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  * @icc:                interconnect proxy device
  23  * @ack:                completion for acks
  24  * @lock:               mutual exclusion around the send/complete pair
  25  * @ack_status:         result of the rpm request
  26  */
  27 struct qcom_smd_rpm {
  28         struct rpmsg_endpoint *rpm_channel;
  29         struct platform_device *icc;
  30         struct device *dev;
  31
  32         struct completion ack;
  33         struct mutex lock;
  34         int ack_status;
  35 };
  36
  37 /**
  38  * struct qcom_rpm_header - header for all rpm requests and responses
  39  * @service_type:       identifier of the service
  40  * @length:             length of the payload
  41  */
  42 struct qcom_rpm_header {
  43         __le32 service_type;
  44         __le32 length;
  45 };
  46
  47 /**
  48  * struct qcom_rpm_request - request message to the rpm
  49  * @msg_id:     identifier of the outgoing message
  50  * @flags:      active/sleep state flags
  51  * @type:       resource type
  52  * @id:         resource id
  53  * @data_len:   length of the payload following this header
  54  */
  55 struct qcom_rpm_request {
  56         __le32 msg_id;
  57         __le32 flags;
  58         __le32 type;
  59         __le32 id;
  60         __le32 data_len;
  61 };
  62
  63 /**
  64  * struct qcom_rpm_message - response message from the rpm
  65  * @msg_type:   indicator of the type of message
  66  * @length:     the size of this message, including the message header
  67  * @msg_id:     message id
  68  * @message:    textual message from the rpm
  69  *
  70  * Multiple of these messages can be stacked in an rpm message.
  71  */
  72 struct qcom_rpm_message {
  73         __le32 msg_type;
  74         __le32 length;
  75         union {
  76                 __le32 msg_id;
  77                 u8 message[0];
  78         };
  79 };
  80
  81 #define RPM_SERVICE_TYPE_REQUEST        0x00716572 /* "req\0" */
  82
  83 #define RPM_MSG_TYPE_ERR                0x00727265 /* "err\0" */
  84 #define RPM_MSG_TYPE_MSG_ID             0x2367736d /* "msg#" */
  85
  86 /**
  87  * qcom_rpm_smd_write - write @buf to @type:@id
  88  * @rpm:        rpm handle
  89  * @type:       resource type
  90  * @id:         resource identifier
  91  * @buf:        the data to be written
  92  * @count:      number of bytes in @buf
  93  */
  94 int qcom_rpm_smd_write(struct qcom_smd_rpm *rpm,
  95                        int state,
  96                        u32 type, u32 id,
  97                        void *buf,
  98                        size_t count)
  99 {
 100         static unsigned msg_id = 1;
 101         int left;
 102         int ret;
 103         struct {
 104                 struct qcom_rpm_header hdr;
 105                 struct qcom_rpm_request req;
 106                 u8 payload[];
 107         } *pkt;
 108         size_t size = sizeof(*pkt) + count;
 109
 110         /* SMD packets to the RPM may not exceed 256 bytes */
 111         if (WARN_ON(size >= 256))
 112                 return -EINVAL;
 113
 114         pkt = kmalloc(size, GFP_KERNEL);
 115         if (!pkt)
 116                 return -ENOMEM;
 117
 118         mutex_lock(&rpm->lock);
 119
 120         pkt->hdr.service_type = cpu_to_le32(RPM_SERVICE_TYPE_REQUEST);
 121         pkt->hdr.length = cpu_to_le32(sizeof(struct qcom_rpm_request) + count);
 122
 123         pkt->req.msg_id = cpu_to_le32(msg_id++);
 124         pkt->req.flags = cpu_to_le32(state);
 125         pkt->req.type = cpu_to_le32(type);
 126         pkt->req.id = cpu_to_le32(id);
 127         pkt->req.data_len = cpu_to_le32(count);
 128         memcpy(pkt->payload, buf, count);
 129
 130         ret = rpmsg_send(rpm->rpm_channel, pkt, size);
 131         if (ret)
 132                 goto out;
 133
 134         left = wait_for_completion_timeout(&rpm->ack, RPM_REQUEST_TIMEOUT);
 135         if (!left)
 136                 ret = -ETIMEDOUT;
 137         else
 138                 ret = rpm->ack_status;
 139
 140 out:
 141         kfree(pkt);
 142         mutex_unlock(&rpm->lock);
 143         return ret;
 144 }
 145 EXPORT_SYMBOL(qcom_rpm_smd_write);
 146
 147 static int qcom_smd_rpm_callback(struct rpmsg_device *rpdev,
 148                                  void *data,
 149                                  int count,
