1 
2 /*********************************************************************
3  *
4  *	vlsi_ir.h:	VLSI82C147 PCI IrDA controller driver for Linux
5  *
6  *	Version:	0.5
7  *
8  *	Copyright (c) 2001-2003 Martin Diehl
9  *
10  *	This program is free software; you can redistribute it and/or
11  *	modify it under the terms of the GNU General Public License as
12  *	published by the Free Software Foundation; either version 2 of
13  *	the License, or (at your option) any later version.
14  *
15  *	This program is distributed in the hope that it will be useful,
16  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18  *	GNU General Public License for more details.
19  *
20  *	You should have received a copy of the GNU General Public License
21  *	along with this program; if not, write to the Free Software
22  *	Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23  *	MA 02111-1307 USA
24  *
25  ********************************************************************/
26 
27 #ifndef IRDA_VLSI_FIR_H
28 #define IRDA_VLSI_FIR_H
29 
30 /* ================================================================
31  * compatibility stuff
32  */
33 
34 /* definitions not present in pci_ids.h */
35 
36 #ifndef PCI_CLASS_WIRELESS_IRDA
37 #define PCI_CLASS_WIRELESS_IRDA		0x0d00
38 #endif
39 
40 #ifndef PCI_CLASS_SUBCLASS_MASK
41 #define PCI_CLASS_SUBCLASS_MASK		0xffff
42 #endif
43 
44 /* ================================================================ */
45 
46 /* non-standard PCI registers */
47 
48 enum vlsi_pci_regs {
49 	VLSI_PCI_CLKCTL		= 0x40,		/* chip clock input control */
50 	VLSI_PCI_MSTRPAGE	= 0x41,		/* addr [31:24] for all busmaster cycles */
51 	VLSI_PCI_IRMISC		= 0x42		/* mainly legacy UART related */
52 };
53 
54 /* ------------------------------------------ */
55 
56 /* VLSI_PCI_CLKCTL: Clock Control Register (u8, rw) */
57 
58 /* Three possible clock sources: either on-chip 48MHz PLL or
59  * external clock applied to EXTCLK pin. External clock may
60  * be either 48MHz or 40MHz, which is indicated by XCKSEL.
61  * CLKSTP controls whether the selected clock source gets
62  * connected to the IrDA block.
63  *
64  * On my HP OB-800 the BIOS sets external 40MHz clock as source
65  * when IrDA enabled and I've never detected any PLL lock success.
66  * Apparently the 14.3...MHz OSC input required for the PLL to work
67  * is not connected and the 40MHz EXTCLK is provided externally.
68  * At least this is what makes the driver working for me.
69  */
70 
71 enum vlsi_pci_clkctl {
72 
73 	/* PLL control */
74 
75 	CLKCTL_PD_INV		= 0x04,		/* PD#: inverted power down signal,
76 						 * i.e. PLL is powered, if PD_INV set */
77 	CLKCTL_LOCK		= 0x40,		/* (ro) set, if PLL is locked */
78 
79 	/* clock source selection */
80 
81 	CLKCTL_EXTCLK		= 0x20,		/* set to select external clock input, not PLL */
82 	CLKCTL_XCKSEL		= 0x10,		/* set to indicate EXTCLK is 40MHz, not 48MHz */
83 
84 	/* IrDA block control */
85 
86 	CLKCTL_CLKSTP		= 0x80,		/* set to disconnect from selected clock source */
87 	CLKCTL_WAKE		= 0x08		/* set to enable wakeup feature: whenever IR activity
88 						 * is detected, PD_INV gets set(?) and CLKSTP cleared */
89 };
90 
91 /* ------------------------------------------ */
92 
93 /* VLSI_PCI_MSTRPAGE: Master Page Register (u8, rw) and busmastering stuff */
94 
95 #define DMA_MASK_USED_BY_HW	0xffffffff
96 #define DMA_MASK_MSTRPAGE	0x00ffffff
97 #define MSTRPAGE_VALUE		(DMA_MASK_MSTRPAGE >> 24)
98 
99 	/* PCI busmastering is somewhat special for this guy - in short:
100 	 *
101 	 * We select to operate using fixed MSTRPAGE=0, use ISA DMA
102 	 * address restrictions to make the PCI BM api aware of this,
103 	 * but ensure the hardware is dealing with real 32bit access.
104 	 *
105 	 * In detail:
106 	 * The chip executes normal 32bit busmaster cycles, i.e.
107 	 * drives all 32 address lines. These addresses however are
108 	 * composed of [0:23] taken from various busaddr-pointers
109 	 * and [24:31] taken from the MSTRPAGE register in the VLSI82C147
110 	 * config space. Therefore _all_ busmastering must be
111 	 * targeted to/from one single 16MB (busaddr-) superpage!
