drivers/firmware/sigma.c

   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/module.h>
  15 #include <linux/sigma.h>
  16 #include <linux/export.h>
  17
  18 /* Return: 0==OK, <0==error, =1 ==no more actions */
  19 static int
  20 process_sigma_action(struct i2c_client *client, struct sigma_firmware *ssfw)
  21 {
  22         struct sigma_action *sa = (void *)(ssfw->fw->data + ssfw->pos);
  23         size_t len = sigma_action_len(sa);
  24         int ret = 0;
  25
  26         pr_debug("%s: instr:%i addr:%#x len:%zu\n", __func__,
  27                 sa->instr, sa->addr, len);
  28
  29         switch (sa->instr) {
  30         case SIGMA_ACTION_WRITEXBYTES:
  31         case SIGMA_ACTION_WRITESINGLE:
  32         case SIGMA_ACTION_WRITESAFELOAD:
  33                 if (ssfw->fw->size < ssfw->pos + len)
  34                         return -EINVAL;
  35                 ret = i2c_master_send(client, (void *)&sa->addr, len);
  36                 if (ret < 0)
  37                         return -EINVAL;
  38                 break;
  39
  40         case SIGMA_ACTION_DELAY:
  41                 ret = 0;
  42                 udelay(len);
  43                 len = 0;
  44                 break;
  45
  46         case SIGMA_ACTION_END:
  47                 return 1;
  48
  49         default:
  50                 return -EINVAL;
  51         }
  52
  53         /* when arrive here ret=0 or sent data */
  54         ssfw->pos += sigma_action_size(sa, len);
  55         return ssfw->pos == ssfw->fw->size;
  56 }
  57
  58 static int
  59 process_sigma_actions(struct i2c_client *client, struct sigma_firmware *ssfw)
  60 {
  61         pr_debug("%s: processing %p\n", __func__, ssfw);
  62
  63         while (1) {
  64                 int ret = process_sigma_action(client, ssfw);
  65                 pr_debug("%s: action returned %i\n", __func__, ret);
  66                 if (ret == 1)
  67                         return 0;
  68                 else if (ret)
  69                         return ret;
  70         }
  71 }
  72
  73 int process_sigma_firmware(struct i2c_client *client, const char *name)
  74 {
  75         int ret;
  76         struct sigma_firmware_header *ssfw_head;
  77         struct sigma_firmware ssfw;
  78         const struct firmware *fw;
  79         u32 crc;
  80
  81         pr_debug("%s: loading firmware %s\n", __func__, name);
  82
  83         /* first load the blob */
  84         ret = request_firmware(&fw, name, &client->dev);
  85         if (ret) {
  86                 pr_debug("%s: request_firmware() failed with %i\n", __func__, ret);
  87                 return ret;
  88         }
  89         ssfw.fw = fw;
  90
  91         /* then verify the header */
  92         ret = -EINVAL;
  93         if (fw->size < sizeof(*ssfw_head))
  94                 goto done;
  95
  96         ssfw_head = (void *)fw->data;
  97         if (memcmp(ssfw_head->magic, SIGMA_MAGIC, ARRAY_SIZE(ssfw_head->magic)))
  98                 goto done;
  99
 100         crc = crc32(0, fw->data, fw->size);
 101         pr_debug("%s: crc=%x\n", __func__, crc);
 102         if (crc != ssfw_head->crc)
 103                 goto done;
 104
 105         ssfw.pos = sizeof(*ssfw_head);
 106
 107         /* finally process all of the actions */
 108         ret = process_sigma_actions(client, &ssfw);
 109
 110  done:
 111         release_firmware(fw);
 112
 113         pr_debug("%s: loaded %s\n", __func__, name);
 114
 115         return ret;
 116 }
 117 EXPORT_SYMBOL(process_sigma_firmware);
 118
 119 MODULE_LICENSE("GPL");