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  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2005-2006 by Texas Instruments
  4 *
  5 * This file is part of the Inventra Controller Driver for Linux.
  6 */
  7
  8#include <linux/module.h>
  9#include <linux/kernel.h>
 10#include <linux/sched.h>
 11#include <linux/list.h>
 12#include <linux/delay.h>
 13#include <linux/clk.h>
 14#include <linux/err.h>
 15#include <linux/io.h>
 16#include <linux/gpio/consumer.h>
 17#include <linux/platform_device.h>
 18#include <linux/dma-mapping.h>
 19#include <linux/usb/usb_phy_generic.h>
 20
 21#include <mach/cputype.h>
 22#include <mach/hardware.h>
 23
 24#include <asm/mach-types.h>
 25
 26#include "musb_core.h"
 27
 28#include "davinci.h"
 29#include "cppi_dma.h"
 30
 31
 32#define USB_PHY_CTRL	IO_ADDRESS(USBPHY_CTL_PADDR)
 33#define DM355_DEEPSLEEP	IO_ADDRESS(DM355_DEEPSLEEP_PADDR)
 34
 35struct davinci_glue {
 36	struct device		*dev;
 37	struct platform_device	*musb;
 38	struct clk		*clk;
 39	bool			vbus_state;
 40	struct gpio_desc	*vbus;
 41	struct work_struct	vbus_work;
 42};
 43
 44/* REVISIT (PM) we should be able to keep the PHY in low power mode most
 45 * of the time (24 MHZ oscillator and PLL off, etc) by setting POWER.D0
 46 * and, when in host mode, autosuspending idle root ports... PHYPLLON
 47 * (overriding SUSPENDM?) then likely needs to stay off.
 48 */
 49
 50static inline void phy_on(void)
 51{
 52	u32	phy_ctrl = __raw_readl(USB_PHY_CTRL);
 53
 54	/* power everything up; start the on-chip PHY and its PLL */
 55	phy_ctrl &= ~(USBPHY_OSCPDWN | USBPHY_OTGPDWN | USBPHY_PHYPDWN);
 56	phy_ctrl |= USBPHY_SESNDEN | USBPHY_VBDTCTEN | USBPHY_PHYPLLON;
 57	__raw_writel(phy_ctrl, USB_PHY_CTRL);
 58
 59	/* wait for PLL to lock before proceeding */
 60	while ((__raw_readl(USB_PHY_CTRL) & USBPHY_PHYCLKGD) == 0)
 61		cpu_relax();
 62}
 63
 64static inline void phy_off(void)
 65{
 66	u32	phy_ctrl = __raw_readl(USB_PHY_CTRL);
 67
 68	/* powerdown the on-chip PHY, its PLL, and the OTG block */
 69	phy_ctrl &= ~(USBPHY_SESNDEN | USBPHY_VBDTCTEN | USBPHY_PHYPLLON);
 70	phy_ctrl |= USBPHY_OSCPDWN | USBPHY_OTGPDWN | USBPHY_PHYPDWN;
 71	__raw_writel(phy_ctrl, USB_PHY_CTRL);
 72}
 73
 74static int dma_off = 1;
 75
 76static void davinci_musb_enable(struct musb *musb)
 77{
 78	u32	tmp, old, val;
 79
 80	/* workaround:  setup irqs through both register sets */
 81	tmp = (musb->epmask & DAVINCI_USB_TX_ENDPTS_MASK)
 82			<< DAVINCI_USB_TXINT_SHIFT;
 83	musb_writel(musb->ctrl_base, DAVINCI_USB_INT_MASK_SET_REG, tmp);
 84	old = tmp;
 85	tmp = (musb->epmask & (0xfffe & DAVINCI_USB_RX_ENDPTS_MASK))
 86			<< DAVINCI_USB_RXINT_SHIFT;
 87	musb_writel(musb->ctrl_base, DAVINCI_USB_INT_MASK_SET_REG, tmp);
 88	tmp |= old;
 89
 90	val = ~MUSB_INTR_SOF;
 91	tmp |= ((val & 0x01ff) << DAVINCI_USB_USBINT_SHIFT);
 92	musb_writel(musb->ctrl_base, DAVINCI_USB_INT_MASK_SET_REG, tmp);
 93
 94	if (is_dma_capable() && !dma_off)
 95		printk(KERN_WARNING "%s %s: dma not reactivated\n",
