drivers/misc/i2c_eeprom_emul.c

   1 /*
   2  * Simulate an I2C eeprom
   3  *
   4  * Copyright (c) 2014 Google, Inc
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <dm.h>
  11 #include <errno.h>
  12 #include <i2c.h>
  13 #include <malloc.h>
  14 #include <asm/test.h>
  15
  16 #ifdef DEBUG
  17 #define debug_buffer print_buffer
  18 #else
  19 #define debug_buffer(x, ...)
  20 #endif
  21
  22 DECLARE_GLOBAL_DATA_PTR;
  23
  24 struct sandbox_i2c_flash_plat_data {
  25         enum sandbox_i2c_eeprom_test_mode test_mode;
  26         const char *filename;
  27         int offset_len;         /* Length of an offset in bytes */
  28         int size;               /* Size of data buffer */
  29 };
  30
  31 struct sandbox_i2c_flash {
  32         uint8_t *data;
  33 };
  34
  35 void sandbox_i2c_eeprom_set_test_mode(struct udevice *dev,
  36                                       enum sandbox_i2c_eeprom_test_mode mode)
  37 {
  38         struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
  39
  40         plat->test_mode = mode;
  41 }
  42
  43 void sandbox_i2c_eeprom_set_offset_len(struct udevice *dev, int offset_len)
  44 {
  45         struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
  46
  47         plat->offset_len = offset_len;
  48 }
  49
  50 static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
  51                                   int nmsgs)
  52 {
  53         struct sandbox_i2c_flash *priv = dev_get_priv(emul);
  54         uint offset = 0;
  55
  56         debug("\n%s\n", __func__);
  57         debug_buffer(0, priv->data, 1, 16, 0);
  58         for (; nmsgs > 0; nmsgs--, msg++) {
  59                 struct sandbox_i2c_flash_plat_data *plat =
  60                                 dev_get_platdata(emul);
  61                 int len;
  62                 u8 *ptr;
  63
  64                 if (!plat->size)
  65                         return -ENODEV;
  66                 if (msg->addr + msg->len > plat->size) {
  67                         debug("%s: Address %x, len %x is outside range 0..%x\n",
  68                               __func__, msg->addr, msg->len, plat->size);
  69                         return -EINVAL;
  70                 }
  71                 len = msg->len;
  72                 debug("   %s: msg->len=%d",
  73                       msg->flags & I2C_M_RD ? "read" : "write",
  74                       msg->len);
  75                 if (msg->flags & I2C_M_RD) {
  76                         if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
  77                                 len = 1;
  78                         debug(", offset %x, len %x: ", offset, len);
  79                         memcpy(msg->buf, priv->data + offset, len);
  80                         memset(msg->buf + len, '\xff', msg->len - len);
  81                         debug_buffer(0, msg->buf, 1, msg->len, 0);
  82                 } else if (len >= plat->offset_len) {
  83                         int i;
  84
  85                         ptr = msg->buf;
  86                         for (i = 0; i < plat->offset_len; i++, len--)
  87                                 offset = (offset << 8) | *ptr++;
  88                         debug(", set offset %x: ", offset);
  89                         debug_buffer(0, msg->buf, 1, msg->len, 0);
  90                         if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
  91                                 len = min(len, 1);
  92
  93                         /* For testing, map offsets into our limited buffer */
  94                         for (i = 24; i > 0; i -= 8) {
  95                                 if (offset > (1 << i)) {
  96                                         offset = (offset >> i) |
  97                                                 (offset & ((1 << i) - 1));
  98                                         offset += i;
  99                                 }
 100                         }
 101                         memcpy(priv->data + offset, ptr, len);
 102                 }
 103         }
 104         debug_buffer(0, priv->data, 1, 16, 0);
 105
 106         return 0;
 107 }
 108
 109 struct dm_i2c_ops sandbox_i2c_emul_ops = {
 110         .xfer = sandbox_i2c_eeprom_xfer,
 111 };
 112
 113 static int sandbox_i2c_eeprom_ofdata_to_platdata(struct udevice *dev)
 114 {
 115         struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
 116
 117         plat->size = dev_read_u32_default(dev, "sandbox,size", 32);
 118         plat->filename = dev_read_string(dev, "sandbox,filename");
 119         if (!plat->filename) {
 120                 debug("%s: No filename for device '%s'\n", __func__,
 121                       dev->name);
 122                 return -EINVAL;
 123         }
 124         plat->test_mode = SIE_TEST_MODE_NONE;
 125         plat->offset_len = 1;
 126
 127         return 0;
 128 }
 129
 130 static int sandbox_i2c_eeprom_probe(struct udevice *dev)
 131 {
 132         struct sandbox_i2c_flash_plat_data *plat = dev_get_platdata(dev);
 133         struct sandbox_i2c_flash *priv = dev_get_priv(dev);
 134
 135         priv->data = calloc(1, plat->size);
 136         if (!priv->data)
 137                 return -ENOMEM;
 138
 139         return 0;
 140 }
 141
 142 static int sandbox_i2c_eeprom_remove(struct udevice *dev)
 143 {
 144         struct sandbox_i2c_flash *priv = dev_get_priv(dev);
 145
 146         free(priv->data);
 147
 148         return 0;
 149 }
 150
 151 static const struct udevice_id sandbox_i2c_ids[] = {
 152         { .compatible = "sandbox,i2c-eeprom" },
 153         { }
 154 };
 155
 156 U_BOOT_DRIVER(sandbox_i2c_emul) = {
 157         .name           = "sandbox_i2c_eeprom_emul",
 158         .id             = UCLASS_I2C_EMUL,
 159         .of_match       = sandbox_i2c_ids,
 160         .ofdata_to_platdata = sandbox_i2c_eeprom_ofdata_to_platdata,
 161         .probe          = sandbox_i2c_eeprom_probe,
 162         .remove         = sandbox_i2c_eeprom_remove,
 163         .priv_auto_alloc_size = sizeof(struct sandbox_i2c_flash),
 164         .platdata_auto_alloc_size = sizeof(struct sandbox_i2c_flash_plat_data),
 165         .ops            = &sandbox_i2c_emul_ops,
 166 };