGN(buf + 2 * sizeof(u32) + msg_length, 4);
 186         }
 187
 188         rpm->ack_status = status;
 189         complete(&rpm->ack);
 190         return 0;
 191 }
 192
 193 static int qcom_smd_rpm_probe(struct rpmsg_device *rpdev)
 194 {
 195         struct qcom_smd_rpm *rpm;
 196
 197         rpm = devm_kzalloc(&rpdev->dev, sizeof(*rpm), GFP_KERNEL);
 198         if (!rpm)
 199                 return -ENOMEM;
 200
 201         mutex_init(&rpm->lock);
 202         init_completion(&rpm->ack);
 203
 204         rpm->dev = &rpdev->dev;
 205         rpm->rpm_channel = rpdev->ept;
 206         dev_set_drvdata(&rpdev->dev, rpm);
 207
 208         return of_platform_populate(rpdev->dev.of_node, NULL, NULL, &rpdev->dev);
 209 }
 210
 211 static void qcom_smd_rpm_remove(struct rpmsg_device *rpdev)
 212 {
 213         of_platform_depopulate(&rpdev->dev);
 214 }
 215
 216 static const struct of_device_id qcom_smd_rpm_of_match[] = {
 217         { .compatible = "qcom,rpm-apq8084" },
 218         { .compatible = "qcom,rpm-msm8916" },
 219         { .compatible = "qcom,rpm-msm8974" },
 220         { .compatible = "qcom,rpm-msm8996" },
 221         { .compatible = "qcom,rpm-msm8998" },
 222         { .compatible = "qcom,rpm-sdm660" },
 223         { .compatible = "qcom,rpm-qcs404" },
 224         {}
 225 };
 226 MODULE_DEVICE_TABLE(of, qcom_smd_rpm_of_match);
 227
 228 static struct rpmsg_driver qcom_smd_rpm_driver = {
 229         .probe = qcom_smd_rpm_probe,
 230         .remove = qcom_smd_rpm_remove,
 231         .callback = qcom_smd_rpm_callback,
 232         .drv  = {
 233                 .name  = "qcom_smd_rpm",
 234                 .of_match_table = qcom_smd_rpm_of_match,
 235         },
 236 };
 237
 238 static int __init qcom_smd_rpm_init(void)
 239 {
 240         return register_rpmsg_driver(&qcom_smd_rpm_driver);
 241 }
 242 arch_initcall(qcom_smd_rpm_init);
 243
 244 static void __exit qcom_smd_rpm_exit(void)
 245 {
 246         unregister_rpmsg_driver(&qcom_smd_rpm_driver);
 247 }
 248 module_exit(qcom_smd_rpm_exit);
 249
 250 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
 251 MODULE_DESCRIPTION("Qualcomm SMD backed RPM driver");
 252 MODULE_LICENSE("GPL v2");