xref: /openbmc/linux/drivers/usb/musb/da8xx.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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/init.h>
30 #include <linux/clk.h>
31 #include <linux/io.h>
32 
33 #include <mach/da8xx.h>
34 #include <mach/usb.h>
35 
36 #include "musb_core.h"
37 
38 /*
39  * DA8XX specific definitions
40  */
41 
42 /* USB 2.0 OTG module registers */
43 #define DA8XX_USB_REVISION_REG	0x00
44 #define DA8XX_USB_CTRL_REG	0x04
45 #define DA8XX_USB_STAT_REG	0x08
46 #define DA8XX_USB_EMULATION_REG 0x0c
47 #define DA8XX_USB_MODE_REG	0x10	/* Transparent, CDC, [Generic] RNDIS */
48 #define DA8XX_USB_AUTOREQ_REG	0x14
49 #define DA8XX_USB_SRP_FIX_TIME_REG 0x18
50 #define DA8XX_USB_TEARDOWN_REG	0x1c
51 #define DA8XX_USB_INTR_SRC_REG	0x20
52 #define DA8XX_USB_INTR_SRC_SET_REG 0x24
53 #define DA8XX_USB_INTR_SRC_CLEAR_REG 0x28
54 #define DA8XX_USB_INTR_MASK_REG 0x2c
55 #define DA8XX_USB_INTR_MASK_SET_REG 0x30
56 #define DA8XX_USB_INTR_MASK_CLEAR_REG 0x34
57 #define DA8XX_USB_INTR_SRC_MASKED_REG 0x38
58 #define DA8XX_USB_END_OF_INTR_REG 0x3c
59 #define DA8XX_USB_GENERIC_RNDIS_EP_SIZE_REG(n) (0x50 + (((n) - 1) << 2))
60 
61 /* Control register bits */
62 #define DA8XX_SOFT_RESET_MASK	1
63 
64 #define DA8XX_USB_TX_EP_MASK	0x1f		/* EP0 + 4 Tx EPs */
65 #define DA8XX_USB_RX_EP_MASK	0x1e		/* 4 Rx EPs */
66 
67 /* USB interrupt register bits */
68 #define DA8XX_INTR_USB_SHIFT	16
69 #define DA8XX_INTR_USB_MASK	(0x1ff << DA8XX_INTR_USB_SHIFT) /* 8 Mentor */
70 					/* interrupts and DRVVBUS interrupt */
71 #define DA8XX_INTR_DRVVBUS	0x100
72 #define DA8XX_INTR_RX_SHIFT	8
73 #define DA8XX_INTR_RX_MASK	(DA8XX_USB_RX_EP_MASK << DA8XX_INTR_RX_SHIFT)
74 #define DA8XX_INTR_TX_SHIFT	0
75 #define DA8XX_INTR_TX_MASK	(DA8XX_USB_TX_EP_MASK << DA8XX_INTR_TX_SHIFT)
76 
77 #define DA8XX_MENTOR_CORE_OFFSET 0x400
78 
79 #define CFGCHIP2	IO_ADDRESS(DA8XX_SYSCFG0_BASE + DA8XX_CFGCHIP2_REG)
80 
81 /*
82  * REVISIT (PM): we should be able to keep the PHY in low power mode most
83  * of the time (24 MHz oscillator and PLL off, etc.) by setting POWER.D0
84  * and, when in host mode, autosuspending idle root ports... PHY_PLLON
85  * (overriding SUSPENDM?) then likely needs to stay off.
86  */
87 
88 static inline void phy_on(void)
89 {
90 	u32 cfgchip2 = __raw_readl(CFGCHIP2);
91 
92 	/*
93 	 * Start the on-chip PHY and its PLL.
