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1 | /* |
2 | * Broadcom UniMAC MDIO bus controller driver | |
3 | * | |
4 | * Copyright (C) 2014, Broadcom Corporation | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/phy.h> | |
14 | #include <linux/platform_device.h> | |
15 | #include <linux/sched.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/io.h> | |
18 | #include <linux/delay.h> | |
19 | ||
20 | #include <linux/of.h> | |
21 | #include <linux/of_platform.h> | |
22 | #include <linux/of_mdio.h> | |
23 | ||
24 | #define MDIO_CMD 0x00 | |
25 | #define MDIO_START_BUSY (1 << 29) | |
26 | #define MDIO_READ_FAIL (1 << 28) | |
27 | #define MDIO_RD (2 << 26) | |
28 | #define MDIO_WR (1 << 26) | |
29 | #define MDIO_PMD_SHIFT 21 | |
30 | #define MDIO_PMD_MASK 0x1F | |
31 | #define MDIO_REG_SHIFT 16 | |
32 | #define MDIO_REG_MASK 0x1F | |
33 | ||
34 | #define MDIO_CFG 0x04 | |
35 | #define MDIO_C22 (1 << 0) | |
36 | #define MDIO_C45 0 | |
37 | #define MDIO_CLK_DIV_SHIFT 4 | |
38 | #define MDIO_CLK_DIV_MASK 0x3F | |
39 | #define MDIO_SUPP_PREAMBLE (1 << 12) | |
40 | ||
41 | struct unimac_mdio_priv { | |
42 | struct mii_bus *mii_bus; | |
43 | void __iomem *base; | |
44 | }; | |
45 | ||
46 | static inline void unimac_mdio_start(struct unimac_mdio_priv *priv) | |
47 | { | |
48 | u32 reg; | |
49 | ||
50 | reg = __raw_readl(priv->base + MDIO_CMD); | |
51 | reg |= MDIO_START_BUSY; | |
52 | __raw_writel(reg, priv->base + MDIO_CMD); | |
53 | } | |
54 | ||
55 | static inline unsigned int unimac_mdio_busy(struct unimac_mdio_priv *priv) | |
56 | { | |
57 | return __raw_readl(priv->base + MDIO_CMD) & MDIO_START_BUSY; | |
58 | } | |
59 | ||
60 | static int unimac_mdio_read(struct mii_bus *bus, int phy_id, int reg) | |
61 | { | |
62 | struct unimac_mdio_priv *priv = bus->priv; | |
63 | unsigned int timeout = 1000; | |
64 | u32 cmd; | |
65 | ||
66 | /* Prepare the read operation */ | |
67 | cmd = MDIO_RD | (phy_id << MDIO_PMD_SHIFT) | (reg << MDIO_REG_SHIFT); | |
68 | __raw_writel(cmd, priv->base + MDIO_CMD); | |
69 | ||
70 | /* Start MDIO transaction */ | |
71 | unimac_mdio_start(priv); | |
72 | ||
73 | do { | |
74 | if (!unimac_mdio_busy(priv)) | |
75 | break; | |
76 | ||
77 | usleep_range(1000, 2000); | |
78 | } while (timeout--); | |
79 | ||
80 | if (!timeout) | |
81 | return -ETIMEDOUT; | |
82 | ||
83 | cmd = __raw_readl(priv->base + MDIO_CMD); | |
1a3f4e83 FF |
84 | |
85 | /* Some broken devices are known not to release the line during | |
86 | * turn-around, e.g: Broadcom BCM53125 external switches, so check for | |
87 | * that condition here and ignore the MDIO controller read failure | |
88 | * indication. | |
89 | */ | |
90 | if (!(bus->phy_ignore_ta_mask & 1 << phy_id) && (cmd & MDIO_READ_FAIL)) | |
2ba1b163 FF |
91 | return -EIO; |
92 | ||
93 | return cmd & 0xffff; | |
94 | } | |
95 | ||
96 | static int unimac_mdio_write(struct mii_bus *bus, int phy_id, | |
97 | int reg, u16 val) | |
98 | { | |
99 | struct unimac_mdio_priv *priv = bus->priv; | |
100 | unsigned int timeout = 1000; | |
101 | u32 cmd; | |
102 | ||
103 | /* Prepare the write operation */ | |
104 | cmd = MDIO_WR | (phy_id << MDIO_PMD_SHIFT) | | |
105 | (reg << MDIO_REG_SHIFT) | (0xffff & val); | |
106 | __raw_writel(cmd, priv->base + MDIO_CMD); | |
107 | ||
108 | unimac_mdio_start(priv); | |
109 | ||
110 | do { | |
111 | if (!unimac_mdio_busy(priv)) | |
