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  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
 70enum {
 71	BMC_NPCM7XX = 0,
 72	BMC_NPCM8XX,
 73};
 74
 75static const u32 npxm7xx_ipsrst[] = {NPCM_IPSRST1, NPCM_IPSRST2, NPCM_IPSRST3};
 76static const u32 npxm8xx_ipsrst[] = {NPCM_IPSRST1, NPCM_IPSRST2, NPCM_IPSRST3,
 77	NPCM_IPSRST4};
 78
 79struct npcm_reset_info {
 80	u32 bmc_id;
 81	u32 num_ipsrst;
 82	const u32 *ipsrst;
 83};
 84
 85static const struct npcm_reset_info npxm7xx_reset_info[] = {
 86	{.bmc_id = BMC_NPCM7XX, .num_ipsrst = 3, .ipsrst = npxm7xx_ipsrst}};
 87static const struct npcm_reset_info npxm8xx_reset_info[] = {
 88	{.bmc_id = BMC_NPCM8XX, .num_ipsrst = 4, .ipsrst = npxm8xx_ipsrst}};
 89
 90struct 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
103static 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
117static 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
137static int npcm_rc_assert(struct reset_controller_dev *rcdev, unsigned long id)
138{
139	return npcm_rc_setclear_reset(rcdev, id, true);
140}
141
142static 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
148static 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
158static 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
188static 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
194static 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
261static 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 */
344static 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
374static 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
380static 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
388static 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
396static 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
423static 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
441static 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
493static 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};
501builtin_platform_driver(npcm_rc_driver);