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 	switch (irq_mode) {
782 	case PARPORT_IP32_IRQ_FWD:
783 		parport_generic_irq(irq, p);
784 		break;
785 	case PARPORT_IP32_IRQ_HERE:
786 		parport_ip32_wakeup(p);
787 		break;
788 	}
789 	return IRQ_HANDLED;
790 }
791 
792 /*--- Some utility function to manipulate ECR register -----------------*/
793 
794 /**
795  * parport_ip32_read_econtrol - read contents of the ECR register
796  * @p:		pointer to &struct parport
797  */
798 static inline unsigned int parport_ip32_read_econtrol(struct parport *p)
799 {
800 	struct parport_ip32_private * const priv = p->physport->private_data;
801 	return readb(priv->regs.ecr);
802 }
803 
804 /**
805  * parport_ip32_write_econtrol - write new contents to the ECR register
806  * @p:		pointer to &struct parport
807  * @c:		new value to write
808  */
809 static inline void parport_ip32_write_econtrol(struct parport *p,
810 					       unsigned int c)
811 {
812 	struct parport_ip32_private * const priv = p->physport->private_data;
813 	writeb(c, priv->regs.ecr);
814 }
815 
816 /**
817  * parport_ip32_frob_econtrol - change bits from the ECR register
818  * @p:		pointer to &struct parport
819  * @mask:	bit mask of bits to change
820  * @val:	new value for changed bits
821  *
822  * Read from the ECR, mask out the bits in @mask, exclusive-or with the bits
823  * in @val, and write the result to the ECR.
824  */
825 static inline void parport_ip32_frob_econtrol(struct parport *p,
826 					      unsigned int mask,
827 					      unsigned int val)
828 {
829 	unsigned int c;
830 	c = (parport_ip32_read_econtrol(p) & ~mask) ^ val;
831 	parport_ip32_write_econtrol(p, c);
832 }
833 
834 /**
835  * parport_ip32_set_mode - change mode of ECP port
836  * @p:		pointer to &struct parport
837  * @mode:	new mode to write in ECR
838  *
839  * ECR is reset in a sane state (interrupts and DMA disabled), and placed in
840  * mode @mode.  Go through PS2 mode if needed.
841  */
842 static void parport_ip32_set_mode(struct parport *p, unsigned int mode)
843 {
844 	unsigned int omode;
845 
846 	mode &= ECR_MODE_MASK;
847 	omode = parport_ip32_read_econtrol(p) & ECR_MODE_MASK;
848 
849 	if (!(mode == ECR_MODE_SPP || mode == ECR_MODE_PS2
850 	      || omode == ECR_MODE_SPP || omode == ECR_MODE_PS2)) {
851 		/* We have to go through PS2 mode */
852 		unsigned int ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
853 		parport_ip32_write_econtrol(p, ecr);
854 	}
855 	parport_ip32_write_econtrol(p, mode | ECR_nERRINTR | ECR_SERVINTR);
856 }
857 
858 /*--- Basic functions needed for parport -------------------------------*/
859 
860 /**
861  * parport_ip32_read_data - return current contents of the DATA register
862  * @p:		pointer to &struct parport
863  */
864 static inline unsigned char parport_ip32_read_data(struct parport *p)
865 {
866 	struct parport_ip32_private * const priv = p->physport->private_data;
867 	return readb(priv->regs.data);
868 }
869 
870 /**
871  * parport_ip32_write_data - set new contents for the DATA register
872  * @p:		pointer to &struct parport
873  * @d:		new value to write
874  */
875 static inline void parport_ip32_write_data(struct parport *p, unsigned char d)
876 {
877 	struct parport_ip32_private * const priv = p->physport->private_data;
878 	writeb(d, priv->regs.data);
879 }
880 
881 /**
882  * parport_ip32_read_status - return current contents of the DSR register
883  * @p:		pointer to &struct parport
884  */
885 static inline unsigned char parport_ip32_read_status(struct parport *p)
886 {
887 	struct parport_ip32_private * const priv = p->physport->private_data;
888 	return readb(priv->regs.dsr);
889 }
890 
891 /**
892  * __parport_ip32_read_control - return cached contents of the DCR register
893  * @p:		pointer to &struct parport
894  */
895 static inline unsigned int __parport_ip32_read_control(struct parport *p)
896 {
897 	struct parport_ip32_private * const priv = p->physport->private_data;
898 	return priv->dcr_cache; /* use soft copy */
899 }
900 
901 /**
902  * __parport_ip32_write_control - set new contents for the DCR register
903  * @p:		pointer to &struct parport
904  * @c:		new value to write
905  */
906 static inline void __parport_ip32_write_control(struct parport *p,
907 						unsigned int c)
908 {
909 	struct parport_ip32_private * const priv = p->physport->private_data;
910 	CHECK_EXTRA_BITS(p, c, priv->dcr_writable);
911 	c &= priv->dcr_writable; /* only writable bits */
912 	writeb(c, priv->regs.dcr);
913 	priv->dcr_cache = c;		/* update soft copy */
914 }
915 
916 /**
917  * __parport_ip32_frob_control - change bits from the DCR register
918  * @p:		pointer to &struct parport
919  * @mask:	bit mask of bits to change
920  * @val:	new value for changed bits
921  *
922  * This is equivalent to read from the DCR, mask out the bits in @mask,
923  * exclusive-or with the bits in @val, and write the result to the DCR.
924  * Actually, the cached contents of the DCR is used.
925  */
926 static inline void __parport_ip32_frob_control(struct parport *p,
927 					       unsigned int mask,
928 					       unsigned int val)
929 {
930 	unsigned int c;
931 	c = (__parport_ip32_read_control(p) & ~mask) ^ val;
932 	__parport_ip32_write_control(p, c);
933 }
934 
935 /**
936  * parport_ip32_read_control - return cached contents of the DCR register
937  * @p:		pointer to &struct parport
938  *
939  * The return value is masked so as to only return the value of %DCR_STROBE,
940  * %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
941  */
942 static inline unsigned char parport_ip32_read_control(struct parport *p)
943 {
944 	const unsigned int rm =
945 		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
946 	return __parport_ip32_read_control(p) & rm;
947 }
948 
949 /**
950  * parport_ip32_write_control - set new contents for the DCR register
951  * @p:		pointer to &struct parport
952  * @c:		new value to write
953  *
954  * The value is masked so as to only change the value of %DCR_STROBE,
955  * %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
956  */
957 static inline void parport_ip32_write_control(struct parport *p,
958 					      unsigned char c)
959 {
960 	const unsigned int wm =
961 		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
962 	CHECK_EXTRA_BITS(p, c, wm);
963 	__parport_ip32_frob_control(p, wm, c & wm);
964 }
965 
966 /**
967  * parport_ip32_frob_control - change bits from the DCR register
968  * @p:		pointer to &struct parport
969  * @mask:	bit mask of bits to change
970  * @val:	new value for changed bits
971  *
972  * This differs from __parport_ip32_frob_control() in that it only allows to
973  * change the value of %DCR_STROBE, %DCR_AUTOFD, %DCR_nINIT, and %DCR_SELECT.