112 	 * The point is to make sure all the allocations for memory
113 	 * locations with busmaster access (ring descriptors, buffers)
114 	 * are indeed bus-mappable to the same 16MB range (for x86 this
115 	 * means they must reside in the same 16MB physical memory address
116 	 * range). The only constraint we have which supports "several objects
117 	 * mappable to common 16MB range" paradigma, is the old ISA DMA
118 	 * restriction to the first 16MB of physical address range.
119 	 * Hence the approach here is to enable PCI busmaster support using
120 	 * the correct 32bit dma-mask used by the chip. Afterwards the device's
121 	 * dma-mask gets restricted to 24bit, which must be honoured somehow by
122 	 * all allocations for memory areas to be exposed to the chip ...
123 	 *
124 	 * Note:
125 	 * Don't be surprised to get "Setting latency timer..." messages every
126 	 * time when PCI busmastering is enabled for the chip.
127 	 * The chip has its PCI latency timer RO fixed at 0 - which is not a
128 	 * problem here, because it is never requesting _burst_ transactions.
129 	 */
130 
131 /* ------------------------------------------ */
132 
133 /* VLSI_PCIIRMISC: IR Miscellaneous Register (u8, rw) */
134 
135 /* legacy UART emulation - not used by this driver - would require:
136  * (see below for some register-value definitions)
137  *
138  *	- IRMISC_UARTEN must be set to enable UART address decoding
139  *	- IRMISC_UARTSEL configured
140  *	- IRCFG_MASTER must be cleared
141  *	- IRCFG_SIR must be set
142  *	- IRENABLE_PHYANDCLOCK must be asserted 0->1 (and hence IRENABLE_SIR_ON)
143  */
144 
145 enum vlsi_pci_irmisc {
146 
147 	/* IR transceiver control */
148 
149 	IRMISC_IRRAIL		= 0x40,		/* (ro?) IR rail power indication (and control?)
150 						 * 0=3.3V / 1=5V. Probably set during power-on?
151 						 * unclear - not touched by driver */
152 	IRMISC_IRPD		= 0x08,		/* transceiver power down, if set */
153 
154 	/* legacy UART control */
155 
156 	IRMISC_UARTTST		= 0x80,		/* UART test mode - "always write 0" */
157 	IRMISC_UARTEN		= 0x04,		/* enable UART address decoding */
158 
159 	/* bits [1:0] IRMISC_UARTSEL to select legacy UART address */
160 
161 	IRMISC_UARTSEL_3f8	= 0x00,
162 	IRMISC_UARTSEL_2f8	= 0x01,
163 	IRMISC_UARTSEL_3e8	= 0x02,
164 	IRMISC_UARTSEL_2e8	= 0x03
165 };
166 
167 /* ================================================================ */
168 
169 /* registers mapped to 32 byte PCI IO space */
170 
171 /* note: better access all registers at the indicated u8/u16 size
172  *	 although some of them contain only 1 byte of information.
173  *	 some of them (particaluarly PROMPT and IRCFG) ignore
174  *	 access when using the wrong addressing mode!
175  */
176 
177 enum vlsi_pio_regs {
178 	VLSI_PIO_IRINTR		= 0x00,		/* interrupt enable/request (u8, rw) */
179 	VLSI_PIO_RINGPTR	= 0x02,		/* rx/tx ring pointer (u16, ro) */
180 	VLSI_PIO_RINGBASE	= 0x04,		/* [23:10] of ring address (u16, rw) */
181 	VLSI_PIO_RINGSIZE	= 0x06,		/* rx/tx ring size (u16, rw) */
182 	VLSI_PIO_PROMPT		= 0x08, 	/* triggers ring processing (u16, wo) */
183 	/* 0x0a-0x0f: reserved / duplicated UART regs */
184 	VLSI_PIO_IRCFG		= 0x10,		/* configuration select (u16, rw) */
185 	VLSI_PIO_SIRFLAG	= 0x12,		/* BOF/EOF for filtered SIR (u16, ro) */
186 	VLSI_PIO_IRENABLE	= 0x14,		/* enable and status register (u16, rw/ro) */
187 	VLSI_PIO_PHYCTL		= 0x16,		/* physical layer current status (u16, ro) */
188 	VLSI_PIO_NPHYCTL	= 0x18,		/* next physical layer select (u16, rw) */
