1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Amlogic G12A USB3 + PCIE Combo PHY driver
4  *
5  * Copyright (C) 2017 Amlogic, Inc. All rights reserved
6  * Copyright (C) 2019 BayLibre, SAS
7  * Author: Neil Armstrong <narmstrong@baylibre.com>
8  */
9 
10 #include <linux/bitfield.h>
11 #include <linux/bitops.h>
12 #include <linux/clk.h>
13 #include <linux/module.h>
14 #include <linux/of_device.h>
15 #include <linux/phy/phy.h>
16 #include <linux/regmap.h>
17 #include <linux/reset.h>
18 #include <linux/platform_device.h>
19 #include <dt-bindings/phy/phy.h>
20 
21 #define PHY_R0							0x00
22 	#define PHY_R0_PCIE_POWER_STATE				GENMASK(4, 0)
23 	#define PHY_R0_PCIE_USB3_SWITCH				GENMASK(6, 5)
24 
25 #define PHY_R1							0x04
26 	#define PHY_R1_PHY_TX1_TERM_OFFSET			GENMASK(4, 0)
27 	#define PHY_R1_PHY_TX0_TERM_OFFSET			GENMASK(9, 5)
28 	#define PHY_R1_PHY_RX1_EQ				GENMASK(12, 10)
29 	#define PHY_R1_PHY_RX0_EQ				GENMASK(15, 13)
30 	#define PHY_R1_PHY_LOS_LEVEL				GENMASK(20, 16)
31 	#define PHY_R1_PHY_LOS_BIAS				GENMASK(23, 21)
32 	#define PHY_R1_PHY_REF_CLKDIV2				BIT(24)
33 	#define PHY_R1_PHY_MPLL_MULTIPLIER			GENMASK(31, 25)
34 
35 #define PHY_R2							0x08
36 	#define PHY_R2_PCS_TX_DEEMPH_GEN2_6DB			GENMASK(5, 0)
37 	#define PHY_R2_PCS_TX_DEEMPH_GEN2_3P5DB			GENMASK(11, 6)
38 	#define PHY_R2_PCS_TX_DEEMPH_GEN1			GENMASK(17, 12)
39 	#define PHY_R2_PHY_TX_VBOOST_LVL			GENMASK(20, 18)
40 
41 #define PHY_R4							0x10
42 	#define PHY_R4_PHY_CR_WRITE				BIT(0)
43 	#define PHY_R4_PHY_CR_READ				BIT(1)
44 	#define PHY_R4_PHY_CR_DATA_IN				GENMASK(17, 2)
45 	#define PHY_R4_PHY_CR_CAP_DATA				BIT(18)
46 	#define PHY_R4_PHY_CR_CAP_ADDR				BIT(19)
47 
48 #define PHY_R5							0x14
49 	#define PHY_R5_PHY_CR_DATA_OUT				GENMASK(15, 0)
50 	#define PHY_R5_PHY_CR_ACK				BIT(16)
51 	#define PHY_R5_PHY_BS_OUT				BIT(17)
52 
53 #define PCIE_RESET_DELAY					500
54 
55 struct phy_g12a_usb3_pcie_priv {
56 	struct regmap		*regmap;
57 	struct regmap		*regmap_cr;
58 	struct clk		*clk_ref;
59 	struct reset_control	*reset;
60 	struct phy		*phy;
61 	unsigned int		mode;
62 };
63 
64 static const struct regmap_config phy_g12a_usb3_pcie_regmap_conf = {
65 	.reg_bits = 8,
66 	.val_bits = 32,
67 	.reg_stride = 4,
68 	.max_register = PHY_R5,
69 };
70 
71 static int phy_g12a_usb3_pcie_cr_bus_addr(struct phy_g12a_usb3_pcie_priv *priv,
72 					  unsigned int addr)
73 {
74 	unsigned int val, reg;
75 	int ret;
76 