974  */
975 static inline unsigned char parport_ip32_frob_control(struct parport *p,
976 						      unsigned char mask,
977 						      unsigned char val)
978 {
979 	const unsigned int wm =
980 		DCR_STROBE | DCR_AUTOFD | DCR_nINIT | DCR_SELECT;
981 	CHECK_EXTRA_BITS(p, mask, wm);
982 	CHECK_EXTRA_BITS(p, val, wm);
983 	__parport_ip32_frob_control(p, mask & wm, val & wm);
984 	return parport_ip32_read_control(p);
985 }
986 
987 /**
988  * parport_ip32_disable_irq - disable interrupts on the rising edge of nACK
989  * @p:		pointer to &struct parport
990  */
991 static inline void parport_ip32_disable_irq(struct parport *p)
992 {
993 	__parport_ip32_frob_control(p, DCR_IRQ, 0);
994 }
995 
996 /**
997  * parport_ip32_enable_irq - enable interrupts on the rising edge of nACK
998  * @p:		pointer to &struct parport
999  */
1000 static inline void parport_ip32_enable_irq(struct parport *p)
1001 {
1002 	__parport_ip32_frob_control(p, DCR_IRQ, DCR_IRQ);
1003 }
1004 
1005 /**
1006  * parport_ip32_data_forward - enable host-to-peripheral communications
1007  * @p:		pointer to &struct parport
1008  *
1009  * Enable the data line drivers, for 8-bit host-to-peripheral communications.
1010  */
1011 static inline void parport_ip32_data_forward(struct parport *p)
1012 {
1013 	__parport_ip32_frob_control(p, DCR_DIR, 0);
1014 }
1015 
1016 /**
1017  * parport_ip32_data_reverse - enable peripheral-to-host communications
1018  * @p:		pointer to &struct parport
1019  *
1020  * Place the data bus in a high impedance state, if @p->modes has the
1021  * PARPORT_MODE_TRISTATE bit set.
1022  */
1023 static inline void parport_ip32_data_reverse(struct parport *p)
1024 {
1025 	__parport_ip32_frob_control(p, DCR_DIR, DCR_DIR);
1026 }
1027 
1028 /**
1029  * parport_ip32_init_state - for core parport code
1030  * @dev:	pointer to &struct pardevice
1031  * @s:		pointer to &struct parport_state to initialize
1032  */
1033 static void parport_ip32_init_state(struct pardevice *dev,
1034 				    struct parport_state *s)
1035 {
1036 	s->u.ip32.dcr = DCR_SELECT | DCR_nINIT;
1037 	s->u.ip32.ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
1038 }
1039 
1040 /**
1041  * parport_ip32_save_state - for core parport code
1042  * @p:		pointer to &struct parport
1043  * @s:		pointer to &struct parport_state to save state to
1044  */
1045 static void parport_ip32_save_state(struct parport *p,
1046 				    struct parport_state *s)
1047 {
1048 	s->u.ip32.dcr = __parport_ip32_read_control(p);
1049 	s->u.ip32.ecr = parport_ip32_read_econtrol(p);
1050 }
1051 
1052 /**
1053  * parport_ip32_restore_state - for core parport code
1054  * @p:		pointer to &struct parport
1055  * @s:		pointer to &struct parport_state to restore state from
1056  */
1057 static void parport_ip32_restore_state(struct parport *p,
1058 				       struct parport_state *s)
1059 {
1060 	parport_ip32_set_mode(p, s->u.ip32.ecr & ECR_MODE_MASK);
1061 	parport_ip32_write_econtrol(p, s->u.ip32.ecr);
1062 	__parport_ip32_write_control(p, s->u.ip32.dcr);
1063 }
1064 
1065 /*--- EPP mode functions -----------------------------------------------*/
1066 
1067 /**
1068  * parport_ip32_clear_epp_timeout - clear Timeout bit in EPP mode
1069  * @p:		pointer to &struct parport
1070  *
1071  * Returns 1 if the Timeout bit is clear, and 0 otherwise.
1072  */
1073 static unsigned int parport_ip32_clear_epp_timeout(struct parport *p)
1074 {
1075 	struct parport_ip32_private * const priv = p->physport->private_data;
1076 	unsigned int cleared;
1077 
1078 	if (!(parport_ip32_read_status(p) & DSR_TIMEOUT))
1079 		cleared = 1;
1080 	else {
1081 		unsigned int r;
1082 		/* To clear timeout some chips require double read */
1083 		parport_ip32_read_status(p);
1084 		r = parport_ip32_read_status(p);
1085 		/* Some reset by writing 1 */
1086 		writeb(r | DSR_TIMEOUT, priv->regs.dsr);
1087 		/* Others by writing 0 */
1088 		writeb(r & ~DSR_TIMEOUT, priv->regs.dsr);
1089 
1090 		r = parport_ip32_read_status(p);
1091 		cleared = !(r & DSR_TIMEOUT);
1092 	}
1093 
1094 	pr_trace(p, "(): %s", cleared ? "cleared" : "failed");
1095 	return cleared;
1096 }
1097 
1098 /**
1099  * parport_ip32_epp_read - generic EPP read function
1100  * @eppreg:	I/O register to read from
1101  * @p:		pointer to &struct parport
1102  * @buf:	buffer to store read data
1103  * @len:	length of buffer @buf
1104  * @flags:	may be PARPORT_EPP_FAST
1105  */
1106 static size_t parport_ip32_epp_read(void __iomem *eppreg,
1107 				    struct parport *p, void *buf,
1108 				    size_t len, int flags)
1109 {
1110 	struct parport_ip32_private * const priv = p->physport->private_data;
1111 	size_t got;
1112 	parport_ip32_set_mode(p, ECR_MODE_EPP);
1113 	parport_ip32_data_reverse(p);
1114 	parport_ip32_write_control(p, DCR_nINIT);
1115 	if ((flags & PARPORT_EPP_FAST) && (len > 1)) {
1116 		readsb(eppreg, buf, len);
1117 		if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1118 			parport_ip32_clear_epp_timeout(p);
1119 			return -EIO;
1120 		}
1121 		got = len;
1122 	} else {
1123 		u8 *bufp = buf;
1124 		for (got = 0; got < len; got++) {
1125 			*bufp++ = readb(eppreg);
1126 			if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1127 				parport_ip32_clear_epp_timeout(p);
1128 				break;
1129 			}
1130 		}
1131 	}
1132 	parport_ip32_data_forward(p);
1133 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1134 	return got;
1135 }
1136 
1137 /**
1138  * parport_ip32_epp_write - generic EPP write function
1139  * @eppreg:	I/O register to write to
1140  * @p:		pointer to &struct parport
1141  * @buf:	buffer of data to write
1142  * @len:	length of buffer @buf
1143  * @flags:	may be PARPORT_EPP_FAST
1144  */
1145 static size_t parport_ip32_epp_write(void __iomem *eppreg,
1146 				     struct parport *p, const void *buf,
1147 				     size_t len, int flags)
1148 {
1149 	struct parport_ip32_private * const priv = p->physport->private_data;
1150 	size_t written;
1151 	parport_ip32_set_mode(p, ECR_MODE_EPP);
1152 	parport_ip32_data_forward(p);
1153 	parport_ip32_write_control(p, DCR_nINIT);
1154 	if ((flags & PARPORT_EPP_FAST) && (len > 1)) {
1155 		writesb(eppreg, buf, len);
1156 		if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1157 			parport_ip32_clear_epp_timeout(p);
1158 			return -EIO;
1159 		}
1160 		written = len;
1161 	} else {
1162 		const u8 *bufp = buf;
1163 		for (written = 0; written < len; written++) {
1164 			writeb(*bufp++, eppreg);
1165 			if (readb(priv->regs.dsr) & DSR_TIMEOUT) {
1166 				parport_ip32_clear_epp_timeout(p);
1167 				break;
1168 			}
1169 		}
1170 	}
1171 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1172 	return written;
1173 }
1174 
1175 /**
1176  * parport_ip32_epp_read_data - read a block of data in EPP mode
1177  * @p:		pointer to &struct parport
1178  * @buf:	buffer to store read data
1179  * @len:	length of buffer @buf