112 | break; | |
113 | ||
114 | usleep_range(1000, 2000); | |
115 | } while (timeout--); | |
116 | ||
117 | if (!timeout) | |
118 | return -ETIMEDOUT; | |
119 | ||
120 | return 0; | |
121 | } | |
122 | ||
123 | static int unimac_mdio_probe(struct platform_device *pdev) | |
124 | { | |
125 | struct unimac_mdio_priv *priv; | |
126 | struct device_node *np; | |
127 | struct mii_bus *bus; | |
128 | struct resource *r; | |
129 | int ret; | |
130 | ||
131 | np = pdev->dev.of_node; | |
132 | ||
133 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); | |
134 | if (!priv) | |
135 | return -ENOMEM; | |
136 | ||
137 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
138 | ||
139 | /* Just ioremap, as this MDIO block is usually integrated into an | |
140 | * Ethernet MAC controller register range | |
141 | */ | |
142 | priv->base = devm_ioremap(&pdev->dev, r->start, resource_size(r)); | |
143 | if (!priv->base) { | |
144 | dev_err(&pdev->dev, "failed to remap register\n"); | |
145 | return -ENOMEM; | |
146 | } | |
147 | ||
148 | priv->mii_bus = mdiobus_alloc(); | |
149 | if (!priv->mii_bus) | |
150 | return -ENOMEM; | |
151 | ||
152 | bus = priv->mii_bus; | |
153 | bus->priv = priv; | |
154 | bus->name = "unimac MII bus"; | |
155 | bus->parent = &pdev->dev; | |
156 | bus->read = unimac_mdio_read; | |
157 | bus->write = unimac_mdio_write; | |
158 | snprintf(bus->id, MII_BUS_ID_SIZE, "%s", pdev->name); | |
159 | ||
160 | bus->irq = kcalloc(PHY_MAX_ADDR, sizeof(int), GFP_KERNEL); | |
161 | if (!bus->irq) { | |
162 | ret = -ENOMEM; | |
163 | goto out_mdio_free; | |
164 | } | |
165 | ||
166 | ret = of_mdiobus_register(bus, np); | |
167 | if (ret) { | |
168 | dev_err(&pdev->dev, "MDIO bus registration failed\n"); | |
169 | goto out_mdio_irq; | |
170 | } | |
171 | ||
172 | platform_set_drvdata(pdev, priv); | |
173 | ||
174 | dev_info(&pdev->dev, "Broadcom UniMAC MDIO bus at 0x%p\n", priv->base); | |
175 | ||
176 | return 0; | |
177 | ||
178 | out_mdio_irq: | |
179 | kfree(bus->irq); | |
180 | out_mdio_free: | |
181 | mdiobus_free(bus); | |
182 | return ret; | |
183 | } | |
184 | ||
185 | static int unimac_mdio_remove(struct platform_device *pdev) | |
186 | { | |
187 | struct unimac_mdio_priv *priv = platform_get_drvdata(pdev); | |
188 | ||
189 | mdiobus_unregister(priv->mii_bus); | |
190 | kfree(priv->mii_bus->irq); | |
191 | mdiobus_free(priv->mii_bus); | |
192 | ||
193 | return 0; | |
194 | } | |
195 | ||
d8a7dadb | 196 | static const struct of_device_id unimac_mdio_ids[] = { |
2ba1b163 FF |
197 | { .compatible = "brcm,genet-mdio-v4", }, |
198 | { .compatible = "brcm,genet-mdio-v3", }, | |
199 | { .compatible = "brcm,genet-mdio-v2", }, | |
200 | { .compatible = "brcm,genet-mdio-v1", }, | |
201 | { .compatible = "brcm,unimac-mdio", }, | |
4559154a | 202 | { /* sentinel */ }, |
2ba1b163 FF |
203 | }; |
204 | ||
205 | static struct platform_driver unimac_mdio_driver = { | |
206 | .driver = { | |
207 | .name = "unimac-mdio", | |
2ba1b163 FF |
208 | .of_match_table = unimac_mdio_ids, |
209 | }, | |
210 | .probe = unimac_mdio_probe, | |
211 | .remove = unimac_mdio_remove, | |
212 | }; | |
213 | module_platform_driver(unimac_mdio_driver); | |
214 | ||
215 | MODULE_AUTHOR("Broadcom Corporation"); | |
216 | MODULE_DESCRIPTION("Broadcom UniMAC MDIO bus controller"); | |
217 | MODULE_LICENSE("GPL"); | |
218 | MODULE_ALIAS("platform:unimac-mdio"); |