drivers/soc/qcom/smd-rpm.c

   1 /*
   2  * Copyright (c) 2015, Sony Mobile Communications AB.
   3  * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 and
   7  * only version 2 as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/io.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/slab.h>
  21
  22 #include <linux/soc/qcom/smd.h>
  23 #include <linux/soc/qcom/smd-rpm.h>
  24
  25 #define RPM_REQUEST_TIMEOUT     (5 * HZ)
  26
  27 /**
  28  * struct qcom_smd_rpm - state of the rpm device driver
  29  * @rpm_channel:        reference to the smd channel
  30  * @ack:                completion for acks
  31  * @lock:               mutual exclusion around the send/complete pair
  32  * @ack_status:         result of the rpm request
  33  */
  34 struct qcom_smd_rpm {
  35         struct qcom_smd_channel *rpm_channel;
  36         struct device *dev;
  37
  38         struct completion ack;
  39         struct mutex lock;
  40         int ack_status;
  41 };
  42
  43 /**
  44  * struct qcom_rpm_header - header for all rpm requests and responses
  45  * @service_type:       identifier of the service
  46  * @length:             length of the payload
  47  */
  48 struct qcom_rpm_header {
  49         __le32 service_type;
  50         __le32 length;
  51 };
  52
  53 /**
  54  * struct qcom_rpm_request - request message to the rpm
  55  * @msg_id:     identifier of the outgoing message
  56  * @flags:      active/sleep state flags
  57  * @type:       resource type
  58  * @id:         resource id
  59  * @data_len:   length of the payload following this header
  60  */
  61 struct qcom_rpm_request {
  62         __le32 msg_id;
  63         __le32 flags;
  64         __le32 type;
  65         __le32 id;
  66         __le32 data_len;
  67 };
  68
  69 /**
  70  * struct qcom_rpm_message - response message from the rpm
  71  * @msg_type:   indicator of the type of message
  72  * @length:     the size of this message, including the message header
  73  * @msg_id:     message id
  74  * @message:    textual message from the rpm
  75  *
  76  * Multiple of these messages can be stacked in an rpm message.
  77  */
  78 struct qcom_rpm_message {
  79         __le32 msg_type;
  80         __le32 length;
  81         union {
  82                 __le32 msg_id;
  83                 u8 message[0];
  84         };
  85 };
  86
  87 #define RPM_SERVICE_TYPE_REQUEST        0x00716572 /* "req\0" */
  88
  89 #define RPM_MSG_TYPE_ERR                0x00727265 /* "err\0" */
  90 #define RPM_MSG_TYPE_MSG_ID             0x2367736d /* "msg#" */
  91
  92 /**
  93  * qcom_rpm_smd_write - write @buf to @type:@id
  94  * @rpm:        rpm handle
  95  * @type:       resource type
  96  * @id:         resource identifier
  97  * @buf:        the data to be written
  98  * @count:      number of bytes in @buf
  99  */
 100 int qcom_rpm_smd_write(struct qcom_smd_rpm *rpm,
 101                        int state,
 102                        u32 type, u32 id,
 103                        void *buf,
 104                        size_t count)
 105 {
 106         static unsigned msg_id = 1;
 107         int left;
 108         int ret;
 109         struct {
 110                 struct qcom_rpm_header hdr;
 111                 struct qcom_rpm_request req;
 112                 u8 payload[];
 113         } *pkt;
 114         size_t size = sizeof(*pkt) + count;
 115
 116         /* SMD packets to the RPM may not exceed 256 bytes */
 117         if (WARN_ON(size >= 256))
 118                 return -EINVAL;
 119
 120         pkt = kmalloc(size, GFP_KERNEL);
 121         if (!pkt)
 122                 return -ENOMEM;
 123
 124         mutex_lock(&rpm->lock);
 125
 126         pkt->hdr.service_type = cpu_to_le32(RPM_SERVICE_TYPE_REQUEST);
 127         pkt->hdr.length = cpu_to_le32(sizeof(struct qcom_rpm_request) + count);
 128
 129         pkt->req.msg_id = cpu_to_le32(msg_id++);
 130         pkt->req.flags = cpu_to_le32(state);
 131         pkt->req.type = cpu_to_le32(type);
 132         pkt->req.id = cpu_to_le32(id);
 133         pkt->req.data_len = cpu_to_le32(count);
 134         memcpy(pkt->payload, buf, count);
 135
 136         ret = qcom_smd_send(rpm->rpm_channel, pkt, size);
 137         if (ret)