 96				__FILE__, __func__);
 97	else
 98		dma_off = 0;
 99
100	/* force a DRVVBUS irq so we can start polling for ID change */
101	musb_writel(musb->ctrl_base, DAVINCI_USB_INT_SET_REG,
102			DAVINCI_INTR_DRVVBUS << DAVINCI_USB_USBINT_SHIFT);
103}
104
105/*
106 * Disable the HDRC and flush interrupts
107 */
108static void davinci_musb_disable(struct musb *musb)
109{
110	/* because we don't set CTRLR.UINT, "important" to:
111	 *  - not read/write INTRUSB/INTRUSBE
112	 *  - (except during initial setup, as workaround)
113	 *  - use INTSETR/INTCLRR instead
114	 */
115	musb_writel(musb->ctrl_base, DAVINCI_USB_INT_MASK_CLR_REG,
116			  DAVINCI_USB_USBINT_MASK
117			| DAVINCI_USB_TXINT_MASK
118			| DAVINCI_USB_RXINT_MASK);
119	musb_writel(musb->ctrl_base, DAVINCI_USB_EOI_REG, 0);
120
121	if (is_dma_capable() && !dma_off)
122		WARNING("dma still active\n");
123}
124
125
126#define	portstate(stmt)		stmt
127
128/*
129 * VBUS SWITCHING IS BOARD-SPECIFIC ... at least for the DM6446 EVM,
130 * which doesn't wire DRVVBUS to the FET that switches it.  Unclear
131 * if that's a problem with the DM6446 chip or just with that board.
132 *
133 * In either case, the DM355 EVM automates DRVVBUS the normal way,
134 * when J10 is out, and TI documents it as handling OTG.
135 */
136
137/* I2C operations are always synchronous, and require a task context.
138 * With unloaded systems, using the shared workqueue seems to suffice
139 * to satisfy the 100msec A_WAIT_VRISE timeout...
140 */
141static void evm_deferred_drvvbus(struct work_struct *work)
142{
143	struct davinci_glue *glue = container_of(work, struct davinci_glue,
144						 vbus_work);
145
146	gpiod_set_value_cansleep(glue->vbus, glue->vbus_state);
147	glue->vbus_state = !glue->vbus_state;
148}
149
150static void davinci_musb_source_power(struct musb *musb, int is_on,
151				      int immediate)
152{
153	struct davinci_glue *glue = dev_get_drvdata(musb->controller->parent);
154
155	/* This GPIO handling is entirely optional */
156	if (!glue->vbus)
157		return;
158
159	if (is_on)
160		is_on = 1;
161
162	if (glue->vbus_state == is_on)
163		return;
164	/* 0/1 vs "-1 == unknown/init" */
165	glue->vbus_state = !is_on;
166
167	if (machine_is_davinci_evm()) {
168		if (immediate)
169			gpiod_set_value_cansleep(glue->vbus, glue->vbus_state);
170		else
171			schedule_work(&glue->vbus_work);
172	}
173	if (immediate)
174		glue->vbus_state = is_on;
175}
176
177static void davinci_musb_set_vbus(struct musb *musb, int is_on)
178{
179	WARN_ON(is_on && is_peripheral_active(musb));
180	davinci_musb_source_power(musb, is_on, 0);
181}
182
183
184#define	POLL_SECONDS	2
185
186static void otg_timer(struct timer_list *t)
187{
188	struct musb		*musb = from_timer(musb, t, dev_timer);
189	void __iomem		*mregs = musb->mregs;
190	u8			devctl;
191	unsigned long		flags;
192
193	/* We poll because DaVinci's won't expose several OTG-critical
194	* status change events (from the transceiver) otherwise.
