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/signal.h>
106 #include <linux/slab.h>
107 #include <linux/spinlock.h>
108 #include <linux/stddef.h>
109 #include <linux/types.h>
110 #include <asm/io.h>
111 #include <asm/ip32/ip32_ints.h>
112 #include <asm/ip32/mace.h>
113 
114 /*--- Global variables -------------------------------------------------*/
115 
116 /* Verbose probing on by default for debugging. */
117 #if DEBUG_PARPORT_IP32 >= 1
118 #	define DEFAULT_VERBOSE_PROBING	1
119 #else
120 #	define DEFAULT_VERBOSE_PROBING	0
121 #endif
122 
123 /* Default prefix for printk */
124 #define PPIP32 "parport_ip32: "
125 
126 /*
127  * These are the module parameters:
128  * @features:		bit mask of features to enable/disable
129  *			(all enabled by default)
130  * @verbose_probing:	log chit-chat during initialization
131  */
132 #define PARPORT_IP32_ENABLE_IRQ	(1U << 0)
133 #define PARPORT_IP32_ENABLE_DMA	(1U << 1)
134 #define PARPORT_IP32_ENABLE_SPP	(1U << 2)
135 #define PARPORT_IP32_ENABLE_EPP	(1U << 3)
136 #define PARPORT_IP32_ENABLE_ECP	(1U << 4)
137 static unsigned int features =	~0U;
138 static bool verbose_probing =	DEFAULT_VERBOSE_PROBING;
139 
140 /* We do not support more than one port. */
141 static struct parport *this_port;
142 
143 /* Timing constants for FIFO modes.  */
144 #define FIFO_NFAULT_TIMEOUT	100	/* milliseconds */
145 #define FIFO_POLLING_INTERVAL	50	/* microseconds */
146 
147 /*--- I/O register definitions -----------------------------------------*/
148 
149 /**
150  * struct parport_ip32_regs - virtual addresses of parallel port registers
151  * @data:	Data Register
152  * @dsr:	Device Status Register
153  * @dcr:	Device Control Register
154  * @eppAddr:	EPP Address Register
155  * @eppData0:	EPP Data Register 0
156  * @eppData1:	EPP Data Register 1
157  * @eppData2:	EPP Data Register 2
158  * @eppData3:	EPP Data Register 3
159  * @ecpAFifo:	ECP Address FIFO
160  * @fifo:	General FIFO register.  The same address is used for:
161  *		- cFifo, the Parallel Port DATA FIFO
162  *		- ecpDFifo, the ECP Data FIFO
163  *		- tFifo, the ECP Test FIFO
164  * @cnfgA:	Configuration Register A
165  * @cnfgB:	Configuration Register B
166  * @ecr:	Extended Control Register
167  */
168 struct parport_ip32_regs {
169 	void __iomem *data;
170 	void __iomem *dsr;
171 	void __iomem *dcr;
172 	void __iomem *eppAddr;
173 	void __iomem *eppData0;
174 	void __iomem *eppData1;
175 	void __iomem *eppData2;
176 	void __iomem *eppData3;
177 	void __iomem *ecpAFifo;
178 	void __iomem *fifo;
179 	void __iomem *cnfgA;
180 	void __iomem *cnfgB;
181 	void __iomem *ecr;
182 };
183 
184 /* Device Status Register */
185 #define DSR_nBUSY		(1U << 7)	/* PARPORT_STATUS_BUSY */
186 #define DSR_nACK		(1U << 6)	/* PARPORT_STATUS_ACK */
187 #define DSR_PERROR		(1U << 5)	/* PARPORT_STATUS_PAPEROUT */
188 #define DSR_SELECT		(1U << 4)	/* PARPORT_STATUS_SELECT */
189 #define DSR_nFAULT		(1U << 3)	/* PARPORT_STATUS_ERROR */
190 #define DSR_nPRINT		(1U << 2)	/* specific to TL16PIR552 */
191 /* #define DSR_reserved		(1U << 1) */
192 #define DSR_TIMEOUT		(1U << 0)	/* EPP timeout */
193 
194 /* Device Control Register */
195 /* #define DCR_reserved		(1U << 7) | (1U <<  6) */
196 #define DCR_DIR			(1U << 5)	/* direction */
197 #define DCR_IRQ			(1U << 4)	/* interrupt on nAck */
198 #define DCR_SELECT		(1U << 3)	/* PARPORT_CONTROL_SELECT */
199 #define DCR_nINIT		(1U << 2)	/* PARPORT_CONTROL_INIT */
200 #define DCR_AUTOFD		(1U << 1)	/* PARPORT_CONTROL_AUTOFD */
201 #define DCR_STROBE		(1U << 0)	/* PARPORT_CONTROL_STROBE */
202 
203 /* ECP Configuration Register A */
204 #define CNFGA_IRQ		(1U << 7)
205 #define CNFGA_ID_MASK		((1U << 6) | (1U << 5) | (1U << 4))
206 #define CNFGA_ID_SHIFT		4
207 #define CNFGA_ID_16		(00U << CNFGA_ID_SHIFT)
208 #define CNFGA_ID_8		(01U << CNFGA_ID_SHIFT)
209 #define CNFGA_ID_32		(02U << CNFGA_ID_SHIFT)
210 /* #define CNFGA_reserved	(1U << 3) */
211 #define CNFGA_nBYTEINTRANS	(1U << 2)
212 #define CNFGA_PWORDLEFT		((1U << 1) | (1U << 0))
213 
214 /* ECP Configuration Register B */
215 #define CNFGB_COMPRESS		(1U << 7)
216 #define CNFGB_INTRVAL		(1U << 6)
217 #define CNFGB_IRQ_MASK		((1U << 5) | (1U << 4) | (1U << 3))
218 #define CNFGB_IRQ_SHIFT		3
219 #define CNFGB_DMA_MASK		((1U << 2) | (1U << 1) | (1U << 0))
220 #define CNFGB_DMA_SHIFT		0
221 
222 /* Extended Control Register */
223 #define ECR_MODE_MASK		((1U << 7) | (1U << 6) | (1U << 5))
224 #define ECR_MODE_SHIFT		5
225 #define ECR_MODE_SPP		(00U << ECR_MODE_SHIFT)
226 #define ECR_MODE_PS2		(01U << ECR_MODE_SHIFT)
227 #define ECR_MODE_PPF		(02U << ECR_MODE_SHIFT)
228 #define ECR_MODE_ECP		(03U << ECR_MODE_SHIFT)
229 #define ECR_MODE_EPP		(04U << ECR_MODE_SHIFT)
230 /* #define ECR_MODE_reserved	(05U << ECR_MODE_SHIFT) */
231 #define ECR_MODE_TST		(06U << ECR_MODE_SHIFT)
232 #define ECR_MODE_CFG		(07U << ECR_MODE_SHIFT)
233 #define ECR_nERRINTR		(1U << 4)
234 #define ECR_DMAEN		(1U << 3)
235 #define ECR_SERVINTR		(1U << 2)
236 #define ECR_F_FULL		(1U << 1)
237 #define ECR_F_EMPTY		(1U << 0)
238 
239 /*--- Private data -----------------------------------------------------*/
240 
241 /**
242  * enum parport_ip32_irq_mode - operation mode of interrupt handler
243  * @PARPORT_IP32_IRQ_FWD:	forward interrupt to the upper parport layer
244  * @PARPORT_IP32_IRQ_HERE:	interrupt is handled locally
245  */
246 enum parport_ip32_irq_mode { PARPORT_IP32_IRQ_FWD, PARPORT_IP32_IRQ_HERE };
247 
248 /**
249  * struct parport_ip32_private - private stuff for &struct parport
250  * @regs:		register addresses
251  * @dcr_cache:		cached contents of DCR
252  * @dcr_writable:	bit mask of writable DCR bits
253  * @pword:		number of bytes per PWord
254  * @fifo_depth:		number of PWords that FIFO will hold
255  * @readIntrThreshold:	minimum number of PWords we can read
256  *			if we get an interrupt
257  * @writeIntrThreshold:	minimum number of PWords we can write
258  *			if we get an interrupt
259  * @irq_mode:		operation mode of interrupt handler for this port
260  * @irq_complete:	mutex used to wait for an interrupt to occur
261  */
262 struct parport_ip32_private {
263 	struct parport_ip32_regs	regs;
264 	unsigned int			dcr_cache;
265 	unsigned int			dcr_writable;
266 	unsigned int			pword;
267 	unsigned int			fifo_depth;
268 	unsigned int			readIntrThreshold;
269 	unsigned int			writeIntrThreshold;
270 	enum parport_ip32_irq_mode	irq_mode;
271 	struct completion		irq_complete;
272 };
273 
274 /*--- Debug code -------------------------------------------------------*/
275 
276 /*
277  * pr_debug1 - print debug messages
278  *
279  * This is like pr_debug(), but is defined for %DEBUG_PARPORT_IP32 >= 1
280  */
281 #if DEBUG_PARPORT_IP32 >= 1
282 #	define pr_debug1(...)	printk(KERN_DEBUG __VA_ARGS__)
283 #else /* DEBUG_PARPORT_IP32 < 1 */
284 #	define pr_debug1(...)	do { } while (0)
285 #endif
286 
287 /*
288  * pr_trace, pr_trace1 - trace function calls
289  * @p:		pointer to &struct parport
290  * @fmt:	printk format string
291  * @...:	parameters for format string
292  *
293  * Macros used to trace function calls.  The given string is formatted after
294  * function name.  pr_trace() uses pr_debug(), and pr_trace1() uses
295  * pr_debug1().  __pr_trace() is the low-level macro and is not to be used
296  * directly.
297  */
298 #define __pr_trace(pr, p, fmt, ...)					\
299 	pr("%s: %s" fmt "\n",						\
300 	   ({ const struct parport *__p = (p);				\
301 		   __p ? __p->name : "parport_ip32"; }),		\
302 	   __func__ , ##__VA_ARGS__)
303 #define pr_trace(p, fmt, ...)	__pr_trace(pr_debug, p, fmt , ##__VA_ARGS__)
304 #define pr_trace1(p, fmt, ...)	__pr_trace(pr_debug1, p, fmt , ##__VA_ARGS__)
305 
306 /*
307  * __pr_probe, pr_probe - print message if @verbose_probing is true
308  * @p:		pointer to &struct parport
309  * @fmt:	printk format string
310  * @...:	parameters for format string
311  *
312  * For new lines, use pr_probe().  Use __pr_probe() for continued lines.
313  */
314 #define __pr_probe(...)							\
315 	do { if (verbose_probing) printk(__VA_ARGS__); } while (0)
316 #define pr_probe(p, fmt, ...)						\
317 	__pr_probe(KERN_INFO PPIP32 "0x%lx: " fmt, (p)->base , ##__VA_ARGS__)
318 
319 /*
320  * parport_ip32_dump_state - print register status of parport
321  * @p:		pointer to &struct parport
322  * @str:	string to add in message
323  * @show_ecp_config:	shall we dump ECP configuration registers too?
324  *
325  * This function is only here for debugging purpose, and should be used with
326  * care.  Reading the parallel port registers may have undesired side effects.
327  * Especially if @show_ecp_config is true, the parallel port is resetted.
328  * This function is only defined if %DEBUG_PARPORT_IP32 >= 2.