189 	VLSI_PIO_MAXPKT		= 0x1a,		/* [11:0] max len for packet receive (u16, rw) */
190 	VLSI_PIO_RCVBCNT	= 0x1c		/* current receive-FIFO byte count (u16, ro) */
191 	/* 0x1e-0x1f: reserved / duplicated UART regs */
192 };
193 
194 /* ------------------------------------------ */
195 
196 /* VLSI_PIO_IRINTR: Interrupt Register (u8, rw) */
197 
198 /* enable-bits:
199  *		1 = enable / 0 = disable
200  * interrupt condition bits:
201  * 		set according to corresponding interrupt source
202  *		(regardless of the state of the enable bits)
203  *		enable bit status indicates whether interrupt gets raised
204  *		write-to-clear
205  * note: RPKTINT and TPKTINT behave different in legacy UART mode (which we don't use :-)
206  */
207 
208 enum vlsi_pio_irintr {
209 	IRINTR_ACTEN	= 0x80,	/* activity interrupt enable */
210 	IRINTR_ACTIVITY	= 0x40,	/* activity monitor (traffic detected) */
211 	IRINTR_RPKTEN	= 0x20,	/* receive packet interrupt enable*/
212 	IRINTR_RPKTINT	= 0x10,	/* rx-packet transferred from fifo to memory finished */
213 	IRINTR_TPKTEN	= 0x08,	/* transmit packet interrupt enable */
214 	IRINTR_TPKTINT	= 0x04,	/* last bit of tx-packet+crc shifted to ir-pulser */
215 	IRINTR_OE_EN	= 0x02,	/* UART rx fifo overrun error interrupt enable */
216 	IRINTR_OE_INT	= 0x01	/* UART rx fifo overrun error (read LSR to clear) */
217 };
218 
219 /* we use this mask to check whether the (shared PCI) interrupt is ours */
220 
221 #define IRINTR_INT_MASK		(IRINTR_ACTIVITY|IRINTR_RPKTINT|IRINTR_TPKTINT)
222 
223 /* ------------------------------------------ */
224 
225 /* VLSI_PIO_RINGPTR: Ring Pointer Read-Back Register (u16, ro) */
226 
227 /* _both_ ring pointers are indices relative to the _entire_ rx,tx-ring!
228  * i.e. the referenced descriptor is located
229  * at RINGBASE + PTR * sizeof(descr) for rx and tx
230  * therefore, the tx-pointer has offset MAX_RING_DESCR
231  */
232 
233 #define MAX_RING_DESCR		64	/* tx, rx rings may contain up to 64 descr each */
234 
235 #define RINGPTR_RX_MASK		(MAX_RING_DESCR-1)
236 #define RINGPTR_TX_MASK		((MAX_RING_DESCR-1)<<8)
237 
238 #define RINGPTR_GET_RX(p)	((p)&RINGPTR_RX_MASK)
239 #define RINGPTR_GET_TX(p)	(((p)&RINGPTR_TX_MASK)>>8)
240 
241 /* ------------------------------------------ */
242 
243 /* VLSI_PIO_RINGBASE: Ring Pointer Base Address Register (u16, ro) */
244 
245 /* Contains [23:10] part of the ring base (bus-) address
246  * which must be 1k-alinged. [31:24] is taken from
247  * VLSI_PCI_MSTRPAGE above.
248  * The controller initiates non-burst PCI BM cycles to
249  * fetch and update the descriptors in the ring.
250  * Once fetched, the descriptor remains cached onchip
251  * until it gets closed and updated due to the ring
252  * processing state machine.
253  * The entire ring area is split in rx and tx areas with each
254  * area consisting of 64 descriptors of 8 bytes each.
255  * The rx(tx) ring is located at ringbase+0 (ringbase+64*8).
256  */
257 
258 #define BUS_TO_RINGBASE(p)	(((p)>>10)&0x3fff)
259 
260 /* ------------------------------------------ */
261 
262 /* VLSI_PIO_RINGSIZE: Ring Size Register (u16, rw) */
263 
264 /* bit mask to indicate the ring size to be used for rx and tx.
265  * 	possible values		encoded bits
266  *		 4		   0000
267  *		 8		   0001
268  *		16		   0011
269  *		32		   0111
270  *		64		   1111
271  * located at [15:12] for tx and [11:8] for rx ([7:0] unused)
272  *
273  * note: probably a good idea to have IRCFG_MSTR cleared when writing
274  *	 this so the state machines are stopped and the RINGPTR is reset!
