xref: /openbmc/linux/drivers/usb/musb/da8xx.c (revision e9839402)
1 /*
2  * Texas Instruments DA8xx/OMAP-L1x "glue layer"
3  *
4  * Copyright (c) 2008-2009 MontaVista Software, Inc. <source@mvista.com>
5  *
6  * Based on the DaVinci "glue layer" code.
7  * Copyright (C) 2005-2006 by Texas Instruments
8  *
9  * This file is part of the Inventra Controller Driver for Linux.
10  *
11  * The Inventra Controller Driver for Linux is free software; you
12  * can redistribute it and/or modify it under the terms of the GNU
13  * General Public License version 2 as published by the Free Software
14  * Foundation.
15  *
16  * The Inventra Controller Driver for Linux is distributed in
17  * the hope that it will be useful, but WITHOUT ANY WARRANTY;
18  * without even the implied warranty of MERCHANTABILITY or
19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
20  * License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with The Inventra Controller Driver for Linux ; if not,
24  * write to the Free Software Foundation, Inc., 59 Temple Place,
25  * Suite 330, Boston, MA  02111-1307  USA
26  *
27  */
28 
29 #include <linux/module.h>
30 #include <linux/clk.h>
31 #include <linux/err.h>
32 #include <linux/io.h>
33 #include <linux/phy/phy.h>
34 #include <linux/platform_device.h>
35 #include <linux/dma-mapping.h>
36 #include <linux/usb/usb_phy_generic.h>
37 
38 #include "musb_core.h"
39 
40 /*
41  * DA8XX specific definitions
42  */
43 
44 /* USB 2.0 OTG module registers */
45 #define DA8XX_USB_REVISION_REG	0x00
46 #define DA8XX_USB_CTRL_REG	0x04
47 #define DA8XX_USB_STAT_REG	0x08
48 #define DA8XX_USB_EMULATION_REG 0x0c
49 #define DA8XX_USB_MODE_REG	0x10	/* Transparent, CDC, [Generic] RNDIS */
50 #define DA8XX_USB_AUTOREQ_REG	0x14
51 #define DA8XX_USB_SRP_FIX_TIME_REG 0x18
52 #define DA8XX_USB_TEARDOWN_REG	0x1c
53 #define DA8XX_USB_INTR_SRC_REG	0x20
54 #define DA8XX_USB_INTR_SRC_SET_REG 0x24
55 #define DA8XX_USB_INTR_SRC_CLEAR_REG 0x28
56 #define DA8XX_USB_INTR_MASK_REG 0x2c
57 #define DA8XX_USB_INTR_MASK_SET_REG 0x30
58 #define DA8XX_USB_INTR_MASK_CLEAR_REG 0x34
59 #define DA8XX_USB_INTR_SRC_MASKED_REG 0x38
60 #define DA8XX_USB_END_OF_INTR_REG 0x3c
61 #define DA8XX_USB_GENERIC_RNDIS_EP_SIZE_REG(n) (0x50 + (((n) - 1) << 2))
62 
63 /* Control register bits */
64 #define DA8XX_SOFT_RESET_MASK	1
65 
66 #define DA8XX_USB_TX_EP_MASK	0x1f		/* EP0 + 4 Tx EPs */
67 #define DA8XX_USB_RX_EP_MASK	0x1e		/* 4 Rx EPs */
68 
69 /* USB interrupt register bits */
70 #define DA8XX_INTR_USB_SHIFT	16
71 #define DA8XX_INTR_USB_MASK	(0x1ff << DA8XX_INTR_USB_SHIFT) /* 8 Mentor */
72 					/* interrupts and DRVVBUS interrupt */
73 #define DA8XX_INTR_DRVVBUS	0x100
74 #define DA8XX_INTR_RX_SHIFT	8
75 #define DA8XX_INTR_RX_MASK	(DA8XX_USB_RX_EP_MASK << DA8XX_INTR_RX_SHIFT)
76 #define DA8XX_INTR_TX_SHIFT	0
77 #define DA8XX_INTR_TX_MASK	(DA8XX_USB_TX_EP_MASK << DA8XX_INTR_TX_SHIFT)
78 
79 #define DA8XX_MENTOR_CORE_OFFSET 0x400
80 
81 struct da8xx_glue {
82 	struct device		*dev;
83 	struct platform_device	*musb;
84 	struct platform_device	*usb_phy;
85 	struct clk		*clk;
86 	struct phy		*phy;
87 };
88 
89 /*
90  * Because we don't set CTRL.UINT, it's "important" to:
91  *	- not read/write INTRUSB/INTRUSBE (except during
92  *	  initial setup, as a workaround);
93  *	- use INTSET/INTCLR instead.
