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| 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 | + time_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 <[email protected]>"); |
| 259 | +MODULE_DESCRIPTION("Raspberry Pi firmware driver"); |
| 260 | +MODULE_LICENSE("GPL v2"); |
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