1
2/*
3 * Texas Instruments AM35x "glue layer"
4 *
5 * Copyright (c) 2010, by Texas Instruments
6 *
7 * Based on the DA8xx "glue layer" code.
8 * Copyright (c) 2008-2009, MontaVista Software, Inc. <source@mvista.com>
9 *
10 * This file is part of the Inventra Controller Driver for Linux.
11 *
12 * The Inventra Controller Driver for Linux is free software; you
13 * can redistribute it and/or modify it under the terms of the GNU
14 * General Public License version 2 as published by the Free Software
15 * Foundation.
16 *
17 * The Inventra Controller Driver for Linux is distributed in
18 * the hope that it will be useful, but WITHOUT ANY WARRANTY;
19 * without even the implied warranty of MERCHANTABILITY or
20 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
21 * License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with The Inventra Controller Driver for Linux ; if not,
25 * write to the Free Software Foundation, Inc., 59 Temple Place,
26 * Suite 330, Boston, MA  02111-1307  USA
27 *
28 */
29
30#include <linux/module.h>
31#include <linux/clk.h>
32#include <linux/err.h>
33#include <linux/io.h>
34#include <linux/platform_device.h>
35#include <linux/dma-mapping.h>
36#include <linux/usb/usb_phy_generic.h>
37#include <linux/platform_data/usb-omap.h>
38
39#include "musb_core.h"
40
41/*
42 * AM35x specific definitions
43 */
44/* USB 2.0 OTG module registers */
45#define USB_REVISION_REG	0x00
46#define USB_CTRL_REG		0x04
47#define USB_STAT_REG		0x08
48#define USB_EMULATION_REG	0x0c
49/* 0x10 Reserved */
50#define USB_AUTOREQ_REG		0x14
51#define USB_SRP_FIX_TIME_REG	0x18
52#define USB_TEARDOWN_REG	0x1c
53#define EP_INTR_SRC_REG		0x20
54#define EP_INTR_SRC_SET_REG	0x24
55#define EP_INTR_SRC_CLEAR_REG	0x28
56#define EP_INTR_MASK_REG	0x2c
57#define EP_INTR_MASK_SET_REG	0x30
58#define EP_INTR_MASK_CLEAR_REG	0x34
59#define EP_INTR_SRC_MASKED_REG	0x38
60#define CORE_INTR_SRC_REG	0x40
61#define CORE_INTR_SRC_SET_REG	0x44
62#define CORE_INTR_SRC_CLEAR_REG	0x48
63#define CORE_INTR_MASK_REG	0x4c
64#define CORE_INTR_MASK_SET_REG	0x50
65#define CORE_INTR_MASK_CLEAR_REG 0x54
66#define CORE_INTR_SRC_MASKED_REG 0x58
67/* 0x5c Reserved */
68#define USB_END_OF_INTR_REG	0x60
69
70/* Control register bits */
71#define AM35X_SOFT_RESET_MASK	1
72
73/* USB interrupt register bits */
74#define AM35X_INTR_USB_SHIFT	16
75#define AM35X_INTR_USB_MASK	(0x1ff << AM35X_INTR_USB_SHIFT)
76#define AM35X_INTR_DRVVBUS	0x100
77#define AM35X_INTR_RX_SHIFT	16
78#define AM35X_INTR_TX_SHIFT	0
79#define AM35X_TX_EP_MASK	0xffff		/* EP0 + 15 Tx EPs */
80#define AM35X_RX_EP_MASK	0xfffe		/* 15 Rx EPs */
81#define AM35X_TX_INTR_MASK	(AM35X_TX_EP_MASK << AM35X_INTR_TX_SHIFT)
82#define AM35X_RX_INTR_MASK	(AM35X_RX_EP_MASK << AM35X_INTR_RX_SHIFT)
83
84#define USB_MENTOR_CORE_OFFSET	0x400
85
86struct am35x_glue {
87	struct device		*dev;
88	struct platform_device	*musb;
89	struct platform_device	*phy;
90	struct clk		*phy_clk;
91	struct clk		*clk;
92};
93
94/*
95 * am35x_musb_enable - enable interrupts