329  */
330 #if DEBUG_PARPORT_IP32 >= 2
331 static void parport_ip32_dump_state(struct parport *p, char *str,
332 				    unsigned int show_ecp_config)
333 {
334 	struct parport_ip32_private * const priv = p->physport->private_data;
335 	unsigned int i;
336 
337 	printk(KERN_DEBUG PPIP32 "%s: state (%s):\n", p->name, str);
338 	{
339 		static const char ecr_modes[8][4] = {"SPP", "PS2", "PPF",
340 						     "ECP", "EPP", "???",
341 						     "TST", "CFG"};
342 		unsigned int ecr = readb(priv->regs.ecr);
343 		printk(KERN_DEBUG PPIP32 "    ecr=0x%02x", ecr);
344 		printk(" %s",
345 		       ecr_modes[(ecr & ECR_MODE_MASK) >> ECR_MODE_SHIFT]);
346 		if (ecr & ECR_nERRINTR)
347 			printk(",nErrIntrEn");
348 		if (ecr & ECR_DMAEN)
349 			printk(",dmaEn");
350 		if (ecr & ECR_SERVINTR)
351 			printk(",serviceIntr");
352 		if (ecr & ECR_F_FULL)
353 			printk(",f_full");
354 		if (ecr & ECR_F_EMPTY)
355 			printk(",f_empty");
356 		printk("\n");
357 	}
358 	if (show_ecp_config) {
359 		unsigned int oecr, cnfgA, cnfgB;
360 		oecr = readb(priv->regs.ecr);
361 		writeb(ECR_MODE_PS2, priv->regs.ecr);
362 		writeb(ECR_MODE_CFG, priv->regs.ecr);
363 		cnfgA = readb(priv->regs.cnfgA);
364 		cnfgB = readb(priv->regs.cnfgB);
365 		writeb(ECR_MODE_PS2, priv->regs.ecr);
366 		writeb(oecr, priv->regs.ecr);
367 		printk(KERN_DEBUG PPIP32 "    cnfgA=0x%02x", cnfgA);
368 		printk(" ISA-%s", (cnfgA & CNFGA_IRQ) ? "Level" : "Pulses");
369 		switch (cnfgA & CNFGA_ID_MASK) {
370 		case CNFGA_ID_8:
371 			printk(",8 bits");
372 			break;
373 		case CNFGA_ID_16:
374 			printk(",16 bits");
375 			break;
376 		case CNFGA_ID_32:
377 			printk(",32 bits");
378 			break;
379 		default:
380 			printk(",unknown ID");
381 			break;
382 		}
383 		if (!(cnfgA & CNFGA_nBYTEINTRANS))
384 			printk(",ByteInTrans");
385 		if ((cnfgA & CNFGA_ID_MASK) != CNFGA_ID_8)
386 			printk(",%d byte%s left", cnfgA & CNFGA_PWORDLEFT,
387 			       ((cnfgA & CNFGA_PWORDLEFT) > 1) ? "s" : "");
388 		printk("\n");
389 		printk(KERN_DEBUG PPIP32 "    cnfgB=0x%02x", cnfgB);
390 		printk(" irq=%u,dma=%u",
391 		       (cnfgB & CNFGB_IRQ_MASK) >> CNFGB_IRQ_SHIFT,
392 		       (cnfgB & CNFGB_DMA_MASK) >> CNFGB_DMA_SHIFT);
393 		printk(",intrValue=%d", !!(cnfgB & CNFGB_INTRVAL));
394 		if (cnfgB & CNFGB_COMPRESS)
395 			printk(",compress");
396 		printk("\n");
397 	}
398 	for (i = 0; i < 2; i++) {
399 		unsigned int dcr = i ? priv->dcr_cache : readb(priv->regs.dcr);
400 		printk(KERN_DEBUG PPIP32 "    dcr(%s)=0x%02x",
401 		       i ? "soft" : "hard", dcr);
402 		printk(" %s", (dcr & DCR_DIR) ? "rev" : "fwd");
403 		if (dcr & DCR_IRQ)
404 			printk(",ackIntEn");
405 		if (!(dcr & DCR_SELECT))
406 			printk(",nSelectIn");
407 		if (dcr & DCR_nINIT)
408 			printk(",nInit");
409 		if (!(dcr & DCR_AUTOFD))
410 			printk(",nAutoFD");
411 		if (!(dcr & DCR_STROBE))
412 			printk(",nStrobe");
413 		printk("\n");
414 	}
415 #define sep (f++ ? ',' : ' ')
416 	{
417 		unsigned int f = 0;
418 		unsigned int dsr = readb(priv->regs.dsr);
419 		printk(KERN_DEBUG PPIP32 "    dsr=0x%02x", dsr);
420 		if (!(dsr & DSR_nBUSY))
421 			printk("%cBusy", sep);
422 		if (dsr & DSR_nACK)
423 			printk("%cnAck", sep);
424 		if (dsr & DSR_PERROR)
425 			printk("%cPError", sep);
426 		if (dsr & DSR_SELECT)
427 			printk("%cSelect", sep);
428 		if (dsr & DSR_nFAULT)
429 			printk("%cnFault", sep);
430 		if (!(dsr & DSR_nPRINT))
431 			printk("%c(Print)", sep);
432 		if (dsr & DSR_TIMEOUT)
433 			printk("%cTimeout", sep);
434 		printk("\n");
435 	}
436 #undef sep
437 }
438 #else /* DEBUG_PARPORT_IP32 < 2 */
439 #define parport_ip32_dump_state(...)	do { } while (0)
440 #endif
441 
442 /*
443  * CHECK_EXTRA_BITS - track and log extra bits
444  * @p:		pointer to &struct parport
445  * @b:		byte to inspect
446  * @m:		bit mask of authorized bits
447  *
448  * This is used to track and log extra bits that should not be there in
449  * parport_ip32_write_control() and parport_ip32_frob_control().  It is only
450  * defined if %DEBUG_PARPORT_IP32 >= 1.
451  */
452 #if DEBUG_PARPORT_IP32 >= 1
453 #define CHECK_EXTRA_BITS(p, b, m)					\
454 	do {								\
455 		unsigned int __b = (b), __m = (m);			\
456 		if (__b & ~__m)						\
457 			pr_debug1(PPIP32 "%s: extra bits in %s(%s): "	\
458 				  "0x%02x/0x%02x\n",			\
459 				  (p)->name, __func__, #b, __b, __m);	\
460 	} while (0)
461 #else /* DEBUG_PARPORT_IP32 < 1 */
462 #define CHECK_EXTRA_BITS(...)	do { } while (0)
463 #endif
464 
465 /*--- IP32 parallel port DMA operations --------------------------------*/
466 
467 /**
468  * struct parport_ip32_dma_data - private data needed for DMA operation
469  * @dir:	DMA direction (from or to device)
470  * @buf:	buffer physical address
471  * @len:	buffer length
472  * @next:	address of next bytes to DMA transfer
473  * @left:	number of bytes remaining
474  * @ctx:	next context to write (0: context_a; 1: context_b)
475  * @irq_on:	are the DMA IRQs currently enabled?
476  * @lock:	spinlock to protect access to the structure
477  */
478 struct parport_ip32_dma_data {
479 	enum dma_data_direction		dir;
480 	dma_addr_t			buf;
481 	dma_addr_t			next;
482 	size_t				len;
483 	size_t				left;
484 	unsigned int			ctx;
485 	unsigned int			irq_on;
486 	spinlock_t			lock;
487 };
488 static struct parport_ip32_dma_data parport_ip32_dma;
489 
490 /**
491  * parport_ip32_dma_setup_context - setup next DMA context
492  * @limit:	maximum data size for the context
493  *
494  * The alignment constraints must be verified in caller function, and the
495  * parameter @limit must be set accordingly.
496  */
497 static void parport_ip32_dma_setup_context(unsigned int limit)
498 {
499 	unsigned long flags;
500 
501 	spin_lock_irqsave(&parport_ip32_dma.lock, flags);
502 	if (parport_ip32_dma.left > 0) {
503 		/* Note: ctxreg is "volatile" here only because
504 		 * mace->perif.ctrl.parport.context_a and context_b are
505 		 * "volatile".  */
506 		volatile u64 __iomem *ctxreg = (parport_ip32_dma.ctx == 0) ?
507 			&mace->perif.ctrl.parport.context_a :
508 			&mace->perif.ctrl.parport.context_b;
509 		u64 count;
510 		u64 ctxval;
511 		if (parport_ip32_dma.left <= limit) {
512 			count = parport_ip32_dma.left;
513 			ctxval = MACEPAR_CONTEXT_LASTFLAG;
514 		} else {
515 			count = limit;
516 			ctxval = 0;
517 		}
518 
519 		pr_trace(NULL,
520 			 "(%u): 0x%04x:0x%04x, %u -> %u%s",
521 			 limit,
522 			 (unsigned int)parport_ip32_dma.buf,
523 			 (unsigned int)parport_ip32_dma.next,
524 			 (unsigned int)count,
525 			 parport_ip32_dma.ctx, ctxval ? "*" : "");
526 
527 		ctxval |= parport_ip32_dma.next &
528 			MACEPAR_CONTEXT_BASEADDR_MASK;
529 		ctxval |= ((count - 1) << MACEPAR_CONTEXT_DATALEN_SHIFT) &
530 			MACEPAR_CONTEXT_DATALEN_MASK;
531 		writeq(ctxval, ctxreg);
532 		parport_ip32_dma.next += count;
533 		parport_ip32_dma.left -= count;
534 		parport_ip32_dma.ctx ^= 1U;
535 	}
536 	/* If there is nothing more to send, disable IRQs to avoid to
537 	 * face an IRQ storm which can lock the machine.  Disable them
538 	 * only once. */
539 	if (parport_ip32_dma.left == 0 && parport_ip32_dma.irq_on) {
540 		pr_debug(PPIP32 "IRQ off (ctx)\n");
541 		disable_irq_nosync(MACEISA_PAR_CTXA_IRQ);
542 		disable_irq_nosync(MACEISA_PAR_CTXB_IRQ);
543 		parport_ip32_dma.irq_on = 0;
544 	}
545 	spin_unlock_irqrestore(&parport_ip32_dma.lock, flags);
546 }
547 
548 /**
549  * parport_ip32_dma_interrupt - DMA interrupt handler
550  * @irq:	interrupt number
551  * @dev_id:	unused
552  */
553 static irqreturn_t parport_ip32_dma_interrupt(int irq, void *dev_id)
554 {
555 	if (parport_ip32_dma.left)
556 		pr_trace(NULL, "(%d): ctx=%d", irq, parport_ip32_dma.ctx);
557 	parport_ip32_dma_setup_context(MACEPAR_CONTEXT_DATA_BOUND);
558 	return IRQ_HANDLED;
559 }
560 
561 #if DEBUG_PARPORT_IP32
562 static irqreturn_t parport_ip32_merr_interrupt(int irq, void *dev_id)
563 {
564 	pr_trace1(NULL, "(%d)", irq);
565 	return IRQ_HANDLED;
566 }
567 #endif
568 
569 /**
570  * parport_ip32_dma_start - begins a DMA transfer
571  * @p:		partport to work on
572  * @dir:	DMA direction: DMA_TO_DEVICE or DMA_FROM_DEVICE
573  * @addr:	pointer to data buffer
574  * @count:	buffer size
575  *
576  * Calls to parport_ip32_dma_start() and parport_ip32_dma_stop() must be
577  * correctly balanced.