94  */
95 
96 /**
97  * da8xx_musb_enable - enable interrupts
98  */
99 static void da8xx_musb_enable(struct musb *musb)
100 {
101 	void __iomem *reg_base = musb->ctrl_base;
102 	u32 mask;
103 
104 	/* Workaround: setup IRQs through both register sets. */
105 	mask = ((musb->epmask & DA8XX_USB_TX_EP_MASK) << DA8XX_INTR_TX_SHIFT) |
106 	       ((musb->epmask & DA8XX_USB_RX_EP_MASK) << DA8XX_INTR_RX_SHIFT) |
107 	       DA8XX_INTR_USB_MASK;
108 	musb_writel(reg_base, DA8XX_USB_INTR_MASK_SET_REG, mask);
109 
110 	/* Force the DRVVBUS IRQ so we can start polling for ID change. */
111 	musb_writel(reg_base, DA8XX_USB_INTR_SRC_SET_REG,
112 			DA8XX_INTR_DRVVBUS << DA8XX_INTR_USB_SHIFT);
113 }
114 
115 /**
116  * da8xx_musb_disable - disable HDRC and flush interrupts
117  */
118 static void da8xx_musb_disable(struct musb *musb)
119 {
120 	void __iomem *reg_base = musb->ctrl_base;
121 
122 	musb_writel(reg_base, DA8XX_USB_INTR_MASK_CLEAR_REG,
123 		    DA8XX_INTR_USB_MASK |
124 		    DA8XX_INTR_TX_MASK | DA8XX_INTR_RX_MASK);
125 	musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
126 	musb_writel(reg_base, DA8XX_USB_END_OF_INTR_REG, 0);
127 }
128 
129 #define portstate(stmt)		stmt
130 
131 static void da8xx_musb_set_vbus(struct musb *musb, int is_on)
132 {
133 	WARN_ON(is_on && is_peripheral_active(musb));
134 }
135 
136 #define	POLL_SECONDS	2
137 
138 static struct timer_list otg_workaround;
139 
140 static void otg_timer(unsigned long _musb)
141 {
142 	struct musb		*musb = (void *)_musb;
143 	void __iomem		*mregs = musb->mregs;
144 	u8			devctl;
145 	unsigned long		flags;
146 
147 	/*
148 	 * We poll because DaVinci's won't expose several OTG-critical
149 	 * status change events (from the transceiver) otherwise.
150 	 */
151 	devctl = musb_readb(mregs, MUSB_DEVCTL);
152 	dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl,
153 		usb_otg_state_string(musb->xceiv->otg->state));
154 
155 	spin_lock_irqsave(&musb->lock, flags);
156 	switch (musb->xceiv->otg->state) {
157 	case OTG_STATE_A_WAIT_BCON:
158 		devctl &= ~MUSB_DEVCTL_SESSION;
159 		musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
160 
161 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
162 		if (devctl & MUSB_DEVCTL_BDEVICE) {
163 			musb->xceiv->otg->state = OTG_STATE_B_IDLE;
164 			MUSB_DEV_MODE(musb);
165 		} else {
166 			musb->xceiv->otg->state = OTG_STATE_A_IDLE;
167 			MUSB_HST_MODE(musb);
168 		}
169 		break;
170 	case OTG_STATE_A_WAIT_VFALL:
171 		/*
172 		 * Wait till VBUS falls below SessionEnd (~0.2 V); the 1.3
173 		 * RTL seems to mis-handle session "start" otherwise (or in
174 		 * our case "recover"), in routine "VBUS was valid by the time
175 		 * VBUSERR got reported during enumeration" cases.
