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 int ret; 25 26 *devp = NULL; 27 *opsp = NULL; 28 plat = dev_get_parent_platdata(dev); 29 if (!plat->emul) { 30 ret = i2c_emul_find(dev, &plat->emul); 31 if (ret) 32 return ret; 33 } 34 *devp = plat->emul; 35 *opsp = i2c_get_ops(plat->emul); 36 37 return 0; 38 } 39 40 void sandbox_i2c_set_test_mode(struct udevice *bus, bool test_mode) 41 { 42 struct sandbox_i2c_priv *priv = dev_get_priv(bus); 43 44 priv->test_mode = test_mode; 45 } 46 47 static int sandbox_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, 48 int nmsgs) 49 { 50 struct dm_i2c_bus *i2c = dev_get_uclass_priv(bus); 51 struct sandbox_i2c_priv *priv = dev_get_priv(bus); 52 struct dm_i2c_ops *ops; 53 struct udevice *emul, *dev; 54 bool is_read; 55 int ret; 56 57 /* Special test code to return success but with no emulation */ 58 if (priv->test_mode && msg->addr == SANDBOX_I2C_TEST_ADDR) 59 return 0; 60 61 ret = i2c_get_chip(bus, msg->addr, 1, &dev); 62 if (ret) 63 return ret; 64 65 ret = get_emul(dev, &emul, &ops); 66 if (ret) 67 return ret; 68 69 if (priv->test_mode) { 70 /* 71 * For testing, don't allow writing above 100KHz for writes and 72 * 400KHz for reads. 73 */ 74 is_read = nmsgs > 1; 75 if (i2c->speed_hz > (is_read ? 400000 : 100000)) { 76 debug("%s: Max speed exceeded\n", __func__); 77 return -EINVAL; 78 } 79 } 80 81 return ops->xfer(emul, msg, nmsgs); 82 } 83 84 static const struct dm_i2c_ops sandbox_i2c_ops = { 85 .xfer = sandbox_i2c_xfer, 86 }; 87 88 static const struct udevice_id sandbox_i2c_ids[] = { 89 { .compatible = "sandbox,i2c" }, 90 { } 91 }; 92 93 U_BOOT_DRIVER(i2c_sandbox) = { 94 .name = "i2c_sandbox", 95 .id = UCLASS_I2C, 96 .of_match = sandbox_i2c_ids, 97 .ops = &sandbox_i2c_ops, 98 .priv_auto_alloc_size = sizeof(struct sandbox_i2c_priv), 99 }; 100