195	 */
196	devctl = musb_readb(mregs, MUSB_DEVCTL);
197	dev_dbg(musb->controller, "poll devctl %02x (%s)\n", devctl,
198		usb_otg_state_string(musb->xceiv->otg->state));
199
200	spin_lock_irqsave(&musb->lock, flags);
201	switch (musb->xceiv->otg->state) {
202	case OTG_STATE_A_WAIT_VFALL:
203		/* Wait till VBUS falls below SessionEnd (~0.2V); the 1.3 RTL
204		 * seems to mis-handle session "start" otherwise (or in our
205		 * case "recover"), in routine "VBUS was valid by the time
206		 * VBUSERR got reported during enumeration" cases.
207		 */
208		if (devctl & MUSB_DEVCTL_VBUS) {
209			mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
210			break;
211		}
212		musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
213		musb_writel(musb->ctrl_base, DAVINCI_USB_INT_SET_REG,
214			MUSB_INTR_VBUSERROR << DAVINCI_USB_USBINT_SHIFT);
215		break;
216	case OTG_STATE_B_IDLE:
217		/*
218		 * There's no ID-changed IRQ, so we have no good way to tell
219		 * when to switch to the A-Default state machine (by setting
220		 * the DEVCTL.SESSION flag).
221		 *
222		 * Workaround:  whenever we're in B_IDLE, try setting the
223		 * session flag every few seconds.  If it works, ID was
224		 * grounded and we're now in the A-Default state machine.
225		 *
226		 * NOTE setting the session flag is _supposed_ to trigger
227		 * SRP, but clearly it doesn't.
228		 */
229		musb_writeb(mregs, MUSB_DEVCTL,
230				devctl | MUSB_DEVCTL_SESSION);
231		devctl = musb_readb(mregs, MUSB_DEVCTL);
232		if (devctl & MUSB_DEVCTL_BDEVICE)
233			mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
234		else
235			musb->xceiv->otg->state = OTG_STATE_A_IDLE;
236		break;
237	default:
238		break;
239	}
240	spin_unlock_irqrestore(&musb->lock, flags);
241}
242
243static irqreturn_t davinci_musb_interrupt(int irq, void *__hci)
244{
245	unsigned long	flags;
246	irqreturn_t	retval = IRQ_NONE;
247	struct musb	*musb = __hci;
248	struct usb_otg	*otg = musb->xceiv->otg;
249	void __iomem	*tibase = musb->ctrl_base;
250	struct cppi	*cppi;
251	u32		tmp;
252
253	spin_lock_irqsave(&musb->lock, flags);
254
255	/* NOTE: DaVinci shadows the Mentor IRQs.  Don't manage them through
256	 * the Mentor registers (except for setup), use the TI ones and EOI.
257	 *
258	 * Docs describe irq "vector" registers associated with the CPPI and
259	 * USB EOI registers.  These hold a bitmask corresponding to the
260	 * current IRQ, not an irq handler address.  Would using those bits
261	 * resolve some of the races observed in this dispatch code??
262	 */
263
264	/* CPPI interrupts share the same IRQ line, but have their own
265	 * mask, state, "vector", and EOI registers.
266	 */
267	cppi = container_of(musb->dma_controller, struct cppi, controller);
268	if (is_cppi_enabled(musb) && musb->dma_controller && !cppi->irq)
269		retval = cppi_interrupt(irq, __hci);
270
271	/* ack and handle non-CPPI interrupts */
272	tmp = musb_readl(tibase, DAVINCI_USB_INT_SRC_MASKED_REG);
273	musb_writel(tibase, DAVINCI_USB_INT_SRC_CLR_REG, tmp);
274	dev_dbg(musb->controller, "IRQ %08x\n", tmp);
275
276	musb->int_rx = (tmp & DAVINCI_USB_RXINT_MASK)
277			>> DAVINCI_USB_RXINT_SHIFT;
278	musb->int_tx = (tmp & DAVINCI_USB_TXINT_MASK)
279			>> DAVINCI_USB_TXINT_SHIFT;
280	musb->int_usb = (tmp & DAVINCI_USB_USBINT_MASK)
281			>> DAVINCI_USB_USBINT_SHIFT;
282
283	/* DRVVBUS irqs are the only proxy we have (a very poor one!) for
284	 * DaVinci's missing ID change IRQ.  We need an ID change IRQ to
285	 * switch appropriately between halves of the OTG state machine.
