Commit | Line | Data |
---|---|---|
4e3d6065 EA |
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 | ||
a1547e0b KC |
24 | #define MAX_RPI_FW_PROP_BUF_SIZE 32 |
25 | ||
70eea1bb SW |
26 | static struct platform_device *rpi_hwmon; |
27 | ||
4e3d6065 EA |
28 | struct rpi_firmware { |
29 | struct mbox_client cl; | |
30 | struct mbox_chan *chan; /* The property channel. */ | |
31 | struct completion c; | |
32 | u32 enabled; | |
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) { | |
59 | wait_for_completion(&fw->c); | |
60 | ret = 0; | |
61 | } else { | |
62 | dev_err(fw->cl.dev, "mbox_send_message returned %d\n", ret); | |
63 | } | |
64 | mutex_unlock(&transaction_lock); | |
65 | ||
66 | return ret; | |
67 | } | |
68 | ||
69 | /** | |
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. | |
74 | * | |
75 | * Submits a set of concatenated tags to the VPU firmware through the | |
76 | * mailbox property interface. | |
77 | * | |
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 | |
81 | * structure. | |
82 | */ | |
83 | int rpi_firmware_property_list(struct rpi_firmware *fw, | |
84 | void *data, size_t tag_size) | |
85 | { | |
86 | size_t size = tag_size + 12; | |
87 | u32 *buf; | |
88 | dma_addr_t bus_addr; | |
89 | int ret; | |
90 | ||
91 | /* Packets are processed a dword at a time. */ | |
92 | if (size & 3) | |
93 | return -EINVAL; | |
94 | ||
95 | buf = dma_alloc_coherent(fw->cl.dev, PAGE_ALIGN(size), &bus_addr, | |
96 | GFP_ATOMIC); | |
97 | if (!buf) | |
98 | return -ENOMEM; | |
99 | ||
100 | /* The firmware will error out without parsing in this case. */ | |
101 | WARN_ON(size >= 1024 * 1024); | |
102 | ||
103 | buf[0] = size; | |
104 | buf[1] = RPI_FIRMWARE_STATUS_REQUEST; | |
105 | memcpy(&buf[2], data, tag_size); | |
106 | buf[size / 4 - 1] = RPI_FIRMWARE_PROPERTY_END; | |
107 | wmb(); | |
108 | ||
109 | ret = rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_addr); | |
110 | ||
111 | rmb(); | |
112 | memcpy(data, &buf[2], tag_size); | |
113 | if (ret == 0 && buf[1] != RPI_FIRMWARE_STATUS_SUCCESS) { | |
114 | /* | |
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. | |
118 | */ | |
119 | dev_err(fw->cl.dev, "Request 0x%08x returned status 0x%08x\n", | |
120 | buf[2], buf[1]); | |
121 | ret = -EINVAL; | |
122 | } | |
123 | ||
124 | dma_free_coherent(fw->cl.dev, PAGE_ALIGN(size), buf, bus_addr); | |
125 | ||
126 | return ret; | |
127 | } | |
128 | EXPORT_SYMBOL_GPL(rpi_firmware_property_list); | |
129 | ||
130 | /** | |
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. | |
136 | * | |
137 | * Submits a single tag to the VPU firmware through the mailbox | |
138 | * property interface. | |
139 | * | |
140 | * This is a convenience wrapper around | |
141 | * rpi_firmware_property_list() to avoid some of the | |
142 | * boilerplate in property calls. | |
143 | */ | |
144 | int rpi_firmware_property(struct rpi_firmware *fw, | |
145 | u32 tag, void *tag_data, size_t buf_size) | |
146 | { | |
147 | /* Single tags are very small (generally 8 bytes), so the | |
148 | * stack should be safe. | |
149 | */ | |
a1547e0b KC |
150 | u8 data[sizeof(struct rpi_firmware_property_tag_header) + |
151 | MAX_RPI_FW_PROP_BUF_SIZE]; | |
4e3d6065 EA |
152 | struct rpi_firmware_property_tag_header *header = |
153 | (struct rpi_firmware_property_tag_header *)data; | |
154 | int ret; | |
155 | ||
a1547e0b KC |
156 | if (WARN_ON(buf_size > sizeof(data) - sizeof(*header))) |
157 | return -EINVAL; | |
158 | ||
4e3d6065 EA |
159 | header->tag = tag; |
160 | header->buf_size = buf_size; | |
161 | header->req_resp_size = 0; | |
162 | memcpy(data + sizeof(struct rpi_firmware_property_tag_header), | |