94 	 */
95 	cfgchip2 &= ~(CFGCHIP2_RESET | CFGCHIP2_PHYPWRDN | CFGCHIP2_OTGPWRDN);
96 	cfgchip2 |= CFGCHIP2_PHY_PLLON;
97 	__raw_writel(cfgchip2, CFGCHIP2);
98 
99 	pr_info("Waiting for USB PHY clock good...\n");
100 	while (!(__raw_readl(CFGCHIP2) & CFGCHIP2_PHYCLKGD))
101 		cpu_relax();
102 }
103 
104 static inline void phy_off(void)
105 {
106 	u32 cfgchip2 = __raw_readl(CFGCHIP2);
107 
108 	/*
109 	 * Ensure that USB 1.1 reference clock is not being sourced from
110 	 * USB 2.0 PHY.  Otherwise do not power down the PHY.
111 	 */
112 	if (!(cfgchip2 & CFGCHIP2_USB1PHYCLKMUX) &&
113 	     (cfgchip2 & CFGCHIP2_USB1SUSPENDM)) {
114 		pr_warning("USB 1.1 clocked from USB 2.0 PHY -- "
115 			   "can't power it down\n");
116 		return;
117 	}
118 
119 	/*
120 	 * Power down the on-chip PHY.
121 	 */
122 	cfgchip2 |= CFGCHIP2_PHYPWRDN | CFGCHIP2_OTGPWRDN;
123 	__raw_writel(cfgchip2, CFGCHIP2);
124 }
125 
126 /*
127  * Because we don't set CTRL.UINT, it's "important" to:
128  *	- not read/write INTRUSB/INTRUSBE (except during
129  *	  initial setup, as a workaround);
130  *	- use INTSET/INTCLR instead.
131  */
132 
133 /**
134  * musb_platform_enable - enable interrupts
135  */
136 void musb_platform_enable(struct musb *musb)
137 {
138 	void __iomem *reg_base = musb->ctrl_base;
139 	u32 mask;
140 
141 	/* Workaround: setup IRQs through both register sets. */
142 	mask = ((musb->epmask & DA8XX_USB_TX_EP_MASK) << DA8XX_INTR_TX_SHIFT) |
143 	       ((musb->epmask & DA8XX_USB_RX_EP_MASK) << DA8XX_INTR_RX_SHIFT) |
144 	       DA8XX_INTR_USB_MASK;
145 	musb_writel(reg_base, DA8XX_USB_INTR_MASK_SET_REG, mask);
146 
147 	/* Force the DRVVBUS IRQ so we can start polling for ID change. */
148 	if (is_otg_enabled(musb))
149 		musb_writel(reg_base, DA8XX_USB_INTR_SRC_SET_REG,
150 			    DA8XX_INTR_DRVVBUS << DA8XX_INTR_USB_SHIFT);
151 }
152 
153 /**
154  * musb_platform_disable - disable HDRC and flush interrupts
155  */
156 void musb_platform_disable(struct musb *musb)
157 {
158 	void __iomem *reg_base = musb->ctrl_base;
159 
160 	musb_writel(reg_base, DA8XX_USB_INTR_MASK_CLEAR_REG,
161 		    DA8XX_INTR_USB_MASK |
162 		    DA8XX_INTR_TX_MASK | DA8XX_INTR_RX_MASK);
163 	musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
164 	musb_writel(reg_base, DA8XX_USB_END_OF_INTR_REG, 0);
165 }
166 
167 #ifdef CONFIG_USB_MUSB_HDRC_HCD
168 #define portstate(stmt) 	stmt
169 #else
170 #define portstate(stmt)
171 #endif
172 
173 static void da8xx_set_vbus(struct musb *musb, int is_on)
174 {
175 	WARN_ON(is_on && is_peripheral_active(musb));
176 }
177 
178 #define	POLL_SECONDS	2
179 
180 static struct timer_list otg_workaround;
181 
182 static void otg_timer(unsigned long _musb)
183 {
184 	struct musb		*musb = (void *)_musb;
185 	void __iomem		*mregs = musb->mregs;
186 	u8			devctl;
187 	unsigned long		flags;
188 
189 	/*
190 	 * We poll because DaVinci's won't expose several OTG-critical
191 	 * status change events (from the transceiver) otherwise.