77 	reg = FIELD_PREP(PHY_R4_PHY_CR_DATA_IN, addr);
78 
79 	regmap_write(priv->regmap, PHY_R4, reg);
80 	regmap_write(priv->regmap, PHY_R4, reg);
81 
82 	regmap_write(priv->regmap, PHY_R4, reg | PHY_R4_PHY_CR_CAP_ADDR);
83 
84 	ret = regmap_read_poll_timeout(priv->regmap, PHY_R5, val,
85 				       (val & PHY_R5_PHY_CR_ACK),
86 				       5, 1000);
87 	if (ret)
88 		return ret;
89 
90 	regmap_write(priv->regmap, PHY_R4, reg);
91 
92 	ret = regmap_read_poll_timeout(priv->regmap, PHY_R5, val,
93 				       !(val & PHY_R5_PHY_CR_ACK),
94 				       5, 1000);
95 	if (ret)
96 		return ret;
97 
98 	return 0;
99 }
100 
101 static int phy_g12a_usb3_pcie_cr_bus_read(void *context, unsigned int addr,
102 					  unsigned int *data)
103 {
104 	struct phy_g12a_usb3_pcie_priv *priv = context;
105 	unsigned int val;
106 	int ret;
107 
108 	ret = phy_g12a_usb3_pcie_cr_bus_addr(priv, addr);
109 	if (ret)
110 		return ret;
111 
112 	regmap_write(priv->regmap, PHY_R4, 0);
113 	regmap_write(priv->regmap, PHY_R4, PHY_R4_PHY_CR_READ);
114 
115 	ret = regmap_read_poll_timeout(priv->regmap, PHY_R5, val,
116 				       (val & PHY_R5_PHY_CR_ACK),
117 				       5, 1000);
118 	if (ret)
119 		return ret;
120 
121 	*data = FIELD_GET(PHY_R5_PHY_CR_DATA_OUT, val);
122 
123 	regmap_write(priv->regmap, PHY_R4, 0);
124 
125 	ret = regmap_read_poll_timeout(priv->regmap, PHY_R5, val,
126 				       !(val & PHY_R5_PHY_CR_ACK),
127 				       5, 1000);
128 	if (ret)
129 		return ret;
130 
131 	return 0;
132 }
133 
134 static int phy_g12a_usb3_pcie_cr_bus_write(void *context, unsigned int addr,
135 					   unsigned int data)
136 {
137 	struct phy_g12a_usb3_pcie_priv *priv = context;
138 	unsigned int val, reg;
139 	int ret;
140 
141 	ret = phy_g12a_usb3_pcie_cr_bus_addr(priv, addr);
142 	if (ret)
143 		return ret;
144 
145 	reg = FIELD_PREP(PHY_R4_PHY_CR_DATA_IN, data);
146 
147 	regmap_write(priv->regmap, PHY_R4, reg);
148 	regmap_write(priv->regmap, PHY_R4, reg);
149 
150 	regmap_write(priv->regmap, PHY_R4, reg | PHY_R4_PHY_CR_CAP_DATA);
151 
152 	ret = regmap_read_poll_timeout(priv->regmap, PHY_R5, val,
153 				       (val & PHY_R5_PHY_CR_ACK),
154 				       5, 1000);
155 	if (ret)
156 		return ret;
157 
158 	regmap_write(priv->regmap, PHY_R4, reg);
159 
160 	ret = regmap_read_poll_timeout(priv->regmap, PHY_R5, val,
161 				       (val & PHY_R5_PHY_CR_ACK) == 0,
162 				       5, 1000);
163 	if (ret)
164 		return ret;
165 
166 	regmap_write(priv->regmap, PHY_R4, reg);
