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 const char *arrow = "->"; 63 char *full_name; 64 int parent_name_len, arrow_len, mux_name_len, name_len; 65 66 name = ofnode_get_name(node); 67 68 /* Calculate lenghts of strings */ 69 parent_name_len = strlen(mux->parent->name); 70 arrow_len = strlen(arrow); 71 mux_name_len = strlen(mux->name); 72 name_len = strlen(name); 73 74 full_name = calloc(1, parent_name_len + arrow_len + 75 mux_name_len + arrow_len + name_len + 1); 76 if (!full_name) 77 return -ENOMEM; 78 79 /* Compose bus name */ 80 strcat(full_name, mux->parent->name); 81 strcat(full_name, arrow); 82 strcat(full_name, mux->name); 83 strcat(full_name, arrow); 84 strcat(full_name, name); 85 86 ret = device_bind_driver_to_node(mux, "i2c_mux_bus_drv", 87 full_name, node, &dev); 88 debug(" - bind ret=%d, %s, req_seq %d\n", ret, 89 dev ? dev->name : NULL, dev->req_seq); 90 if (ret) 91 return ret; 92 } 93 94 return 0; 95 } 96 97 /* Set up the mux ready for use */ 98 static int i2c_mux_post_probe(struct udevice *mux) 99 { 100 struct i2c_mux *priv = dev_get_uclass_priv(mux); 101 int ret; 102 103 debug("%s: %s\n", __func__, mux->name); 104 priv->selected = -1; 105 106 /* if parent is of i2c uclass already, we'll take that, otherwise 107 * look if we find an i2c-parent phandle 108 */ 109 if (UCLASS_I2C == device_get_uclass_id(mux->parent)) { 110 priv->i2c_bus = dev_get_parent(mux); 111 debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus, 112 priv->i2c_bus->name); 113 return 0; 114 } 115 116 ret = uclass_get_device_by_phandle(UCLASS_I2C, mux, "i2c-parent", 117 &priv->i2c_bus); 118 if (ret) 119 return ret; 120 debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus, priv->i2c_bus->name); 121 122 return 0; 123 } 124 125 int i2c_mux_select(struct udevice *dev) 126 { 127 struct i2c_mux_bus *plat = dev_get_parent_platdata(dev); 128 struct udevice *mux = dev->parent; 129 struct i2c_mux_ops *ops = i2c_mux_get_ops(mux); 130 131 if (!ops->select) 132 return -ENOSYS; 133 134 return ops->select(mux, dev, plat->channel); 135 } 136 137 int i2c_mux_deselect(struct udevice *dev) 138 { 139 struct i2c_mux_bus *plat = dev_get_parent_platdata(dev); 140 struct udevice *mux = dev->parent; 141 struct i2c_mux_ops *ops = i2c_mux_get_ops(mux); 142 143 if (!ops->deselect) 144 return -ENOSYS; 145 146 return ops->deselect(mux, dev, plat->channel); 147 } 148 149 static int i2c_mux_bus_set_bus_speed(struct udevice *dev, unsigned int speed) 150 { 151 struct udevice *mux = dev->parent; 152 struct i2c_mux *priv = dev_get_uclass_priv(mux); 153 int ret, ret2; 154 155 ret = i2c_mux_select(dev); 156 if (ret) 157 return ret; 158 ret = dm_i2c_set_bus_speed(priv->i2c_bus, speed); 159 ret2 = i2c_mux_deselect(dev); 160 161 return ret ? ret : ret2; 162 } 163 164 static int i2c_mux_bus_probe(struct udevice *dev, uint chip_addr, 165 uint chip_flags) 166 { 167 struct udevice *mux = dev->parent; 168 struct i2c_mux *priv = dev_get_uclass_priv(mux); 169 struct dm_i2c_ops *ops = i2c_get_ops(priv->i2c_bus); 170 int ret, ret2; 171 172 debug("%s: %s, bus %s\n", __func__, dev->name, priv->i2c_bus->name); 173 if (!ops->probe_chip) 174 return -ENOSYS; 175 ret = i2c_mux_select(dev); 176 if (ret) 177 return ret; 178 ret = ops->probe_chip(priv->i2c_bus, chip_addr, chip_flags); 179 ret2 = i2c_mux_deselect(dev); 180 181 return ret ? ret : ret2; 182 } 183 184 static int i2c_mux_bus_xfer(struct udevice *dev, struct i2c_msg *msg, 185 int nmsgs) 186 { 187 struct udevice *mux = dev->parent; 188 struct i2c_mux *priv = dev_get_uclass_priv(mux); 189 struct dm_i2c_ops *ops = i2c_get_ops(priv->i2c_bus); 190 int ret, ret2; 191 192 debug("%s: %s, bus %s\n", __func__, dev->name, priv->i2c_bus->name); 193 if (!ops->xfer) 194 return -ENOSYS; 195 ret = i2c_mux_select(dev); 196 if (ret) 197 return ret; 198 ret = ops->xfer(priv->i2c_bus, msg, nmsgs); 199 ret2 = i2c_mux_deselect(dev); 200 201 return ret ? ret : ret2; 202 } 203 204 static const struct dm_i2c_ops i2c_mux_bus_ops = { 205 .xfer = i2c_mux_bus_xfer, 206 .probe_chip = i2c_mux_bus_probe, 207 .set_bus_speed = i2c_mux_bus_set_bus_speed, 208 }; 209 210 U_BOOT_DRIVER(i2c_mux_bus) = { 211 .name = "i2c_mux_bus_drv", 212 .id = UCLASS_I2C, 213 .ops = &i2c_mux_bus_ops, 214 }; 215 216 UCLASS_DRIVER(i2c_mux) = { 217 .id = UCLASS_I2C_MUX, 218 .name = "i2c_mux", 219 .post_bind = i2c_mux_post_bind, 220 .post_probe = i2c_mux_post_probe, 221 .per_device_auto_alloc_size = sizeof(struct i2c_mux), 222 .per_child_platdata_auto_alloc_size = sizeof(struct i2c_mux_bus), 223 .child_post_bind = i2c_mux_child_post_bind, 224 }; 225