1180  * @flags:	may be PARPORT_EPP_FAST
1181  */
1182 static size_t parport_ip32_epp_read_data(struct parport *p, void *buf,
1183 					 size_t len, int flags)
1184 {
1185 	struct parport_ip32_private * const priv = p->physport->private_data;
1186 	return parport_ip32_epp_read(priv->regs.eppData0, p, buf, len, flags);
1187 }
1188 
1189 /**
1190  * parport_ip32_epp_write_data - write a block of data in EPP mode
1191  * @p:		pointer to &struct parport
1192  * @buf:	buffer of data to write
1193  * @len:	length of buffer @buf
1194  * @flags:	may be PARPORT_EPP_FAST
1195  */
1196 static size_t parport_ip32_epp_write_data(struct parport *p, const void *buf,
1197 					  size_t len, int flags)
1198 {
1199 	struct parport_ip32_private * const priv = p->physport->private_data;
1200 	return parport_ip32_epp_write(priv->regs.eppData0, p, buf, len, flags);
1201 }
1202 
1203 /**
1204  * parport_ip32_epp_read_addr - read a block of addresses in EPP mode
1205  * @p:		pointer to &struct parport
1206  * @buf:	buffer to store read data
1207  * @len:	length of buffer @buf
1208  * @flags:	may be PARPORT_EPP_FAST
1209  */
1210 static size_t parport_ip32_epp_read_addr(struct parport *p, void *buf,
1211 					 size_t len, int flags)
1212 {
1213 	struct parport_ip32_private * const priv = p->physport->private_data;
1214 	return parport_ip32_epp_read(priv->regs.eppAddr, p, buf, len, flags);
1215 }
1216 
1217 /**
1218  * parport_ip32_epp_write_addr - write a block of addresses in EPP mode
1219  * @p:		pointer to &struct parport
1220  * @buf:	buffer of data to write
1221  * @len:	length of buffer @buf
1222  * @flags:	may be PARPORT_EPP_FAST
1223  */
1224 static size_t parport_ip32_epp_write_addr(struct parport *p, const void *buf,
1225 					  size_t len, int flags)
1226 {
1227 	struct parport_ip32_private * const priv = p->physport->private_data;
1228 	return parport_ip32_epp_write(priv->regs.eppAddr, p, buf, len, flags);
1229 }
1230 
1231 /*--- ECP mode functions (FIFO) ----------------------------------------*/
1232 
1233 /**
1234  * parport_ip32_fifo_wait_break - check if the waiting function should return
1235  * @p:		pointer to &struct parport
1236  * @expire:	timeout expiring date, in jiffies
1237  *
1238  * parport_ip32_fifo_wait_break() checks if the waiting function should return
1239  * immediately or not.  The break conditions are:
1240  *	- expired timeout;
1241  *	- a pending signal;
1242  *	- nFault asserted low.
1243  * This function also calls cond_resched().
1244  */
1245 static unsigned int parport_ip32_fifo_wait_break(struct parport *p,
1246 						 unsigned long expire)
1247 {
1248 	cond_resched();
1249 	if (time_after(jiffies, expire)) {
1250 		pr_debug1(PPIP32 "%s: FIFO write timed out\n", p->name);
1251 		return 1;
1252 	}
1253 	if (signal_pending(current)) {
1254 		pr_debug1(PPIP32 "%s: Signal pending\n", p->name);
1255 		return 1;
1256 	}
1257 	if (!(parport_ip32_read_status(p) & DSR_nFAULT)) {
1258 		pr_debug1(PPIP32 "%s: nFault asserted low\n", p->name);
1259 		return 1;
1260 	}
1261 	return 0;
1262 }
1263 
1264 /**
1265  * parport_ip32_fwp_wait_polling - wait for FIFO to empty (polling)
1266  * @p:		pointer to &struct parport
1267  *
1268  * Returns the number of bytes that can safely be written in the FIFO.  A
1269  * return value of zero means that the calling function should terminate as
1270  * fast as possible.
1271  */
1272 static unsigned int parport_ip32_fwp_wait_polling(struct parport *p)
1273 {
1274 	struct parport_ip32_private * const priv = p->physport->private_data;
1275 	struct parport * const physport = p->physport;
1276 	unsigned long expire;
1277 	unsigned int count;
1278 	unsigned int ecr;
1279 
1280 	expire = jiffies + physport->cad->timeout;
1281 	count = 0;
1282 	while (1) {
1283 		if (parport_ip32_fifo_wait_break(p, expire))
1284 			break;
1285 
1286 		/* Check FIFO state.  We do nothing when the FIFO is nor full,
1287 		 * nor empty.  It appears that the FIFO full bit is not always
1288 		 * reliable, the FIFO state is sometimes wrongly reported, and
1289 		 * the chip gets confused if we give it another byte. */
1290 		ecr = parport_ip32_read_econtrol(p);
1291 		if (ecr & ECR_F_EMPTY) {
1292 			/* FIFO is empty, fill it up */
1293 			count = priv->fifo_depth;
1294 			break;
1295 		}
1296 
1297 		/* Wait a moment... */
1298 		udelay(FIFO_POLLING_INTERVAL);
1299 	} /* while (1) */
1300 
1301 	return count;
1302 }
1303 
1304 /**
1305  * parport_ip32_fwp_wait_interrupt - wait for FIFO to empty (interrupt-driven)
1306  * @p:		pointer to &struct parport
1307  *
1308  * Returns the number of bytes that can safely be written in the FIFO.  A
1309  * return value of zero means that the calling function should terminate as
1310  * fast as possible.
1311  */
1312 static unsigned int parport_ip32_fwp_wait_interrupt(struct parport *p)
1313 {
1314 	static unsigned int lost_interrupt = 0;
1315 	struct parport_ip32_private * const priv = p->physport->private_data;
1316 	struct parport * const physport = p->physport;
1317 	unsigned long nfault_timeout;
1318 	unsigned long expire;
1319 	unsigned int count;
1320 	unsigned int ecr;
1321 
1322 	nfault_timeout = min((unsigned long)physport->cad->timeout,
1323 			     msecs_to_jiffies(FIFO_NFAULT_TIMEOUT));
1324 	expire = jiffies + physport->cad->timeout;
1325 	count = 0;
1326 	while (1) {
1327 		if (parport_ip32_fifo_wait_break(p, expire))
1328 			break;
1329 
1330 		/* Initialize mutex used to take interrupts into account */
1331 		INIT_COMPLETION(priv->irq_complete);
1332 
1333 		/* Enable serviceIntr */
1334 		parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
1335 
1336 		/* Enabling serviceIntr while the FIFO is empty does not
1337 		 * always generate an interrupt, so check for emptiness
1338 		 * now. */
1339 		ecr = parport_ip32_read_econtrol(p);
1340 		if (!(ecr & ECR_F_EMPTY)) {
1341 			/* FIFO is not empty: wait for an interrupt or a
1342 			 * timeout to occur */
1343 			wait_for_completion_interruptible_timeout(
1344 				&priv->irq_complete, nfault_timeout);
1345 			ecr = parport_ip32_read_econtrol(p);
1346 			if ((ecr & ECR_F_EMPTY) && !(ecr & ECR_SERVINTR)
1347 			    && !lost_interrupt) {
1348 				printk(KERN_WARNING PPIP32
1349 				       "%s: lost interrupt in %s\n",
1350 				       p->name, __func__);
1351 				lost_interrupt = 1;
1352 			}
1353 		}
1354 
1355 		/* Disable serviceIntr */
1356 		parport_ip32_frob_econtrol(p, ECR_SERVINTR, ECR_SERVINTR);
1357 
1358 		/* Check FIFO state */
1359 		if (ecr & ECR_F_EMPTY) {
1360 			/* FIFO is empty, fill it up */
1361 			count = priv->fifo_depth;
1362 			break;
1363 		} else if (ecr & ECR_SERVINTR) {
1364 			/* FIFO is not empty, but we know that can safely push
1365 			 * writeIntrThreshold bytes into it */
1366 			count = priv->writeIntrThreshold;
1367 			break;
1368 		}
1369 		/* FIFO is not empty, and we did not get any interrupt.