96 */
97static void am35x_musb_enable(struct musb *musb)
98{
99	void __iomem *reg_base = musb->ctrl_base;
100	u32 epmask;
101
102	/* Workaround: setup IRQs through both register sets. */
103	epmask = ((musb->epmask & AM35X_TX_EP_MASK) << AM35X_INTR_TX_SHIFT) |
104	       ((musb->epmask & AM35X_RX_EP_MASK) << AM35X_INTR_RX_SHIFT);
105
106	musb_writel(reg_base, EP_INTR_MASK_SET_REG, epmask);
107	musb_writel(reg_base, CORE_INTR_MASK_SET_REG, AM35X_INTR_USB_MASK);
108
109	/* Force the DRVVBUS IRQ so we can start polling for ID change. */
110	musb_writel(reg_base, CORE_INTR_SRC_SET_REG,
111			AM35X_INTR_DRVVBUS << AM35X_INTR_USB_SHIFT);
112}
113
114/*
115 * am35x_musb_disable - disable HDRC and flush interrupts
116 */
117static void am35x_musb_disable(struct musb *musb)
118{
119	void __iomem *reg_base = musb->ctrl_base;
120
121	musb_writel(reg_base, CORE_INTR_MASK_CLEAR_REG, AM35X_INTR_USB_MASK);
122	musb_writel(reg_base, EP_INTR_MASK_CLEAR_REG,
123			 AM35X_TX_INTR_MASK | AM35X_RX_INTR_MASK);
124	musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
125	musb_writel(reg_base, USB_END_OF_INTR_REG, 0);
126}
127
128#define portstate(stmt)		stmt
129
130static void am35x_musb_set_vbus(struct musb *musb, int is_on)
131{
132	WARN_ON(is_on && is_peripheral_active(musb));
133}
134
135#define	POLL_SECONDS	2
136
137static struct timer_list otg_workaround;
138
139static void otg_timer(unsigned long _musb)
140{
141	struct musb		*musb = (void *)_musb;
142	void __iomem		*mregs = musb->mregs;
143	u8			devctl;
144	unsigned long		flags;
145
146	/*
147	 * We poll because AM35x's won't expose several OTG-critical
148	 * status change events (from the transceiver) otherwise.
149	 */
150	devctl = musb_readb(mregs, MUSB_DEVCTL);
151	dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl,
152		usb_otg_state_string(musb->xceiv->otg->state));
153
154	spin_lock_irqsave(&musb->lock, flags);
155	switch (musb->xceiv->otg->state) {
156	case OTG_STATE_A_WAIT_BCON:
157		devctl &= ~MUSB_DEVCTL_SESSION;
158		musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
159
160		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
161		if (devctl & MUSB_DEVCTL_BDEVICE) {
162			musb->xceiv->otg->state = OTG_STATE_B_IDLE;
163			MUSB_DEV_MODE(musb);
164		} else {
165			musb->xceiv->otg->state = OTG_STATE_A_IDLE;
166			MUSB_HST_MODE(musb);
167		}
168		break;
169	case OTG_STATE_A_WAIT_VFALL:
170		musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
171		musb_writel(musb->ctrl_base, CORE_INTR_SRC_SET_REG,
172			    MUSB_INTR_VBUSERROR << AM35X_INTR_USB_SHIFT);
173		break;
174	case OTG_STATE_B_IDLE:
175		devctl = musb_readb(mregs, MUSB_DEVCTL);
176		if (devctl & MUSB_DEVCTL_BDEVICE)
177			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
178		else
179			musb->xceiv->otg->state = OTG_STATE_A_IDLE;
180		break;
181	default:
182		break;
183	}
184	spin_unlock_irqrestore(&musb->lock, flags);
185}
186
187static void am35x_musb_try_idle(struct musb *musb, unsigned long timeout)
188{
189	static unsigned long last_timer;