 150                                  void *priv,
 151                                  u32 addr)
 152 {
 153         const struct qcom_rpm_header *hdr = data;
 154         size_t hdr_length = le32_to_cpu(hdr->length);
 155         const struct qcom_rpm_message *msg;
 156         struct qcom_smd_rpm *rpm = dev_get_drvdata(&rpdev->dev);
 157         const u8 *buf = data + sizeof(struct qcom_rpm_header);
 158         const u8 *end = buf + hdr_length;
 159         char msgbuf[32];
 160         int status = 0;
 161         u32 len, msg_length;
 162
 163         if (le32_to_cpu(hdr->service_type) != RPM_SERVICE_TYPE_REQUEST ||
 164             hdr_length < sizeof(struct qcom_rpm_message)) {
 165                 dev_err(rpm->dev, "invalid request\n");
 166                 return 0;
 167         }
 168
 169         while (buf < end) {
 170                 msg = (struct qcom_rpm_message *)buf;
 171                 msg_length = le32_to_cpu(msg->length);
 172                 switch (le32_to_cpu(msg->msg_type)) {
 173                 case RPM_MSG_TYPE_MSG_ID:
 174                         break;
 175                 case RPM_MSG_TYPE_ERR:
 176                         len = min_t(u32, ALIGN(msg_length, 4), sizeof(msgbuf));
 177                         memcpy_fromio(msgbuf, msg->message, len);
 178                         msgbuf[len - 1] = 0;
 179
 180                         if (!strcmp(msgbuf, "resource does not exist"))
 181                                 status = -ENXIO;
 182                         else
 183                                 status = -EINVAL;
 184                         break;
 185                 }
 186
 187                 buf = PTR_ALIGN(buf + 2 * sizeof(u32) + msg_length, 4);
 188         }
 189
 190         rpm->ack_status = status;
 191         complete(&rpm->ack);
 192         return 0;
 193 }
 194
 195 static int qcom_smd_rpm_probe(struct rpmsg_device *rpdev)
 196 {
 197         struct qcom_smd_rpm *rpm;
 198         int ret;
 199
 200         rpm = devm_kzalloc(&rpdev->dev, sizeof(*rpm), GFP_KERNEL);
 201         if (!rpm)
 202                 return -ENOMEM;
 203
 204         mutex_init(&rpm->lock);
 205         init_completion(&rpm->ack);
 206
 207         rpm->dev = &rpdev->dev;
 208         rpm->rpm_channel = rpdev->ept;
 209         dev_set_drvdata(&rpdev->dev, rpm);
 210
 211         rpm->icc = platform_device_register_data(&rpdev->dev, "icc_smd_rpm", -1,
 212                                                  NULL, 0);
 213         if (IS_ERR(rpm->icc))
 214                 return PTR_ERR(rpm->icc);
 215
 216         ret = of_platform_populate(rpdev->dev.of_node, NULL, NULL, &rpdev->dev);
 217         if (ret)
 218                 platform_device_unregister(rpm->icc);
 219
 220         return ret;
 221 }
 222
 223 static void qcom_smd_rpm_remove(struct rpmsg_device *rpdev)
 224 {
 225         struct qcom_smd_rpm *rpm = dev_get_drvdata(&rpdev->dev);
 226
 227         platform_device_unregister(rpm->icc);
 228         of_platform_depopulate(&rpdev->dev);
 229 }
 230
 231 static const struct of_device_id qcom_smd_rpm_of_match[] = {
 232         { .compatible = "qcom,rpm-apq8084" },
 233         { .compatible = "qcom,rpm-msm8916" },
 234         { .compatible = "qcom,rpm-msm8974" },
 235         { .compatible = "qcom,rpm-msm8976" },
 236         { .compatible = "qcom,rpm-msm8996" },
 237         { .compatible = "qcom,rpm-msm8998" },
 238         { .compatible = "qcom,rpm-sdm660" },
 239         { .compatible = "qcom,rpm-qcs404" },
 240         {}
 241 };
 242 MODULE_DEVICE_TABLE(of, qcom_smd_rpm_of_match);
 243
 244 static struct rpmsg_driver qcom_smd_rpm_driver = {
 245         .probe = qcom_smd_rpm_probe,
 246         .remove = qcom_smd_rpm_remove,
 247         .callback = qcom_smd_rpm_callback,
 248         .drv  = {
 249                 .name  = "qcom_smd_rpm",
 250                 .of_match_table = qcom_smd_rpm_of_match,
 251         },
 252 };
 253
 254 static int __init qcom_smd_rpm_init(void)
 255 {
 256         return register_rpmsg_driver(&qcom_smd_rpm_driver);
 257 }
 258 arch_initcall(qcom_smd_rpm_init);
 259
 260 static void __exit qcom_smd_rpm_exit(void)
 261 {
 262         unregister_rpmsg_driver(&qcom_smd_rpm_driver);
 263 }
 264 module_exit(qcom_smd_rpm_exit);
 265
 266 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
 267 MODULE_DESCRIPTION("Qualcomm SMD backed RPM driver");
 268 MODULE_LICENSE("GPL v2");