| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Defines interfaces for interacting wtih the Raspberry Pi firmware's |
| 4 | * property channel. |
| 5 | * |
| 6 | * Copyright © 2015 Broadcom |
| 7 | */ |
| 8 | |
| 9 | #include <linux/dma-mapping.h> |
| 10 | #include <linux/mailbox_client.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/of_platform.h> |
| 13 | #include <linux/platform_device.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/pci.h> |
| 16 | #include <linux/delay.h> |
| 17 | #include <soc/bcm2835/raspberrypi-firmware.h> |
| 18 | |
| 19 | #define MBOX_MSG(chan, data28) (((data28) & ~0xf) | ((chan) & 0xf)) |
| 20 | #define MBOX_CHAN(msg) ((msg) & 0xf) |
| 21 | #define MBOX_DATA28(msg) ((msg) & ~0xf) |
| 22 | #define MBOX_CHAN_PROPERTY 8 |
| 23 | |
| 24 | #define VL805_PCI_CONFIG_VERSION_OFFSET 0x50 |
| 25 | |
| 26 | static struct platform_device *rpi_hwmon; |
| 27 | static struct platform_device *rpi_clk; |
| 28 | |
| 29 | struct rpi_firmware { |
| 30 | struct mbox_client cl; |
| 31 | struct mbox_chan *chan; /* The property channel. */ |
| 32 | struct completion c; |
| 33 | u32 enabled; |
| 34 | }; |
| 35 | |
| 36 | static DEFINE_MUTEX(transaction_lock); |
| 37 | |
| 38 | static void response_callback(struct mbox_client *cl, void *msg) |
| 39 | { |
| 40 | struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl); |
| 41 | complete(&fw->c); |
| 42 | } |
| 43 | |
| 44 | /* |
| 45 | * Sends a request to the firmware through the BCM2835 mailbox driver, |
| 46 | * and synchronously waits for the reply. |
| 47 | */ |
| 48 | static int |
| 49 | rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data) |
| 50 | { |
| 51 | u32 message = MBOX_MSG(chan, data); |
| 52 | int ret; |
| 53 | |
| 54 | WARN_ON(data & 0xf); |
| 55 | |
| 56 | mutex_lock(&transaction_lock); |
| 57 | reinit_completion(&fw->c); |
| 58 | ret = mbox_send_message(fw->chan, &message); |
| 59 | if (ret >= 0) { |
| 60 | if (wait_for_completion_timeout(&fw->c, HZ)) { |
| 61 | ret = 0; |
| 62 | } else { |
| 63 | ret = -ETIMEDOUT; |
| 64 | WARN_ONCE(1, "Firmware transaction timeout"); |
| 65 | } |
| 66 | } else { |
| 67 | dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret); |
| 68 | } |
| 69 | mutex_unlock(&transaction_lock); |
| 70 | |
| 71 | return ret; |
| 72 | } |
| 73 | |
| 74 | /** |
| 75 | * rpi_firmware_property_list - Submit firmware property list |
| 76 | * @fw: Pointer to firmware structure from rpi_firmware_get(). |
| 77 | * @data: Buffer holding tags. |
| 78 | * @tag_size: Size of tags buffer. |
| 79 | * |
| 80 | * Submits a set of concatenated tags to the VPU firmware through the |
| 81 | * mailbox property interface. |
| 82 | * |
| 83 | * The buffer header and the ending tag are added by this function and |
| 84 | * don't need to be supplied, just the actual tags for your operation. |
| 85 | * See struct rpi_firmware_property_tag_header for the per-tag |
| 86 | * structure. |
| 87 | */ |
| 88 | int rpi_firmware_property_list(struct rpi_firmware *fw, |
| 89 | void *data, size_t tag_size) |
| 90 | { |
| 91 | size_t size = tag_size + 12; |
| 92 | u32 *buf; |