578  */
579 static int parport_ip32_dma_start(struct parport *p,
580 		enum dma_data_direction dir, void *addr, size_t count)
581 {
582 	unsigned int limit;
583 	u64 ctrl;
584 
585 	pr_trace(NULL, "(%d, %lu)", dir, (unsigned long)count);
586 
587 	/* FIXME - add support for DMA_FROM_DEVICE.  In this case, buffer must
588 	 * be 64 bytes aligned. */
589 	BUG_ON(dir != DMA_TO_DEVICE);
590 
591 	/* Reset DMA controller */
592 	ctrl = MACEPAR_CTLSTAT_RESET;
593 	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
594 
595 	/* DMA IRQs should normally be enabled */
596 	if (!parport_ip32_dma.irq_on) {
597 		WARN_ON(1);
598 		enable_irq(MACEISA_PAR_CTXA_IRQ);
599 		enable_irq(MACEISA_PAR_CTXB_IRQ);
600 		parport_ip32_dma.irq_on = 1;
601 	}
602 
603 	/* Prepare DMA pointers */
604 	parport_ip32_dma.dir = dir;
605 	parport_ip32_dma.buf = dma_map_single(&p->bus_dev, addr, count, dir);
606 	parport_ip32_dma.len = count;
607 	parport_ip32_dma.next = parport_ip32_dma.buf;
608 	parport_ip32_dma.left = parport_ip32_dma.len;
609 	parport_ip32_dma.ctx = 0;
610 
611 	/* Setup DMA direction and first two contexts */
612 	ctrl = (dir == DMA_TO_DEVICE) ? 0 : MACEPAR_CTLSTAT_DIRECTION;
613 	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
614 	/* Single transfer should not cross a 4K page boundary */
615 	limit = MACEPAR_CONTEXT_DATA_BOUND -
616 		(parport_ip32_dma.next & (MACEPAR_CONTEXT_DATA_BOUND - 1));
617 	parport_ip32_dma_setup_context(limit);
618 	parport_ip32_dma_setup_context(MACEPAR_CONTEXT_DATA_BOUND);
619 
620 	/* Real start of DMA transfer */
621 	ctrl |= MACEPAR_CTLSTAT_ENABLE;
622 	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
623 
624 	return 0;
625 }
626 
627 /**
628  * parport_ip32_dma_stop - ends a running DMA transfer
629  * @p:		partport to work on
630  *
631  * Calls to parport_ip32_dma_start() and parport_ip32_dma_stop() must be
632  * correctly balanced.
633  */
634 static void parport_ip32_dma_stop(struct parport *p)
635 {
636 	u64 ctx_a;
637 	u64 ctx_b;
638 	u64 ctrl;
639 	u64 diag;
640 	size_t res[2];	/* {[0] = res_a, [1] = res_b} */
641 
642 	pr_trace(NULL, "()");
643 
644 	/* Disable IRQs */
645 	spin_lock_irq(&parport_ip32_dma.lock);
646 	if (parport_ip32_dma.irq_on) {
647 		pr_debug(PPIP32 "IRQ off (stop)\n");
648 		disable_irq_nosync(MACEISA_PAR_CTXA_IRQ);
649 		disable_irq_nosync(MACEISA_PAR_CTXB_IRQ);
650 		parport_ip32_dma.irq_on = 0;
651 	}
652 	spin_unlock_irq(&parport_ip32_dma.lock);
653 	/* Force IRQ synchronization, even if the IRQs were disabled
654 	 * elsewhere. */
655 	synchronize_irq(MACEISA_PAR_CTXA_IRQ);
656 	synchronize_irq(MACEISA_PAR_CTXB_IRQ);
657 
658 	/* Stop DMA transfer */
659 	ctrl = readq(&mace->perif.ctrl.parport.cntlstat);
660 	ctrl &= ~MACEPAR_CTLSTAT_ENABLE;
661 	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
662 
663 	/* Adjust residue (parport_ip32_dma.left) */
664 	ctx_a = readq(&mace->perif.ctrl.parport.context_a);
665 	ctx_b = readq(&mace->perif.ctrl.parport.context_b);
666 	ctrl = readq(&mace->perif.ctrl.parport.cntlstat);
667 	diag = readq(&mace->perif.ctrl.parport.diagnostic);
668 	res[0] = (ctrl & MACEPAR_CTLSTAT_CTXA_VALID) ?
669 		1 + ((ctx_a & MACEPAR_CONTEXT_DATALEN_MASK) >>
670 		     MACEPAR_CONTEXT_DATALEN_SHIFT) :
671 		0;
672 	res[1] = (ctrl & MACEPAR_CTLSTAT_CTXB_VALID) ?
673 		1 + ((ctx_b & MACEPAR_CONTEXT_DATALEN_MASK) >>
674 		     MACEPAR_CONTEXT_DATALEN_SHIFT) :
675 		0;
676 	if (diag & MACEPAR_DIAG_DMACTIVE)
677 		res[(diag & MACEPAR_DIAG_CTXINUSE) != 0] =
678 			1 + ((diag & MACEPAR_DIAG_CTRMASK) >>
679 			     MACEPAR_DIAG_CTRSHIFT);
680 	parport_ip32_dma.left += res[0] + res[1];
681 
682 	/* Reset DMA controller, and re-enable IRQs */
683 	ctrl = MACEPAR_CTLSTAT_RESET;
684 	writeq(ctrl, &mace->perif.ctrl.parport.cntlstat);
685 	pr_debug(PPIP32 "IRQ on (stop)\n");
686 	enable_irq(MACEISA_PAR_CTXA_IRQ);
687 	enable_irq(MACEISA_PAR_CTXB_IRQ);
688 	parport_ip32_dma.irq_on = 1;
689 
690 	dma_unmap_single(&p->bus_dev, parport_ip32_dma.buf,
691 			 parport_ip32_dma.len, parport_ip32_dma.dir);
692 }
693 
694 /**
695  * parport_ip32_dma_get_residue - get residue from last DMA transfer
696  *
697  * Returns the number of bytes remaining from last DMA transfer.
698  */
699 static inline size_t parport_ip32_dma_get_residue(void)
700 {
701 	return parport_ip32_dma.left;
702 }
703 
704 /**
705  * parport_ip32_dma_register - initialize DMA engine
706  *
707  * Returns zero for success.
708  */
709 static int parport_ip32_dma_register(void)
710 {
711 	int err;
712 
713 	spin_lock_init(&parport_ip32_dma.lock);
714 	parport_ip32_dma.irq_on = 1;
715 
716 	/* Reset DMA controller */
717 	writeq(MACEPAR_CTLSTAT_RESET, &mace->perif.ctrl.parport.cntlstat);
718 
719 	/* Request IRQs */
720 	err = request_irq(MACEISA_PAR_CTXA_IRQ, parport_ip32_dma_interrupt,
721 			  0, "parport_ip32", NULL);
722 	if (err)
723 		goto fail_a;
724 	err = request_irq(MACEISA_PAR_CTXB_IRQ, parport_ip32_dma_interrupt,
725 			  0, "parport_ip32", NULL);
726 	if (err)
727 		goto fail_b;
728 #if DEBUG_PARPORT_IP32
729 	/* FIXME - what is this IRQ for? */
730 	err = request_irq(MACEISA_PAR_MERR_IRQ, parport_ip32_merr_interrupt,
731 			  0, "parport_ip32", NULL);
732 	if (err)
733 		goto fail_merr;
734 #endif
735 	return 0;
736 
737 #if DEBUG_PARPORT_IP32
738 fail_merr:
739 	free_irq(MACEISA_PAR_CTXB_IRQ, NULL);
740 #endif
741 fail_b:
742 	free_irq(MACEISA_PAR_CTXA_IRQ, NULL);
743 fail_a:
744 	return err;
745 }
746 
747 /**
748  * parport_ip32_dma_unregister - release and free resources for DMA engine
749  */
750 static void parport_ip32_dma_unregister(void)
751 {
752 #if DEBUG_PARPORT_IP32
753 	free_irq(MACEISA_PAR_MERR_IRQ, NULL);
754 #endif
755 	free_irq(MACEISA_PAR_CTXB_IRQ, NULL);
756 	free_irq(MACEISA_PAR_CTXA_IRQ, NULL);
757 }
758 
759 /*--- Interrupt handlers and associates --------------------------------*/
760 
761 /**
762  * parport_ip32_wakeup - wakes up code waiting for an interrupt
763  * @p:		pointer to &struct parport
764  */
765 static inline void parport_ip32_wakeup(struct parport *p)
766 {
767 	struct parport_ip32_private * const priv = p->physport->private_data;
768 	complete(&priv->irq_complete);
769 }
770 
771 /**
772  * parport_ip32_interrupt - interrupt handler
773  * @irq:	interrupt number
774  * @dev_id:	pointer to &struct parport
775  *
776  * Caught interrupts are forwarded to the upper parport layer if IRQ_mode is
777  * %PARPORT_IP32_IRQ_FWD.
778  */
779 static irqreturn_t parport_ip32_interrupt(int irq, void *dev_id)
780 {
781 	struct parport * const p = dev_id;
782 	struct parport_ip32_private * const priv = p->physport->private_data;
783 	enum parport_ip32_irq_mode irq_mode = priv->irq_mode;
784 
785 	switch (irq_mode) {
786 	case PARPORT_IP32_IRQ_FWD:
787 		return parport_irq_handler(irq, dev_id);
788 
789 	case PARPORT_IP32_IRQ_HERE:
790 		parport_ip32_wakeup(p);
791 		break;
792 	}
793 
794 	return IRQ_HANDLED;
795 }
796 
797 /*--- Some utility function to manipulate ECR register -----------------*/
798 
799 /**
800  * parport_ip32_read_econtrol - read contents of the ECR register
801  * @p:		pointer to &struct parport
802  */
803 static inline unsigned int parport_ip32_read_econtrol(struct parport *p)
804 {
805 	struct parport_ip32_private * const priv = p->physport->private_data;
806 	return readb(priv->regs.ecr);
807 }
808 
809 /**
810  * parport_ip32_write_econtrol - write new contents to the ECR register
811  * @p:		pointer to &struct parport
812  * @c:		new value to write
813  */
814 static inline void parport_ip32_write_econtrol(struct parport *p,
815 					       unsigned int c)
816 {
817 	struct parport_ip32_private * const priv = p->physport->private_data;
818 	writeb(c, priv->regs.ecr);
819 }
820 
821 /**
822  * parport_ip32_frob_econtrol - change bits from the ECR register
823  * @p:		pointer to &struct parport
824  * @mask:	bit mask of bits to change
825  * @val:	new value for changed bits
826  *
827  * Read from the ECR, mask out the bits in @mask, exclusive-or with the bits
828  * in @val, and write the result to the ECR.
829  */
830 static inline void parport_ip32_frob_econtrol(struct parport *p,
831 					      unsigned int mask,
832 					      unsigned int val)
833 {
834 	unsigned int c;
835 	c = (parport_ip32_read_econtrol(p) & ~mask) ^ val;
836 	parport_ip32_write_econtrol(p, c);
837 }
838 
839 /**
840  * parport_ip32_set_mode - change mode of ECP port
841  * @p:		pointer to &struct parport
842  * @mode:	new mode to write in ECR
843  *
844  * ECR is reset in a sane state (interrupts and DMA disabled), and placed in
845  * mode @mode.  Go through PS2 mode if needed.
