1 // SPDX-License-Identifier: GPL-2.0
3 * Defines interfaces for interacting wtih the Raspberry Pi firmware's
6 * Copyright © 2015 Broadcom
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 <soc/bcm2835/raspberrypi-firmware.h>
17 #define MBOX_MSG(chan, data28) (((data28) & ~0xf) | ((chan) & 0xf))
18 #define MBOX_CHAN(msg) ((msg) & 0xf)
19 #define MBOX_DATA28(msg) ((msg) & ~0xf)
20 #define MBOX_CHAN_PROPERTY 8
22 static struct platform_device *rpi_hwmon;
25 struct mbox_client cl;
26 struct mbox_chan *chan; /* The property channel. */
31 static DEFINE_MUTEX(transaction_lock);
33 static void response_callback(struct mbox_client *cl, void *msg)
35 struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl);
40 * Sends a request to the firmware through the BCM2835 mailbox driver,
41 * and synchronously waits for the reply.
44 rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data)
46 u32 message = MBOX_MSG(chan, data);
51 mutex_lock(&transaction_lock);
52 reinit_completion(&fw->c);
53 ret = mbox_send_message(fw->chan, &message);
55 if (wait_for_completion_timeout(&fw->c, HZ)) {
59 WARN_ONCE(1, "Firmware transaction timeout");
62 dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret);
64 mutex_unlock(&transaction_lock);
70 * rpi_firmware_property_list - Submit firmware property list
71 * @fw: Pointer to firmware structure from rpi_firmware_get().
72 * @data: Buffer holding tags.
73 * @tag_size: Size of tags buffer.
75 * Submits a set of concatenated tags to the VPU firmware through the
76 * mailbox property interface.
78 * The buffer header and the ending tag are added by this function and
79 * don't need to be supplied, just the actual tags for your operation.
80 * See struct rpi_firmware_property_tag_header for the per-tag
83 int rpi_firmware_property_list(struct rpi_firmware *fw,
84 void *data, size_t tag_size)
86 size_t size = tag_size + 12;
91 /* Packets are processed a dword at a time. */
95 buf = dma_alloc_coherent(fw->cl.dev, PAGE_ALIGN(size), &bus_addr,
100 /* The firmware will error out without parsing in this case. */
101 WARN_ON(size >= 1024 * 1024);
104 buf[1] = RPI_FIRMWARE_STATUS_REQUEST;
105 memcpy(&buf[2], data, tag_size);
106 buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END;
109 ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr);
112 memcpy(data, &buf[2], tag_size);
113 if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) {
115 * The tag name here might not be the one causing the
116 * error, if there were multiple tags in the request.
117 * But single-tag is the most common, so go with it.
119 dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n",
124 dma_free_coherent(fw->cl.dev, PAGE_ALIGN(size), buf, bus_addr);
128 EXPORT_SYMBOL_GPL(rpi_firmware_property_list);
131 * rpi_firmware_property - Submit single firmware property
132 * @fw: Pointer to firmware structure from rpi_firmware_get().
133 * @tag: One of enum_mbox_property_tag.
134 * @tag_data: Tag data buffer.
135 * @buf_size: Buffer size.
137 * Submits a single tag to the VPU firmware through the mailbox
138 * property interface.
140 * This is a convenience wrapper around
141 * rpi_firmware_property_list() to avoid some of the
142 * boilerplate in property calls.
144 int rpi_firmware_property(struct rpi_firmware *fw,
145 u32 tag, void *tag_data, size_t buf_size)
147 struct rpi_firmware_property_tag_header *header;
150 /* Some mailboxes can use over 1k bytes. Rather than checking
151 * size and using stack or kmalloc depending on requirements,
152 * just use kmalloc. Mailboxes don't get called enough to worry
153 * too much about the time taken in the allocation.
155 void *data = kmalloc(sizeof(*header) + buf_size, GFP_KERNEL);
162 header->buf_size = buf_size;
163 header->req_resp_size = 0;
164 memcpy(data + sizeof(*header), tag_data, buf_size);
166 ret = rpi_firmware_property_list(fw, data, buf_size + sizeof(*header));
168 memcpy(tag_data, data + sizeof(*header), buf_size);
174 EXPORT_SYMBOL_GPL(rpi_firmware_property);
177 rpi_firmware_print_firmware_revision(struct rpi_firmware *fw)
180 int ret = rpi_firmware_property(fw,
181 RPI_FIRMWARE_GET_FIRMWARE_REVISION,
182 &packet, sizeof(packet));
187 time64_to_tm(packet, 0, &tm);
190 "Attached to firmware from %04ld-%02d-%02d %02d:%02d\n",
191 tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
192 tm.tm_hour, tm.tm_min);
197 rpi_register_hwmon_driver(struct device *dev, struct rpi_firmware *fw)
200 int ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_THROTTLED,
201 &packet, sizeof(packet));
206 rpi_hwmon = platform_device_register_data(dev, "raspberrypi-hwmon",
210 static int rpi_firmware_probe(struct platform_device *pdev)
212 struct device *dev = &pdev->dev;
213 struct rpi_firmware *fw;
215 fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL);
220 fw->cl.rx_callback = response_callback;
221 fw->cl.tx_block = true;
223 fw->chan = mbox_request_channel(&fw->cl, 0);
224 if (IS_ERR(fw->chan)) {
225 int ret = PTR_ERR(fw->chan);
226 if (ret != -EPROBE_DEFER)
227 dev_err(dev, "Failed to get mbox channel: %d\n", ret);
231 init_completion(&fw->c);
233 platform_set_drvdata(pdev, fw);
235 rpi_firmware_print_firmware_revision(fw);
236 rpi_register_hwmon_driver(dev, fw);
241 static int rpi_firmware_remove(struct platform_device *pdev)
243 struct rpi_firmware *fw = platform_get_drvdata(pdev);
245 platform_device_unregister(rpi_hwmon);
247 mbox_free_channel(fw->chan);
253 * rpi_firmware_get - Get pointer to rpi_firmware structure.
254 * @firmware_node: Pointer to the firmware Device Tree node.
256 * Returns NULL is the firmware device is not ready.
258 struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node)
260 struct platform_device *pdev = of_find_device_by_node(firmware_node);
265 return platform_get_drvdata(pdev);
267 EXPORT_SYMBOL_GPL(rpi_firmware_get);
269 static const struct of_device_id rpi_firmware_of_match[] = {
270 { .compatible = "raspberrypi,bcm2835-firmware", },
273 MODULE_DEVICE_TABLE(of, rpi_firmware_of_match);
275 static struct platform_driver rpi_firmware_driver = {
277 .name = "raspberrypi-firmware",
278 .of_match_table = rpi_firmware_of_match,
280 .probe = rpi_firmware_probe,
281 .remove = rpi_firmware_remove,
283 module_platform_driver(rpi_firmware_driver);
285 MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
286 MODULE_DESCRIPTION("Raspberry Pi firmware driver");
287 MODULE_LICENSE("GPL v2");