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502b431c | 1 | // SPDX-License-Identifier: GPL-2.0 |
4e3d6065 | 2 | /* |
60aa8782 | 3 | * Defines interfaces for interacting with the Raspberry Pi firmware's |
4e3d6065 EA |
4 | * property channel. |
5 | * | |
6 | * Copyright © 2015 Broadcom | |
4e3d6065 EA |
7 | */ |
8 | ||
9 | #include <linux/dma-mapping.h> | |
1e7c5735 | 10 | #include <linux/kref.h> |
4e3d6065 EA |
11 | #include <linux/mailbox_client.h> |
12 | #include <linux/module.h> | |
13 | #include <linux/of_platform.h> | |
14 | #include <linux/platform_device.h> | |
91c6ada6 | 15 | #include <linux/slab.h> |
4e3d6065 EA |
16 | #include <soc/bcm2835/raspberrypi-firmware.h> |
17 | ||
18 | #define MBOX_MSG(chan, data28) (((data28) & ~0xf) | ((chan) & 0xf)) | |
19 | #define MBOX_CHAN(msg) ((msg) & 0xf) | |
20 | #define MBOX_DATA28(msg) ((msg) & ~0xf) | |
21 | #define MBOX_CHAN_PROPERTY 8 | |
22 | ||
70eea1bb | 23 | static struct platform_device *rpi_hwmon; |
91f2cf4a | 24 | static struct platform_device *rpi_clk; |
70eea1bb | 25 | |
4e3d6065 EA |
26 | struct rpi_firmware { |
27 | struct mbox_client cl; | |
28 | struct mbox_chan *chan; /* The property channel. */ | |
29 | struct completion c; | |
30 | u32 enabled; | |
1e7c5735 NSJ |
31 | |
32 | struct kref consumers; | |
4e3d6065 EA |
33 | }; |
34 | ||
35 | static DEFINE_MUTEX(transaction_lock); | |
36 | ||
37 | static void response_callback(struct mbox_client *cl, void *msg) | |
38 | { | |
39 | struct rpi_firmware *fw = container_of(cl, struct rpi_firmware, cl); | |
40 | complete(&fw->c); | |
41 | } | |
42 | ||
43 | /* | |
44 | * Sends a request to the firmware through the BCM2835 mailbox driver, | |
45 | * and synchronously waits for the reply. | |
46 | */ | |
47 | static int | |
48 | rpi_firmware_transaction(struct rpi_firmware *fw, u32 chan, u32 data) | |
49 | { | |
50 | u32 message = MBOX_MSG(chan, data); | |
51 | int ret; | |
52 | ||
53 | WARN_ON(data & 0xf); | |
54 | ||
55 | mutex_lock(&transaction_lock); | |
56 | reinit_completion(&fw->c); | |
57 | ret = mbox_send_message(fw->chan, &message); | |
58 | if (ret >= 0) { | |
0829187b SW |
59 | if (wait_for_completion_timeout(&fw->c, HZ)) { |
60 | ret = 0; | |
61 | } else { | |
62 | ret = -ETIMEDOUT; | |
63 | WARN_ONCE(1, "Firmware transaction timeout"); | |
64 | } | |
4e3d6065 EA |
65 | } else { |
66 | dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret); | |
67 | } | |
68 | mutex_unlock(&transaction_lock); | |
69 | ||
70 | return ret; | |
71 | } | |
72 | ||
73 | /** | |
74 | * rpi_firmware_property_list - Submit firmware property list | |
75 | * @fw: Pointer to firmware structure from rpi_firmware_get(). | |
76 | * @data: Buffer holding tags. | |
77 | * @tag_size: Size of tags buffer. | |
78 | * | |
79 | * Submits a set of concatenated tags to the VPU firmware through the | |
80 | * mailbox property interface. | |
81 | * | |
82 | * The buffer header and the ending tag are added by this function and | |
83 | * don't need to be supplied, just the actual tags for your operation. | |
84 | * See struct rpi_firmware_property_tag_header for the per-tag | |
85 | * structure. | |
86 | */ | |
87 | int rpi_firmware_property_list(struct rpi_firmware *fw, | |
88 | void *data, size_t tag_size) | |
89 | { | |
90 | size_t size = tag_size + 12; | |
91 | u32 *buf; | |
92 | dma_addr_t bus_addr; | |
93 | int ret; | |
94 | ||
95 | /* Packets are processed a dword at a time. */ | |
