1 /* Low-level parallel port routines for built-in port on SGI IP32
2  *
3  * Author: Arnaud Giersch <arnaud.giersch@free.fr>
4  *
5  * Based on parport_pc.c by
6  *	Phil Blundell, Tim Waugh, Jose Renau, David Campbell,
7  *	Andrea Arcangeli, et al.
8  *
9  * Thanks to Ilya A. Volynets-Evenbakh for his help.
10  *
11  * Copyright (C) 2005, 2006 Arnaud Giersch.
12  *
13  * This program is free software; you can redistribute it and/or modify it
14  * under the terms of the GNU General Public License as published by the Free
15  * Software Foundation; either version 2 of the License, or (at your option)
16  * any later version.
17  *
18  * This program is distributed in the hope that it will be useful, but WITHOUT
19  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
20  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
21  * more details.
22  *
23  * You should have received a copy of the GNU General Public License along
24  * with this program; if not, write to the Free Software Foundation, Inc., 59
25  * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
26  */
27 
28 /* Current status:
29  *
30  *	Basic SPP and PS2 modes are supported.
31  *	Support for parallel port IRQ is present.
32  *	Hardware SPP (a.k.a. compatibility), EPP, and ECP modes are
33  *	supported.
34  *	SPP/ECP FIFO can be driven in PIO or DMA mode.  PIO mode can work with
35  *	or without interrupt support.
36  *
37  *	Hardware ECP mode is not fully implemented (ecp_read_data and
38  *	ecp_write_addr are actually missing).
39  *
40  * To do:
41  *
42  *	Fully implement ECP mode.
43  *	EPP and ECP mode need to be tested.  I currently do not own any
44  *	peripheral supporting these extended mode, and cannot test them.
45  *	If DMA mode works well, decide if support for PIO FIFO modes should be
46  *	dropped.
47  *	Use the io{read,write} family functions when they become available in
48  *	the linux-mips.org tree.  Note: the MIPS specific functions readsb()
49  *	and writesb() are to be translated by ioread8_rep() and iowrite8_rep()
50  *	respectively.
51  */
52 
53 /* The built-in parallel port on the SGI 02 workstation (a.k.a. IP32) is an
54  * IEEE 1284 parallel port driven by a Texas Instrument TL16PIR552PH chip[1].
55  * This chip supports SPP, bidirectional, EPP and ECP modes.  It has a 16 byte
56  * FIFO buffer and supports DMA transfers.
57  *
58  * [1] http://focus.ti.com/docs/prod/folders/print/tl16pir552.html
59  *
60  * Theoretically, we could simply use the parport_pc module.  It is however
61  * not so simple.  The parport_pc code assumes that the parallel port
62  * registers are port-mapped.  On the O2, they are memory-mapped.
63  * Furthermore, each register is replicated on 256 consecutive addresses (as
64  * it is for the built-in serial ports on the same chip).
65  */
66 
67 /*--- Some configuration defines ---------------------------------------*/
68 
69 /* DEBUG_PARPORT_IP32
70  *	0	disable debug
71  *	1	standard level: pr_debug1 is enabled
72  *	2	parport_ip32_dump_state is enabled
73  *	>=3	verbose level: pr_debug is enabled
74  */
75 #if !defined(DEBUG_PARPORT_IP32)
76 #	define DEBUG_PARPORT_IP32  0	/* 0 (disabled) for production */
77 #endif
78 
79 /*----------------------------------------------------------------------*/
80 
81 /* Setup DEBUG macros.  This is done before any includes, just in case we
82  * activate pr_debug() with DEBUG_PARPORT_IP32 >= 3.
83  */
84 #if DEBUG_PARPORT_IP32 == 1
85 #	warning DEBUG_PARPORT_IP32 == 1
86 #elif DEBUG_PARPORT_IP32 == 2
87 #	warning DEBUG_PARPORT_IP32 == 2
88 #elif DEBUG_PARPORT_IP32 >= 3
89 #	warning DEBUG_PARPORT_IP32 >= 3
90 #	if !defined(DEBUG)
91 #		define DEBUG /* enable pr_debug() in kernel.h */
92 #	endif
93 #endif
94 
95 #include <linux/completion.h>
96 #include <linux/delay.h>
97 #include <linux/dma-mapping.h>
98 #include <linux/err.h>
99 #include <linux/init.h>
100 #include <linux/interrupt.h>
101 #include <linux/jiffies.h>
102 #include <linux/kernel.h>
103 #include <linux/module.h>
104 #include <linux/parport.h>
105 #include <linux/sched.h>
106 #include <linux/spinlock.h>
107 #include <linux/stddef.h>
108 #include <linux/types.h>
109 #include <asm/io.h>
110 #include <asm/ip32/ip32_ints.h>
111 #include <asm/ip32/mace.h>
112 
113 /*--- Global variables -------------------------------------------------*/
114 
115 /* Verbose probing on by default for debugging. */
116 #if DEBUG_PARPORT_IP32 >= 1
117 #	define DEFAULT_VERBOSE_PROBING	1
118 #else
119 #	define DEFAULT_VERBOSE_PROBING	0
120 #endif
121 
122 /* Default prefix for printk */
123 #define PPIP32 "parport_ip32: "
124 
125 /*
126  * These are the module parameters:
127  * @features:		bit mask of features to enable/disable
128  *			(all enabled by default)
129  * @verbose_probing:	log chit-chat during initialization
130  */
131 #define PARPORT_IP32_ENABLE_IRQ	(1U << 0)
132 #define PARPORT_IP32_ENABLE_DMA	(1U << 1)
133 #define PARPORT_IP32_ENABLE_SPP	(1U << 2)
134 #define PARPORT_IP32_ENABLE_EPP	(1U << 3)
135 #define PARPORT_IP32_ENABLE_ECP	(1U << 4)
136 static unsigned int features =	~0U;
137 static int verbose_probing =	DEFAULT_VERBOSE_PROBING;
138 
139 /* We do not support more than one port. */
140 static struct parport *this_port = NULL;
141 
142 /* Timing constants for FIFO modes.  */
143 #define FIFO_NFAULT_TIMEOUT	100	/* milliseconds */
144 #define FIFO_POLLING_INTERVAL	50	/* microseconds */
145 
146 /*--- I/O register definitions -----------------------------------------*/
147 
148 /**
149  * struct parport_ip32_regs - virtual addresses of parallel port registers
150  * @data:	Data Register
151  * @dsr:	Device Status Register
152  * @dcr:	Device Control Register
153  * @eppAddr:	EPP Address Register
154  * @eppData0:	EPP Data Register 0
155  * @eppData1:	EPP Data Register 1
156  * @eppData2:	EPP Data Register 2
157  * @eppData3:	EPP Data Register 3
158  * @ecpAFifo:	ECP Address FIFO
159  * @fifo:	General FIFO register.  The same address is used for:
160  *		- cFifo, the Parallel Port DATA FIFO
161  *		- ecpDFifo, the ECP Data FIFO
162  *		- tFifo, the ECP Test FIFO
163  * @cnfgA:	Configuration Register A
164  * @cnfgB:	Configuration Register B
165  * @ecr:	Extended Control Register
166  */
167 struct parport_ip32_regs {
168 	void __iomem *data;
169 	void __iomem *dsr;
170 	void __iomem *dcr;
171 	void __iomem *eppAddr;
172 	void __iomem *eppData0;
173 	void __iomem *eppData1;
174 	void __iomem *eppData2;
175 	void __iomem *eppData3;
176 	void __iomem *ecpAFifo;
177 	void __iomem *fifo;
178 	void __iomem *cnfgA;
179 	void __iomem *cnfgB;
180 	void __iomem *ecr;
181 };
182 
183 /* Device Status Register */
184 #define DSR_nBUSY		(1U << 7)	/* PARPORT_STATUS_BUSY */
185 #define DSR_nACK		(1U << 6)	/* PARPORT_STATUS_ACK */
186 #define DSR_PERROR		(1U << 5)	/* PARPORT_STATUS_PAPEROUT */
187 #define DSR_SELECT		(1U << 4)	/* PARPORT_STATUS_SELECT */
188 #define DSR_nFAULT		(1U << 3)	/* PARPORT_STATUS_ERROR */
189 #define DSR_nPRINT		(1U << 2)	/* specific to TL16PIR552 */
190 /* #define DSR_reserved		(1U << 1) */
191 #define DSR_TIMEOUT		(1U << 0)	/* EPP timeout */
192 
193 /* Device Control Register */
194 /* #define DCR_reserved		(1U << 7) | (1U <<  6) */
195 #define DCR_DIR			(1U << 5)	/* direction */
196 #define DCR_IRQ			(1U << 4)	/* interrupt on nAck */
197 #define DCR_SELECT		(1U << 3)	/* PARPORT_CONTROL_SELECT */
198 #define DCR_nINIT		(1U << 2)	/* PARPORT_CONTROL_INIT */
199 #define DCR_AUTOFD		(1U << 1)	/* PARPORT_CONTROL_AUTOFD */
200 #define DCR_STROBE		(1U << 0)	/* PARPORT_CONTROL_STROBE */
201 
202 /* ECP Configuration Register A */
203 #define CNFGA_IRQ		(1U << 7)
204 #define CNFGA_ID_MASK		((1U << 6) | (1U << 5) | (1U << 4))
205 #define CNFGA_ID_SHIFT		4
206 #define CNFGA_ID_16		(00U << CNFGA_ID_SHIFT)
207 #define CNFGA_ID_8		(01U << CNFGA_ID_SHIFT)
208 #define CNFGA_ID_32		(02U << CNFGA_ID_SHIFT)
209 /* #define CNFGA_reserved	(1U << 3) */
210 #define CNFGA_nBYTEINTRANS	(1U << 2)
211 #define CNFGA_PWORDLEFT		((1U << 1) | (1U << 0))
212 
213 /* ECP Configuration Register B */
214 #define CNFGB_COMPRESS		(1U << 7)
215 #define CNFGB_INTRVAL		(1U << 6)
216 #define CNFGB_IRQ_MASK		((1U << 5) | (1U << 4) | (1U << 3))
217 #define CNFGB_IRQ_SHIFT		3
218 #define CNFGB_DMA_MASK		((1U << 2) | (1U << 1) | (1U << 0))
219 #define CNFGB_DMA_SHIFT		0
220 
221 /* Extended Control Register */
222 #define ECR_MODE_MASK		((1U << 7) | (1U << 6) | (1U << 5))
223 #define ECR_MODE_SHIFT		5
224 #define ECR_MODE_SPP		(00U << ECR_MODE_SHIFT)
225 #define ECR_MODE_PS2		(01U << ECR_MODE_SHIFT)
226 #define ECR_MODE_PPF		(02U << ECR_MODE_SHIFT)
227 #define ECR_MODE_ECP		(03U << ECR_MODE_SHIFT)
228 #define ECR_MODE_EPP		(04U << ECR_MODE_SHIFT)
229 /* #define ECR_MODE_reserved	(05U << ECR_MODE_SHIFT) */
230 #define ECR_MODE_TST		(06U << ECR_MODE_SHIFT)
231 #define ECR_MODE_CFG		(07U << ECR_MODE_SHIFT)
232 #define ECR_nERRINTR		(1U << 4)
233 #define ECR_DMAEN		(1U << 3)
234 #define ECR_SERVINTR		(1U << 2)
235 #define ECR_F_FULL		(1U << 1)
236 #define ECR_F_EMPTY		(1U << 0)
237 
238 /*--- Private data -----------------------------------------------------*/
239 
240 /**
241  * enum parport_ip32_irq_mode - operation mode of interrupt handler
242  * @PARPORT_IP32_IRQ_FWD:	forward interrupt to the upper parport layer
243  * @PARPORT_IP32_IRQ_HERE:	interrupt is handled locally
244  */
245 enum parport_ip32_irq_mode { PARPORT_IP32_IRQ_FWD, PARPORT_IP32_IRQ_HERE };
246 
247 /**
248  * struct parport_ip32_private - private stuff for &struct parport
249  * @regs:		register addresses
250  * @dcr_cache:		cached contents of DCR
251  * @dcr_writable:	bit mask of writable DCR bits
252  * @pword:		number of bytes per PWord
253  * @fifo_depth:		number of PWords that FIFO will hold
254  * @readIntrThreshold:	minimum number of PWords we can read
255  *			if we get an interrupt
256  * @writeIntrThreshold:	minimum number of PWords we can write
257  *			if we get an interrupt
258  * @irq_mode:		operation mode of interrupt handler for this port
259  * @irq_complete:	mutex used to wait for an interrupt to occur
260  */
261 struct parport_ip32_private {
262 	struct parport_ip32_regs	regs;
263 	unsigned int			dcr_cache;
264 	unsigned int			dcr_writable;
265 	unsigned int			pword;
266 	unsigned int			fifo_depth;
267 	unsigned int			readIntrThreshold;
268 	unsigned int			writeIntrThreshold;
269 	enum parport_ip32_irq_mode	irq_mode;
270 	struct completion		irq_complete;
271 };
272 
273 /*--- Debug code -------------------------------------------------------*/
274 
275 /*
276  * pr_debug1 - print debug messages
277  *
278  * This is like pr_debug(), but is defined for %DEBUG_PARPORT_IP32 >= 1
279  */
280 #if DEBUG_PARPORT_IP32 >= 1
281 #	define pr_debug1(...)	printk(KERN_DEBUG __VA_ARGS__)
282 #else /* DEBUG_PARPORT_IP32 < 1 */
283 #	define pr_debug1(...)	do { } while (0)
284 #endif
285 
286 /*
287  * pr_trace, pr_trace1 - trace function calls
288  * @p:		pointer to &struct parport
289  * @fmt:	printk format string
290  * @...:	parameters for format string
291  *
292  * Macros used to trace function calls.  The given string is formatted after
293  * function name.  pr_trace() uses pr_debug(), and pr_trace1() uses
294  * pr_debug1().  __pr_trace() is the low-level macro and is not to be used
295  * directly.