275  */
276 
277 #define SIZE_TO_BITS(num)		((((num)-1)>>2)&0x0f)
278 #define TX_RX_TO_RINGSIZE(tx,rx)	((SIZE_TO_BITS(tx)<<12)|(SIZE_TO_BITS(rx)<<8))
279 #define RINGSIZE_TO_RXSIZE(rs)		((((rs)&0x0f00)>>6)+4)
280 #define RINGSIZE_TO_TXSIZE(rs)		((((rs)&0xf000)>>10)+4)
281 
282 
283 /* ------------------------------------------ */
284 
285 /* VLSI_PIO_PROMPT: Ring Prompting Register (u16, write-to-start) */
286 
287 /* writing any value kicks the ring processing state machines
288  * for both tx, rx rings as follows:
289  * 	- active rings (currently owning an active descriptor)
290  *	  ignore the prompt and continue
291  *	- idle rings fetch the next descr from the ring and start
292  *	  their processing
293  */
294 
295 /* ------------------------------------------ */
296 
297 /* VLSI_PIO_IRCFG: IR Config Register (u16, rw) */
298 
299 /* notes:
300  *	- not more than one SIR/MIR/FIR bit must be set at any time
301  *	- SIR, MIR, FIR and CRC16 select the configuration which will
302  *	  be applied on next 0->1 transition of IRENABLE_PHYANDCLOCK (see below).
303  *	- besides allowing the PCI interface to execute busmaster cycles
304  *	  and therefore the ring SM to operate, the MSTR bit has side-effects:
305  *	  when MSTR is cleared, the RINGPTR's get reset and the legacy UART mode
306  *	  (in contrast to busmaster access mode) gets enabled.
307  *	- clearing ENRX or setting ENTX while data is received may stall the
308  *	  receive fifo until ENRX reenabled _and_ another packet arrives
309  *	- SIRFILT means the chip performs the required unwrapping of hardware
310  *	  headers (XBOF's, BOF/EOF) and un-escaping in the _receive_ direction.
311  *	  Only the resulting IrLAP payload is copied to the receive buffers -
312  *	  but with the 16bit FCS still encluded. Question remains, whether it
313  *	  was already checked or we should do it before passing the packet to IrLAP?
314  */
315 
316 enum vlsi_pio_ircfg {
317 	IRCFG_LOOP	= 0x4000,	/* enable loopback test mode */
318 	IRCFG_ENTX	= 0x1000,	/* transmit enable */
319 	IRCFG_ENRX	= 0x0800,	/* receive enable */
320 	IRCFG_MSTR	= 0x0400,	/* master enable */
321 	IRCFG_RXANY	= 0x0200,	/* receive any packet */
322 	IRCFG_CRC16	= 0x0080,	/* 16bit (not 32bit) CRC select for MIR/FIR */
323 	IRCFG_FIR	= 0x0040,	/* FIR 4PPM encoding mode enable */
324 	IRCFG_MIR	= 0x0020,	/* MIR HDLC encoding mode enable */
325 	IRCFG_SIR	= 0x0010,	/* SIR encoding mode enable */
326 	IRCFG_SIRFILT	= 0x0008,	/* enable SIR decode filter (receiver unwrapping) */
327 	IRCFG_SIRTEST	= 0x0004,	/* allow SIR decode filter when not in SIR mode */
328 	IRCFG_TXPOL	= 0x0002,	/* invert tx polarity when set */
329 	IRCFG_RXPOL	= 0x0001	/* invert rx polarity when set */
330 };
331 
332 /* ------------------------------------------ */
333 
334 /* VLSI_PIO_SIRFLAG: SIR Flag Register (u16, ro) */
335 
336 /* register contains hardcoded BOF=0xc0 at [7:0] and EOF=0xc1 at [15:8]
337  * which is used for unwrapping received frames in SIR decode-filter mode
338  */
339 
340 /* ------------------------------------------ */
341 
342 /* VLSI_PIO_IRENABLE: IR Enable Register (u16, rw/ro) */
343 
344 /* notes:
345  *	- IREN acts as gate for latching the configured IR mode information
346  *	  from IRCFG and IRPHYCTL when IREN=reset and applying them when
347  *	  IREN gets set afterwards.
