xref: /linux/drivers/reset/reset-npcm.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2019 Nuvoton Technology corporation.
3 
4 #include <linux/auxiliary_bus.h>
5 #include <linux/delay.h>
6 #include <linux/err.h>
7 #include <linux/io.h>
8 #include <linux/init.h>
9 #include <linux/of.h>
10 #include <linux/platform_device.h>
11 #include <linux/property.h>
12 #include <linux/reboot.h>
13 #include <linux/reset-controller.h>
14 #include <linux/slab.h>
15 #include <linux/spinlock.h>
16 #include <linux/mfd/syscon.h>
17 #include <linux/regmap.h>
18 #include <linux/of_address.h>
19 
20 #include <soc/nuvoton/clock-npcm8xx.h>
21 
22 /* NPCM7xx GCR registers */
23 #define NPCM_MDLR_OFFSET	0x7C
24 #define NPCM7XX_MDLR_USBD0	BIT(9)
25 #define NPCM7XX_MDLR_USBD1	BIT(8)
26 #define NPCM7XX_MDLR_USBD2_4	BIT(21)
27 #define NPCM7XX_MDLR_USBD5_9	BIT(22)
28 
29 /* NPCM8xx MDLR bits */
30 #define NPCM8XX_MDLR_USBD0_3	BIT(9)
31 #define NPCM8XX_MDLR_USBD4_7	BIT(22)
32 #define NPCM8XX_MDLR_USBD8	BIT(24)
33 #define NPCM8XX_MDLR_USBD9	BIT(21)
34 
35 #define NPCM_USB1PHYCTL_OFFSET	0x140
36 #define NPCM_USB2PHYCTL_OFFSET	0x144
37 #define NPCM_USB3PHYCTL_OFFSET	0x148
38 #define NPCM_USBXPHYCTL_RS	BIT(28)
39 
40 /* NPCM7xx Reset registers */
41 #define NPCM_SWRSTR		0x14
42 #define NPCM_SWRST		BIT(2)
43 
44 #define NPCM_IPSRST1		0x20
45 #define NPCM_IPSRST1_USBD1	BIT(5)
46 #define NPCM_IPSRST1_USBD2	BIT(8)
47 #define NPCM_IPSRST1_USBD3	BIT(25)
48 #define NPCM_IPSRST1_USBD4	BIT(22)
49 #define NPCM_IPSRST1_USBD5	BIT(23)
50 #define NPCM_IPSRST1_USBD6	BIT(24)
51 
52 #define NPCM_IPSRST2		0x24
53 #define NPCM_IPSRST2_USB_HOST	BIT(26)
54 
55 #define NPCM_IPSRST3		0x34
56 #define NPCM_IPSRST3_USBD0	BIT(4)
57 #define NPCM_IPSRST3_USBD7	BIT(5)
58 #define NPCM_IPSRST3_USBD8	BIT(6)
59 #define NPCM_IPSRST3_USBD9	BIT(7)
60 #define NPCM_IPSRST3_USBPHY1	BIT(24)
61 #define NPCM_IPSRST3_USBPHY2	BIT(25)
62 
63 #define NPCM_IPSRST4		0x74
64 #define NPCM_IPSRST4_USBPHY3	BIT(25)
65 #define NPCM_IPSRST4_USB_HOST2	BIT(31)
66 
67 #define NPCM_RC_RESETS_PER_REG	32
68 #define NPCM_MASK_RESETS	GENMASK(4, 0)
69 
70 enum {
71 	BMC_NPCM7XX = 0,
72 	BMC_NPCM8XX,
73 };
74 
75 static const u32 npxm7xx_ipsrst[] = {NPCM_IPSRST1, NPCM_IPSRST2, NPCM_IPSRST3};
76 static const u32 npxm8xx_ipsrst[] = {NPCM_IPSRST1, NPCM_IPSRST2, NPCM_IPSRST3,
77 	NPCM_IPSRST4};
78 
79 struct npcm_reset_info {
80 	u32 bmc_id;
81 	u32 num_ipsrst;
82 	const u32 *ipsrst;
83 };
84 
85 static const struct npcm_reset_info npxm7xx_reset_info[] = {
86 	{.bmc_id = BMC_NPCM7XX, .num_ipsrst = 3, .ipsrst = npxm7xx_ipsrst}};
87 static const struct npcm_reset_info npxm8xx_reset_info[] = {
88 	{.bmc_id = BMC_NPCM8XX, .num_ipsrst = 4, .ipsrst = npxm8xx_ipsrst}};
89 
90 struct npcm_rc_data {
91 	struct reset_controller_dev rcdev;
92 	struct notifier_block restart_nb;
93 	const struct npcm_reset_info *info;
94 	struct regmap *gcr_regmap;
95 	u32 sw_reset_number;
96 	struct device *dev;
97 	void __iomem *base;
98 	spinlock_t lock;
99 };
100 
101 #define to_rc_data(p) container_of(p, struct npcm_rc_data, rcdev)
102 
103 static int npcm_rc_restart(struct notifier_block *nb, unsigned long mode,