846  */
847 static void parport_ip32_set_mode(struct parport *p, unsigned int mode)
848 {
849 	unsigned int omode;
850 
851 	mode &= ECR_MODE_MASK;
852 	omode = parport_ip32_read_econtrol(p) & ECR_MODE_MASK;
853 
854 	if (!(mode == ECR_MODE_SPP || mode == ECR_MODE_PS2
855 	      || omode == ECR_MODE_SPP || omode == ECR_MODE_PS2)) {
856 		/* We have to go through PS2 mode */
857 		unsigned int ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
858 		parport_ip32_write_econtrol(p, ecr);
859 	}
860 	parport_ip32_write_econtrol(p, mode | ECR_nERRINTR | ECR_SERVINTR);
861 }
862 
863 /*--- Basic functions needed for parport -------------------------------*/
864 
865 /**
866  * parport_ip32_read_data - return current contents of the DATA register
867  * @p:		pointer to &struct parport
868  */
869 static inline unsigned char parport_ip32_read_data(struct parport *p)
870 {
871 	struct parport_ip32_private * const priv = p->physport->private_data;
872 	return readb(priv->regs.data);
873 }
874 
875 /**
876  * parport_ip32_write_data - set new contents for the DATA register
877  * @p:		pointer to &struct parport
878  * @d:		new value to write
879  */
880 static inline void parport_ip32_write_data(struct parport *p, unsigned char d)
881 {
882 	struct parport_ip32_private * const priv = p->physport->private_data;
883 	writeb(d, priv->regs.data);
884 }
885 
886 /**
887  * parport_ip32_read_status - return current contents of the DSR register
888  * @p:		pointer to &struct parport
889  */
890 static inline unsigned char parport_ip32_read_status(struct parport *p)
891 {
892 	struct parport_ip32_private * const priv = p->physport->private_data;
893 	return readb(priv->regs.dsr);
894 }
895 
896 /**
897  * __parport_ip32_read_control - return cached contents of the DCR register
898  * @p:		pointer to &struct parport
899  */
900 static inline unsigned int __parport_ip32_read_control(struct parport *p)
901 {
902 	struct parport_ip32_private * const priv = p->physport->private_data;
903 	return priv->dcr_cache; /* use soft copy */
904 }
905 
906 /**
907  * __parport_ip32_write_control - set new contents for the DCR register
908  * @p:		pointer to &struct parport
909  * @c:		new value to write
910  */
911 static inline void __parport_ip32_write_control(struct parport *p,
912 						unsigned int c)
913 {
914 	struct parport_ip32_private * const priv = p->physport->private_data;
915 	CHECK_EXTRA_BITS(p, c, priv->dcr_writable);
916 	c &= priv->dcr_writable; /* only writable bits */
917 	writeb(c, priv->regs.dcr);
918 	priv->dcr_cache = c;		/* update soft copy */
919 }
920 
921 /**
922  * __parport_ip32_frob_control - change bits from the DCR register
923  * @p:		pointer to &struct parport
924  * @mask:	bit mask of bits to change
925  * @val:	new value for changed bits
926  *
927  * This is equivalent to read from the DCR, mask out the bits in @mask,
928  * exclusive-or with the bits in @val, and write the result to the DCR.
929  * Actually, the cached contents of the DCR is used.
930  */
931 static inline void __parport_ip32_frob_control(struct parport *p,
932 					       unsigned int mask,
933 					       unsigned int val)
934 {
935 	unsigned int c;
936 	c = (__parport_ip32_read_control(p) & ~mask) ^ val;
937 	__parport_ip32_write_control(p, c);
938 }
939 
940 /**
941  * parport_ip32_read_control - return cached contents of the DCR register
942  * @p:		pointer to &struct parport
943  *
944  * The return value is masked so as to only return the value of %DCR_STROBE,
945  * %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
946  */
947 static inline unsigned char parport_ip32_read_control(struct parport *p)
948 {
949 	const unsigned int rm =
950 		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
951 	return __parport_ip32_read_control(p) & rm;
952 }
953 
954 /**
955  * parport_ip32_write_control - set new contents for the DCR register
956  * @p:		pointer to &struct parport
957  * @c:		new value to write
958  *
959  * The value is masked so as to only change the value of %DCR_STROBE,
960  * %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
961  */
962 static inline void parport_ip32_write_control(struct parport *p,
963 					      unsigned char c)
964 {
965 	const unsigned int wm =
966 		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
967 	CHECK_EXTRA_BITS(p, c, wm);
968 	__parport_ip32_frob_control(p, wm, c & wm);
969 }
970 
971 /**
972  * parport_ip32_frob_control - change bits from the DCR register
973  * @p:		pointer to &struct parport
974  * @mask:	bit mask of bits to change
975  * @val:	new value for changed bits
976  *
977  * This differs from __parport_ip32_frob_control() in that it only allows to
978  * change the value of %DCR_STROBE, %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
979  */
980 static inline unsigned char parport_ip32_frob_control(struct parport *p,
981 						      unsigned char mask,
982 						      unsigned char val)
983 {
984 	const unsigned int wm =
985 		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
986 	CHECK_EXTRA_BITS(p, mask, wm);
987 	CHECK_EXTRA_BITS(p, val, wm);
988 	__parport_ip32_frob_control(p, mask & wm, val & wm);
989 	return parport_ip32_read_control(p);
990 }
991 
992 /**
993  * parport_ip32_disable_irq - disable interrupts on the rising edge of nACK
994  * @p:		pointer to &struct parport
995  */
996 static inline void parport_ip32_disable_irq(struct parport *p)
997 {
998 	__parport_ip32_frob_control(p, DCR_IRQ, 0);
999 }
1000 
1001 /**
1002  * parport_ip32_enable_irq - enable interrupts on the rising edge of nACK
1003  * @p:		pointer to &struct parport
1004  */
1005 static inline void parport_ip32_enable_irq(struct parport *p)
1006 {
1007 	__parport_ip32_frob_control(p, DCR_IRQ, DCR_IRQ);
1008 }
1009 
1010 /**
1011  * parport_ip32_data_forward - enable host-to-peripheral communications
1012  * @p:		pointer to &struct parport
1013  *
1014  * Enable the data line drivers, for 8-bit host-to-peripheral communications.
1015  */
1016 static inline void parport_ip32_data_forward(struct parport *p)
1017 {
1018 	__parport_ip32_frob_control(p, DCR_DIR, 0);
1019 }
1020 
1021 /**
1022  * parport_ip32_data_reverse - enable peripheral-to-host communications
1023  * @p:		pointer to &struct parport
1024  *
1025  * Place the data bus in a high impedance state, if @p->modes has the
1026  * PARPORT_MODE_TRISTATE bit set.
1027  */
1028 static inline void parport_ip32_data_reverse(struct parport *p)
1029 {
1030 	__parport_ip32_frob_control(p, DCR_DIR, DCR_DIR);
1031 }
1032 
1033 /**
1034  * parport_ip32_init_state - for core parport code
1035  * @dev:	pointer to &struct pardevice
1036  * @s:		pointer to &struct parport_state to initialize
1037  */
1038 static void parport_ip32_init_state(struct pardevice *dev,
1039 				    struct parport_state *s)
1040 {
1041 	s->u.ip32.dcr = DCR_SELECT | DCR_nINIT;
1042 	s->u.ip32.ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
1043 }
1044 
1045 /**
1046  * parport_ip32_save_state - for core parport code
1047  * @p:		pointer to &struct parport
1048  * @s:		pointer to &struct parport_state to save state to
1049  */
1050 static void parport_ip32_save_state(struct parport *p,
1051 				    struct parport_state *s)
1052 {
1053 	s->u.ip32.dcr = __parport_ip32_read_control(p);
1054 	s->u.ip32.ecr = parport_ip32_read_econtrol(p);
1055 }
1056 
1057 /**
1058  * parport_ip32_restore_state - for core parport code
1059  * @p:		pointer to &struct parport
1060  * @s:		pointer to &struct parport_state to restore state from
1061  */
1062 static void parport_ip32_restore_state(struct parport *p,
1063 				       struct parport_state *s)
1064 {
1065 	parport_ip32_set_mode(p, s->u.ip32.ecr & ECR_MODE_MASK);
1066 	parport_ip32_write_econtrol(p, s->u.ip32.ecr);
1067 	__parport_ip32_write_control(p, s->u.ip32.dcr);
1068 }
1069 
1070 /*--- EPP mode functions -----------------------------------------------*/
1071 
1072 /**
1073  * parport_ip32_clear_epp_timeout - clear Timeout bit in EPP mode
1074  * @p:		pointer to &struct parport
1075  *
1076  * Returns 1 if the Timeout bit is clear, and 0 otherwise.
1077  */
1078 static unsigned int parport_ip32_clear_epp_timeout(struct parport *p)
1079 {
1080 	struct parport_ip32_private * const priv = p->physport->private_data;
1081 	unsigned int cleared;
1082 
1083 	if (!(parport_ip32_read_status(p) & DSR_TIMEOUT))
1084 		cleared = 1;
1085 	else {
1086 		unsigned int r;
1087 		/* To clear timeout some chips require double read */
1088 		parport_ip32_read_status(p);
1089 		r = parport_ip32_read_status(p);
1090 		/* Some reset by writing 1 */
1091 		writeb(r | DSR_TIMEOUT, priv->regs.dsr);
1092 		/* Others by writing 0 */
1093 		writeb(r & ~DSR_TIMEOUT, priv->regs.dsr);
1094 
1095 		r = parport_ip32_read_status(p);
1096 		cleared = !(r & DSR_TIMEOUT);
1097 	}
1098 
1099 	pr_trace(p, "(): %s", cleared ? "cleared" : "failed");
1100 	return cleared;
1101 }
1102 
1103 /**
1104  * parport_ip32_epp_read - generic EPP read function
1105  * @eppreg:	I/O register to read from
1106  * @p:		pointer to &struct parport
1107  * @buf:	buffer to store read data
1108  * @len:	length of buffer @buf
1109  * @flags:	may be PARPORT_EPP_FAST
1110  */
1111 static size_t parport_ip32_epp_read(void __iomem *eppreg,
1112 				    struct parport *p, void *buf,
1113 				    size_t len, int flags)
1114 {
1115 	struct parport_ip32_private * const priv = p->physport->private_data;
1116 	size_t got;
1117 	parport_ip32_set_mode(p, ECR_MODE_EPP);
1118 	parport_ip32_data_reverse(p);
1119 	parport_ip32_write_control(p, DCR_nINIT);
1120 	if ((flags & PARPORT_EPP_FAST) && (len > 1)) {
1121 		readsb(eppreg, buf, len);
1122 		if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1123 			parport_ip32_clear_epp_timeout(p);
1124 			return -EIO;
1125 		}
1126 		got = len;
1127 	} else {
1128 		u8 *bufp = buf;
1129 		for (got = 0; got < len; got++) {
1130 			*bufp++ = readb(eppreg);
1131 			if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1132 				parport_ip32_clear_epp_timeout(p);
1133 				break;
1134 			}
1135 		}
1136 	}
1137 	parport_ip32_data_forward(p);
1138 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1139 	return got;
1140 }
1141 
1142 /**
1143  * parport_ip32_epp_write - generic EPP write function
1144  * @eppreg:	I/O register to write to
1145  * @p:		pointer to &struct parport
1146  * @buf:	buffer of data to write
1147  * @len:	length of buffer @buf
1148  * @flags:	may be PARPORT_EPP_FAST
1149  */
1150 static size_t parport_ip32_epp_write(void __iomem *eppreg,
1151 				     struct parport *p, const void *buf,
1152 				     size_t len, int flags)
1153 {
1154 	struct parport_ip32_private * const priv = p->physport->private_data;
1155 	size_t written;
1156 	parport_ip32_set_mode(p, ECR_MODE_EPP);
1157 	parport_ip32_data_forward(p);
1158 	parport_ip32_write_control(p, DCR_nINIT);
1159 	if ((flags & PARPORT_EPP_FAST) && (len > 1)) {
1160 		writesb(eppreg, buf, len);
1161 		if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1162 			parport_ip32_clear_epp_timeout(p);
1163 			return -EIO;
1164 		}
1165 		written = len;
1166 	} else {
1167 		const u8 *bufp = buf;
1168 		for (written = 0; written < len; written++) {
1169 			writeb(*bufp++, eppreg);
1170 			if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1171 				parport_ip32_clear_epp_timeout(p);
1172 				break;
1173 			}
1174 		}
1175 	}
1176 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1177 	return written;
1178 }
1179 
1180 /**
1181  * parport_ip32_epp_read_data - read a block of data in EPP mode
1182  * @p:		pointer to &struct parport
1183  * @buf:	buffer to store read data
1184  * @len:	length of buffer @buf
1185  * @flags:	may be PARPORT_EPP_FAST
1186  */
1187 static size_t parport_ip32_epp_read_data(struct parport *p, void *buf,
1188 					 size_t len, int flags)
1189 {
1190 	struct parport_ip32_private * const priv = p->physport->private_data;
1191 	return parport_ip32_epp_read(priv->regs.eppData0, p, buf, len, flags);
1192 }
1193 
1194 /**
1195  * parport_ip32_epp_write_data - write a block of data in EPP mode
1196  * @p:		pointer to &struct parport
1197  * @buf:	buffer of data to write
1198  * @len:	length of buffer @buf
1199  * @flags:	may be PARPORT_EPP_FAST
1200  */
1201 static size_t parport_ip32_epp_write_data(struct parport *p, const void *buf,
1202 					  size_t len, int flags)
1203 {
1204 	struct parport_ip32_private * const priv = p->physport->private_data;
1205 	return parport_ip32_epp_write(priv->regs.eppData0, p, buf, len, flags);
1206 }
1207 
1208 /**
1209  * parport_ip32_epp_read_addr - read a block of addresses in EPP mode
1210  * @p:		pointer to &struct parport
1211  * @buf:	buffer to store read data
1212  * @len:	length of buffer @buf
1213  * @flags:	may be PARPORT_EPP_FAST
1214  */
1215 static size_t parport_ip32_epp_read_addr(struct parport *p, void *buf,
1216 					 size_t len, int flags)
1217 {
1218 	struct parport_ip32_private * const priv = p->physport->private_data;
1219 	return parport_ip32_epp_read(priv->regs.eppAddr, p, buf, len, flags);
1220 }
1221 
1222 /**
1223  * parport_ip32_epp_write_addr - write a block of addresses in EPP mode
1224  * @p:		pointer to &struct parport
1225  * @buf:	buffer of data to write
1226  * @len:	length of buffer @buf
1227  * @flags:	may be PARPORT_EPP_FAST
1228  */
1229 static size_t parport_ip32_epp_write_addr(struct parport *p, const void *buf,
1230 					  size_t len, int flags)
1231 {
1232 	struct parport_ip32_private * const priv = p->physport->private_data;
1233 	return parport_ip32_epp_write(priv->regs.eppAddr, p, buf, len, flags);
1234 }
1235 
1236 /*--- ECP mode functions (FIFO) ----------------------------------------*/
1237 
1238 /**
1239  * parport_ip32_fifo_wait_break - check if the waiting function should return
1240  * @p:		pointer to &struct parport
1241  * @expire:	timeout expiring date, in jiffies
1242  *
1243  * parport_ip32_fifo_wait_break() checks if the waiting function should return
1244  * immediately or not.  The break conditions are:
1245  *	- expired timeout;
1246  *	- a pending signal;
1247  *	- nFault asserted low.