176 		 */
177 		if (devctl & MUSB_DEVCTL_VBUS) {
178 			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
179 			break;
180 		}
181 		musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
182 		musb_writel(musb->ctrl_base, DA8XX_USB_INTR_SRC_SET_REG,
183 			    MUSB_INTR_VBUSERROR << DA8XX_INTR_USB_SHIFT);
184 		break;
185 	case OTG_STATE_B_IDLE:
186 		/*
187 		 * There's no ID-changed IRQ, so we have no good way to tell
188 		 * when to switch to the A-Default state machine (by setting
189 		 * the DEVCTL.Session bit).
190 		 *
191 		 * Workaround:  whenever we're in B_IDLE, try setting the
192 		 * session flag every few seconds.  If it works, ID was
193 		 * grounded and we're now in the A-Default state machine.
194 		 *
195 		 * NOTE: setting the session flag is _supposed_ to trigger
196 		 * SRP but clearly it doesn't.
197 		 */
198 		musb_writeb(mregs, MUSB_DEVCTL, devctl | MUSB_DEVCTL_SESSION);
199 		devctl = musb_readb(mregs, MUSB_DEVCTL);
200 		if (devctl & MUSB_DEVCTL_BDEVICE)
201 			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
202 		else
203 			musb->xceiv->otg->state = OTG_STATE_A_IDLE;
204 		break;
205 	default:
206 		break;
207 	}
208 	spin_unlock_irqrestore(&musb->lock, flags);
209 }
210 
211 static void da8xx_musb_try_idle(struct musb *musb, unsigned long timeout)
212 {
213 	static unsigned long last_timer;
214 
215 	if (timeout == 0)
216 		timeout = jiffies + msecs_to_jiffies(3);
217 
218 	/* Never idle if active, or when VBUS timeout is not set as host */
219 	if (musb->is_active || (musb->a_wait_bcon == 0 &&
220 				musb->xceiv->otg->state == OTG_STATE_A_WAIT_BCON)) {
221 		dev_dbg(musb->controller, "%s active, deleting timer\n",
222 			usb_otg_state_string(musb->xceiv->otg->state));
223 		del_timer(&otg_workaround);
224 		last_timer = jiffies;
225 		return;
226 	}
227 
228 	if (time_after(last_timer, timeout) && timer_pending(&otg_workaround)) {
229 		dev_dbg(musb->controller, "Longer idle timer already pending, ignoring...\n");
230 		return;
231 	}
232 	last_timer = timeout;
233 
234 	dev_dbg(musb->controller, "%s inactive, starting idle timer for %u ms\n",
235 		usb_otg_state_string(musb->xceiv->otg->state),
236 		jiffies_to_msecs(timeout - jiffies));
237 	mod_timer(&otg_workaround, timeout);
238 }
239 
240 static irqreturn_t da8xx_musb_interrupt(int irq, void *hci)
241 {
242 	struct musb		*musb = hci;
243 	void __iomem		*reg_base = musb->ctrl_base;
244 	struct usb_otg		*otg = musb->xceiv->otg;
245 	unsigned long		flags;
246 	irqreturn_t		ret = IRQ_NONE;
247 	u32			status;
248 
249 	spin_lock_irqsave(&musb->lock, flags);
250 
251 	/*
252 	 * NOTE: DA8XX shadows the Mentor IRQs.  Don't manage them through
253 	 * the Mentor registers (except for setup), use the TI ones and EOI.
