xref: /linux/drivers/reset/reset-npcm.c (revision c76350e7add86344beae4cd69fffdf63284a4bf5)
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 	const struct npcm_reset_info *info;
93 	struct regmap *gcr_regmap;
94 	u32 sw_reset_number;
95 	struct device *dev;
96 	void __iomem *base;
97 	spinlock_t lock;
98 };
99 
100 #define to_rc_data(p) container_of(p, struct npcm_rc_data, rcdev)
101 
102 static int npcm_rc_restart(struct sys_off_data *data)
103 {
104 	struct npcm_rc_data *rc = data->cb_data;
105 
106 	writel(NPCM_SWRST << rc->sw_reset_number, rc->base + NPCM_SWRSTR);
107 	mdelay(1000);
108 
109 	pr_emerg("%s: unable to restart system\n", __func__);
110 
111 	return NOTIFY_DONE;
112 }
113 
114 static int npcm_rc_setclear_reset(struct reset_controller_dev *rcdev,
115 				  unsigned long id, bool set)
116 {
117 	struct npcm_rc_data *rc = to_rc_data(rcdev);
118 	unsigned int rst_bit = BIT(id & NPCM_MASK_RESETS);
119 	unsigned int ctrl_offset = id >> 8;
120 	unsigned long flags;
121 	u32 stat;
122 
123 	spin_lock_irqsave(&rc->lock, flags);
124 	stat = readl(rc->base + ctrl_offset);
125 	if (set)
126 		writel(stat | rst_bit, rc->base + ctrl_offset);
127 	else
128 		writel(stat & ~rst_bit, rc->base + ctrl_offset);
129 	spin_unlock_irqrestore(&rc->lock, flags);
130 
131 	return 0;
132 }
133 
134 static int npcm_rc_assert(struct reset_controller_dev *rcdev, unsigned long id)
135 {
136 	return npcm_rc_setclear_reset(rcdev, id, true);
137 }
138 
139 static int npcm_rc_deassert(struct reset_controller_dev *rcdev,
140 			    unsigned long id)
141 {
142 	return npcm_rc_setclear_reset(rcdev, id, false);
143 }
144 
145 static int npcm_rc_status(struct reset_controller_dev *rcdev,
146 			  unsigned long id)
147 {
148 	struct npcm_rc_data *rc = to_rc_data(rcdev);
149 	unsigned int rst_bit = BIT(id & NPCM_MASK_RESETS);
150 	unsigned int ctrl_offset = id >> 8;
151 
152 	return (readl(rc->base + ctrl_offset) & rst_bit);
153 }
154 
155 static int npcm_reset_xlate(struct reset_controller_dev *rcdev,
156 			    const struct of_phandle_args *reset_spec)
157 {
158 	struct npcm_rc_data *rc = to_rc_data(rcdev);
159 	unsigned int offset, bit;
160 	bool offset_found = false;
161 	int off_num;
162 
163 	offset = reset_spec->args[0];
164 	for (off_num = 0 ; off_num < rc->info->num_ipsrst ; off_num++) {
165 		if (offset == rc->info->ipsrst[off_num]) {
166 			offset_found = true;
167 			break;
168 		}
169 	}
170 
171 	if (!offset_found) {
172 		dev_err(rcdev->dev, "Error reset register (0x%x)\n", offset);
173 		return -EINVAL;
174 	}
175 
176 	bit = reset_spec->args[1];
177 	if (bit >= NPCM_RC_RESETS_PER_REG) {
178 		dev_err(rcdev->dev, "Error reset number (%d)\n", bit);
179 		return -EINVAL;
180 	}
181 
182 	return (offset << 8) | bit;
183 }
184 
185 static const struct of_device_id npcm_rc_match[] = {
186 	{ .compatible = "nuvoton,npcm750-reset", .data = &npxm7xx_reset_info},
187 	{ .compatible = "nuvoton,npcm845-reset", .data = &npxm8xx_reset_info},
188 	{ }
189 };
190 
191 static void npcm_usb_reset_npcm7xx(struct npcm_rc_data *rc)
192 {
193 	u32 mdlr, iprst1, iprst2, iprst3;
194 	u32 ipsrst1_bits = 0;
195 	u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST;