296  */
297 #define __pr_trace(pr, p, fmt, ...)					\
298 	pr("%s: %s" fmt "\n",						\
299 	   ({ const struct parport *__p = (p);				\
300 		   __p ? __p->name : "parport_ip32"; }),		\
301 	   __func__ , ##__VA_ARGS__)
302 #define pr_trace(p, fmt, ...)	__pr_trace(pr_debug, p, fmt , ##__VA_ARGS__)
303 #define pr_trace1(p, fmt, ...)	__pr_trace(pr_debug1, p, fmt , ##__VA_ARGS__)
304 
305 /*
306  * __pr_probe, pr_probe - print message if @verbose_probing is true
307  * @p:		pointer to &struct parport
308  * @fmt:	printk format string
309  * @...:	parameters for format string
310  *
311  * For new lines, use pr_probe().  Use __pr_probe() for continued lines.
312  */
313 #define __pr_probe(...)							\
314 	do { if (verbose_probing) printk(__VA_ARGS__); } while (0)
315 #define pr_probe(p, fmt, ...)						\
316 	__pr_probe(KERN_INFO PPIP32 "0x%lx: " fmt, (p)->base , ##__VA_ARGS__)
317 
318 /*
319  * parport_ip32_dump_state - print register status of parport
320  * @p:		pointer to &struct parport
321  * @str:	string to add in message
322  * @show_ecp_config:	shall we dump ECP configuration registers too?
323  *
324  * This function is only here for debugging purpose, and should be used with
325  * care.  Reading the parallel port registers may have undesired side effects.
326  * Especially if @show_ecp_config is true, the parallel port is resetted.
327  * This function is only defined if %DEBUG_PARPORT_IP32 >= 2.
328  */
329 #if DEBUG_PARPORT_IP32 >= 2
330 static void parport_ip32_dump_state(struct parport *p, char *str,
331 				    unsigned int show_ecp_config)
332 {
333 	struct parport_ip32_private * const priv = p->physport->private_data;
334 	unsigned int i;
335 
336 	printk(KERN_DEBUG PPIP32 "%s: state (%s):\n", p->name, str);
337 	{
338 		static const char ecr_modes[8][4] = {"SPP", "PS2", "PPF",
339 						     "ECP", "EPP", "???",
340 						     "TST", "CFG"};
341 		unsigned int ecr = readb(priv->regs.ecr);
342 		printk(KERN_DEBUG PPIP32 "    ecr=0x%02x", ecr);
343 		printk(" %s",
344 		       ecr_modes[(ecr & ECR_MODE_MASK) >> ECR_MODE_SHIFT]);
345 		if (ecr & ECR_nERRINTR)
346 			printk(",nErrIntrEn");
347 		if (ecr & ECR_DMAEN)
348 			printk(",dmaEn");
349 		if (ecr & ECR_SERVINTR)
350 			printk(",serviceIntr");
351 		if (ecr & ECR_F_FULL)
352 			printk(",f_full");
353 		if (ecr & ECR_F_EMPTY)
354 			printk(",f_empty");
355 		printk("\n");
356 	}
357 	if (show_ecp_config) {
358 		unsigned int oecr, cnfgA, cnfgB;
359 		oecr = readb(priv->regs.ecr);
360 		writeb(ECR_MODE_PS2, priv->regs.ecr);
361 		writeb(ECR_MODE_CFG, priv->regs.ecr);
362 		cnfgA = readb(priv->regs.cnfgA);
363 		cnfgB = readb(priv->regs.cnfgB);
364 		writeb(ECR_MODE_PS2, priv->regs.ecr);
365 		writeb(oecr, priv->regs.ecr);
366 		printk(KERN_DEBUG PPIP32 "    cnfgA=0x%02x", cnfgA);
367 		printk(" ISA-%s", (cnfgA & CNFGA_IRQ) ? "Level" : "Pulses");
368 		switch (cnfgA & CNFGA_ID_MASK) {
369 		case CNFGA_ID_8:
370 			printk(",8 bits");
371 			break;
372 		case CNFGA_ID_16:
373 			printk(",16 bits");
374 			break;
375 		case CNFGA_ID_32:
376 			printk(",32 bits");
377 			break;
378 		default:
379 			printk(",unknown ID");
380 			break;
381 		}
382 		if (!(cnfgA & CNFGA_nBYTEINTRANS))
383 			printk(",ByteInTrans");
384 		if ((cnfgA & CNFGA_ID_MASK) != CNFGA_ID_8)
385 			printk(",%d byte%s left", cnfgA & CNFGA_PWORDLEFT,
386 			       ((cnfgA & CNFGA_PWORDLEFT) > 1) ? "s" : "");
387 		printk("\n");
388 		printk(KERN_DEBUG PPIP32 "    cnfgB=0x%02x", cnfgB);
389 		printk(" irq=%u,dma=%u",
390 		       (cnfgB & CNFGB_IRQ_MASK) >> CNFGB_IRQ_SHIFT,
391 		       (cnfgB & CNFGB_DMA_MASK) >> CNFGB_DMA_SHIFT);
392 		printk(",intrValue=%d", !!(cnfgB & CNFGB_INTRVAL));
393 		if (cnfgB & CNFGB_COMPRESS)
394 			printk(",compress");
395 		printk("\n");
396 	}
397 	for (i = 0; i < 2; i++) {
398 		unsigned int dcr = i ? priv->dcr_cache : readb(priv->regs.dcr);
399 		printk(KERN_DEBUG PPIP32 "    dcr(%s)=0x%02x",
400 		       i ? "soft" : "hard", dcr);
401 		printk(" %s", (dcr & DCR_DIR) ? "rev" : "fwd");
402 		if (dcr & DCR_IRQ)
403 			printk(",ackIntEn");
404 		if (!(dcr & DCR_SELECT))
405 			printk(",nSelectIn");
406 		if (dcr & DCR_nINIT)
407 			printk(",nInit");
408 		if (!(dcr & DCR_AUTOFD))
409 			printk(",nAutoFD");
410 		if (!(dcr & DCR_STROBE))
411 			printk(",nStrobe");
412 		printk("\n");
413 	}
414 #define sep (f++ ? ',' : ' ')
415 	{
416 		unsigned int f = 0;
417 		unsigned int dsr = readb(priv->regs.dsr);
418 		printk(KERN_DEBUG PPIP32 "    dsr=0x%02x", dsr);
419 		if (!(dsr & DSR_nBUSY))
420 			printk("%cBusy", sep);
421 		if (dsr & DSR_nACK)
422 			printk("%cnAck", sep);
423 		if (dsr & DSR_PERROR)
424 			printk("%cPError", sep);
425 		if (dsr & DSR_SELECT)
426 			printk("%cSelect", sep);
427 		if (dsr & DSR_nFAULT)
428 			printk("%cnFault", sep);
429 		if (!(dsr & DSR_nPRINT))
430 			printk("%c(Print)", sep);
431 		if (dsr & DSR_TIMEOUT)
432 			printk("%cTimeout", sep);
433 		printk("\n");
434 	}
435 #undef sep
436 }
437 #else /* DEBUG_PARPORT_IP32 < 2 */
438 #define parport_ip32_dump_state(...)	do { } while (0)
439 #endif
440 
441 /*
442  * CHECK_EXTRA_BITS - track and log extra bits
443  * @p:		pointer to &struct parport
444  * @b:		byte to inspect
445  * @m:		bit mask of authorized bits
446  *
447  * This is used to track and log extra bits that should not be there in
448  * parport_ip32_write_control() and parport_ip32_frob_control().  It is only
449  * defined if %DEBUG_PARPORT_IP32 >= 1.
450  */
451 #if DEBUG_PARPORT_IP32 >= 1
452 #define CHECK_EXTRA_BITS(p, b, m)					\
453 	do {								\
454 		unsigned int __b = (b), __m = (m);			\
455 		if (__b & ~__m)						\
456 			pr_debug1(PPIP32 "%s: extra bits in %s(%s): "	\
457 				  "0x%02x/0x%02x\n",			\
458 				  (p)->name, __func__, #b, __b, __m);	\
459 	} while (0)
460 #else /* DEBUG_PARPORT_IP32 < 1 */
461 #define CHECK_EXTRA_BITS(...)	do { } while (0)
462 #endif
463 
464 /*--- IP32 parallel port DMA operations --------------------------------*/
465 
466 /**
467  * struct parport_ip32_dma_data - private data needed for DMA operation
468  * @dir:	DMA direction (from or to device)
469  * @buf:	buffer physical address
470  * @len:	buffer length
471  * @next:	address of next bytes to DMA transfer
472  * @left:	number of bytes remaining
473  * @ctx:	next context to write (0: context_a; 1: context_b)
474  * @irq_on:	are the DMA IRQs currently enabled?
475  * @lock:	spinlock to protect access to the structure
476  */
477 struct parport_ip32_dma_data {
478 	enum dma_data_direction		dir;
479 	dma_addr_t			buf;
480 	dma_addr_t			next;
481 	size_t				len;
482 	size_t				left;
483 	unsigned int			ctx;
484 	unsigned int			irq_on;
485 	spinlock_t			lock;
486 };
487 static struct parport_ip32_dma_data parport_ip32_dma;
488 
489 /**
490  * parport_ip32_dma_setup_context - setup next DMA context
491  * @limit:	maximum data size for the context
492  *
493  * The alignment constraints must be verified in caller function, and the
494  * parameter @limit must be set accordingly.
495  */
496 static void parport_ip32_dma_setup_context(unsigned int limit)
497 {
498 	unsigned long flags;
499 
500 	spin_lock_irqsave(&parport_ip32_dma.lock, flags);
501 	if (parport_ip32_dma.left > 0) {
502 		/* Note: ctxreg is "volatile" here only because
503 		 * mace->perif.ctrl.parport.context_a and context_b are
504 		 * "volatile".  */
505 		volatile u64 __iomem *ctxreg = (parport_ip32_dma.ctx == 0) ?
