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 time64_t date_and_time; 185 u32 packet; 186 int ret = rpi_firmware_property(fw, 187 RPI_FIRMWARE_GET_FIRMWARE_REVISION, 188 &packet, sizeof(packet)); 189 190 if (ret) 191 return; 192 193 /* This is not compatible with y2038 */ 194 date_and_time = packet; 195 dev_info(fw->cl.dev, "Attached to firmware from %ptT\n", &date_and_time); 196 } 197 198 static void 199 rpi_register_hwmon_driver(struct device *dev, struct rpi_firmware *fw) 200 { 201 u32 packet; 202 int ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_THROTTLED, 203 &packet, sizeof(packet)); 204 205 if (ret) 206 return; 207 208 rpi_hwmon = platform_device_register_data(dev, "raspberrypi-hwmon", 209 -1, NULL, 0); 210 } 211 212 static void rpi_register_clk_driver(struct device *dev) 213 { 214 struct device_node *firmware; 215 216 /* 217 * Earlier DTs don't have a node for the firmware clocks but 218 * rely on us creating a platform device by hand. If we do 219 * have a node for the firmware clocks, just bail out here. 220 */ 221 firmware = of_get_compatible_child(dev->of_node, 222 "raspberrypi,firmware-clocks"); 223 if (firmware) { 224 of_node_put(firmware); 225 return; 226 } 227 228 rpi_clk = platform_device_register_data(dev, "raspberrypi-clk", 229 -1, NULL, 0); 230 } 231 232 static int rpi_firmware_probe(struct platform_device *pdev) 233 { 234 struct device *dev = &pdev->dev; 235 struct rpi_firmware *fw; 236 237 fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL); 238 if (!fw) 239 return -ENOMEM; 240 241 fw->cl.dev = dev; 242 fw->cl.rx_callback = response_callback; 243 fw->cl.tx_block = true; 244 245 fw->chan = mbox_request_channel(&fw->cl, 0); 246 if (IS_ERR(fw->chan)) { 247 int ret = PTR_ERR(fw->chan); 248 if (ret != -EPROBE_DEFER) 249 dev_err(dev, "Failed to get mbox channel: %d\n", ret); 250 return ret; 251 } 252 253 init_completion(&fw->c); 254 255 platform_set_drvdata(pdev, fw); 256 257 rpi_firmware_print_firmware_revision(fw); 258 rpi_register_hwmon_driver(dev, fw); 259 rpi_register_clk_driver(dev); 260 261 return 0; 262 } 263 264 static void rpi_firmware_shutdown(struct platform_device *pdev) 265 { 266 struct rpi_firmware *fw = platform_get_drvdata(pdev); 267 268 if (!fw) 269 return; 270 271 rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_REBOOT, NULL, 0); 272 } 273 274 static int rpi_firmware_remove(struct platform_device *pdev) 275 { 276 struct rpi_firmware *fw = platform_get_drvdata(pdev); 277 278 platform_device_unregister(rpi_hwmon); 279 rpi_hwmon = NULL; 280 platform_device_unregister(rpi_clk); 281 rpi_clk = NULL; 282 mbox_free_channel(fw->chan); 283 284 return 0; 285 } 286 287 /** 288 * rpi_firmware_get - Get pointer to rpi_firmware structure. 289 * @firmware_node: Pointer to the firmware Device Tree node. 290 * 291 * Returns NULL is the firmware device is not ready. 292 */ 293 struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node) 294 { 295 struct platform_device *pdev = of_find_device_by_node(firmware_node); 296 297 if (!pdev) 298 return NULL; 299 300 return platform_get_drvdata(pdev); 301 } 302 EXPORT_SYMBOL_GPL(rpi_firmware_get); 303 304 /* 305 * The Raspberry Pi 4 gets its USB functionality from VL805, a PCIe chip that 306 * implements xHCI. After a PCI reset, VL805's firmware may either be loaded 307 * directly from an EEPROM or, if not present, by the SoC's co-processor, 308 * VideoCore. RPi4's VideoCore OS contains both the non public firmware load 309 * logic and the VL805 firmware blob. This function triggers the aforementioned 310 * process. 311 */ 312 int rpi_firmware_init_vl805(struct pci_dev *pdev) 313 { 314 struct device_node *fw_np; 315 struct rpi_firmware *fw; 316 u32 dev_addr, version; 317 int ret; 318 319 fw_np = of_find_compatible_node(NULL, NULL, 320 "raspberrypi,bcm2835-firmware"); 321 if (!fw_np) 322 return 0; 323 324 fw = rpi_firmware_get(fw_np); 325 of_node_put(fw_np); 326 if (!fw) 327 return -ENODEV; 328 329 /* 330 * Make sure we don't trigger a firmware load unnecessarily. 331 * 332 * If something went wrong with PCI, this whole exercise would be 333 * futile as VideoCore expects from us a configured PCI bus. Just take 334 * the faulty version (likely ~0) and let xHCI's registration fail 335 * further down the line. 336 */ 337 pci_read_config_dword(pdev, VL805_PCI_CONFIG_VERSION_OFFSET, &version); 338 if (version) 339 goto exit; 340 341 dev_addr = pdev->bus->number << 20 | PCI_SLOT(pdev->devfn) << 15 | 342 PCI_FUNC(pdev->devfn) << 12; 343 344 ret = rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_XHCI_RESET, 345 &dev_addr, sizeof(dev_addr)); 346 if (ret) 347 return ret; 348 349 /* Wait for vl805 to startup */ 350 usleep_range(200, 1000); 351 352 pci_read_config_dword(pdev, VL805_PCI_CONFIG_VERSION_OFFSET, 353 &version); 354 exit: 355 pci_info(pdev, "VL805 firmware version %08x\n", version); 356 357 return 0; 358 } 359 EXPORT_SYMBOL_GPL(rpi_firmware_init_vl805); 360 361 static const struct of_device_id rpi_firmware_of_match[] = { 362 { .compatible = "raspberrypi,bcm2835-firmware", }, 363 {}, 364 }; 365 MODULE_DEVICE_TABLE(of, rpi_firmware_of_match); 366 367 static struct platform_driver rpi_firmware_driver = { 368 .driver = { 369 .name = "raspberrypi-firmware", 370 .of_match_table = rpi_firmware_of_match, 371 }, 372 .probe = rpi_firmware_probe, 373 .shutdown = rpi_firmware_shutdown, 374 .remove = rpi_firmware_remove, 375 }; 376 module_platform_driver(rpi_firmware_driver); 377 378 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>"); 379 MODULE_DESCRIPTION("Raspberry Pi firmware driver"); 380 MODULE_LICENSE("GPL v2"); 381