167 
168 	regmap_write(priv->regmap, PHY_R4, reg | PHY_R4_PHY_CR_WRITE);
169 
170 	ret = regmap_read_poll_timeout(priv->regmap, PHY_R5, val,
171 				       (val & PHY_R5_PHY_CR_ACK),
172 				       5, 1000);
173 	if (ret)
174 		return ret;
175 
176 	regmap_write(priv->regmap, PHY_R4, reg);
177 
178 	ret = regmap_read_poll_timeout(priv->regmap, PHY_R5, val,
179 				       (val & PHY_R5_PHY_CR_ACK) == 0,
180 				       5, 1000);
181 	if (ret)
182 		return ret;
183 
184 	return 0;
185 }
186 
187 static const struct regmap_config phy_g12a_usb3_pcie_cr_regmap_conf = {
188 	.reg_bits = 16,
189 	.val_bits = 16,
190 	.reg_read = phy_g12a_usb3_pcie_cr_bus_read,
191 	.reg_write = phy_g12a_usb3_pcie_cr_bus_write,
192 	.max_register = 0xffff,
193 	.disable_locking = true,
194 };
195 
196 static int phy_g12a_usb3_init(struct phy *phy)
197 {
198 	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
199 	int data, ret;
200 
201 	ret = reset_control_reset(priv->reset);
202 	if (ret)
203 		return ret;
204 
205 	/* Switch PHY to USB3 */
206 	/* TODO figure out how to handle when PCIe was set in the bootloader */
207 	regmap_update_bits(priv->regmap, PHY_R0,
208 			   PHY_R0_PCIE_USB3_SWITCH,
209 			   PHY_R0_PCIE_USB3_SWITCH);
210 
211 	/*
212 	 * WORKAROUND: There is SSPHY suspend bug due to
213 	 * which USB enumerates
214 	 * in HS mode instead of SS mode. Workaround it by asserting
215 	 * LANE0.TX_ALT_BLOCK.EN_ALT_BUS to enable TX to use alt bus
216 	 * mode
217 	 */
218 	ret = regmap_update_bits(priv->regmap_cr, 0x102d, BIT(7), BIT(7));
219 	if (ret)
220 		return ret;
221 
222 	ret = regmap_update_bits(priv->regmap_cr, 0x1010, 0xff0, 20);
223 	if (ret)
224 		return ret;
225 
226 	/*
227 	 * Fix RX Equalization setting as follows
228 	 * LANE0.RX_OVRD_IN_HI. RX_EQ_EN set to 0
229 	 * LANE0.RX_OVRD_IN_HI.RX_EQ_EN_OVRD set to 1
230 	 * LANE0.RX_OVRD_IN_HI.RX_EQ set to 3
231 	 * LANE0.RX_OVRD_IN_HI.RX_EQ_OVRD set to 1
232 	 */
233 	ret = regmap_read(priv->regmap_cr, 0x1006, &data);
234 	if (ret)
235 		return ret;
236 
237 	data &= ~BIT(6);
238 	data |= BIT(7);
239 	data &= ~(0x7 << 8);
240 	data |= (0x3 << 8);
241 	data |= (1 << 11);
242 	ret = regmap_write(priv->regmap_cr, 0x1006, data);
243 	if (ret)
244 		return ret;
245 
246 	/*
247 	 * Set EQ and TX launch amplitudes as follows
248 	 * LANE0.TX_OVRD_DRV_LO.PREEMPH set to 22
249 	 * LANE0.TX_OVRD_DRV_LO.AMPLITUDE set to 127
250 	 * LANE0.TX_OVRD_DRV_LO.EN set to 1.