104 			   void *cmd)
105 {
106 	struct npcm_rc_data *rc = container_of(nb, struct npcm_rc_data,
107 					       restart_nb);
108 
109 	writel(NPCM_SWRST << rc->sw_reset_number, rc->base + NPCM_SWRSTR);
110 	mdelay(1000);
111 
112 	pr_emerg("%s: unable to restart system\n", __func__);
113 
114 	return NOTIFY_DONE;
115 }
116 
117 static int npcm_rc_setclear_reset(struct reset_controller_dev *rcdev,
118 				  unsigned long id, bool set)
119 {
120 	struct npcm_rc_data *rc = to_rc_data(rcdev);
121 	unsigned int rst_bit = BIT(id & NPCM_MASK_RESETS);
122 	unsigned int ctrl_offset = id >> 8;
123 	unsigned long flags;
124 	u32 stat;
125 
126 	spin_lock_irqsave(&rc->lock, flags);
127 	stat = readl(rc->base + ctrl_offset);
128 	if (set)
129 		writel(stat | rst_bit, rc->base + ctrl_offset);
130 	else
131 		writel(stat & ~rst_bit, rc->base + ctrl_offset);
132 	spin_unlock_irqrestore(&rc->lock, flags);
133 
134 	return 0;
135 }
136 
137 static int npcm_rc_assert(struct reset_controller_dev *rcdev, unsigned long id)
138 {
139 	return npcm_rc_setclear_reset(rcdev, id, true);
140 }
141 
142 static int npcm_rc_deassert(struct reset_controller_dev *rcdev,
143 			    unsigned long id)
144 {
145 	return npcm_rc_setclear_reset(rcdev, id, false);
146 }
147 
148 static int npcm_rc_status(struct reset_controller_dev *rcdev,
149 			  unsigned long id)
150 {
151 	struct npcm_rc_data *rc = to_rc_data(rcdev);
152 	unsigned int rst_bit = BIT(id & NPCM_MASK_RESETS);
153 	unsigned int ctrl_offset = id >> 8;
154 
155 	return (readl(rc->base + ctrl_offset) & rst_bit);
156 }
157 
158 static int npcm_reset_xlate(struct reset_controller_dev *rcdev,
159 			    const struct of_phandle_args *reset_spec)
160 {
161 	struct npcm_rc_data *rc = to_rc_data(rcdev);
162 	unsigned int offset, bit;
163 	bool offset_found = false;
164 	int off_num;
165 
166 	offset = reset_spec->args[0];
167 	for (off_num = 0 ; off_num < rc->info->num_ipsrst ; off_num++) {
168 		if (offset == rc->info->ipsrst[off_num]) {
169 			offset_found = true;
170 			break;
171 		}
172 	}
173 
174 	if (!offset_found) {
175 		dev_err(rcdev->dev, "Error reset register (0x%x)\n", offset);
176 		return -EINVAL;
177 	}
178 
179 	bit = reset_spec->args[1];
180 	if (bit >= NPCM_RC_RESETS_PER_REG) {
181 		dev_err(rcdev->dev, "Error reset number (%d)\n", bit);
182 		return -EINVAL;
183 	}
184 
185 	return (offset << 8) | bit;
186 }
187 
188 static const struct of_device_id npcm_rc_match[] = {
189 	{ .compatible = "nuvoton,npcm750-reset", .data = &npxm7xx_reset_info},
190 	{ .compatible = "nuvoton,npcm845-reset", .data = &npxm8xx_reset_info},
191 	{ }
192 };
193 
194 static void npcm_usb_reset_npcm7xx(struct npcm_rc_data *rc)
195 {
196 	u32 mdlr, iprst1, iprst2, iprst3;
197 	u32 ipsrst1_bits = 0;
198 	u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST;
199 	u32 ipsrst3_bits = 0;
200 
201 	/* checking which USB device is enabled */
202 	regmap_read(rc->gcr_regmap, NPCM_MDLR_OFFSET, &mdlr);
203 	if (!(mdlr & NPCM7XX_MDLR_USBD0))
204 		ipsrst3_bits |= NPCM_IPSRST3_USBD0;
205 	if (!(mdlr & NPCM7XX_MDLR_USBD1))