286	 * Managing DEVCTL.SESSION per Mentor docs requires we know its
287	 * value, but DEVCTL.BDEVICE is invalid without DEVCTL.SESSION set.
288	 * Also, DRVVBUS pulses for SRP (but not at 5V) ...
289	 */
290	if (tmp & (DAVINCI_INTR_DRVVBUS << DAVINCI_USB_USBINT_SHIFT)) {
291		int	drvvbus = musb_readl(tibase, DAVINCI_USB_STAT_REG);
292		void __iomem *mregs = musb->mregs;
293		u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
294		int	err = musb->int_usb & MUSB_INTR_VBUSERROR;
295
296		err = musb->int_usb & MUSB_INTR_VBUSERROR;
297		if (err) {
298			/* The Mentor core doesn't debounce VBUS as needed
299			 * to cope with device connect current spikes. This
300			 * means it's not uncommon for bus-powered devices
301			 * to get VBUS errors during enumeration.
302			 *
303			 * This is a workaround, but newer RTL from Mentor
304			 * seems to allow a better one: "re"starting sessions
305			 * without waiting (on EVM, a **long** time) for VBUS
306			 * to stop registering in devctl.
307			 */
308			musb->int_usb &= ~MUSB_INTR_VBUSERROR;
309			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VFALL;
310			mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
311			WARNING("VBUS error workaround (delay coming)\n");
312		} else if (drvvbus) {
313			MUSB_HST_MODE(musb);
314			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
315			portstate(musb->port1_status |= USB_PORT_STAT_POWER);
316			del_timer(&musb->dev_timer);
317		} else {
318			musb->is_active = 0;
319			MUSB_DEV_MODE(musb);
320			musb->xceiv->otg->state = OTG_STATE_B_IDLE;
321			portstate(musb->port1_status &= ~USB_PORT_STAT_POWER);
322		}
323
324		/* NOTE:  this must complete poweron within 100 msec
325		 * (OTG_TIME_A_WAIT_VRISE) but we don't check for that.
326		 */
327		davinci_musb_source_power(musb, drvvbus, 0);
328		dev_dbg(musb->controller, "VBUS %s (%s)%s, devctl %02x\n",
329				drvvbus ? "on" : "off",
330				usb_otg_state_string(musb->xceiv->otg->state),
331				err ? " ERROR" : "",
332				devctl);
333		retval = IRQ_HANDLED;
334	}
335
336	if (musb->int_tx || musb->int_rx || musb->int_usb)
337		retval |= musb_interrupt(musb);
338
339	/* irq stays asserted until EOI is written */
340	musb_writel(tibase, DAVINCI_USB_EOI_REG, 0);
341
342	/* poll for ID change */
343	if (musb->xceiv->otg->state == OTG_STATE_B_IDLE)
344		mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
345
346	spin_unlock_irqrestore(&musb->lock, flags);
347
348	return retval;
349}
350
351static int davinci_musb_set_mode(struct musb *musb, u8 mode)
352{
353	/* EVM can't do this (right?) */
354	return -EIO;
355}
356
357static int davinci_musb_init(struct musb *musb)
358{
359	void __iomem	*tibase = musb->ctrl_base;
360	u32		revision;
361	int 		ret = -ENODEV;
362
363	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
364	if (IS_ERR_OR_NULL(musb->xceiv)) {
365		ret = -EPROBE_DEFER;
366		goto unregister;
367	}
368
369	musb->mregs += DAVINCI_BASE_OFFSET;
370
371	/* returns zero if e.g. not clocked */
372	revision = musb_readl(tibase, DAVINCI_USB_VERSION_REG);
373	if (revision == 0)
374		goto fail;
375
376	timer_setup(&musb->dev_timer, otg_timer, 0);
377
378	davinci_musb_source_power(musb, 0, 1);
379
380	/* dm355 EVM swaps D+/D- for signal integrity, and
381	 * is clocked from the main 24 MHz crystal.
