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 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_node(dev, gd->fdt_blob, dev->of_offset, 36 false); 37 if (ret) 38 return ret; 39 40 ret = device_get_child(dev, 0, &plat->emul); 41 if (ret) 42 return ret; 43 } 44 *devp = plat->emul; 45 *opsp = i2c_get_ops(plat->emul); 46 47 return 0; 48 } 49 50 void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode) 51 { 52 struct sandbox_i2c_priv *priv = dev_get_priv(bus); 53 54 priv->test_mode = test_mode; 55 } 56 57 static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, 58 int nmsgs) 59 { 60 struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus); 61 struct sandbox_i2c_priv *priv = dev_get_priv(bus); 62 struct dm_i2c_ops *ops; 63 struct udevice *emul, *dev; 64 bool is_read; 65 int ret; 66 67 /* Special test code to return success but with no emulation */ 68 if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR) 69 return 0; 70 71 ret = i2c_get_chip(bus, msg->addr, 1, &dev); 72 if (ret) 73 return ret; 74 75 ret = get_emul(dev, &emul, &ops); 76 if (ret) 77 return ret; 78 79 if (priv->test_mode) { 80 /* 81 * For testing, don't allow writing above 100KHz for writes and 82 * 400KHz for reads. 83 */ 84 is_read = nmsgs > 1; 85 if (i2c->speed_hz > (is_read ? 400000 : 100000)) { 86 debug("%s: Max speed exceeded\n", __func__); 87 return -EINVAL; 88 } 89 } 90 91 return ops->xfer(emul, msg, nmsgs); 92 } 93 94 static const struct dm_i2c_ops sandbox_i2c_ops = { 95 .xfer = sandbox_i2c_xfer, 96 }; 97 98 static const struct udevice_id sandbox_i2c_ids[] = { 99 { .compatible = "sandbox,i2c" }, 100 { } 101 }; 102 103 U_BOOT_DRIVER(i2c_sandbox) = { 104 .name = "i2c_sandbox", 105 .id = UCLASS_I2C, 106 .of_match = sandbox_i2c_ids, 107 .ops = &sandbox_i2c_ops, 108 .priv_auto_alloc_size = sizeof(struct sandbox_i2c_priv), 109 }; 110