506 			&mace->perif.ctrl.parport.context_a :
507 			&mace->perif.ctrl.parport.context_b;
508 		u64 count;
509 		u64 ctxval;
510 		if (parport_ip32_dma.left <= limit) {
511 			count = parport_ip32_dma.left;
512 			ctxval = MACEPAR_CONTEXT_LASTFLAG;
513 		} else {
514 			count = limit;
515 			ctxval = 0;
516 		}
517 
518 		pr_trace(NULL,
519 			 "(%u): 0x%04x:0x%04x, %u -> %u%s",
520 			 limit,
521 			 (unsigned int)parport_ip32_dma.buf,
522 			 (unsigned int)parport_ip32_dma.next,
523 			 (unsigned int)count,
524 			 parport_ip32_dma.ctx, ctxval ? "*" : "");
525 
526 		ctxval |= parport_ip32_dma.next &
527 			MACEPAR_CONTEXT_BASEADDR_MASK;
528 		ctxval |= ((count - 1) << MACEPAR_CONTEXT_DATALEN_SHIFT) &
529 			MACEPAR_CONTEXT_DATALEN_MASK;
530 		writeq(ctxval, ctxreg);
531 		parport_ip32_dma.next += count;
532 		parport_ip32_dma.left -= count;
533 		parport_ip32_dma.ctx ^= 1U;
534 	}
535 	/* If there is nothing more to send, disable IRQs to avoid to
536 	 * face an IRQ storm which can lock the machine.  Disable them
537 	 * only once. */
538 	if (parport_ip32_dma.left == 0 && parport_ip32_dma.irq_on) {
539 		pr_debug(PPIP32 "IRQ off (ctx)\n");
540 		disable_irq_nosync(MACEISA_PAR_CTXA_IRQ);
541 		disable_irq_nosync(MACEISA_PAR_CTXB_IRQ);
542 		parport_ip32_dma.irq_on = 0;
543 	}
544 	spin_unlock_irqrestore(&parport_ip32_dma.lock, flags);
545 }
546 
547 /**
548  * parport_ip32_dma_interrupt - DMA interrupt handler
549  * @irq:	interrupt number
550  * @dev_id:	unused
551  */
552 static irqreturn_t parport_ip32_dma_interrupt(int irq, void *dev_id)
553 {
554 	if (parport_ip32_dma.left)
555 		pr_trace(NULL, "(%d): ctx=%d", irq, parport_ip32_dma.ctx);
556 	parport_ip32_dma_setup_context(MACEPAR_CONTEXT_DATA_BOUND);
557 	return IRQ_HANDLED;
558 }
559 
560 #if DEBUG_PARPORT_IP32
561 static irqreturn_t parport_ip32_merr_interrupt(int irq, void *dev_id)
562 {
563 	pr_trace1(NULL, "(%d)", irq);
564 	return IRQ_HANDLED;
565 }
566 #endif
567 
568 /**
569  * parport_ip32_dma_start - begins a DMA transfer
570  * @dir:	DMA direction: DMA_TO_DEVICE or DMA_FROM_DEVICE
571  * @addr:	pointer to data buffer
572  * @count:	buffer size
573  *
574  * Calls to parport_ip32_dma_start() and parport_ip32_dma_stop() must be
575  * correctly balanced.
576  */
577 static int parport_ip32_dma_start(enum dma_data_direction dir,
578 				  void *addr, size_t count)
579 {
580 	unsigned int limit;
581 	u64 ctrl;
582 
583 	pr_trace(NULL, "(%d, %lu)", dir, (unsigned long)count);
584 
585 	/* FIXME - add support for DMA_FROM_DEVICE.  In this case, buffer must
586 	 * be 64 bytes aligned. */
587 	BUG_ON(dir != DMA_TO_DEVICE);
588 
589 	/* Reset DMA controller */
590 	ctrl = MACEPAR_CTLSTAT_RESET;
591 	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
592 
593 	/* DMA IRQs should normally be enabled */
594 	if (!parport_ip32_dma.irq_on) {
595 		WARN_ON(1);
596 		enable_irq(MACEISA_PAR_CTXA_IRQ);
597 		enable_irq(MACEISA_PAR_CTXB_IRQ);
598 		parport_ip32_dma.irq_on = 1;
599 	}
600 
601 	/* Prepare DMA pointers */
602 	parport_ip32_dma.dir = dir;
603 	parport_ip32_dma.buf = dma_map_single(NULL, addr, count, dir);
604 	parport_ip32_dma.len = count;
605 	parport_ip32_dma.next = parport_ip32_dma.buf;
606 	parport_ip32_dma.left = parport_ip32_dma.len;
607 	parport_ip32_dma.ctx = 0;
608 
609 	/* Setup DMA direction and first two contexts */
610 	ctrl = (dir == DMA_TO_DEVICE) ? 0 : MACEPAR_CTLSTAT_DIRECTION;
611 	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
612 	/* Single transfer should not cross a 4K page boundary */
613 	limit = MACEPAR_CONTEXT_DATA_BOUND -
614 		(parport_ip32_dma.next & (MACEPAR_CONTEXT_DATA_BOUND - 1));
615 	parport_ip32_dma_setup_context(limit);
616 	parport_ip32_dma_setup_context(MACEPAR_CONTEXT_DATA_BOUND);
617 
618 	/* Real start of DMA transfer */
619 	ctrl |= MACEPAR_CTLSTAT_ENABLE;
620 	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
621 
622 	return 0;
623 }
624 
625 /**
626  * parport_ip32_dma_stop - ends a running DMA transfer
627  *
628  * Calls to parport_ip32_dma_start() and parport_ip32_dma_stop() must be
629  * correctly balanced.
630  */
631 static void parport_ip32_dma_stop(void)
632 {
633 	u64 ctx_a;
634 	u64 ctx_b;
635 	u64 ctrl;
636 	u64 diag;
637 	size_t res[2];	/* {[0] = res_a, [1] = res_b} */
638 
639 	pr_trace(NULL, "()");
640 
641 	/* Disable IRQs */
642 	spin_lock_irq(&parport_ip32_dma.lock);
643 	if (parport_ip32_dma.irq_on) {
644 		pr_debug(PPIP32 "IRQ off (stop)\n");
645 		disable_irq_nosync(MACEISA_PAR_CTXA_IRQ);
646 		disable_irq_nosync(MACEISA_PAR_CTXB_IRQ);
647 		parport_ip32_dma.irq_on = 0;
648 	}
649 	spin_unlock_irq(&parport_ip32_dma.lock);
650 	/* Force IRQ synchronization, even if the IRQs were disabled
651 	 * elsewhere. */
652 	synchronize_irq(MACEISA_PAR_CTXA_IRQ);
653 	synchronize_irq(MACEISA_PAR_CTXB_IRQ);
654 
655 	/* Stop DMA transfer */
656 	ctrl = readq(&mace->perif.ctrl.parport.cntlstat);
657 	ctrl &= ~MACEPAR_CTLSTAT_ENABLE;
658 	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
659 
660 	/* Adjust residue (parport_ip32_dma.left) */
661 	ctx_a = readq(&mace->perif.ctrl.parport.context_a);
662 	ctx_b = readq(&mace->perif.ctrl.parport.context_b);
663 	ctrl = readq(&mace->perif.ctrl.parport.cntlstat);
664 	diag = readq(&mace->perif.ctrl.parport.diagnostic);
665 	res[0] = (ctrl & MACEPAR_CTLSTAT_CTXA_VALID) ?
666 		1 + ((ctx_a & MACEPAR_CONTEXT_DATALEN_MASK) >>
667 		     MACEPAR_CONTEXT_DATALEN_SHIFT) :
668 		0;
669 	res[1] = (ctrl & MACEPAR_CTLSTAT_CTXB_VALID) ?
670 		1 + ((ctx_b & MACEPAR_CONTEXT_DATALEN_MASK) >>
671 		     MACEPAR_CONTEXT_DATALEN_SHIFT) :
672 		0;
673 	if (diag & MACEPAR_DIAG_DMACTIVE)
674 		res[(diag & MACEPAR_DIAG_CTXINUSE) != 0] =
675 			1 + ((diag & MACEPAR_DIAG_CTRMASK) >>
676 			     MACEPAR_DIAG_CTRSHIFT);
677 	parport_ip32_dma.left += res[0] + res[1];
678 
679 	/* Reset DMA controller, and re-enable IRQs */
680 	ctrl = MACEPAR_CTLSTAT_RESET;
681 	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
682 	pr_debug(PPIP32 "IRQ on (stop)\n");
683 	enable_irq(MACEISA_PAR_CTXA_IRQ);
684 	enable_irq(MACEISA_PAR_CTXB_IRQ);
685 	parport_ip32_dma.irq_on = 1;
686 
687 	dma_unmap_single(NULL, parport_ip32_dma.buf, parport_ip32_dma.len,
688 			 parport_ip32_dma.dir);
689 }
690 
691 /**
692  * parport_ip32_dma_get_residue - get residue from last DMA transfer
693  *
694  * Returns the number of bytes remaining from last DMA transfer.
695  */
696 static inline size_t parport_ip32_dma_get_residue(void)
697 {
698 	return parport_ip32_dma.left;
699 }
700 
701 /**
702  * parport_ip32_dma_register - initialize DMA engine
703  *
704  * Returns zero for success.
705  */
706 static int parport_ip32_dma_register(void)
707 {
708 	int err;
709 
710 	spin_lock_init(&parport_ip32_dma.lock);
711 	parport_ip32_dma.irq_on = 1;
712 
713 	/* Reset DMA controller */
714 	writeq(MACEPAR_CTLSTAT_RESET, &mace->perif.ctrl.parport.cntlstat);
715 
716 	/* Request IRQs */
717 	err = request_irq(MACEISA_PAR_CTXA_IRQ, parport_ip32_dma_interrupt,
718 			  0, "parport_ip32", NULL);
719 	if (err)
720 		goto fail_a;
721 	err = request_irq(MACEISA_PAR_CTXB_IRQ, parport_ip32_dma_interrupt,
722 			  0, "parport_ip32", NULL);
723 	if (err)
724 		goto fail_b;
725 #if DEBUG_PARPORT_IP32
726 	/* FIXME - what is this IRQ for? */
727 	err = request_irq(MACEISA_PAR_MERR_IRQ, parport_ip32_merr_interrupt,
728 			  0, "parport_ip32", NULL);
729 	if (err)
730 		goto fail_merr;
731 #endif
732 	return 0;
733 
734 #if DEBUG_PARPORT_IP32
735 fail_merr:
736 	free_irq(MACEISA_PAR_CTXB_IRQ, NULL);
737 #endif
738 fail_b:
739 	free_irq(MACEISA_PAR_CTXA_IRQ, NULL);
740 fail_a:
741 	return err;
742 }
743 
744 /**
745  * parport_ip32_dma_unregister - release and free resources for DMA engine
746  */
747 static void parport_ip32_dma_unregister(void)
748 {
749 #if DEBUG_PARPORT_IP32
750 	free_irq(MACEISA_PAR_MERR_IRQ, NULL);
751 #endif
752 	free_irq(MACEISA_PAR_CTXB_IRQ, NULL);
753 	free_irq(MACEISA_PAR_CTXA_IRQ, NULL);
754 }
755 
756 /*--- Interrupt handlers and associates --------------------------------*/
757 
758 /**
759  * parport_ip32_wakeup - wakes up code waiting for an interrupt
760  * @p:		pointer to &struct parport
761  */
762 static inline void parport_ip32_wakeup(struct parport *p)
763 {
764 	struct parport_ip32_private * const priv = p->physport->private_data;
765 	complete(&priv->irq_complete);
766 }
767 
768 /**
769  * parport_ip32_interrupt - interrupt handler
770  * @irq:	interrupt number
771  * @dev_id:	pointer to &struct parport
772  *
773  * Caught interrupts are forwarded to the upper parport layer if IRQ_mode is
774  * %PARPORT_IP32_IRQ_FWD.