192 	 */
193 	devctl = musb_readb(mregs, MUSB_DEVCTL);
194 	DBG(7, "Poll devctl %02x (%s)\n", devctl, otg_state_string(musb));
195 
196 	spin_lock_irqsave(&musb->lock, flags);
197 	switch (musb->xceiv->state) {
198 	case OTG_STATE_A_WAIT_BCON:
199 		devctl &= ~MUSB_DEVCTL_SESSION;
200 		musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
201 
202 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
203 		if (devctl & MUSB_DEVCTL_BDEVICE) {
204 			musb->xceiv->state = OTG_STATE_B_IDLE;
205 			MUSB_DEV_MODE(musb);
206 		} else {
207 			musb->xceiv->state = OTG_STATE_A_IDLE;
208 			MUSB_HST_MODE(musb);
209 		}
210 		break;
211 	case OTG_STATE_A_WAIT_VFALL:
212 		/*
213 		 * Wait till VBUS falls below SessionEnd (~0.2 V); the 1.3
214 		 * RTL seems to mis-handle session "start" otherwise (or in
215 		 * our case "recover"), in routine "VBUS was valid by the time
216 		 * VBUSERR got reported during enumeration" cases.
217 		 */
218 		if (devctl & MUSB_DEVCTL_VBUS) {
219 			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
220 			break;
221 		}
222 		musb->xceiv->state = OTG_STATE_A_WAIT_VRISE;
223 		musb_writel(musb->ctrl_base, DA8XX_USB_INTR_SRC_SET_REG,
224 			    MUSB_INTR_VBUSERROR << DA8XX_INTR_USB_SHIFT);
225 		break;
226 	case OTG_STATE_B_IDLE:
227 		if (!is_peripheral_enabled(musb))
228 			break;
229 
230 		/*
231 		 * There's no ID-changed IRQ, so we have no good way to tell
232 		 * when to switch to the A-Default state machine (by setting
233 		 * the DEVCTL.Session bit).
234 		 *
235 		 * Workaround:  whenever we're in B_IDLE, try setting the
236 		 * session flag every few seconds.  If it works, ID was
237 		 * grounded and we're now in the A-Default state machine.
238 		 *
239 		 * NOTE: setting the session flag is _supposed_ to trigger
240 		 * SRP but clearly it doesn't.
241 		 */
242 		musb_writeb(mregs, MUSB_DEVCTL, devctl | MUSB_DEVCTL_SESSION);
243 		devctl = musb_readb(mregs, MUSB_DEVCTL);
244 		if (devctl & MUSB_DEVCTL_BDEVICE)
245 			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
246 		else
247 			musb->xceiv->state = OTG_STATE_A_IDLE;
248 		break;
249 	default:
250 		break;
251 	}
252 	spin_unlock_irqrestore(&musb->lock, flags);
253 }
254 
255 void musb_platform_try_idle(struct musb *musb, unsigned long timeout)
256 {
257 	static unsigned long last_timer;
258 
259 	if (!is_otg_enabled(musb))
260 		return;
261 
262 	if (timeout == 0)
263 		timeout = jiffies + msecs_to_jiffies(3);
264 
265 	/* Never idle if active, or when VBUS timeout is not set as host */
266 	if (musb->is_active || (musb->a_wait_bcon == 0 &&
267 				musb->xceiv->state == OTG_STATE_A_WAIT_BCON)) {
268 		DBG(4, "%s active, deleting timer\n", otg_state_string(musb));
269 		del_timer(&otg_workaround);
270 		last_timer = jiffies;
271 		return;
272 	}
273 
274 	if (time_after(last_timer, timeout) && timer_pending(&otg_workaround)) {
275 		DBG(4, "Longer idle timer already pending, ignoring...\n");
276 		return;
277 	}
278 	last_timer = timeout;
279 
280 	DBG(4, "%s inactive, starting idle timer for %u ms\n",
281 	    otg_state_string(musb), jiffies_to_msecs(timeout - jiffies));
282 	mod_timer(&otg_workaround, timeout);
283 }
284 
285 static irqreturn_t da8xx_interrupt(int irq, void *hci)
286 {
287 	struct musb		*musb = hci;
288 	void __iomem		*reg_base = musb->ctrl_base;
289 	unsigned long		flags;
290 	irqreturn_t		ret = IRQ_NONE;
291 	u32			status;
292 
293 	spin_lock_irqsave(&musb->lock, flags);
294 
295 	/*
296 	 * NOTE: DA8XX shadows the Mentor IRQs.  Don't manage them through
297 	 * the Mentor registers (except for setup), use the TI ones and EOI.
