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- // SPDX-License-Identifier: GPL-2.0+
- /*
- * (C) Copyright 2019
- * Alex Marginean, NXP
- */
- #include <dm.h>
- #include <errno.h>
- #include <log.h>
- #include <miiphy.h>
- #include <i2c.h>
- /*
- * This driver is used for MDIO muxes driven by writing to a register of an I2C
- * chip. The board it was developed for uses a mux controlled by on-board FPGA
- * which in turn is accessed as a chip over I2C.
- */
- struct mdio_mux_i2creg_priv {
- struct udevice *chip;
- int reg;
- int mask;
- };
- static int mdio_mux_i2creg_select(struct udevice *mux, int cur, int sel)
- {
- struct mdio_mux_i2creg_priv *priv = dev_get_priv(mux);
- u8 val, val_old;
- /* if last selection didn't change we're good to go */
- if (cur == sel)
- return 0;
- val_old = dm_i2c_reg_read(priv->chip, priv->reg);
- val = (val_old & ~priv->mask) | (sel & priv->mask);
- debug("%s: chip %s, reg %x, val %x => %x\n", __func__, priv->chip->name,
- priv->reg, val_old, val);
- dm_i2c_reg_write(priv->chip, priv->reg, val);
- return 0;
- }
- static const struct mdio_mux_ops mdio_mux_i2creg_ops = {
- .select = mdio_mux_i2creg_select,
- };
- static int mdio_mux_i2creg_probe(struct udevice *dev)
- {
- struct mdio_mux_i2creg_priv *priv = dev_get_priv(dev);
- ofnode chip_node, bus_node;
- struct udevice *i2c_bus;
- u32 reg_mask[2];
- u32 chip_addr;
- int err;
- /* read the register addr/mask pair */
- err = dev_read_u32_array(dev, "mux-reg-masks", reg_mask, 2);
- if (err) {
- debug("%s: error reading mux-reg-masks property\n", __func__);
- return err;
- }
- /* parent should be an I2C chip, grandparent should be an I2C bus */
- chip_node = ofnode_get_parent(dev->node);
- bus_node = ofnode_get_parent(chip_node);
- err = uclass_get_device_by_ofnode(UCLASS_I2C, bus_node, &i2c_bus);
- if (err) {
- debug("%s: can't find I2C bus for node %s\n", __func__,
- ofnode_get_name(bus_node));
- return err;
- }
- err = ofnode_read_u32(chip_node, "reg", &chip_addr);
- if (err) {
- debug("%s: can't read chip address in %s\n", __func__,
- ofnode_get_name(chip_node));
- return err;
- }
- err = i2c_get_chip(i2c_bus, (uint)chip_addr, 1, &priv->chip);
- if (err) {
- debug("%s: can't find i2c chip device for addr %x\n", __func__,
- chip_addr);
- return err;
- }
- priv->reg = (int)reg_mask[0];
- priv->mask = (int)reg_mask[1];
- debug("%s: chip %s, reg %x, mask %x\n", __func__, priv->chip->name,
- priv->reg, priv->mask);
- return 0;
- }
- static const struct udevice_id mdio_mux_i2creg_ids[] = {
- { .compatible = "mdio-mux-i2creg" },
- { }
- };
- U_BOOT_DRIVER(mdio_mux_i2creg) = {
- .name = "mdio_mux_i2creg",
- .id = UCLASS_MDIO_MUX,
- .of_match = mdio_mux_i2creg_ids,
- .probe = mdio_mux_i2creg_probe,
- .ops = &mdio_mux_i2creg_ops,
- .priv_auto_alloc_size = sizeof(struct mdio_mux_i2creg_priv),
- };
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