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Commit | Line | Data |
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fc8f5ade TP |
1 | /* |
2 | * Driver for the MDIO interface of Marvell network interfaces. | |
3 | * | |
4 | * Since the MDIO interface of Marvell network interfaces is shared | |
5 | * between all network interfaces, having a single driver allows to | |
6 | * handle concurrent accesses properly (you may have four Ethernet | |
d4a0acb8 LB |
7 | * ports, but they in fact share the same SMI interface to access |
8 | * the MDIO bus). This driver is currently used by the mvneta and | |
9 | * mv643xx_eth drivers. | |
fc8f5ade TP |
10 | * |
11 | * Copyright (C) 2012 Marvell | |
12 | * | |
13 | * Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | |
14 | * | |
15 | * This file is licensed under the terms of the GNU General Public | |
16 | * License version 2. This program is licensed "as is" without any | |
17 | * warranty of any kind, whether express or implied. | |
18 | */ | |
19 | ||
20 | #include <linux/init.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/mutex.h> | |
24 | #include <linux/phy.h> | |
2ec98521 | 25 | #include <linux/interrupt.h> |
fc8f5ade | 26 | #include <linux/platform_device.h> |
d98a80f5 | 27 | #include <linux/delay.h> |
7111b717 | 28 | #include <linux/io.h> |
3d604da1 | 29 | #include <linux/clk.h> |
7111b717 | 30 | #include <linux/of_mdio.h> |
2ec98521 FF |
31 | #include <linux/sched.h> |
32 | #include <linux/wait.h> | |
fc8f5ade TP |
33 | |
34 | #define MVMDIO_SMI_DATA_SHIFT 0 | |
35 | #define MVMDIO_SMI_PHY_ADDR_SHIFT 16 | |
36 | #define MVMDIO_SMI_PHY_REG_SHIFT 21 | |
37 | #define MVMDIO_SMI_READ_OPERATION BIT(26) | |
38 | #define MVMDIO_SMI_WRITE_OPERATION 0 | |
39 | #define MVMDIO_SMI_READ_VALID BIT(27) | |
40 | #define MVMDIO_SMI_BUSY BIT(28) | |
2ec98521 FF |
41 | #define MVMDIO_ERR_INT_CAUSE 0x007C |
42 | #define MVMDIO_ERR_INT_SMI_DONE 0x00000010 | |
43 | #define MVMDIO_ERR_INT_MASK 0x0080 | |
fc8f5ade | 44 | |
b70cd1c1 LB |
45 | /* |
46 | * SMI Timeout measurements: | |
47 | * - Kirkwood 88F6281 (Globalscale Dreamplug): 45us to 95us (Interrupt) | |
48 | * - Armada 370 (Globalscale Mirabox): 41us to 43us (Polled) | |
49 | */ | |
50 | #define MVMDIO_SMI_TIMEOUT 1000 /* 1000us = 1ms */ | |
51 | #define MVMDIO_SMI_POLL_INTERVAL_MIN 45 | |
52 | #define MVMDIO_SMI_POLL_INTERVAL_MAX 55 | |
53 | ||
fc8f5ade TP |
54 | struct orion_mdio_dev { |
55 | struct mutex lock; | |
3712b717 | 56 | void __iomem *regs; |
3d604da1 | 57 | struct clk *clk; |
2ec98521 FF |
58 | /* |
59 | * If we have access to the error interrupt pin (which is | |
60 | * somewhat misnamed as it not only reflects internal errors | |
61 | * but also reflects SMI completion), use that to wait for | |
62 | * SMI access completion instead of polling the SMI busy bit. | |
63 | */ | |
64 | int err_interrupt; | |
65 | wait_queue_head_t smi_busy_wait; | |
fc8f5ade TP |
66 | }; |
67 | ||
2ec98521 FF |
68 | static int orion_mdio_smi_is_done(struct orion_mdio_dev *dev) |
69 | { | |
70 | return !(readl(dev->regs) & MVMDIO_SMI_BUSY); | |
71 | } | |
72 | ||
b07812f1 | 73 | /* Wait for the SMI unit to be ready for another operation |
fc8f5ade TP |
74 | */ |
75 | static int orion_mdio_wait_ready(struct mii_bus *bus) | |
76 | { | |
77 | struct orion_mdio_dev *dev = bus->priv; | |
b70cd1c1 LB |
78 | unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT); |
79 | unsigned long end = jiffies + timeout; | |
80 | int timedout = 0; | |
fc8f5ade | 81 | |
b70cd1c1 LB |
82 | while (1) { |
83 | if (orion_mdio_smi_is_done(dev)) | |
84 | return 0; | |
85 | else if (timedout) | |
86 | break; | |
fc8f5ade | 87 | |
b70cd1c1 LB |