775  */
776 static irqreturn_t parport_ip32_interrupt(int irq, void *dev_id)
777 {
778 	struct parport * const p = dev_id;
779 	struct parport_ip32_private * const priv = p->physport->private_data;
780 	enum parport_ip32_irq_mode irq_mode = priv->irq_mode;
781 
782 	switch (irq_mode) {
783 	case PARPORT_IP32_IRQ_FWD:
784 		return parport_irq_handler(irq, dev_id);
785 
786 	case PARPORT_IP32_IRQ_HERE:
787 		parport_ip32_wakeup(p);
788 		break;
789 	}
790 
791 	return IRQ_HANDLED;
792 }
793 
794 /*--- Some utility function to manipulate ECR register -----------------*/
795 
796 /**
797  * parport_ip32_read_econtrol - read contents of the ECR register
798  * @p:		pointer to &struct parport
799  */
800 static inline unsigned int parport_ip32_read_econtrol(struct parport *p)
801 {
802 	struct parport_ip32_private * const priv = p->physport->private_data;
803 	return readb(priv->regs.ecr);
804 }
805 
806 /**
807  * parport_ip32_write_econtrol - write new contents to the ECR register
808  * @p:		pointer to &struct parport
809  * @c:		new value to write
810  */
811 static inline void parport_ip32_write_econtrol(struct parport *p,
812 					       unsigned int c)
813 {
814 	struct parport_ip32_private * const priv = p->physport->private_data;
815 	writeb(c, priv->regs.ecr);
816 }
817 
818 /**
819  * parport_ip32_frob_econtrol - change bits from the ECR register
820  * @p:		pointer to &struct parport
821  * @mask:	bit mask of bits to change
822  * @val:	new value for changed bits
823  *
824  * Read from the ECR, mask out the bits in @mask, exclusive-or with the bits
825  * in @val, and write the result to the ECR.
826  */
827 static inline void parport_ip32_frob_econtrol(struct parport *p,
828 					      unsigned int mask,
829 					      unsigned int val)
830 {
831 	unsigned int c;
832 	c = (parport_ip32_read_econtrol(p) & ~mask) ^ val;
833 	parport_ip32_write_econtrol(p, c);
834 }
835 
836 /**
837  * parport_ip32_set_mode - change mode of ECP port
838  * @p:		pointer to &struct parport
839  * @mode:	new mode to write in ECR
840  *
841  * ECR is reset in a sane state (interrupts and DMA disabled), and placed in
842  * mode @mode.  Go through PS2 mode if needed.
843  */
844 static void parport_ip32_set_mode(struct parport *p, unsigned int mode)
845 {
846 	unsigned int omode;
847 
848 	mode &= ECR_MODE_MASK;
849 	omode = parport_ip32_read_econtrol(p) & ECR_MODE_MASK;
850 
851 	if (!(mode == ECR_MODE_SPP || mode == ECR_MODE_PS2
852 	      || omode == ECR_MODE_SPP || omode == ECR_MODE_PS2)) {
853 		/* We have to go through PS2 mode */
854 		unsigned int ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
855 		parport_ip32_write_econtrol(p, ecr);
856 	}
857 	parport_ip32_write_econtrol(p, mode | ECR_nERRINTR | ECR_SERVINTR);
858 }
859 
860 /*--- Basic functions needed for parport -------------------------------*/
861 
862 /**
863  * parport_ip32_read_data - return current contents of the DATA register
864  * @p:		pointer to &struct parport
865  */
866 static inline unsigned char parport_ip32_read_data(struct parport *p)
867 {
868 	struct parport_ip32_private * const priv = p->physport->private_data;
869 	return readb(priv->regs.data);
870 }
871 
872 /**
873  * parport_ip32_write_data - set new contents for the DATA register
874  * @p:		pointer to &struct parport
875  * @d:		new value to write
876  */
877 static inline void parport_ip32_write_data(struct parport *p, unsigned char d)
878 {
879 	struct parport_ip32_private * const priv = p->physport->private_data;
880 	writeb(d, priv->regs.data);
881 }
882 
883 /**
884  * parport_ip32_read_status - return current contents of the DSR register
885  * @p:		pointer to &struct parport
886  */
887 static inline unsigned char parport_ip32_read_status(struct parport *p)
888 {
889 	struct parport_ip32_private * const priv = p->physport->private_data;
890 	return readb(priv->regs.dsr);
891 }
892 
893 /**
894  * __parport_ip32_read_control - return cached contents of the DCR register
895  * @p:		pointer to &struct parport
896  */
897 static inline unsigned int __parport_ip32_read_control(struct parport *p)
898 {
899 	struct parport_ip32_private * const priv = p->physport->private_data;
900 	return priv->dcr_cache; /* use soft copy */
901 }
902 
903 /**
904  * __parport_ip32_write_control - set new contents for the DCR register
905  * @p:		pointer to &struct parport
906  * @c:		new value to write
907  */
908 static inline void __parport_ip32_write_control(struct parport *p,
909 						unsigned int c)
910 {
911 	struct parport_ip32_private * const priv = p->physport->private_data;
912 	CHECK_EXTRA_BITS(p, c, priv->dcr_writable);
913 	c &= priv->dcr_writable; /* only writable bits */
914 	writeb(c, priv->regs.dcr);
915 	priv->dcr_cache = c;		/* update soft copy */
916 }
917 
918 /**
919  * __parport_ip32_frob_control - change bits from the DCR register
920  * @p:		pointer to &struct parport
921  * @mask:	bit mask of bits to change
922  * @val:	new value for changed bits
923  *
924  * This is equivalent to read from the DCR, mask out the bits in @mask,
925  * exclusive-or with the bits in @val, and write the result to the DCR.
926  * Actually, the cached contents of the DCR is used.
927  */
928 static inline void __parport_ip32_frob_control(struct parport *p,
929 					       unsigned int mask,
930 					       unsigned int val)
931 {
932 	unsigned int c;
933 	c = (__parport_ip32_read_control(p) & ~mask) ^ val;
934 	__parport_ip32_write_control(p, c);
935 }
936 
937 /**
938  * parport_ip32_read_control - return cached contents of the DCR register
939  * @p:		pointer to &struct parport
940  *
941  * The return value is masked so as to only return the value of %DCR_STROBE,
942  * %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
943  */
944 static inline unsigned char parport_ip32_read_control(struct parport *p)
945 {
946 	const unsigned int rm =
947 		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
948 	return __parport_ip32_read_control(p) & rm;
949 }
950 
951 /**
952  * parport_ip32_write_control - set new contents for the DCR register
953  * @p:		pointer to &struct parport
954  * @c:		new value to write
955  *
956  * The value is masked so as to only change the value of %DCR_STROBE,
957  * %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
958  */
959 static inline void parport_ip32_write_control(struct parport *p,
960 					      unsigned char c)
961 {
962 	const unsigned int wm =
963 		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
964 	CHECK_EXTRA_BITS(p, c, wm);
965 	__parport_ip32_frob_control(p, wm, c & wm);
966 }
967 
968 /**
969  * parport_ip32_frob_control - change bits from the DCR register
970  * @p:		pointer to &struct parport
971  * @mask:	bit mask of bits to change
972  * @val:	new value for changed bits
973  *
974  * This differs from __parport_ip32_frob_control() in that it only allows to
975  * change the value of %DCR_STROBE, %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
976  */
977 static inline unsigned char parport_ip32_frob_control(struct parport *p,
978 						      unsigned char mask,
979 						      unsigned char val)
980 {
981 	const unsigned int wm =
982 		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
983 	CHECK_EXTRA_BITS(p, mask, wm);
984 	CHECK_EXTRA_BITS(p, val, wm);
985 	__parport_ip32_frob_control(p, mask & wm, val & wm);
986 	return parport_ip32_read_control(p);
987 }
988 
989 /**
990  * parport_ip32_disable_irq - disable interrupts on the rising edge of nACK
991  * @p:		pointer to &struct parport
992  */
993 static inline void parport_ip32_disable_irq(struct parport *p)
994 {
995 	__parport_ip32_frob_control(p, DCR_IRQ, 0);
996 }
997 
998 /**
999  * parport_ip32_enable_irq - enable interrupts on the rising edge of nACK
1000  * @p:		pointer to &struct parport
1001  */
1002 static inline void parport_ip32_enable_irq(struct parport *p)
1003 {
1004 	__parport_ip32_frob_control(p, DCR_IRQ, DCR_IRQ);
1005 }
1006 
1007 /**
1008  * parport_ip32_data_forward - enable host-to-peripheral communications
1009  * @p:		pointer to &struct parport
1010  *
1011  * Enable the data line drivers, for 8-bit host-to-peripheral communications.
1012  */
1013 static inline void parport_ip32_data_forward(struct parport *p)
1014 {
1015 	__parport_ip32_frob_control(p, DCR_DIR, 0);
1016 }
1017 
1018 /**
1019  * parport_ip32_data_reverse - enable peripheral-to-host communications
1020  * @p:		pointer to &struct parport
1021  *
1022  * Place the data bus in a high impedance state, if @p->modes has the
1023  * PARPORT_MODE_TRISTATE bit set.
1024  */
1025 static inline void parport_ip32_data_reverse(struct parport *p)
1026 {
1027 	__parport_ip32_frob_control(p, DCR_DIR, DCR_DIR);
1028 }
1029 
1030 /**
1031  * parport_ip32_init_state - for core parport code
1032  * @dev:	pointer to &struct pardevice
1033  * @s:		pointer to &struct parport_state to initialize
1034  */
1035 static void parport_ip32_init_state(struct pardevice *dev,
1036 				    struct parport_state *s)
1037 {
1038 	s->u.ip32.dcr = DCR_SELECT | DCR_nINIT;
1039 	s->u.ip32.ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
1040 }
1041 
1042 /**
1043  * parport_ip32_save_state - for core parport code
1044  * @p:		pointer to &struct parport
1045  * @s:		pointer to &struct parport_state to save state to
1046  */
1047 static void parport_ip32_save_state(struct parport *p,
1048 				    struct parport_state *s)
1049 {
1050 	s->u.ip32.dcr = __parport_ip32_read_control(p);
1051 	s->u.ip32.ecr = parport_ip32_read_econtrol(p);
1052 }
1053 
1054 /**
1055  * parport_ip32_restore_state - for core parport code
1056  * @p:		pointer to &struct parport
1057  * @s:		pointer to &struct parport_state to restore state from
1058  */
1059 static void parport_ip32_restore_state(struct parport *p,
1060 				       struct parport_state *s)
1061 {
1062 	parport_ip32_set_mode(p, s->u.ip32.ecr & ECR_MODE_MASK);
1063 	parport_ip32_write_econtrol(p, s->u.ip32.ecr);
1064 	__parport_ip32_write_control(p, s->u.ip32.dcr);
1065 }
1066 
1067 /*--- EPP mode functions -----------------------------------------------*/
1068 
1069 /**
1070  * parport_ip32_clear_epp_timeout - clear Timeout bit in EPP mode
1071  * @p:		pointer to &struct parport
1072  *
1073  * Returns 1 if the Timeout bit is clear, and 0 otherwise.
