1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * Broadcom BCM6368 mdiomux bus controller driver |
4 | * |
5 | * Copyright (C) 2021 Álvaro Fernández Rojas <noltari@gmail.com> |
6 | */ |
7 | |
8 | #include <linux/delay.h> |
9 | #include <linux/io.h> |
10 | #include <linux/kernel.h> |
11 | #include <linux/mdio-mux.h> |
12 | #include <linux/module.h> |
13 | #include <linux/of.h> |
14 | #include <linux/of_platform.h> |
15 | #include <linux/of_mdio.h> |
16 | #include <linux/phy.h> |
17 | #include <linux/platform_device.h> |
18 | #include <linux/sched.h> |
19 | |
20 | #define MDIOC_REG 0x0 |
21 | #define MDIOC_EXT_MASK BIT(16) |
22 | #define MDIOC_REG_SHIFT 20 |
23 | #define MDIOC_PHYID_SHIFT 25 |
24 | #define MDIOC_RD_MASK BIT(30) |
25 | #define MDIOC_WR_MASK BIT(31) |
26 | |
27 | #define MDIOD_REG 0x4 |
28 | |
29 | struct bcm6368_mdiomux_desc { |
30 | void *mux_handle; |
31 | void __iomem *base; |
32 | struct device *dev; |
33 | struct mii_bus *mii_bus; |
34 | int ext_phy; |
35 | }; |
36 | |
37 | static int bcm6368_mdiomux_read(struct mii_bus *bus, int phy_id, int loc) |
38 | { |
39 | struct bcm6368_mdiomux_desc *md = bus->priv; |
40 | uint32_t reg; |
41 | int ret; |
42 | |
43 | __raw_writel(val: 0, addr: md->base + MDIOC_REG); |
44 | |
45 | reg = MDIOC_RD_MASK | |
46 | (phy_id << MDIOC_PHYID_SHIFT) | |
47 | (loc << MDIOC_REG_SHIFT); |
48 | if (md->ext_phy) |
49 | reg |= MDIOC_EXT_MASK; |
50 | |
51 | __raw_writel(val: reg, addr: md->base + MDIOC_REG); |
52 | udelay(50); |
53 | ret = __raw_readw(addr: md->base + MDIOD_REG); |
54 | |
55 | return ret; |
56 | } |
57 | |
58 | static int bcm6368_mdiomux_write(struct mii_bus *bus, int phy_id, int loc, |
59 | uint16_t val) |
60 | { |
61 | struct bcm6368_mdiomux_desc *md = bus->priv; |
62 | uint32_t reg; |
63 | |
64 | __raw_writel(val: 0, addr: md->base + MDIOC_REG); |
65 | |
66 | reg = MDIOC_WR_MASK | |
67 | (phy_id << MDIOC_PHYID_SHIFT) | |
68 | (loc << MDIOC_REG_SHIFT); |
69 | if (md->ext_phy) |
70 | reg |= MDIOC_EXT_MASK; |
71 | reg |= val; |
72 | |
73 | __raw_writel(val: reg, addr: md->base + MDIOC_REG); |
74 | udelay(50); |
75 | |
76 | return 0; |
77 | } |
78 | |
79 | static int bcm6368_mdiomux_switch_fn(int current_child, int desired_child, |
80 | void *data) |
81 | { |
82 | struct bcm6368_mdiomux_desc *md = data; |
83 | |
84 | md->ext_phy = desired_child; |
85 | |
86 | return 0; |
87 | } |
88 | |
89 | static int bcm6368_mdiomux_probe(struct platform_device *pdev) |
90 | { |
91 | struct bcm6368_mdiomux_desc *md; |
92 | struct mii_bus *bus; |
93 | struct resource *res; |
94 | int rc; |
95 | |
96 | md = devm_kzalloc(dev: &pdev->dev, size: sizeof(*md), GFP_KERNEL); |
97 | if (!md) |
98 | return -ENOMEM; |
99 | md->dev = &pdev->dev; |
100 | |
