1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* Driver for MMIO-Mapped MDIO devices. Some IPs expose internal PHYs or PCS |
3 | * within the MMIO-mapped area |
4 | * |
5 | * Copyright (C) 2023 Maxime Chevallier <maxime.chevallier@bootlin.com> |
6 | */ |
7 | #include <linux/bitfield.h> |
8 | #include <linux/delay.h> |
9 | #include <linux/mdio.h> |
10 | #include <linux/module.h> |
11 | #include <linux/of.h> |
12 | #include <linux/of_mdio.h> |
13 | #include <linux/phy.h> |
14 | #include <linux/platform_device.h> |
15 | #include <linux/regmap.h> |
16 | #include <linux/mdio/mdio-regmap.h> |
17 | |
18 | #define DRV_NAME "mdio-regmap" |
19 | |
20 | struct mdio_regmap_priv { |
21 | struct regmap *regmap; |
22 | u8 valid_addr; |
23 | }; |
24 | |
25 | static int mdio_regmap_read_c22(struct mii_bus *bus, int addr, int regnum) |
26 | { |
27 | struct mdio_regmap_priv *ctx = bus->priv; |
28 | unsigned int val; |
29 | int ret; |
30 | |
31 | if (ctx->valid_addr != addr) |
32 | return -ENODEV; |
33 | |
34 | ret = regmap_read(map: ctx->regmap, reg: regnum, val: &val); |
35 | if (ret < 0) |
36 | return ret; |
37 | |
38 | return val; |
39 | } |
40 | |
41 | static int mdio_regmap_write_c22(struct mii_bus *bus, int addr, int regnum, |
42 | u16 val) |
43 | { |
44 | struct mdio_regmap_priv *ctx = bus->priv; |
45 | |
46 | if (ctx->valid_addr != addr) |
47 | return -ENODEV; |
48 | |
49 | return regmap_write(map: ctx->regmap, reg: regnum, val); |
50 | } |
51 | |
52 | struct mii_bus *devm_mdio_regmap_register(struct device *dev, |
53 | const struct mdio_regmap_config *config) |
54 | { |
55 | struct mdio_regmap_priv *mr; |
56 | struct mii_bus *mii; |
57 | int rc; |
58 | |
59 | if (!config->parent) |
60 | return ERR_PTR(error: -EINVAL); |
61 | |
62 | mii = devm_mdiobus_alloc_size(dev: config->parent, sizeof_priv: sizeof(*mr)); |
63 | if (!mii) |
64 | return ERR_PTR(error: -ENOMEM); |
65 | |
66 | mr = mii->priv; |
67 | mr->regmap = config->regmap; |
68 | mr->valid_addr = config->valid_addr; |
69 | |
70 | mii->name = DRV_NAME; |
71 | strscpy(mii->id, config->name, MII_BUS_ID_SIZE); |
72 | mii->parent = config->parent; |
73 | mii->read = mdio_regmap_read_c22; |
74 | mii->write = mdio_regmap_write_c22; |
75 | |
76 | if (config->autoscan) |
77 | mii->phy_mask = ~BIT(config->valid_addr); |
78 | else |
79 | mii->phy_mask = ~0; |
80 | |
81 | rc = devm_mdiobus_register(dev, mii); |
82 | if (rc) { |
83 | dev_err(config->parent, "Cannot register MDIO bus![%s] (%d)\n" , mii->id, rc); |
84 | return ERR_PTR(error: rc); |
85 | } |
86 | |
87 | return mii; |
88 | } |
89 | EXPORT_SYMBOL_GPL(devm_mdio_regmap_register); |
90 | |
91 | MODULE_DESCRIPTION("MDIO API over regmap" ); |
92 | MODULE_AUTHOR("Maxime Chevallier <maxime.chevallier@bootlin.com>" ); |
93 | MODULE_LICENSE("GPL" ); |
94 | |