diff options
Diffstat (limited to 'roms/u-boot/drivers/i2c/muxes/i2c-mux-uclass.c')
| -rw-r--r-- | roms/u-boot/drivers/i2c/muxes/i2c-mux-uclass.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/i2c/muxes/i2c-mux-uclass.c b/roms/u-boot/drivers/i2c/muxes/i2c-mux-uclass.c new file mode 100644 index 000000000..dbca409ee --- /dev/null +++ b/roms/u-boot/drivers/i2c/muxes/i2c-mux-uclass.c @@ -0,0 +1,226 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2015 Google, Inc + * Written by Simon Glass <sjg@chromium.org> + */ + +#include <common.h> +#include <dm.h> +#include <errno.h> +#include <i2c.h> +#include <log.h> +#include <malloc.h> +#include <dm/lists.h> +#include <dm/root.h> + +/** + * 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_plat(dev); + int channel; + + channel = dev_read_u32_default(dev, "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) +{ + ofnode node; + int ret; + + debug("%s: %s\n", __func__, mux->name); + /* + * There is no compatible string in the sub-nodes, so we must manually + * bind these + */ + dev_for_each_subnode(node, mux) { + struct udevice *dev; + const char *name; + const char *arrow = "->"; + char *full_name; + int parent_name_len, arrow_len, mux_name_len, name_len; + + name = ofnode_get_name(node); + + /* Calculate lenghts of strings */ + parent_name_len = strlen(mux->parent->name); + arrow_len = strlen(arrow); + mux_name_len = strlen(mux->name); + name_len = strlen(name); + + full_name = calloc(1, parent_name_len + arrow_len + + mux_name_len + arrow_len + name_len + 1); + if (!full_name) + return -ENOMEM; + + /* Compose bus name */ + strcat(full_name, mux->parent->name); + strcat(full_name, arrow); + strcat(full_name, mux->name); + strcat(full_name, arrow); + strcat(full_name, name); + + ret = device_bind_driver_to_node(mux, "i2c_mux_bus_drv", + full_name, node, &dev); + debug(" - bind ret=%d, %s, seq %d\n", ret, + dev ? dev->name : NULL, dev_seq(dev)); + 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_plat(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_plat(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 = sizeof(struct i2c_mux), + .per_child_plat_auto = sizeof(struct i2c_mux_bus), + .child_post_bind = i2c_mux_child_post_bind, +}; |