348  *	- ENTXST reflects IRCFG_ENTX
349  *	- ENRXST = IRCFG_ENRX && (!IRCFG_ENTX || IRCFG_LOOP)
350  */
351 
352 enum vlsi_pio_irenable {
353 	IRENABLE_PHYANDCLOCK	= 0x8000,  /* enable IR phy and gate the mode config (rw) */
354 	IRENABLE_CFGER		= 0x4000,  /* mode configuration error (ro) */
355 	IRENABLE_FIR_ON		= 0x2000,  /* FIR on status (ro) */
356 	IRENABLE_MIR_ON		= 0x1000,  /* MIR on status (ro) */
357 	IRENABLE_SIR_ON		= 0x0800,  /* SIR on status (ro) */
358 	IRENABLE_ENTXST		= 0x0400,  /* transmit enable status (ro) */
359 	IRENABLE_ENRXST		= 0x0200,  /* Receive enable status (ro) */
360 	IRENABLE_CRC16_ON	= 0x0100   /* 16bit (not 32bit) CRC enabled status (ro) */
361 };
362 
363 #define	  IRENABLE_MASK	    0xff00  /* Read mask */
364 
365 /* ------------------------------------------ */
366 
367 /* VLSI_PIO_PHYCTL: IR Physical Layer Current Control Register (u16, ro) */
368 
369 /* read-back of the currently applied physical layer status.
370  * applied from VLSI_PIO_NPHYCTL at rising edge of IRENABLE_PHYANDCLOCK
371  * contents identical to VLSI_PIO_NPHYCTL (see below)
372  */
373 
374 /* ------------------------------------------ */
375 
376 /* VLSI_PIO_NPHYCTL: IR Physical Layer Next Control Register (u16, rw) */
377 
378 /* latched during IRENABLE_PHYANDCLOCK=0 and applied at 0-1 transition
379  *
380  * consists of BAUD[15:10], PLSWID[9:5] and PREAMB[4:0] bits defined as follows:
381  *
382  * SIR-mode:	BAUD = (115.2kHz / baudrate) - 1
383  *		PLSWID = (pulsetime * freq / (BAUD+1)) - 1
384  *			where pulsetime is the requested IrPHY pulse width
385  *			and freq is 8(16)MHz for 40(48)MHz primary input clock
386  *		PREAMB: don't care for SIR
387  *
388  *		The nominal SIR pulse width is 3/16 bit time so we have PLSWID=12
389  *		fixed for all SIR speeds at 40MHz input clock (PLSWID=24 at 48MHz).
390  *		IrPHY also allows shorter pulses down to the nominal pulse duration
391  *		at 115.2kbaud (minus some tolerance) which is 1.41 usec.
392  *		Using the expression PLSWID = 12/(BAUD+1)-1 (multiplied by two for 48MHz)
393  *		we get the minimum acceptable PLSWID values according to the VLSI
394  *		specification, which provides 1.5 usec pulse width for all speeds (except
395  *		for 2.4kbaud getting 6usec). This is fine with IrPHY v1.3 specs and
396  *		reduces the transceiver power which drains the battery. At 9.6kbaud for
397  *		example this amounts to more than 90% battery power saving!
398  *
399  * MIR-mode:	BAUD = 0
400  *		PLSWID = 9(10) for 40(48) MHz input clock
401  *			to get nominal MIR pulse width
402  *		PREAMB = 1
403  *
404  * FIR-mode:	BAUD = 0
405  *		PLSWID: don't care
406  *		PREAMB = 15
407  */
408 
409 #define PHYCTL_BAUD_SHIFT	10
410 #define PHYCTL_BAUD_MASK	0xfc00
411 #define PHYCTL_PLSWID_SHIFT	5
412 #define PHYCTL_PLSWID_MASK	0x03e0
413 #define PHYCTL_PREAMB_SHIFT	0
414 #define PHYCTL_PREAMB_MASK	0x001f
415 
416 #define PHYCTL_TO_BAUD(bwp)	(((bwp)&PHYCTL_BAUD_MASK)>>PHYCTL_BAUD_SHIFT)
417 #define PHYCTL_TO_PLSWID(bwp)	(((bwp)&PHYCTL_PLSWID_MASK)>>PHYCTL_PLSWID_SHIFT)
418 #define PHYCTL_TO_PREAMB(bwp)	(((bwp)&PHYCTL_PREAMB_MASK)>>PHYCTL_PREAMB_SHIFT)
419 
420 #define BWP_TO_PHYCTL(b,w,p)	((((b)<<PHYCTL_BAUD_SHIFT)&PHYCTL_BAUD_MASK) \
421 				 | (((w)<<PHYCTL_PLSWID_SHIFT)&PHYCTL_PLSWID_MASK) \
422 				 | (((p)<<PHYCTL_PREAMB_SHIFT)&PHYCTL_PREAMB_MASK))
423 
424 #define BAUD_BITS(br)		((115200/(br))-1)
425 
426 static inline unsigned
calc_width_bits(unsigned baudrate,unsigned widthselect,unsigned clockselect)427 calc_width_bits(unsigned baudrate, unsigned widthselect, unsigned clockselect)
428 {
429 	unsigned	tmp;
430 
431 	if (widthselect)	/* nominal 3/16 puls width */
432 		return (clockselect) ? 12 : 24;
433 
434 	tmp = ((clockselect) ? 12 : 24) / (BAUD_BITS(baudrate)+1);
435 
436 	/* intermediate result of integer division needed here */
437 
438 	return (tmp>0) ? (tmp-1) : 0;
439 }
440 
441 #define PHYCTL_SIR(br,ws,cs)	BWP_TO_PHYCTL(BAUD_BITS(br),calc_width_bits((br),(ws),(cs)),0)
442 #define PHYCTL_MIR(cs)		BWP_TO_PHYCTL(0,((cs)?9:10),1)
443 #define PHYCTL_FIR		BWP_TO_PHYCTL(0,0,15)
444 
445 /* quite ugly, I know. But implementing these calculations here avoids
446  * having magic numbers in the code and allows some playing with pulsewidths
447  * without risk to violate the standards.
