--- /dev/null
+/*
+ * Copyright (c) 2015, Sony Mobile Communications AB.
+ * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+
+#include <linux/soc/qcom/smd.h>
+#include <linux/soc/qcom/smd-rpm.h>
+
+#define RPM_REQUEST_TIMEOUT (5 * HZ)
+
+/**
+ * struct qcom_smd_rpm - state of the rpm device driver
+ * @rpm_channel: reference to the smd channel
+ * @ack: completion for acks
+ * @lock: mutual exclusion around the send/complete pair
+ * @ack_status: result of the rpm request
+ */
+struct qcom_smd_rpm {
+ struct qcom_smd_channel *rpm_channel;
+
+ struct completion ack;
+ struct mutex lock;
+ int ack_status;
+};
+
+/**
+ * struct qcom_rpm_header - header for all rpm requests and responses
+ * @service_type: identifier of the service
+ * @length: length of the payload
+ */
+struct qcom_rpm_header {
+ __le32 service_type;
+ __le32 length;
+};
+
+/**
+ * struct qcom_rpm_request - request message to the rpm
+ * @msg_id: identifier of the outgoing message
+ * @flags: active/sleep state flags
+ * @type: resource type
+ * @id: resource id
+ * @data_len: length of the payload following this header
+ */
+struct qcom_rpm_request {
+ __le32 msg_id;
+ __le32 flags;
+ __le32 type;
+ __le32 id;
+ __le32 data_len;
+};
+
+/**
+ * struct qcom_rpm_message - response message from the rpm
+ * @msg_type: indicator of the type of message
+ * @length: the size of this message, including the message header
+ * @msg_id: message id
+ * @message: textual message from the rpm
+ *
+ * Multiple of these messages can be stacked in an rpm message.
+ */
+struct qcom_rpm_message {
+ __le32 msg_type;
+ __le32 length;
+ union {
+ __le32 msg_id;
+ u8 message[0];
+ };
+};
+
+#define RPM_SERVICE_TYPE_REQUEST 0x00716572 /* "req\0" */
+
+#define RPM_MSG_TYPE_ERR 0x00727265 /* "err\0" */
+#define RPM_MSG_TYPE_MSG_ID 0x2367736d /* "msg#" */
+
+/**
+ * qcom_rpm_smd_write - write @buf to @type:@id
+ * @rpm: rpm handle
+ * @type: resource type
+ * @id: resource identifier
+ * @buf: the data to be written
+ * @count: number of bytes in @buf
+ */
+int qcom_rpm_smd_write(struct qcom_smd_rpm *rpm,
+ int state,
+ u32 type, u32 id,
+ void *buf,
+ size_t count)
+{
+ static unsigned msg_id = 1;
+ int left;
+ int ret;
+ struct {
+ struct qcom_rpm_header hdr;
+ struct qcom_rpm_request req;
+ u8 payload[];
+ } *pkt;
+ size_t size = sizeof(*pkt) + count;
+
+ /* SMD packets to the RPM may not exceed 256 bytes */
+ if (WARN_ON(size >= 256))
+ return -EINVAL;
+
+ pkt = kmalloc(size, GFP_KERNEL);
+ if (!pkt)
+ return -ENOMEM;
+
+ mutex_lock(&rpm->lock);
+
+ pkt->hdr.service_type = cpu_to_le32(RPM_SERVICE_TYPE_REQUEST);
+ pkt->hdr.length = cpu_to_le32(sizeof(struct qcom_rpm_request) + count);
+
+ pkt->req.msg_id = cpu_to_le32(msg_id++);
+ pkt->req.flags = cpu_to_le32(state);
+ pkt->req.type = cpu_to_le32(type);
+ pkt->req.id = cpu_to_le32(id);
+ pkt->req.data_len = cpu_to_le32(count);
+ memcpy(pkt->payload, buf, count);
+
