Alex Marginean | 3234a5e | 2019-07-16 11:21:17 +0300 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * (C) Copyright 2019 |
| 4 | * Alex Marginean, NXP |
| 5 | */ |
| 6 | |
| 7 | #include <dm.h> |
| 8 | #include <errno.h> |
Simon Glass | 0f2af88 | 2020-05-10 11:40:05 -0600 | [diff] [blame] | 9 | #include <log.h> |
Alex Marginean | 3234a5e | 2019-07-16 11:21:17 +0300 | [diff] [blame] | 10 | #include <miiphy.h> |
| 11 | #include <i2c.h> |
| 12 | |
| 13 | /* |
| 14 | * This driver is used for MDIO muxes driven by writing to a register of an I2C |
| 15 | * chip. The board it was developed for uses a mux controlled by on-board FPGA |
| 16 | * which in turn is accessed as a chip over I2C. |
| 17 | */ |
| 18 | |
| 19 | struct mdio_mux_i2creg_priv { |
| 20 | struct udevice *chip; |
| 21 | int reg; |
| 22 | int mask; |
| 23 | }; |
| 24 | |
| 25 | static int mdio_mux_i2creg_select(struct udevice *mux, int cur, int sel) |
| 26 | { |
| 27 | struct mdio_mux_i2creg_priv *priv = dev_get_priv(mux); |
| 28 | u8 val, val_old; |
| 29 | |
| 30 | /* if last selection didn't change we're good to go */ |
| 31 | if (cur == sel) |
| 32 | return 0; |
| 33 | |
| 34 | val_old = dm_i2c_reg_read(priv->chip, priv->reg); |
| 35 | val = (val_old & ~priv->mask) | (sel & priv->mask); |
| 36 | debug("%s: chip %s, reg %x, val %x => %x\n", __func__, priv->chip->name, |
| 37 | priv->reg, val_old, val); |
| 38 | dm_i2c_reg_write(priv->chip, priv->reg, val); |
| 39 | |
| 40 | return 0; |
| 41 | } |
| 42 | |
| 43 | static const struct mdio_mux_ops mdio_mux_i2creg_ops = { |
| 44 | .select = mdio_mux_i2creg_select, |
| 45 | }; |
| 46 | |
| 47 | static int mdio_mux_i2creg_probe(struct udevice *dev) |
| 48 | { |
| 49 | struct mdio_mux_i2creg_priv *priv = dev_get_priv(dev); |
| 50 | ofnode chip_node, bus_node; |
| 51 | struct udevice *i2c_bus; |
| 52 | u32 reg_mask[2]; |
| 53 | u32 chip_addr; |
| 54 | int err; |
| 55 | |
| 56 | /* read the register addr/mask pair */ |
| 57 | err = dev_read_u32_array(dev, "mux-reg-masks", reg_mask, 2); |
| 58 | if (err) { |
| 59 | debug("%s: error reading mux-reg-masks property\n", __func__); |
| 60 | return err; |
| 61 | } |
| 62 | |
| 63 | /* parent should be an I2C chip, grandparent should be an I2C bus */ |
| 64 | chip_node = ofnode_get_parent(dev->node); |
| 65 | bus_node = ofnode_get_parent(chip_node); |
| 66 | |
| 67 | err = uclass_get_device_by_ofnode(UCLASS_I2C, bus_node, &i2c_bus); |
| 68 | if (err) { |
| 69 | debug("%s: can't find I2C bus for node %s\n", __func__, |
| 70 | ofnode_get_name(bus_node)); |
| 71 | return err; |
| 72 | } |
| 73 | |
| 74 | err = ofnode_read_u32(chip_node, "reg", &chip_addr); |
| 75 | if (err) { |
| 76 | debug("%s: can't read chip address in %s\n", __func__, |
| 77 | ofnode_get_name(chip_node)); |
| 78 | return err; |
| 79 | } |
| 80 | |
| 81 | err = i2c_get_chip(i2c_bus, (uint)chip_addr, 1, &priv->chip); |
| 82 | if (err) { |
| 83 | debug("%s: can't find i2c chip device for addr %x\n", __func__, |
| 84 | chip_addr); |
| 85 | return err; |
| 86 | } |
| 87 | |
| 88 | priv->reg = (int)reg_mask[0]; |
| 89 | priv->mask = (int)reg_mask[1]; |
| 90 | |
| 91 | debug("%s: chip %s, reg %x, mask %x\n", __func__, priv->chip->name, |
| 92 | priv->reg, priv->mask); |
| 93 | |
| 94 | return 0; |
| 95 | } |
| 96 | |
| 97 | static const struct udevice_id mdio_mux_i2creg_ids[] = { |
| 98 | { .compatible = "mdio-mux-i2creg" }, |
| 99 | { } |
| 100 | }; |
| 101 | |
| 102 | U_BOOT_DRIVER(mdio_mux_i2creg) = { |
| 103 | .name = "mdio_mux_i2creg", |
| 104 | .id = UCLASS_MDIO_MUX, |
| 105 | .of_match = mdio_mux_i2creg_ids, |
| 106 | .probe = mdio_mux_i2creg_probe, |
| 107 | .ops = &mdio_mux_i2creg_ops, |
Simon Glass | 8a2b47f | 2020-12-03 16:55:17 -0700 | [diff] [blame] | 108 | .priv_auto = sizeof(struct mdio_mux_i2creg_priv), |
Alex Marginean | 3234a5e | 2019-07-16 11:21:17 +0300 | [diff] [blame] | 109 | }; |