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/sigma.h>
  15
  16 /* Return: 0==OK, <0==error, =1 ==no more actions */
  17 static int
  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
  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
  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);