/* * Defines interfaces for interacting wtih the Raspberry Pi firmware's * property channel. * * Copyright © 2015 Broadcom * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #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 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) { wait_for_completion(&fw->c); ret = 0; } 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) return -EINVAL; buf = dma_alloc_coherent(fw->cl.dev, PAGE_ALIGN(size), &bus_addr, GFP_ATOMIC); if (!buf) return -ENOMEM; /* The firmware will error out without parsing in this case. */ WARN_ON(size >= 1024 * 1024); buf[0] = size; buf[1] = RPI_FIRMWARE_STATUS_REQUEST; memcpy(&buf[2], data, tag_size); buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END; wmb(); ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr); rmb(); memcpy(data, &buf[2], tag_size); if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) { /* * The tag name here might not be the one causing the * error, if there were multiple tags in the request. * But single-tag is the most common, so go with it. */ dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n", buf[2], buf[1]); ret = -EINVAL; } dma_free_coherent(fw->cl.dev, PAGE_ALIGN(size), buf, bus_addr); return ret; } EXPORT_SYMBOL_GPL(rpi_firmware_property_list); /** * rpi_firmware_property - Submit single firmware property * @fw: Pointer to firmware structure from rpi_firmware_get(). * @tag: One of enum_mbox_property_tag. * @tag_data: Tag data buffer. * @buf_size: Buffer size. * * Submits a single tag to the VPU firmware through the mailbox * property interface. * * This is a convenience wrapper around * rpi_firmware_property_list() to avoid some of the * boilerplate in property calls. */ int rpi_firmware_property(struct rpi_firmware *fw, u32 tag, void *tag_data, size_t buf_size) { /* Single tags are very small (generally 8 bytes), so the * stack should be safe. */ u8 data[buf_size + sizeof(struct rpi_firmware_property_tag_header)]; struct rpi_firmware_property_tag_header *header = (struct rpi_firmware_property_tag_header *)data; int ret; header->tag = tag; header->buf_size = buf_size; header->req_resp_size = 0; memcpy(data + sizeof(struct rpi_firmware_property_tag_header), tag_data, buf_size); ret = rpi_firmware_property_list(fw, &data, sizeof(data)); memcpy(tag_data, data + sizeof(struct rpi_firmware_property_tag_header), buf_size); return ret; } EXPORT_SYMBOL_GPL(rpi_firmware_property); static void rpi_firmware_print_firmware_revision(struct rpi_firmware *fw) { u32 packet; int ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_FIRMWARE_REVISION, &packet, sizeof(packet)); if (ret == 0) { struct tm tm; time_to_tm(packet, 0, &tm); dev_info(fw->cl.dev, "Attached to firmware from %04ld-%02d-%02d %02d:%02d\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min); } } static int rpi_firmware_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct rpi_firmware *fw; fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL); if (!fw) return -ENOMEM; fw->cl.dev = dev; fw->cl.rx_callback = response_callback; fw->cl.tx_block = true; fw->chan = mbox_request_channel(&fw->cl, 0); if (IS_ERR(fw->chan)) { int ret = PTR_ERR(fw->chan); if (ret != -EPROBE_DEFER) dev_err(dev, "Failed to get mbox channel: %d\n", ret); return ret; } init_completion(&fw->c); platform_set_drvdata(pdev, fw); rpi_firmware_print_firmware_revision(fw); return 0; } static int rpi_firmware_remove(struct platform_device *pdev) { struct rpi_firmware *fw = platform_get_drvdata(pdev); mbox_free_channel(fw->chan); return 0; } /** * rpi_firmware_get - Get pointer to rpi_firmware structure. * @firmware_node: Pointer to the firmware Device Tree node. * * Returns NULL is the firmware device is not ready. */ struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node) { struct platform_device *pdev = of_find_device_by_node(firmware_node); if (!pdev) return NULL; return platform_get_drvdata(pdev); } EXPORT_SYMBOL_GPL(rpi_firmware_get); static const struct of_device_id rpi_firmware_of_match[] = { { .compatible = "raspberrypi,bcm2835-firmware", }, {}, }; MODULE_DEVICE_TABLE(of, rpi_firmware_of_match); static struct platform_driver rpi_firmware_driver = { .driver = { .name = "raspberrypi-firmware", .of_match_table = rpi_firmware_of_match, }, .probe = rpi_firmware_probe, .remove = rpi_firmware_remove, }; module_platform_driver(rpi_firmware_driver); MODULE_AUTHOR("Eric Anholt "); MODULE_DESCRIPTION("Raspberry Pi firmware driver"); MODULE_LICENSE("GPL v2");