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