88 | if (dev->err_interrupt <= 0) { |
89 | usleep_range(MVMDIO_SMI_POLL_INTERVAL_MIN, | |
90 | MVMDIO_SMI_POLL_INTERVAL_MAX); | |
fc8f5ade | 91 | |
b70cd1c1 LB |
92 | if (time_is_before_jiffies(end)) |
93 | ++timedout; | |
94 | } else { | |
1a1f20bc LB |
95 | /* wait_event_timeout does not guarantee a delay of at |
96 | * least one whole jiffie, so timeout must be no less | |
97 | * than two. | |
98 | */ | |
99 | if (timeout < 2) | |
100 | timeout = 2; | |
2ec98521 | 101 | wait_event_timeout(dev->smi_busy_wait, |
b70cd1c1 LB |
102 | orion_mdio_smi_is_done(dev), |
103 | timeout); | |
104 | ||
105 | ++timedout; | |
106 | } | |
fc8f5ade TP |
107 | } |
108 | ||
b70cd1c1 LB |
109 | dev_err(bus->parent, "Timeout: SMI busy for too long\n"); |
110 | return -ETIMEDOUT; | |
fc8f5ade TP |
111 | } |
112 | ||
113 | static int orion_mdio_read(struct mii_bus *bus, int mii_id, | |
114 | int regnum) | |
115 | { | |
116 | struct orion_mdio_dev *dev = bus->priv; | |
fc8f5ade TP |
117 | u32 val; |
118 | int ret; | |
119 | ||
120 | mutex_lock(&dev->lock); | |
121 | ||
122 | ret = orion_mdio_wait_ready(bus); | |
839f46bb LB |
123 | if (ret < 0) |
124 | goto out; | |
fc8f5ade TP |
125 | |
126 | writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) | | |
127 | (regnum << MVMDIO_SMI_PHY_REG_SHIFT) | | |
128 | MVMDIO_SMI_READ_OPERATION), | |
3712b717 | 129 | dev->regs); |
fc8f5ade | 130 | |
839f46bb LB |
131 | ret = orion_mdio_wait_ready(bus); |
132 | if (ret < 0) | |
133 | goto out; | |
134 | ||
135 | val = readl(dev->regs); | |
136 | if (!(val & MVMDIO_SMI_READ_VALID)) { | |
137 | dev_err(bus->parent, "SMI bus read not valid\n"); | |
138 | ret = -ENODEV; | |
139 | goto out; | |
fc8f5ade TP |
140 | } |
141 | ||
839f46bb LB |
142 | ret = val & 0xFFFF; |
143 | out: | |
fc8f5ade | 144 | mutex_unlock(&dev->lock); |
839f46bb | 145 | return ret; |
fc8f5ade TP |
146 | } |
147 | ||
148 | static int orion_mdio_write(struct mii_bus *bus, int mii_id, | |
149 | int regnum, u16 value) | |
150 | { | |
151 | struct orion_mdio_dev *dev = bus->priv; | |
152 | int ret; | |
153 | ||
154 | mutex_lock(&dev->lock); | |
155 | ||
156 | ret = orion_mdio_wait_ready(bus); | |
526edcf5 LB |
157 | if (ret < 0) |
158 | goto out; | |
fc8f5ade TP |
159 | |
160 | writel(((mii_id << MVMDIO_SMI_PHY_ADDR_SHIFT) | | |
161 | (regnum << MVMDIO_SMI_PHY_REG_SHIFT) | | |
162 | MVMDIO_SMI_WRITE_OPERATION | | |
163 | (value << MVMDIO_SMI_DATA_SHIFT)), | |
3712b717 | 164 | dev->regs); |
fc8f5ade | 165 | |
526edcf5 | 166 | out: |
fc8f5ade | 167 | mutex_unlock(&dev->lock); |
526edcf5 | 168 | return ret; |
fc8f5ade TP |
169 | } |
170 | ||
171 | static int orion_mdio_reset(struct mii_bus *bus) | |
172 | { | |
173 | return 0; | |
174 | } | |
175 | ||
2ec98521 FF |
176 | static irqreturn_t orion_mdio_err_irq(int irq, void *dev_id) |
177 | { | |
178 | struct orion_mdio_dev *dev = dev_id; | |
179 | ||
180 | if (readl(dev->regs + MVMDIO_ERR_INT_CAUSE) & | |
181 | MVMDIO_ERR_INT_SMI_DONE) { | |
182 | writel(~MVMDIO_ERR_INT_SMI_DONE, | |
183 | dev->regs + MVMDIO_ERR_INT_CAUSE); | |
184 | wake_up(&dev->smi_busy_wait); | |
185 | return IRQ_HANDLED; | |
186 | } | |
187 | ||
188 | return IRQ_NONE; | |
189 | } | |
190 | ||
03ce758e | 191 | static int orion_mdio_probe(struct platform_device *pdev) |
fc8f5ade | 192 | { |
7111b717 | 193 | struct resource *r; |
fc8f5ade TP |
194 | struct mii_bus *bus; |
195 | struct orion_mdio_dev *dev; | |
196 | int i, ret; | |
197 | ||
7111b717 FF |
198 | r = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
199 | if (!r) { | |
200 | dev_err(&pdev->dev, "No SMI register address given\n"); | |
201 | return -ENODEV; | |
202 | } | |
203 | ||
fc8f5ade TP |