1074  */
1075 static unsigned int parport_ip32_clear_epp_timeout(struct parport *p)
1076 {
1077 	struct parport_ip32_private * const priv = p->physport->private_data;
1078 	unsigned int cleared;
1079 
1080 	if (!(parport_ip32_read_status(p) & DSR_TIMEOUT))
1081 		cleared = 1;
1082 	else {
1083 		unsigned int r;
1084 		/* To clear timeout some chips require double read */
1085 		parport_ip32_read_status(p);
1086 		r = parport_ip32_read_status(p);
1087 		/* Some reset by writing 1 */
1088 		writeb(r | DSR_TIMEOUT, priv->regs.dsr);
1089 		/* Others by writing 0 */
1090 		writeb(r & ~DSR_TIMEOUT, priv->regs.dsr);
1091 
1092 		r = parport_ip32_read_status(p);
1093 		cleared = !(r & DSR_TIMEOUT);
1094 	}
1095 
1096 	pr_trace(p, "(): %s", cleared ? "cleared" : "failed");
1097 	return cleared;
1098 }
1099 
1100 /**
1101  * parport_ip32_epp_read - generic EPP read function
1102  * @eppreg:	I/O register to read from
1103  * @p:		pointer to &struct parport
1104  * @buf:	buffer to store read data
1105  * @len:	length of buffer @buf
1106  * @flags:	may be PARPORT_EPP_FAST
1107  */
1108 static size_t parport_ip32_epp_read(void __iomem *eppreg,
1109 				    struct parport *p, void *buf,
1110 				    size_t len, int flags)
1111 {
1112 	struct parport_ip32_private * const priv = p->physport->private_data;
1113 	size_t got;
1114 	parport_ip32_set_mode(p, ECR_MODE_EPP);
1115 	parport_ip32_data_reverse(p);
1116 	parport_ip32_write_control(p, DCR_nINIT);
1117 	if ((flags & PARPORT_EPP_FAST) && (len > 1)) {
1118 		readsb(eppreg, buf, len);
1119 		if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1120 			parport_ip32_clear_epp_timeout(p);
1121 			return -EIO;
1122 		}
1123 		got = len;
1124 	} else {
1125 		u8 *bufp = buf;
1126 		for (got = 0; got < len; got++) {
1127 			*bufp++ = readb(eppreg);
1128 			if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1129 				parport_ip32_clear_epp_timeout(p);
1130 				break;
1131 			}
1132 		}
1133 	}
1134 	parport_ip32_data_forward(p);
1135 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1136 	return got;
1137 }
1138 
1139 /**
1140  * parport_ip32_epp_write - generic EPP write function
1141  * @eppreg:	I/O register to write to
1142  * @p:		pointer to &struct parport
1143  * @buf:	buffer of data to write
1144  * @len:	length of buffer @buf
1145  * @flags:	may be PARPORT_EPP_FAST
1146  */
1147 static size_t parport_ip32_epp_write(void __iomem *eppreg,
1148 				     struct parport *p, const void *buf,
1149 				     size_t len, int flags)
1150 {
1151 	struct parport_ip32_private * const priv = p->physport->private_data;
1152 	size_t written;
1153 	parport_ip32_set_mode(p, ECR_MODE_EPP);
1154 	parport_ip32_data_forward(p);
1155 	parport_ip32_write_control(p, DCR_nINIT);
1156 	if ((flags & PARPORT_EPP_FAST) && (len > 1)) {
1157 		writesb(eppreg, buf, len);
1158 		if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1159 			parport_ip32_clear_epp_timeout(p);
1160 			return -EIO;
1161 		}
1162 		written = len;
1163 	} else {
1164 		const u8 *bufp = buf;
1165 		for (written = 0; written < len; written++) {
1166 			writeb(*bufp++, eppreg);
1167 			if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1168 				parport_ip32_clear_epp_timeout(p);
1169 				break;
1170 			}
1171 		}
1172 	}
1173 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1174 	return written;
1175 }
1176 
1177 /**
1178  * parport_ip32_epp_read_data - read a block of data in EPP mode
1179  * @p:		pointer to &struct parport
1180  * @buf:	buffer to store read data
1181  * @len:	length of buffer @buf
1182  * @flags:	may be PARPORT_EPP_FAST
1183  */
1184 static size_t parport_ip32_epp_read_data(struct parport *p, void *buf,
1185 					 size_t len, int flags)
1186 {
1187 	struct parport_ip32_private * const priv = p->physport->private_data;
1188 	return parport_ip32_epp_read(priv->regs.eppData0, p, buf, len, flags);
1189 }
1190 
1191 /**
1192  * parport_ip32_epp_write_data - write a block of data in EPP mode
1193  * @p:		pointer to &struct parport
1194  * @buf:	buffer of data to write
1195  * @len:	length of buffer @buf
1196  * @flags:	may be PARPORT_EPP_FAST
1197  */
1198 static size_t parport_ip32_epp_write_data(struct parport *p, const void *buf,
1199 					  size_t len, int flags)
1200 {
1201 	struct parport_ip32_private * const priv = p->physport->private_data;
1202 	return parport_ip32_epp_write(priv->regs.eppData0, p, buf, len, flags);
1203 }
1204 
1205 /**
1206  * parport_ip32_epp_read_addr - read a block of addresses in EPP mode
1207  * @p:		pointer to &struct parport
1208  * @buf:	buffer to store read data
1209  * @len:	length of buffer @buf
1210  * @flags:	may be PARPORT_EPP_FAST
1211  */
1212 static size_t parport_ip32_epp_read_addr(struct parport *p, void *buf,
1213 					 size_t len, int flags)
1214 {
1215 	struct parport_ip32_private * const priv = p->physport->private_data;
1216 	return parport_ip32_epp_read(priv->regs.eppAddr, p, buf, len, flags);
1217 }
1218 
1219 /**
1220  * parport_ip32_epp_write_addr - write a block of addresses in EPP mode
1221  * @p:		pointer to &struct parport
1222  * @buf:	buffer of data to write
1223  * @len:	length of buffer @buf
1224  * @flags:	may be PARPORT_EPP_FAST
1225  */
1226 static size_t parport_ip32_epp_write_addr(struct parport *p, const void *buf,
1227 					  size_t len, int flags)
1228 {
1229 	struct parport_ip32_private * const priv = p->physport->private_data;
1230 	return parport_ip32_epp_write(priv->regs.eppAddr, p, buf, len, flags);
1231 }
1232 
1233 /*--- ECP mode functions (FIFO) ----------------------------------------*/
1234 
1235 /**
1236  * parport_ip32_fifo_wait_break - check if the waiting function should return
1237  * @p:		pointer to &struct parport
1238  * @expire:	timeout expiring date, in jiffies
1239  *
1240  * parport_ip32_fifo_wait_break() checks if the waiting function should return
1241  * immediately or not.  The break conditions are:
1242  *	- expired timeout;
1243  *	- a pending signal;
1244  *	- nFault asserted low.
1245  * This function also calls cond_resched().
1246  */
1247 static unsigned int parport_ip32_fifo_wait_break(struct parport *p,
1248 						 unsigned long expire)
1249 {
1250 	cond_resched();
1251 	if (time_after(jiffies, expire)) {
1252 		pr_debug1(PPIP32 "%s: FIFO write timed out\n", p->name);
1253 		return 1;
1254 	}
1255 	if (signal_pending(current)) {
1256 		pr_debug1(PPIP32 "%s: Signal pending\n", p->name);
1257 		return 1;
1258 	}
1259 	if (!(parport_ip32_read_status(p) & DSR_nFAULT)) {
1260 		pr_debug1(PPIP32 "%s: nFault asserted low\n", p->name);
1261 		return 1;
1262 	}
1263 	return 0;
1264 }
1265 
1266 /**
1267  * parport_ip32_fwp_wait_polling - wait for FIFO to empty (polling)
1268  * @p:		pointer to &struct parport
1269  *
1270  * Returns the number of bytes that can safely be written in the FIFO.  A
1271  * return value of zero means that the calling function should terminate as
1272  * fast as possible.
1273  */
1274 static unsigned int parport_ip32_fwp_wait_polling(struct parport *p)
1275 {
1276 	struct parport_ip32_private * const priv = p->physport->private_data;
1277 	struct parport * const physport = p->physport;
1278 	unsigned long expire;
1279 	unsigned int count;
1280 	unsigned int ecr;
1281 
1282 	expire = jiffies + physport->cad->timeout;
1283 	count = 0;
1284 	while (1) {
1285 		if (parport_ip32_fifo_wait_break(p, expire))
1286 			break;
1287 
1288 		/* Check FIFO state.  We do nothing when the FIFO is nor full,
1289 		 * nor empty.  It appears that the FIFO full bit is not always
1290 		 * reliable, the FIFO state is sometimes wrongly reported, and
1291 		 * the chip gets confused if we give it another byte. */
1292 		ecr = parport_ip32_read_econtrol(p);
1293 		if (ecr & ECR_F_EMPTY) {
1294 			/* FIFO is empty, fill it up */
1295 			count = priv->fifo_depth;
1296 			break;
1297 		}
1298 
1299 		/* Wait a moment... */
1300 		udelay(FIFO_POLLING_INTERVAL);
1301 	} /* while (1) */
1302 
1303 	return count;
1304 }
1305 
1306 /**
1307  * parport_ip32_fwp_wait_interrupt - wait for FIFO to empty (interrupt-driven)
1308  * @p:		pointer to &struct parport
1309  *
1310  * Returns the number of bytes that can safely be written in the FIFO.  A
1311  * return value of zero means that the calling function should terminate as
1312  * fast as possible.
1313  */
1314 static unsigned int parport_ip32_fwp_wait_interrupt(struct parport *p)
1315 {
1316 	static unsigned int lost_interrupt = 0;
1317 	struct parport_ip32_private * const priv = p->physport->private_data;
1318 	struct parport * const physport = p->physport;
1319 	unsigned long nfault_timeout;
1320 	unsigned long expire;
1321 	unsigned int count;
1322 	unsigned int ecr;
1323 
1324 	nfault_timeout = min((unsigned long)physport->cad->timeout,
1325 			     msecs_to_jiffies(FIFO_NFAULT_TIMEOUT));
1326 	expire = jiffies + physport->cad->timeout;
1327 	count = 0;
1328 	while (1) {
1329 		if (parport_ip32_fifo_wait_break(p, expire))
1330 			break;
1331 
1332 		/* Initialize mutex used to take interrupts into account */
1333 		INIT_COMPLETION(priv->irq_complete);
1334 
1335 		/* Enable serviceIntr */
1336 		parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
1337 
1338 		/* Enabling serviceIntr while the FIFO is empty does not
1339 		 * always generate an interrupt, so check for emptiness
1340 		 * now. */
1341 		ecr = parport_ip32_read_econtrol(p);
1342 		if (!(ecr & ECR_F_EMPTY)) {
1343 			/* FIFO is not empty: wait for an interrupt or a
1344 			 * timeout to occur */
1345 			wait_for_completion_interruptible_timeout(
1346 				&priv->irq_complete, nfault_timeout);
1347 			ecr = parport_ip32_read_econtrol(p);
1348 			if ((ecr & ECR_F_EMPTY) && !(ecr & ECR_SERVINTR)
1349 			    && !lost_interrupt) {
1350 				printk(KERN_WARNING PPIP32
1351 				       "%s: lost interrupt in %s\n",
1352 				       p->name, __func__);
1353 				lost_interrupt = 1;
1354 			}
1355 		}
1356 
1357 		/* Disable serviceIntr */
1358 		parport_ip32_frob_econtrol(p, ECR_SERVINTR, ECR_SERVINTR);
1359 
1360 		/* Check FIFO state */
1361 		if (ecr & ECR_F_EMPTY) {
1362 			/* FIFO is empty, fill it up */
1363 			count = priv->fifo_depth;
1364 			break;
1365 		} else if (ecr & ECR_SERVINTR) {
1366 			/* FIFO is not empty, but we know that can safely push
1367 			 * writeIntrThreshold bytes into it */
1368 			count = priv->writeIntrThreshold;
1369 			break;
1370 		}
1371 		/* FIFO is not empty, and we did not get any interrupt.
1372 		 * Either it's time to check for nFault, or a signal is
1373 		 * pending.  This is verified in
1374 		 * parport_ip32_fifo_wait_break(), so we continue the loop. */
1375 	} /* while (1) */
1376 
1377 	return count;
1378 }
1379 
1380 /**
1381  * parport_ip32_fifo_write_block_pio - write a block of data (PIO mode)
1382  * @p:		pointer to &struct parport
1383  * @buf:	buffer of data to write
1384  * @len:	length of buffer @buf
1385  *
1386  * Uses PIO to write the contents of the buffer @buf into the parallel port
1387  * FIFO.  Returns the number of bytes that were actually written.  It can work
1388  * with or without the help of interrupts.  The parallel port must be
1389  * correctly initialized before calling parport_ip32_fifo_write_block_pio().
1390  */
1391 static size_t parport_ip32_fifo_write_block_pio(struct parport *p,
1392 						const void *buf, size_t len)
1393 {
1394 	struct parport_ip32_private * const priv = p->physport->private_data;
1395 	const u8 *bufp = buf;
1396 	size_t left = len;
1397 
1398 	priv->irq_mode = PARPORT_IP32_IRQ_HERE;
1399 
1400 	while (left > 0) {
1401 		unsigned int count;
1402 
1403 		count = (p->irq == PARPORT_IRQ_NONE) ?