298 	 */
299 
300 	/* Acknowledge and handle non-CPPI interrupts */
301 	status = musb_readl(reg_base, DA8XX_USB_INTR_SRC_MASKED_REG);
302 	if (!status)
303 		goto eoi;
304 
305 	musb_writel(reg_base, DA8XX_USB_INTR_SRC_CLEAR_REG, status);
306 	DBG(4, "USB IRQ %08x\n", status);
307 
308 	musb->int_rx = (status & DA8XX_INTR_RX_MASK) >> DA8XX_INTR_RX_SHIFT;
309 	musb->int_tx = (status & DA8XX_INTR_TX_MASK) >> DA8XX_INTR_TX_SHIFT;
310 	musb->int_usb = (status & DA8XX_INTR_USB_MASK) >> DA8XX_INTR_USB_SHIFT;
311 
312 	/*
313 	 * DRVVBUS IRQs are the only proxy we have (a very poor one!) for
314 	 * DA8xx's missing ID change IRQ.  We need an ID change IRQ to
315 	 * switch appropriately between halves of the OTG state machine.
316 	 * Managing DEVCTL.Session per Mentor docs requires that we know its
317 	 * value but DEVCTL.BDevice is invalid without DEVCTL.Session set.
318 	 * Also, DRVVBUS pulses for SRP (but not at 5 V)...
319 	 */
320 	if (status & (DA8XX_INTR_DRVVBUS << DA8XX_INTR_USB_SHIFT)) {
321 		int drvvbus = musb_readl(reg_base, DA8XX_USB_STAT_REG);
322 		void __iomem *mregs = musb->mregs;
323 		u8 devctl = musb_readb(mregs, MUSB_DEVCTL);
324 		int err;
325 
326 		err = is_host_enabled(musb) && (musb->int_usb &
327 						MUSB_INTR_VBUSERROR);
328 		if (err) {
329 			/*
330 			 * The Mentor core doesn't debounce VBUS as needed
331 			 * to cope with device connect current spikes. This
332 			 * means it's not uncommon for bus-powered devices
333 			 * to get VBUS errors during enumeration.
334 			 *
335 			 * This is a workaround, but newer RTL from Mentor
336 			 * seems to allow a better one: "re"-starting sessions
337 			 * without waiting for VBUS to stop registering in
338 			 * devctl.
339 			 */
340 			musb->int_usb &= ~MUSB_INTR_VBUSERROR;
341 			musb->xceiv->state = OTG_STATE_A_WAIT_VFALL;
342 			mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
343 			WARNING("VBUS error workaround (delay coming)\n");
344 		} else if (is_host_enabled(musb) && drvvbus) {
345 			MUSB_HST_MODE(musb);
346 			musb->xceiv->default_a = 1;
347 			musb->xceiv->state = OTG_STATE_A_WAIT_VRISE;
348 			portstate(musb->port1_status |= USB_PORT_STAT_POWER);
349 			del_timer(&otg_workaround);
350 		} else {
351 			musb->is_active = 0;
352 			MUSB_DEV_MODE(musb);
353 			musb->xceiv->default_a = 0;
354 			musb->xceiv->state = OTG_STATE_B_IDLE;
355 			portstate(musb->port1_status &= ~USB_PORT_STAT_POWER);
356 		}
357 
358 		DBG(2, "VBUS %s (%s)%s, devctl %02x\n",
359 				drvvbus ? "on" : "off",
360 				otg_state_string(musb),
361 				err ? " ERROR" : "",
362 				devctl);
363 		ret = IRQ_HANDLED;
364 	}
365 
366 	if (musb->int_tx || musb->int_rx || musb->int_usb)
367 		ret |= musb_interrupt(musb);
