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, "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 const void *blob = gd->fdt_blob; 55 int ret; 56 int offset; 57 58 debug("%s: %s\n", __func__, mux->name); 59 /* 60 * There is no compatible string in the sub-nodes, so we must manually 61 * bind these 62 */ 63 for (offset = fdt_first_subnode(blob, mux->of_offset); 64 offset > 0; 65 offset = fdt_next_subnode(blob, offset)) { 66 struct udevice *dev; 67 const char *name; 68 69 name = fdt_get_name(blob, offset, NULL); 70 ret = device_bind_driver_to_node(mux, "i2c_mux_bus_drv", name, 71 offset, &dev); 72 debug(" - bind ret=%d, %s\n", ret, dev ? dev->name : NULL); 73 if (ret) 74 return ret; 75 } 76 77 return 0; 78 } 79 80 /* Set up the mux ready for use */ 81 static int i2c_mux_post_probe(struct udevice *mux) 82 { 83 struct i2c_mux *priv = dev_get_uclass_priv(mux); 84 int ret; 85 86 debug("%s: %s\n", __func__, mux->name); 87 priv->selected = -1; 88 89 /* if parent is of i2c uclass already, we'll take that, otherwise 90 * look if we find an i2c-parent phandle 91 */ 92 if (UCLASS_I2C == device_get_uclass_id(mux->parent)) { 93 priv->i2c_bus = dev_get_parent(mux); 94 debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus, 95 priv->i2c_bus->name); 96 return 0; 97 } 98 99 ret = uclass_get_device_by_phandle(UCLASS_I2C, mux, "i2c-parent", 100 &priv->i2c_bus); 101 if (ret) 102 return ret; 103 debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus, priv->i2c_bus->name); 104 105 return 0; 106 } 107 108 int i2c_mux_select(struct udevice *dev) 109 { 110 struct i2c_mux_bus *plat = dev_get_parent_platdata(dev); 111 struct udevice *mux = dev->parent; 112 struct i2c_mux_ops *ops = i2c_mux_get_ops(mux); 113 114 if (!ops->select) 115 return -ENOSYS; 116 117 return ops->select(mux, dev, plat->channel); 118 } 119 120 int i2c_mux_deselect(struct udevice *dev) 121 { 122 struct i2c_mux_bus *plat = dev_get_parent_platdata(dev); 123 struct udevice *mux = dev->parent; 124 struct i2c_mux_ops *ops = i2c_mux_get_ops(mux); 125 126 if (!ops->deselect) 127 return -ENOSYS; 128 129 return ops->deselect(mux, dev, plat->channel); 130 } 131 132 static int i2c_mux_bus_set_bus_speed(struct udevice *dev, unsigned int speed) 133 { 134 struct udevice *mux = dev->parent; 135 struct i2c_mux *priv = dev_get_uclass_priv(mux); 136 int ret, ret2; 137 138 ret = i2c_mux_select(dev); 139 if (ret) 140 return ret; 141 ret = dm_i2c_set_bus_speed(priv->i2c_bus, speed); 142 ret2 = i2c_mux_deselect(dev); 143 144 return ret ? ret : ret2; 145 } 146 147 static int i2c_mux_bus_probe(struct udevice *dev, uint chip_addr, 148 uint chip_flags) 149 { 150 struct udevice *mux = dev->parent; 151 struct i2c_mux *priv = dev_get_uclass_priv(mux); 152 struct dm_i2c_ops *ops = i2c_get_ops(priv->i2c_bus); 153 int ret, ret2; 154 155 debug("%s: %s, bus %s\n", __func__, dev->name, priv->i2c_bus->name); 156 if (!ops->probe_chip) 157 return -ENOSYS; 158 ret = i2c_mux_select(dev); 159 if (ret) 160 return ret; 161 ret = ops->probe_chip(priv->i2c_bus, chip_addr, chip_flags); 162 ret2 = i2c_mux_deselect(dev); 163 164 return ret ? ret : ret2; 165 } 166 167 static int i2c_mux_bus_xfer(struct udevice *dev, struct i2c_msg *msg, 168 int nmsgs) 169 { 170 struct udevice *mux = dev->parent; 171 struct i2c_mux *priv = dev_get_uclass_priv(mux); 172 struct dm_i2c_ops *ops = i2c_get_ops(priv->i2c_bus); 173 int ret, ret2; 174 175 debug("%s: %s, bus %s\n", __func__, dev->name, priv->i2c_bus->name); 176 if (!ops->xfer) 177 return -ENOSYS; 178 ret = i2c_mux_select(dev); 179 if (ret) 180 return ret; 181 ret = ops->xfer(priv->i2c_bus, msg, nmsgs); 182 ret2 = i2c_mux_deselect(dev); 183 184 return ret ? ret : ret2; 185 } 186 187 static const struct dm_i2c_ops i2c_mux_bus_ops = { 188 .xfer = i2c_mux_bus_xfer, 189 .probe_chip = i2c_mux_bus_probe, 190 .set_bus_speed = i2c_mux_bus_set_bus_speed, 191 }; 192 193 U_BOOT_DRIVER(i2c_mux_bus) = { 194 .name = "i2c_mux_bus_drv", 195 .id = UCLASS_I2C, 196 .ops = &i2c_mux_bus_ops, 197 }; 198 199 UCLASS_DRIVER(i2c_mux) = { 200 .id = UCLASS_I2C_MUX, 201 .name = "i2c_mux", 202 .post_bind = i2c_mux_post_bind, 203 .post_probe = i2c_mux_post_probe, 204 .per_device_auto_alloc_size = sizeof(struct i2c_mux), 205 .per_child_platdata_auto_alloc_size = sizeof(struct i2c_mux_bus), 206 .child_post_bind = i2c_mux_child_post_bind, 207 }; 208