190
191	if (timeout == 0)
192		timeout = jiffies + msecs_to_jiffies(3);
193
194	/* Never idle if active, or when VBUS timeout is not set as host */
195	if (musb->is_active || (musb->a_wait_bcon == 0 &&
196				musb->xceiv->otg->state == OTG_STATE_A_WAIT_BCON)) {
197		dev_dbg(musb->controller, "%s active, deleting timer\n",
198			usb_otg_state_string(musb->xceiv->otg->state));
199		del_timer(&otg_workaround);
200		last_timer = jiffies;
201		return;
202	}
203
204	if (time_after(last_timer, timeout) && timer_pending(&otg_workaround)) {
205		dev_dbg(musb->controller, "Longer idle timer already pending, ignoring...\n");
206		return;
207	}
208	last_timer = timeout;
209
210	dev_dbg(musb->controller, "%s inactive, starting idle timer for %u ms\n",
211		usb_otg_state_string(musb->xceiv->otg->state),
212		jiffies_to_msecs(timeout - jiffies));
213	mod_timer(&otg_workaround, timeout);
214}
215
216static irqreturn_t am35x_musb_interrupt(int irq, void *hci)
217{
218	struct musb  *musb = hci;
219	void __iomem *reg_base = musb->ctrl_base;
220	struct device *dev = musb->controller;
221	struct musb_hdrc_platform_data *plat = dev_get_platdata(dev);
222	struct omap_musb_board_data *data = plat->board_data;
223	struct usb_otg *otg = musb->xceiv->otg;
224	unsigned long flags;
225	irqreturn_t ret = IRQ_NONE;
226	u32 epintr, usbintr;
227
228	spin_lock_irqsave(&musb->lock, flags);
229
230	/* Get endpoint interrupts */
231	epintr = musb_readl(reg_base, EP_INTR_SRC_MASKED_REG);
232
233	if (epintr) {
234		musb_writel(reg_base, EP_INTR_SRC_CLEAR_REG, epintr);
235
236		musb->int_rx =
237			(epintr & AM35X_RX_INTR_MASK) >> AM35X_INTR_RX_SHIFT;
238		musb->int_tx =
239			(epintr & AM35X_TX_INTR_MASK) >> AM35X_INTR_TX_SHIFT;
240	}
241
242	/* Get usb core interrupts */
243	usbintr = musb_readl(reg_base, CORE_INTR_SRC_MASKED_REG);
244	if (!usbintr && !epintr)
245		goto eoi;
246
247	if (usbintr) {
248		musb_writel(reg_base, CORE_INTR_SRC_CLEAR_REG, usbintr);
249
250		musb->int_usb =
251			(usbintr & AM35X_INTR_USB_MASK) >> AM35X_INTR_USB_SHIFT;
252	}
253	/*
254	 * DRVVBUS IRQs are the only proxy we have (a very poor one!) for
255	 * AM35x's missing ID change IRQ.  We need an ID change IRQ to
256	 * switch appropriately between halves of the OTG state machine.
257	 * Managing DEVCTL.SESSION per Mentor docs requires that we know its
258	 * value but DEVCTL.BDEVICE is invalid without DEVCTL.SESSION set.
259	 * Also, DRVVBUS pulses for SRP (but not at 5V) ...
260	 */
261	if (usbintr & (AM35X_INTR_DRVVBUS << AM35X_INTR_USB_SHIFT)) {
262		int drvvbus = musb_readl(reg_base, USB_STAT_REG);
263		void __iomem *mregs = musb->mregs;
264		u8 devctl = musb_readb(mregs, MUSB_DEVCTL);
265		int err;
266
267		err = musb->int_usb & MUSB_INTR_VBUSERROR;
268		if (err) {
269			/*
270			 * The Mentor core doesn't debounce VBUS as needed
271			 * to cope with device connect current spikes. This
272			 * means it's not uncommon for bus-powered devices
273			 * to get VBUS errors during enumeration.