448  * FWIW, here is the table for reference:
449  *
450  * baudrate	BAUD	min-PLSWID	nom-PLSWID	PREAMB
451  *     2400	  47	   0(0)		   12(24)	   0
452  *     9600	  11	   0(0)		   12(24)	   0
453  *    19200	   5	   1(2)		   12(24)	   0
454  *    38400	   2	   3(6)	           12(24)	   0
455  *    57600	   1	   5(10)	   12(24)	   0
456  *   115200	   0	  11(22)	   12(24)	   0
457  *	MIR	   0	    -		    9(10)	   1
458  *	FIR	   0        -               0		  15
459  *
460  * note: x(y) means x-value for 40MHz / y-value for 48MHz primary input clock
461  */
462 
463 /* ------------------------------------------ */
464 
465 
466 /* VLSI_PIO_MAXPKT: Maximum Packet Length register (u16, rw) */
467 
468 /* maximum acceptable length for received packets */
469 
470 /* hw imposed limitation - register uses only [11:0] */
471 #define MAX_PACKET_LENGTH	0x0fff
472 
473 /* IrLAP I-field (apparently not defined elsewhere) */
474 #define IRDA_MTU		2048
475 
476 /* complete packet consists of A(1)+C(1)+I(<=IRDA_MTU) */
477 #define IRLAP_SKB_ALLOCSIZE	(1+1+IRDA_MTU)
478 
479 /* the buffers we use to exchange frames with the hardware need to be
480  * larger than IRLAP_SKB_ALLOCSIZE because we may have up to 4 bytes FCS
481  * appended and, in SIR mode, a lot of frame wrapping bytes. The worst
482  * case appears to be a SIR packet with I-size==IRDA_MTU and all bytes
483  * requiring to be escaped to provide transparency. Furthermore, the peer
484  * might ask for quite a number of additional XBOFs:
485  *	up to 115+48 XBOFS		 163
486  *	regular BOF			   1
487  *	A-field				   1
488  *	C-field				   1
489  *	I-field, IRDA_MTU, all escaped	4096
490  *	FCS (16 bit at SIR, escaped)	   4
491  *	EOF				   1
492  * AFAICS nothing in IrLAP guarantees A/C field not to need escaping
493  * (f.e. 0xc0/0xc1 - i.e. BOF/EOF - are legal values there) so in the
494  * worst case we have 4269 bytes total frame size.
495  * However, the VLSI uses 12 bits only for all buffer length values,
496  * which limits the maximum useable buffer size <= 4095.
497  * Note this is not a limitation in the receive case because we use
498  * the SIR filtering mode where the hw unwraps the frame and only the
499  * bare packet+fcs is stored into the buffer - in contrast to the SIR
500  * tx case where we have to pass frame-wrapped packets to the hw.
501  * If this would ever become an issue in real life, the only workaround
502  * I see would be using the legacy UART emulation in SIR mode.
503  */
504 
505 #define XFER_BUF_SIZE		MAX_PACKET_LENGTH
506 
507 /* ------------------------------------------ */
508 
509 /* VLSI_PIO_RCVBCNT: Receive Byte Count Register (u16, ro) */
510 
511 /* receive packet counter gets incremented on every non-filtered
512  * byte which was put in the receive fifo and reset for each
513  * new packet. Used to decide whether we are just in the middle
514  * of receiving
515  */
516 
517 /* better apply the [11:0] mask when reading, as some docs say the
518  * reserved [15:12] would return 1 when reading - which is wrong AFAICS
519  */
520 #define RCVBCNT_MASK	0x0fff
521 
522 /******************************************************************/
523 
524 /* descriptors for rx/tx ring
525  *
526  * accessed by hardware - don't change!