1370 		 * Either it's time to check for nFault, or a signal is
1371 		 * pending.  This is verified in
1372 		 * parport_ip32_fifo_wait_break(), so we continue the loop. */
1373 	} /* while (1) */
1374 
1375 	return count;
1376 }
1377 
1378 /**
1379  * parport_ip32_fifo_write_block_pio - write a block of data (PIO mode)
1380  * @p:		pointer to &struct parport
1381  * @buf:	buffer of data to write
1382  * @len:	length of buffer @buf
1383  *
1384  * Uses PIO to write the contents of the buffer @buf into the parallel port
1385  * FIFO.  Returns the number of bytes that were actually written.  It can work
1386  * with or without the help of interrupts.  The parallel port must be
1387  * correctly initialized before calling parport_ip32_fifo_write_block_pio().
1388  */
1389 static size_t parport_ip32_fifo_write_block_pio(struct parport *p,
1390 						const void *buf, size_t len)
1391 {
1392 	struct parport_ip32_private * const priv = p->physport->private_data;
1393 	const u8 *bufp = buf;
1394 	size_t left = len;
1395 
1396 	priv->irq_mode = PARPORT_IP32_IRQ_HERE;
1397 
1398 	while (left > 0) {
1399 		unsigned int count;
1400 
1401 		count = (p->irq == PARPORT_IRQ_NONE) ?
1402 			parport_ip32_fwp_wait_polling(p) :
1403 			parport_ip32_fwp_wait_interrupt(p);
1404 		if (count == 0)
1405 			break;	/* Transmission should be stopped */
1406 		if (count > left)
1407 			count = left;
1408 		if (count == 1) {
1409 			writeb(*bufp, priv->regs.fifo);
1410 			bufp++, left--;
1411 		} else {
1412 			writesb(priv->regs.fifo, bufp, count);
1413 			bufp += count, left -= count;
1414 		}
1415 	}
1416 
1417 	priv->irq_mode = PARPORT_IP32_IRQ_FWD;
1418 
1419 	return len - left;
1420 }
1421 
1422 /**
1423  * parport_ip32_fifo_write_block_dma - write a block of data (DMA mode)
1424  * @p:		pointer to &struct parport
1425  * @buf:	buffer of data to write
1426  * @len:	length of buffer @buf
1427  *
1428  * Uses DMA to write the contents of the buffer @buf into the parallel port
1429  * FIFO.  Returns the number of bytes that were actually written.  The
1430  * parallel port must be correctly initialized before calling
1431  * parport_ip32_fifo_write_block_dma().
1432  */
1433 static size_t parport_ip32_fifo_write_block_dma(struct parport *p,
1434 						const void *buf, size_t len)
1435 {
1436 	struct parport_ip32_private * const priv = p->physport->private_data;
1437 	struct parport * const physport = p->physport;
1438 	unsigned long nfault_timeout;
1439 	unsigned long expire;
1440 	size_t written;
1441 	unsigned int ecr;
1442 
1443 	priv->irq_mode = PARPORT_IP32_IRQ_HERE;
1444 
1445 	parport_ip32_dma_start(DMA_TO_DEVICE, (void *)buf, len);
1446 	INIT_COMPLETION(priv->irq_complete);
1447 	parport_ip32_frob_econtrol(p, ECR_DMAEN | ECR_SERVINTR, ECR_DMAEN);
1448 
1449 	nfault_timeout = min((unsigned long)physport->cad->timeout,
1450 			     msecs_to_jiffies(FIFO_NFAULT_TIMEOUT));
1451 	expire = jiffies + physport->cad->timeout;
1452 	while (1) {
1453 		if (parport_ip32_fifo_wait_break(p, expire))
1454 			break;
1455 		wait_for_completion_interruptible_timeout(&priv->irq_complete,
1456 							  nfault_timeout);
1457 		ecr = parport_ip32_read_econtrol(p);
1458 		if (ecr & ECR_SERVINTR)
1459 			break;	/* DMA transfer just finished */
1460 	}
1461 	parport_ip32_dma_stop();
1462 	written = len - parport_ip32_dma_get_residue();
1463 
1464 	priv->irq_mode = PARPORT_IP32_IRQ_FWD;
1465 
1466 	return written;
1467 }
1468 
1469 /**
1470  * parport_ip32_fifo_write_block - write a block of data
1471  * @p:		pointer to &struct parport
1472  * @buf:	buffer of data to write
1473  * @len:	length of buffer @buf
1474  *
1475  * Uses PIO or DMA to write the contents of the buffer @buf into the parallel
1476  * p FIFO.  Returns the number of bytes that were actually written.
1477  */
1478 static size_t parport_ip32_fifo_write_block(struct parport *p,
1479 					    const void *buf, size_t len)
1480 {
1481 	size_t written = 0;
1482 	if (len)
1483 		/* FIXME - Maybe some threshold value should be set for @len
1484 		 * under which we revert to PIO mode? */
1485 		written = (p->modes & PARPORT_MODE_DMA) ?
1486 			parport_ip32_fifo_write_block_dma(p, buf, len) :
1487 			parport_ip32_fifo_write_block_pio(p, buf, len);
1488 	return written;
1489 }
1490 
1491 /**
1492  * parport_ip32_drain_fifo - wait for FIFO to empty
1493  * @p:		pointer to &struct parport
1494  * @timeout:	timeout, in jiffies
1495  *
1496  * This function waits for FIFO to empty.  It returns 1 when FIFO is empty, or
1497  * 0 if the timeout @timeout is reached before, or if a signal is pending.
1498  */
1499 static unsigned int parport_ip32_drain_fifo(struct parport *p,
1500 					    unsigned long timeout)
1501 {
1502 	unsigned long expire = jiffies + timeout;
1503 	unsigned int polling_interval;
1504 	unsigned int counter;
1505 
1506 	/* Busy wait for approx. 200us */
1507 	for (counter = 0; counter < 40; counter++) {
1508 		if (parport_ip32_read_econtrol(p) & ECR_F_EMPTY)
1509 			break;
1510 		if (time_after(jiffies, expire))
1511 			break;
1512 		if (signal_pending(current))
1513 			break;
1514 		udelay(5);
1515 	}
1516 	/* Poll slowly.  Polling interval starts with 1 millisecond, and is
1517 	 * increased exponentially until 128.  */
1518 	polling_interval = 1; /* msecs */
1519 	while (!(parport_ip32_read_econtrol(p) & ECR_F_EMPTY)) {
1520 		if (time_after_eq(jiffies, expire))
1521 			break;
1522 		msleep_interruptible(polling_interval);
1523 		if (signal_pending(current))
1524 			break;
1525 		if (polling_interval < 128)
1526 			polling_interval *= 2;
1527 	}
1528 
1529 	return !!(parport_ip32_read_econtrol(p) & ECR_F_EMPTY);
1530 }
1531 
1532 /**
1533  * parport_ip32_get_fifo_residue - reset FIFO
1534  * @p:		pointer to &struct parport
1535  * @mode:	current operation mode (ECR_MODE_PPF or ECR_MODE_ECP)
1536  *
1537  * This function resets FIFO, and returns the number of bytes remaining in it.
1538  */
1539 static unsigned int parport_ip32_get_fifo_residue(struct parport *p,
1540 						  unsigned int mode)
1541 {
1542 	struct parport_ip32_private * const priv = p->physport->private_data;
1543 	unsigned int residue;
1544 	unsigned int cnfga;
1545 
1546 	/* FIXME - We are missing one byte if the printer is off-line.  I
1547 	 * don't know how to detect this.  It looks that the full bit is not
1548 	 * always reliable.  For the moment, the problem is avoided in most
1549 	 * cases by testing for BUSY in parport_ip32_compat_write_data().