274			 *
275			 * This is a workaround, but newer RTL from Mentor
276			 * seems to allow a better one: "re"-starting sessions
277			 * without waiting for VBUS to stop registering in
278			 * devctl.
279			 */
280			musb->int_usb &= ~MUSB_INTR_VBUSERROR;
281			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VFALL;
282			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
283			WARNING("VBUS error workaround (delay coming)\n");
284		} else if (drvvbus) {
285			MUSB_HST_MODE(musb);
286			otg->default_a = 1;
287			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
288			portstate(musb->port1_status |= USB_PORT_STAT_POWER);
289			del_timer(&otg_workaround);
290		} else {
291			musb->is_active = 0;
292			MUSB_DEV_MODE(musb);
293			otg->default_a = 0;
294			musb->xceiv->otg->state = OTG_STATE_B_IDLE;
295			portstate(musb->port1_status &= ~USB_PORT_STAT_POWER);
296		}
297
298		/* NOTE: this must complete power-on within 100 ms. */
299		dev_dbg(musb->controller, "VBUS %s (%s)%s, devctl %02x\n",
300				drvvbus ? "on" : "off",
301				usb_otg_state_string(musb->xceiv->otg->state),
302				err ? " ERROR" : "",
303				devctl);
304		ret = IRQ_HANDLED;
305	}
306
307	/* Drop spurious RX and TX if device is disconnected */
308	if (musb->int_usb & MUSB_INTR_DISCONNECT) {
309		musb->int_tx = 0;
310		musb->int_rx = 0;
311	}
312
313	if (musb->int_tx || musb->int_rx || musb->int_usb)
314		ret |= musb_interrupt(musb);
315
316eoi:
317	/* EOI needs to be written for the IRQ to be re-asserted. */
318	if (ret == IRQ_HANDLED || epintr || usbintr) {
319		/* clear level interrupt */
320		if (data->clear_irq)
321			data->clear_irq();
322		/* write EOI */
323		musb_writel(reg_base, USB_END_OF_INTR_REG, 0);
324	}
325
326	/* Poll for ID change */
327	if (musb->xceiv->otg->state == OTG_STATE_B_IDLE)
328		mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
329
330	spin_unlock_irqrestore(&musb->lock, flags);
331
332	return ret;
333}
334
335static int am35x_musb_set_mode(struct musb *musb, u8 musb_mode)
336{
337	struct device *dev = musb->controller;
338	struct musb_hdrc_platform_data *plat = dev_get_platdata(dev);
339	struct omap_musb_board_data *data = plat->board_data;
340	int     retval = 0;
341
342	if (data->set_mode)
343		data->set_mode(musb_mode);
344	else
345		retval = -EIO;
346
347	return retval;
348}
349
350static int am35x_musb_init(struct musb *musb)
351{
352	struct device *dev = musb->controller;
353	struct musb_hdrc_platform_data *plat = dev_get_platdata(dev);
354	struct omap_musb_board_data *data = plat->board_data;
355	void __iomem *reg_base = musb->ctrl_base;
356	u32 rev;
357
358	musb->mregs += USB_MENTOR_CORE_OFFSET;
359
360	/* Returns zero if e.g. not clocked */
361	rev = musb_readl(reg_base, USB_REVISION_REG);
362	if (!rev)
363		return -ENODEV;
364
365	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
366	if (IS_ERR_OR_NULL(musb->xceiv))
367		return -EPROBE_DEFER;
368
369	setup_timer(&otg_workaround, otg_timer, (unsigned long) musb);
370
371	/* Reset the musb */
372	if (data->reset)
373		data->reset();
374
375	/* Reset the controller */
