xref: /openbmc/linux/drivers/usb/musb/musb_dsps.c (revision e2f1cf25)
1 /*
2  * Texas Instruments DSPS platforms "glue layer"
3  *
4  * Copyright (C) 2012, by Texas Instruments
5  *
6  * Based on the am35x "glue layer" code.
7  *
8  * This file is part of the Inventra Controller Driver for Linux.
9  *
10  * The Inventra Controller Driver for Linux is free software; you
11  * can redistribute it and/or modify it under the terms of the GNU
12  * General Public License version 2 as published by the Free Software
13  * Foundation.
14  *
15  * The Inventra Controller Driver for Linux is distributed in
16  * the hope that it will be useful, but WITHOUT ANY WARRANTY;
17  * without even the implied warranty of MERCHANTABILITY or
18  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
19  * License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with The Inventra Controller Driver for Linux ; if not,
23  * write to the Free Software Foundation, Inc., 59 Temple Place,
24  * Suite 330, Boston, MA  02111-1307  USA
25  *
26  * musb_dsps.c will be a common file for all the TI DSPS platforms
27  * such as dm64x, dm36x, dm35x, da8x, am35x and ti81x.
28  * For now only ti81x is using this and in future davinci.c, am35x.c
29  * da8xx.c would be merged to this file after testing.
30  */
31 
32 #include <linux/io.h>
33 #include <linux/err.h>
34 #include <linux/platform_device.h>
35 #include <linux/dma-mapping.h>
36 #include <linux/pm_runtime.h>
37 #include <linux/module.h>
38 #include <linux/usb/usb_phy_generic.h>
39 #include <linux/platform_data/usb-omap.h>
40 #include <linux/sizes.h>
41 
42 #include <linux/of.h>
43 #include <linux/of_device.h>
44 #include <linux/of_address.h>
45 #include <linux/of_irq.h>
46 #include <linux/usb/of.h>
47 
48 #include <linux/debugfs.h>
49 
50 #include "musb_core.h"
51 
52 static const struct of_device_id musb_dsps_of_match[];
53 
54 /**
55  * avoid using musb_readx()/musb_writex() as glue layer should not be
56  * dependent on musb core layer symbols.
57  */
58 static inline u8 dsps_readb(const void __iomem *addr, unsigned offset)
59 {
60 	return __raw_readb(addr + offset);
61 }
62 
63 static inline u32 dsps_readl(const void __iomem *addr, unsigned offset)
64 {
65 	return __raw_readl(addr + offset);
66 }
67 
68 static inline void dsps_writeb(void __iomem *addr, unsigned offset, u8 data)
69 {
70 	__raw_writeb(data, addr + offset);
71 }
72 
73 static inline void dsps_writel(void __iomem *addr, unsigned offset, u32 data)
74 {
75 	__raw_writel(data, addr + offset);
76 }
77 
78 /**
79  * DSPS musb wrapper register offset.
80  * FIXME: This should be expanded to have all the wrapper registers from TI DSPS
81  * musb ips.
82  */
83 struct dsps_musb_wrapper {
84 	u16	revision;
85 	u16	control;
86 	u16	status;
87 	u16	epintr_set;
88 	u16	epintr_clear;
89 	u16	epintr_status;
90 	u16	coreintr_set;
91 	u16	coreintr_clear;
92 	u16	coreintr_status;
93 	u16	phy_utmi;
94 	u16	mode;
95 	u16	tx_mode;
96 	u16	rx_mode;
97 
98 	/* bit positions for control */
99 	unsigned	reset:5;
100 
101 	/* bit positions for interrupt */
102 	unsigned	usb_shift:5;
103 	u32		usb_mask;
104 	u32		usb_bitmap;
105 	unsigned	drvvbus:5;
106 
107 	unsigned	txep_shift:5;
108 	u32		txep_mask;
109 	u32		txep_bitmap;
110 
111 	unsigned	rxep_shift:5;
112 	u32		rxep_mask;
113 	u32		rxep_bitmap;
114 
115 	/* bit positions for phy_utmi */
116 	unsigned	otg_disable:5;
117 
118 	/* bit positions for mode */
119 	unsigned	iddig:5;
120 	unsigned	iddig_mux:5;
121 	/* miscellaneous stuff */
122 	unsigned	poll_timeout;
123 };
124 
125 /*
126  * register shadow for suspend
127  */
128 struct dsps_context {
129 	u32 control;
130 	u32 epintr;
131 	u32 coreintr;
132 	u32 phy_utmi;
133 	u32 mode;
134 	u32 tx_mode;
135 	u32 rx_mode;
136 };
137 
138 /**
139  * DSPS glue structure.