251 	 */
252 	ret = regmap_read(priv->regmap_cr, 0x1002, &data);
253 	if (ret)
254 		return ret;
255 
256 	data &= ~0x3f80;
257 	data |= (0x16 << 7);
258 	data &= ~0x7f;
259 	data |= (0x7f | BIT(14));
260 	ret = regmap_write(priv->regmap_cr, 0x1002, data);
261 	if (ret)
262 		return ret;
263 
264 	/* MPLL_LOOP_CTL.PROP_CNTRL = 8 */
265 	ret = regmap_update_bits(priv->regmap_cr, 0x30, 0xf << 4, 8 << 4);
266 	if (ret)
267 		return ret;
268 
269 	regmap_update_bits(priv->regmap, PHY_R2,
270 			PHY_R2_PHY_TX_VBOOST_LVL,
271 			FIELD_PREP(PHY_R2_PHY_TX_VBOOST_LVL, 0x4));
272 
273 	regmap_update_bits(priv->regmap, PHY_R1,
274 			PHY_R1_PHY_LOS_BIAS | PHY_R1_PHY_LOS_LEVEL,
275 			FIELD_PREP(PHY_R1_PHY_LOS_BIAS, 4) |
276 			FIELD_PREP(PHY_R1_PHY_LOS_LEVEL, 9));
277 
278 	return 0;
279 }
280 
281 static int phy_g12a_usb3_pcie_power_on(struct phy *phy)
282 {
283 	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
284 
285 	if (priv->mode == PHY_TYPE_USB3)
286 		return 0;
287 
288 	regmap_update_bits(priv->regmap, PHY_R0,
289 			   PHY_R0_PCIE_POWER_STATE,
290 			   FIELD_PREP(PHY_R0_PCIE_POWER_STATE, 0x1c));
291 
292 	return 0;
293 }
294 
295 static int phy_g12a_usb3_pcie_power_off(struct phy *phy)
296 {
297 	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
298 
299 	if (priv->mode == PHY_TYPE_USB3)
300 		return 0;
301 
302 	regmap_update_bits(priv->regmap, PHY_R0,
303 			   PHY_R0_PCIE_POWER_STATE,
304 			   FIELD_PREP(PHY_R0_PCIE_POWER_STATE, 0x1d));
305 
306 	return 0;
307 }
308 
309 static int phy_g12a_usb3_pcie_reset(struct phy *phy)
310 {
311 	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
312 	int ret;
313 
314 	if (priv->mode == PHY_TYPE_USB3)
315 		return 0;
316 
317 	ret = reset_control_assert(priv->reset);
318 	if (ret)
319 		return ret;
320 
321 	udelay(PCIE_RESET_DELAY);
322 
323 	ret = reset_control_deassert(priv->reset);
324 	if (ret)
325 		return ret;
326 
327 	udelay(PCIE_RESET_DELAY);
328 
329 	return 0;
330 }
331 
332 static int phy_g12a_usb3_pcie_init(struct phy *phy)
333 {
334 	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
335 
336 	if (priv->mode == PHY_TYPE_USB3)
337 		return phy_g12a_usb3_init(phy);
338 
339 	return 0;
340 }
341 
342 static int phy_g12a_usb3_pcie_exit(struct phy *phy)
343 {
344 	struct phy_g12a_usb3_pcie_priv *priv = phy_get_drvdata(phy);
345 
346 	if (priv->mode == PHY_TYPE_USB3)
347 		return reset_control_reset(priv->reset);
348 
349 	return 0;
350 }
351 
352 static struct phy *phy_g12a_usb3_pcie_xlate(struct device *dev,
353 					    struct of_phandle_args *args)
354 {
355 	struct phy_g12a_usb3_pcie_priv *priv = dev_get_drvdata(dev);
356 	unsigned int mode;
357 
358 	if (args->args_count < 1) {
359 		dev_err(dev, "invalid number of arguments\n");
360 		return ERR_PTR(-EINVAL);
361 	}
362 
363 	mode = args->args[0];
364 
365 	if (mode != PHY_TYPE_USB3 && mode != PHY_TYPE_PCIE) {
366 		dev_err(dev, "invalid phy mode select argument\n");
