1 /*
2  * Load Analog Devices SigmaStudio firmware files
3  *
4  * Copyright 2009-2011 Analog Devices Inc.
5  *
6  * Licensed under the GPL-2 or later.
7  */
8 
9 #include <linux/crc32.h>
10 #include <linux/delay.h>
11 #include <linux/firmware.h>
12 #include <linux/kernel.h>
13 #include <linux/i2c.h>
14 #include <linux/sigma.h>
15 
16 /* Return: 0==OK, <0==error, =1 ==no more actions */
17 static int
process_sigma_action(struct i2c_client * client,struct sigma_firmware * ssfw)18 process_sigma_action(struct i2c_client *client, struct sigma_firmware *ssfw)
19 {
20 	struct sigma_action *sa = (void *)(ssfw->fw->data + ssfw->pos);
21 	size_t len = sigma_action_len(sa);
22 	int ret = 0;
23 
24 	pr_debug("%s: instr:%i addr:%#x len:%zu\n", __func__,
25 		sa->instr, sa->addr, len);
26 
27 	switch (sa->instr) {
28 	case SIGMA_ACTION_WRITEXBYTES:
29 	case SIGMA_ACTION_WRITESINGLE:
30 	case SIGMA_ACTION_WRITESAFELOAD:
31 		if (ssfw->fw->size < ssfw->pos + len)
32 			return -EINVAL;
33 		ret = i2c_master_send(client, (void *)&sa->addr, len);
34 		if (ret < 0)
35 			return -EINVAL;
36 		break;
37 
38 	case SIGMA_ACTION_DELAY:
39 		ret = 0;
40 		udelay(len);
41 		len = 0;
42 		break;
43 
44 	case SIGMA_ACTION_END:
45 		return 1;
46 
47 	default:
48 		return -EINVAL;
49 	}
50 
51 	/* when arrive here ret=0 or sent data */
52 	ssfw->pos += sigma_action_size(sa, len);
53 	return ssfw->pos == ssfw->fw->size;
54 }
55 
56 static int
process_sigma_actions(struct i2c_client * client,struct sigma_firmware * ssfw)57 process_sigma_actions(struct i2c_client *client, struct sigma_firmware *ssfw)
58 {
59 	pr_debug("%s: processing %p\n", __func__, ssfw);
60 
61 	while (1) {
62 		int ret = process_sigma_action(client, ssfw);
63 		pr_debug("%s: action returned %i\n", __func__, ret);
64 		if (ret == 1)
65 			return 0;
66 		else if (ret)
67 			return ret;
68 	}
69 }
70 
process_sigma_firmware(struct i2c_client * client,const char * name)71 int process_sigma_firmware(struct i2c_client *client, const char *name)
72 {
73 	int ret;
74 	struct sigma_firmware_header *ssfw_head;
75 	struct sigma_firmware ssfw;
76 	const struct firmware *fw;
77 	u32 crc;
78 
79 	pr_debug("%s: loading firmware %s\n", __func__, name);
80 
81 	/* first load the blob */
82 	ret = request_firmware(&fw, name, &client->dev);
83 	if (ret) {
84 		pr_debug("%s: request_firmware() failed with %i\n", __func__, ret);
85 		return ret;
86 	}
87 	ssfw.fw = fw;
88 
89 	/* then verify the header */
90 	ret = -EINVAL;
91 	if (fw->size < sizeof(*ssfw_head))
92 		goto done;
93 
94 	ssfw_head = (void *)fw->data;
95 	if (memcmp(ssfw_head->magic, SIGMA_MAGIC, ARRAY_SIZE(ssfw_head->magic)))
96 		goto done;
97 
98 	crc = crc32(0, fw->data, fw->size);
99 	pr_debug("%s: crc=%x\n", __func__, crc);
100 	if (crc != ssfw_head->crc)
101 		goto done;
102 
103 	ssfw.pos = sizeof(*ssfw_head);
104 
105 	/* finally process all of the actions */
106 	ret = process_sigma_actions(client, &ssfw);
107 
108  done:
109 	release_firmware(fw);
110 
111 	pr_debug("%s: loaded %s\n", __func__, name);
112 
113 	return ret;
114 }
115 EXPORT_SYMBOL(process_sigma_firmware);
116