382	 */
383	if (machine_is_davinci_dm355_evm()) {
384		u32	phy_ctrl = __raw_readl(USB_PHY_CTRL);
385
386		phy_ctrl &= ~(3 << 9);
387		phy_ctrl |= USBPHY_DATAPOL;
388		__raw_writel(phy_ctrl, USB_PHY_CTRL);
389	}
390
391	/* On dm355, the default-A state machine needs DRVVBUS control.
392	 * If we won't be a host, there's no need to turn it on.
393	 */
394	if (cpu_is_davinci_dm355()) {
395		u32	deepsleep = __raw_readl(DM355_DEEPSLEEP);
396
397		deepsleep &= ~DRVVBUS_FORCE;
398		__raw_writel(deepsleep, DM355_DEEPSLEEP);
399	}
400
401	/* reset the controller */
402	musb_writel(tibase, DAVINCI_USB_CTRL_REG, 0x1);
403
404	/* start the on-chip PHY and its PLL */
405	phy_on();
406
407	msleep(5);
408
409	/* NOTE:  irqs are in mixed mode, not bypass to pure-musb */
410	pr_debug("DaVinci OTG revision %08x phy %03x control %02x\n",
411		revision, __raw_readl(USB_PHY_CTRL),
412		musb_readb(tibase, DAVINCI_USB_CTRL_REG));
413
414	musb->isr = davinci_musb_interrupt;
415	return 0;
416
417fail:
418	usb_put_phy(musb->xceiv);
419unregister:
420	usb_phy_generic_unregister();
421	return ret;
422}
423
424static int davinci_musb_exit(struct musb *musb)
425{
426	int	maxdelay = 30;
427	u8	devctl, warn = 0;
428
429	del_timer_sync(&musb->dev_timer);
430
431	/* force VBUS off */
432	if (cpu_is_davinci_dm355()) {
433		u32	deepsleep = __raw_readl(DM355_DEEPSLEEP);
434
435		deepsleep &= ~DRVVBUS_FORCE;
436		deepsleep |= DRVVBUS_OVERRIDE;
437		__raw_writel(deepsleep, DM355_DEEPSLEEP);
438	}
439
440	davinci_musb_source_power(musb, 0 /*off*/, 1);
441
442	/*
443	 * delay, to avoid problems with module reload.
444	 * if there's no peripheral connected, this can take a
445	 * long time to fall, especially on EVM with huge C133.
446	 */
447	do {
448		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
449		if (!(devctl & MUSB_DEVCTL_VBUS))
450			break;
451		if ((devctl & MUSB_DEVCTL_VBUS) != warn) {
452			warn = devctl & MUSB_DEVCTL_VBUS;
453			dev_dbg(musb->controller, "VBUS %d\n",
454				warn >> MUSB_DEVCTL_VBUS_SHIFT);
455		}
456		msleep(1000);
457		maxdelay--;
458	} while (maxdelay > 0);
459
460	/* in OTG mode, another host might be connected */
461	if (devctl & MUSB_DEVCTL_VBUS)
462		dev_dbg(musb->controller, "VBUS off timeout (devctl %02x)\n", devctl);
463
464	phy_off();
465
466	usb_put_phy(musb->xceiv);
467
468	return 0;
469}
470
471static const struct musb_platform_ops davinci_ops = {
472	.quirks		= MUSB_DMA_CPPI,
473	.init		= davinci_musb_init,
474	.exit		= davinci_musb_exit,
475
476#ifdef CONFIG_USB_TI_CPPI_DMA
477	.dma_init	= cppi_dma_controller_create,
478	.dma_exit	= cppi_dma_controller_destroy,
479#endif
480	.enable		= davinci_musb_enable,
481	.disable	= davinci_musb_disable,
482
483	.set_mode	= davinci_musb_set_mode,
484
485	.set_vbus	= davinci_musb_set_vbus,
486};
487
488static const struct platform_device_info davinci_dev_info = {
489	.name		= "musb-hdrc",
490	.id		= PLATFORM_DEVID_AUTO,
491	.dma_mask	= DMA_BIT_MASK(32),
492};
493
494static int davinci_probe(struct platform_device *pdev)
495{
496	struct resource			musb_resources[3];