1248  * This function also calls cond_resched().
1249  */
1250 static unsigned int parport_ip32_fifo_wait_break(struct parport *p,
1251 						 unsigned long expire)
1252 {
1253 	cond_resched();
1254 	if (time_after(jiffies, expire)) {
1255 		pr_debug1(PPIP32 "%s: FIFO write timed out\n", p->name);
1256 		return 1;
1257 	}
1258 	if (signal_pending(current)) {
1259 		pr_debug1(PPIP32 "%s: Signal pending\n", p->name);
1260 		return 1;
1261 	}
1262 	if (!(parport_ip32_read_status(p) & DSR_nFAULT)) {
1263 		pr_debug1(PPIP32 "%s: nFault asserted low\n", p->name);
1264 		return 1;
1265 	}
1266 	return 0;
1267 }
1268 
1269 /**
1270  * parport_ip32_fwp_wait_polling - wait for FIFO to empty (polling)
1271  * @p:		pointer to &struct parport
1272  *
1273  * Returns the number of bytes that can safely be written in the FIFO.  A
1274  * return value of zero means that the calling function should terminate as
1275  * fast as possible.
1276  */
1277 static unsigned int parport_ip32_fwp_wait_polling(struct parport *p)
1278 {
1279 	struct parport_ip32_private * const priv = p->physport->private_data;
1280 	struct parport * const physport = p->physport;
1281 	unsigned long expire;
1282 	unsigned int count;
1283 	unsigned int ecr;
1284 
1285 	expire = jiffies + physport->cad->timeout;
1286 	count = 0;
1287 	while (1) {
1288 		if (parport_ip32_fifo_wait_break(p, expire))
1289 			break;
1290 
1291 		/* Check FIFO state.  We do nothing when the FIFO is nor full,
1292 		 * nor empty.  It appears that the FIFO full bit is not always
1293 		 * reliable, the FIFO state is sometimes wrongly reported, and
1294 		 * the chip gets confused if we give it another byte. */
1295 		ecr = parport_ip32_read_econtrol(p);
1296 		if (ecr & ECR_F_EMPTY) {
1297 			/* FIFO is empty, fill it up */
1298 			count = priv->fifo_depth;
1299 			break;
1300 		}
1301 
1302 		/* Wait a moment... */
1303 		udelay(FIFO_POLLING_INTERVAL);
1304 	} /* while (1) */
1305 
1306 	return count;
1307 }
1308 
1309 /**
1310  * parport_ip32_fwp_wait_interrupt - wait for FIFO to empty (interrupt-driven)
1311  * @p:		pointer to &struct parport
1312  *
1313  * Returns the number of bytes that can safely be written in the FIFO.  A
1314  * return value of zero means that the calling function should terminate as
1315  * fast as possible.
1316  */
1317 static unsigned int parport_ip32_fwp_wait_interrupt(struct parport *p)
1318 {
1319 	static unsigned int lost_interrupt = 0;
1320 	struct parport_ip32_private * const priv = p->physport->private_data;
1321 	struct parport * const physport = p->physport;
1322 	unsigned long nfault_timeout;
1323 	unsigned long expire;
1324 	unsigned int count;
1325 	unsigned int ecr;
1326 
1327 	nfault_timeout = min((unsigned long)physport->cad->timeout,
1328 			     msecs_to_jiffies(FIFO_NFAULT_TIMEOUT));
1329 	expire = jiffies + physport->cad->timeout;
1330 	count = 0;
1331 	while (1) {
1332 		if (parport_ip32_fifo_wait_break(p, expire))
1333 			break;
1334 
1335 		/* Initialize mutex used to take interrupts into account */
1336 		reinit_completion(&priv->irq_complete);
1337 
1338 		/* Enable serviceIntr */
1339 		parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
1340 
1341 		/* Enabling serviceIntr while the FIFO is empty does not
1342 		 * always generate an interrupt, so check for emptiness
1343 		 * now. */
1344 		ecr = parport_ip32_read_econtrol(p);
1345 		if (!(ecr & ECR_F_EMPTY)) {
1346 			/* FIFO is not empty: wait for an interrupt or a
1347 			 * timeout to occur */
1348 			wait_for_completion_interruptible_timeout(
1349 				&priv->irq_complete, nfault_timeout);
1350 			ecr = parport_ip32_read_econtrol(p);
1351 			if ((ecr & ECR_F_EMPTY) && !(ecr & ECR_SERVINTR)
1352 			    && !lost_interrupt) {
1353 				printk(KERN_WARNING PPIP32
1354 				       "%s: lost interrupt in %s\n",
1355 				       p->name, __func__);
1356 				lost_interrupt = 1;
1357 			}
1358 		}
1359 
1360 		/* Disable serviceIntr */
1361 		parport_ip32_frob_econtrol(p, ECR_SERVINTR, ECR_SERVINTR);
1362 
1363 		/* Check FIFO state */
1364 		if (ecr & ECR_F_EMPTY) {
1365 			/* FIFO is empty, fill it up */
1366 			count = priv->fifo_depth;
1367 			break;
1368 		} else if (ecr & ECR_SERVINTR) {
1369 			/* FIFO is not empty, but we know that can safely push
1370 			 * writeIntrThreshold bytes into it */
1371 			count = priv->writeIntrThreshold;
1372 			break;
1373 		}
1374 		/* FIFO is not empty, and we did not get any interrupt.
1375 		 * Either it's time to check for nFault, or a signal is
1376 		 * pending.  This is verified in
1377 		 * parport_ip32_fifo_wait_break(), so we continue the loop. */
1378 	} /* while (1) */
1379 
1380 	return count;
1381 }
1382 
1383 /**
1384  * parport_ip32_fifo_write_block_pio - write a block of data (PIO mode)
1385  * @p:		pointer to &struct parport
1386  * @buf:	buffer of data to write
1387  * @len:	length of buffer @buf
1388  *
1389  * Uses PIO to write the contents of the buffer @buf into the parallel port
1390  * FIFO.  Returns the number of bytes that were actually written.  It can work
1391  * with or without the help of interrupts.  The parallel port must be
1392  * correctly initialized before calling parport_ip32_fifo_write_block_pio().
1393  */
1394 static size_t parport_ip32_fifo_write_block_pio(struct parport *p,
1395 						const void *buf, size_t len)
1396 {
1397 	struct parport_ip32_private * const priv = p->physport->private_data;
1398 	const u8 *bufp = buf;
1399 	size_t left = len;
1400 
1401 	priv->irq_mode = PARPORT_IP32_IRQ_HERE;
1402 
1403 	while (left > 0) {
1404 		unsigned int count;
1405 
1406 		count = (p->irq == PARPORT_IRQ_NONE) ?
1407 			parport_ip32_fwp_wait_polling(p) :
1408 			parport_ip32_fwp_wait_interrupt(p);
1409 		if (count == 0)
1410 			break;	/* Transmission should be stopped */
1411 		if (count > left)
1412 			count = left;
1413 		if (count == 1) {
1414 			writeb(*bufp, priv->regs.fifo);
1415 			bufp++, left--;
1416 		} else {
1417 			writesb(priv->regs.fifo, bufp, count);
1418 			bufp += count, left -= count;
1419 		}
1420 	}
1421 
1422 	priv->irq_mode = PARPORT_IP32_IRQ_FWD;
1423 
1424 	return len - left;
1425 }
1426 
1427 /**
1428  * parport_ip32_fifo_write_block_dma - write a block of data (DMA mode)
1429  * @p:		pointer to &struct parport
1430  * @buf:	buffer of data to write
1431  * @len:	length of buffer @buf
1432  *
1433  * Uses DMA to write the contents of the buffer @buf into the parallel port
1434  * FIFO.  Returns the number of bytes that were actually written.  The
1435  * parallel port must be correctly initialized before calling
1436  * parport_ip32_fifo_write_block_dma().