196 	u32 ipsrst3_bits = 0;
197 
198 	/* checking which USB device is enabled */
199 	regmap_read(rc->gcr_regmap, NPCM_MDLR_OFFSET, &mdlr);
200 	if (!(mdlr & NPCM7XX_MDLR_USBD0))
201 		ipsrst3_bits |= NPCM_IPSRST3_USBD0;
202 	if (!(mdlr & NPCM7XX_MDLR_USBD1))
203 		ipsrst1_bits |= NPCM_IPSRST1_USBD1;
204 	if (!(mdlr & NPCM7XX_MDLR_USBD2_4))
205 		ipsrst1_bits |= (NPCM_IPSRST1_USBD2 |
206 				 NPCM_IPSRST1_USBD3 |
207 				 NPCM_IPSRST1_USBD4);
208 	if (!(mdlr & NPCM7XX_MDLR_USBD0)) {
209 		ipsrst1_bits |= (NPCM_IPSRST1_USBD5 |
210 				 NPCM_IPSRST1_USBD6);
211 		ipsrst3_bits |= (NPCM_IPSRST3_USBD7 |
212 				 NPCM_IPSRST3_USBD8 |
213 				 NPCM_IPSRST3_USBD9);
214 	}
215 
216 	/* assert reset USB PHY and USB devices */
217 	iprst1 = readl(rc->base + NPCM_IPSRST1);
218 	iprst2 = readl(rc->base + NPCM_IPSRST2);
219 	iprst3 = readl(rc->base + NPCM_IPSRST3);
220 
221 	iprst1 |= ipsrst1_bits;
222 	iprst2 |= ipsrst2_bits;
223 	iprst3 |= (ipsrst3_bits | NPCM_IPSRST3_USBPHY1 |
224 		   NPCM_IPSRST3_USBPHY2);
225 
226 	writel(iprst1, rc->base + NPCM_IPSRST1);
227 	writel(iprst2, rc->base + NPCM_IPSRST2);
228 	writel(iprst3, rc->base + NPCM_IPSRST3);
229 
230 	/* clear USB PHY RS bit */
231 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
232 			   NPCM_USBXPHYCTL_RS, 0);
233 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
234 			   NPCM_USBXPHYCTL_RS, 0);
235 
236 	/* deassert reset USB PHY */
237 	iprst3 &= ~(NPCM_IPSRST3_USBPHY1 | NPCM_IPSRST3_USBPHY2);
238 	writel(iprst3, rc->base + NPCM_IPSRST3);
239 
240 	udelay(50);
241 
242 	/* set USB PHY RS bit */
243 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
244 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
245 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
246 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
247 
248 	/* deassert reset USB devices*/
249 	iprst1 &= ~ipsrst1_bits;
250 	iprst2 &= ~ipsrst2_bits;
251 	iprst3 &= ~ipsrst3_bits;
252 
253 	writel(iprst1, rc->base + NPCM_IPSRST1);
254 	writel(iprst2, rc->base + NPCM_IPSRST2);
255 	writel(iprst3, rc->base + NPCM_IPSRST3);
256 }
257 
258 static void npcm_usb_reset_npcm8xx(struct npcm_rc_data *rc)
259 {
260 	u32 mdlr, iprst1, iprst2, iprst3, iprst4;
261 	u32 ipsrst1_bits = 0;
262 	u32 ipsrst2_bits = NPCM_IPSRST2_USB_HOST;
263 	u32 ipsrst3_bits = 0;
264 	u32 ipsrst4_bits = NPCM_IPSRST4_USB_HOST2 | NPCM_IPSRST4_USBPHY3;
265 
266 	/* checking which USB device is enabled */
267 	regmap_read(rc->gcr_regmap, NPCM_MDLR_OFFSET, &mdlr);
268 	if (!(mdlr & NPCM8XX_MDLR_USBD0_3)) {
269 		ipsrst3_bits |= NPCM_IPSRST3_USBD0;
270 		ipsrst1_bits |= (NPCM_IPSRST1_USBD1 |
271 				 NPCM_IPSRST1_USBD2 |
272 				 NPCM_IPSRST1_USBD3);
273 	}
274 	if (!(mdlr & NPCM8XX_MDLR_USBD4_7)) {
275 		ipsrst1_bits |= (NPCM_IPSRST1_USBD4 |
276 				 NPCM_IPSRST1_USBD5 |
277 				 NPCM_IPSRST1_USBD6);
278 		ipsrst3_bits |= NPCM_IPSRST3_USBD7;
279 	}
280 
281 	if (!(mdlr & NPCM8XX_MDLR_USBD8))
282 		ipsrst3_bits |= NPCM_IPSRST3_USBD8;
283 	if (!(mdlr & NPCM8XX_MDLR_USBD9))
284 		ipsrst3_bits |= NPCM_IPSRST3_USBD9;
285 
286 	/* assert reset USB PHY and USB devices */
287 	iprst1 = readl(rc->base + NPCM_IPSRST1);