204 | bus = mdiobus_alloc_size(sizeof(struct orion_mdio_dev)); |
205 | if (!bus) { | |
206 | dev_err(&pdev->dev, "Cannot allocate MDIO bus\n"); | |
207 | return -ENOMEM; | |
208 | } | |
209 | ||
210 | bus->name = "orion_mdio_bus"; | |
211 | bus->read = orion_mdio_read; | |
212 | bus->write = orion_mdio_write; | |
213 | bus->reset = orion_mdio_reset; | |
214 | snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", | |
215 | dev_name(&pdev->dev)); | |
216 | bus->parent = &pdev->dev; | |
217 | ||
218 | bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL); | |
219 | if (!bus->irq) { | |
fc8f5ade TP |
220 | mdiobus_free(bus); |
221 | return -ENOMEM; | |
222 | } | |
223 | ||
224 | for (i = 0; i < PHY_MAX_ADDR; i++) | |
225 | bus->irq[i] = PHY_POLL; | |
226 | ||
227 | dev = bus->priv; | |
3712b717 FF |
228 | dev->regs = devm_ioremap(&pdev->dev, r->start, resource_size(r)); |
229 | if (!dev->regs) { | |
7111b717 | 230 | dev_err(&pdev->dev, "Unable to remap SMI register\n"); |
2ec98521 FF |
231 | ret = -ENODEV; |
232 | goto out_mdio; | |
233 | } | |
234 | ||
235 | init_waitqueue_head(&dev->smi_busy_wait); | |
236 | ||
3d604da1 SH |
237 | dev->clk = devm_clk_get(&pdev->dev, NULL); |
238 | if (!IS_ERR(dev->clk)) | |
239 | clk_prepare_enable(dev->clk); | |
240 | ||
2ec98521 FF |
241 | dev->err_interrupt = platform_get_irq(pdev, 0); |
242 | if (dev->err_interrupt != -ENXIO) { | |
243 | ret = devm_request_irq(&pdev->dev, dev->err_interrupt, | |
244 | orion_mdio_err_irq, | |
245 | IRQF_SHARED, pdev->name, dev); | |
246 | if (ret) | |
247 | goto out_mdio; | |
248 | ||
249 | writel(MVMDIO_ERR_INT_SMI_DONE, | |
250 | dev->regs + MVMDIO_ERR_INT_MASK); | |
fc8f5ade TP |
251 | } |
252 | ||
253 | mutex_init(&dev->lock); | |
254 | ||
7111b717 FF |
255 | if (pdev->dev.of_node) |
256 | ret = of_mdiobus_register(bus, pdev->dev.of_node); | |
257 | else | |
258 | ret = mdiobus_register(bus); | |
fc8f5ade TP |
259 | if (ret < 0) { |
260 | dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret); | |
2ec98521 | 261 | goto out_mdio; |
fc8f5ade TP |
262 | } |
263 | ||
264 | platform_set_drvdata(pdev, bus); | |
265 | ||
266 | return 0; | |
2ec98521 FF |
267 | |
268 | out_mdio: | |
3d604da1 SH |
269 | if (!IS_ERR(dev->clk)) |
270 | clk_disable_unprepare(dev->clk); | |
2ec98521 FF |
271 | kfree(bus->irq); |
272 | mdiobus_free(bus); | |
273 | return ret; | |
fc8f5ade TP |
274 | } |
275 | ||
03ce758e | 276 | static int orion_mdio_remove(struct platform_device *pdev) |
fc8f5ade TP |
277 | { |
278 | struct mii_bus *bus = platform_get_drvdata(pdev); | |
2ec98521 FF |
279 | struct orion_mdio_dev *dev = bus->priv; |
280 | ||
281 | writel(0, dev->regs + MVMDIO_ERR_INT_MASK); | |
fc8f5ade TP |
282 | mdiobus_unregister(bus); |
283 | kfree(bus->irq); | |
284 | mdiobus_free(bus); | |
3d604da1 SH |
285 | if (!IS_ERR(dev->clk)) |
286 | clk_disable_unprepare(dev->clk); | |
287 | ||
fc8f5ade TP |
288 | return 0; |
289 | } | |
290 | ||
291 | static const struct of_device_id orion_mdio_match[] = { | |
292 | { .compatible = "marvell,orion-mdio" }, | |
293 | { } | |
294 | }; | |
295 | MODULE_DEVICE_TABLE(of, orion_mdio_match); | |
296 | ||
297 | static struct platform_driver orion_mdio_driver = { | |
298 | .probe = orion_mdio_probe, | |
03ce758e | 299 | .remove = orion_mdio_remove, |
fc8f5ade TP |
300 | .driver = { |
301 | .name = "orion-mdio", | |
302 | .of_match_table = orion_mdio_match, | |
303 | }, | |
304 | }; | |
305 | ||
306 | module_platform_driver(orion_mdio_driver); | |
307 | ||
308 | MODULE_DESCRIPTION("Marvell MDIO interface driver"); | |
309 | MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>"); | |
310 | MODULE_LICENSE("GPL"); | |
404b8bed | 311 | MODULE_ALIAS("platform:orion-mdio"); |