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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 | ||
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 <eric@anholt.net>"); | |
259 | MODULE_DESCRIPTION("Raspberry Pi firmware driver"); | |
260 | MODULE_LICENSE("GPL v2"); |