1/*
2 * Copyright (c) 2013 Broadcom Corporation
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
11 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
13 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
14 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17#include <linux/kernel.h>
18#include <linux/slab.h>
19#include <linux/device.h>
20#include <linux/firmware.h>
21#include <linux/module.h>
22
23#include "debug.h"
24#include "firmware.h"
25
26char brcmf_firmware_path[BRCMF_FW_PATH_LEN];
27module_param_string(firmware_path, brcmf_firmware_path,
28		    BRCMF_FW_PATH_LEN, 0440);
29
30enum nvram_parser_state {
31	IDLE,
32	KEY,
33	VALUE,
34	COMMENT,
35	END
36};
37
38/**
39 * struct nvram_parser - internal info for parser.
40 *
41 * @state: current parser state.
42 * @fwnv: input buffer being parsed.
43 * @nvram: output buffer with parse result.
44 * @nvram_len: lenght of parse result.
45 * @line: current line.
46 * @column: current column in line.
47 * @pos: byte offset in input buffer.
48 * @entry: start position of key,value entry.
49 */
50struct nvram_parser {
51	enum nvram_parser_state state;
52	const struct firmware *fwnv;
53	u8 *nvram;
54	u32 nvram_len;
55	u32 line;
56	u32 column;
57	u32 pos;
58	u32 entry;
59};
60
61static bool is_nvram_char(char c)
62{
63	/* comment marker excluded */
64	if (c == '#')
65		return false;
66
67	/* key and value may have any other readable character */
68	return (c > 0x20 && c < 0x7f);
69}
70
71static bool is_whitespace(char c)
72{
73	return (c == ' ' || c == '\r' || c == '\n' || c == '\t');
74}
75
76static enum nvram_parser_state brcmf_nvram_handle_idle(struct nvram_parser *nvp)
77{
78	char c;
79
80	c = nvp->fwnv->data[nvp->pos];
81	if (c == '\n')
82		return COMMENT;
83	if (is_whitespace(c))
84		goto proceed;
85	if (c == '#')
86		return COMMENT;
87	if (is_nvram_char(c)) {
88		nvp->entry = nvp->pos;
89		return KEY;
90	}
91	brcmf_dbg(INFO, "warning: ln=%d:col=%d: ignoring invalid character\n",
92		  nvp->line, nvp->column);
93proceed:
94	nvp->column++;
95	nvp->pos++;
96	return IDLE;
97}
98
99static enum nvram_parser_state brcmf_nvram_handle_key(struct nvram_parser *nvp)
100{
101	enum nvram_parser_state st = nvp->state;
102	char c;
103
104	c = nvp->fwnv->data[nvp->pos];
105	if (c == '=') {
106		/* ignore RAW1 by treating as comment */
107		if (strncmp(&nvp->fwnv->data[nvp->entry], "RAW1", 4) == 0)
108			st = COMMENT;
109		else
110			st = VALUE;
111	} else if (!is_nvram_char(c)) {
112		brcmf_dbg(INFO, "warning: ln=%d:col=%d: '=' expected, skip invalid key entry\n",
113			  nvp->line, nvp->column);
114		return COMMENT;
115	}
116
117	nvp->column++;
118	nvp->pos++;
119	return st;
120}
121
122static enum nvram_parser_state
123brcmf_nvram_handle_value(struct nvram_parser *nvp)
124{
125	char c;
126	char *skv;
127	char *ekv;
128	u32 cplen;
129
130	c = nvp->fwnv->data[nvp->pos];
131	if (!is_nvram_char(c)) {
132		/* key,value pair complete */
133		ekv = (u8 *)&nvp->fwnv->data[nvp->pos];
134		skv = (u8 *)&nvp->fwnv->data[nvp->entry];
135		cplen = ekv - skv;
136		/* copy to output buffer */
137		memcpy(&nvp->nvram[nvp->nvram_len], skv, cplen);
138		nvp->nvram_len += cplen;
139		nvp->nvram[nvp->nvram_len] = '\0';
140		nvp->nvram_len++;
141		return IDLE;
142	}
143	nvp->pos++;
144	nvp->column++;
145	return VALUE;
146}
147
148static enum nvram_parser_state
149brcmf_nvram_handle_comment(struct nvram_parser *nvp)
150{
151	char *eol, *sol;
152
153	sol = (char *)&nvp->fwnv->data[nvp->pos];
154	eol = strchr(sol, '\n');
155	if (eol == NULL)
156		return END;
157
158	/* eat all moving to next line */
159	nvp->line++;
160	nvp->column = 1;
161	nvp->pos += (eol - sol) + 1;
162	return IDLE;
163}
164
165static enum nvram_parser_state brcmf_nvram_handle_end(struct nvram_parser *nvp)
166{
167	/* final state */
168	return END;
169}
170
171static enum nvram_parser_state
172(*nv_parser_states[])(struct nvram_parser *nvp) = {
173	brcmf_nvram_handle_idle,
174	brcmf_nvram_handle_key,
175	brcmf_nvram_handle_value,
176	brcmf_nvram_handle_comment,
177	brcmf_nvram_handle_end
178};
179
180static int brcmf_init_nvram_parser(struct nvram_parser *nvp,
181				   const struct firmware *nv)
182{
183	memset(nvp, 0, sizeof(*nvp));
184	nvp->fwnv = nv;
185	/* Alloc for extra 0 byte + roundup by 4 + length field */
186	nvp->nvram = kzalloc(nv->size + 1 + 3 + sizeof(u32), GFP_KERNEL);
187	if (!nvp->nvram)
188		return -ENOMEM;
189
190	nvp->line = 1;
191	nvp->column = 1;
192	return 0;
193}
194
195/* brcmf_nvram_strip :Takes a buffer of "<var>=<value>\n" lines read from a fil
196 * and ending in a NUL. Removes carriage returns, empty lines, comment lines,
197 * and converts newlines to NULs. Shortens buffer as needed and pads with NULs.