140  */
141 struct dsps_glue {
142 	struct device *dev;
143 	struct platform_device *musb;	/* child musb pdev */
144 	const struct dsps_musb_wrapper *wrp; /* wrapper register offsets */
145 	struct timer_list timer;	/* otg_workaround timer */
146 	unsigned long last_timer;    /* last timer data for each instance */
147 	bool sw_babble_enabled;
148 
149 	struct dsps_context context;
150 	struct debugfs_regset32 regset;
151 	struct dentry *dbgfs_root;
152 };
153 
154 static const struct debugfs_reg32 dsps_musb_regs[] = {
155 	{ "revision",		0x00 },
156 	{ "control",		0x14 },
157 	{ "status",		0x18 },
158 	{ "eoi",		0x24 },
159 	{ "intr0_stat",		0x30 },
160 	{ "intr1_stat",		0x34 },
161 	{ "intr0_set",		0x38 },
162 	{ "intr1_set",		0x3c },
163 	{ "txmode",		0x70 },
164 	{ "rxmode",		0x74 },
165 	{ "autoreq",		0xd0 },
166 	{ "srpfixtime",		0xd4 },
167 	{ "tdown",		0xd8 },
168 	{ "phy_utmi",		0xe0 },
169 	{ "mode",		0xe8 },
170 };
171 
172 static void dsps_musb_try_idle(struct musb *musb, unsigned long timeout)
173 {
174 	struct device *dev = musb->controller;
175 	struct dsps_glue *glue = dev_get_drvdata(dev->parent);
176 
177 	if (timeout == 0)
178 		timeout = jiffies + msecs_to_jiffies(3);
179 
180 	/* Never idle if active, or when VBUS timeout is not set as host */
181 	if (musb->is_active || (musb->a_wait_bcon == 0 &&
182 			musb->xceiv->otg->state == OTG_STATE_A_WAIT_BCON)) {
183 		dev_dbg(musb->controller, "%s active, deleting timer\n",
184 				usb_otg_state_string(musb->xceiv->otg->state));
185 		del_timer(&glue->timer);
186 		glue->last_timer = jiffies;
187 		return;
188 	}
189 	if (musb->port_mode != MUSB_PORT_MODE_DUAL_ROLE)
190 		return;
191 
192 	if (!musb->g.dev.driver)
193 		return;
194 
195 	if (time_after(glue->last_timer, timeout) &&
196 				timer_pending(&glue->timer)) {
197 		dev_dbg(musb->controller,
198 			"Longer idle timer already pending, ignoring...\n");
199 		return;
200 	}
201 	glue->last_timer = timeout;
202 
203 	dev_dbg(musb->controller, "%s inactive, starting idle timer for %u ms\n",
204 		usb_otg_state_string(musb->xceiv->otg->state),
205 			jiffies_to_msecs(timeout - jiffies));
206 	mod_timer(&glue->timer, timeout);
207 }
208 
209 /**
210  * dsps_musb_enable - enable interrupts
211  */
212 static void dsps_musb_enable(struct musb *musb)
213 {
214 	struct device *dev = musb->controller;
215 	struct platform_device *pdev = to_platform_device(dev->parent);
216 	struct dsps_glue *glue = platform_get_drvdata(pdev);
217 	const struct dsps_musb_wrapper *wrp = glue->wrp;
218 	void __iomem *reg_base = musb->ctrl_base;
219 	u32 epmask, coremask;
220 
221 	/* Workaround: setup IRQs through both register sets. */
222 	epmask = ((musb->epmask & wrp->txep_mask) << wrp->txep_shift) |
223 	       ((musb->epmask & wrp->rxep_mask) << wrp->rxep_shift);
224 	coremask = (wrp->usb_bitmap & ~MUSB_INTR_SOF);
225 
226 	dsps_writel(reg_base, wrp->epintr_set, epmask);
227 	dsps_writel(reg_base, wrp->coreintr_set, coremask);
228 	/* start polling for ID change. */
229 	mod_timer(&glue->timer, jiffies + msecs_to_jiffies(wrp->poll_timeout));
230 	dsps_musb_try_idle(musb, 0);
231 }
232 
233 /**
234  * dsps_musb_disable - disable HDRC and flush interrupts
235  */
236 static void dsps_musb_disable(struct musb *musb)
237 {
238 	struct device *dev = musb->controller;
239 	struct platform_device *pdev = to_platform_device(dev->parent);
240 	struct dsps_glue *glue = platform_get_drvdata(pdev);
241 	const struct dsps_musb_wrapper *wrp = glue->wrp;
242 	void __iomem *reg_base = musb->ctrl_base;
243 
244 	dsps_writel(reg_base, wrp->coreintr_clear, wrp->usb_bitmap);
245 	dsps_writel(reg_base, wrp->epintr_clear,
246 			 wrp->txep_bitmap | wrp->rxep_bitmap);
247 	dsps_writeb(musb->mregs, MUSB_DEVCTL, 0);
248 }
249 
250 static void otg_timer(unsigned long _musb)
251 {
252 	struct musb *musb = (void *)_musb;
253 	void __iomem *mregs = musb->mregs;
254 	struct device *dev = musb->controller;
255 	struct dsps_glue *glue = dev_get_drvdata(dev->parent);
256 	const struct dsps_musb_wrapper *wrp = glue->wrp;
257 	u8 devctl;
258 	unsigned long flags;
259 	int skip_session = 0;
260 
261 	/*
262 	 * We poll because DSPS IP's won't expose several OTG-critical
263 	 * status change events (from the transceiver) otherwise.