1550 	 */
1551 	if (parport_ip32_read_econtrol(p) & ECR_F_EMPTY)
1552 		residue = 0;
1553 	else {
1554 		pr_debug1(PPIP32 "%s: FIFO is stuck\n", p->name);
1555 
1556 		/* Stop all transfers.
1557 		 *
1558 		 * Microsoft's document instructs to drive DCR_STROBE to 0,
1559 		 * but it doesn't work (at least in Compatibility mode, not
1560 		 * tested in ECP mode).  Switching directly to Test mode (as
1561 		 * in parport_pc) is not an option: it does confuse the port,
1562 		 * ECP service interrupts are no more working after that.  A
1563 		 * hard reset is then needed to revert to a sane state.
1564 		 *
1565 		 * Let's hope that the FIFO is really stuck and that the
1566 		 * peripheral doesn't wake up now.
1567 		 */
1568 		parport_ip32_frob_control(p, DCR_STROBE, 0);
1569 
1570 		/* Fill up FIFO */
1571 		for (residue = priv->fifo_depth; residue > 0; residue--) {
1572 			if (parport_ip32_read_econtrol(p) & ECR_F_FULL)
1573 				break;
1574 			writeb(0x00, priv->regs.fifo);
1575 		}
1576 	}
1577 	if (residue)
1578 		pr_debug1(PPIP32 "%s: %d PWord%s left in FIFO\n",
1579 			  p->name, residue,
1580 			  (residue == 1) ? " was" : "s were");
1581 
1582 	/* Now reset the FIFO */
1583 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1584 
1585 	/* Host recovery for ECP mode */
1586 	if (mode == ECR_MODE_ECP) {
1587 		parport_ip32_data_reverse(p);
1588 		parport_ip32_frob_control(p, DCR_nINIT, 0);
1589 		if (parport_wait_peripheral(p, DSR_PERROR, 0))
1590 			pr_debug1(PPIP32 "%s: PEerror timeout 1 in %s\n",
1591 				  p->name, __func__);
1592 		parport_ip32_frob_control(p, DCR_STROBE, DCR_STROBE);
1593 		parport_ip32_frob_control(p, DCR_nINIT, DCR_nINIT);
1594 		if (parport_wait_peripheral(p, DSR_PERROR, DSR_PERROR))
1595 			pr_debug1(PPIP32 "%s: PEerror timeout 2 in %s\n",
1596 				  p->name, __func__);
1597 	}
1598 
1599 	/* Adjust residue if needed */
1600 	parport_ip32_set_mode(p, ECR_MODE_CFG);
1601 	cnfga = readb(priv->regs.cnfgA);
1602 	if (!(cnfga & CNFGA_nBYTEINTRANS)) {
1603 		pr_debug1(PPIP32 "%s: cnfgA contains 0x%02x\n",
1604 			  p->name, cnfga);
1605 		pr_debug1(PPIP32 "%s: Accounting for extra byte\n",
1606 			  p->name);
1607 		residue++;
1608 	}
1609 
1610 	/* Don't care about partial PWords since we do not support
1611 	 * PWord != 1 byte. */
1612 
1613 	/* Back to forward PS2 mode. */
1614 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1615 	parport_ip32_data_forward(p);
1616 
1617 	return residue;
1618 }
1619 
1620 /**
1621  * parport_ip32_compat_write_data - write a block of data in SPP mode
1622  * @p:		pointer to &struct parport
1623  * @buf:	buffer of data to write
1624  * @len:	length of buffer @buf
1625  * @flags:	ignored
1626  */
1627 static size_t parport_ip32_compat_write_data(struct parport *p,
1628 					     const void *buf, size_t len,
1629 					     int flags)
1630 {
1631 	static unsigned int ready_before = 1;
1632 	struct parport_ip32_private * const priv = p->physport->private_data;
1633 	struct parport * const physport = p->physport;
1634 	size_t written = 0;
1635 
1636 	/* Special case: a timeout of zero means we cannot call schedule().
1637 	 * Also if O_NONBLOCK is set then use the default implementation. */
1638 	if (physport->cad->timeout <= PARPORT_INACTIVITY_O_NONBLOCK)
1639 		return parport_ieee1284_write_compat(p, buf, len, flags);
1640 
1641 	/* Reset FIFO, go in forward mode, and disable ackIntEn */
1642 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1643 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
1644 	parport_ip32_data_forward(p);
1645 	parport_ip32_disable_irq(p);
1646 	parport_ip32_set_mode(p, ECR_MODE_PPF);
1647 	physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;
1648 
1649 	/* Wait for peripheral to become ready */
1650 	if (parport_wait_peripheral(p, DSR_nBUSY | DSR_nFAULT,
1651 				       DSR_nBUSY | DSR_nFAULT)) {
1652 		/* Avoid to flood the logs */
1653 		if (ready_before)
1654 			printk(KERN_INFO PPIP32 "%s: not ready in %s\n",
1655 			       p->name, __func__);
1656 		ready_before = 0;
1657 		goto stop;
1658 	}
1659 	ready_before = 1;
1660 
1661 	written = parport_ip32_fifo_write_block(p, buf, len);
1662 
1663 	/* Wait FIFO to empty.  Timeout is proportional to FIFO_depth.  */
1664 	parport_ip32_drain_fifo(p, physport->cad->timeout * priv->fifo_depth);
1665 
1666 	/* Check for a potential residue */
1667 	written -= parport_ip32_get_fifo_residue(p, ECR_MODE_PPF);
1668 
1669 	/* Then, wait for BUSY to get low. */
1670 	if (parport_wait_peripheral(p, DSR_nBUSY, DSR_nBUSY))
1671 		printk(KERN_DEBUG PPIP32 "%s: BUSY timeout in %s\n",
1672 		       p->name, __func__);
1673 
1674 stop:
1675 	/* Reset FIFO */
1676 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1677 	physport->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
1678 
1679 	return written;
1680 }
1681 
1682 /*
1683  * FIXME - Insert here parport_ip32_ecp_read_data().
1684  */
1685 
1686 /**
1687  * parport_ip32_ecp_write_data - write a block of data in ECP mode
1688  * @p:		pointer to &struct parport
1689  * @buf:	buffer of data to write
1690  * @len:	length of buffer @buf
1691  * @flags:	ignored
1692  */
1693 static size_t parport_ip32_ecp_write_data(struct parport *p,
1694 					  const void *buf, size_t len,
1695 					  int flags)
1696 {
1697 	static unsigned int ready_before = 1;
1698 	struct parport_ip32_private * const priv = p->physport->private_data;
1699 	struct parport * const physport = p->physport;
1700 	size_t written = 0;
1701 
1702 	/* Special case: a timeout of zero means we cannot call schedule().
