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