264 	 */
265 	devctl = dsps_readb(mregs, MUSB_DEVCTL);
266 	dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl,
267 				usb_otg_state_string(musb->xceiv->otg->state));
268 
269 	spin_lock_irqsave(&musb->lock, flags);
270 	switch (musb->xceiv->otg->state) {
271 	case OTG_STATE_A_WAIT_BCON:
272 		dsps_writeb(musb->mregs, MUSB_DEVCTL, 0);
273 		skip_session = 1;
274 		/* fall */
275 
276 	case OTG_STATE_A_IDLE:
277 	case OTG_STATE_B_IDLE:
278 		if (devctl & MUSB_DEVCTL_BDEVICE) {
279 			musb->xceiv->otg->state = OTG_STATE_B_IDLE;
280 			MUSB_DEV_MODE(musb);
281 		} else {
282 			musb->xceiv->otg->state = OTG_STATE_A_IDLE;
283 			MUSB_HST_MODE(musb);
284 		}
285 		if (!(devctl & MUSB_DEVCTL_SESSION) && !skip_session)
286 			dsps_writeb(mregs, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
287 		mod_timer(&glue->timer, jiffies +
288 				msecs_to_jiffies(wrp->poll_timeout));
289 		break;
290 	case OTG_STATE_A_WAIT_VFALL:
291 		musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
292 		dsps_writel(musb->ctrl_base, wrp->coreintr_set,
293 			    MUSB_INTR_VBUSERROR << wrp->usb_shift);
294 		break;
295 	default:
296 		break;
297 	}
298 	spin_unlock_irqrestore(&musb->lock, flags);
299 }
300 
301 static irqreturn_t dsps_interrupt(int irq, void *hci)
302 {
303 	struct musb  *musb = hci;
304 	void __iomem *reg_base = musb->ctrl_base;
305 	struct device *dev = musb->controller;
306 	struct dsps_glue *glue = dev_get_drvdata(dev->parent);
307 	const struct dsps_musb_wrapper *wrp = glue->wrp;
308 	unsigned long flags;
309 	irqreturn_t ret = IRQ_NONE;
310 	u32 epintr, usbintr;
311 
312 	spin_lock_irqsave(&musb->lock, flags);
313 
314 	/* Get endpoint interrupts */
315 	epintr = dsps_readl(reg_base, wrp->epintr_status);
316 	musb->int_rx = (epintr & wrp->rxep_bitmap) >> wrp->rxep_shift;
317 	musb->int_tx = (epintr & wrp->txep_bitmap) >> wrp->txep_shift;
318 
319 	if (epintr)
320 		dsps_writel(reg_base, wrp->epintr_status, epintr);
321 
322 	/* Get usb core interrupts */
323 	usbintr = dsps_readl(reg_base, wrp->coreintr_status);
324 	if (!usbintr && !epintr)
325 		goto out;
326 
327 	musb->int_usb =	(usbintr & wrp->usb_bitmap) >> wrp->usb_shift;
328 	if (usbintr)
329 		dsps_writel(reg_base, wrp->coreintr_status, usbintr);
330 
331 	dev_dbg(musb->controller, "usbintr (%x) epintr(%x)\n",
332 			usbintr, epintr);
333 
334 	if (usbintr & ((1 << wrp->drvvbus) << wrp->usb_shift)) {
335 		int drvvbus = dsps_readl(reg_base, wrp->status);
336 		void __iomem *mregs = musb->mregs;
337 		u8 devctl = dsps_readb(mregs, MUSB_DEVCTL);
338 		int err;
339 
340 		err = musb->int_usb & MUSB_INTR_VBUSERROR;
341 		if (err) {
342 			/*
343 			 * The Mentor core doesn't debounce VBUS as needed
344 			 * to cope with device connect current spikes. This
345 			 * means it's not uncommon for bus-powered devices
346 			 * to get VBUS errors during enumeration.
