git.sur5r.net Git - u-boot/blob - 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 <asm/test.h>
  13 #include <dm/lists.h>
  14 #include <dm/device-internal.h>
  15
  16 struct sandbox_i2c_priv {
  17         bool test_mode;
  18 };
  19
  20 static int get_emul(struct udevice *dev, struct udevice **devp,
  21                     struct dm_i2c_ops **opsp)
  22 {
  23         struct dm_i2c_chip *plat;
  24         struct udevice *child;
  25         int ret;
  26
  27         *devp = NULL;
  28         *opsp = NULL;
  29         plat = dev_get_parent_platdata(dev);
  30         if (!plat->emul) {
  31                 ret = dm_scan_fdt_dev(dev);
  32                 if (ret)
  33                         return ret;
  34
  35                 for (device_find_first_child(dev, &child); child;
  36                      device_find_next_child(&child)) {
  37                         if (device_get_uclass_id(child) != UCLASS_I2C_EMUL)
  38                                 continue;
  39
  40                         ret = device_probe(child);
  41                         if (ret)
  42                                 return ret;
  43
  44                         break;
  45                 }
  46
  47                 if (child)
  48                         plat->emul = child;
  49                 else
  50                         return -ENODEV;
  51         }
  52         *devp = plat->emul;
  53         *opsp = i2c_get_ops(plat->emul);
  54
  55         return 0;
  56 }
  57
  58 void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode)
  59 {
  60         struct sandbox_i2c_priv *priv = dev_get_priv(bus);
  61
  62         priv->test_mode = test_mode;
  63 }
  64
  65 static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
  66                             int nmsgs)
  67 {
  68         struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus);
  69         struct sandbox_i2c_priv *priv = dev_get_priv(bus);
  70         struct dm_i2c_ops *ops;
  71         struct udevice *emul, *dev;
  72         bool is_read;
  73         int ret;
  74
  75         /* Special test code to return success but with no emulation */
  76         if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR)
  77                 return 0;
  78
  79         ret = i2c_get_chip(bus, msg->addr, 1, &dev);
  80         if (ret)
  81                 return ret;
  82
  83         ret = get_emul(dev, &emul, &ops);
  84         if (ret)
  85                 return ret;
  86
  87         if (priv->test_mode) {
  88                 /*
  89                 * For testing, don't allow writing above 100KHz for writes and
  90                 * 400KHz for reads.
  91                 */
  92                 is_read = nmsgs > 1;
  93                 if (i2c->speed_hz > (is_read ? 400000 : 100000)) {
  94                         debug("%s: Max speed exceeded\n", __func__);
  95                         return -EINVAL;
  96                 }
  97         }
  98
  99         return ops->xfer(emul, msg, nmsgs);
 100 }
 101
 102 static const struct dm_i2c_ops sandbox_i2c_ops = {
 103         .xfer           = sandbox_i2c_xfer,
 104 };
 105
 106 static const struct udevice_id sandbox_i2c_ids[] = {
 107         { .compatible = "sandbox,i2c" },
 108         { }
 109 };
 110
 111 U_BOOT_DRIVER(i2c_sandbox) = {
 112         .name   = "i2c_sandbox",
 113         .id     = UCLASS_I2C,
 114         .of_match = sandbox_i2c_ids,
 115         .ops    = &sandbox_i2c_ops,
 116         .priv_auto_alloc_size = sizeof(struct sandbox_i2c_priv),
 117 };