368 
369  eoi:
370 	/* EOI needs to be written for the IRQ to be re-asserted. */
371 	if (ret == IRQ_HANDLED || status)
372 		musb_writel(reg_base, DA8XX_USB_END_OF_INTR_REG, 0);
373 
374 	/* Poll for ID change */
375 	if (is_otg_enabled(musb) && musb->xceiv->state == OTG_STATE_B_IDLE)
376 		mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
377 
378 	spin_unlock_irqrestore(&musb->lock, flags);
379 
380 	return ret;
381 }
382 
383 int musb_platform_set_mode(struct musb *musb, u8 musb_mode)
384 {
385 	u32 cfgchip2 = __raw_readl(CFGCHIP2);
386 
387 	cfgchip2 &= ~CFGCHIP2_OTGMODE;
388 	switch (musb_mode) {
389 #ifdef	CONFIG_USB_MUSB_HDRC_HCD
390 	case MUSB_HOST:		/* Force VBUS valid, ID = 0 */
391 		cfgchip2 |= CFGCHIP2_FORCE_HOST;
392 		break;
393 #endif
394 #ifdef	CONFIG_USB_GADGET_MUSB_HDRC
395 	case MUSB_PERIPHERAL:	/* Force VBUS valid, ID = 1 */
396 		cfgchip2 |= CFGCHIP2_FORCE_DEVICE;
397 		break;
398 #endif
399 #ifdef	CONFIG_USB_MUSB_OTG
400 	case MUSB_OTG:		/* Don't override the VBUS/ID comparators */
401 		cfgchip2 |= CFGCHIP2_NO_OVERRIDE;
402 		break;
403 #endif
404 	default:
405 		DBG(2, "Trying to set unsupported mode %u\n", musb_mode);
406 	}
407 
408 	__raw_writel(cfgchip2, CFGCHIP2);
409 	return 0;
410 }
411 
412 int __init musb_platform_init(struct musb *musb, void *board_data)
413 {
414 	void __iomem *reg_base = musb->ctrl_base;
415 	u32 rev;
416 
417 	musb->mregs += DA8XX_MENTOR_CORE_OFFSET;
418 
419 	clk_enable(musb->clock);
420 
421 	/* Returns zero if e.g. not clocked */
422 	rev = musb_readl(reg_base, DA8XX_USB_REVISION_REG);
423 	if (!rev)
424 		goto fail;
425 
426 	usb_nop_xceiv_register();
427 	musb->xceiv = otg_get_transceiver();
428 	if (!musb->xceiv)
429 		goto fail;
430 
431 	if (is_host_enabled(musb))
432 		setup_timer(&otg_workaround, otg_timer, (unsigned long)musb);
433 
434 	musb->board_set_vbus = da8xx_set_vbus;
435 
436 	/* Reset the controller */
437 	musb_writel(reg_base, DA8XX_USB_CTRL_REG, DA8XX_SOFT_RESET_MASK);
438 
439 	/* Start the on-chip PHY and its PLL. */
440 	phy_on();
441 
442 	msleep(5);
443 
444 	/* NOTE: IRQs are in mixed mode, not bypass to pure MUSB */
445 	pr_debug("DA8xx OTG revision %08x, PHY %03x, control %02x\n",
446 		 rev, __raw_readl(CFGCHIP2),
447 		 musb_readb(reg_base, DA8XX_USB_CTRL_REG));
448 
449 	musb->isr = da8xx_interrupt;
450 	return 0;
451 fail:
452 	clk_disable(musb->clock);
453 	return -ENODEV;
454 }
455 
456 int musb_platform_exit(struct musb *musb)
457 {
458 	if (is_host_enabled(musb))
459 		del_timer_sync(&otg_workaround);
460 
461 	phy_off();
462 
463 	otg_put_transceiver(musb->xceiv);
464 	usb_nop_xceiv_unregister();
465 
466 	clk_disable(musb->clock);
467 
468 	return 0;
469 }
470