347 			 *
348 			 * This is a workaround, but newer RTL from Mentor
349 			 * seems to allow a better one: "re"-starting sessions
350 			 * without waiting for VBUS to stop registering in
351 			 * devctl.
352 			 */
353 			musb->int_usb &= ~MUSB_INTR_VBUSERROR;
354 			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VFALL;
355 			mod_timer(&glue->timer, jiffies +
356 					msecs_to_jiffies(wrp->poll_timeout));
357 			WARNING("VBUS error workaround (delay coming)\n");
358 		} else if (drvvbus) {
359 			MUSB_HST_MODE(musb);
360 			musb->xceiv->otg->default_a = 1;
361 			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
362 			del_timer(&glue->timer);
363 		} else {
364 			musb->is_active = 0;
365 			MUSB_DEV_MODE(musb);
366 			musb->xceiv->otg->default_a = 0;
367 			musb->xceiv->otg->state = OTG_STATE_B_IDLE;
368 		}
369 
370 		/* NOTE: this must complete power-on within 100 ms. */
371 		dev_dbg(musb->controller, "VBUS %s (%s)%s, devctl %02x\n",
372 				drvvbus ? "on" : "off",
373 				usb_otg_state_string(musb->xceiv->otg->state),
374 				err ? " ERROR" : "",
375 				devctl);
376 		ret = IRQ_HANDLED;
377 	}
378 
379 	if (musb->int_tx || musb->int_rx || musb->int_usb)
380 		ret |= musb_interrupt(musb);
381 
382 	/* Poll for ID change in OTG port mode */
383 	if (musb->xceiv->otg->state == OTG_STATE_B_IDLE &&
384 			musb->port_mode == MUSB_PORT_MODE_DUAL_ROLE)
385 		mod_timer(&glue->timer, jiffies +
386 				msecs_to_jiffies(wrp->poll_timeout));
387 out:
388 	spin_unlock_irqrestore(&musb->lock, flags);
389 
390 	return ret;
391 }
392 
393 static int dsps_musb_dbg_init(struct musb *musb, struct dsps_glue *glue)
394 {
395 	struct dentry *root;
396 	struct dentry *file;
397 	char buf[128];
398 
399 	sprintf(buf, "%s.dsps", dev_name(musb->controller));
400 	root = debugfs_create_dir(buf, NULL);
401 	if (!root)
402 		return -ENOMEM;
403 	glue->dbgfs_root = root;
404 
405 	glue->regset.regs = dsps_musb_regs;
406 	glue->regset.nregs = ARRAY_SIZE(dsps_musb_regs);
407 	glue->regset.base = musb->ctrl_base;
408 
409 	file = debugfs_create_regset32("regdump", S_IRUGO, root, &glue->regset);
410 	if (!file) {
411 		debugfs_remove_recursive(root);
412 		return -ENOMEM;
413 	}
414 	return 0;
415 }
416 
417 static int dsps_musb_init(struct musb *musb)
418 {
419 	struct device *dev = musb->controller;
420 	struct dsps_glue *glue = dev_get_drvdata(dev->parent);
421 	struct platform_device *parent = to_platform_device(dev->parent);
422 	const struct dsps_musb_wrapper *wrp = glue->wrp;
423 	void __iomem *reg_base;
424 	struct resource *r;
425 	u32 rev, val;
426 	int ret;
427 
428 	r = platform_get_resource_byname(parent, IORESOURCE_MEM, "control");
429 	reg_base = devm_ioremap_resource(dev, r);
430 	if (IS_ERR(reg_base))
431 		return PTR_ERR(reg_base);
432 	musb->ctrl_base = reg_base;
433 
434 	/* NOP driver needs change if supporting dual instance */
435 	musb->xceiv = devm_usb_get_phy_by_phandle(dev->parent, "phys", 0);
436 	if (IS_ERR(musb->xceiv))
437 		return PTR_ERR(musb->xceiv);
438 
439 	musb->phy = devm_phy_get(dev->parent, "usb2-phy");
440 
441 	/* Returns zero if e.g. not clocked */
442 	rev = dsps_readl(reg_base, wrp->revision);
443 	if (!rev)
444 		return -ENODEV;
445 
446 	usb_phy_init(musb->xceiv);
447 	if (IS_ERR(musb->phy))  {
448 		musb->phy = NULL;
449 	} else {
450 		ret = phy_init(musb->phy);
451 		if (ret < 0)
452 			return ret;
453 		ret = phy_power_on(musb->phy);
454 		if (ret) {
455 			phy_exit(musb->phy);
456 			return ret;
457 		}
458 	}
459 
460 	setup_timer(&glue->timer, otg_timer, (unsigned long) musb);
461 
462 	/* Reset the musb */
463 	dsps_writel(reg_base, wrp->control, (1 << wrp->reset));
464 
465 	musb->isr = dsps_interrupt;
466 
467 	/* reset the otgdisable bit, needed for host mode to work */
468 	val = dsps_readl(reg_base, wrp->phy_utmi);
469 	val &= ~(1 << wrp->otg_disable);
470 	dsps_writel(musb->ctrl_base, wrp->phy_utmi, val);
471 
472 	/*
473 	 *  Check whether the dsps version has babble control enabled.