367 		return ERR_PTR(-EINVAL);
368 	}
369 
370 	priv->mode = mode;
371 
372 	return priv->phy;
373 }
374 
375 static const struct phy_ops phy_g12a_usb3_pcie_ops = {
376 	.init		= phy_g12a_usb3_pcie_init,
377 	.exit		= phy_g12a_usb3_pcie_exit,
378 	.power_on	= phy_g12a_usb3_pcie_power_on,
379 	.power_off	= phy_g12a_usb3_pcie_power_off,
380 	.reset		= phy_g12a_usb3_pcie_reset,
381 	.owner		= THIS_MODULE,
382 };
383 
384 static int phy_g12a_usb3_pcie_probe(struct platform_device *pdev)
385 {
386 	struct device *dev = &pdev->dev;
387 	struct device_node *np = dev->of_node;
388 	struct phy_g12a_usb3_pcie_priv *priv;
389 	struct resource *res;
390 	struct phy_provider *phy_provider;
391 	void __iomem *base;
392 	int ret;
393 
394 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
395 	if (!priv)
396 		return -ENOMEM;
397 
398 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
399 	base = devm_ioremap_resource(dev, res);
400 	if (IS_ERR(base))
401 		return PTR_ERR(base);
402 
403 	priv->regmap = devm_regmap_init_mmio(dev, base,
404 					     &phy_g12a_usb3_pcie_regmap_conf);
405 	if (IS_ERR(priv->regmap))
406 		return PTR_ERR(priv->regmap);
407 
408 	priv->regmap_cr = devm_regmap_init(dev, NULL, priv,
409 					   &phy_g12a_usb3_pcie_cr_regmap_conf);
410 	if (IS_ERR(priv->regmap_cr))
411 		return PTR_ERR(priv->regmap_cr);
412 
413 	priv->clk_ref = devm_clk_get(dev, "ref_clk");
414 	if (IS_ERR(priv->clk_ref))
415 		return PTR_ERR(priv->clk_ref);
416 
417 	ret = clk_prepare_enable(priv->clk_ref);
418 	if (ret)
419 		goto err_disable_clk_ref;
420 
421 	priv->reset = devm_reset_control_array_get(dev, false, false);
422 	if (IS_ERR(priv->reset))
423 		return PTR_ERR(priv->reset);
424 
425 	priv->phy = devm_phy_create(dev, np, &phy_g12a_usb3_pcie_ops);
426 	if (IS_ERR(priv->phy)) {
427 		ret = PTR_ERR(priv->phy);
428 		if (ret != -EPROBE_DEFER)
429 			dev_err(dev, "failed to create PHY\n");
430 
431 		return ret;
432 	}
433 
434 	phy_set_drvdata(priv->phy, priv);
435 	dev_set_drvdata(dev, priv);
436 
437 	phy_provider = devm_of_phy_provider_register(dev,
438 						     phy_g12a_usb3_pcie_xlate);
439 
440 	return PTR_ERR_OR_ZERO(phy_provider);
441 
442 err_disable_clk_ref:
443 	clk_disable_unprepare(priv->clk_ref);
444 
445 	return ret;
446 }
447 
448 static const struct of_device_id phy_g12a_usb3_pcie_of_match[] = {
449 	{ .compatible = "amlogic,g12a-usb3-pcie-phy", },
450 	{ },
451 };
452 MODULE_DEVICE_TABLE(of, phy_g12a_usb3_pcie_of_match);
453 
454 static struct platform_driver phy_g12a_usb3_pcie_driver = {
455 	.probe	= phy_g12a_usb3_pcie_probe,
456 	.driver	= {
457 		.name		= "phy-g12a-usb3-pcie",
458 		.of_match_table	= phy_g12a_usb3_pcie_of_match,
459 	},
460 };
461 module_platform_driver(phy_g12a_usb3_pcie_driver);
462 
463 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
464 MODULE_DESCRIPTION("Amlogic G12A USB3 + PCIE Combo PHY driver");
465 MODULE_LICENSE("GPL v2");
466