1 /* 2 * Defines interfaces for interacting wtih the Raspberry Pi firmware's 3 * property channel. 4 * 5 * Copyright © 2015 Broadcom 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 */ 11 12 #include <linux/dma-mapping.h> 13 #include <linux/mailbox_client.h> 14 #include <linux/module.h> 15 #include <linux/of_platform.h> 16 #include <linux/platform_device.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 struct rpi_firmware { 25 struct mbox_client cl; 26 struct mbox_chan *chan; /* The property channel. */ 27 struct completion c; 28 u32 enabled; 29 }; 30 31 static DEFINE_MUTEX(transaction_lock); 32 33 static void response_callback(struct mbox_client *cl, void *msg) 34 { 35 struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl); 36 complete(&fw->c); 37 } 38 39 /* 40 * Sends a request to the firmware through the BCM2835 mailbox driver, 41 * and synchronously waits for the reply. 42 */ 43 static int 44 rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data) 45 { 46 u32 message = MBOX_MSG(chan, data); 47 int ret; 48 49 WARN_ON(data & 0xf); 50 51 mutex_lock(&transaction_lock); 52 reinit_completion(&fw->c); 53 ret = mbox_send_message(fw->chan, &message); 54 if (ret >= 0) { 55 wait_for_completion(&fw->c); 56 ret = 0; 57 } else { 58 dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret); 59 } 60 mutex_unlock(&transaction_lock); 61 62 return ret; 63 } 64 65 /** 66 * rpi_firmware_property_list - Submit firmware property list 67 * @fw: Pointer to firmware structure from rpi_firmware_get(). 68 * @data: Buffer holding tags. 69 * @tag_size: Size of tags buffer. 70 * 71 * Submits a set of concatenated tags to the VPU firmware through the 72 * mailbox property interface. 73 * 74 * The buffer header and the ending tag are added by this function and 75 * don't need to be supplied, just the actual tags for your operation. 76 * See struct rpi_firmware_property_tag_header for the per-tag 77 * structure. 78 */ 79 int rpi_firmware_property_list(struct rpi_firmware *fw, 80 void *data, size_t tag_size) 81 { 82 size_t size = tag_size + 12; 83 u32 *buf; 84 dma_addr_t bus_addr; 85 int ret; 86 87 /* Packets are processed a dword at a time. */ 88 if (size & 3) 89 return -EINVAL; 90 91 buf = dma_alloc_coherent(fw->cl.dev, PAGE_ALIGN(size), &bus_addr, 92 GFP_ATOMIC); 93 if (!buf) 94 return -ENOMEM; 95 96 /* The firmware will error out without parsing in this case. */ 97 WARN_ON(size >= 1024 * 1024); 98 99 buf[0] = size; 100 buf[1] = RPI_FIRMWARE_STATUS_REQUEST; 101 memcpy(&buf[2], data, tag_size); 102 buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END; 103 wmb(); 104 105 ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr); 106 107 rmb(); 108 memcpy(data, &buf[2], tag_size); 109 if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) { 110 /* 111 * The tag name here might not be the one causing the 112 * error, if there were multiple tags in the request. 113 * But single-tag is the most common, so go with it. 114 */ 115 dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n", 116 buf[2], buf[1]); 117 ret = -EINVAL; 118 } 119 120 dma_free_coherent(fw->cl.dev, PAGE_ALIGN(size), buf, bus_addr); 121 122 return ret; 123 } 124 EXPORT_SYMBOL_GPL(rpi_firmware_property_list); 125 126 /** 127 * rpi_firmware_property - Submit single firmware property 128 * @fw: Pointer to firmware structure from rpi_firmware_get(). 129 * @tag: One of enum_mbox_property_tag. 130 * @tag_data: Tag data buffer. 131 * @buf_size: Buffer size. 132 * 133 * Submits a single tag to the VPU firmware through the mailbox 134 * property interface. 