| 93 | dma_addr_t bus_addr; |
| 94 | int ret; |
| 95 | |
| 96 | /* Packets are processed a dword at a time. */ |
| 97 | if (size & 3) |
| 98 | return -EINVAL; |
| 99 | |
| 100 | buf = dma_alloc_coherent(fw->cl.dev, PAGE_ALIGN(size), &bus_addr, |
| 101 | GFP_ATOMIC); |
| 102 | if (!buf) |
| 103 | return -ENOMEM; |
| 104 | |
| 105 | /* The firmware will error out without parsing in this case. */ |
| 106 | WARN_ON(size >= 1024 * 1024); |
| 107 | |
| 108 | buf[0] = size; |
| 109 | buf[1] = RPI_FIRMWARE_STATUS_REQUEST; |
| 110 | memcpy(&buf[2], data, tag_size); |
| 111 | buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END; |
| 112 | wmb(); |
| 113 | |
| 114 | ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr); |
| 115 | |
| 116 | rmb(); |
| 117 | memcpy(data, &buf[2], tag_size); |
| 118 | if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) { |
| 119 | /* |
| 120 | * The tag name here might not be the one causing the |
| 121 | * error, if there were multiple tags in the request. |
| 122 | * But single-tag is the most common, so go with it. |
| 123 | */ |
| 124 | dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n", |
| 125 | buf[2], buf[1]); |
| 126 | ret = -EINVAL; |
| 127 | } |
| 128 | |
| 129 | dma_free_coherent(fw->cl.dev, PAGE_ALIGN(size), buf, bus_addr); |
| 130 | |
| 131 | return ret; |
| 132 | } |
| 133 | EXPORT_SYMBOL_GPL(rpi_firmware_property_list); |
| 134 | |
| 135 | /** |
| 136 | * rpi_firmware_property - Submit single firmware property |
| 137 | * @fw: Pointer to firmware structure from rpi_firmware_get(). |
| 138 | * @tag: One of enum_mbox_property_tag. |
| 139 | * @tag_data: Tag data buffer. |
| 140 | * @buf_size: Buffer size. |
| 141 | * |
| 142 | * Submits a single tag to the VPU firmware through the mailbox |
| 143 | * property interface. |
| 144 | * |
| 145 | * This is a convenience wrapper around |
| 146 | * rpi_firmware_property_list() to avoid some of the |
| 147 | * boilerplate in property calls. |
| 148 | */ |
| 149 | int rpi_firmware_property(struct rpi_firmware *fw, |
| 150 | u32 tag, void *tag_data, size_t buf_size) |
| 151 | { |
| 152 | struct rpi_firmware_property_tag_header *header; |
| 153 | int ret; |
| 154 | |
| 155 | /* Some mailboxes can use over 1k bytes. Rather than checking |
| 156 | * size and using stack or kmalloc depending on requirements, |
| 157 | * just use kmalloc. Mailboxes don't get called enough to worry |
| 158 | * too much about the time taken in the allocation. |
| 159 | */ |
| 160 | void *data = kmalloc(sizeof(*header) + buf_size, GFP_KERNEL); |
| 161 | |
| 162 | if (!data) |
| 163 | return -ENOMEM; |
| 164 | |
| 165 | header = data; |
| 166 | header->tag = tag; |
| 167 | header->buf_size = buf_size; |
| 168 | header->req_resp_size = 0; |
| 169 | memcpy(data + sizeof(*header), tag_data, buf_size); |
| 170 | |
| 171 | ret = rpi_firmware_property_list(fw, data, buf_size + sizeof(*header)); |
| 172 | |
| 173 | memcpy(tag_data, data + sizeof(*header), buf_size); |
| 174 | |
| 175 | kfree(data); |
| 176 | |
| 177 | return ret; |
| 178 | } |
| 179 | EXPORT_SYMBOL_GPL(rpi_firmware_property); |