1404 			parport_ip32_fwp_wait_polling(p) :
1405 			parport_ip32_fwp_wait_interrupt(p);
1406 		if (count == 0)
1407 			break;	/* Transmission should be stopped */
1408 		if (count > left)
1409 			count = left;
1410 		if (count == 1) {
1411 			writeb(*bufp, priv->regs.fifo);
1412 			bufp++, left--;
1413 		} else {
1414 			writesb(priv->regs.fifo, bufp, count);
1415 			bufp += count, left -= count;
1416 		}
1417 	}
1418 
1419 	priv->irq_mode = PARPORT_IP32_IRQ_FWD;
1420 
1421 	return len - left;
1422 }
1423 
1424 /**
1425  * parport_ip32_fifo_write_block_dma - write a block of data (DMA mode)
1426  * @p:		pointer to &struct parport
1427  * @buf:	buffer of data to write
1428  * @len:	length of buffer @buf
1429  *
1430  * Uses DMA to write the contents of the buffer @buf into the parallel port
1431  * FIFO.  Returns the number of bytes that were actually written.  The
1432  * parallel port must be correctly initialized before calling
1433  * parport_ip32_fifo_write_block_dma().
1434  */
1435 static size_t parport_ip32_fifo_write_block_dma(struct parport *p,
1436 						const void *buf, size_t len)
1437 {
1438 	struct parport_ip32_private * const priv = p->physport->private_data;
1439 	struct parport * const physport = p->physport;
1440 	unsigned long nfault_timeout;
1441 	unsigned long expire;
1442 	size_t written;
1443 	unsigned int ecr;
1444 
1445 	priv->irq_mode = PARPORT_IP32_IRQ_HERE;
1446 
1447 	parport_ip32_dma_start(DMA_TO_DEVICE, (void *)buf, len);
1448 	INIT_COMPLETION(priv->irq_complete);
1449 	parport_ip32_frob_econtrol(p, ECR_DMAEN | ECR_SERVINTR, ECR_DMAEN);
1450 
1451 	nfault_timeout = min((unsigned long)physport->cad->timeout,
1452 			     msecs_to_jiffies(FIFO_NFAULT_TIMEOUT));
1453 	expire = jiffies + physport->cad->timeout;
1454 	while (1) {
1455 		if (parport_ip32_fifo_wait_break(p, expire))
1456 			break;
1457 		wait_for_completion_interruptible_timeout(&priv->irq_complete,
1458 							  nfault_timeout);
1459 		ecr = parport_ip32_read_econtrol(p);
1460 		if (ecr & ECR_SERVINTR)
1461 			break;	/* DMA transfer just finished */
1462 	}
1463 	parport_ip32_dma_stop();
1464 	written = len - parport_ip32_dma_get_residue();
1465 
1466 	priv->irq_mode = PARPORT_IP32_IRQ_FWD;
1467 
1468 	return written;
1469 }
1470 
1471 /**
1472  * parport_ip32_fifo_write_block - write a block of data
1473  * @p:		pointer to &struct parport
1474  * @buf:	buffer of data to write
1475  * @len:	length of buffer @buf
1476  *
1477  * Uses PIO or DMA to write the contents of the buffer @buf into the parallel
1478  * p FIFO.  Returns the number of bytes that were actually written.
1479  */
1480 static size_t parport_ip32_fifo_write_block(struct parport *p,
1481 					    const void *buf, size_t len)
1482 {
1483 	size_t written = 0;
1484 	if (len)
1485 		/* FIXME - Maybe some threshold value should be set for @len
1486 		 * under which we revert to PIO mode? */
1487 		written = (p->modes & PARPORT_MODE_DMA) ?
1488 			parport_ip32_fifo_write_block_dma(p, buf, len) :
1489 			parport_ip32_fifo_write_block_pio(p, buf, len);
1490 	return written;
1491 }
1492 
1493 /**
1494  * parport_ip32_drain_fifo - wait for FIFO to empty
1495  * @p:		pointer to &struct parport
1496  * @timeout:	timeout, in jiffies
1497  *
1498  * This function waits for FIFO to empty.  It returns 1 when FIFO is empty, or
1499  * 0 if the timeout @timeout is reached before, or if a signal is pending.
1500  */
1501 static unsigned int parport_ip32_drain_fifo(struct parport *p,
1502 					    unsigned long timeout)
1503 {
1504 	unsigned long expire = jiffies + timeout;
1505 	unsigned int polling_interval;
1506 	unsigned int counter;
1507 
1508 	/* Busy wait for approx. 200us */
1509 	for (counter = 0; counter < 40; counter++) {
1510 		if (parport_ip32_read_econtrol(p) & ECR_F_EMPTY)
1511 			break;
1512 		if (time_after(jiffies, expire))
1513 			break;
1514 		if (signal_pending(current))
1515 			break;
1516 		udelay(5);
1517 	}
1518 	/* Poll slowly.  Polling interval starts with 1 millisecond, and is
1519 	 * increased exponentially until 128.  */
1520 	polling_interval = 1; /* msecs */
1521 	while (!(parport_ip32_read_econtrol(p) & ECR_F_EMPTY)) {
1522 		if (time_after_eq(jiffies, expire))
1523 			break;
1524 		msleep_interruptible(polling_interval);
1525 		if (signal_pending(current))
1526 			break;
1527 		if (polling_interval < 128)
1528 			polling_interval *= 2;
1529 	}
1530 
1531 	return !!(parport_ip32_read_econtrol(p) & ECR_F_EMPTY);
1532 }
1533 
1534 /**
1535  * parport_ip32_get_fifo_residue - reset FIFO
1536  * @p:		pointer to &struct parport
1537  * @mode:	current operation mode (ECR_MODE_PPF or ECR_MODE_ECP)
1538  *
1539  * This function resets FIFO, and returns the number of bytes remaining in it.
1540  */
1541 static unsigned int parport_ip32_get_fifo_residue(struct parport *p,
1542 						  unsigned int mode)
1543 {
1544 	struct parport_ip32_private * const priv = p->physport->private_data;
1545 	unsigned int residue;
1546 	unsigned int cnfga;
1547 
1548 	/* FIXME - We are missing one byte if the printer is off-line.  I
1549 	 * don't know how to detect this.  It looks that the full bit is not
1550 	 * always reliable.  For the moment, the problem is avoided in most
1551 	 * cases by testing for BUSY in parport_ip32_compat_write_data().
1552 	 */
1553 	if (parport_ip32_read_econtrol(p) & ECR_F_EMPTY)
1554 		residue = 0;
1555 	else {
1556 		pr_debug1(PPIP32 "%s: FIFO is stuck\n", p->name);
1557 
1558 		/* Stop all transfers.
1559 		 *
1560 		 * Microsoft's document instructs to drive DCR_STROBE to 0,
1561 		 * but it doesn't work (at least in Compatibility mode, not
1562 		 * tested in ECP mode).  Switching directly to Test mode (as
1563 		 * in parport_pc) is not an option: it does confuse the port,
1564 		 * ECP service interrupts are no more working after that.  A
1565 		 * hard reset is then needed to revert to a sane state.
1566 		 *
1567 		 * Let's hope that the FIFO is really stuck and that the
1568 		 * peripheral doesn't wake up now.
1569 		 */
1570 		parport_ip32_frob_control(p, DCR_STROBE, 0);
1571 
1572 		/* Fill up FIFO */
1573 		for (residue = priv->fifo_depth; residue > 0; residue--) {
1574 			if (parport_ip32_read_econtrol(p) & ECR_F_FULL)
1575 				break;
1576 			writeb(0x00, priv->regs.fifo);
1577 		}
1578 	}
1579 	if (residue)
1580 		pr_debug1(PPIP32 "%s: %d PWord%s left in FIFO\n",
1581 			  p->name, residue,
1582 			  (residue == 1) ? " was" : "s were");
1583 
1584 	/* Now reset the FIFO */
1585 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1586 
1587 	/* Host recovery for ECP mode */
1588 	if (mode == ECR_MODE_ECP) {
1589 		parport_ip32_data_reverse(p);
1590 		parport_ip32_frob_control(p, DCR_nINIT, 0);
1591 		if (parport_wait_peripheral(p, DSR_PERROR, 0))
1592 			pr_debug1(PPIP32 "%s: PEerror timeout 1 in %s\n",
1593 				  p->name, __func__);
1594 		parport_ip32_frob_control(p, DCR_STROBE, DCR_STROBE);
1595 		parport_ip32_frob_control(p, DCR_nINIT, DCR_nINIT);
1596 		if (parport_wait_peripheral(p, DSR_PERROR, DSR_PERROR))
1597 			pr_debug1(PPIP32 "%s: PEerror timeout 2 in %s\n",
1598 				  p->name, __func__);
1599 	}
1600 
1601 	/* Adjust residue if needed */
1602 	parport_ip32_set_mode(p, ECR_MODE_CFG);
1603 	cnfga = readb(priv->regs.cnfgA);
1604 	if (!(cnfga & CNFGA_nBYTEINTRANS)) {
1605 		pr_debug1(PPIP32 "%s: cnfgA contains 0x%02x\n",
1606 			  p->name, cnfga);
1607 		pr_debug1(PPIP32 "%s: Accounting for extra byte\n",
1608 			  p->name);
1609 		residue++;
1610 	}
1611 
1612 	/* Don't care about partial PWords since we do not support
1613 	 * PWord != 1 byte. */
1614 
1615 	/* Back to forward PS2 mode. */
1616 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1617 	parport_ip32_data_forward(p);
1618 
1619 	return residue;
1620 }
1621 
1622 /**
1623  * parport_ip32_compat_write_data - write a block of data in SPP mode
1624  * @p:		pointer to &struct parport
1625  * @buf:	buffer of data to write
1626  * @len:	length of buffer @buf
1627  * @flags:	ignored
1628  */
1629 static size_t parport_ip32_compat_write_data(struct parport *p,
1630 					     const void *buf, size_t len,
1631 					     int flags)
1632 {
1633 	static unsigned int ready_before = 1;
1634 	struct parport_ip32_private * const priv = p->physport->private_data;
1635 	struct parport * const physport = p->physport;
1636 	size_t written = 0;
1637 
1638 	/* Special case: a timeout of zero means we cannot call schedule().
1639 	 * Also if O_NONBLOCK is set then use the default implementation. */
1640 	if (physport->cad->timeout <= PARPORT_INACTIVITY_O_NONBLOCK)
1641 		return parport_ieee1284_write_compat(p, buf, len, flags);
1642 
1643 	/* Reset FIFO, go in forward mode, and disable ackIntEn */
1644 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1645 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
1646 	parport_ip32_data_forward(p);
1647 	parport_ip32_disable_irq(p);
1648 	parport_ip32_set_mode(p, ECR_MODE_PPF);
1649 	physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;
1650 
1651 	/* Wait for peripheral to become ready */
1652 	if (parport_wait_peripheral(p, DSR_nBUSY | DSR_nFAULT,
1653 				       DSR_nBUSY | DSR_nFAULT)) {
1654 		/* Avoid to flood the logs */
1655 		if (ready_before)
1656 			printk(KERN_INFO PPIP32 "%s: not ready in %s\n",
1657 			       p->name, __func__);
1658 		ready_before = 0;
1659 		goto stop;
1660 	}
1661 	ready_before = 1;
1662 
1663 	written = parport_ip32_fifo_write_block(p, buf, len);
1664 
1665 	/* Wait FIFO to empty.  Timeout is proportional to FIFO_depth.  */
1666 	parport_ip32_drain_fifo(p, physport->cad->timeout * priv->fifo_depth);
1667 
1668 	/* Check for a potential residue */
1669 	written -= parport_ip32_get_fifo_residue(p, ECR_MODE_PPF);
1670 
1671 	/* Then, wait for BUSY to get low. */
1672 	if (parport_wait_peripheral(p, DSR_nBUSY, DSR_nBUSY))
1673 		printk(KERN_DEBUG PPIP32 "%s: BUSY timeout in %s\n",
1674 		       p->name, __func__);
1675 
1676 stop:
1677 	/* Reset FIFO */
1678 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1679 	physport->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
1680 
1681 	return written;
1682 }
1683 
1684 /*
1685  * FIXME - Insert here parport_ip32_ecp_read_data().
1686  */
1687 
1688 /**
1689  * parport_ip32_ecp_write_data - write a block of data in ECP mode
1690  * @p:		pointer to &struct parport
1691  * @buf:	buffer of data to write
1692  * @len:	length of buffer @buf
1693  * @flags:	ignored
1694  */
1695 static size_t parport_ip32_ecp_write_data(struct parport *p,
1696 					  const void *buf, size_t len,
1697 					  int flags)
1698 {
1699 	static unsigned int ready_before = 1;
1700 	struct parport_ip32_private * const priv = p->physport->private_data;
1701 	struct parport * const physport = p->physport;
1702 	size_t written = 0;
1703 
1704 	/* Special case: a timeout of zero means we cannot call schedule().
