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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * include/asm-ppc/dma.h: Defines for using and allocating dma channels.
3 * Written by Hennus Bergman, 1992.
4 * High DMA channel support & info by Hannu Savolainen
5 * and John Boyd, Nov. 1992.
6 * Changes for ppc sound by Christoph Nadig
7 */
8
9#ifdef __KERNEL__
10
11#include <linux/config.h>
12#include <asm/io.h>
13#include <linux/spinlock.h>
14#include <asm/system.h>
15
16/*
17 * Note: Adapted for PowerPC by Gary Thomas
18 * Modified by Cort Dougan <cort@cs.nmt.edu>
19 *
20 * None of this really applies for Power Macintoshes. There is
21 * basically just enough here to get kernel/dma.c to compile.
22 *
23 * There may be some comments or restrictions made here which are
24 * not valid for the PReP platform. Take what you read
25 * with a grain of salt.
26 */
27
28#ifndef _ASM_DMA_H
29#define _ASM_DMA_H
30
31#ifndef MAX_DMA_CHANNELS
32#define MAX_DMA_CHANNELS 8
33#endif
34
35/* The maximum address that we can perform a DMA transfer to on this platform */
36/* Doesn't really apply... */
37#define MAX_DMA_ADDRESS 0xFFFFFFFF
38
39/* in arch/ppc/kernel/setup.c -- Cort */
40extern unsigned long DMA_MODE_WRITE, DMA_MODE_READ;
41extern unsigned long ISA_DMA_THRESHOLD;
42
43#ifdef HAVE_REALLY_SLOW_DMA_CONTROLLER
44#define dma_outb outb_p
45#else
46#define dma_outb outb
47#endif
48
49#define dma_inb inb
50
51/*
52 * NOTES about DMA transfers:
53 *
54 * controller 1: channels 0-3, byte operations, ports 00-1F
55 * controller 2: channels 4-7, word operations, ports C0-DF
56 *
57 * - ALL registers are 8 bits only, regardless of transfer size
58 * - channel 4 is not used - cascades 1 into 2.
59 * - channels 0-3 are byte - addresses/counts are for physical bytes
60 * - channels 5-7 are word - addresses/counts are for physical words
61 * - transfers must not cross physical 64K (0-3) or 128K (5-7) boundaries
62 * - transfer count loaded to registers is 1 less than actual count
63 * - controller 2 offsets are all even (2x offsets for controller 1)
64 * - page registers for 5-7 don't use data bit 0, represent 128K pages
65 * - page registers for 0-3 use bit 0, represent 64K pages
66 *
67 * On PReP, DMA transfers are limited to the lower 16MB of _physical_ memory.
68 * On CHRP, the W83C553F (and VLSI Tollgate?) support full 32 bit addressing.
69 * Note that addresses loaded into registers must be _physical_ addresses,
70 * not logical addresses (which may differ if paging is active).
71 *
72 * Address mapping for channels 0-3:
73 *
74 * A23 ... A16 A15 ... A8 A7 ... A0 (Physical addresses)
75 * | ... | | ... | | ... |
76 * | ... | | ... | | ... |
77 * | ... | | ... | | ... |
78 * P7 ... P0 A7 ... A0 A7 ... A0
79 * | Page | Addr MSB | Addr LSB | (DMA registers)
80 *
81 * Address mapping for channels 5-7:
82 *
83 * A23 ... A17 A16 A15 ... A9 A8 A7 ... A1 A0 (Physical addresses)
84 * | ... | \ \ ... \ \ \ ... \ \
85 * | ... | \ \ ... \ \ \ ... \ (not used)
86 * | ... | \ \ ... \ \ \ ... \
87 * P7 ... P1 (0) A7 A6 ... A0 A7 A6 ... A0
88 * | