drivers/i2c/sandbox_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Simulate an I2C port
   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 <log.h>
  13 #include <asm/i2c.h>
  14 #include <asm/test.h>
  15 #include <dm/acpi.h>
  16 #include <dm/lists.h>
  17 #include <dm/device-internal.h>
  18
  19 static int get_emul(struct udevice *dev, struct udevice **devp,
  20                     struct dm_i2c_ops **opsp)
  21 {
  22         struct dm_i2c_chip *plat;
  23         int ret;
  24
  25         *devp = NULL;
  26         *opsp = NULL;
  27         plat = dev_get_parent_plat(dev);
  28         if (!plat->emul) {
  29                 ret = i2c_emul_find(dev, &plat->emul);
  30                 if (ret)
  31                         return ret;
  32         }
  33         *devp = plat->emul;
  34         *opsp = i2c_get_ops(plat->emul);
  35
  36         return 0;
  37 }
  38
  39 void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode)
  40 {
  41         struct sandbox_i2c_priv *priv = dev_get_priv(bus);
  42
  43         priv->test_mode = test_mode;
  44 }
  45
  46 static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
  47                             int nmsgs)
  48 {
  49         struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
  50         struct sandbox_i2c_priv *priv = dev_get_priv(bus);
  51         struct dm_i2c_ops *ops;
  52         struct udevice *emul, *dev;
  53         bool is_read;
  54         int ret;
  55
  56         /* Special test code to return success but with no emulation */
  57         if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR)
  58                 return 0;
  59
  60         ret = i2c_get_chip(bus, msg->addr, 1, &dev);
  61         if (ret)
  62                 return ret;
  63
  64         ret = get_emul(dev, &emul, &ops);
  65         if (ret)
  66                 return ret;
  67
  68         if (priv->test_mode) {
  69                 /*
  70                 * For testing, don't allow writing above 100KHz for writes and
  71                 * 400KHz for reads.
  72                 */
  73                 is_read = nmsgs > 1;
  74                 if (i2c->speed_hz > (is_read ? I2C_SPEED_FAST_RATE :
  75                                 I2C_SPEED_STANDARD_RATE)) {
  76                         debug("%s: Max speed exceeded\n", __func__);
  77                         return -EINVAL;
  78                 }
  79         }
  80
  81         return ops->xfer(emul, msg, nmsgs);
  82 }
  83
  84 static const struct dm_i2c_ops sandbox_i2c_ops = {
  85         .xfer           = sandbox_i2c_xfer,
  86 };
  87
  88 static const struct udevice_id sandbox_i2c_ids[] = {
  89         { .compatible = "sandbox,i2c" },
  90         { }
  91 };
  92
  93 U_BOOT_DRIVER(sandbox_i2c) = {
  94         .name   = "sandbox_i2c",
  95         .id     = UCLASS_I2C,
  96         .of_match = sandbox_i2c_ids,
  97         .ops    = &sandbox_i2c_ops,
  98         .priv_auto      = sizeof(struct sandbox_i2c_priv),
  99 };