96 | if (size & 3) | |
97 | return -EINVAL; | |
98 | ||
99 | buf = dma_alloc_coherent(fw->cl.dev, PAGE_ALIGN(size), &bus_addr, | |
100 | GFP_ATOMIC); | |
101 | if (!buf) | |
102 | return -ENOMEM; | |
103 | ||
104 | /* The firmware will error out without parsing in this case. */ | |
105 | WARN_ON(size >= 1024 * 1024); | |
106 | ||
107 | buf[0] = size; | |
108 | buf[1] = RPI_FIRMWARE_STATUS_REQUEST; | |
109 | memcpy(&buf[2], data, tag_size); | |
110 | buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END; | |
111 | wmb(); | |
112 | ||
113 | ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr); | |
114 | ||
115 | rmb(); | |
116 | memcpy(data, &buf[2], tag_size); | |
117 | if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) { | |
118 | /* | |
119 | * The tag name here might not be the one causing the | |
120 | * error, if there were multiple tags in the request. | |
121 | * But single-tag is the most common, so go with it. | |
122 | */ | |
123 | dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n", | |
124 | buf[2], buf[1]); | |
125 | ret = -EINVAL; | |
126 | } | |
127 | ||
128 | dma_free_coherent(fw->cl.dev, PAGE_ALIGN(size), buf, bus_addr); | |
129 | ||
130 | return ret; | |
131 | } | |
132 | EXPORT_SYMBOL_GPL(rpi_firmware_property_list); | |
133 | ||
134 | /** | |
135 | * rpi_firmware_property - Submit single firmware property | |
136 | * @fw: Pointer to firmware structure from rpi_firmware_get(). | |
137 | * @tag: One of enum_mbox_property_tag. | |
138 | * @tag_data: Tag data buffer. | |
139 | * @buf_size: Buffer size. | |
140 | * | |
141 | * Submits a single tag to the VPU firmware through the mailbox | |
142 | * property interface. | |
143 | * | |
144 | * This is a convenience wrapper around | |
145 | * rpi_firmware_property_list() to avoid some of the | |
146 | * boilerplate in property calls. | |
147 | */ | |
148 | int rpi_firmware_property(struct rpi_firmware *fw, | |
149 | u32 tag, void *tag_data, size_t buf_size) | |
150 | { | |
91c6ada6 | 151 | struct rpi_firmware_property_tag_header *header; |
4e3d6065 EA |
152 | int ret; |
153 | ||
91c6ada6 JH |
154 | /* Some mailboxes can use over 1k bytes. Rather than checking |
155 | * size and using stack or kmalloc depending on requirements, | |
156 | * just use kmalloc. Mailboxes don't get called enough to worry | |
157 | * too much about the time taken in the allocation. | |
158 | */ | |
159 | void *data = kmalloc(sizeof(*header) + buf_size, GFP_KERNEL); | |
a1547e0b | 160 | |
91c6ada6 JH |
161 | if (!data) |
162 | return -ENOMEM; | |
163 | ||
164 | header = data; | |
4e3d6065 EA |
165 | header->tag = tag; |
166 | header->buf_size = buf_size; | |
167 | header->req_resp_size = 0; | |
91c6ada6 JH |
168 | memcpy(data + sizeof(*header), tag_data, buf_size); |
169 | ||
170 | ret = rpi_firmware_property_list(fw, data, buf_size + sizeof(*header)); | |
171 | ||
172 | memcpy(tag_data, data + sizeof(*header), buf_size); | |
4e3d6065 | 173 | |
91c6ada6 | 174 | kfree(data); |
4e3d6065 EA |
175 | |
176 | return ret; | |
177 | } | |
178 | EXPORT_SYMBOL_GPL(rpi_firmware_property); | |
179 | ||
180 | static void | |
181 | rpi_firmware_print_firmware_revision(struct rpi_firmware *fw) | |
182 | { | |
da785a87 | 183 | time64_t date_and_time; |
4e3d6065 EA |
184 | u32 packet; |
185 | int ret = rpi_firmware_property(fw, | |
186 | RPI_FIRMWARE_GET_FIRMWARE_REVISION, | |