206 		ipsrst1_bits |= NPCM_IPSRST1_USBD1;
207 	if (!(mdlr & NPCM7XX_MDLR_USBD2_4))
208 		ipsrst1_bits |= (NPCM_IPSRST1_USBD2 |
209 				 NPCM_IPSRST1_USBD3 |
210 				 NPCM_IPSRST1_USBD4);
211 	if (!(mdlr & NPCM7XX_MDLR_USBD0)) {
212 		ipsrst1_bits |= (NPCM_IPSRST1_USBD5 |
213 				 NPCM_IPSRST1_USBD6);
214 		ipsrst3_bits |= (NPCM_IPSRST3_USBD7 |
215 				 NPCM_IPSRST3_USBD8 |
216 				 NPCM_IPSRST3_USBD9);
217 	}
218 
219 	/* assert reset USB PHY and USB devices */
220 	iprst1 = readl(rc->base + NPCM_IPSRST1);
221 	iprst2 = readl(rc->base + NPCM_IPSRST2);
222 	iprst3 = readl(rc->base + NPCM_IPSRST3);
223 
224 	iprst1 |= ipsrst1_bits;
225 	iprst2 |= ipsrst2_bits;
226 	iprst3 |= (ipsrst3_bits | NPCM_IPSRST3_USBPHY1 |
227 		   NPCM_IPSRST3_USBPHY2);
228 
229 	writel(iprst1, rc->base + NPCM_IPSRST1);
230 	writel(iprst2, rc->base + NPCM_IPSRST2);
231 	writel(iprst3, rc->base + NPCM_IPSRST3);
232 
233 	/* clear USB PHY RS bit */
234 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
235 			   NPCM_USBXPHYCTL_RS, 0);
236 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
237 			   NPCM_USBXPHYCTL_RS, 0);
238 
239 	/* deassert reset USB PHY */
240 	iprst3 &= ~(NPCM_IPSRST3_USBPHY1 | NPCM_IPSRST3_USBPHY2);
241 	writel(iprst3, rc->base + NPCM_IPSRST3);
242 
243 	udelay(50);
244 
245 	/* set USB PHY RS bit */
246 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
247 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
248 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
249 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
250 
251 	/* deassert reset USB devices*/
252 	iprst1 &= ~ipsrst1_bits;
253 	iprst2 &= ~ipsrst2_bits;
254 	iprst3 &= ~ipsrst3_bits;
255 
256 	writel(iprst1, rc->base + NPCM_IPSRST1);
257 	writel(iprst2, rc->base + NPCM_IPSRST2);
258 	writel(iprst3, rc->base + NPCM_IPSRST3);
259 }
260 
261 static void npcm_usb_reset_npcm8xx(struct npcm_rc_data *rc)
262 {
263 	u32 mdlr, iprst1, iprst2, iprst3, iprst4;
264 	u32 ipsrst1_bits = 0;
265 	u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST;
266 	u32 ipsrst3_bits = 0;
267 	u32 ipsrst4_bits = NPCM_IPSRST4_USB_HOST2 | NPCM_IPSRST4_USBPHY3;
268 
269 	/* checking which USB device is enabled */
270 	regmap_read(rc->gcr_regmap, NPCM_MDLR_OFFSET, &mdlr);
271 	if (!(mdlr & NPCM8XX_MDLR_USBD0_3)) {
272 		ipsrst3_bits |= NPCM_IPSRST3_USBD0;
273 		ipsrst1_bits |= (NPCM_IPSRST1_USBD1 |
274 				 NPCM_IPSRST1_USBD2 |
275 				 NPCM_IPSRST1_USBD3);
276 	}
277 	if (!(mdlr & NPCM8XX_MDLR_USBD4_7)) {
278 		ipsrst1_bits |= (NPCM_IPSRST1_USBD4 |
279 				 NPCM_IPSRST1_USBD5 |
280 				 NPCM_IPSRST1_USBD6);
281 		ipsrst3_bits |= NPCM_IPSRST3_USBD7;
282 	}
283 
284 	if (!(mdlr & NPCM8XX_MDLR_USBD8))
285 		ipsrst3_bits |= NPCM_IPSRST3_USBD8;
286 	if (!(mdlr & NPCM8XX_MDLR_USBD9))
287 		ipsrst3_bits |= NPCM_IPSRST3_USBD9;
288 
289 	/* assert reset USB PHY and USB devices */
290 	iprst1 = readl(rc->base + NPCM_IPSRST1);
291 	iprst2 = readl(rc->base + NPCM_IPSRST2);
292 	iprst3 = readl(rc->base + NPCM_IPSRST3);
293 	iprst4 = readl(rc->base + NPCM_IPSRST4);
294 
295 	iprst1 |= ipsrst1_bits;
296 	iprst2 |= ipsrst2_bits;
