261 lines
6.6 KiB
C
261 lines
6.6 KiB
C
/*
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* Defines interfaces for interacting wtih the Raspberry Pi firmware's
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* property channel.
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*
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* Copyright © 2015 Broadcom
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/dma-mapping.h>
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#include <linux/mailbox_client.h>
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#include <linux/module.h>
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#include <linux/of_platform.h>
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#include <linux/platform_device.h>
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#include <soc/bcm2835/raspberrypi-firmware.h>
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#define MBOX_MSG(chan, data28) (((data28) & ~0xf) | ((chan) & 0xf))
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#define MBOX_CHAN(msg) ((msg) & 0xf)
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#define MBOX_DATA28(msg) ((msg) & ~0xf)
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#define MBOX_CHAN_PROPERTY 8
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struct rpi_firmware {
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struct mbox_client cl;
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struct mbox_chan *chan; /* The property channel. */
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struct completion c;
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u32 enabled;
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};
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static DEFINE_MUTEX(transaction_lock);
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static void response_callback(struct mbox_client *cl, void *msg)
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{
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struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl);
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complete(&fw->c);
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}
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/*
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* Sends a request to the firmware through the BCM2835 mailbox driver,
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* and synchronously waits for the reply.
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*/
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static int
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rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data)
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{
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u32 message = MBOX_MSG(chan, data);
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int ret;
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WARN_ON(data & 0xf);
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mutex_lock(&transaction_lock);
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reinit_completion(&fw->c);
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ret = mbox_send_message(fw->chan, &message);
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if (ret >= 0) {
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wait_for_completion(&fw->c);
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ret = 0;
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} else {
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dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret);
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}
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mutex_unlock(&transaction_lock);
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return ret;
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}
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/**
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* rpi_firmware_property_list - Submit firmware property list
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* @fw: Pointer to firmware structure from rpi_firmware_get().
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* @data: Buffer holding tags.
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* @tag_size: Size of tags buffer.
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*
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* Submits a set of concatenated tags to the VPU firmware through the
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* mailbox property interface.
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*
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* The buffer header and the ending tag are added by this function and
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* don't need to be supplied, just the actual tags for your operation.
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* See struct rpi_firmware_property_tag_header for the per-tag
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* structure.
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*/
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int rpi_firmware_property_list(struct rpi_firmware *fw,
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void *data, size_t tag_size)
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{
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size_t size = tag_size + 12;
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u32 *buf;
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dma_addr_t bus_addr;
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int ret;
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/* Packets are processed a dword at a time. */
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if (size & 3)
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return -EINVAL;
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buf = dma_alloc_coherent(fw->cl.dev, PAGE_ALIGN(size), &bus_addr,
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GFP_ATOMIC);
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if (!buf)
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return -ENOMEM;
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/* The firmware will error out without parsing in this case. */
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WARN_ON(size >= 1024 * 1024);
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buf[0] = size;
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buf[1] = RPI_FIRMWARE_STATUS_REQUEST;
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memcpy(&buf[2], data, tag_size);
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buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END;
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wmb();
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ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr);
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rmb();
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memcpy(data, &buf[2], tag_size);
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if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) {
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/*
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* The tag name here might not be the one causing the
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* error, if there were multiple tags in the request.
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* But single-tag is the most common, so go with it.
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*/
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dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n",
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buf[2], buf[1]);
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ret = -EINVAL;
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}
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dma_free_coherent(fw->cl.dev, PAGE_ALIGN(size), buf, bus_addr);
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return ret;
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}
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EXPORT_SYMBOL_GPL(rpi_firmware_property_list);
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/**
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* rpi_firmware_property - Submit single firmware property
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* @fw: Pointer to firmware structure from rpi_firmware_get().
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* @tag: One of enum_mbox_property_tag.
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* @tag_data: Tag data buffer.
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* @buf_size: Buffer size.
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*
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* Submits a single tag to the VPU firmware through the mailbox
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* property interface.
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*
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* This is a convenience wrapper around
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* rpi_firmware_property_list() to avoid some of the
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* boilerplate in property calls.
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*/
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int rpi_firmware_property(struct rpi_firmware *fw,
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u32 tag, void *tag_data, size_t buf_size)
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{
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/* Single tags are very small (generally 8 bytes), so the
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* stack should be safe.
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*/
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u8 data[buf_size + sizeof(struct rpi_firmware_property_tag_header)];
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struct rpi_firmware_property_tag_header *header =
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(struct rpi_firmware_property_tag_header *)data;
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int ret;
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header->tag = tag;
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header->buf_size = buf_size;
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header->req_resp_size = 0;
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memcpy(data + sizeof(struct rpi_firmware_property_tag_header),
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tag_data, buf_size);
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ret = rpi_firmware_property_list(fw, &data, sizeof(data));
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memcpy(tag_data,
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data + sizeof(struct rpi_firmware_property_tag_header),
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buf_size);
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return ret;
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}
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EXPORT_SYMBOL_GPL(rpi_firmware_property);
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static void
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rpi_firmware_print_firmware_revision(struct rpi_firmware *fw)
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{
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u32 packet;
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int ret = rpi_firmware_property(fw,
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RPI_FIRMWARE_GET_FIRMWARE_REVISION,
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&packet, sizeof(packet));
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if (ret == 0) {
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struct tm tm;
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time_to_tm(packet, 0, &tm);
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dev_info(fw->cl.dev,
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"Attached to firmware from %04ld-%02d-%02d %02d:%02d\n",
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tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
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tm.tm_hour, tm.tm_min);
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}
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}
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static int rpi_firmware_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct rpi_firmware *fw;
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fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL);
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if (!fw)
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return -ENOMEM;
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fw->cl.dev = dev;
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fw->cl.rx_callback = response_callback;
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fw->cl.tx_block = true;
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fw->chan = mbox_request_channel(&fw->cl, 0);
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if (IS_ERR(fw->chan)) {
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int ret = PTR_ERR(fw->chan);
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if (ret != -EPROBE_DEFER)
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dev_err(dev, "Failed to get mbox channel: %d\n", ret);
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return ret;
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}
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init_completion(&fw->c);
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platform_set_drvdata(pdev, fw);
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rpi_firmware_print_firmware_revision(fw);
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return 0;
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}
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static int rpi_firmware_remove(struct platform_device *pdev)
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{
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struct rpi_firmware *fw = platform_get_drvdata(pdev);
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mbox_free_channel(fw->chan);
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return 0;
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}
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/**
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* rpi_firmware_get - Get pointer to rpi_firmware structure.
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* @firmware_node: Pointer to the firmware Device Tree node.
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*
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* Returns NULL is the firmware device is not ready.
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*/
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struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node)
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{
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struct platform_device *pdev = of_find_device_by_node(firmware_node);
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if (!pdev)
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return NULL;
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return platform_get_drvdata(pdev);
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}
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EXPORT_SYMBOL_GPL(rpi_firmware_get);
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static const struct of_device_id rpi_firmware_of_match[] = {
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{ .compatible = "raspberrypi,bcm2835-firmware", },
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{},
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};
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MODULE_DEVICE_TABLE(of, rpi_firmware_of_match);
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static struct platform_driver rpi_firmware_driver = {
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.driver = {
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.name = "raspberrypi-firmware",
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.of_match_table = rpi_firmware_of_match,
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},
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.probe = rpi_firmware_probe,
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.remove = rpi_firmware_remove,
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};
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module_platform_driver(rpi_firmware_driver);
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MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
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MODULE_DESCRIPTION("Raspberry Pi firmware driver");
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MODULE_LICENSE("GPL v2");
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