474 	 * In latest silicon revision the babble control logic is enabled.
475 	 * If MUSB_BABBLE_CTL returns 0x4 then we have the babble control
476 	 * logic enabled.
477 	 */
478 	val = dsps_readb(musb->mregs, MUSB_BABBLE_CTL);
479 	if (val & MUSB_BABBLE_RCV_DISABLE) {
480 		glue->sw_babble_enabled = true;
481 		val |= MUSB_BABBLE_SW_SESSION_CTRL;
482 		dsps_writeb(musb->mregs, MUSB_BABBLE_CTL, val);
483 	}
484 
485 	ret = dsps_musb_dbg_init(musb, glue);
486 	if (ret)
487 		return ret;
488 
489 	return 0;
490 }
491 
492 static int dsps_musb_exit(struct musb *musb)
493 {
494 	struct device *dev = musb->controller;
495 	struct dsps_glue *glue = dev_get_drvdata(dev->parent);
496 
497 	del_timer_sync(&glue->timer);
498 	usb_phy_shutdown(musb->xceiv);
499 	phy_power_off(musb->phy);
500 	phy_exit(musb->phy);
501 	debugfs_remove_recursive(glue->dbgfs_root);
502 
503 	return 0;
504 }
505 
506 static int dsps_musb_set_mode(struct musb *musb, u8 mode)
507 {
508 	struct device *dev = musb->controller;
509 	struct dsps_glue *glue = dev_get_drvdata(dev->parent);
510 	const struct dsps_musb_wrapper *wrp = glue->wrp;
511 	void __iomem *ctrl_base = musb->ctrl_base;
512 	u32 reg;
513 
514 	reg = dsps_readl(ctrl_base, wrp->mode);
515 
516 	switch (mode) {
517 	case MUSB_HOST:
518 		reg &= ~(1 << wrp->iddig);
519 
520 		/*
521 		 * if we're setting mode to host-only or device-only, we're
522 		 * going to ignore whatever the PHY sends us and just force
523 		 * ID pin status by SW
524 		 */
525 		reg |= (1 << wrp->iddig_mux);
526 
527 		dsps_writel(ctrl_base, wrp->mode, reg);
528 		dsps_writel(ctrl_base, wrp->phy_utmi, 0x02);
529 		break;
530 	case MUSB_PERIPHERAL:
531 		reg |= (1 << wrp->iddig);
532 
533 		/*
534 		 * if we're setting mode to host-only or device-only, we're
535 		 * going to ignore whatever the PHY sends us and just force
536 		 * ID pin status by SW
537 		 */
538 		reg |= (1 << wrp->iddig_mux);
539 
540 		dsps_writel(ctrl_base, wrp->mode, reg);
541 		break;
542 	case MUSB_OTG:
543 		dsps_writel(ctrl_base, wrp->phy_utmi, 0x02);
544 		break;
545 	default:
546 		dev_err(glue->dev, "unsupported mode %d\n", mode);
547 		return -EINVAL;
548 	}
549 
550 	return 0;
551 }
552 
553 static bool dsps_sw_babble_control(struct musb *musb)
554 {
555 	u8 babble_ctl;
556 	bool session_restart =  false;
557 
558 	babble_ctl = dsps_readb(musb->mregs, MUSB_BABBLE_CTL);
559 	dev_dbg(musb->controller, "babble: MUSB_BABBLE_CTL value %x\n",
560 		babble_ctl);
561 	/*
562 	 * check line monitor flag to check whether babble is
563 	 * due to noise
564 	 */
565 	dev_dbg(musb->controller, "STUCK_J is %s\n",
566 		babble_ctl & MUSB_BABBLE_STUCK_J ? "set" : "reset");
567 
568 	if (babble_ctl & MUSB_BABBLE_STUCK_J) {
569 		int timeout = 10;
570 
571 		/*
572 		 * babble is due to noise, then set transmit idle (d7 bit)
573 		 * to resume normal operation
574 		 */
575 		babble_ctl = dsps_readb(musb->mregs, MUSB_BABBLE_CTL);
576 		babble_ctl |= MUSB_BABBLE_FORCE_TXIDLE;
577 		dsps_writeb(musb->mregs, MUSB_BABBLE_CTL, babble_ctl);
578 
579 		/* wait till line monitor flag cleared */
580 		dev_dbg(musb->controller, "Set TXIDLE, wait J to clear\n");
581 		do {
582 			babble_ctl = dsps_readb(musb->mregs, MUSB_BABBLE_CTL);
583 			udelay(1);
584 		} while ((babble_ctl & MUSB_BABBLE_STUCK_J) && timeout--);
585 
