Loading...
Note: File does not exist in v5.9.
1// SPDX-License-Identifier: (GPL-2.0 OR MIT)
2/*
3 * Driver for the MDIO interface of Microsemi network switches.
4 *
5 * Author: Alexandre Belloni <alexandre.belloni@bootlin.com>
6 * Copyright (c) 2017 Microsemi Corporation
7 */
8
9#include <linux/bitops.h>
10#include <linux/clk.h>
11#include <linux/io.h>
12#include <linux/iopoll.h>
13#include <linux/kernel.h>
14#include <linux/mdio/mdio-mscc-miim.h>
15#include <linux/mfd/ocelot.h>
16#include <linux/module.h>
17#include <linux/of_mdio.h>
18#include <linux/phy.h>
19#include <linux/platform_device.h>
20#include <linux/property.h>
21#include <linux/regmap.h>
22
23#define MSCC_MIIM_REG_STATUS 0x0
24#define MSCC_MIIM_STATUS_STAT_PENDING BIT(2)
25#define MSCC_MIIM_STATUS_STAT_BUSY BIT(3)
26#define MSCC_MIIM_REG_CMD 0x8
27#define MSCC_MIIM_CMD_OPR_WRITE BIT(1)
28#define MSCC_MIIM_CMD_OPR_READ BIT(2)
29#define MSCC_MIIM_CMD_WRDATA_SHIFT 4
30#define MSCC_MIIM_CMD_REGAD_SHIFT 20
31#define MSCC_MIIM_CMD_PHYAD_SHIFT 25
32#define MSCC_MIIM_CMD_VLD BIT(31)
33#define MSCC_MIIM_REG_DATA 0xC
34#define MSCC_MIIM_DATA_ERROR (BIT(16) | BIT(17))
35#define MSCC_MIIM_REG_CFG 0x10
36#define MSCC_MIIM_CFG_PRESCALE_MASK GENMASK(7, 0)
37
38#define MSCC_PHY_REG_PHY_CFG 0x0
39#define PHY_CFG_PHY_ENA (BIT(0) | BIT(1) | BIT(2) | BIT(3))
40#define PHY_CFG_PHY_COMMON_RESET BIT(4)
41#define PHY_CFG_PHY_RESET (BIT(5) | BIT(6) | BIT(7) | BIT(8))
42#define MSCC_PHY_REG_PHY_STATUS 0x4
43
44#define LAN966X_CUPHY_COMMON_CFG 0x0
45#define CUPHY_COMMON_CFG_RESET_N BIT(0)
46
47struct mscc_miim_info {
48 unsigned int phy_reset_offset;
49 unsigned int phy_reset_bits;
50};
51
52struct mscc_miim_dev {
53 struct regmap *regs;
54 int mii_status_offset;
55 bool ignore_read_errors;
56 struct regmap *phy_regs;
57 const struct mscc_miim_info *info;
58 struct clk *clk;
59 u32 bus_freq;
60};
61
62/* When high resolution timers aren't built-in: we can't use usleep_range() as
63 * we would sleep way too long. Use udelay() instead.
64 */
65#define mscc_readx_poll_timeout(op, addr, val, cond, delay_us, timeout_us)\
66({ \
67 if (!IS_ENABLED(CONFIG_HIGH_RES_TIMERS)) \
68 readx_poll_timeout_atomic(op, addr, val, cond, delay_us, \
69 timeout_us); \
70 readx_poll_timeout(op, addr, val, cond, delay_us, timeout_us); \
71})
72
73static int mscc_miim_status(struct mii_bus *bus)
74{
75 struct mscc_miim_dev *miim = bus->priv;
76 int val, ret;
77
78 ret = regmap_read(miim->regs,
79 MSCC_MIIM_REG_STATUS + miim->mii_status_offset, &val);
80 if (ret < 0) {
81 WARN_ONCE(1, "mscc miim status read error %d\n", ret);
82 return ret;
83 }
84
85 return val;
86}
87
88static int mscc_miim_wait_ready(struct mii_bus *bus)
89{
90 u32 val;
91
92 return mscc_readx_poll_timeout(mscc_miim_status, bus, val,
93 !(val & MSCC_MIIM_STATUS_STAT_BUSY), 50,
94 10000);
95}
96
97static int mscc_miim_wait_pending(struct mii_bus *bus)
98{
99 u32 val;
100
101 return mscc_readx_poll_timeout(mscc_miim_status, bus, val,
102 !(val & MSCC_MIIM_STATUS_STAT_PENDING),
103 50, 10000);
104}
105
106static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum)
107{
108 struct mscc_miim_dev *miim = bus->priv;
109 u32 val;
110 int ret;
111
112 ret = mscc_miim_wait_pending(bus);
113 if (ret)
114 goto out;
115
116 ret = regmap_write(miim->regs,
117 MSCC_MIIM_REG_CMD + miim->mii_status_offset,
118 MSCC_MIIM_CMD_VLD |