101 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
102 | if (!res) |
103 | return -EINVAL; |
104 | |
105 | /* |
106 | * Just ioremap, as this MDIO block is usually integrated into an |
107 | * Ethernet MAC controller register range |
108 | */ |
109 | md->base = devm_ioremap(dev: &pdev->dev, offset: res->start, size: resource_size(res)); |
110 | if (!md->base) { |
111 | dev_err(&pdev->dev, "failed to ioremap register\n" ); |
112 | return -ENOMEM; |
113 | } |
114 | |
115 | md->mii_bus = devm_mdiobus_alloc(dev: &pdev->dev); |
116 | if (!md->mii_bus) { |
117 | dev_err(&pdev->dev, "mdiomux bus alloc failed\n" ); |
118 | return -ENOMEM; |
119 | } |
120 | |
121 | bus = md->mii_bus; |
122 | bus->priv = md; |
123 | bus->name = "BCM6368 MDIO mux bus" ; |
124 | snprintf(buf: bus->id, MII_BUS_ID_SIZE, fmt: "%s-%d" , pdev->name, pdev->id); |
125 | bus->parent = &pdev->dev; |
126 | bus->read = bcm6368_mdiomux_read; |
127 | bus->write = bcm6368_mdiomux_write; |
128 | bus->phy_mask = 0x3f; |
129 | bus->dev.of_node = pdev->dev.of_node; |
130 | |
131 | rc = mdiobus_register(bus); |
132 | if (rc) { |
133 | dev_err(&pdev->dev, "mdiomux registration failed\n" ); |
134 | return rc; |
135 | } |
136 | |
137 | platform_set_drvdata(pdev, data: md); |
138 | |
139 | rc = mdio_mux_init(dev: md->dev, mux_node: md->dev->of_node, |
140 | switch_fn: bcm6368_mdiomux_switch_fn, mux_handle: &md->mux_handle, data: md, |
141 | mux_bus: md->mii_bus); |
142 | if (rc) { |
143 | dev_info(md->dev, "mdiomux initialization failed\n" ); |
144 | goto out_register; |
145 | } |
146 | |
147 | dev_info(&pdev->dev, "Broadcom BCM6368 MDIO mux bus\n" ); |
148 | |
149 | return 0; |
150 | |
151 | out_register: |
152 | mdiobus_unregister(bus); |
153 | return rc; |
154 | } |
155 | |
156 | static void bcm6368_mdiomux_remove(struct platform_device *pdev) |
157 | { |
158 | struct bcm6368_mdiomux_desc *md = platform_get_drvdata(pdev); |
159 | |
160 | mdio_mux_uninit(mux_handle: md->mux_handle); |
161 | mdiobus_unregister(bus: md->mii_bus); |
162 | } |
163 | |
164 | static const struct of_device_id bcm6368_mdiomux_ids[] = { |
165 | { .compatible = "brcm,bcm6368-mdio-mux" , }, |
166 | { /* sentinel */ } |
167 | }; |
168 | MODULE_DEVICE_TABLE(of, bcm6368_mdiomux_ids); |
169 | |
170 | static struct platform_driver bcm6368_mdiomux_driver = { |
171 | .driver = { |
172 | .name = "bcm6368-mdio-mux" , |
173 | .of_match_table = bcm6368_mdiomux_ids, |
174 | }, |
175 | .probe = bcm6368_mdiomux_probe, |
176 | .remove_new = bcm6368_mdiomux_remove, |
177 | }; |
178 | module_platform_driver(bcm6368_mdiomux_driver); |
179 | |
180 | MODULE_AUTHOR("Álvaro Fernández Rojas <noltari@gmail.com>" ); |
181 | MODULE_DESCRIPTION("BCM6368 mdiomux bus controller driver" ); |
182 | MODULE_LICENSE("GPL v2" ); |
183 | |