 138                 goto out;
 139
 140         left = wait_for_completion_timeout(&rpm->ack, RPM_REQUEST_TIMEOUT);
 141         if (!left)
 142                 ret = -ETIMEDOUT;
 143         else
 144                 ret = rpm->ack_status;
 145
 146 out:
 147         kfree(pkt);
 148         mutex_unlock(&rpm->lock);
 149         return ret;
 150 }
 151 EXPORT_SYMBOL(qcom_rpm_smd_write);
 152
 153 static int qcom_smd_rpm_callback(struct qcom_smd_channel *channel,
 154                                  const void *data,
 155                                  size_t count)
 156 {
 157         const struct qcom_rpm_header *hdr = data;
 158         size_t hdr_length = le32_to_cpu(hdr->length);
 159         const struct qcom_rpm_message *msg;
 160         struct qcom_smd_rpm *rpm = qcom_smd_get_drvdata(channel);
 161         const u8 *buf = data + sizeof(struct qcom_rpm_header);
 162         const u8 *end = buf + hdr_length;
 163         char msgbuf[32];
 164         int status = 0;
 165         u32 len, msg_length;
 166
 167         if (le32_to_cpu(hdr->service_type) != RPM_SERVICE_TYPE_REQUEST ||
 168             hdr_length < sizeof(struct qcom_rpm_message)) {
 169                 dev_err(rpm->dev, "invalid request\n");
 170                 return 0;
 171         }
 172
 173         while (buf < end) {
 174                 msg = (struct qcom_rpm_message *)buf;
 175                 msg_length = le32_to_cpu(msg->length);
 176                 switch (le32_to_cpu(msg->msg_type)) {
 177                 case RPM_MSG_TYPE_MSG_ID:
 178                         break;
 179                 case RPM_MSG_TYPE_ERR:
 180                         len = min_t(u32, ALIGN(msg_length, 4), sizeof(msgbuf));
 181                         memcpy_fromio(msgbuf, msg->message, len);
 182                         msgbuf[len - 1] = 0;
 183
 184                         if (!strcmp(msgbuf, "resource does not exist"))
 185                                 status = -ENXIO;
 186                         else
 187                                 status = -EINVAL;
 188                         break;
 189                 }
 190
 191                 buf = PTR_ALIGN(buf + 2 * sizeof(u32) + msg_length, 4);
 192         }
 193
 194         rpm->ack_status = status;
 195         complete(&rpm->ack);
 196         return 0;
 197 }
 198
 199 static int qcom_smd_rpm_probe(struct qcom_smd_device *sdev)
 200 {
 201         struct qcom_smd_rpm *rpm;
 202
 203         rpm = devm_kzalloc(&sdev->dev, sizeof(*rpm), GFP_KERNEL);
 204         if (!rpm)
 205                 return -ENOMEM;
 206
 207         mutex_init(&rpm->lock);
 208         init_completion(&rpm->ack);
 209
 210         rpm->dev = &sdev->dev;
 211         rpm->rpm_channel = sdev->channel;
 212         qcom_smd_set_drvdata(sdev->channel, rpm);
 213
 214         dev_set_drvdata(&sdev->dev, rpm);
 215
 216         return of_platform_populate(sdev->dev.of_node, NULL, NULL, &sdev->dev);
 217 }
 218
 219 static void qcom_smd_rpm_remove(struct qcom_smd_device *sdev)
 220 {
 221         of_platform_depopulate(&sdev->dev);
 222 }
 223
 224 static const struct of_device_id qcom_smd_rpm_of_match[] = {
 225         { .compatible = "qcom,rpm-apq8084" },
 226         { .compatible = "qcom,rpm-msm8916" },
 227         { .compatible = "qcom,rpm-msm8974" },
 228         {}
 229 };
 230 MODULE_DEVICE_TABLE(of, qcom_smd_rpm_of_match);
 231
 232 static struct qcom_smd_driver qcom_smd_rpm_driver = {
 233         .probe = qcom_smd_rpm_probe,
 234         .remove = qcom_smd_rpm_remove,
 235         .callback = qcom_smd_rpm_callback,
 236         .driver  = {
 237                 .name  = "qcom_smd_rpm",
 238                 .owner = THIS_MODULE,
 239                 .of_match_table = qcom_smd_rpm_of_match,
 240         },
 241 };
 242
 243 static int __init qcom_smd_rpm_init(void)
 244 {
 245         return qcom_smd_driver_register(&qcom_smd_rpm_driver);
 246 }
 247 arch_initcall(qcom_smd_rpm_init);
 248
 249 static void __exit qcom_smd_rpm_exit(void)
 250 {
 251         qcom_smd_driver_unregister(&qcom_smd_rpm_driver);
 252 }
 253 module_exit(qcom_smd_rpm_exit);
 254
 255 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
 256 MODULE_DESCRIPTION("Qualcomm SMD backed RPM driver");
 257 MODULE_LICENSE("GPL v2");