586 		/* check whether stuck_at_j bit cleared */
587 		if (babble_ctl & MUSB_BABBLE_STUCK_J) {
588 			/*
589 			 * real babble condition has occurred
590 			 * restart the controller to start the
591 			 * session again
592 			 */
593 			dev_dbg(musb->controller, "J not cleared, misc (%x)\n",
594 				babble_ctl);
595 			session_restart = true;
596 		}
597 	} else {
598 		session_restart = true;
599 	}
600 
601 	return session_restart;
602 }
603 
604 static int dsps_musb_recover(struct musb *musb)
605 {
606 	struct device *dev = musb->controller;
607 	struct dsps_glue *glue = dev_get_drvdata(dev->parent);
608 	int session_restart = 0;
609 
610 	if (glue->sw_babble_enabled)
611 		session_restart = dsps_sw_babble_control(musb);
612 	else
613 		session_restart = 1;
614 
615 	return session_restart ? 0 : -EPIPE;
616 }
617 
618 /* Similar to am35x, dm81xx support only 32-bit read operation */
619 static void dsps_read_fifo32(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
620 {
621 	void __iomem *fifo = hw_ep->fifo;
622 
623 	if (len >= 4) {
624 		ioread32_rep(fifo, dst, len >> 2);
625 		dst += len & ~0x03;
626 		len &= 0x03;
627 	}
628 
629 	/* Read any remaining 1 to 3 bytes */
630 	if (len > 0) {
631 		u32 val = musb_readl(fifo, 0);
632 		memcpy(dst, &val, len);
633 	}
634 }
635 
636 static struct musb_platform_ops dsps_ops = {
637 	.quirks		= MUSB_DMA_CPPI41 | MUSB_INDEXED_EP,
638 	.init		= dsps_musb_init,
639 	.exit		= dsps_musb_exit,
640 
641 #ifdef CONFIG_USB_TI_CPPI41_DMA
642 	.dma_init	= cppi41_dma_controller_create,
643 	.dma_exit	= cppi41_dma_controller_destroy,
644 #endif
645 	.enable		= dsps_musb_enable,
646 	.disable	= dsps_musb_disable,
647 
648 	.try_idle	= dsps_musb_try_idle,
649 	.set_mode	= dsps_musb_set_mode,
650 	.recover	= dsps_musb_recover,
651 };
652 
653 static u64 musb_dmamask = DMA_BIT_MASK(32);
654 
655 static int get_int_prop(struct device_node *dn, const char *s)
656 {
657 	int ret;
658 	u32 val;
659 
660 	ret = of_property_read_u32(dn, s, &val);
661 	if (ret)
662 		return 0;
663 	return val;
664 }
665 
666 static int get_musb_port_mode(struct device *dev)
667 {
668 	enum usb_dr_mode mode;
669 
670 	mode = of_usb_get_dr_mode(dev->of_node);
671 	switch (mode) {
672 	case USB_DR_MODE_HOST:
673 		return MUSB_PORT_MODE_HOST;
674 
675 	case USB_DR_MODE_PERIPHERAL:
676 		return MUSB_PORT_MODE_GADGET;
677 
678 	case USB_DR_MODE_UNKNOWN:
679 	case USB_DR_MODE_OTG:
680 	default:
681 		return MUSB_PORT_MODE_DUAL_ROLE;
682 	}
683 }
684 
685 static int dsps_create_musb_pdev(struct dsps_glue *glue,
686 		struct platform_device *parent)
687 {
688 	struct musb_hdrc_platform_data pdata;
689 	struct resource	resources[2];
690 	struct resource	*res;
691 	struct device *dev = &parent->dev;
692 	struct musb_hdrc_config	*config;
693 	struct platform_device *musb;
694 	struct device_node *dn = parent->dev.of_node;
695 	int ret, val;
696 
697 	memset(resources, 0, sizeof(resources));
698 	res = platform_get_resource_byname(parent, IORESOURCE_MEM, "mc");
699 	if (!res) {
700 		dev_err(dev, "failed to get memory.\n");
701 		return -EINVAL;
702 	}
703 	resources[0] = *res;
704 
705 	res = platform_get_resource_byname(parent, IORESOURCE_IRQ, "mc");
706 	if (!res) {
707 		dev_err(dev, "failed to get irq.\n");
708 		return -EINVAL;
709 	}
710 	resources[1] = *res;
711 
712 	/* allocate the child platform device */