1705 	 * Also if O_NONBLOCK is set then use the default implementation. */
1706 	if (physport->cad->timeout <= PARPORT_INACTIVITY_O_NONBLOCK)
1707 		return parport_ieee1284_ecp_write_data(p, buf, len, flags);
1708 
1709 	/* Negotiate to forward mode if necessary. */
1710 	if (physport->ieee1284.phase != IEEE1284_PH_FWD_IDLE) {
1711 		/* Event 47: Set nInit high. */
1712 		parport_ip32_frob_control(p, DCR_nINIT | DCR_AUTOFD,
1713 					     DCR_nINIT | DCR_AUTOFD);
1714 
1715 		/* Event 49: PError goes high. */
1716 		if (parport_wait_peripheral(p, DSR_PERROR, DSR_PERROR)) {
1717 			printk(KERN_DEBUG PPIP32 "%s: PError timeout in %s",
1718 			       p->name, __func__);
1719 			physport->ieee1284.phase = IEEE1284_PH_ECP_DIR_UNKNOWN;
1720 			return 0;
1721 		}
1722 	}
1723 
1724 	/* Reset FIFO, go in forward mode, and disable ackIntEn */
1725 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1726 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
1727 	parport_ip32_data_forward(p);
1728 	parport_ip32_disable_irq(p);
1729 	parport_ip32_set_mode(p, ECR_MODE_ECP);
1730 	physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;
1731 
1732 	/* Wait for peripheral to become ready */
1733 	if (parport_wait_peripheral(p, DSR_nBUSY | DSR_nFAULT,
1734 				       DSR_nBUSY | DSR_nFAULT)) {
1735 		/* Avoid to flood the logs */
1736 		if (ready_before)
1737 			printk(KERN_INFO PPIP32 "%s: not ready in %s\n",
1738 			       p->name, __func__);
1739 		ready_before = 0;
1740 		goto stop;
1741 	}
1742 	ready_before = 1;
1743 
1744 	written = parport_ip32_fifo_write_block(p, buf, len);
1745 
1746 	/* Wait FIFO to empty.  Timeout is proportional to FIFO_depth.  */
1747 	parport_ip32_drain_fifo(p, physport->cad->timeout * priv->fifo_depth);
1748 
1749 	/* Check for a potential residue */
1750 	written -= parport_ip32_get_fifo_residue(p, ECR_MODE_ECP);
1751 
1752 	/* Then, wait for BUSY to get low. */
1753 	if (parport_wait_peripheral(p, DSR_nBUSY, DSR_nBUSY))
1754 		printk(KERN_DEBUG PPIP32 "%s: BUSY timeout in %s\n",
1755 		       p->name, __func__);
1756 
1757 stop:
1758 	/* Reset FIFO */
1759 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1760 	physport->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
1761 
1762 	return written;
1763 }
1764 
1765 /*
1766  * FIXME - Insert here parport_ip32_ecp_write_addr().
1767  */
1768 
1769 /*--- Default parport operations ---------------------------------------*/
1770 
1771 static __initdata struct parport_operations parport_ip32_ops = {
1772 	.write_data		= parport_ip32_write_data,
1773 	.read_data		= parport_ip32_read_data,
1774 
1775 	.write_control		= parport_ip32_write_control,
1776 	.read_control		= parport_ip32_read_control,
1777 	.frob_control		= parport_ip32_frob_control,
1778 
1779 	.read_status		= parport_ip32_read_status,
1780 
1781 	.enable_irq		= parport_ip32_enable_irq,
1782 	.disable_irq		= parport_ip32_disable_irq,
1783 
1784 	.data_forward		= parport_ip32_data_forward,
1785 	.data_reverse		= parport_ip32_data_reverse,
1786 
1787 	.init_state		= parport_ip32_init_state,
1788 	.save_state		= parport_ip32_save_state,
1789 	.restore_state		= parport_ip32_restore_state,
1790 
1791 	.epp_write_data		= parport_ieee1284_epp_write_data,
1792 	.epp_read_data		= parport_ieee1284_epp_read_data,
1793 	.epp_write_addr		= parport_ieee1284_epp_write_addr,
1794 	.epp_read_addr		= parport_ieee1284_epp_read_addr,
1795 
1796 	.ecp_write_data		= parport_ieee1284_ecp_write_data,
1797 	.ecp_read_data		= parport_ieee1284_ecp_read_data,
1798 	.ecp_write_addr		= parport_ieee1284_ecp_write_addr,
1799 
1800 	.compat_write_data	= parport_ieee1284_write_compat,
1801 	.nibble_read_data	= parport_ieee1284_read_nibble,
1802 	.byte_read_data		= parport_ieee1284_read_byte,
1803 
1804 	.owner			= THIS_MODULE,
1805 };
1806 
1807 /*--- Device detection -------------------------------------------------*/
1808 
1809 /**
1810  * parport_ip32_ecp_supported - check for an ECP port
1811  * @p:		pointer to the &parport structure
1812  *
1813  * Returns 1 if an ECP port is found, and 0 otherwise.  This function actually
1814  * checks if an Extended Control Register seems to be present.  On successful
1815  * return, the port is placed in SPP mode.
1816  */
1817 static __init unsigned int parport_ip32_ecp_supported(struct parport *p)
1818 {
1819 	struct parport_ip32_private * const priv = p->physport->private_data;
1820 	unsigned int ecr;
1821 
1822 	ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
1823 	writeb(ecr, priv->regs.ecr);
1824 	if (readb(priv->regs.ecr) != (ecr | ECR_F_EMPTY))
1825 		goto fail;
1826 
1827 	pr_probe(p, "Found working ECR register\n");
1828 	parport_ip32_set_mode(p, ECR_MODE_SPP);
1829 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
1830 	return 1;
1831 
1832 fail:
1833 	pr_probe(p, "ECR register not found\n");
1834 	return 0;
1835 }
1836 
1837 /**
1838  * parport_ip32_fifo_supported - check for FIFO parameters
1839  * @p:		pointer to the &parport structure
1840  *
1841  * Check for FIFO parameters of an Extended Capabilities Port.  Returns 1 on
1842  * success, and 0 otherwise.  Adjust FIFO parameters in the parport structure.
1843  * On return, the port is placed in SPP mode.
1844  */
1845 static __init unsigned int parport_ip32_fifo_supported(struct parport *p)
1846 {
1847 	struct parport_ip32_private * const priv = p->physport->private_data;
1848 	unsigned int configa, configb;
1849 	unsigned int pword;
1850 	unsigned int i;
1851 
1852 	/* Configuration mode */
1853 	parport_ip32_set_mode(p, ECR_MODE_CFG);
1854 	configa = readb(priv->regs.cnfgA);
1855 	configb = readb(priv->regs.cnfgB);
1856 
1857 	/* Find out PWord size */
1858 	switch (configa & CNFGA_ID_MASK) {
1859 	case CNFGA_ID_8:
1860 		pword = 1;
1861 		break;
1862 	case CNFGA_ID_16:
1863 		pword = 2;
1864 		break;
1865 	case CNFGA_ID_32:
1866 		pword = 4;
1867 		break;
1868 	default:
1869 		pr_probe(p, "Unknown implementation ID: 0x%0x\n",
1870 			 (configa & CNFGA_ID_MASK) >> CNFGA_ID_SHIFT);
1871 		goto fail;
1872 		break;
1873 	}
1874 	if (pword != 1) {
1875 		pr_probe(p, "Unsupported PWord size: %u\n", pword);
1876 		goto fail;
1877 	}
1878 	priv->pword = pword;
1879 	pr_probe(p, "PWord is %u bits\n", 8 * priv->pword);
1880 
1881 	/* Check for compression support */
1882 	writeb(configb | CNFGB_COMPRESS, priv->regs.cnfgB);
1883 	if (readb(priv->regs.cnfgB) & CNFGB_COMPRESS)
1884 		pr_probe(p, "Hardware compression detected (unsupported)\n");
1885 	writeb(configb & ~CNFGB_COMPRESS, priv->regs.cnfgB);
1886 
1887 	/* Reset FIFO and go in test mode (no interrupt, no DMA) */
1888 	parport_ip32_set_mode(p, ECR_MODE_TST);
1889 
1890 	/* FIFO must be empty now */
1891 	if (!(readb(priv->regs.ecr) & ECR_F_EMPTY)) {
1892 		pr_probe(p, "FIFO not reset\n");
1893 		goto fail;
1894 	}
1895 
1896 	/* Find out FIFO depth. */
1897 	priv->fifo_depth = 0;
1898 	for (i = 0; i < 1024; i++) {
1899 		if (readb(priv->regs.ecr) & ECR_F_FULL) {
1900 			/* FIFO full */
1901 			priv->fifo_depth = i;
1902 			break;
1903 		}
1904 		writeb((u8)i, priv->regs.fifo);
1905 	}
1906 	if (i >= 1024) {
1907 		pr_probe(p, "Can't fill FIFO\n");
1908 		goto fail;
1909 	}
1910 	if (!priv->fifo_depth) {
1911 		pr_probe(p, "Can't get FIFO depth\n");
1912 		goto fail;
1913 	}
1914 	pr_probe(p, "FIFO is %u PWords deep\n", priv->fifo_depth);
1915 
1916 	/* Enable interrupts */
1917 	parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
1918 
1919 	/* Find out writeIntrThreshold: number of PWords we know we can write
1920 	 * if we get an interrupt. */
1921 	priv->writeIntrThreshold = 0;
1922 	for (i = 0; i < priv->fifo_depth; i++) {
1923 		if (readb(priv->regs.fifo) != (u8)i) {
1924 			pr_probe(p, "Invalid data in FIFO\n");
1925 			goto fail;
1926 		}
1927 		if (!priv->writeIntrThreshold
1928 		    && readb(priv->regs.ecr) & ECR_SERVINTR)
1929 			/* writeIntrThreshold reached */
1930 			priv->writeIntrThreshold = i + 1;
1931 		if (i + 1 < priv->fifo_depth
1932 		    && readb(priv->regs.ecr) & ECR_F_EMPTY) {
1933 			/* FIFO empty before the last byte? */
1934 			pr_probe(p, "Data lost in FIFO\n");
1935 			goto fail;
1936 		}
1937 	}
1938 	if (!priv->writeIntrThreshold) {
1939 		pr_probe(p, "Can't get writeIntrThreshold\n");
1940 		goto fail;
1941 	}
1942 	pr_probe(p, "writeIntrThreshold is %u\n", priv->writeIntrThreshold);
1943 
1944 	/* FIFO must be empty now */
1945 	if (!(readb(priv->regs.ecr) & ECR_F_EMPTY)) {
1946 		pr_probe(p, "Can't empty FIFO\n");
1947 		goto fail;
1948 	}
1949 
1950 	/* Reset FIFO */
1951 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1952 	/* Set reverse direction (must be in PS2 mode) */
1953 	parport_ip32_data_reverse(p);
1954 	/* Test FIFO, no interrupt, no DMA */
1955 	parport_ip32_set_mode(p, ECR_MODE_TST);
1956 	/* Enable interrupts */
1957 	parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
1958 
1959 	/* Find out readIntrThreshold: number of PWords we can read if we get
1960 	 * an interrupt. */
1961 	priv->readIntrThreshold = 0;
1962 	for (i = 0; i < priv->fifo_depth; i++) {
1963 		writeb(0xaa, priv->regs.fifo);
1964 		if (readb(priv->regs.ecr) & ECR_SERVINTR) {
1965 			/* readIntrThreshold reached */
1966 			priv->readIntrThreshold = i + 1;
1967 			break;
1968 		}
1969 	}
1970 	if (!priv->readIntrThreshold) {
1971 		pr_probe(p, "Can't get readIntrThreshold\n");
1972 		goto fail;
1973 	}
1974 	pr_probe(p, "readIntrThreshold is %u\n", priv->readIntrThreshold);
1975 
1976 	/* Reset ECR */
1977 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1978 	parport_ip32_data_forward(p);
1979 	parport_ip32_set_mode(p, ECR_MODE_SPP);
1980 	return 1;
1981 
1982 fail:
1983 	priv->fifo_depth = 0;
1984 	parport_ip32_set_mode(p, ECR_MODE_SPP);
1985 	return 0;
1986 }
1987 
1988 /*--- Initialization code ----------------------------------------------*/
1989 
1990 /**
1991  * parport_ip32_make_isa_registers - compute (ISA) register addresses
1992  * @regs:	pointer to &struct parport_ip32_regs to fill
1993  * @base:	base address of standard and EPP registers
1994  * @base_hi:	base address of ECP registers
1995  * @regshift:	how much to shift register offset by
1996  *
1997  * Compute register addresses, according to the ISA standard.  The addresses
1998  * of the standard and EPP registers are computed from address @base.  The
1999  * addresses of the ECP registers are computed from address @base_hi.