1437  */
1438 static size_t parport_ip32_fifo_write_block_dma(struct parport *p,
1439 						const void *buf, size_t len)
1440 {
1441 	struct parport_ip32_private * const priv = p->physport->private_data;
1442 	struct parport * const physport = p->physport;
1443 	unsigned long nfault_timeout;
1444 	unsigned long expire;
1445 	size_t written;
1446 	unsigned int ecr;
1447 
1448 	priv->irq_mode = PARPORT_IP32_IRQ_HERE;
1449 
1450 	parport_ip32_dma_start(p, DMA_TO_DEVICE, (void *)buf, len);
1451 	reinit_completion(&priv->irq_complete);
1452 	parport_ip32_frob_econtrol(p, ECR_DMAEN | ECR_SERVINTR, ECR_DMAEN);
1453 
1454 	nfault_timeout = min((unsigned long)physport->cad->timeout,
1455 			     msecs_to_jiffies(FIFO_NFAULT_TIMEOUT));
1456 	expire = jiffies + physport->cad->timeout;
1457 	while (1) {
1458 		if (parport_ip32_fifo_wait_break(p, expire))
1459 			break;
1460 		wait_for_completion_interruptible_timeout(&priv->irq_complete,
1461 							  nfault_timeout);
1462 		ecr = parport_ip32_read_econtrol(p);
1463 		if (ecr & ECR_SERVINTR)
1464 			break;	/* DMA transfer just finished */
1465 	}
1466 	parport_ip32_dma_stop(p);
1467 	written = len - parport_ip32_dma_get_residue();
1468 
1469 	priv->irq_mode = PARPORT_IP32_IRQ_FWD;
1470 
1471 	return written;
1472 }
1473 
1474 /**
1475  * parport_ip32_fifo_write_block - write a block of data
1476  * @p:		pointer to &struct parport
1477  * @buf:	buffer of data to write
1478  * @len:	length of buffer @buf
1479  *
1480  * Uses PIO or DMA to write the contents of the buffer @buf into the parallel
1481  * p FIFO.  Returns the number of bytes that were actually written.
1482  */
1483 static size_t parport_ip32_fifo_write_block(struct parport *p,
1484 					    const void *buf, size_t len)
1485 {
1486 	size_t written = 0;
1487 	if (len)
1488 		/* FIXME - Maybe some threshold value should be set for @len
1489 		 * under which we revert to PIO mode? */
1490 		written = (p->modes & PARPORT_MODE_DMA) ?
1491 			parport_ip32_fifo_write_block_dma(p, buf, len) :
1492 			parport_ip32_fifo_write_block_pio(p, buf, len);
1493 	return written;
1494 }
1495 
1496 /**
1497  * parport_ip32_drain_fifo - wait for FIFO to empty
1498  * @p:		pointer to &struct parport
1499  * @timeout:	timeout, in jiffies
1500  *
1501  * This function waits for FIFO to empty.  It returns 1 when FIFO is empty, or
1502  * 0 if the timeout @timeout is reached before, or if a signal is pending.
1503  */
1504 static unsigned int parport_ip32_drain_fifo(struct parport *p,
1505 					    unsigned long timeout)
1506 {
1507 	unsigned long expire = jiffies + timeout;
1508 	unsigned int polling_interval;
1509 	unsigned int counter;
1510 
1511 	/* Busy wait for approx. 200us */
1512 	for (counter = 0; counter < 40; counter++) {
1513 		if (parport_ip32_read_econtrol(p) & ECR_F_EMPTY)
1514 			break;
1515 		if (time_after(jiffies, expire))
1516 			break;
1517 		if (signal_pending(current))
1518 			break;
1519 		udelay(5);
1520 	}
1521 	/* Poll slowly.  Polling interval starts with 1 millisecond, and is
1522 	 * increased exponentially until 128.  */
1523 	polling_interval = 1; /* msecs */
1524 	while (!(parport_ip32_read_econtrol(p) & ECR_F_EMPTY)) {
1525 		if (time_after_eq(jiffies, expire))
1526 			break;
1527 		msleep_interruptible(polling_interval);
1528 		if (signal_pending(current))
1529 			break;
1530 		if (polling_interval < 128)
1531 			polling_interval *= 2;
1532 	}
1533 
1534 	return !!(parport_ip32_read_econtrol(p) & ECR_F_EMPTY);
1535 }
1536 
1537 /**
1538  * parport_ip32_get_fifo_residue - reset FIFO
1539  * @p:		pointer to &struct parport
1540  * @mode:	current operation mode (ECR_MODE_PPF or ECR_MODE_ECP)
1541  *
1542  * This function resets FIFO, and returns the number of bytes remaining in it.
1543  */
1544 static unsigned int parport_ip32_get_fifo_residue(struct parport *p,
1545 						  unsigned int mode)
1546 {
1547 	struct parport_ip32_private * const priv = p->physport->private_data;
1548 	unsigned int residue;
1549 	unsigned int cnfga;
1550 
1551 	/* FIXME - We are missing one byte if the printer is off-line.  I
1552 	 * don't know how to detect this.  It looks that the full bit is not
1553 	 * always reliable.  For the moment, the problem is avoided in most
1554 	 * cases by testing for BUSY in parport_ip32_compat_write_data().
1555 	 */
1556 	if (parport_ip32_read_econtrol(p) & ECR_F_EMPTY)
1557 		residue = 0;
1558 	else {
1559 		pr_debug1(PPIP32 "%s: FIFO is stuck\n", p->name);
1560 
1561 		/* Stop all transfers.
1562 		 *
1563 		 * Microsoft's document instructs to drive DCR_STROBE to 0,
1564 		 * but it doesn't work (at least in Compatibility mode, not
1565 		 * tested in ECP mode).  Switching directly to Test mode (as
1566 		 * in parport_pc) is not an option: it does confuse the port,
1567 		 * ECP service interrupts are no more working after that.  A
1568 		 * hard reset is then needed to revert to a sane state.
1569 		 *
1570 		 * Let's hope that the FIFO is really stuck and that the
1571 		 * peripheral doesn't wake up now.
1572 		 */
1573 		parport_ip32_frob_control(p, DCR_STROBE, 0);
1574 
1575 		/* Fill up FIFO */
1576 		for (residue = priv->fifo_depth; residue > 0; residue--) {
1577 			if (parport_ip32_read_econtrol(p) & ECR_F_FULL)
1578 				break;
1579 			writeb(0x00, priv->regs.fifo);
1580 		}
1581 	}
1582 	if (residue)
1583 		pr_debug1(PPIP32 "%s: %d PWord%s left in FIFO\n",
1584 			  p->name, residue,
1585 			  (residue == 1) ? " was" : "s were");
1586 
1587 	/* Now reset the FIFO */
1588 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1589 
1590 	/* Host recovery for ECP mode */
1591 	if (mode == ECR_MODE_ECP) {
1592 		parport_ip32_data_reverse(p);
1593 		parport_ip32_frob_control(p, DCR_nINIT, 0);
1594 		if (parport_wait_peripheral(p, DSR_PERROR, 0))
1595 			pr_debug1(PPIP32 "%s: PEerror timeout 1 in %s\n",
1596 				  p->name, __func__);
1597 		parport_ip32_frob_control(p, DCR_STROBE, DCR_STROBE);
1598 		parport_ip32_frob_control(p, DCR_nINIT, DCR_nINIT);
1599 		if (parport_wait_peripheral(p, DSR_PERROR, DSR_PERROR))
1600 			pr_debug1(PPIP32 "%s: PEerror timeout 2 in %s\n",
1601 				  p->name, __func__);
1602 	}
1603 
1604 	/* Adjust residue if needed */
1605 	parport_ip32_set_mode(p, ECR_MODE_CFG);
1606 	cnfga = readb(priv->regs.cnfgA);
1607 	if (!(cnfga & CNFGA_nBYTEINTRANS)) {
1608 		pr_debug1(PPIP32 "%s: cnfgA contains 0x%02x\n",
1609 			  p->name, cnfga);
1610 		pr_debug1(PPIP32 "%s: Accounting for extra byte\n",
1611 			  p->name);
1612 		residue++;
1613 	}
1614 
1615 	/* Don't care about partial PWords since we do not support
1616 	 * PWord != 1 byte. */
1617 
1618 	/* Back to forward PS2 mode. */
1619 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1620 	parport_ip32_data_forward(p);
1621 
1622 	return residue;
1623 }
1624 
1625 /**
1626  * parport_ip32_compat_write_data - write a block of data in SPP mode
1627  * @p:		pointer to &struct parport
1628  * @buf:	buffer of data to write
1629  * @len:	length of buffer @buf
1630  * @flags:	ignored
1631  */
1632 static size_t parport_ip32_compat_write_data(struct parport *p,
1633 					     const void *buf, size_t len,
1634 					     int flags)
1635 {
1636 	static unsigned int ready_before = 1;
1637 	struct parport_ip32_private * const priv = p->physport->private_data;
1638 	struct parport * const physport = p->physport;
1639 	size_t written = 0;
1640 
1641 	/* Special case: a timeout of zero means we cannot call schedule().
1642 	 * Also if O_NONBLOCK is set then use the default implementation. */
1643 	if (physport->cad->timeout <= PARPORT_INACTIVITY_O_NONBLOCK)
1644 		return parport_ieee1284_write_compat(p, buf, len, flags);
1645 
1646 	/* Reset FIFO, go in forward mode, and disable ackIntEn */
1647 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1648 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
1649 	parport_ip32_data_forward(p);
1650 	parport_ip32_disable_irq(p);
1651 	parport_ip32_set_mode(p, ECR_MODE_PPF);
1652 	physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;
1653 
1654 	/* Wait for peripheral to become ready */
1655 	if (parport_wait_peripheral(p, DSR_nBUSY | DSR_nFAULT,
1656 				       DSR_nBUSY | DSR_nFAULT)) {
1657 		/* Avoid to flood the logs */
1658 		if (ready_before)
1659 			printk(KERN_INFO PPIP32 "%s: not ready in %s\n",
1660 			       p->name, __func__);
1661 		ready_before = 0;
1662 		goto stop;
1663 	}
1664 	ready_before = 1;
1665 
1666 	written = parport_ip32_fifo_write_block(p, buf, len);
1667 
1668 	/* Wait FIFO to empty.  Timeout is proportional to FIFO_depth.  */
1669 	parport_ip32_drain_fifo(p, physport->cad->timeout * priv->fifo_depth);
1670 
1671 	/* Check for a potential residue */
1672 	written -= parport_ip32_get_fifo_residue(p, ECR_MODE_PPF);
1673 
1674 	/* Then, wait for BUSY to get low. */
1675 	if (parport_wait_peripheral(p, DSR_nBUSY, DSR_nBUSY))
1676 		printk(KERN_DEBUG PPIP32 "%s: BUSY timeout in %s\n",
1677 		       p->name, __func__);
1678 
1679 stop:
1680 	/* Reset FIFO */
1681 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1682 	physport->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
1683 
1684 	return written;
1685 }
1686 
1687 /*
1688  * FIXME - Insert here parport_ip32_ecp_read_data().
1689  */
1690 
1691 /**
1692  * parport_ip32_ecp_write_data - write a block of data in ECP mode
1693  * @p:		pointer to &struct parport
1694  * @buf:	buffer of data to write
1695  * @len:	length of buffer @buf
1696  * @flags:	ignored
1697  */
1698 static size_t parport_ip32_ecp_write_data(struct parport *p,
1699 					  const void *buf, size_t len,
1700 					  int flags)
1701 {
1702 	static unsigned int ready_before = 1;
1703 	struct parport_ip32_private * const priv = p->physport->private_data;
1704 	struct parport * const physport = p->physport;
1705 	size_t written = 0;
1706 
1707 	/* Special case: a timeout of zero means we cannot call schedule().