135 * 136 * This is a convenience wrapper around 137 * rpi_firmware_property_list() to avoid some of the 138 * boilerplate in property calls. 139 */ 140 int rpi_firmware_property(struct rpi_firmware *fw, 141 u32 tag, void *tag_data, size_t buf_size) 142 { 143 /* Single tags are very small (generally 8 bytes), so the 144 * stack should be safe. 145 */ 146 u8 data[buf_size + sizeof(struct rpi_firmware_property_tag_header)]; 147 struct rpi_firmware_property_tag_header *header = 148 (struct rpi_firmware_property_tag_header *)data; 149 int ret; 150 151 header->tag = tag; 152 header->buf_size = buf_size; 153 header->req_resp_size = 0; 154 memcpy(data + sizeof(struct rpi_firmware_property_tag_header), 155 tag_data, buf_size); 156 157 ret = rpi_firmware_property_list(fw, &data, sizeof(data)); 158 memcpy(tag_data, 159 data + sizeof(struct rpi_firmware_property_tag_header), 160 buf_size); 161 162 return ret; 163 } 164 EXPORT_SYMBOL_GPL(rpi_firmware_property); 165 166 static void 167 rpi_firmware_print_firmware_revision(struct rpi_firmware *fw) 168 { 169 u32 packet; 170 int ret = rpi_firmware_property(fw, 171 RPI_FIRMWARE_GET_FIRMWARE_REVISION, 172 &packet, sizeof(packet)); 173 174 if (ret == 0) { 175 struct tm tm; 176 177 time64_to_tm(packet, 0, &tm); 178 179 dev_info(fw->cl.dev, 180 "Attached to firmware from %04ld-%02d-%02d %02d:%02d\n", 181 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 182 tm.tm_hour, tm.tm_min); 183 } 184 } 185 186 static int rpi_firmware_probe(struct platform_device *pdev) 187 { 188 struct device *dev = &pdev->dev; 189 struct rpi_firmware *fw; 190 191 fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL); 192 if (!fw) 193 return -ENOMEM; 194 195 fw->cl.dev = dev; 196 fw->cl.rx_callback = response_callback; 197 fw->cl.tx_block = true; 198 199 fw->chan = mbox_request_channel(&fw->cl, 0); 200 if (IS_ERR(fw->chan)) { 201 int ret = PTR_ERR(fw->chan); 202 if (ret != -EPROBE_DEFER) 203 dev_err(dev, "Failed to get mbox channel: %d\n", ret); 204 return ret; 205 } 206 207 init_completion(&fw->c); 208 209 platform_set_drvdata(pdev, fw); 210 211 rpi_firmware_print_firmware_revision(fw); 212 213 return 0; 214 } 215 216 static int rpi_firmware_remove(struct platform_device *pdev) 217 { 218 struct rpi_firmware *fw = platform_get_drvdata(pdev); 219 220 mbox_free_channel(fw->chan); 221 222 return 0; 223 } 224 225 /** 226 * rpi_firmware_get - Get pointer to rpi_firmware structure. 227 * @firmware_node: Pointer to the firmware Device Tree node. 228 * 229 * Returns NULL is the firmware device is not ready. 230 */ 231 struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node) 232 { 233 struct platform_device *pdev = of_find_device_by_node(firmware_node); 234 235 if (!pdev) 236 return NULL; 237 238 return platform_get_drvdata(pdev); 239 } 240 EXPORT_SYMBOL_GPL(rpi_firmware_get); 241 242 static const struct of_device_id rpi_firmware_of_match[] = { 243 { .compatible = "raspberrypi,bcm2835-firmware", }, 244 {}, 245 }; 246 MODULE_DEVICE_TABLE(of, rpi_firmware_of_match); 247 248 static struct platform_driver rpi_firmware_driver = { 249 .driver = { 250 .name = "raspberrypi-firmware", 251 .of_match_table = rpi_firmware_of_match, 252 }, 253 .probe = rpi_firmware_probe, 254 .remove = rpi_firmware_remove, 255 }; 256 module_platform_driver(rpi_firmware_driver); 257 258 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>"); 259 MODULE_DESCRIPTION("Raspberry Pi firmware driver"); 260 MODULE_LICENSE("GPL v2"); 261