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