119 (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
120 (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
121 MSCC_MIIM_CMD_OPR_READ);
122
123 if (ret < 0) {
124 WARN_ONCE(1, "mscc miim write cmd reg error %d\n", ret);
125 goto out;
126 }
127
128 ret = mscc_miim_wait_ready(bus);
129 if (ret)
130 goto out;
131
132 ret = regmap_read(miim->regs,
133 MSCC_MIIM_REG_DATA + miim->mii_status_offset, &val);
134 if (ret < 0) {
135 WARN_ONCE(1, "mscc miim read data reg error %d\n", ret);
136 goto out;
137 }
138
139 if (!miim->ignore_read_errors && !!(val & MSCC_MIIM_DATA_ERROR)) {
140 ret = -EIO;
141 goto out;
142 }
143
144 ret = val & 0xFFFF;
145out:
146 return ret;
147}
148
149static int mscc_miim_write(struct mii_bus *bus, int mii_id,
150 int regnum, u16 value)
151{
152 struct mscc_miim_dev *miim = bus->priv;
153 int ret;
154
155 ret = mscc_miim_wait_pending(bus);
156 if (ret < 0)
157 goto out;
158
159 ret = regmap_write(miim->regs,
160 MSCC_MIIM_REG_CMD + miim->mii_status_offset,
161 MSCC_MIIM_CMD_VLD |
162 (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
163 (regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
164 (value << MSCC_MIIM_CMD_WRDATA_SHIFT) |
165 MSCC_MIIM_CMD_OPR_WRITE);
166
167 if (ret < 0)
168 WARN_ONCE(1, "mscc miim write error %d\n", ret);
169out:
170 return ret;
171}
172
173static int mscc_miim_reset(struct mii_bus *bus)
174{
175 struct mscc_miim_dev *miim = bus->priv;
176 unsigned int offset, bits;
177 int ret;
178
179 if (!miim->phy_regs)
180 return 0;
181
182 offset = miim->info->phy_reset_offset;
183 bits = miim->info->phy_reset_bits;
184
185 ret = regmap_update_bits(miim->phy_regs, offset, bits, 0);
186 if (ret < 0) {
187 WARN_ONCE(1, "mscc reset set error %d\n", ret);
188 return ret;
189 }
190
191 ret = regmap_update_bits(miim->phy_regs, offset, bits, bits);
192 if (ret < 0) {
193 WARN_ONCE(1, "mscc reset clear error %d\n", ret);
194 return ret;
195 }
196
197 mdelay(500);
198
199 return 0;
200}
201
202static const struct regmap_config mscc_miim_regmap_config = {
203 .reg_bits = 32,
204 .val_bits = 32,
205 .reg_stride = 4,
206};
207
208static const struct regmap_config mscc_miim_phy_regmap_config = {
209 .reg_bits = 32,
210 .val_bits = 32,
211 .reg_stride = 4,
212 .name = "phy",
213};
214
215int mscc_miim_setup(struct device *dev, struct mii_bus **pbus, const char *name,
216 struct regmap *mii_regmap, int status_offset,
217 bool ignore_read_errors)
218{
219 struct mscc_miim_dev *miim;
220 struct mii_bus *bus;
221
222 bus = devm_mdiobus_alloc_size(dev, sizeof(*miim));
223 if (!bus)
224 return -ENOMEM;
225
226 bus->name = name;
227 bus->read = mscc_miim_read;
228 bus->write = mscc_miim_write;
229 bus->reset = mscc_miim_reset;
230 snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(dev));
231 bus->parent = dev;
232
233 miim = bus->priv;
234
235 *pbus = bus;
236
237 miim->regs = mii_regmap;
238 miim->mii_status_offset = status_offset;
239 miim->ignore_read_errors = ignore_read_errors;
240
241 *pbus = bus;
242
243 return 0;
244}
245EXPORT_SYMBOL(mscc_miim_setup);
246
247static int mscc_miim_clk_set(struct mii_bus *bus)
248{
249 struct mscc_miim_dev *miim = bus->priv;
250 unsigned long rate;
251 u32 div;
252
253 /* Keep the current settings */
254 if (!miim->bus_freq)
255 return 0;
256
257 rate = clk_get_rate(miim->clk);
258
259 div = DIV_ROUND_UP(rate, 2 * miim->bus_freq) - 1;
260 if (div == 0 || div & ~MSCC_MIIM_CFG_PRESCALE_MASK) {