297 	iprst3 |= (ipsrst3_bits | NPCM_IPSRST3_USBPHY1 |
298 		   NPCM_IPSRST3_USBPHY2);
299 	iprst4 |= ipsrst4_bits;
300 
301 	writel(iprst1, rc->base + NPCM_IPSRST1);
302 	writel(iprst2, rc->base + NPCM_IPSRST2);
303 	writel(iprst3, rc->base + NPCM_IPSRST3);
304 	writel(iprst4, rc->base + NPCM_IPSRST4);
305 
306 	/* clear USB PHY RS bit */
307 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
308 			   NPCM_USBXPHYCTL_RS, 0);
309 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
310 			   NPCM_USBXPHYCTL_RS, 0);
311 	regmap_update_bits(rc->gcr_regmap, NPCM_USB3PHYCTL_OFFSET,
312 			   NPCM_USBXPHYCTL_RS, 0);
313 
314 	/* deassert reset USB PHY */
315 	iprst3 &= ~(NPCM_IPSRST3_USBPHY1 | NPCM_IPSRST3_USBPHY2);
316 	writel(iprst3, rc->base + NPCM_IPSRST3);
317 	iprst4 &= ~NPCM_IPSRST4_USBPHY3;
318 	writel(iprst4, rc->base + NPCM_IPSRST4);
319 
320 	/* set USB PHY RS bit */
321 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
322 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
323 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
324 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
325 	regmap_update_bits(rc->gcr_regmap, NPCM_USB3PHYCTL_OFFSET,
326 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
327 
328 	/* deassert reset USB devices*/
329 	iprst1 &= ~ipsrst1_bits;
330 	iprst2 &= ~ipsrst2_bits;
331 	iprst3 &= ~ipsrst3_bits;
332 	iprst4 &= ~ipsrst4_bits;
333 
334 	writel(iprst1, rc->base + NPCM_IPSRST1);
335 	writel(iprst2, rc->base + NPCM_IPSRST2);
336 	writel(iprst3, rc->base + NPCM_IPSRST3);
337 	writel(iprst4, rc->base + NPCM_IPSRST4);
338 }
339 
340 /*
341  *  The following procedure should be observed in USB PHY, USB device and
342  *  USB host initialization at BMC boot
343  */
344 static int npcm_usb_reset(struct platform_device *pdev, struct npcm_rc_data *rc)
345 {
346 	struct device *dev = &pdev->dev;
347 
348 	rc->gcr_regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "nuvoton,sysgcr");
349 	if (IS_ERR(rc->gcr_regmap)) {
350 		dev_warn(&pdev->dev, "Failed to find nuvoton,sysgcr property, please update the device tree\n");
351 		dev_info(&pdev->dev, "Using nuvoton,npcm750-gcr for Poleg backward compatibility\n");
352 		rc->gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
353 		if (IS_ERR(rc->gcr_regmap)) {
354 			dev_err(&pdev->dev, "Failed to find nuvoton,npcm750-gcr");
355 			return PTR_ERR(rc->gcr_regmap);
356 		}
357 	}
358 
359 	rc->info = device_get_match_data(dev);
360 	switch (rc->info->bmc_id) {
361 	case BMC_NPCM7XX:
362 		npcm_usb_reset_npcm7xx(rc);
363 		break;
364 	case BMC_NPCM8XX:
365 		npcm_usb_reset_npcm8xx(rc);
366 		break;
367 	default:
368 		return -ENODEV;
369 	}
370 
371 	return 0;
372 }
373 
374 static const struct reset_control_ops npcm_rc_ops = {
375 	.assert		= npcm_rc_assert,
376 	.deassert	= npcm_rc_deassert,
377 	.status		= npcm_rc_status,
378 };
379 
380 static void npcm_clock_unregister_adev(void *_adev)
381 {
382 	struct auxiliary_device *adev = _adev;
383 
384 	auxiliary_device_delete(adev);
385 	auxiliary_device_uninit(adev);
386 }
387 
388 static void npcm_clock_adev_release(struct device *dev)
