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/*
* Copyright (c) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <i2c.h>
#include <dm/lists.h>
#include <dm/root.h>
DECLARE_GLOBAL_DATA_PTR;
/**
* struct i2c_mux: Information the uclass stores about an I2C mux
*
* @selected: Currently selected mux, or -1 for none
* @i2c_bus: I2C bus to use for communcation
*/
struct i2c_mux {
int selected;
struct udevice *i2c_bus;
};
/**
* struct i2c_mux_bus: Information about each bus the mux controls
*
* @channel: Channel number used to select this bus
*/
struct i2c_mux_bus {
uint channel;
};
/* Find out the mux channel number */
static int i2c_mux_child_post_bind(struct udevice *dev)
{
struct i2c_mux_bus *plat = dev_get_parent_platdata(dev);
int channel;
channel = fdtdec_get_int(gd->fdt_blob, dev->of_offset, "reg", -1);
if (channel < 0)
return -EINVAL;
plat->channel = channel;
return 0;
}
/* Find the I2C buses selected by this mux */
static int i2c_mux_post_bind(struct udevice *mux)
{
const void *blob = gd->fdt_blob;
int ret;
int offset;
debug("%s: %s\n", __func__, mux->name);
/*
* There is no compatible string in the sub-nodes, so we must manually
* bind these
*/
for (offset = fdt_first_subnode(blob, mux->of_offset);
offset > 0;
offset = fdt_next_subnode(blob, offset)) {
struct udevice *dev;
const char *name;
name = fdt_get_name(blob, offset, NULL);
ret = device_bind_driver_to_node(mux, "i2c_mux_bus_drv", name,
offset, &dev);
debug(" - bind ret=%d, %s\n", ret, dev ? dev->name : NULL);
if (ret)
return ret;
}
return 0;
}
/* Set up the mux ready for use */
static int i2c_mux_post_probe(struct udevice *mux)
{
struct i2c_mux *priv = dev_get_uclass_priv(mux);
int ret;
debug("%s: %s\n", __func__, mux->name);
priv->selected = -1;
/* if parent is of i2c uclass already, we'll take that, otherwise
* look if we find an i2c-parent phandle
*/
if (UCLASS_I2C == device_get_uclass_id(mux->parent)) {
priv->i2c_bus = dev_get_parent(mux);
debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus,
priv->i2c_bus->name);
return 0;
}
ret = uclass_get_device_by_phandle(UCLASS_I2C, mux, "i2c-parent",
&priv->i2c_bus);
if (ret)
return ret;
debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus, priv->i2c_bus->name);
return 0;
}
int i2c_mux_select(struct udevice *dev)
{
struct i2c_mux_bus *plat = dev_get_parent_platdata(dev);
struct udevice *mux = dev->parent;
struct i2c_mux_ops *ops = i2c_mux_get_ops(mux);
if (!ops->select)
return -ENOSYS;
return ops->select(mux, dev, plat->channel);
}
int i2c_mux_deselect(struct udevice *dev)
{
struct i2c_mux_bus *plat = dev_get_parent_platdata(dev);
struct udevice *mux = dev->parent;
struct i2c_mux_ops *ops = i2c_mux_get_ops(mux);
if (!ops->deselect)
return -ENOSYS;
return ops->deselect(mux, dev, plat->channel);
}
static int i2c_mux_bus_set_bus_speed(struct udevice *dev, unsigned int speed)
{
struct udevice *mux = dev->parent;
struct i2c_mux *priv = dev_get_uclass_priv(mux);
int ret, ret2;
ret = i2c_mux_select(dev);
if (ret)
return ret;
ret = dm_i2c_set_bus_speed(priv->i2c_bus, speed);
ret2 = i2c_mux_deselect(dev);
return ret ? ret : ret2;
}
static int i2c_mux_bus_probe(struct udevice *dev, uint chip_addr,
uint chip_flags)
{
struct udevice *mux = dev->parent;
struct i2c_mux *priv = dev_get_uclass_priv(mux);
struct dm_i2c_ops *ops = i2c_get_ops(priv->i2c_bus);
int ret, ret2;
debug("%s: %s, bus %s\n", __func__, dev->name, priv->i2c_bus->name);
if (!ops->probe_chip)
return -ENOSYS;
ret = i2c_mux_select(dev);
if (ret)
return ret;
ret = ops->probe_chip(priv->i2c_bus, chip_addr, chip_flags);
ret2 = i2c_mux_deselect(dev);
return ret ? ret : ret2;
}
static int i2c_mux_bus_xfer(struct udevice *dev, struct i2c_msg *msg,
int nmsgs)
{
struct udevice *mux = dev->parent;
struct i2c_mux *priv = dev_get_uclass_priv(mux);
struct dm_i2c_ops *ops = i2c_get_ops(priv->i2c_bus);
int ret, ret2;
debug("%s: %s, bus %s\n", __func__, dev->name, priv->i2c_bus->name);
if (!ops->xfer)
return -ENOSYS;
ret = i2c_mux_select(dev);
if (ret)
return ret;
ret = ops->xfer(priv->i2c_bus, msg, nmsgs);
ret2 = i2c_mux_deselect(dev);
return ret ? ret : ret2;
}
static const struct dm_i2c_ops i2c_mux_bus_ops = {
.xfer = i2c_mux_bus_xfer,
.probe_chip = i2c_mux_bus_probe,
.set_bus_speed = i2c_mux_bus_set_bus_speed,
};
U_BOOT_DRIVER(i2c_mux_bus) = {
.name = "i2c_mux_bus_drv",
.id = UCLASS_I2C,
.ops = &i2c_mux_bus_ops,
};
UCLASS_DRIVER(i2c_mux) = {
.id = UCLASS_I2C_MUX,
.name = "i2c_mux",
.post_bind = i2c_mux_post_bind,
.post_probe = i2c_mux_post_probe,
.per_device_auto_alloc_size = sizeof(struct i2c_mux),
.per_child_platdata_auto_alloc_size = sizeof(struct i2c_mux_bus),
.child_post_bind = i2c_mux_child_post_bind,
};
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