713 	musb = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
714 	if (!musb) {
715 		dev_err(dev, "failed to allocate musb device\n");
716 		return -ENOMEM;
717 	}
718 
719 	musb->dev.parent		= dev;
720 	musb->dev.dma_mask		= &musb_dmamask;
721 	musb->dev.coherent_dma_mask	= musb_dmamask;
722 
723 	glue->musb = musb;
724 
725 	ret = platform_device_add_resources(musb, resources,
726 			ARRAY_SIZE(resources));
727 	if (ret) {
728 		dev_err(dev, "failed to add resources\n");
729 		goto err;
730 	}
731 
732 	config = devm_kzalloc(&parent->dev, sizeof(*config), GFP_KERNEL);
733 	if (!config) {
734 		ret = -ENOMEM;
735 		goto err;
736 	}
737 	pdata.config = config;
738 	pdata.platform_ops = &dsps_ops;
739 
740 	config->num_eps = get_int_prop(dn, "mentor,num-eps");
741 	config->ram_bits = get_int_prop(dn, "mentor,ram-bits");
742 	config->host_port_deassert_reset_at_resume = 1;
743 	pdata.mode = get_musb_port_mode(dev);
744 	/* DT keeps this entry in mA, musb expects it as per USB spec */
745 	pdata.power = get_int_prop(dn, "mentor,power") / 2;
746 
747 	ret = of_property_read_u32(dn, "mentor,multipoint", &val);
748 	if (!ret && val)
749 		config->multipoint = true;
750 
751 	ret = platform_device_add_data(musb, &pdata, sizeof(pdata));
752 	if (ret) {
753 		dev_err(dev, "failed to add platform_data\n");
754 		goto err;
755 	}
756 
757 	ret = platform_device_add(musb);
758 	if (ret) {
759 		dev_err(dev, "failed to register musb device\n");
760 		goto err;
761 	}
762 	return 0;
763 
764 err:
765 	platform_device_put(musb);
766 	return ret;
767 }
768 
769 static int dsps_probe(struct platform_device *pdev)
770 {
771 	const struct of_device_id *match;
772 	const struct dsps_musb_wrapper *wrp;
773 	struct dsps_glue *glue;
774 	int ret;
775 
776 	if (!strcmp(pdev->name, "musb-hdrc"))
777 		return -ENODEV;
778 
779 	match = of_match_node(musb_dsps_of_match, pdev->dev.of_node);
780 	if (!match) {
781 		dev_err(&pdev->dev, "fail to get matching of_match struct\n");
782 		return -EINVAL;
783 	}
784 	wrp = match->data;
785 
786 	if (of_device_is_compatible(pdev->dev.of_node, "ti,musb-dm816"))
787 		dsps_ops.read_fifo = dsps_read_fifo32;
788 
789 	/* allocate glue */
790 	glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
791 	if (!glue)
792 		return -ENOMEM;
793 
794 	glue->dev = &pdev->dev;
795 	glue->wrp = wrp;
796 
797 	platform_set_drvdata(pdev, glue);
798 	pm_runtime_enable(&pdev->dev);
799 
800 	ret = pm_runtime_get_sync(&pdev->dev);
801 	if (ret < 0) {
802 		dev_err(&pdev->dev, "pm_runtime_get_sync FAILED");
803 		goto err2;
804 	}
805 
806 	ret = dsps_create_musb_pdev(glue, pdev);
807 	if (ret)
808 		goto err3;
809 
810 	return 0;
811 
812 err3:
813 	pm_runtime_put(&pdev->dev);
814 err2:
815 	pm_runtime_disable(&pdev->dev);
816 	return ret;
817 }
818 
819 static int dsps_remove(struct platform_device *pdev)
820 {
821 	struct dsps_glue *glue = platform_get_drvdata(pdev);
822 
823 	platform_device_unregister(glue->musb);
824 
825 	/* disable usbss clocks */
826 	pm_runtime_put(&pdev->dev);
827 	pm_runtime_disable(&pdev->dev);
828 
829 	return 0;
830 }
831 
832 static const struct dsps_musb_wrapper am33xx_driver_data = {
833 	.revision		= 0x00,
834 	.control		= 0x14,
835 	.status			= 0x18,
836 	.epintr_set		= 0x38,
837 	.epintr_clear		= 0x40,
838 	.epintr_status		= 0x30,
839 	.coreintr_set		= 0x3c,