198 * End of buffer is completed with token identifying length of buffer.
199 */
200static void *brcmf_fw_nvram_strip(const struct firmware *nv, u32 *new_length)
201{
202	struct nvram_parser nvp;
203	u32 pad;
204	u32 token;
205	__le32 token_le;
206
207	if (brcmf_init_nvram_parser(&nvp, nv) < 0)
208		return NULL;
209
210	while (nvp.pos < nv->size) {
211		nvp.state = nv_parser_states[nvp.state](&nvp);
212		if (nvp.state == END)
213			break;
214	}
215	pad = nvp.nvram_len;
216	*new_length = roundup(nvp.nvram_len + 1, 4);
217	while (pad != *new_length) {
218		nvp.nvram[pad] = 0;
219		pad++;
220	}
221
222	token = *new_length / 4;
223	token = (~token << 16) | (token & 0x0000FFFF);
224	token_le = cpu_to_le32(token);
225
226	memcpy(&nvp.nvram[*new_length], &token_le, sizeof(token_le));
227	*new_length += sizeof(token_le);
228
229	return nvp.nvram;
230}
231
232void brcmf_fw_nvram_free(void *nvram)
233{
234	kfree(nvram);
235}
236
237struct brcmf_fw {
238	struct device *dev;
239	u16 flags;
240	const struct firmware *code;
241	const char *nvram_name;
242	void (*done)(struct device *dev, const struct firmware *fw,
243		     void *nvram_image, u32 nvram_len);
244};
245
246static void brcmf_fw_request_nvram_done(const struct firmware *fw, void *ctx)
247{
248	struct brcmf_fw *fwctx = ctx;
249	u32 nvram_length = 0;
250	void *nvram = NULL;
251
252	brcmf_dbg(TRACE, "enter: dev=%s\n", dev_name(fwctx->dev));
253	if (!fw && !(fwctx->flags & BRCMF_FW_REQ_NV_OPTIONAL))
254		goto fail;
255
256	if (fw) {
257		nvram = brcmf_fw_nvram_strip(fw, &nvram_length);
258		release_firmware(fw);
259		if (!nvram && !(fwctx->flags & BRCMF_FW_REQ_NV_OPTIONAL))
260			goto fail;
261	}
262
263	fwctx->done(fwctx->dev, fwctx->code, nvram, nvram_length);
264	kfree(fwctx);
265	return;
266
267fail:
268	brcmf_dbg(TRACE, "failed: dev=%s\n", dev_name(fwctx->dev));
269	release_firmware(fwctx->code);
270	device_release_driver(fwctx->dev);
271	kfree(fwctx);
272}
273
274static void brcmf_fw_request_code_done(const struct firmware *fw, void *ctx)
275{
276	struct brcmf_fw *fwctx = ctx;
277	int ret;
278
279	brcmf_dbg(TRACE, "enter: dev=%s\n", dev_name(fwctx->dev));
280	if (!fw)
281		goto fail;
282
283	/* only requested code so done here */
284	if (!(fwctx->flags & BRCMF_FW_REQUEST_NVRAM)) {
285		fwctx->done(fwctx->dev, fw, NULL, 0);
286		kfree(fwctx);
287		return;
288	}
289	fwctx->code = fw;
290	ret = request_firmware_nowait(THIS_MODULE, true, fwctx->nvram_name,
291				      fwctx->dev, GFP_KERNEL, fwctx,
292				      brcmf_fw_request_nvram_done);
293
294	if (!ret)
295		return;
296
297	/* when nvram is optional call .done() callback here */
298	if (fwctx->flags & BRCMF_FW_REQ_NV_OPTIONAL) {
299		fwctx->done(fwctx->dev, fw, NULL, 0);
300		kfree(fwctx);
301		return;
302	}
303
304	/* failed nvram request */
305	release_firmware(fw);
306fail:
307	brcmf_dbg(TRACE, "failed: dev=%s\n", dev_name(fwctx->dev));
308	device_release_driver(fwctx->dev);
309	kfree(fwctx);
310}
311
312int brcmf_fw_get_firmwares(struct device *dev, u16 flags,
313			   const char *code, const char *nvram,
314			   void (*fw_cb)(struct device *dev,
315					 const struct firmware *fw,
316					 void *nvram_image, u32 nvram_len))
317{
318	struct brcmf_fw *fwctx;
319
320	brcmf_dbg(TRACE, "enter: dev=%s\n", dev_name(dev));
321	if (!fw_cb || !code)
322		return -EINVAL;
323
324	if ((flags & BRCMF_FW_REQUEST_NVRAM) && !nvram)
325		return -EINVAL;
326
327	fwctx = kzalloc(sizeof(*fwctx), GFP_KERNEL);
328	if (!fwctx)
329		return -ENOMEM;
330
331	fwctx->dev = dev;
332	fwctx->flags = flags;
333	fwctx->done = fw_cb;
334	if (flags & BRCMF_FW_REQUEST_NVRAM)
335		fwctx->nvram_name = nvram;
336
337	return request_firmware_nowait(THIS_MODULE, true, code, dev,
338				       GFP_KERNEL, fwctx,
339				       brcmf_fw_request_code_done);
340}
341