sound/soc/codecs/sigmadsp.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
  16 #include "sigmadsp.h"
  17
  18 static size_t sigma_action_size(struct sigma_action *sa)
  19 {
  20         size_t payload = 0;
  21
  22         switch (sa->instr) {
  23         case SIGMA_ACTION_WRITEXBYTES:
  24         case SIGMA_ACTION_WRITESINGLE:
  25         case SIGMA_ACTION_WRITESAFELOAD:
  26                 payload = sigma_action_len(sa);
  27                 break;
  28         default:
  29                 break;
  30         }
  31
  32         payload = ALIGN(payload, 2);
  33
  34         return payload + sizeof(struct sigma_action);
  35 }
  36
  37 /*
  38  * Returns a negative error value in case of an error, 0 if processing of
  39  * the firmware should be stopped after this action, 1 otherwise.
  40  */
  41 static int
  42 process_sigma_action(struct i2c_client *client, struct sigma_action *sa)
  43 {
  44         size_t len = sigma_action_len(sa);
  45         int ret;
  46
  47         pr_debug("%s: instr:%i addr:%#x len:%zu\n", __func__,
  48                 sa->instr, sa->addr, len);
  49
  50         switch (sa->instr) {
  51         case SIGMA_ACTION_WRITEXBYTES:
  52         case SIGMA_ACTION_WRITESINGLE:
  53         case SIGMA_ACTION_WRITESAFELOAD:
  54                 ret = i2c_master_send(client, (void *)&sa->addr, len);
  55                 if (ret < 0)
  56                         return -EINVAL;
  57                 break;
  58         case SIGMA_ACTION_DELAY:
  59                 udelay(len);
  60                 len = 0;
  61                 break;
  62         case SIGMA_ACTION_END:
  63                 return 0;
  64         default:
  65                 return -EINVAL;
  66         }
  67
  68         return 1;
  69 }
  70
  71 static int
  72 process_sigma_actions(struct i2c_client *client, struct sigma_firmware *ssfw)
  73 {
  74         struct sigma_action *sa;
  75         size_t size;
  76         int ret;
  77
  78         while (ssfw->pos + sizeof(*sa) <= ssfw->fw->size) {
  79                 sa = (struct sigma_action *)(ssfw->fw->data + ssfw->pos);
  80
  81                 size = sigma_action_size(sa);
  82                 ssfw->pos += size;
  83                 if (ssfw->pos > ssfw->fw->size || size == 0)
  84                         break;
  85
  86                 ret = process_sigma_action(client, sa);
  87
  88                 pr_debug("%s: action returned %i\n", __func__, ret);
  89
  90                 if (ret <= 0)
  91                         return ret;
  92         }
  93
  94         if (ssfw->pos != ssfw->fw->size)
  95                 return -EINVAL;
  96
  97         return 0;
  98 }
  99
 100 int process_sigma_firmware(struct i2c_client *client, const char *name)
 101 {
 102         int ret;
 103         struct sigma_firmware_header *ssfw_head;
 104         struct sigma_firmware ssfw;
 105         const struct firmware *fw;
 106         u32 crc;
 107
 108         pr_debug("%s: loading firmware %s\n", __func__, name);
 109
 110         /* first load the blob */
 111         ret = request_firmware(&fw, name, &client->dev);
 112         if (ret) {
 113                 pr_debug("%s: request_firmware() failed with %i\n", __func__, ret);
 114                 return ret;
 115         }
 116         ssfw.fw = fw;
 117
 118         /* then verify the header */
 119         ret = -EINVAL;
 120
 121         /*
 122          * Reject too small or unreasonable large files. The upper limit has been
 123          * chosen a bit arbitrarily, but it should be enough for all practical
 124          * purposes and having the limit makes it easier to avoid integer
 125          * overflows later in the loading process.
 126          */
 127         if (fw->size < sizeof(*ssfw_head) || fw->size >= 0x4000000)
 128                 goto done;
 129
 130         ssfw_head = (void *)fw->data;
 131         if (memcmp(ssfw_head->magic, SIGMA_MAGIC, ARRAY_SIZE(ssfw_head->magic)))
 132                 goto done;
 133
 134         crc = crc32(0, fw->data + sizeof(*ssfw_head),
 135                         fw->size - sizeof(*ssfw_head));
 136         pr_debug("%s: crc=%x\n", __func__, crc);
 137         if (crc != le32_to_cpu(ssfw_head->crc))
 138                 goto done;
 139
 140         ssfw.pos = sizeof(*ssfw_head);
 141
 142         /* finally process all of the actions */
 143         ret = process_sigma_actions(client, &ssfw);
 144
 145  done:
 146         release_firmware(fw);
 147
 148         pr_debug("%s: loaded %s\n", __func__, name);
 149
 150         return ret;
 151 }
 152 EXPORT_SYMBOL(process_sigma_firmware);
 153
 154 MODULE_LICENSE("GPL");