| 180 | |
| 181 | static void |
| 182 | rpi_firmware_print_firmware_revision(struct rpi_firmware *fw) |
| 183 | { |
| 184 | u32 packet; |
| 185 | int ret = rpi_firmware_property(fw, |
| 186 | RPI_FIRMWARE_GET_FIRMWARE_REVISION, |
| 187 | &packet, sizeof(packet)); |
| 188 | |
| 189 | if (ret) |
| 190 | return; |
| 191 | |
| 192 | dev_info(fw->cl.dev, "Attached to firmware from %ptT\n", &packet); |
| 193 | } |
| 194 | |
| 195 | static void |
| 196 | rpi_register_hwmon_driver(struct device *dev, struct rpi_firmware *fw) |
| 197 | { |
| 198 | u32 packet; |
| 199 | int ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_THROTTLED, |
| 200 | &packet, sizeof(packet)); |
| 201 | |
| 202 | if (ret) |
| 203 | return; |
| 204 | |
| 205 | rpi_hwmon = platform_device_register_data(dev, "raspberrypi-hwmon", |
| 206 | -1, NULL, 0); |
| 207 | } |
| 208 | |
| 209 | static void rpi_register_clk_driver(struct device *dev) |
| 210 | { |
| 211 | rpi_clk = platform_device_register_data(dev, "raspberrypi-clk", |
| 212 | -1, NULL, 0); |
| 213 | } |
| 214 | |
| 215 | static int rpi_firmware_probe(struct platform_device *pdev) |
| 216 | { |
| 217 | struct device *dev = &pdev->dev; |
| 218 | struct rpi_firmware *fw; |
| 219 | |
| 220 | fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL); |
| 221 | if (!fw) |
| 222 | return -ENOMEM; |
| 223 | |
| 224 | fw->cl.dev = dev; |
| 225 | fw->cl.rx_callback = response_callback; |
| 226 | fw->cl.tx_block = true; |
| 227 | |
| 228 | fw->chan = mbox_request_channel(&fw->cl, 0); |
| 229 | if (IS_ERR(fw->chan)) { |
| 230 | int ret = PTR_ERR(fw->chan); |
| 231 | if (ret != -EPROBE_DEFER) |
| 232 | dev_err(dev, "Failed to get mbox channel: %d\n", ret); |
| 233 | return ret; |
| 234 | } |
| 235 | |
| 236 | init_completion(&fw->c); |
| 237 | |
| 238 | platform_set_drvdata(pdev, fw); |
| 239 | |
| 240 | rpi_firmware_print_firmware_revision(fw); |
| 241 | rpi_register_hwmon_driver(dev, fw); |
| 242 | rpi_register_clk_driver(dev); |
| 243 | |
| 244 | return 0; |
| 245 | } |
| 246 | |
| 247 | static void rpi_firmware_shutdown(struct platform_device *pdev) |
| 248 | { |
| 249 | struct rpi_firmware *fw = platform_get_drvdata(pdev); |
| 250 | |
| 251 | if (!fw) |
| 252 | return; |
| 253 | |
| 254 | rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_REBOOT, NULL, 0); |
| 255 | } |
| 256 | |
| 257 | static int rpi_firmware_remove(struct platform_device *pdev) |
| 258 | { |
| 259 | struct rpi_firmware *fw = platform_get_drvdata(pdev); |
| 260 | |
| 261 | platform_device_unregister(rpi_hwmon); |
| 262 | rpi_hwmon = NULL; |
| 263 | platform_device_unregister(rpi_clk); |
| 264 | rpi_clk = NULL; |
| 265 | mbox_free_channel(fw->chan); |
| 266 | |
| 267 | return 0; |
| 268 | } |
| 269 | |
| 270 | /** |
| 271 | * rpi_firmware_get - Get pointer to rpi_firmware structure. |
| 272 | * @firmware_node: Pointer to the firmware Device Tree node. |
| 273 | * |
| 274 | * Returns NULL is the firmware device is not ready. |
| 275 | */ |
| 276 | struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node) |
| 277 | { |
| 278 | struct platform_device *pdev = of_find_device_by_node(firmware_node); |