527  *
528  * the descriptor is owned by hardware, when the ACTIVE status bit
529  * is set and nothing (besides reading status to test the bit)
530  * shall be done. The bit gets cleared by hw, when the descriptor
531  * gets closed. Premature reaping of descriptors owned be the chip
532  * can be achieved by disabling IRCFG_MSTR
533  *
534  * Attention: Writing addr overwrites status!
535  *
536  * ### FIXME: depends on endianess (but there ain't no non-i586 ob800 ;-)
537  */
538 
539 struct ring_descr_hw {
540 	volatile __le16	rd_count;	/* tx/rx count [11:0] */
541 	__le16		reserved;
542 	union {
543 		__le32	addr;		/* [23:0] of the buffer's busaddress */
544 		struct {
545 			u8		addr_res[3];
546 			volatile u8	status;		/* descriptor status */
547 		} __packed rd_s;
548 	} __packed rd_u;
549 } __packed;
550 
551 #define rd_addr		rd_u.addr
552 #define rd_status	rd_u.rd_s.status
553 
554 /* ring descriptor status bits */
555 
556 #define RD_ACTIVE		0x80	/* descriptor owned by hw (both TX,RX) */
557 
558 /* TX ring descriptor status */
559 
560 #define	RD_TX_DISCRC		0x40	/* do not send CRC (for SIR) */
561 #define	RD_TX_BADCRC		0x20	/* force a bad CRC */
562 #define	RD_TX_PULSE		0x10	/* send indication pulse after this frame (MIR/FIR) */
563 #define	RD_TX_FRCEUND		0x08	/* force underrun */
564 #define	RD_TX_CLRENTX		0x04	/* clear ENTX after this frame */
565 #define	RD_TX_UNDRN		0x01	/* TX fifo underrun (probably PCI problem) */
566 
567 /* RX ring descriptor status */
568 
569 #define RD_RX_PHYERR		0x40	/* physical encoding error */
570 #define RD_RX_CRCERR		0x20	/* CRC error (MIR/FIR) */
571 #define RD_RX_LENGTH		0x10	/* frame exceeds buffer length */
572 #define RD_RX_OVER		0x08	/* RX fifo overrun (probably PCI problem) */
573 #define RD_RX_SIRBAD		0x04	/* EOF missing: BOF follows BOF (SIR, filtered) */
574 
575 #define RD_RX_ERROR		0x7c	/* any error in received frame */
576 
577 /* the memory required to hold the 2 descriptor rings */
578 #define HW_RING_AREA_SIZE	(2 * MAX_RING_DESCR * sizeof(struct ring_descr_hw))
579 
580 /******************************************************************/
581 
582 /* sw-ring descriptors consists of a bus-mapped transfer buffer with
583  * associated skb and a pointer to the hw entry descriptor
584  */
585 
586 struct ring_descr {
587 	struct ring_descr_hw	*hw;
588 	struct sk_buff		*skb;
589 	void			*buf;
590 };
591 
592 /* wrappers for operations on hw-exposed ring descriptors
593  * access to the hw-part of the descriptors must use these.
594  */
595 
rd_is_active(struct ring_descr * rd)596 static inline int rd_is_active(struct ring_descr *rd)
597 {
598 	return (rd->hw->rd_status & RD_ACTIVE) != 0;
599 }
600 
rd_activate(struct ring_descr * rd)601 static inline void rd_activate(struct ring_descr *rd)
602 {
603 	rd->hw->rd_status |= RD_ACTIVE;
604 }
605 
rd_set_status(struct ring_descr * rd,u8 s)606 static inline void rd_set_status(struct ring_descr *rd, u8 s)
607 {
608 	rd->hw->rd_status = s;	 /* may pass ownership to the hardware */
609 }
610 
rd_set_addr_status(struct ring_descr * rd,dma_addr_t a,u8 s)611 static inline void rd_set_addr_status(struct ring_descr *rd, dma_addr_t a, u8 s)
612 {
613 	/* order is important for two reasons:
614 	 *  - overlayed: writing addr overwrites status
615 	 *  - we want to write status last so we have valid address in
616 	 *    case status has RD_ACTIVE set
617 	 */
618 
619 	if ((a & ~DMA_MASK_MSTRPAGE)>>24 != MSTRPAGE_VALUE) {
620 		IRDA_ERROR("%s: pci busaddr inconsistency!\n", __func__);
621 		dump_stack();
622 		return;
623 	}
624 
625 	a &= DMA_MASK_MSTRPAGE;  /* clear highbyte to make sure we won't write
626 				  * to status - just in case MSTRPAGE_VALUE!=0
627 				  */
628 	rd->hw->rd_addr = cpu_to_le32(a);
629 	wmb();
630 	rd_set_status(rd, s);	 /* may pass ownership to the hardware */
631 }
632 
rd_set_count(struct ring_descr * rd,u16 c)633 static inline void rd_set_count(struct ring_descr *rd, u16 c)
634 {
635 	rd->hw->rd_count = cpu_to_le16(c);
636 }
637 
rd_get_status(struct ring_descr * rd)638 static inline u8 rd_get_status(struct ring_descr *rd)
639 {
640 	return rd->hw->rd_status;
641 }
642 
rd_get_addr(struct ring_descr * rd)643 static inline dma_addr_t rd_get_addr(struct ring_descr *rd)
644 {
645 	dma_addr_t	a;
646 
647 	a = le32_to_cpu(rd->hw->rd_addr);
648 	return (a & DMA_MASK_MSTRPAGE) | (MSTRPAGE_VALUE << 24);
649 }
650 
rd_get_count(struct ring_descr * rd)651 static inline u16 rd_get_count(struct ring_descr *rd)
652 {
653 	return le16_to_cpu(rd->hw->rd_count);
654 }
655 
656 /******************************************************************/
657 
658 /* sw descriptor rings for rx, tx:
659  *
660  * operations follow producer-consumer paradigm, with the hw
661  * in the middle doing the processing.