2000  */
2001 static void __init
2002 parport_ip32_make_isa_registers(struct parport_ip32_regs *regs,
2003 				void __iomem *base, void __iomem *base_hi,
2004 				unsigned int regshift)
2005 {
2006 #define r_base(offset)    ((u8 __iomem *)base    + ((offset) << regshift))
2007 #define r_base_hi(offset) ((u8 __iomem *)base_hi + ((offset) << regshift))
2008 	*regs = (struct parport_ip32_regs){
2009 		.data		= r_base(0),
2010 		.dsr		= r_base(1),
2011 		.dcr		= r_base(2),
2012 		.eppAddr	= r_base(3),
2013 		.eppData0	= r_base(4),
2014 		.eppData1	= r_base(5),
2015 		.eppData2	= r_base(6),
2016 		.eppData3	= r_base(7),
2017 		.ecpAFifo	= r_base(0),
2018 		.fifo		= r_base_hi(0),
2019 		.cnfgA		= r_base_hi(0),
2020 		.cnfgB		= r_base_hi(1),
2021 		.ecr		= r_base_hi(2)
2022 	};
2023 #undef r_base_hi
2024 #undef r_base
2025 }
2026 
2027 /**
2028  * parport_ip32_probe_port - probe and register IP32 built-in parallel port
2029  *
2030  * Returns the new allocated &parport structure.  On error, an error code is
2031  * encoded in return value with the ERR_PTR function.
2032  */
2033 static __init struct parport *parport_ip32_probe_port(void)
2034 {
2035 	struct parport_ip32_regs regs;
2036 	struct parport_ip32_private *priv = NULL;
2037 	struct parport_operations *ops = NULL;
2038 	struct parport *p = NULL;
2039 	int err;
2040 
2041 	parport_ip32_make_isa_registers(&regs, &mace->isa.parallel,
2042 					&mace->isa.ecp1284, 8 /* regshift */);
2043 
2044 	ops = kmalloc(sizeof(struct parport_operations), GFP_KERNEL);
2045 	priv = kmalloc(sizeof(struct parport_ip32_private), GFP_KERNEL);
2046 	p = parport_register_port(0, PARPORT_IRQ_NONE, PARPORT_DMA_NONE, ops);
2047 	if (ops == NULL || priv == NULL || p == NULL) {
2048 		err = -ENOMEM;
2049 		goto fail;
2050 	}
2051 	p->base = MACE_BASE + offsetof(struct sgi_mace, isa.parallel);
2052 	p->base_hi = MACE_BASE + offsetof(struct sgi_mace, isa.ecp1284);
2053 	p->private_data = priv;
2054 
2055 	*ops = parport_ip32_ops;
2056 	*priv = (struct parport_ip32_private){
2057 		.regs			= regs,
2058 		.dcr_writable		= DCR_DIR | DCR_SELECT | DCR_nINIT |
2059 					  DCR_AUTOFD | DCR_STROBE,
2060 		.irq_mode		= PARPORT_IP32_IRQ_FWD,
2061 	};
2062 	init_completion(&priv->irq_complete);
2063 
2064 	/* Probe port. */
2065 	if (!parport_ip32_ecp_supported(p)) {
2066 		err = -ENODEV;
2067 		goto fail;
2068 	}
2069 	parport_ip32_dump_state(p, "begin init", 0);
2070 
2071 	/* We found what looks like a working ECR register.  Simply assume
2072 	 * that all modes are correctly supported.  Enable basic modes. */
2073 	p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
2074 	p->modes |= PARPORT_MODE_TRISTATE;
2075 
2076 	if (!parport_ip32_fifo_supported(p)) {
2077 		printk(KERN_WARNING PPIP32
2078 		       "%s: error: FIFO disabled\n", p->name);
2079 		/* Disable hardware modes depending on a working FIFO. */
2080 		features &= ~PARPORT_IP32_ENABLE_SPP;
2081 		features &= ~PARPORT_IP32_ENABLE_ECP;
2082 		/* DMA is not needed if FIFO is not supported.  */
2083 		features &= ~PARPORT_IP32_ENABLE_DMA;
2084 	}
2085 
2086 	/* Request IRQ */
2087 	if (features & PARPORT_IP32_ENABLE_IRQ) {
2088 		int irq = MACEISA_PARALLEL_IRQ;
2089 		if (request_irq(irq, parport_ip32_interrupt, 0, p->name, p)) {
2090 			printk(KERN_WARNING PPIP32
2091 			       "%s: error: IRQ disabled\n", p->name);
2092 			/* DMA cannot work without interrupts. */
2093 			features &= ~PARPORT_IP32_ENABLE_DMA;
2094 		} else {
2095 			pr_probe(p, "Interrupt support enabled\n");
2096 			p->irq = irq;
2097 			priv->dcr_writable |= DCR_IRQ;
2098 		}
2099 	}
2100 
2101 	/* Allocate DMA resources */
2102 	if (features & PARPORT_IP32_ENABLE_DMA) {
2103 		if (parport_ip32_dma_register())
2104 			printk(KERN_WARNING PPIP32
2105 			       "%s: error: DMA disabled\n", p->name);
2106 		else {
2107 			pr_probe(p, "DMA support enabled\n");
2108 			p->dma = 0; /* arbitrary value != PARPORT_DMA_NONE */
2109 			p->modes |= PARPORT_MODE_DMA;
2110 		}
2111 	}
2112 
2113 	if (features & PARPORT_IP32_ENABLE_SPP) {
2114 		/* Enable compatibility FIFO mode */
2115 		p->ops->compat_write_data = parport_ip32_compat_write_data;
2116 		p->modes |= PARPORT_MODE_COMPAT;
2117 		pr_probe(p, "Hardware support for SPP mode enabled\n");
2118 	}
2119 	if (features & PARPORT_IP32_ENABLE_EPP) {
2120 		/* Set up access functions to use EPP hardware. */
2121 		p->ops->epp_read_data = parport_ip32_epp_read_data;
2122 		p->ops->epp_write_data = parport_ip32_epp_write_data;
2123 		p->ops->epp_read_addr = parport_ip32_epp_read_addr;
2124 		p->ops->epp_write_addr = parport_ip32_epp_write_addr;
2125 		p->modes |= PARPORT_MODE_EPP;
2126 		pr_probe(p, "Hardware support for EPP mode enabled\n");
2127 	}
2128 	if (features & PARPORT_IP32_ENABLE_ECP) {
2129 		/* Enable ECP FIFO mode */
2130 		p->ops->ecp_write_data = parport_ip32_ecp_write_data;
2131 		/* FIXME - not implemented */
2132 /*		p->ops->ecp_read_data  = parport_ip32_ecp_read_data; */
2133 /*		p->ops->ecp_write_addr = parport_ip32_ecp_write_addr; */
2134 		p->modes |= PARPORT_MODE_ECP;
2135 		pr_probe(p, "Hardware support for ECP mode enabled\n");
2136 	}
2137 
2138 	/* Initialize the port with sensible values */
2139 	parport_ip32_set_mode(p, ECR_MODE_PS2);
2140 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
2141 	parport_ip32_data_forward(p);
2142 	parport_ip32_disable_irq(p);
2143 	parport_ip32_write_data(p, 0x00);
2144 	parport_ip32_dump_state(p, "end init", 0);
2145 
2146 	/* Print out what we found */
2147 	printk(KERN_INFO "%s: SGI IP32 at 0x%lx (0x%lx)",
2148 	       p->name, p->base, p->base_hi);
2149 	if (p->irq != PARPORT_IRQ_NONE)
2150 		printk(", irq %d", p->irq);
2151 	printk(" [");
2152 #define printmode(x)	if (p->modes & PARPORT_MODE_##x)		\
2153 				printk("%s%s", f++ ? "," : "", #x)
2154 	{
2155 		unsigned int f = 0;
2156 		printmode(PCSPP);
2157 		printmode(TRISTATE);
2158 		printmode(COMPAT);
2159 		printmode(EPP);
2160 		printmode(ECP);
2161 		printmode(DMA);
2162 	}
2163 #undef printmode
2164 	printk("]\n");
2165 
2166 	parport_announce_port(p);
2167 	return p;
2168 
2169 fail:
2170 	if (p)
2171 		parport_put_port(p);
2172 	kfree(priv);
2173 	kfree(ops);
2174 	return ERR_PTR(err);
2175 }
2176 
2177 /**
2178  * parport_ip32_unregister_port - unregister a parallel port
2179  * @p:		pointer to the &struct parport
2180  *
2181  * Unregisters a parallel port and free previously allocated resources
2182  * (memory, IRQ, ...).
2183  */
2184 static __exit void parport_ip32_unregister_port(struct parport *p)
2185 {
2186 	struct parport_ip32_private * const priv = p->physport->private_data;
2187 	struct parport_operations *ops = p->ops;
2188 
2189 	parport_remove_port(p);
2190 	if (p->modes & PARPORT_MODE_DMA)
2191 		parport_ip32_dma_unregister();
2192 	if (p->irq != PARPORT_IRQ_NONE)
2193 		free_irq(p->irq, p);
2194 	parport_put_port(p);
2195 	kfree(priv);
2196 	kfree(ops);
2197 }
2198 
2199 /**
2200  * parport_ip32_init - module initialization function
2201  */
2202 static int __init parport_ip32_init(void)
2203 {
2204 	pr_info(PPIP32 "SGI IP32 built-in parallel port driver v0.6\n");
2205 	pr_debug1(PPIP32 "Compiled on %s, %s\n", __DATE__, __TIME__);
2206 	this_port = parport_ip32_probe_port();
2207 	return IS_ERR(this_port) ? PTR_ERR(this_port) : 0;
2208 }
2209 
2210 /**
2211  * parport_ip32_exit - module termination function
2212  */
2213 static void __exit parport_ip32_exit(void)
2214 {
2215 	parport_ip32_unregister_port(this_port);
2216 }
2217 
2218 /*--- Module stuff -----------------------------------------------------*/
2219 
2220 MODULE_AUTHOR("Arnaud Giersch <arnaud.giersch@free.fr>");
2221 MODULE_DESCRIPTION("SGI IP32 built-in parallel port driver");
2222 MODULE_LICENSE("GPL");
2223 MODULE_VERSION("0.6");		/* update in parport_ip32_init() too */
2224 
2225 module_init(parport_ip32_init);
2226 module_exit(parport_ip32_exit);
2227 
2228 module_param(verbose_probing, bool, S_IRUGO);
2229 MODULE_PARM_DESC(verbose_probing, "Log chit-chat during initialization");
2230 
2231 module_param(features, uint, S_IRUGO);
2232 MODULE_PARM_DESC(features,
2233 		 "Bit mask of features to enable"
2234 		 ", bit 0: IRQ support"
2235 		 ", bit 1: DMA support"
2236 		 ", bit 2: hardware SPP mode"
2237 		 ", bit 3: hardware EPP mode"
2238 		 ", bit 4: hardware ECP mode");
2239 
2240 /*--- Inform (X)Emacs about preferred coding style ---------------------*/
2241 /*
2242  * Local Variables:
2243  * mode: c
2244  * c-file-style: "linux"
2245  * indent-tabs-mode: t
2246  * tab-width: 8
2247  * fill-column: 78
2248  * ispell-local-dictionary: "american"
2249  * End:
2250  */
2251