187 | &packet, sizeof(packet)); | |
188 | ||
4a60f58e AS |
189 | if (ret) |
190 | return; | |
4e3d6065 | 191 | |
da785a87 AS |
192 | /* This is not compatible with y2038 */ |
193 | date_and_time = packet; | |
194 | dev_info(fw->cl.dev, "Attached to firmware from %ptT\n", &date_and_time); | |
4e3d6065 EA |
195 | } |
196 | ||
70eea1bb SW |
197 | static void |
198 | rpi_register_hwmon_driver(struct device *dev, struct rpi_firmware *fw) | |
199 | { | |
200 | u32 packet; | |
201 | int ret = rpi_firmware_property(fw, RPI_FIRMWARE_GET_THROTTLED, | |
202 | &packet, sizeof(packet)); | |
203 | ||
204 | if (ret) | |
205 | return; | |
206 | ||
207 | rpi_hwmon = platform_device_register_data(dev, "raspberrypi-hwmon", | |
208 | -1, NULL, 0); | |
209 | } | |
210 | ||
91f2cf4a NSJ |
211 | static void rpi_register_clk_driver(struct device *dev) |
212 | { | |
511aba09 MR |
213 | struct device_node *firmware; |
214 | ||
215 | /* | |
216 | * Earlier DTs don't have a node for the firmware clocks but | |
217 | * rely on us creating a platform device by hand. If we do | |
218 | * have a node for the firmware clocks, just bail out here. | |
219 | */ | |
220 | firmware = of_get_compatible_child(dev->of_node, | |
221 | "raspberrypi,firmware-clocks"); | |
222 | if (firmware) { | |
223 | of_node_put(firmware); | |
224 | return; | |
225 | } | |
226 | ||
91f2cf4a NSJ |
227 | rpi_clk = platform_device_register_data(dev, "raspberrypi-clk", |
228 | -1, NULL, 0); | |
229 | } | |
230 | ||
1e7c5735 NSJ |
231 | static void rpi_firmware_delete(struct kref *kref) |
232 | { | |
233 | struct rpi_firmware *fw = container_of(kref, struct rpi_firmware, | |
234 | consumers); | |
235 | ||
236 | mbox_free_channel(fw->chan); | |
237 | kfree(fw); | |
238 | } | |
239 | ||
240 | void rpi_firmware_put(struct rpi_firmware *fw) | |
241 | { | |
242 | kref_put(&fw->consumers, rpi_firmware_delete); | |
243 | } | |
244 | EXPORT_SYMBOL_GPL(rpi_firmware_put); | |
245 | ||
f663204c NSJ |
246 | static void devm_rpi_firmware_put(void *data) |
247 | { | |
248 | struct rpi_firmware *fw = data; | |
249 | ||
250 | rpi_firmware_put(fw); | |
251 | } | |
252 | ||
4e3d6065 EA |
253 | static int rpi_firmware_probe(struct platform_device *pdev) |
254 | { | |
255 | struct device *dev = &pdev->dev; | |
256 | struct rpi_firmware *fw; | |
257 | ||
1e7c5735 NSJ |
258 | /* |
259 | * Memory will be freed by rpi_firmware_delete() once all users have | |
260 | * released their firmware handles. Don't use devm_kzalloc() here. | |
261 | */ | |
262 | fw = kzalloc(sizeof(*fw), GFP_KERNEL); | |
4e3d6065 EA |
263 | if (!fw) |
264 | return -ENOMEM; | |
265 | ||
266 | fw->cl.dev = dev; | |
267 | fw->cl.rx_callback = response_callback; | |
268 | fw->cl.tx_block = true; | |
269 | ||
270 | fw->chan = mbox_request_channel(&fw->cl, 0); | |
271 | if (IS_ERR(fw->chan)) { | |
272 | int ret = PTR_ERR(fw->chan); | |
273 | if (ret != -EPROBE_DEFER) | |
274 | dev_err(dev, "Failed to get mbox channel: %d\n", ret); | |
275 | return ret; | |
276 | } | |
277 | ||
278 | init_completion(&fw->c); | |
1e7c5735 | 279 | kref_init(&fw->consumers); |
4e3d6065 EA |
280 | |
281 | platform_set_drvdata(pdev, fw); | |
282 | ||
283 | rpi_firmware_print_firmware_revision(fw); | |
70eea1bb | 284 | rpi_register_hwmon_driver(dev, fw); |
91f2cf4a | 285 | rpi_register_clk_driver(dev); |
4e3d6065 EA |
286 | |
287 | return 0; | |
288 | } | |
289 | ||
b80ec7c0 SW |
