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 <fdtdec.h> 13 #include <i2c.h> 14 #include <asm/test.h> 15 #include <dm/lists.h> 16 #include <dm/device-internal.h> 17 #include <dm/root.h> 18 19 DECLARE_GLOBAL_DATA_PTR; 20 21 struct sandbox_i2c_priv { 22 bool test_mode; 23 }; 24 25 static int get_emul(struct udevice *dev, struct udevice **devp, 26 struct dm_i2c_ops **opsp) 27 { 28 struct dm_i2c_chip *plat; 29 struct udevice *child; 30 int ret; 31 32 *devp = NULL; 33 *opsp = NULL; 34 plat = dev_get_parent_platdata(dev); 35 if (!plat->emul) { 36 ret = dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, 37 false); 38 if (ret) 39 return ret; 40 41 for (device_find_first_child(dev, &child); child; 42 device_find_next_child(&child)) { 43 if (device_get_uclass_id(child) != UCLASS_I2C_EMUL) 44 continue; 45 46 ret = device_probe(child); 47 if (ret) 48 return ret; 49 50 break; 51 } 52 53 if (child) 54 plat->emul = child; 55 else 56 return -ENODEV; 57 } 58 *devp = plat->emul; 59 *opsp = i2c_get_ops(plat->emul); 60 61 return 0; 62 } 63 64 void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode) 65 { 66 struct sandbox_i2c_priv *priv = dev_get_priv(bus); 67 68 priv->test_mode = test_mode; 69 } 70 71 static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, 72 int nmsgs) 73 { 74 struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus); 75 struct sandbox_i2c_priv *priv = dev_get_priv(bus); 76 struct dm_i2c_ops *ops; 77 struct udevice *emul, *dev; 78 bool is_read; 79 int ret; 80 81 /* Special test code to return success but with no emulation */ 82 if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR) 83 return 0; 84 85 ret = i2c_get_chip(bus, msg->addr, 1, &dev); 86 if (ret) 87 return ret; 88 89 ret = get_emul(dev, &emul, &ops); 90 if (ret) 91 return ret; 92 93 if (priv->test_mode) { 94 /* 95 * For testing, don't allow writing above 100KHz for writes and 96 * 400KHz for reads. 97 */ 98 is_read = nmsgs > 1; 99 if (i2c->speed_hz > (is_read ? 400000 : 100000)) { 100 debug("%s: Max speed exceeded\n", __func__); 101 return -EINVAL; 102 } 103 } 104 105 return ops->xfer(emul, msg, nmsgs); 106 } 107 108 static const struct dm_i2c_ops sandbox_i2c_ops = { 109 .xfer = sandbox_i2c_xfer, 110 }; 111 112 static const struct udevice_id sandbox_i2c_ids[] = { 113 { .compatible = "sandbox,i2c" }, 114 { } 115 }; 116 117 U_BOOT_DRIVER(i2c_sandbox) = { 118 .name = "i2c_sandbox", 119 .id = UCLASS_I2C, 120 .of_match = sandbox_i2c_ids, 121 .ops = &sandbox_i2c_ops, 122 .priv_auto_alloc_size = sizeof(struct sandbox_i2c_priv), 123 }; 124