288 	iprst2 = readl(rc->base + NPCM_IPSRST2);
289 	iprst3 = readl(rc->base + NPCM_IPSRST3);
290 	iprst4 = readl(rc->base + NPCM_IPSRST4);
291 
292 	iprst1 |= ipsrst1_bits;
293 	iprst2 |= ipsrst2_bits;
294 	iprst3 |= (ipsrst3_bits | NPCM_IPSRST3_USBPHY1 |
295 		   NPCM_IPSRST3_USBPHY2);
296 	iprst4 |= ipsrst4_bits;
297 
298 	writel(iprst1, rc->base + NPCM_IPSRST1);
299 	writel(iprst2, rc->base + NPCM_IPSRST2);
300 	writel(iprst3, rc->base + NPCM_IPSRST3);
301 	writel(iprst4, rc->base + NPCM_IPSRST4);
302 
303 	/* clear USB PHY RS bit */
304 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
305 			   NPCM_USBXPHYCTL_RS, 0);
306 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
307 			   NPCM_USBXPHYCTL_RS, 0);
308 	regmap_update_bits(rc->gcr_regmap, NPCM_USB3PHYCTL_OFFSET,
309 			   NPCM_USBXPHYCTL_RS, 0);
310 
311 	/* deassert reset USB PHY */
312 	iprst3 &= ~(NPCM_IPSRST3_USBPHY1 | NPCM_IPSRST3_USBPHY2);
313 	writel(iprst3, rc->base + NPCM_IPSRST3);
314 	iprst4 &= ~NPCM_IPSRST4_USBPHY3;
315 	writel(iprst4, rc->base + NPCM_IPSRST4);
316 
317 	/* set USB PHY RS bit */
318 	regmap_update_bits(rc->gcr_regmap, NPCM_USB1PHYCTL_OFFSET,
319 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
320 	regmap_update_bits(rc->gcr_regmap, NPCM_USB2PHYCTL_OFFSET,
321 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
322 	regmap_update_bits(rc->gcr_regmap, NPCM_USB3PHYCTL_OFFSET,
323 			   NPCM_USBXPHYCTL_RS, NPCM_USBXPHYCTL_RS);
324 
325 	/* deassert reset USB devices*/
326 	iprst1 &= ~ipsrst1_bits;
327 	iprst2 &= ~ipsrst2_bits;
328 	iprst3 &= ~ipsrst3_bits;
329 	iprst4 &= ~ipsrst4_bits;
330 
331 	writel(iprst1, rc->base + NPCM_IPSRST1);
332 	writel(iprst2, rc->base + NPCM_IPSRST2);
333 	writel(iprst3, rc->base + NPCM_IPSRST3);
334 	writel(iprst4, rc->base + NPCM_IPSRST4);
335 }
336 
337 /*
338  *  The following procedure should be observed in USB PHY, USB device and
339  *  USB host initialization at BMC boot
340  */
341 static int npcm_usb_reset(struct platform_device *pdev, struct npcm_rc_data *rc)
342 {
343 	struct device *dev = &pdev->dev;
344 
345 	rc->gcr_regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "nuvoton,sysgcr");
346 	if (IS_ERR(rc->gcr_regmap)) {
347 		dev_warn(&pdev->dev, "Failed to find nuvoton,sysgcr property, please update the device tree\n");
348 		dev_info(&pdev->dev, "Using nuvoton,npcm750-gcr for Poleg backward compatibility\n");
349 		rc->gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
350 		if (IS_ERR(rc->gcr_regmap)) {
351 			dev_err(&pdev->dev, "Failed to find nuvoton,npcm750-gcr");
352 			return PTR_ERR(rc->gcr_regmap);
353 		}
354 	}
355 
356 	rc->info = device_get_match_data(dev);
357 	switch (rc->info->bmc_id) {
358 	case BMC_NPCM7XX:
359 		npcm_usb_reset_npcm7xx(rc);
360 		break;
361 	case BMC_NPCM8XX:
362 		npcm_usb_reset_npcm8xx(rc);
363 		break;
364 	default:
365 		return -ENODEV;
366 	}
367 
368 	return 0;
369 }
370 
371 static const struct reset_control_ops npcm_rc_ops = {
372 	.assert		= npcm_rc_assert,
373 	.deassert	= npcm_rc_deassert,
374 	.status		= npcm_rc_status,
375 };
376 
377 static void npcm_clock_unregister_adev(void *_adev)
378 {
379 	struct auxiliary_device *adev = _adev;
380 