497	struct musb_hdrc_platform_data	*pdata = dev_get_platdata(&pdev->dev);
498	struct platform_device		*musb;
499	struct davinci_glue		*glue;
500	struct platform_device_info	pinfo;
501	struct clk			*clk;
502
503	int				ret = -ENOMEM;
504
505	glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
506	if (!glue)
507		goto err0;
508
509	clk = devm_clk_get(&pdev->dev, "usb");
510	if (IS_ERR(clk)) {
511		dev_err(&pdev->dev, "failed to get clock\n");
512		ret = PTR_ERR(clk);
513		goto err0;
514	}
515
516	ret = clk_enable(clk);
517	if (ret) {
518		dev_err(&pdev->dev, "failed to enable clock\n");
519		goto err0;
520	}
521
522	glue->dev			= &pdev->dev;
523	glue->clk			= clk;
524
525	pdata->platform_ops		= &davinci_ops;
526
527	glue->vbus = devm_gpiod_get_optional(&pdev->dev, NULL, GPIOD_OUT_LOW);
528	if (IS_ERR(glue->vbus)) {
529		ret = PTR_ERR(glue->vbus);
530		goto err0;
531	} else {
532		glue->vbus_state = -1;
533		INIT_WORK(&glue->vbus_work, evm_deferred_drvvbus);
534	}
535
536	usb_phy_generic_register();
537	platform_set_drvdata(pdev, glue);
538
539	memset(musb_resources, 0x00, sizeof(*musb_resources) *
540			ARRAY_SIZE(musb_resources));
541
542	musb_resources[0].name = pdev->resource[0].name;
543	musb_resources[0].start = pdev->resource[0].start;
544	musb_resources[0].end = pdev->resource[0].end;
545	musb_resources[0].flags = pdev->resource[0].flags;
546
547	musb_resources[1].name = pdev->resource[1].name;
548	musb_resources[1].start = pdev->resource[1].start;
549	musb_resources[1].end = pdev->resource[1].end;
550	musb_resources[1].flags = pdev->resource[1].flags;
551
552	/*
553	 * For DM6467 3 resources are passed. A placeholder for the 3rd
554	 * resource is always there, so it's safe to always copy it...
555	 */
556	musb_resources[2].name = pdev->resource[2].name;
557	musb_resources[2].start = pdev->resource[2].start;
558	musb_resources[2].end = pdev->resource[2].end;
559	musb_resources[2].flags = pdev->resource[2].flags;
560
561	pinfo = davinci_dev_info;
562	pinfo.parent = &pdev->dev;
563	pinfo.res = musb_resources;
564	pinfo.num_res = ARRAY_SIZE(musb_resources);
565	pinfo.data = pdata;
566	pinfo.size_data = sizeof(*pdata);
567
568	glue->musb = musb = platform_device_register_full(&pinfo);
569	if (IS_ERR(musb)) {
570		ret = PTR_ERR(musb);
571		dev_err(&pdev->dev, "failed to register musb device: %d\n", ret);
572		goto err1;
573	}
574
575	return 0;
576
577err1:
578	clk_disable(clk);
579
580err0:
581	return ret;
582}
583
584static int davinci_remove(struct platform_device *pdev)
585{
586	struct davinci_glue		*glue = platform_get_drvdata(pdev);
587
588	platform_device_unregister(glue->musb);
589	usb_phy_generic_unregister();
590	clk_disable(glue->clk);
591
592	return 0;
593}
594
595static struct platform_driver davinci_driver = {
596	.probe		= davinci_probe,
597	.remove		= davinci_remove,
598	.driver		= {
599		.name	= "musb-davinci",
600	},
601};
602
603MODULE_DESCRIPTION("DaVinci MUSB Glue Layer");
604MODULE_AUTHOR("Felipe Balbi <balbi@ti.com>");
605MODULE_LICENSE("GPL v2");
606module_platform_driver(davinci_driver);