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