1703 	 * Also if O_NONBLOCK is set then use the default implementation. */
1704 	if (physport->cad->timeout <= PARPORT_INACTIVITY_O_NONBLOCK)
1705 		return parport_ieee1284_ecp_write_data(p, buf, len, flags);
1706 
1707 	/* Negotiate to forward mode if necessary. */
1708 	if (physport->ieee1284.phase != IEEE1284_PH_FWD_IDLE) {
1709 		/* Event 47: Set nInit high. */
1710 		parport_ip32_frob_control(p, DCR_nINIT | DCR_AUTOFD,
1711 					     DCR_nINIT | DCR_AUTOFD);
1712 
1713 		/* Event 49: PError goes high. */
1714 		if (parport_wait_peripheral(p, DSR_PERROR, DSR_PERROR)) {
1715 			printk(KERN_DEBUG PPIP32 "%s: PError timeout in %s",
1716 			       p->name, __func__);
1717 			physport->ieee1284.phase = IEEE1284_PH_ECP_DIR_UNKNOWN;
1718 			return 0;
1719 		}
1720 	}
1721 
1722 	/* Reset FIFO, go in forward mode, and disable ackIntEn */
1723 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1724 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
1725 	parport_ip32_data_forward(p);
1726 	parport_ip32_disable_irq(p);
1727 	parport_ip32_set_mode(p, ECR_MODE_ECP);
1728 	physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;
1729 
1730 	/* Wait for peripheral to become ready */
1731 	if (parport_wait_peripheral(p, DSR_nBUSY | DSR_nFAULT,
1732 				       DSR_nBUSY | DSR_nFAULT)) {
1733 		/* Avoid to flood the logs */
1734 		if (ready_before)
1735 			printk(KERN_INFO PPIP32 "%s: not ready in %s\n",
1736 			       p->name, __func__);
1737 		ready_before = 0;
1738 		goto stop;
1739 	}
1740 	ready_before = 1;
1741 
1742 	written = parport_ip32_fifo_write_block(p, buf, len);
1743 
1744 	/* Wait FIFO to empty.  Timeout is proportional to FIFO_depth.  */
1745 	parport_ip32_drain_fifo(p, physport->cad->timeout * priv->fifo_depth);
1746 
1747 	/* Check for a potential residue */
1748 	written -= parport_ip32_get_fifo_residue(p, ECR_MODE_ECP);
1749 
1750 	/* Then, wait for BUSY to get low. */
1751 	if (parport_wait_peripheral(p, DSR_nBUSY, DSR_nBUSY))
1752 		printk(KERN_DEBUG PPIP32 "%s: BUSY timeout in %s\n",
1753 		       p->name, __func__);
1754 
1755 stop:
1756 	/* Reset FIFO */
1757 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1758 	physport->ieee1284.phase = IEEE1284_PH_FWD_IDLE;
1759 
1760 	return written;
1761 }
1762 
1763 /*
1764  * FIXME - Insert here parport_ip32_ecp_write_addr().
1765  */
1766 
1767 /*--- Default parport operations ---------------------------------------*/
1768 
1769 static __initdata struct parport_operations parport_ip32_ops = {
1770 	.write_data		= parport_ip32_write_data,
1771 	.read_data		= parport_ip32_read_data,
1772 
1773 	.write_control		= parport_ip32_write_control,
1774 	.read_control		= parport_ip32_read_control,
1775 	.frob_control		= parport_ip32_frob_control,
1776 
1777 	.read_status		= parport_ip32_read_status,
1778 
1779 	.enable_irq		= parport_ip32_enable_irq,
1780 	.disable_irq		= parport_ip32_disable_irq,
1781 
1782 	.data_forward		= parport_ip32_data_forward,
1783 	.data_reverse		= parport_ip32_data_reverse,
1784 
1785 	.init_state		= parport_ip32_init_state,
1786 	.save_state		= parport_ip32_save_state,
1787 	.restore_state		= parport_ip32_restore_state,
1788 
1789 	.epp_write_data		= parport_ieee1284_epp_write_data,
1790 	.epp_read_data		= parport_ieee1284_epp_read_data,
1791 	.epp_write_addr		= parport_ieee1284_epp_write_addr,
1792 	.epp_read_addr		= parport_ieee1284_epp_read_addr,
1793 
1794 	.ecp_write_data		= parport_ieee1284_ecp_write_data,
1795 	.ecp_read_data		= parport_ieee1284_ecp_read_data,
1796 	.ecp_write_addr		= parport_ieee1284_ecp_write_addr,
1797 
1798 	.compat_write_data	= parport_ieee1284_write_compat,
1799 	.nibble_read_data	= parport_ieee1284_read_nibble,
1800 	.byte_read_data		= parport_ieee1284_read_byte,
1801 
1802 	.owner			= THIS_MODULE,
1803 };
1804 
1805 /*--- Device detection -------------------------------------------------*/
1806 
1807 /**
1808  * parport_ip32_ecp_supported - check for an ECP port
1809  * @p:		pointer to the &parport structure
1810  *
1811  * Returns 1 if an ECP port is found, and 0 otherwise.  This function actually
1812  * checks if an Extended Control Register seems to be present.  On successful
1813  * return, the port is placed in SPP mode.
1814  */
1815 static __init unsigned int parport_ip32_ecp_supported(struct parport *p)
1816 {
1817 	struct parport_ip32_private * const priv = p->physport->private_data;
1818 	unsigned int ecr;
1819 
1820 	ecr = ECR_MODE_PS2 | ECR_nERRINTR | ECR_SERVINTR;
1821 	writeb(ecr, priv->regs.ecr);
1822 	if (readb(priv->regs.ecr) != (ecr | ECR_F_EMPTY))
1823 		goto fail;
1824 
1825 	pr_probe(p, "Found working ECR register\n");
1826 	parport_ip32_set_mode(p, ECR_MODE_SPP);
1827 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
1828 	return 1;
1829 
1830 fail:
1831 	pr_probe(p, "ECR register not found\n");
1832 	return 0;
1833 }
1834 
1835 /**
1836  * parport_ip32_fifo_supported - check for FIFO parameters
1837  * @p:		pointer to the &parport structure
1838  *
1839  * Check for FIFO parameters of an Extended Capabilities Port.  Returns 1 on
1840  * success, and 0 otherwise.  Adjust FIFO parameters in the parport structure.
1841  * On return, the port is placed in SPP mode.
1842  */
1843 static __init unsigned int parport_ip32_fifo_supported(struct parport *p)
1844 {
1845 	struct parport_ip32_private * const priv = p->physport->private_data;
1846 	unsigned int configa, configb;
1847 	unsigned int pword;
1848 	unsigned int i;
1849 
1850 	/* Configuration mode */
1851 	parport_ip32_set_mode(p, ECR_MODE_CFG);
1852 	configa = readb(priv->regs.cnfgA);
1853 	configb = readb(priv->regs.cnfgB);
1854 
1855 	/* Find out PWord size */
1856 	switch (configa & CNFGA_ID_MASK) {
1857 	case CNFGA_ID_8:
1858 		pword = 1;
1859 		break;
1860 	case CNFGA_ID_16:
1861 		pword = 2;
1862 		break;
1863 	case CNFGA_ID_32:
1864 		pword = 4;
1865 		break;
1866 	default:
1867 		pr_probe(p, "Unknown implementation ID: 0x%0x\n",
1868 			 (configa & CNFGA_ID_MASK) >> CNFGA_ID_SHIFT);
1869 		goto fail;
1870 		break;
1871 	}
1872 	if (pword != 1) {
1873 		pr_probe(p, "Unsupported PWord size: %u\n", pword);
1874 		goto fail;
1875 	}
1876 	priv->pword = pword;
1877 	pr_probe(p, "PWord is %u bits\n", 8 * priv->pword);
1878 
1879 	/* Check for compression support */
1880 	writeb(configb | CNFGB_COMPRESS, priv->regs.cnfgB);
1881 	if (readb(priv->regs.cnfgB) & CNFGB_COMPRESS)
1882 		pr_probe(p, "Hardware compression detected (unsupported)\n");
1883 	writeb(configb & ~CNFGB_COMPRESS, priv->regs.cnfgB);
1884 
1885 	/* Reset FIFO and go in test mode (no interrupt, no DMA) */
1886 	parport_ip32_set_mode(p, ECR_MODE_TST);
1887 
1888 	/* FIFO must be empty now */
1889 	if (!(readb(priv->regs.ecr) & ECR_F_EMPTY)) {
1890 		pr_probe(p, "FIFO not reset\n");
1891 		goto fail;
1892 	}
1893 
1894 	/* Find out FIFO depth. */
1895 	priv->fifo_depth = 0;
1896 	for (i = 0; i < 1024; i++) {
1897 		if (readb(priv->regs.ecr) & ECR_F_FULL) {
1898 			/* FIFO full */
1899 			priv->fifo_depth = i;
1900 			break;
1901 		}
1902 		writeb((u8)i, priv->regs.fifo);
1903 	}
1904 	if (i >= 1024) {
1905 		pr_probe(p, "Can't fill FIFO\n");
1906 		goto fail;
1907 	}
1908 	if (!priv->fifo_depth) {
1909 		pr_probe(p, "Can't get FIFO depth\n");
1910 		goto fail;
1911 	}
1912 	pr_probe(p, "FIFO is %u PWords deep\n", priv->fifo_depth);
1913 
1914 	/* Enable interrupts */
1915 	parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
1916 
1917 	/* Find out writeIntrThreshold: number of PWords we know we can write
1918 	 * if we get an interrupt. */
1919 	priv->writeIntrThreshold = 0;
1920 	for (i = 0; i < priv->fifo_depth; i++) {
1921 		if (readb(priv->regs.fifo) != (u8)i) {
1922 			pr_probe(p, "Invalid data in FIFO\n");
1923 			goto fail;
1924 		}
1925 		if (!priv->writeIntrThreshold
1926 		    && readb(priv->regs.ecr) & ECR_SERVINTR)
1927 			/* writeIntrThreshold reached */
1928 			priv->writeIntrThreshold = i + 1;
1929 		if (i + 1 < priv->fifo_depth
1930 		    && readb(priv->regs.ecr) & ECR_F_EMPTY) {
1931 			/* FIFO empty before the last byte? */
1932 			pr_probe(p, "Data lost in FIFO\n");
1933 			goto fail;
1934 		}
1935 	}
1936 	if (!priv->writeIntrThreshold) {
1937 		pr_probe(p, "Can't get writeIntrThreshold\n");
1938 		goto fail;
1939 	}
1940 	pr_probe(p, "writeIntrThreshold is %u\n", priv->writeIntrThreshold);
1941 
1942 	/* FIFO must be empty now */
1943 	if (!(readb(priv->regs.ecr) & ECR_F_EMPTY)) {
1944 		pr_probe(p, "Can't empty FIFO\n");
1945 		goto fail;
1946 	}
1947 
1948 	/* Reset FIFO */
1949 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1950 	/* Set reverse direction (must be in PS2 mode) */
1951 	parport_ip32_data_reverse(p);
1952 	/* Test FIFO, no interrupt, no DMA */
1953 	parport_ip32_set_mode(p, ECR_MODE_TST);
1954 	/* Enable interrupts */
1955 	parport_ip32_frob_econtrol(p, ECR_SERVINTR, 0);
1956 
1957 	/* Find out readIntrThreshold: number of PWords we can read if we get
1958 	 * an interrupt. */
1959 	priv->readIntrThreshold = 0;
1960 	for (i = 0; i < priv->fifo_depth; i++) {
1961 		writeb(0xaa, priv->regs.fifo);
1962 		if (readb(priv->regs.ecr) & ECR_SERVINTR) {
1963 			/* readIntrThreshold reached */
1964 			priv->readIntrThreshold = i + 1;
1965 			break;
1966 		}
1967 	}
1968 	if (!priv->readIntrThreshold) {
1969 		pr_probe(p, "Can't get readIntrThreshold\n");
1970 		goto fail;
1971 	}
1972 	pr_probe(p, "readIntrThreshold is %u\n", priv->readIntrThreshold);
1973 
1974 	/* Reset ECR */
1975 	parport_ip32_set_mode(p, ECR_MODE_PS2);
1976 	parport_ip32_data_forward(p);
1977 	parport_ip32_set_mode(p, ECR_MODE_SPP);
1978 	return 1;
1979 
1980 fail:
1981 	priv->fifo_depth = 0;
1982 	parport_ip32_set_mode(p, ECR_MODE_SPP);
1983 	return 0;
1984 }
1985 
1986 /*--- Initialization code ----------------------------------------------*/
1987 
1988 /**
1989  * parport_ip32_make_isa_registers - compute (ISA) register addresses
1990  * @regs:	pointer to &struct parport_ip32_regs to fill
1991  * @base:	base address of standard and EPP registers
1992  * @base_hi:	base address of ECP registers
1993  * @regshift:	how much to shift register offset by
1994  *
1995  * Compute register addresses, according to the ISA standard.  The addresses
1996  * of the standard and EPP registers are computed from address @base.  The
1997  * addresses of the ECP registers are computed from address @base_hi.
1998  */
1999 static void __init
2000 parport_ip32_make_isa_registers(struct parport_ip32_regs *regs,
2001 				void __iomem *base, void __iomem *base_hi,
2002 				unsigned int regshift)
2003 {
2004 #define r_base(offset)    ((u8 __iomem *)base    + ((offset) << regshift))
2005 #define r_base_hi(offset) ((u8 __iomem *)base_hi + ((offset) << regshift))
2006 	*regs = (struct parport_ip32_regs){
2007 		.data		= r_base(0),
2008 		.dsr		= r_base(1),
2009 		.dcr		= r_base(2),
2010 		.eppAddr	= r_base(3),
2011 		.eppData0	= r_base(4),
2012 		.eppData1	= r_base(5),
2013 		.eppData2	= r_base(6),
2014 		.eppData3	= r_base(7),
2015 		.ecpAFifo	= r_base(0),
2016 		.fifo		= r_base_hi(0),
2017 		.cnfgA		= r_base_hi(0),
2018 		.cnfgB		= r_base_hi(1),
2019 		.ecr		= r_base_hi(2)
2020 	};
2021 #undef r_base_hi
2022 #undef r_base
2023 }
2024 
2025 /**
2026  * parport_ip32_probe_port - probe and register IP32 built-in parallel port
2027  *
2028  * Returns the new allocated &parport structure.  On error, an error code is
2029  * encoded in return value with the ERR_PTR function.