376	musb_writel(reg_base, USB_CTRL_REG, AM35X_SOFT_RESET_MASK);
377
378	/* Start the on-chip PHY and its PLL. */
379	if (data->set_phy_power)
380		data->set_phy_power(1);
381
382	msleep(5);
383
384	musb->isr = am35x_musb_interrupt;
385
386	/* clear level interrupt */
387	if (data->clear_irq)
388		data->clear_irq();
389
390	return 0;
391}
392
393static int am35x_musb_exit(struct musb *musb)
394{
395	struct device *dev = musb->controller;
396	struct musb_hdrc_platform_data *plat = dev_get_platdata(dev);
397	struct omap_musb_board_data *data = plat->board_data;
398
399	del_timer_sync(&otg_workaround);
400
401	/* Shutdown the on-chip PHY and its PLL. */
402	if (data->set_phy_power)
403		data->set_phy_power(0);
404
405	usb_put_phy(musb->xceiv);
406
407	return 0;
408}
409
410/* AM35x supports only 32bit read operation */
411static void am35x_read_fifo(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
412{
413	void __iomem *fifo = hw_ep->fifo;
414	u32		val;
415	int		i;
416
417	/* Read for 32bit-aligned destination address */
418	if (likely((0x03 & (unsigned long) dst) == 0) && len >= 4) {
419		readsl(fifo, dst, len >> 2);
420		dst += len & ~0x03;
421		len &= 0x03;
422	}
423	/*
424	 * Now read the remaining 1 to 3 byte or complete length if
425	 * unaligned address.
426	 */
427	if (len > 4) {
428		for (i = 0; i < (len >> 2); i++) {
429			*(u32 *) dst = musb_readl(fifo, 0);
430			dst += 4;
431		}
432		len &= 0x03;
433	}
434	if (len > 0) {
435		val = musb_readl(fifo, 0);
436		memcpy(dst, &val, len);
437	}
438}
439
440static const struct musb_platform_ops am35x_ops = {
441	.quirks		= MUSB_DMA_INVENTRA | MUSB_INDEXED_EP,
442	.init		= am35x_musb_init,
443	.exit		= am35x_musb_exit,
444
445	.read_fifo	= am35x_read_fifo,
446#ifdef CONFIG_USB_INVENTRA_DMA
447	.dma_init	= musbhs_dma_controller_create,
448	.dma_exit	= musbhs_dma_controller_destroy,
449#endif
450	.enable		= am35x_musb_enable,
451	.disable	= am35x_musb_disable,
452
453	.set_mode	= am35x_musb_set_mode,
454	.try_idle	= am35x_musb_try_idle,
455
456	.set_vbus	= am35x_musb_set_vbus,
457};
458
459static const struct platform_device_info am35x_dev_info = {
460	.name		= "musb-hdrc",
461	.id		= PLATFORM_DEVID_AUTO,
462	.dma_mask	= DMA_BIT_MASK(32),
463};
464
465static int am35x_probe(struct platform_device *pdev)
466{
467	struct musb_hdrc_platform_data	*pdata = dev_get_platdata(&pdev->dev);
468	struct platform_device		*musb;
469	struct am35x_glue		*glue;
470	struct platform_device_info	pinfo;
471	struct clk			*phy_clk;
472	struct clk			*clk;
473
474	int				ret = -ENOMEM;
475
476	glue = kzalloc(sizeof(*glue), GFP_KERNEL);
477	if (!glue) {
478		dev_err(&pdev->dev, "failed to allocate glue context\n");
479		goto err0;
480	}
481
482	phy_clk = clk_get(&pdev->dev, "fck");
483	if (IS_ERR(phy_clk)) {
484		dev_err(&pdev->dev, "failed to get PHY clock\n");
485		ret = PTR_ERR(phy_clk);
486		goto err3;
487	}
488
489	clk = clk_get(&pdev->dev, "ick");
490	if (IS_ERR(clk)) {
491		dev_err(&pdev->dev, "failed to get clock\n");
492		ret = PTR_ERR(clk);
493		goto err4;
494	}
495
496	ret = clk_enable(phy_clk);