662  * ring size must be power of two.
663  *
664  * producer advances r->tail after inserting for processing
665  * consumer advances r->head after removing processed rd
666  * ring is empty if head==tail / full if (tail+1)==head
667  */
668 
669 struct vlsi_ring {
670 	struct pci_dev		*pdev;
671 	int			dir;
672 	unsigned		len;
673 	unsigned		size;
674 	unsigned		mask;
675 	atomic_t		head, tail;
676 	struct ring_descr	*rd;
677 };
678 
679 /* ring processing helpers */
680 
ring_last(struct vlsi_ring * r)681 static inline struct ring_descr *ring_last(struct vlsi_ring *r)
682 {
683 	int t;
684 
685 	t = atomic_read(&r->tail) & r->mask;
686 	return (((t+1) & r->mask) == (atomic_read(&r->head) & r->mask)) ? NULL : &r->rd[t];
687 }
688 
ring_put(struct vlsi_ring * r)689 static inline struct ring_descr *ring_put(struct vlsi_ring *r)
690 {
691 	atomic_inc(&r->tail);
692 	return ring_last(r);
693 }
694 
ring_first(struct vlsi_ring * r)695 static inline struct ring_descr *ring_first(struct vlsi_ring *r)
696 {
697 	int h;
698 
699 	h = atomic_read(&r->head) & r->mask;
700 	return (h == (atomic_read(&r->tail) & r->mask)) ? NULL : &r->rd[h];
701 }
702 
ring_get(struct vlsi_ring * r)703 static inline struct ring_descr *ring_get(struct vlsi_ring *r)
704 {
705 	atomic_inc(&r->head);
706 	return ring_first(r);
707 }
708 
709 /******************************************************************/
710 
711 /* our private compound VLSI-PCI-IRDA device information */
712 
713 typedef struct vlsi_irda_dev {
714 	struct pci_dev		*pdev;
715 
716 	struct irlap_cb		*irlap;
717 
718 	struct qos_info		qos;
719 
720 	unsigned		mode;
721 	int			baud, new_baud;
722 
723 	dma_addr_t		busaddr;
724 	void			*virtaddr;
725 	struct vlsi_ring	*tx_ring, *rx_ring;
726 
727 	struct timeval		last_rx;
728 
729 	spinlock_t		lock;
730 	struct mutex		mtx;
731 
732 	u8			resume_ok;
733 	struct proc_dir_entry	*proc_entry;
734 
735 } vlsi_irda_dev_t;
736 
737 /********************************************************/
738 
739 /* the remapped error flags we use for returning from frame
740  * post-processing in vlsi_process_tx/rx() after it was completed
741  * by the hardware. These functions either return the >=0 number
742  * of transferred bytes in case of success or the negative (-)
743  * of the or'ed error flags.
744  */
745 
746 #define VLSI_TX_DROP		0x0001
747 #define VLSI_TX_FIFO		0x0002
748 
749 #define VLSI_RX_DROP		0x0100
750 #define VLSI_RX_OVER		0x0200
751 #define VLSI_RX_LENGTH  	0x0400
752 #define VLSI_RX_FRAME		0x0800
753 #define VLSI_RX_CRC		0x1000
754 
755 /********************************************************/
756 
757 #endif /* IRDA_VLSI_FIR_H */
758 
759