linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Defines interfaces for interacting wtih the Raspberry Pi firmware's

 * property channel.

 *

 * Copyright © 2015 Broadcom

 */

​

#include <linux/dma-mapping.h>

#include <linux/mailbox_client.h>

#include <linux/module.h>

#include <linux/of_platform.h>

#include <linux/platform_device.h>

#include <linux/slab.h>

#include <soc/bcm2835/raspberrypi-firmware.h>

​

#define MBOX_MSG(chan, data28)      (((data28) & ~0xf) | ((chan) & 0xf))

#define MBOX_CHAN(msg)          ((msg) & 0xf)

#define MBOX_DATA28(msg)        ((msg) & ~0xf)

#define MBOX_CHAN_PROPERTY      8

​

static struct platform_device *rpi_hwmon;

​

struct rpi_firmware {

    struct mbox_client cl;

    struct mbox_chan *chan; /* The property channel. */

    struct completion c;

    u32 enabled;

};

​

static DEFINE_MUTEX(transaction_lock);

​

static void response_callback(struct mbox_client *cl, void *msg)

{

    struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl);

    complete(&fw->c);

}

​

/*

 * Sends a request to the firmware through the BCM2835 mailbox driver,

 * and synchronously waits for the reply.

 */

static int

rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data)

{

    u32 message = MBOX_MSG(chan, data);

    int ret;

​

    WARN_ON(data & 0xf);

​

    mutex_lock(&transaction_lock);

    reinit_completion(&fw->c);

    ret = mbox_send_message(fw->chan, &message);

    if (ret >= 0) {

        if (wait_for_completion_timeout(&fw->c, HZ)) {

            ret = 0;

        } else {

            ret = -ETIMEDOUT;

            WARN_ONCE(1, "Firmware transaction timeout");

        }

    } else {

        dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret);

    }

    mutex_unlock(&transaction_lock);

​

    return ret;

}

​

/**

 * rpi_firmware_property_list - Submit firmware property list

 * @fw:     Pointer to firmware structure from rpi_firmware_get().

 * @data:   Buffer holding tags.

 * @tag_size:   Size of tags buffer.

 *

 * Submits a set of concatenated tags to the VPU firmware through the

 * mailbox property interface.

 *

 * The buffer header and the ending tag are added by this function and

 * don't need to be supplied, just the actual tags for your operation.

 * See struct rpi_firmware_property_tag_header for the per-tag

 * structure.

 */

int rpi_firmware_property_list(struct rpi_firmware *fw,

                   void *data, size_t tag_size)

{

    size_t size = tag_size + 12;

    u32 *buf;

    dma_addr_t bus_addr;

    int ret;

​

    /* Packets are processed a dword at a time. */

    if (size & 3)