840 	.coreintr_clear		= 0x44,
841 	.coreintr_status	= 0x34,
842 	.phy_utmi		= 0xe0,
843 	.mode			= 0xe8,
844 	.tx_mode		= 0x70,
845 	.rx_mode		= 0x74,
846 	.reset			= 0,
847 	.otg_disable		= 21,
848 	.iddig			= 8,
849 	.iddig_mux		= 7,
850 	.usb_shift		= 0,
851 	.usb_mask		= 0x1ff,
852 	.usb_bitmap		= (0x1ff << 0),
853 	.drvvbus		= 8,
854 	.txep_shift		= 0,
855 	.txep_mask		= 0xffff,
856 	.txep_bitmap		= (0xffff << 0),
857 	.rxep_shift		= 16,
858 	.rxep_mask		= 0xfffe,
859 	.rxep_bitmap		= (0xfffe << 16),
860 	.poll_timeout		= 2000, /* ms */
861 };
862 
863 static const struct of_device_id musb_dsps_of_match[] = {
864 	{ .compatible = "ti,musb-am33xx",
865 		.data = &am33xx_driver_data, },
866 	{ .compatible = "ti,musb-dm816",
867 		.data = &am33xx_driver_data, },
868 	{  },
869 };
870 MODULE_DEVICE_TABLE(of, musb_dsps_of_match);
871 
872 #ifdef CONFIG_PM_SLEEP
873 static int dsps_suspend(struct device *dev)
874 {
875 	struct dsps_glue *glue = dev_get_drvdata(dev);
876 	const struct dsps_musb_wrapper *wrp = glue->wrp;
877 	struct musb *musb = platform_get_drvdata(glue->musb);
878 	void __iomem *mbase;
879 
880 	del_timer_sync(&glue->timer);
881 
882 	if (!musb)
883 		/* This can happen if the musb device is in -EPROBE_DEFER */
884 		return 0;
885 
886 	mbase = musb->ctrl_base;
887 	glue->context.control = dsps_readl(mbase, wrp->control);
888 	glue->context.epintr = dsps_readl(mbase, wrp->epintr_set);
889 	glue->context.coreintr = dsps_readl(mbase, wrp->coreintr_set);
890 	glue->context.phy_utmi = dsps_readl(mbase, wrp->phy_utmi);
891 	glue->context.mode = dsps_readl(mbase, wrp->mode);
892 	glue->context.tx_mode = dsps_readl(mbase, wrp->tx_mode);
893 	glue->context.rx_mode = dsps_readl(mbase, wrp->rx_mode);
894 
895 	return 0;
896 }
897 
898 static int dsps_resume(struct device *dev)
899 {
900 	struct dsps_glue *glue = dev_get_drvdata(dev);
901 	const struct dsps_musb_wrapper *wrp = glue->wrp;
902 	struct musb *musb = platform_get_drvdata(glue->musb);
903 	void __iomem *mbase;
904 
905 	if (!musb)
906 		return 0;
907 
908 	mbase = musb->ctrl_base;
909 	dsps_writel(mbase, wrp->control, glue->context.control);
910 	dsps_writel(mbase, wrp->epintr_set, glue->context.epintr);
911 	dsps_writel(mbase, wrp->coreintr_set, glue->context.coreintr);
912 	dsps_writel(mbase, wrp->phy_utmi, glue->context.phy_utmi);
913 	dsps_writel(mbase, wrp->mode, glue->context.mode);
914 	dsps_writel(mbase, wrp->tx_mode, glue->context.tx_mode);
915 	dsps_writel(mbase, wrp->rx_mode, glue->context.rx_mode);
916 	if (musb->xceiv->otg->state == OTG_STATE_B_IDLE &&
917 	    musb->port_mode == MUSB_PORT_MODE_DUAL_ROLE)
918 		mod_timer(&glue->timer, jiffies +
919 				msecs_to_jiffies(wrp->poll_timeout));
920 
921 	return 0;
922 }
923 #endif
924 
925 static SIMPLE_DEV_PM_OPS(dsps_pm_ops, dsps_suspend, dsps_resume);
926 
927 static struct platform_driver dsps_usbss_driver = {
928 	.probe		= dsps_probe,
929 	.remove         = dsps_remove,
930 	.driver         = {
931 		.name   = "musb-dsps",
932 		.pm	= &dsps_pm_ops,
933 		.of_match_table	= musb_dsps_of_match,
934 	},
935 };
936 
937 MODULE_DESCRIPTION("TI DSPS MUSB Glue Layer");
938 MODULE_AUTHOR("Ravi B <ravibabu@ti.com>");
939 MODULE_AUTHOR("Ajay Kumar Gupta <ajay.gupta@ti.com>");
940 MODULE_LICENSE("GPL v2");
941 
942 module_platform_driver(dsps_usbss_driver);
943