389 {
390 	struct auxiliary_device *adev = to_auxiliary_dev(dev);
391 	struct npcm_clock_adev *rdev = to_npcm_clock_adev(adev);
392 
393 	kfree(rdev);
394 }
395 
396 static struct auxiliary_device *npcm_clock_adev_alloc(struct npcm_rc_data *rst_data, char *clk_name)
397 {
398 	struct npcm_clock_adev *rdev;
399 	struct auxiliary_device *adev;
400 	int ret;
401 
402 	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
403 	if (!rdev)
404 		return ERR_PTR(-ENOMEM);
405 
406 	rdev->base = rst_data->base;
407 
408 	adev = &rdev->adev;
409 	adev->name = clk_name;
410 	adev->dev.parent = rst_data->dev;
411 	adev->dev.release = npcm_clock_adev_release;
412 	adev->id = 555u;
413 
414 	ret = auxiliary_device_init(adev);
415 	if (ret) {
416 		kfree(rdev);
417 		return ERR_PTR(ret);
418 	}
419 
420 	return adev;
421 }
422 
423 static int npcm8xx_clock_controller_register(struct npcm_rc_data *rst_data, char *clk_name)
424 {
425 	struct auxiliary_device *adev;
426 	int ret;
427 
428 	adev = npcm_clock_adev_alloc(rst_data, clk_name);
429 	if (IS_ERR(adev))
430 		return PTR_ERR(adev);
431 
432 	ret = auxiliary_device_add(adev);
433 	if (ret) {
434 		auxiliary_device_uninit(adev);
435 		return ret;
436 	}
437 
438 	return devm_add_action_or_reset(rst_data->dev, npcm_clock_unregister_adev, adev);
439 }
440 
441 static int npcm_rc_probe(struct platform_device *pdev)
442 {
443 	struct npcm_rc_data *rc;
444 	int ret;
445 
446 	rc = devm_kzalloc(&pdev->dev, sizeof(*rc), GFP_KERNEL);
447 	if (!rc)
448 		return -ENOMEM;
449 
450 	rc->base = devm_platform_ioremap_resource(pdev, 0);
451 	if (IS_ERR(rc->base))
452 		return PTR_ERR(rc->base);
453 
454 	spin_lock_init(&rc->lock);
455 
456 	rc->rcdev.owner = THIS_MODULE;
457 	rc->rcdev.ops = &npcm_rc_ops;
458 	rc->rcdev.of_node = pdev->dev.of_node;
459 	rc->rcdev.of_reset_n_cells = 2;
460 	rc->rcdev.of_xlate = npcm_reset_xlate;
461 	rc->dev = &pdev->dev;
462 
463 	ret = devm_reset_controller_register(&pdev->dev, &rc->rcdev);
464 	if (ret) {
465 		dev_err(&pdev->dev, "unable to register device\n");
466 		return ret;
467 	}
468 
469 	if (npcm_usb_reset(pdev, rc))
470 		dev_warn(&pdev->dev, "NPCM USB reset failed, can cause issues with UDC and USB host\n");
471 
472 	if (!of_property_read_u32(pdev->dev.of_node, "nuvoton,sw-reset-number",
473 				  &rc->sw_reset_number)) {
474 		if (rc->sw_reset_number && rc->sw_reset_number < 5) {
475 			rc->restart_nb.priority = 192;
476 			rc->restart_nb.notifier_call = npcm_rc_restart;
477 			ret = register_restart_handler(&rc->restart_nb);
478 			if (ret) {
479 				dev_warn(&pdev->dev, "failed to register restart handler\n");
480 				return ret;
481 			}
482 		}
483 	}
484 
485 	switch (rc->info->bmc_id) {
486 	case BMC_NPCM8XX:
487 		return npcm8xx_clock_controller_register(rc, "clk-npcm8xx");
488 	default:
489 		return 0;
490 	}
491 }
492 
493 static struct platform_driver npcm_rc_driver = {
494 	.probe	= npcm_rc_probe,
495 	.driver	= {
496 		.name			= "npcm-reset",
497 		.of_match_table		= npcm_rc_match,
498 		.suppress_bind_attrs	= true,
499 	},
500 };
501 builtin_platform_driver(npcm_rc_driver);
502