| 279 | |
| 280 | if (!pdev) |
| 281 | return NULL; |
| 282 | |
| 283 | return platform_get_drvdata(pdev); |
| 284 | } |
| 285 | EXPORT_SYMBOL_GPL(rpi_firmware_get); |
| 286 | |
| 287 | /* |
| 288 | * The Raspberry Pi 4 gets its USB functionality from VL805, a PCIe chip that |
| 289 | * implements xHCI. After a PCI reset, VL805's firmware may either be loaded |
| 290 | * directly from an EEPROM or, if not present, by the SoC's co-processor, |
| 291 | * VideoCore. RPi4's VideoCore OS contains both the non public firmware load |
| 292 | * logic and the VL805 firmware blob. This function triggers the aforementioned |
| 293 | * process. |
| 294 | */ |
| 295 | int rpi_firmware_init_vl805(struct pci_dev *pdev) |
| 296 | { |
| 297 | struct device_node *fw_np; |
| 298 | struct rpi_firmware *fw; |
| 299 | u32 dev_addr, version; |
| 300 | int ret; |
| 301 | |
| 302 | fw_np = of_find_compatible_node(NULL, NULL, |
| 303 | "raspberrypi,bcm2835-firmware"); |
| 304 | if (!fw_np) |
| 305 | return 0; |
| 306 | |
| 307 | fw = rpi_firmware_get(fw_np); |
| 308 | of_node_put(fw_np); |
| 309 | if (!fw) |
| 310 | return -ENODEV; |
| 311 | |
| 312 | /* |
| 313 | * Make sure we don't trigger a firmware load unnecessarily. |
| 314 | * |
| 315 | * If something went wrong with PCI, this whole exercise would be |
| 316 | * futile as VideoCore expects from us a configured PCI bus. Just take |
| 317 | * the faulty version (likely ~0) and let xHCI's registration fail |
| 318 | * further down the line. |
| 319 | */ |
| 320 | pci_read_config_dword(pdev, VL805_PCI_CONFIG_VERSION_OFFSET, &version); |
| 321 | if (version) |
| 322 | goto exit; |
| 323 | |
| 324 | dev_addr = pdev->bus->number << 20 | PCI_SLOT(pdev->devfn) << 15 | |
| 325 | PCI_FUNC(pdev->devfn) << 12; |
| 326 | |
| 327 | ret = rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_XHCI_RESET, |
| 328 | &dev_addr, sizeof(dev_addr)); |
| 329 | if (ret) |
| 330 | return ret; |
| 331 | |
| 332 | /* Wait for vl805 to startup */ |
| 333 | usleep_range(200, 1000); |
| 334 | |
| 335 | pci_read_config_dword(pdev, VL805_PCI_CONFIG_VERSION_OFFSET, |
| 336 | &version); |
| 337 | exit: |
| 338 | pci_info(pdev, "VL805 firmware version %08x\n", version); |
| 339 | |
| 340 | return 0; |
| 341 | } |
| 342 | EXPORT_SYMBOL_GPL(rpi_firmware_init_vl805); |
| 343 | |
| 344 | static const struct of_device_id rpi_firmware_of_match[] = { |
| 345 | { .compatible = "raspberrypi,bcm2835-firmware", }, |
| 346 | {}, |
| 347 | }; |
| 348 | MODULE_DEVICE_TABLE(of, rpi_firmware_of_match); |
| 349 | |
| 350 | static struct platform_driver rpi_firmware_driver = { |
| 351 | .driver = { |
| 352 | .name = "raspberrypi-firmware", |
| 353 | .of_match_table = rpi_firmware_of_match, |
| 354 | }, |
| 355 | .probe = rpi_firmware_probe, |
| 356 | .shutdown = rpi_firmware_shutdown, |
| 357 | .remove = rpi_firmware_remove, |
| 358 | }; |
| 359 | module_platform_driver(rpi_firmware_driver); |
| 360 | |
| 361 | MODULE_AUTHOR("Eric Anholt <eric@anholt.net>"); |
| 362 | MODULE_DESCRIPTION("Raspberry Pi firmware driver"); |
| 363 | MODULE_LICENSE("GPL v2"); |