1 /* 2 * Copyright (c) 2015 Google, Inc 3 * Written by Simon Glass <sjg@chromium.org> 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 #include <common.h> 9 #include <dm.h> 10 #include <errno.h> 11 #include <i2c.h> 12 #include <dm/lists.h> 13 #include <dm/root.h> 14 15 DECLARE_GLOBAL_DATA_PTR; 16 17 /** 18 * struct i2c_mux: Information the uclass stores about an I2C mux 19 * 20 * @selected: Currently selected mux, or -1 for none 21 * @i2c_bus: I2C bus to use for communcation 22 */ 23 struct i2c_mux { 24 int selected; 25 struct udevice *i2c_bus; 26 }; 27 28 /** 29 * struct i2c_mux_bus: Information about each bus the mux controls 30 * 31 * @channel: Channel number used to select this bus 32 */ 33 struct i2c_mux_bus { 34 uint channel; 35 }; 36 37 /* Find out the mux channel number */ 38 static int i2c_mux_child_post_bind(struct udevice *dev) 39 { 40 struct i2c_mux_bus *plat = dev_get_parent_platdata(dev); 41 int channel; 42 43 channel = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev), "reg", -1); 44 if (channel < 0) 45 return -EINVAL; 46 plat->channel = channel; 47 48 return 0; 49 } 50 51 /* Find the I2C buses selected by this mux */ 52 static int i2c_mux_post_bind(struct udevice *mux) 53 { 54 ofnode node; 55 int ret; 56 57 debug("%s: %s\n", __func__, mux->name); 58 /* 59 * There is no compatible string in the sub-nodes, so we must manually 60 * bind these 61 */ 62 dev_for_each_subnode(node, mux) { 63 struct udevice *dev; 64 const char *name; 65 66 name = ofnode_get_name(node); 67 ret = device_bind_driver_to_node(mux, "i2c_mux_bus_drv", name, 68 node, &dev); 69 debug(" - bind ret=%d, %s\n", ret, dev ? dev->name : NULL); 70 if (ret) 71 return ret; 72 } 73 74 return 0; 75 } 76 77 /* Set up the mux ready for use */ 78 static int i2c_mux_post_probe(struct udevice *mux) 79 { 80 struct i2c_mux *priv = dev_get_uclass_priv(mux); 81 int ret; 82 83 debug("%s: %s\n", __func__, mux->name); 84 priv->selected = -1; 85 86 /* if parent is of i2c uclass already, we'll take that, otherwise 87 * look if we find an i2c-parent phandle 88 */ 89 if (UCLASS_I2C == device_get_uclass_id(mux->parent)) { 90 priv->i2c_bus = dev_get_parent(mux); 91 debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus, 92 priv->i2c_bus->name); 93 return 0; 94 } 95 96 ret = uclass_get_device_by_phandle(UCLASS_I2C, mux, "i2c-parent", 97 &priv->i2c_bus); 98 if (ret) 99 return ret; 100 debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus, priv->i2c_bus->name); 101 102 return 0; 103 } 104 105 int i2c_mux_select(struct udevice *dev) 106 { 107 struct i2c_mux_bus *plat = dev_get_parent_platdata(dev); 108 struct udevice *mux = dev->parent; 109 struct i2c_mux_ops *ops = i2c_mux_get_ops(mux); 110 111 if (!ops->select) 112 return -ENOSYS; 113 114 return ops->select(mux, dev, plat->channel); 115 } 116 117 int i2c_mux_deselect(struct udevice *dev) 118 { 119 struct i2c_mux_bus *plat = dev_get_parent_platdata(dev); 120 struct udevice *mux = dev->parent; 121 struct i2c_mux_ops *ops = i2c_mux_get_ops(mux); 122 123 if (!ops->deselect) 124 return -ENOSYS; 125 126 return ops->deselect(mux, dev, plat->channel); 127 } 128 129 static int i2c_mux_bus_set_bus_speed(struct udevice *dev, unsigned int speed) 130 { 131 struct udevice *mux = dev->parent; 132 struct i2c_mux *priv = dev_get_uclass_priv(mux); 133 int ret, ret2; 134 135 ret = i2c_mux_select(dev); 136 if (ret) 137 return ret; 138 ret = dm_i2c_set_bus_speed(priv->i2c_bus, speed); 139 ret2 = i2c_mux_deselect(dev); 140 141 return ret ? ret : ret2; 142 } 143 144 static int i2c_mux_bus_probe(struct udevice *dev, uint chip_addr, 145 uint chip_flags) 146 { 147 struct udevice *mux = dev->parent; 148 struct i2c_mux *priv = dev_get_uclass_priv(mux); 149 struct dm_i2c_ops *ops = i2c_get_ops(priv->i2c_bus); 150 int ret, ret2; 151 152 debug("%s: %s, bus %s\n", __func__, dev->name, priv->i2c_bus->name); 153 if (!ops->probe_chip) 154 return -ENOSYS; 155 ret = i2c_mux_select(dev); 156 if (ret) 157 return ret; 158 ret = ops->probe_chip(priv->i2c_bus, chip_addr, chip_flags); 159 ret2 = i2c_mux_deselect(dev); 160 161 return ret ? ret : ret2; 162 } 163 164 static int i2c_mux_bus_xfer(struct udevice *dev, struct i2c_msg *msg, 165 int nmsgs) 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->xfer) 174 return -ENOSYS; 175 ret = i2c_mux_select(dev); 176 if (ret) 177 return ret; 178 ret = ops->xfer(priv->i2c_bus, msg, nmsgs); 179 ret2 = i2c_mux_deselect(dev); 180 181 return ret ? ret : ret2; 182 } 183 184 static const struct dm_i2c_ops i2c_mux_bus_ops = { 185 .xfer = i2c_mux_bus_xfer, 186 .probe_chip = i2c_mux_bus_probe, 187 .set_bus_speed = i2c_mux_bus_set_bus_speed, 188 }; 189 190 U_BOOT_DRIVER(i2c_mux_bus) = { 191 .name = "i2c_mux_bus_drv", 192 .id = UCLASS_I2C, 193 .ops = &i2c_mux_bus_ops, 194 }; 195 196 UCLASS_DRIVER(i2c_mux) = { 197 .id = UCLASS_I2C_MUX, 198 .name = "i2c_mux", 199 .post_bind = i2c_mux_post_bind, 200 .post_probe = i2c_mux_post_probe, 201 .per_device_auto_alloc_size = sizeof(struct i2c_mux), 202 .per_child_platdata_auto_alloc_size = sizeof(struct i2c_mux_bus), 203 .child_post_bind = i2c_mux_child_post_bind, 204 }; 205