497	if (ret) {
498		dev_err(&pdev->dev, "failed to enable PHY clock\n");
499		goto err5;
500	}
501
502	ret = clk_enable(clk);
503	if (ret) {
504		dev_err(&pdev->dev, "failed to enable clock\n");
505		goto err6;
506	}
507
508	glue->dev			= &pdev->dev;
509	glue->phy_clk			= phy_clk;
510	glue->clk			= clk;
511
512	pdata->platform_ops		= &am35x_ops;
513
514	glue->phy = usb_phy_generic_register();
515	if (IS_ERR(glue->phy))
516		goto err7;
517	platform_set_drvdata(pdev, glue);
518
519	pinfo = am35x_dev_info;
520	pinfo.parent = &pdev->dev;
521	pinfo.res = pdev->resource;
522	pinfo.num_res = pdev->num_resources;
523	pinfo.data = pdata;
524	pinfo.size_data = sizeof(*pdata);
525
526	glue->musb = musb = platform_device_register_full(&pinfo);
527	if (IS_ERR(musb)) {
528		ret = PTR_ERR(musb);
529		dev_err(&pdev->dev, "failed to register musb device: %d\n", ret);
530		goto err8;
531	}
532
533	return 0;
534
535err8:
536	usb_phy_generic_unregister(glue->phy);
537
538err7:
539	clk_disable(clk);
540
541err6:
542	clk_disable(phy_clk);
543
544err5:
545	clk_put(clk);
546
547err4:
548	clk_put(phy_clk);
549
550err3:
551	kfree(glue);
552
553err0:
554	return ret;
555}
556
557static int am35x_remove(struct platform_device *pdev)
558{
559	struct am35x_glue	*glue = platform_get_drvdata(pdev);
560
561	platform_device_unregister(glue->musb);
562	usb_phy_generic_unregister(glue->phy);
563	clk_disable(glue->clk);
564	clk_disable(glue->phy_clk);
565	clk_put(glue->clk);
566	clk_put(glue->phy_clk);
567	kfree(glue);
568
569	return 0;
570}
571
572#ifdef CONFIG_PM_SLEEP
573static int am35x_suspend(struct device *dev)
574{
575	struct am35x_glue	*glue = dev_get_drvdata(dev);
576	struct musb_hdrc_platform_data *plat = dev_get_platdata(dev);
577	struct omap_musb_board_data *data = plat->board_data;
578
579	/* Shutdown the on-chip PHY and its PLL. */
580	if (data->set_phy_power)
581		data->set_phy_power(0);
582
583	clk_disable(glue->phy_clk);
584	clk_disable(glue->clk);
585
586	return 0;
587}
588
589static int am35x_resume(struct device *dev)
590{
591	struct am35x_glue	*glue = dev_get_drvdata(dev);
592	struct musb_hdrc_platform_data *plat = dev_get_platdata(dev);
593	struct omap_musb_board_data *data = plat->board_data;
594	int			ret;
595
596	/* Start the on-chip PHY and its PLL. */
597	if (data->set_phy_power)
598		data->set_phy_power(1);
599
600	ret = clk_enable(glue->phy_clk);
601	if (ret) {
602		dev_err(dev, "failed to enable PHY clock\n");
603		return ret;
604	}
605
606	ret = clk_enable(glue->clk);
607	if (ret) {
608		dev_err(dev, "failed to enable clock\n");
609		return ret;
610	}
611
612	return 0;
613}
614#endif
615
616static SIMPLE_DEV_PM_OPS(am35x_pm_ops, am35x_suspend, am35x_resume);
617
618static struct platform_driver am35x_driver = {
619	.probe		= am35x_probe,
620	.remove		= am35x_remove,
621	.driver		= {
622		.name	= "musb-am35x",
623		.pm	= &am35x_pm_ops,
624	},
625};
626
627MODULE_DESCRIPTION("AM35x MUSB Glue Layer");
628MODULE_AUTHOR("Ajay Kumar Gupta <ajay.gupta@ti.com>");
629MODULE_LICENSE("GPL v2");
630module_platform_driver(am35x_driver);
631