261 dev_err(&bus->dev, "Incorrect MDIO clock frequency\n");
262 return -EINVAL;
263 }
264
265 return regmap_update_bits(miim->regs, MSCC_MIIM_REG_CFG,
266 MSCC_MIIM_CFG_PRESCALE_MASK, div);
267}
268
269static int mscc_miim_probe(struct platform_device *pdev)
270{
271 struct device_node *np = pdev->dev.of_node;
272 struct regmap *mii_regmap, *phy_regmap;
273 struct device *dev = &pdev->dev;
274 struct mscc_miim_dev *miim;
275 struct mii_bus *bus;
276 int ret;
277
278 mii_regmap = ocelot_regmap_from_resource(pdev, 0,
279 &mscc_miim_regmap_config);
280 if (IS_ERR(mii_regmap))
281 return dev_err_probe(dev, PTR_ERR(mii_regmap),
282 "Unable to create MIIM regmap\n");
283
284 /* This resource is optional */
285 phy_regmap = ocelot_regmap_from_resource_optional(pdev, 1,
286 &mscc_miim_phy_regmap_config);
287 if (IS_ERR(phy_regmap))
288 return dev_err_probe(dev, PTR_ERR(phy_regmap),
289 "Unable to create phy register regmap\n");
290
291 ret = mscc_miim_setup(dev, &bus, "mscc_miim", mii_regmap, 0, false);
292 if (ret < 0) {
293 dev_err(dev, "Unable to setup the MDIO bus\n");
294 return ret;
295 }
296
297 miim = bus->priv;
298 miim->phy_regs = phy_regmap;
299
300 miim->info = device_get_match_data(dev);
301 if (!miim->info)
302 return -EINVAL;
303
304 miim->clk = devm_clk_get_optional(dev, NULL);
305 if (IS_ERR(miim->clk))
306 return PTR_ERR(miim->clk);
307
308 of_property_read_u32(np, "clock-frequency", &miim->bus_freq);
309
310 if (miim->bus_freq && !miim->clk) {
311 dev_err(dev, "cannot use clock-frequency without a clock\n");
312 return -EINVAL;
313 }
314
315 ret = clk_prepare_enable(miim->clk);
316 if (ret)
317 return ret;
318
319 ret = mscc_miim_clk_set(bus);
320 if (ret)
321 goto out_disable_clk;
322
323 ret = of_mdiobus_register(bus, np);
324 if (ret < 0) {
325 dev_err(dev, "Cannot register MDIO bus (%d)\n", ret);
326 goto out_disable_clk;
327 }
328
329 platform_set_drvdata(pdev, bus);
330
331 return 0;
332
333out_disable_clk:
334 clk_disable_unprepare(miim->clk);
335 return ret;
336}
337
338static void mscc_miim_remove(struct platform_device *pdev)
339{
340 struct mii_bus *bus = platform_get_drvdata(pdev);
341 struct mscc_miim_dev *miim = bus->priv;
342
343 clk_disable_unprepare(miim->clk);
344 mdiobus_unregister(bus);
345}
346
347static const struct mscc_miim_info mscc_ocelot_miim_info = {
348 .phy_reset_offset = MSCC_PHY_REG_PHY_CFG,
349 .phy_reset_bits = PHY_CFG_PHY_ENA | PHY_CFG_PHY_COMMON_RESET |
350 PHY_CFG_PHY_RESET,
351};
352
353static const struct mscc_miim_info microchip_lan966x_miim_info = {
354 .phy_reset_offset = LAN966X_CUPHY_COMMON_CFG,
355 .phy_reset_bits = CUPHY_COMMON_CFG_RESET_N,
356};
357
358static const struct of_device_id mscc_miim_match[] = {
359 {
360 .compatible = "mscc,ocelot-miim",
361 .data = &mscc_ocelot_miim_info
362 }, {
363 .compatible = "microchip,lan966x-miim",
364 .data = µchip_lan966x_miim_info
365 },
366 { }
367};
368MODULE_DEVICE_TABLE(of, mscc_miim_match);
369
370static struct platform_driver mscc_miim_driver = {
371 .probe = mscc_miim_probe,
372 .remove_new = mscc_miim_remove,
373 .driver = {
374 .name = "mscc-miim",
375 .of_match_table = mscc_miim_match,
376 },
377};
378
379module_platform_driver(mscc_miim_driver);
380
381MODULE_DESCRIPTION("Microsemi MIIM driver");
382MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
383MODULE_LICENSE("Dual MIT/GPL");