290 | static void rpi_firmware_shutdown(struct platform_device *pdev) |
291 | { | |
292 | struct rpi_firmware *fw = platform_get_drvdata(pdev); | |
293 | ||
294 | if (!fw) | |
295 | return; | |
296 | ||
297 | rpi_firmware_property(fw, RPI_FIRMWARE_NOTIFY_REBOOT, NULL, 0); | |
298 | } | |
299 | ||
4e3d6065 EA |
300 | static int rpi_firmware_remove(struct platform_device *pdev) |
301 | { | |
302 | struct rpi_firmware *fw = platform_get_drvdata(pdev); | |
303 | ||
70eea1bb SW |
304 | platform_device_unregister(rpi_hwmon); |
305 | rpi_hwmon = NULL; | |
91f2cf4a NSJ |
306 | platform_device_unregister(rpi_clk); |
307 | rpi_clk = NULL; | |
1e7c5735 NSJ |
308 | |
309 | rpi_firmware_put(fw); | |
4e3d6065 EA |
310 | |
311 | return 0; | |
312 | } | |
313 | ||
314 | /** | |
315 | * rpi_firmware_get - Get pointer to rpi_firmware structure. | |
316 | * @firmware_node: Pointer to the firmware Device Tree node. | |
317 | * | |
1e7c5735 NSJ |
318 | * The reference to rpi_firmware has to be released with rpi_firmware_put(). |
319 | * | |
4e3d6065 EA |
320 | * Returns NULL is the firmware device is not ready. |
321 | */ | |
322 | struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node) | |
323 | { | |
324 | struct platform_device *pdev = of_find_device_by_node(firmware_node); | |
1e7c5735 | 325 | struct rpi_firmware *fw; |
4e3d6065 EA |
326 | |
327 | if (!pdev) | |
328 | return NULL; | |
329 | ||
1e7c5735 NSJ |
330 | fw = platform_get_drvdata(pdev); |
331 | if (!fw) | |
09cbd1df | 332 | goto err_put_device; |
1e7c5735 NSJ |
333 | |
334 | if (!kref_get_unless_zero(&fw->consumers)) | |
09cbd1df CJ |
335 | goto err_put_device; |
336 | ||
337 | put_device(&pdev->dev); | |
1e7c5735 NSJ |
338 | |
339 | return fw; | |
09cbd1df CJ |
340 | |
341 | err_put_device: | |
342 | put_device(&pdev->dev); | |
343 | return NULL; | |
4e3d6065 EA |
344 | } |
345 | EXPORT_SYMBOL_GPL(rpi_firmware_get); | |
346 | ||
f663204c NSJ |
347 | /** |
348 | * devm_rpi_firmware_get - Get pointer to rpi_firmware structure. | |
349 | * @firmware_node: Pointer to the firmware Device Tree node. | |
350 | * | |
351 | * Returns NULL is the firmware device is not ready. | |
352 | */ | |
353 | struct rpi_firmware *devm_rpi_firmware_get(struct device *dev, | |
354 | struct device_node *firmware_node) | |
355 | { | |
356 | struct rpi_firmware *fw; | |
357 | ||
358 | fw = rpi_firmware_get(firmware_node); | |
359 | if (!fw) | |
360 | return NULL; | |
361 | ||
362 | if (devm_add_action_or_reset(dev, devm_rpi_firmware_put, fw)) | |
363 | return NULL; | |
364 | ||
365 | return fw; | |
366 | } | |
367 | EXPORT_SYMBOL_GPL(devm_rpi_firmware_get); | |
368 | ||
4e3d6065 EA |
369 | static const struct of_device_id rpi_firmware_of_match[] = { |
370 | { .compatible = "raspberrypi,bcm2835-firmware", }, | |
371 | {}, | |
372 | }; | |
373 | MODULE_DEVICE_TABLE(of, rpi_firmware_of_match); | |
374 | ||
375 | static struct platform_driver rpi_firmware_driver = { | |
376 | .driver = { | |
377 | .name = "raspberrypi-firmware", | |
378 | .of_match_table = rpi_firmware_of_match, | |
379 | }, | |
380 | .probe = rpi_firmware_probe, | |
b80ec7c0 | 381 | .shutdown = rpi_firmware_shutdown, |
4e3d6065 EA |
382 | .remove = rpi_firmware_remove, |
383 | }; | |
384 | module_platform_driver(rpi_firmware_driver); | |
385 | ||
386 | MODULE_AUTHOR("Eric Anholt <eric@anholt.net>"); | |
387 | MODULE_DESCRIPTION("Raspberry Pi firmware driver"); | |
388 | MODULE_LICENSE("GPL v2"); |