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 }; 118