254 	 */
255 
256 	/* Acknowledge and handle non-CPPI interrupts */
257 	status = musb_readl(reg_base, DA8XX_USB_INTR_SRC_MASKED_REG);
258 	if (!status)
259 		goto eoi;
260 
261 	musb_writel(reg_base, DA8XX_USB_INTR_SRC_CLEAR_REG, status);
262 	dev_dbg(musb->controller, "USB IRQ %08x\n", status);
263 
264 	musb->int_rx = (status & DA8XX_INTR_RX_MASK) >> DA8XX_INTR_RX_SHIFT;
265 	musb->int_tx = (status & DA8XX_INTR_TX_MASK) >> DA8XX_INTR_TX_SHIFT;
266 	musb->int_usb = (status & DA8XX_INTR_USB_MASK) >> DA8XX_INTR_USB_SHIFT;
267 
268 	/*
269 	 * DRVVBUS IRQs are the only proxy we have (a very poor one!) for
270 	 * DA8xx's missing ID change IRQ.  We need an ID change IRQ to
271 	 * switch appropriately between halves of the OTG state machine.
272 	 * Managing DEVCTL.Session per Mentor docs requires that we know its
273 	 * value but DEVCTL.BDevice is invalid without DEVCTL.Session set.
274 	 * Also, DRVVBUS pulses for SRP (but not at 5 V)...
275 	 */
276 	if (status & (DA8XX_INTR_DRVVBUS << DA8XX_INTR_USB_SHIFT)) {
277 		int drvvbus = musb_readl(reg_base, DA8XX_USB_STAT_REG);
278 		void __iomem *mregs = musb->mregs;
279 		u8 devctl = musb_readb(mregs, MUSB_DEVCTL);
280 		int err;
281 
282 		err = musb->int_usb & MUSB_INTR_VBUSERROR;
283 		if (err) {
284 			/*
285 			 * The Mentor core doesn't debounce VBUS as needed
286 			 * to cope with device connect current spikes. This
287 			 * means it's not uncommon for bus-powered devices
288 			 * to get VBUS errors during enumeration.
289 			 *
290 			 * This is a workaround, but newer RTL from Mentor
291 			 * seems to allow a better one: "re"-starting sessions
292 			 * without waiting for VBUS to stop registering in
293 			 * devctl.
294 			 */
295 			musb->int_usb &= ~MUSB_INTR_VBUSERROR;
296 			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VFALL;
297 			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
298 			WARNING("VBUS error workaround (delay coming)\n");
299 		} else if (drvvbus) {
300 			MUSB_HST_MODE(musb);
301 			otg->default_a = 1;
302 			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
303 			portstate(musb->port1_status |= USB_PORT_STAT_POWER);
304 			del_timer(&otg_workaround);
305 		} else {
306 			musb->is_active = 0;
307 			MUSB_DEV_MODE(musb);
308 			otg->default_a = 0;
309 			musb->xceiv->otg->state = OTG_STATE_B_IDLE;
310 			portstate(musb->port1_status &= ~USB_PORT_STAT_POWER);
311 		}
312 
313 		dev_dbg(musb->controller, "VBUS %s (%s)%s, devctl %02x\n",
314 				drvvbus ? "on" : "off",
315 				usb_otg_state_string(musb->xceiv->otg->state),
316 				err ? " ERROR" : "",
317 				devctl);
318 		ret = IRQ_HANDLED;
319 	}
320 
321 	if (musb->int_tx || musb->int_rx || musb->int_usb)
322 		ret |= musb_interrupt(musb);
323 
324  eoi:
325 	/* EOI needs to be written for the IRQ to be re-asserted. */
326 	if (ret == IRQ_HANDLED || status)
327 		musb_writel(reg_base, DA8XX_USB_END_OF_INTR_REG, 0);
328 
329 	/* Poll for ID change */
330 	if (musb->xceiv->otg->state == OTG_STATE_B_IDLE)
331 		mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
