1 /* 2 * Simulate an I2C port 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 <asm/test.h> 14 #include <dm/lists.h> 15 #include <dm/device-internal.h> 16 17 DECLARE_GLOBAL_DATA_PTR; 18 19 struct sandbox_i2c_priv { 20 bool test_mode; 21 }; 22 23 static int get_emul(struct udevice *dev, struct udevice **devp, 24 struct dm_i2c_ops **opsp) 25 { 26 struct dm_i2c_chip *plat; 27 struct udevice *child; 28 int ret; 29 30 *devp = NULL; 31 *opsp = NULL; 32 plat = dev_get_parent_platdata(dev); 33 if (!plat->emul) { 34 ret = dm_scan_fdt_dev(dev); 35 if (ret) 36 return ret; 37 38 for (device_find_first_child(dev, &child); child; 39 device_find_next_child(&child)) { 40 if (device_get_uclass_id(child) != UCLASS_I2C_EMUL) 41 continue; 42 43 ret = device_probe(child); 44 if (ret) 45 return ret; 46 47 break; 48 } 49 50 if (child) 51 plat->emul = child; 52 else 53 return -ENODEV; 54 } 55 *devp = plat->emul; 56 *opsp = i2c_get_ops(plat->emul); 57 58 return 0; 59 } 60 61 void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode) 62 { 63 struct sandbox_i2c_priv *priv = dev_get_priv(bus); 64 65 priv->test_mode = test_mode; 66 } 67 68 static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, 69 int nmsgs) 70 { 71 struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus); 72 struct sandbox_i2c_priv *priv = dev_get_priv(bus); 73 struct dm_i2c_ops *ops; 74 struct udevice *emul, *dev; 75 bool is_read; 76 int ret; 77 78 /* Special test code to return success but with no emulation */ 79 if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR) 80 return 0; 81 82 ret = i2c_get_chip(bus, msg->addr, 1, &dev); 83 if (ret) 84 return ret; 85 86 ret = get_emul(dev, &emul, &ops); 87 if (ret) 88 return ret; 89 90 if (priv->test_mode) { 91 /* 92 * For testing, don't allow writing above 100KHz for writes and 93 * 400KHz for reads. 94 */ 95 is_read = nmsgs > 1; 96 if (i2c->speed_hz > (is_read ? 400000 : 100000)) { 97 debug("%s: Max speed exceeded\n", __func__); 98 return -EINVAL; 99 } 100 } 101 102 return ops->xfer(emul, msg, nmsgs); 103 } 104 105 static const struct dm_i2c_ops sandbox_i2c_ops = { 106 .xfer = sandbox_i2c_xfer, 107 }; 108 109 static const struct udevice_id sandbox_i2c_ids[] = { 110 { .compatible = "sandbox,i2c" }, 111 { } 112 }; 113 114 U_BOOT_DRIVER(i2c_sandbox) = { 115 .name = "i2c_sandbox", 116 .id = UCLASS_I2C, 117 .of_match = sandbox_i2c_ids, 118 .ops = &sandbox_i2c_ops, 119 .priv_auto_alloc_size = sizeof(struct sandbox_i2c_priv), 120 }; 121