163 | tag_data, buf_size); | |
164 | ||
a1547e0b | 165 | ret = rpi_firmware_property_list(fw, &data, buf_size + sizeof(*header)); |
4e3d6065 EA |
166 | memcpy(tag_data, |
167 | data + sizeof(struct rpi_firmware_property_tag_header), | |
168 | buf_size); | |
169 | ||
170 | return ret; | |
171 | } | |
172 | EXPORT_SYMBOL_GPL(rpi_firmware_property); | |
173 | ||
174 | static void | |
175 | rpi_firmware_print_firmware_revision(struct rpi_firmware *fw) | |
176 | { | |
177 | u32 packet; | |
178 | int ret = rpi_firmware_property(fw, | |
179 | RPI_FIRMWARE_GET_FIRMWARE_REVISION, | |
180 | &packet, sizeof(packet)); | |
181 | ||
182 | if (ret == 0) { | |
183 | struct tm tm; | |
184 | ||
9107ee6a | 185 | time64_to_tm(packet, 0, &tm); |
4e3d6065 EA |
186 | |
187 | dev_info(fw->cl.dev, | |
188 | "Attached to firmware from %04ld-%02d-%02d %02d:%02d\n", | |
189 | tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, | |
190 | tm.tm_hour, tm.tm_min); | |
191 | } | |
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 | ||
4e3d6065 EA |
208 | static int rpi_firmware_probe(struct platform_device *pdev) |
209 | { | |
210 | struct device *dev = &pdev->dev; | |
211 | struct rpi_firmware *fw; | |
212 | ||
213 | fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL); | |
214 | if (!fw) | |
215 | return -ENOMEM; | |
216 | ||
217 | fw->cl.dev = dev; | |
218 | fw->cl.rx_callback = response_callback; | |
219 | fw->cl.tx_block = true; | |
220 | ||
221 | fw->chan = mbox_request_channel(&fw->cl, 0); | |
222 | if (IS_ERR(fw->chan)) { | |
223 | int ret = PTR_ERR(fw->chan); | |
224 | if (ret != -EPROBE_DEFER) | |
225 | dev_err(dev, "Failed to get mbox channel: %d\n", ret); | |
226 | return ret; | |
227 | } | |
228 | ||
229 | init_completion(&fw->c); | |
230 | ||
231 | platform_set_drvdata(pdev, fw); | |
232 | ||
233 | rpi_firmware_print_firmware_revision(fw); | |
70eea1bb | 234 | rpi_register_hwmon_driver(dev, fw); |
4e3d6065 EA |
235 | |
236 | return 0; | |
237 | } | |
238 | ||
239 | static int rpi_firmware_remove(struct platform_device *pdev) | |
240 | { | |
241 | struct rpi_firmware *fw = platform_get_drvdata(pdev); | |
242 | ||
70eea1bb SW |
243 | platform_device_unregister(rpi_hwmon); |
244 | rpi_hwmon = NULL; | |
4e3d6065 EA |
245 | mbox_free_channel(fw->chan); |
246 | ||
247 | return 0; | |
248 | } | |
249 | ||
250 | /** | |
251 | * rpi_firmware_get - Get pointer to rpi_firmware structure. | |
252 | * @firmware_node: Pointer to the firmware Device Tree node. | |
253 | * | |
254 | * Returns NULL is the firmware device is not ready. | |
255 | */ | |
256 | struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node) | |
257 | { | |
258 | struct platform_device *pdev = of_find_device_by_node(firmware_node); | |
259 | ||
260 | if (!pdev) | |
261 | return NULL; | |
262 | ||
263 | return platform_get_drvdata(pdev); | |
264 | } | |
265 | EXPORT_SYMBOL_GPL(rpi_firmware_get); | |
266 | ||
267 | static const struct of_device_id rpi_firmware_of_match[] = { | |
268 | { .compatible = "raspberrypi,bcm2835-firmware", }, | |
269 | {}, | |
270 | }; | |
271 | MODULE_DEVICE_TABLE(of, rpi_firmware_of_match); | |
272 | ||
273 | static struct platform_driver rpi_firmware_driver = { | |
274 | .driver = { | |
275 | .name = "raspberrypi-firmware", | |
276 | .of_match_table = rpi_firmware_of_match, | |
277 | }, | |
278 | .probe = rpi_firmware_probe, | |
279 | .remove = rpi_firmware_remove, | |
280 | }; | |
281 | module_platform_driver(rpi_firmware_driver); | |
282 | ||
283 | MODULE_AUTHOR("Eric Anholt <eric@anholt.net>"); | |
284 | MODULE_DESCRIPTION("Raspberry Pi firmware driver"); | |
285 | MODULE_LICENSE("GPL v2"); |