drivers/misc/i2c_eeprom_emul.c

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