332 
333 	spin_unlock_irqrestore(&musb->lock, flags);
334 
335 	return ret;
336 }
337 
338 static int da8xx_musb_set_mode(struct musb *musb, u8 musb_mode)
339 {
340 	struct da8xx_glue *glue = dev_get_drvdata(musb->controller->parent);
341 	enum phy_mode phy_mode;
342 
343 	switch (musb_mode) {
344 	case MUSB_HOST:		/* Force VBUS valid, ID = 0 */
345 		phy_mode = PHY_MODE_USB_HOST;
346 		break;
347 	case MUSB_PERIPHERAL:	/* Force VBUS valid, ID = 1 */
348 		phy_mode = PHY_MODE_USB_DEVICE;
349 		break;
350 	case MUSB_OTG:		/* Don't override the VBUS/ID comparators */
351 		phy_mode = PHY_MODE_USB_OTG;
352 		break;
353 	default:
354 		return -EINVAL;
355 	}
356 
357 	return phy_set_mode(glue->phy, phy_mode);
358 }
359 
360 static int da8xx_musb_init(struct musb *musb)
361 {
362 	struct da8xx_glue *glue = dev_get_drvdata(musb->controller->parent);
363 	void __iomem *reg_base = musb->ctrl_base;
364 	u32 rev;
365 	int ret = -ENODEV;
366 
367 	musb->mregs += DA8XX_MENTOR_CORE_OFFSET;
368 
369 	/* Returns zero if e.g. not clocked */
370 	rev = musb_readl(reg_base, DA8XX_USB_REVISION_REG);
371 	if (!rev)
372 		goto fail;
373 
374 	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
375 	if (IS_ERR_OR_NULL(musb->xceiv)) {
376 		ret = -EPROBE_DEFER;
377 		goto fail;
378 	}
379 
380 	ret = clk_prepare_enable(glue->clk);
381 	if (ret) {
382 		dev_err(glue->dev, "failed to enable clock\n");
383 		goto fail;
384 	}
385 
386 	setup_timer(&otg_workaround, otg_timer, (unsigned long)musb);
387 
388 	/* Reset the controller */
389 	musb_writel(reg_base, DA8XX_USB_CTRL_REG, DA8XX_SOFT_RESET_MASK);
390 
391 	/* Start the on-chip PHY and its PLL. */
392 	ret = phy_init(glue->phy);
393 	if (ret) {
394 		dev_err(glue->dev, "Failed to init phy.\n");
395 		goto err_phy_init;
396 	}
397 
398 	ret = phy_power_on(glue->phy);
399 	if (ret) {
400 		dev_err(glue->dev, "Failed to power on phy.\n");
401 		goto err_phy_power_on;
402 	}
403 
404 	msleep(5);
405 
406 	/* NOTE: IRQs are in mixed mode, not bypass to pure MUSB */
407 	pr_debug("DA8xx OTG revision %08x, control %02x\n", rev,
408 		 musb_readb(reg_base, DA8XX_USB_CTRL_REG));
409 
410 	musb->isr = da8xx_musb_interrupt;
411 	return 0;
412 
413 err_phy_power_on:
414 	phy_exit(glue->phy);
415 err_phy_init:
416 	clk_disable_unprepare(glue->clk);
417 fail:
418 	return ret;
419 }
420 
421 static int da8xx_musb_exit(struct musb *musb)
422 {
423 	struct da8xx_glue *glue = dev_get_drvdata(musb->controller->parent);
424 
425 	del_timer_sync(&otg_workaround);
426 
427 	phy_power_off(glue->phy);
428 	phy_exit(glue->phy);
429 	clk_disable_unprepare(glue->clk);
430 
431 	usb_put_phy(musb->xceiv);
432 
433 	return 0;
434 }
435 
436 static const struct musb_platform_ops da8xx_ops = {
437 	.quirks		= MUSB_DMA_CPPI | MUSB_INDEXED_EP,
438 	.init		= da8xx_musb_init,
439 	.exit		= da8xx_musb_exit,
440 
441 	.fifo_mode	= 2,
442 #ifdef CONFIG_USB_TI_CPPI_DMA
443 	.dma_init	= cppi_dma_controller_create,
444 	.dma_exit	= cppi_dma_controller_destroy,
445 #endif
446 	.enable		= da8xx_musb_enable,