2030  */
2031 static __init struct parport *parport_ip32_probe_port(void)
2032 {
2033 	struct parport_ip32_regs regs;
2034 	struct parport_ip32_private *priv = NULL;
2035 	struct parport_operations *ops = NULL;
2036 	struct parport *p = NULL;
2037 	int err;
2038 
2039 	parport_ip32_make_isa_registers(&regs, &mace->isa.parallel,
2040 					&mace->isa.ecp1284, 8 /* regshift */);
2041 
2042 	ops = kmalloc(sizeof(struct parport_operations), GFP_KERNEL);
2043 	priv = kmalloc(sizeof(struct parport_ip32_private), GFP_KERNEL);
2044 	p = parport_register_port(0, PARPORT_IRQ_NONE, PARPORT_DMA_NONE, ops);
2045 	if (ops == NULL || priv == NULL || p == NULL) {
2046 		err = -ENOMEM;
2047 		goto fail;
2048 	}
2049 	p->base = MACE_BASE + offsetof(struct sgi_mace, isa.parallel);
2050 	p->base_hi = MACE_BASE + offsetof(struct sgi_mace, isa.ecp1284);
2051 	p->private_data = priv;
2052 
2053 	*ops = parport_ip32_ops;
2054 	*priv = (struct parport_ip32_private){
2055 		.regs			= regs,
2056 		.dcr_writable		= DCR_DIR | DCR_SELECT | DCR_nINIT |
2057 					  DCR_AUTOFD | DCR_STROBE,
2058 		.irq_mode		= PARPORT_IP32_IRQ_FWD,
2059 	};
2060 	init_completion(&priv->irq_complete);
2061 
2062 	/* Probe port. */
2063 	if (!parport_ip32_ecp_supported(p)) {
2064 		err = -ENODEV;
2065 		goto fail;
2066 	}
2067 	parport_ip32_dump_state(p, "begin init", 0);
2068 
2069 	/* We found what looks like a working ECR register.  Simply assume
2070 	 * that all modes are correctly supported.  Enable basic modes. */
2071 	p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
2072 	p->modes |= PARPORT_MODE_TRISTATE;
2073 
2074 	if (!parport_ip32_fifo_supported(p)) {
2075 		printk(KERN_WARNING PPIP32
2076 		       "%s: error: FIFO disabled\n", p->name);
2077 		/* Disable hardware modes depending on a working FIFO. */
2078 		features &= ~PARPORT_IP32_ENABLE_SPP;
2079 		features &= ~PARPORT_IP32_ENABLE_ECP;
2080 		/* DMA is not needed if FIFO is not supported.  */
2081 		features &= ~PARPORT_IP32_ENABLE_DMA;
2082 	}
2083 
2084 	/* Request IRQ */
2085 	if (features & PARPORT_IP32_ENABLE_IRQ) {
2086 		int irq = MACEISA_PARALLEL_IRQ;
2087 		if (request_irq(irq, parport_ip32_interrupt, 0, p->name, p)) {
2088 			printk(KERN_WARNING PPIP32
2089 			       "%s: error: IRQ disabled\n", p->name);
2090 			/* DMA cannot work without interrupts. */
2091 			features &= ~PARPORT_IP32_ENABLE_DMA;
2092 		} else {
2093 			pr_probe(p, "Interrupt support enabled\n");
2094 			p->irq = irq;
2095 			priv->dcr_writable |= DCR_IRQ;
2096 		}
2097 	}
2098 
2099 	/* Allocate DMA resources */
2100 	if (features & PARPORT_IP32_ENABLE_DMA) {
2101 		if (parport_ip32_dma_register())
2102 			printk(KERN_WARNING PPIP32
2103 			       "%s: error: DMA disabled\n", p->name);
2104 		else {
2105 			pr_probe(p, "DMA support enabled\n");
2106 			p->dma = 0; /* arbitrary value != PARPORT_DMA_NONE */
2107 			p->modes |= PARPORT_MODE_DMA;
2108 		}
2109 	}
2110 
2111 	if (features & PARPORT_IP32_ENABLE_SPP) {
2112 		/* Enable compatibility FIFO mode */
2113 		p->ops->compat_write_data = parport_ip32_compat_write_data;
2114 		p->modes |= PARPORT_MODE_COMPAT;
2115 		pr_probe(p, "Hardware support for SPP mode enabled\n");
2116 	}
2117 	if (features & PARPORT_IP32_ENABLE_EPP) {
2118 		/* Set up access functions to use EPP hardware. */
2119 		p->ops->epp_read_data = parport_ip32_epp_read_data;
2120 		p->ops->epp_write_data = parport_ip32_epp_write_data;
2121 		p->ops->epp_read_addr = parport_ip32_epp_read_addr;
2122 		p->ops->epp_write_addr = parport_ip32_epp_write_addr;
2123 		p->modes |= PARPORT_MODE_EPP;
2124 		pr_probe(p, "Hardware support for EPP mode enabled\n");
2125 	}
2126 	if (features & PARPORT_IP32_ENABLE_ECP) {
2127 		/* Enable ECP FIFO mode */
2128 		p->ops->ecp_write_data = parport_ip32_ecp_write_data;
2129 		/* FIXME - not implemented */
2130 /*		p->ops->ecp_read_data  = parport_ip32_ecp_read_data; */
2131 /*		p->ops->ecp_write_addr = parport_ip32_ecp_write_addr; */
2132 		p->modes |= PARPORT_MODE_ECP;
2133 		pr_probe(p, "Hardware support for ECP mode enabled\n");
2134 	}
2135 
2136 	/* Initialize the port with sensible values */
2137 	parport_ip32_set_mode(p, ECR_MODE_PS2);
2138 	parport_ip32_write_control(p, DCR_SELECT | DCR_nINIT);
2139 	parport_ip32_data_forward(p);
2140 	parport_ip32_disable_irq(p);
2141 	parport_ip32_write_data(p, 0x00);
2142 	parport_ip32_dump_state(p, "end init", 0);
2143 
2144 	/* Print out what we found */
2145 	printk(KERN_INFO "%s: SGI IP32 at 0x%lx (0x%lx)",
2146 	       p->name, p->base, p->base_hi);
2147 	if (p->irq != PARPORT_IRQ_NONE)
2148 		printk(", irq %d", p->irq);
2149 	printk(" [");
2150 #define printmode(x)	if (p->modes & PARPORT_MODE_##x)		\
2151 				printk("%s%s", f++ ? "," : "", #x)
2152 	{
2153 		unsigned int f = 0;
2154 		printmode(PCSPP);
2155 		printmode(TRISTATE);
2156 		printmode(COMPAT);
2157 		printmode(EPP);
2158 		printmode(ECP);
2159 		printmode(DMA);
2160 	}
2161 #undef printmode
2162 	printk("]\n");
2163 
2164 	parport_announce_port(p);
2165 	return p;
2166 
2167 fail:
2168 	if (p)
2169 		parport_put_port(p);
2170 	kfree(priv);
2171 	kfree(ops);
2172 	return ERR_PTR(err);
2173 }
2174 
2175 /**
2176  * parport_ip32_unregister_port - unregister a parallel port
2177  * @p:		pointer to the &struct parport
2178  *
2179  * Unregisters a parallel port and free previously allocated resources
2180  * (memory, IRQ, ...).
2181  */
2182 static __exit void parport_ip32_unregister_port(struct parport *p)
2183 {
2184 	struct parport_ip32_private * const priv = p->physport->private_data;
2185 	struct parport_operations *ops = p->ops;
2186 
2187 	parport_remove_port(p);
2188 	if (p->modes & PARPORT_MODE_DMA)
2189 		parport_ip32_dma_unregister();
2190 	if (p->irq != PARPORT_IRQ_NONE)
2191 		free_irq(p->irq, p);
2192 	parport_put_port(p);
2193 	kfree(priv);
2194 	kfree(ops);
2195 }
2196 
2197 /**
2198  * parport_ip32_init - module initialization function
2199  */
2200 static int __init parport_ip32_init(void)
2201 {
2202 	pr_info(PPIP32 "SGI IP32 built-in parallel port driver v0.6\n");
2203 	pr_debug1(PPIP32 "Compiled on %s, %s\n", __DATE__, __TIME__);
2204 	this_port = parport_ip32_probe_port();
2205 	return IS_ERR(this_port) ? PTR_ERR(this_port) : 0;
2206 }
2207 
2208 /**
2209  * parport_ip32_exit - module termination function
2210  */
2211 static void __exit parport_ip32_exit(void)
2212 {
2213 	parport_ip32_unregister_port(this_port);
2214 }
2215 
2216 /*--- Module stuff -----------------------------------------------------*/
2217 
2218 MODULE_AUTHOR("Arnaud Giersch <arnaud.giersch@free.fr>");
2219 MODULE_DESCRIPTION("SGI IP32 built-in parallel port driver");
2220 MODULE_LICENSE("GPL");
2221 MODULE_VERSION("0.6");		/* update in parport_ip32_init() too */
2222 
2223 module_init(parport_ip32_init);
2224 module_exit(parport_ip32_exit);
2225 
2226 module_param(verbose_probing, bool, S_IRUGO);
2227 MODULE_PARM_DESC(verbose_probing, "Log chit-chat during initialization");
2228 
2229 module_param(features, uint, S_IRUGO);
2230 MODULE_PARM_DESC(features,
2231 		 "Bit mask of features to enable"
2232 		 ", bit 0: IRQ support"
2233 		 ", bit 1: DMA support"
2234 		 ", bit 2: hardware SPP mode"
2235 		 ", bit 3: hardware EPP mode"
2236 		 ", bit 4: hardware ECP mode");
2237 
2238 /*--- Inform (X)Emacs about preferred coding style ---------------------*/
2239 /*
2240  * Local Variables:
2241  * mode: c
2242  * c-file-style: "linux"
2243  * indent-tabs-mode: t
2244  * tab-width: 8
2245  * fill-column: 78
2246  * ispell-local-dictionary: "american"
2247  * End:
2248  */
2249