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2ba1b163 FF |
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 | ||
d8e704e4 FF |
123 | /* Workaround for integrated BCM7xxx Gigabit PHYs which have a problem with |
124 | * their internal MDIO management controller making them fail to successfully | |
125 | * be read from or written to for the first transaction. We insert a dummy | |
126 | * BMSR read here to make sure that phy_get_device() and get_phy_id() can | |
127 | * correctly read the PHY MII_PHYSID1/2 registers and successfully register a | |
128 | * PHY device for this peripheral. | |
129 | * | |
130 | * Once the PHY driver is registered, we can workaround subsequent reads from | |
131 | * there (e.g: during system-wide power management). | |
132 | * | |
133 | * bus->reset is invoked before mdiobus_scan during mdiobus_register and is | |
134 | * therefore the right location to stick that workaround. Since we do not want | |
135 | * to read from non-existing PHYs, we either use bus->phy_mask or do a manual | |
136 | * Device Tree scan to limit the search area. | |
137 | */ | |
138 | static int unimac_mdio_reset(struct mii_bus *bus) | |
139 | { | |
140 | struct device_node *np = bus->dev.of_node; | |
141 | struct device_node *child; | |
142 | u32 read_mask = 0; | |
143 | int addr; | |
144 | ||
145 | if (!np) { | |
146 | read_mask = ~bus->phy_mask; | |
147 | } else { | |
148 | for_each_available_child_of_node(np, child) { | |
149 | addr = of_mdio_parse_addr(&bus->dev, child); | |
150 | if (addr < 0) | |
151 | continue; | |
152 | ||
153 | read_mask |= 1 << addr; | |
154 | } | |
155 | } | |
156 | ||
157 | for (addr = 0; addr < PHY_MAX_ADDR; addr++) { | |
158 | if (read_mask & 1 << addr) | |
159 | mdiobus_read(bus, addr, MII_BMSR); | |
160 | } | |
161 | ||
162 | return 0; | |
163 | } | |
164 | ||
2ba1b163 FF |
165 | static int unimac_mdio_probe(struct platform_device *pdev) |
166 | { | |
167 | struct unimac_mdio_priv *priv; | |
168 | struct device_node *np; | |
169 | struct mii_bus *bus; | |
170 | struct resource *r; | |
171 | int ret; | |
172 | ||
173 | np = pdev->dev.of_node; | |
174 | ||
175 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); | |
176 | if (!priv) | |
177 | return -ENOMEM; | |
178 | ||
179 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
180 | ||
181 | /* Just ioremap, as this MDIO block is usually integrated into an | |
182 | * Ethernet MAC controller register range | |
183 | */ | |
184 | priv->base = devm_ioremap(&pdev->dev, r->start, resource_size(r)); | |
185 | if (!priv->base) { | |
186 | dev_err(&pdev->dev, "failed to remap register\n"); | |
187 | return -ENOMEM; | |
188 | } | |
189 | ||
190 | priv->mii_bus = mdiobus_alloc(); | |
191 | if (!priv->mii_bus) | |
192 | return -ENOMEM; | |
193 | ||
194 | bus = priv->mii_bus; | |
195 | bus->priv = priv; | |
196 | bus->name = "unimac MII bus"; | |
197 | bus->parent = &pdev->dev; | |
198 | bus->read = unimac_mdio_read; | |
199 | bus->write = unimac_mdio_write; | |
d8e704e4 | 200 | bus->reset = unimac_mdio_reset; |
2ba1b163 FF |
201 | snprintf(bus->id, MII_BUS_ID_SIZE, "%s", pdev->name); |
202 | ||
2ba1b163 FF |
203 | ret = of_mdiobus_register(bus, np); |
204 | if (ret) { | |
205 | dev_err(&pdev->dev, "MDIO bus registration failed\n"); | |
e7f4dc35 | 206 | goto out_mdio_free; |
2ba1b163 FF |
207 | } |
208 | ||
209 | platform_set_drvdata(pdev, priv); | |
210 | ||
211 | dev_info(&pdev->dev, "Broadcom UniMAC MDIO bus at 0x%p\n", priv->base); | |
212 | ||
213 | return 0; | |
214 | ||
2ba1b163 FF |
215 | out_mdio_free: |
216 | mdiobus_free(bus); | |
217 | return ret; | |
218 | } | |
219 | ||
220 | static int unimac_mdio_remove(struct platform_device *pdev) | |
221 | { | |
222 | struct unimac_mdio_priv *priv = platform_get_drvdata(pdev); | |
223 | ||
224 | mdiobus_unregister(priv->mii_bus); | |
2ba1b163 FF |
225 | mdiobus_free(priv->mii_bus); |
226 | ||
227 | return 0; | |
228 | } | |
229 | ||
d8a7dadb | 230 | static const struct of_device_id unimac_mdio_ids[] = { |
2ba1b163 FF |
231 | { .compatible = "brcm,genet-mdio-v4", }, |
232 | { .compatible = "brcm,genet-mdio-v3", }, | |
233 | { .compatible = "brcm,genet-mdio-v2", }, | |
234 | { .compatible = "brcm,genet-mdio-v1", }, | |
235 | { .compatible = "brcm,unimac-mdio", }, | |
4559154a | 236 | { /* sentinel */ }, |
2ba1b163 | 237 | }; |
2f90a307 | 238 | MODULE_DEVICE_TABLE(of, unimac_mdio_ids); |
2ba1b163 FF |
239 | |
240 | static struct platform_driver unimac_mdio_driver = { | |
241 | .driver = { | |
242 | .name = "unimac-mdio", | |
2ba1b163 FF |
243 | .of_match_table = unimac_mdio_ids, |
244 | }, | |
245 | .probe = unimac_mdio_probe, | |
246 | .remove = unimac_mdio_remove, | |
247 | }; | |
248 | module_platform_driver(unimac_mdio_driver); | |
249 | ||
250 | MODULE_AUTHOR("Broadcom Corporation"); | |
251 | MODULE_DESCRIPTION("Broadcom UniMAC MDIO bus controller"); | |
252 | MODULE_LICENSE("GPL"); | |
253 | MODULE_ALIAS("platform:unimac-mdio"); |