447 	.disable	= da8xx_musb_disable,
448 
449 	.set_mode	= da8xx_musb_set_mode,
450 	.try_idle	= da8xx_musb_try_idle,
451 
452 	.set_vbus	= da8xx_musb_set_vbus,
453 };
454 
455 static const struct platform_device_info da8xx_dev_info = {
456 	.name		= "musb-hdrc",
457 	.id		= PLATFORM_DEVID_AUTO,
458 	.dma_mask	= DMA_BIT_MASK(32),
459 };
460 
461 static int da8xx_probe(struct platform_device *pdev)
462 {
463 	struct resource musb_resources[2];
464 	struct musb_hdrc_platform_data	*pdata = dev_get_platdata(&pdev->dev);
465 	struct da8xx_glue		*glue;
466 	struct platform_device_info	pinfo;
467 	struct clk			*clk;
468 	int				ret;
469 
470 	glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
471 	if (!glue)
472 		return -ENOMEM;
473 
474 	clk = devm_clk_get(&pdev->dev, "usb20");
475 	if (IS_ERR(clk)) {
476 		dev_err(&pdev->dev, "failed to get clock\n");
477 		return PTR_ERR(clk);
478 	}
479 
480 	glue->phy = devm_phy_get(&pdev->dev, "usb-phy");
481 	if (IS_ERR(glue->phy)) {
482 		dev_err(&pdev->dev, "failed to get phy\n");
483 		return PTR_ERR(glue->phy);
484 	}
485 
486 	glue->dev			= &pdev->dev;
487 	glue->clk			= clk;
488 
489 	pdata->platform_ops		= &da8xx_ops;
490 
491 	glue->usb_phy = usb_phy_generic_register();
492 	ret = PTR_ERR_OR_ZERO(glue->usb_phy);
493 	if (ret) {
494 		dev_err(&pdev->dev, "failed to register usb_phy\n");
495 		return ret;
496 	}
497 	platform_set_drvdata(pdev, glue);
498 
499 	memset(musb_resources, 0x00, sizeof(*musb_resources) *
500 			ARRAY_SIZE(musb_resources));
501 
502 	musb_resources[0].name = pdev->resource[0].name;
503 	musb_resources[0].start = pdev->resource[0].start;
504 	musb_resources[0].end = pdev->resource[0].end;
505 	musb_resources[0].flags = pdev->resource[0].flags;
506 
507 	musb_resources[1].name = pdev->resource[1].name;
508 	musb_resources[1].start = pdev->resource[1].start;
509 	musb_resources[1].end = pdev->resource[1].end;
510 	musb_resources[1].flags = pdev->resource[1].flags;
511 
512 	pinfo = da8xx_dev_info;
513 	pinfo.parent = &pdev->dev;
514 	pinfo.res = musb_resources;
515 	pinfo.num_res = ARRAY_SIZE(musb_resources);
516 	pinfo.data = pdata;
517 	pinfo.size_data = sizeof(*pdata);
518 
519 	glue->musb = platform_device_register_full(&pinfo);
520 	ret = PTR_ERR_OR_ZERO(glue->musb);
521 	if (ret) {
522 		dev_err(&pdev->dev, "failed to register musb device: %d\n", ret);
523 		usb_phy_generic_unregister(glue->usb_phy);
524 	}
525 
526 	return ret;
527 }
528 
529 static int da8xx_remove(struct platform_device *pdev)
530 {
531 	struct da8xx_glue		*glue = platform_get_drvdata(pdev);
532 
533 	platform_device_unregister(glue->musb);
534 	usb_phy_generic_unregister(glue->usb_phy);
535 
536 	return 0;
537 }
538 
539 static struct platform_driver da8xx_driver = {
540 	.probe		= da8xx_probe,
541 	.remove		= da8xx_remove,
542 	.driver		= {
543 		.name	= "musb-da8xx",
544 	},
545 };
546 
547 MODULE_DESCRIPTION("DA8xx/OMAP-L1x MUSB Glue Layer");
548 MODULE_AUTHOR("Sergei Shtylyov <sshtylyov@ru.mvista.com>");
549 MODULE_LICENSE("GPL v2");
550 module_platform_driver(da8xx_driver);
551