381 	auxiliary_device_delete(adev);
382 	auxiliary_device_uninit(adev);
383 }
384 
385 static void npcm_clock_adev_release(struct device *dev)
386 {
387 	struct auxiliary_device *adev = to_auxiliary_dev(dev);
388 	struct npcm_clock_adev *rdev = to_npcm_clock_adev(adev);
389 
390 	kfree(rdev);
391 }
392 
393 static struct auxiliary_device *npcm_clock_adev_alloc(struct npcm_rc_data *rst_data, char *clk_name)
394 {
395 	struct npcm_clock_adev *rdev;
396 	struct auxiliary_device *adev;
397 	int ret;
398 
399 	rdev = kzalloc_obj(*rdev);
400 	if (!rdev)
401 		return ERR_PTR(-ENOMEM);
402 
403 	rdev->base = rst_data->base;
404 
405 	adev = &rdev->adev;
406 	adev->name = clk_name;
407 	adev->dev.parent = rst_data->dev;
408 	adev->dev.release = npcm_clock_adev_release;
409 	adev->id = 555u;
410 
411 	ret = auxiliary_device_init(adev);
412 	if (ret) {
413 		kfree(rdev);
414 		return ERR_PTR(ret);
415 	}
416 
417 	return adev;
418 }
419 
420 static int npcm8xx_clock_controller_register(struct npcm_rc_data *rst_data, char *clk_name)
421 {
422 	struct auxiliary_device *adev;
423 	int ret;
424 
425 	adev = npcm_clock_adev_alloc(rst_data, clk_name);
426 	if (IS_ERR(adev))
427 		return PTR_ERR(adev);
428 
429 	ret = auxiliary_device_add(adev);
430 	if (ret) {
431 		auxiliary_device_uninit(adev);
432 		return ret;
433 	}
434 
435 	return devm_add_action_or_reset(rst_data->dev, npcm_clock_unregister_adev, adev);
436 }
437 
438 static int npcm_rc_probe(struct platform_device *pdev)
439 {
440 	struct npcm_rc_data *rc;
441 	int ret;
442 
443 	rc = devm_kzalloc(&pdev->dev, sizeof(*rc), GFP_KERNEL);
444 	if (!rc)
445 		return -ENOMEM;
446 
447 	rc->base = devm_platform_ioremap_resource(pdev, 0);
448 	if (IS_ERR(rc->base))
449 		return PTR_ERR(rc->base);
450 
451 	spin_lock_init(&rc->lock);
452 
453 	rc->rcdev.owner = THIS_MODULE;
454 	rc->rcdev.ops = &npcm_rc_ops;
455 	rc->rcdev.of_node = pdev->dev.of_node;
456 	rc->rcdev.of_reset_n_cells = 2;
457 	rc->rcdev.of_xlate = npcm_reset_xlate;
458 	rc->dev = &pdev->dev;
459 
460 	ret = devm_reset_controller_register(&pdev->dev, &rc->rcdev);
461 	if (ret) {
462 		dev_err(&pdev->dev, "unable to register device\n");
463 		return ret;
464 	}
465 
466 	if (npcm_usb_reset(pdev, rc))
467 		dev_warn(&pdev->dev, "NPCM USB reset failed, can cause issues with UDC and USB host\n");
468 
469 	if (!of_property_read_u32(pdev->dev.of_node, "nuvoton,sw-reset-number",
470 				  &rc->sw_reset_number)) {
471 		if (rc->sw_reset_number && rc->sw_reset_number < 5) {
472 			ret = devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_RESTART, 192,
473 							    npcm_rc_restart, rc);
474 			if (ret) {
475 				dev_warn(&pdev->dev, "failed to register restart handler\n");
476 				return ret;
477 			}
478 		}
479 	}
480 
481 	switch (rc->info->bmc_id) {
482 	case BMC_NPCM8XX:
483 		return npcm8xx_clock_controller_register(rc, "clk-npcm8xx");
484 	default:
485 		return 0;
486 	}
487 }
488 
489 static struct platform_driver npcm_rc_driver = {
490 	.probe	= npcm_rc_probe,
491 	.driver	= {
492 		.name			= "npcm-reset",
493 		.of_match_table		= npcm_rc_match,
494 		.suppress_bind_attrs	= true,
495 	},
496 };
497 builtin_platform_driver(npcm_rc_driver);
498