1708 	 * Also if O_NONBLOCK is set then use the default implementation. */
1709 	if (physport->cad->timeout <= PARPORT_INACTIVITY_O_NONBLOCK)
1710 		return parport_ieee1284_ecp_write_data(p, buf, len, flags);
1711 
1712 	/* Negotiate to forward mode if necessary. */
1713 	if (physport->ieee1284.phase != IEEE1284_PH_FWD_IDLE) {
1714 		/* Event 47: Set nInit high. */
1715 		parport_ip32_frob_control(p, DCR_nINIT | DCR_AUTOFD,
1716 					     DCR_nINIT | DCR_AUTOFD);
1717 
1718 		/* Event 49: PError goes high. */
1719 		if (parport_wait_peripheral(p, DSR_PERROR, DSR_PERROR)) {
1720 			printk(KERN_DEBUG PPIP32 "%s: PError timeout in %s",
1721 			       p->name, __func__);
1722 			physport->ieee1284.phase = IEEE1284_PH_ECP_DIR_UNKNOWN;
1723 			return 0;
1724 		}
1725 	}
1726 
1727 	/* Reset FIFO, go in forward mode, and disable ackIntEn */
1728 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1729 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
1730 	parport_ip32_data_forward(p);
1731 	parport_ip32_disable_irq(p);
1732 	parport_ip32_set_mode(p, ECR_MODE_ECP);
1733 	physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;
1734 
1735 	/* Wait for peripheral to become ready */
1736 	if (parport_wait_peripheral(p, DSR_nBUSY | DSR_nFAULT,
1737 				       DSR_nBUSY | DSR_nFAULT)) {
1738 		/* Avoid to flood the logs */
1739 		if (ready_before)
1740 			printk(KERN_INFO PPIP32 "%s: not ready in %s\n",
1741 			       p->name, __func__);
1742 		ready_before = 0;
1743 		goto stop;
1744 	}
1745 	ready_before = 1;
1746 
1747 	written = parport_ip32_fifo_write_block(p, buf, len);
1748 
1749 	/* Wait FIFO to empty.  Timeout is proportional to FIFO_depth.  */
1750 	parport_ip32_drain_fifo(p, physport->cad->timeout * priv->fifo_depth);
1751 
1752 	/* Check for a potential residue */
1753 	written -= parport_ip32_get_fifo_residue(p, ECR_MODE_ECP);
1754 
1755 	/* Then, wait for BUSY to get low. */
1756 	if (parport_wait_peripheral(p, DSR_nBUSY, DSR_nBUSY))
1757 		printk(KERN_DEBUG PPIP32 "%s: BUSY timeout in %s\n",
1758 		       p->name, __func__);
1759 
1760 stop:
1761 	/* Reset FIFO */
1762 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1763 	physport->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
1764 
1765 	return written;
1766 }
1767 
1768 /*
1769  * FIXME - Insert here parport_ip32_ecp_write_addr().
1770  */
1771 
1772 /*--- Default parport operations ---------------------------------------*/
1773 
1774 static const struct parport_operations parport_ip32_ops __initconst = {
1775 	.write_data		= parport_ip32_write_data,
1776 	.read_data		= parport_ip32_read_data,
1777 
1778 	.write_control		= parport_ip32_write_control,
1779 	.read_control		= parport_ip32_read_control,
1780 	.frob_control		= parport_ip32_frob_control,
1781 
1782 	.read_status		= parport_ip32_read_status,
1783 
1784 	.enable_irq		= parport_ip32_enable_irq,
1785 	.disable_irq		= parport_ip32_disable_irq,
1786 
1787 	.data_forward		= parport_ip32_data_forward,
1788 	.data_reverse		= parport_ip32_data_reverse,
1789 
1790 	.init_state		= parport_ip32_init_state,
1791 	.save_state		= parport_ip32_save_state,
1792 	.restore_state		= parport_ip32_restore_state,
1793 
1794 	.epp_write_data		= parport_ieee1284_epp_write_data,
1795 	.epp_read_data		= parport_ieee1284_epp_read_data,
1796 	.epp_write_addr		= parport_ieee1284_epp_write_addr,
1797 	.epp_read_addr		= parport_ieee1284_epp_read_addr,
1798 
1799 	.ecp_write_data		= parport_ieee1284_ecp_write_data,
1800 	.ecp_read_data		= parport_ieee1284_ecp_read_data,
1801 	.ecp_write_addr		= parport_ieee1284_ecp_write_addr,
1802 
1803 	.compat_write_data	= parport_ieee1284_write_compat,
1804 	.nibble_read_data	= parport_ieee1284_read_nibble,
1805 	.byte_read_data		= parport_ieee1284_read_byte,
1806 
1807 	.owner			= THIS_MODULE,
1808 };
1809 
1810 /*--- Device detection -------------------------------------------------*/
1811 
1812 /**
1813  * parport_ip32_ecp_supported - check for an ECP port
1814  * @p:		pointer to the &parport structure
1815  *
1816  * Returns 1 if an ECP port is found, and 0 otherwise.  This function actually
1817  * checks if an Extended Control Register seems to be present.  On successful
1818  * return, the port is placed in SPP mode.
1819  */
1820 static __init unsigned int parport_ip32_ecp_supported(struct parport *p)
1821 {
1822 	struct parport_ip32_private * const priv = p->physport->private_data;
1823 	unsigned int ecr;
1824 
1825 	ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
1826 	writeb(ecr, priv->regs.ecr);
1827 	if (readb(priv->regs.ecr) != (ecr | ECR_F_EMPTY))
1828 		goto fail;
1829 
1830 	pr_probe(p, "Found working ECR register\n");
1831 	parport_ip32_set_mode(p, ECR_MODE_SPP);
1832 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
1833 	return 1;
1834 
1835 fail:
1836 	pr_probe(p, "ECR register not found\n");
1837 	return 0;
1838 }
1839 
1840 /**
1841  * parport_ip32_fifo_supported - check for FIFO parameters
1842  * @p:		pointer to the &parport structure
1843  *
1844  * Check for FIFO parameters of an Extended Capabilities Port.  Returns 1 on
1845  * success, and 0 otherwise.  Adjust FIFO parameters in the parport structure.
1846  * On return, the port is placed in SPP mode.
1847  */
1848 static __init unsigned int parport_ip32_fifo_supported(struct parport *p)
1849 {
1850 	struct parport_ip32_private * const priv = p->physport->private_data;
1851 	unsigned int configa, configb;
1852 	unsigned int pword;
1853 	unsigned int i;
1854 
1855 	/* Configuration mode */
1856 	parport_ip32_set_mode(p, ECR_MODE_CFG);
1857 	configa = readb(priv->regs.cnfgA);
1858 	configb = readb(priv->regs.cnfgB);
1859 
1860 	/* Find out PWord size */
1861 	switch (configa & CNFGA_ID_MASK) {
1862 	case CNFGA_ID_8:
1863 		pword = 1;
1864 		break;
1865 	case CNFGA_ID_16:
1866 		pword = 2;
1867 		break;
1868 	case CNFGA_ID_32:
1869 		pword = 4;
1870 		break;
1871 	default:
1872 		pr_probe(p, "Unknown implementation ID: 0x%0x\n",
1873 			 (configa & CNFGA_ID_MASK) >> CNFGA_ID_SHIFT);
1874 		goto fail;
1875 		break;
1876 	}
1877 	if (pword != 1) {
1878 		pr_probe(p, "Unsupported PWord size: %u\n", pword);
1879 		goto fail;
1880 	}
1881 	priv->pword = pword;
1882 	pr_probe(p, "PWord is %u bits\n", 8 * priv->pword);
1883 
1884 	/* Check for compression support */
1885 	writeb(configb | CNFGB_COMPRESS, priv->regs.cnfgB);
1886 	if (readb(priv->regs.cnfgB) & CNFGB_COMPRESS)
1887 		pr_probe(p, "Hardware compression detected (unsupported)\n");
1888 	writeb(configb & ~CNFGB_COMPRESS, priv->regs.cnfgB);
1889 
1890 	/* Reset FIFO and go in test mode (no interrupt, no DMA) */
1891 	parport_ip32_set_mode(p, ECR_MODE_TST);
1892 
1893 	/* FIFO must be empty now */
1894 	if (!(readb(priv->regs.ecr) & ECR_F_EMPTY)) {
1895 		pr_probe(p, "FIFO not reset\n");
1896 		goto fail;
1897 	}
1898 
1899 	/* Find out FIFO depth. */
1900 	priv->fifo_depth = 0;
1901 	for (i = 0; i < 1024; i++) {
1902 		if (readb(priv->regs.ecr) & ECR_F_FULL) {
1903 			/* FIFO full */
1904 			priv->fifo_depth = i;
1905 			break;
1906 		}
1907 		writeb((u8)i, priv->regs.fifo);
1908 	}
1909 	if (i >= 1024) {
1910 		pr_probe(p, "Can't fill FIFO\n");
1911 		goto fail;
1912 	}
1913 	if (!priv->fifo_depth) {
1914 		pr_probe(p, "Can't get FIFO depth\n");
1915 		goto fail;
1916 	}
1917 	pr_probe(p, "FIFO is %u PWords deep\n", priv->fifo_depth);
1918 
1919 	/* Enable interrupts */
1920 	parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
1921 
1922 	/* Find out writeIntrThreshold: number of PWords we know we can write
1923 	 * if we get an interrupt. */
1924 	priv->writeIntrThreshold = 0;
1925 	for (i = 0; i < priv->fifo_depth; i++) {
1926 		if (readb(priv->regs.fifo) != (u8)i) {
1927 			pr_probe(p, "Invalid data in FIFO\n");
1928 			goto fail;
1929 		}
1930 		if (!priv->writeIntrThreshold
1931 		    && readb(priv->regs.ecr) & ECR_SERVINTR)
1932 			/* writeIntrThreshold reached */
1933 			priv->writeIntrThreshold = i + 1;
1934 		if (i + 1 < priv->fifo_depth
1935 		    && readb(priv->regs.ecr) & ECR_F_EMPTY) {
1936 			/* FIFO empty before the last byte? */
1937 			pr_probe(p, "Data lost in FIFO\n");
1938 			goto fail;
1939 		}
1940 	}
1941 	if (!priv->writeIntrThreshold) {
1942 		pr_probe(p, "Can't get writeIntrThreshold\n");
1943 		goto fail;
1944 	}
1945 	pr_probe(p, "writeIntrThreshold is %u\n", priv->writeIntrThreshold);
1946 
1947 	/* FIFO must be empty now */
1948 	if (!(readb(priv->regs.ecr) & ECR_F_EMPTY)) {
1949 		pr_probe(p, "Can't empty FIFO\n");
1950 		goto fail;
1951 	}
1952 
1953 	/* Reset FIFO */
1954 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1955 	/* Set reverse direction (must be in PS2 mode) */
1956 	parport_ip32_data_reverse(p);
1957 	/* Test FIFO, no interrupt, no DMA */
1958 	parport_ip32_set_mode(p, ECR_MODE_TST);
1959 	/* Enable interrupts */
1960 	parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
1961 
1962 	/* Find out readIntrThreshold: number of PWords we can read if we get
1963 	 * an interrupt. */
1964 	priv->readIntrThreshold = 0;
1965 	for (i = 0; i < priv->fifo_depth; i++) {
1966 		writeb(0xaa, priv->regs.fifo);
1967 		if (readb(priv->regs.ecr) & ECR_SERVINTR) {
1968 			/* readIntrThreshold reached */
1969 			priv->readIntrThreshold = i + 1;
1970 			break;
1971 		}
1972 	}
1973 	if (!priv->readIntrThreshold) {
1974 		pr_probe(p, "Can't get readIntrThreshold\n");
1975 		goto fail;
1976 	}
1977 	pr_probe(p, "readIntrThreshold is %u\n", priv->readIntrThreshold);
1978 
1979 	/* Reset ECR */
1980 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1981 	parport_ip32_data_forward(p);
1982 	parport_ip32_set_mode(p, ECR_MODE_SPP);
1983 	return 1;
1984 
1985 fail:
1986 	priv->fifo_depth = 0;
1987 	parport_ip32_set_mode(p, ECR_MODE_SPP);
1988 	return 0;
1989 }
1990 
1991 /*--- Initialization code ----------------------------------------------*/
1992 
1993 /**
1994  * parport_ip32_make_isa_registers - compute (ISA) register addresses
1995  * @regs:	pointer to &struct parport_ip32_regs to fill
1996  * @base:	base address of standard and EPP registers
1997  * @base_hi:	base address of ECP registers
1998  * @regshift:	how much to shift register offset by
1999  *
2000  * Compute register addresses, according to the ISA standard.  The addresses
2001  * of the standard and EPP registers are computed from address @base.  The
2002  * addresses of the ECP registers are computed from address @base_hi.