+ ret = qcom_smd_send(rpm->rpm_channel, pkt, size);
+ if (ret)
+ goto out;
+
+ left = wait_for_completion_timeout(&rpm->ack, RPM_REQUEST_TIMEOUT);
+ if (!left)
+ ret = -ETIMEDOUT;
+ else
+ ret = rpm->ack_status;
+
+out:
+ kfree(pkt);
+ mutex_unlock(&rpm->lock);
+ return ret;
+}
+EXPORT_SYMBOL(qcom_rpm_smd_write);
+
+static int qcom_smd_rpm_callback(struct qcom_smd_device *qsdev,
+ const void *data,
+ size_t count)
+{
+ const struct qcom_rpm_header *hdr = data;
+ size_t hdr_length = le32_to_cpu(hdr->length);
+ const struct qcom_rpm_message *msg;
+ struct qcom_smd_rpm *rpm = dev_get_drvdata(&qsdev->dev);
+ const u8 *buf = data + sizeof(struct qcom_rpm_header);
+ const u8 *end = buf + hdr_length;
+ char msgbuf[32];
+ int status = 0;
+ u32 len, msg_length;
+
+ if (le32_to_cpu(hdr->service_type) != RPM_SERVICE_TYPE_REQUEST ||
+ hdr_length < sizeof(struct qcom_rpm_message)) {
+ dev_err(&qsdev->dev, "invalid request\n");
+ return 0;
+ }
+
+ while (buf < end) {
+ msg = (struct qcom_rpm_message *)buf;
+ msg_length = le32_to_cpu(msg->length);
+ switch (le32_to_cpu(msg->msg_type)) {
+ case RPM_MSG_TYPE_MSG_ID:
+ break;
+ case RPM_MSG_TYPE_ERR:
+ len = min_t(u32, ALIGN(msg_length, 4), sizeof(msgbuf));
+ memcpy_fromio(msgbuf, msg->message, len);
+ msgbuf[len - 1] = 0;
+
+ if (!strcmp(msgbuf, "resource does not exist"))
+ status = -ENXIO;
+ else
+ status = -EINVAL;
+ break;
+ }
+
+ buf = PTR_ALIGN(buf + 2 * sizeof(u32) + msg_length, 4);
+ }
+
+ rpm->ack_status = status;
+ complete(&rpm->ack);
+ return 0;
+}
+
+static int qcom_smd_rpm_probe(struct qcom_smd_device *sdev)
+{
+ struct qcom_smd_rpm *rpm;
+
+ rpm = devm_kzalloc(&sdev->dev, sizeof(*rpm), GFP_KERNEL);
+ if (!rpm)
+ return -ENOMEM;
+
+ mutex_init(&rpm->lock);
+ init_completion(&rpm->ack);
+
+ rpm->rpm_channel = sdev->channel;
+
+ dev_set_drvdata(&sdev->dev, rpm);
+
+ return of_platform_populate(sdev->dev.of_node, NULL, NULL, &sdev->dev);
+}
+
+static void qcom_smd_rpm_remove(struct qcom_smd_device *sdev)
+{
+ of_platform_depopulate(&sdev->dev);
+}
+
+static const struct of_device_id qcom_smd_rpm_of_match[] = {
+ { .compatible = "qcom,rpm-msm8974" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, qcom_smd_rpm_of_match);
+
+static struct qcom_smd_driver qcom_smd_rpm_driver = {
+ .probe = qcom_smd_rpm_probe,
+ .remove = qcom_smd_rpm_remove,
+ .callback = qcom_smd_rpm_callback,
+ .driver = {
+ .name = "qcom_smd_rpm",
+ .owner = THIS_MODULE,
+ .of_match_table = qcom_smd_rpm_of_match,
+ },
+};
+
+static int __init qcom_smd_rpm_init(void)
+{
+ return qcom_smd_driver_register(&qcom_smd_rpm_driver);
+}
+arch_initcall(qcom_smd_rpm_init);
+
+static void __exit qcom_smd_rpm_exit(void)
+{
+ qcom_smd_driver_unregister(&qcom_smd_rpm_driver);
+}
+module_exit(qcom_smd_rpm_exit);
+
+MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
+MODULE_DESCRIPTION("Qualcomm SMD backed RPM driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff