1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (c) 2015 Google, Inc 4 * Written by Simon Glass <sjg@chromium.org> 5 */ 6 7 #include <common.h> 8 #include <dm.h> 9 #include <errno.h> 10 #include <i2c.h> 11 #include <dm/lists.h> 12 #include <dm/root.h> 13 14 /** 15 * struct i2c_mux: Information the uclass stores about an I2C mux 16 * 17 * @selected: Currently selected mux, or -1 for none 18 * @i2c_bus: I2C bus to use for communcation 19 */ 20 struct i2c_mux { 21 int selected; 22 struct udevice *i2c_bus; 23 }; 24 25 /** 26 * struct i2c_mux_bus: Information about each bus the mux controls 27 * 28 * @channel: Channel number used to select this bus 29 */ 30 struct i2c_mux_bus { 31 uint channel; 32 }; 33 34 /* Find out the mux channel number */ 35 static int i2c_mux_child_post_bind(struct udevice *dev) 36 { 37 struct i2c_mux_bus *plat = dev_get_parent_platdata(dev); 38 int channel; 39 40 channel = dev_read_u32_default(dev, "reg", -1); 41 if (channel < 0) 42 return -EINVAL; 43 plat->channel = channel; 44 45 return 0; 46 } 47 48 /* Find the I2C buses selected by this mux */ 49 static int i2c_mux_post_bind(struct udevice *mux) 50 { 51 ofnode node; 52 int ret; 53 54 debug("%s: %s\n", __func__, mux->name); 55 /* 56 * There is no compatible string in the sub-nodes, so we must manually 57 * bind these 58 */ 59 dev_for_each_subnode(node, mux) { 60 struct udevice *dev; 61 const char *name; 62 63 name = ofnode_get_name(node); 64 ret = device_bind_driver_to_node(mux, "i2c_mux_bus_drv", name, 65 node, &dev); 66 debug(" - bind ret=%d, %s\n", ret, dev ? dev->name : NULL); 67 if (ret) 68 return ret; 69 } 70 71 return 0; 72 } 73 74 /* Set up the mux ready for use */ 75 static int i2c_mux_post_probe(struct udevice *mux) 76 { 77 struct i2c_mux *priv = dev_get_uclass_priv(mux); 78 int ret; 79 80 debug("%s: %s\n", __func__, mux->name); 81 priv->selected = -1; 82 83 /* if parent is of i2c uclass already, we'll take that, otherwise 84 * look if we find an i2c-parent phandle 85 */ 86 if (UCLASS_I2C == device_get_uclass_id(mux->parent)) { 87 priv->i2c_bus = dev_get_parent(mux); 88 debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus, 89 priv->i2c_bus->name); 90 return 0; 91 } 92 93 ret = uclass_get_device_by_phandle(UCLASS_I2C, mux, "i2c-parent", 94 &priv->i2c_bus); 95 if (ret) 96 return ret; 97 debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus, priv->i2c_bus->name); 98 99 return 0; 100 } 101 102 int i2c_mux_select(struct udevice *dev) 103 { 104 struct i2c_mux_bus *plat = dev_get_parent_platdata(dev); 105 struct udevice *mux = dev->parent; 106 struct i2c_mux_ops *ops = i2c_mux_get_ops(mux); 107 108 if (!ops->select) 109 return -ENOSYS; 110 111 return ops->select(mux, dev, plat->channel); 112 } 113 114 int i2c_mux_deselect(struct udevice *dev) 115 { 116 struct i2c_mux_bus *plat = dev_get_parent_platdata(dev); 117 struct udevice *mux = dev->parent; 118 struct i2c_mux_ops *ops = i2c_mux_get_ops(mux); 119 120 if (!ops->deselect) 121 return -ENOSYS; 122 123 return ops->deselect(mux, dev, plat->channel); 124 } 125 126 static int i2c_mux_bus_set_bus_speed(struct udevice *dev, unsigned int speed) 127 { 128 struct udevice *mux = dev->parent; 129 struct i2c_mux *priv = dev_get_uclass_priv(mux); 130 int ret, ret2; 131 132 ret = i2c_mux_select(dev); 133 if (ret) 134 return ret; 135 ret = dm_i2c_set_bus_speed(priv->i2c_bus, speed); 136 ret2 = i2c_mux_deselect(dev); 137 138 return ret ? ret : ret2; 139 } 140 141 static int i2c_mux_bus_probe(struct udevice *dev, uint chip_addr, 142 uint chip_flags) 143 { 144 struct udevice *mux = dev->parent; 145 struct i2c_mux *priv = dev_get_uclass_priv(mux); 146 struct dm_i2c_ops *ops = i2c_get_ops(priv->i2c_bus); 147 int ret, ret2; 148 149 debug("%s: %s, bus %s\n", __func__, dev->name, priv->i2c_bus->name); 150 if (!ops->probe_chip) 151 return -ENOSYS; 152 ret = i2c_mux_select(dev); 153 if (ret) 154 return ret; 155 ret = ops->probe_chip(priv->i2c_bus, chip_addr, chip_flags); 156 ret2 = i2c_mux_deselect(dev); 157 158 return ret ? ret : ret2; 159 } 160 161 static int i2c_mux_bus_xfer(struct udevice *dev, struct i2c_msg *msg, 162 int nmsgs) 163 { 164 struct udevice *mux = dev->parent; 165 struct i2c_mux *priv = dev_get_uclass_priv(mux); 166 struct dm_i2c_ops *ops = i2c_get_ops(priv->i2c_bus); 167 int ret, ret2; 168 169 debug("%s: %s, bus %s\n", __func__, dev->name, priv->i2c_bus->name); 170 if (!ops->xfer) 171 return -ENOSYS; 172 ret = i2c_mux_select(dev); 173 if (ret) 174 return ret; 175 ret = ops->xfer(priv->i2c_bus, msg, nmsgs); 176 ret2 = i2c_mux_deselect(dev); 177 178 return ret ? ret : ret2; 179 } 180 181 static const struct dm_i2c_ops i2c_mux_bus_ops = { 182 .xfer = i2c_mux_bus_xfer, 183 .probe_chip = i2c_mux_bus_probe, 184 .set_bus_speed = i2c_mux_bus_set_bus_speed, 185 }; 186 187 U_BOOT_DRIVER(i2c_mux_bus) = { 188 .name = "i2c_mux_bus_drv", 189 .id = UCLASS_I2C, 190 .ops = &i2c_mux_bus_ops, 191 }; 192 193 UCLASS_DRIVER(i2c_mux) = { 194 .id = UCLASS_I2C_MUX, 195 .name = "i2c_mux", 196 .post_bind = i2c_mux_post_bind, 197 .post_probe = i2c_mux_post_probe, 198 .per_device_auto_alloc_size = sizeof(struct i2c_mux), 199 .per_child_platdata_auto_alloc_size = sizeof(struct i2c_mux_bus), 200 .child_post_bind = i2c_mux_child_post_bind, 201 }; 202