2003  */
2004 static void __init
2005 parport_ip32_make_isa_registers(struct parport_ip32_regs *regs,
2006 				void __iomem *base, void __iomem *base_hi,
2007 				unsigned int regshift)
2008 {
2009 #define r_base(offset)    ((u8 __iomem *)base    + ((offset) << regshift))
2010 #define r_base_hi(offset) ((u8 __iomem *)base_hi + ((offset) << regshift))
2011 	*regs = (struct parport_ip32_regs){
2012 		.data		= r_base(0),
2013 		.dsr		= r_base(1),
2014 		.dcr		= r_base(2),
2015 		.eppAddr	= r_base(3),
2016 		.eppData0	= r_base(4),
2017 		.eppData1	= r_base(5),
2018 		.eppData2	= r_base(6),
2019 		.eppData3	= r_base(7),
2020 		.ecpAFifo	= r_base(0),
2021 		.fifo		= r_base_hi(0),
2022 		.cnfgA		= r_base_hi(0),
2023 		.cnfgB		= r_base_hi(1),
2024 		.ecr		= r_base_hi(2)
2025 	};
2026 #undef r_base_hi
2027 #undef r_base
2028 }
2029 
2030 /**
2031  * parport_ip32_probe_port - probe and register IP32 built-in parallel port
2032  *
2033  * Returns the new allocated &parport structure.  On error, an error code is
2034  * encoded in return value with the ERR_PTR function.
2035  */
2036 static __init struct parport *parport_ip32_probe_port(void)
2037 {
2038 	struct parport_ip32_regs regs;
2039 	struct parport_ip32_private *priv = NULL;
2040 	struct parport_operations *ops = NULL;
2041 	struct parport *p = NULL;
2042 	int err;
2043 
2044 	parport_ip32_make_isa_registers(&regs, &mace->isa.parallel,
2045 					&mace->isa.ecp1284, 8 /* regshift */);
2046 
2047 	ops = kmalloc(sizeof(struct parport_operations), GFP_KERNEL);
2048 	priv = kmalloc(sizeof(struct parport_ip32_private), GFP_KERNEL);
2049 	p = parport_register_port(0, PARPORT_IRQ_NONE, PARPORT_DMA_NONE, ops);
2050 	if (ops == NULL || priv == NULL || p == NULL) {
2051 		err = -ENOMEM;
2052 		goto fail;
2053 	}
2054 	p->base = MACE_BASE + offsetof(struct sgi_mace, isa.parallel);
2055 	p->base_hi = MACE_BASE + offsetof(struct sgi_mace, isa.ecp1284);
2056 	p->private_data = priv;
2057 
2058 	*ops = parport_ip32_ops;
2059 	*priv = (struct parport_ip32_private){
2060 		.regs			= regs,
2061 		.dcr_writable		= DCR_DIR | DCR_SELECT | DCR_nINIT |
2062 					  DCR_AUTOFD | DCR_STROBE,
2063 		.irq_mode		= PARPORT_IP32_IRQ_FWD,
2064 	};
2065 	init_completion(&priv->irq_complete);
2066 
2067 	/* Probe port. */
2068 	if (!parport_ip32_ecp_supported(p)) {
2069 		err = -ENODEV;
2070 		goto fail;
2071 	}
2072 	parport_ip32_dump_state(p, "begin init", 0);
2073 
2074 	/* We found what looks like a working ECR register.  Simply assume
2075 	 * that all modes are correctly supported.  Enable basic modes. */
2076 	p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
2077 	p->modes |= PARPORT_MODE_TRISTATE;
2078 
2079 	if (!parport_ip32_fifo_supported(p)) {
2080 		printk(KERN_WARNING PPIP32
2081 		       "%s: error: FIFO disabled\n", p->name);
2082 		/* Disable hardware modes depending on a working FIFO. */
2083 		features &= ~PARPORT_IP32_ENABLE_SPP;
2084 		features &= ~PARPORT_IP32_ENABLE_ECP;
2085 		/* DMA is not needed if FIFO is not supported.  */
2086 		features &= ~PARPORT_IP32_ENABLE_DMA;
2087 	}
2088 
2089 	/* Request IRQ */
2090 	if (features & PARPORT_IP32_ENABLE_IRQ) {
2091 		int irq = MACEISA_PARALLEL_IRQ;
2092 		if (request_irq(irq, parport_ip32_interrupt, 0, p->name, p)) {
2093 			printk(KERN_WARNING PPIP32
2094 			       "%s: error: IRQ disabled\n", p->name);
2095 			/* DMA cannot work without interrupts. */
2096 			features &= ~PARPORT_IP32_ENABLE_DMA;
2097 		} else {
2098 			pr_probe(p, "Interrupt support enabled\n");
2099 			p->irq = irq;
2100 			priv->dcr_writable |= DCR_IRQ;
2101 		}
2102 	}
2103 
2104 	/* Allocate DMA resources */
2105 	if (features & PARPORT_IP32_ENABLE_DMA) {
2106 		if (parport_ip32_dma_register())
2107 			printk(KERN_WARNING PPIP32
2108 			       "%s: error: DMA disabled\n", p->name);
2109 		else {
2110 			pr_probe(p, "DMA support enabled\n");
2111 			p->dma = 0; /* arbitrary value != PARPORT_DMA_NONE */
2112 			p->modes |= PARPORT_MODE_DMA;
2113 		}
2114 	}
2115 
2116 	if (features & PARPORT_IP32_ENABLE_SPP) {
2117 		/* Enable compatibility FIFO mode */
2118 		p->ops->compat_write_data = parport_ip32_compat_write_data;
2119 		p->modes |= PARPORT_MODE_COMPAT;
2120 		pr_probe(p, "Hardware support for SPP mode enabled\n");
2121 	}
2122 	if (features & PARPORT_IP32_ENABLE_EPP) {
2123 		/* Set up access functions to use EPP hardware. */
2124 		p->ops->epp_read_data = parport_ip32_epp_read_data;
2125 		p->ops->epp_write_data = parport_ip32_epp_write_data;
2126 		p->ops->epp_read_addr = parport_ip32_epp_read_addr;
2127 		p->ops->epp_write_addr = parport_ip32_epp_write_addr;
2128 		p->modes |= PARPORT_MODE_EPP;
2129 		pr_probe(p, "Hardware support for EPP mode enabled\n");
2130 	}
2131 	if (features & PARPORT_IP32_ENABLE_ECP) {
2132 		/* Enable ECP FIFO mode */
2133 		p->ops->ecp_write_data = parport_ip32_ecp_write_data;
2134 		/* FIXME - not implemented */
2135 /*		p->ops->ecp_read_data  = parport_ip32_ecp_read_data; */
2136 /*		p->ops->ecp_write_addr = parport_ip32_ecp_write_addr; */
2137 		p->modes |= PARPORT_MODE_ECP;
2138 		pr_probe(p, "Hardware support for ECP mode enabled\n");
2139 	}
2140 
2141 	/* Initialize the port with sensible values */
2142 	parport_ip32_set_mode(p, ECR_MODE_PS2);
2143 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
2144 	parport_ip32_data_forward(p);
2145 	parport_ip32_disable_irq(p);
2146 	parport_ip32_write_data(p, 0x00);
2147 	parport_ip32_dump_state(p, "end init", 0);
2148 
2149 	/* Print out what we found */
2150 	printk(KERN_INFO "%s: SGI IP32 at 0x%lx (0x%lx)",
2151 	       p->name, p->base, p->base_hi);
2152 	if (p->irq != PARPORT_IRQ_NONE)
2153 		printk(", irq %d", p->irq);
2154 	printk(" [");
2155 #define printmode(x)	if (p->modes & PARPORT_MODE_##x)		\
2156 				printk("%s%s", f++ ? "," : "", #x)
2157 	{
2158 		unsigned int f = 0;
2159 		printmode(PCSPP);
2160 		printmode(TRISTATE);
2161 		printmode(COMPAT);
2162 		printmode(EPP);
2163 		printmode(ECP);
2164 		printmode(DMA);
2165 	}
2166 #undef printmode
2167 	printk("]\n");
2168 
2169 	parport_announce_port(p);
2170 	return p;
2171 
2172 fail:
2173 	if (p)
2174 		parport_put_port(p);
2175 	kfree(priv);
2176 	kfree(ops);
2177 	return ERR_PTR(err);
2178 }
2179 
2180 /**
2181  * parport_ip32_unregister_port - unregister a parallel port
2182  * @p:		pointer to the &struct parport
2183  *
2184  * Unregisters a parallel port and free previously allocated resources
2185  * (memory, IRQ, ...).
2186  */
2187 static __exit void parport_ip32_unregister_port(struct parport *p)
2188 {
2189 	struct parport_ip32_private * const priv = p->physport->private_data;
2190 	struct parport_operations *ops = p->ops;
2191 
2192 	parport_remove_port(p);
2193 	if (p->modes & PARPORT_MODE_DMA)
2194 		parport_ip32_dma_unregister();
2195 	if (p->irq != PARPORT_IRQ_NONE)
2196 		free_irq(p->irq, p);
2197 	parport_put_port(p);
2198 	kfree(priv);
2199 	kfree(ops);
2200 }
2201 
2202 /**
2203  * parport_ip32_init - module initialization function
2204  */
2205 static int __init parport_ip32_init(void)
2206 {
2207 	pr_info(PPIP32 "SGI IP32 built-in parallel port driver v0.6\n");
2208 	this_port = parport_ip32_probe_port();
2209 	return PTR_ERR_OR_ZERO(this_port);
2210 }
2211 
2212 /**
2213  * parport_ip32_exit - module termination function
2214  */
2215 static void __exit parport_ip32_exit(void)
2216 {
2217 	parport_ip32_unregister_port(this_port);
2218 }
2219 
2220 /*--- Module stuff -----------------------------------------------------*/
2221 
2222 MODULE_AUTHOR("Arnaud Giersch <arnaud.giersch@free.fr>");
2223 MODULE_DESCRIPTION("SGI IP32 built-in parallel port driver");
2224 MODULE_LICENSE("GPL");
2225 MODULE_VERSION("0.6");		/* update in parport_ip32_init() too */
2226 
2227 module_init(parport_ip32_init);
2228 module_exit(parport_ip32_exit);
2229 
2230 module_param(verbose_probing, bool, S_IRUGO);
2231 MODULE_PARM_DESC(verbose_probing, "Log chit-chat during initialization");
2232 
2233 module_param(features, uint, S_IRUGO);
2234 MODULE_PARM_DESC(features,
2235 		 "Bit mask of features to enable"
2236 		 ", bit 0: IRQ support"
2237 		 ", bit 1: DMA support"
2238 		 ", bit 2: hardware SPP mode"
2239 		 ", bit 3: hardware EPP mode"
2240 		 ", bit 4: hardware ECP mode");
2241 
2242 /*--- Inform (X)Emacs about preferred coding style ---------------------*/
2243 /*
2244  * Local Variables:
2245  * mode: c
2246  * c-file-style: "linux"
2247  * indent-tabs-mode: t
2248  * tab-width: 8
2249  * fill-column: 78
2250  * ispell-local-dictionary: "american"
2251  * End:
2252  */
2253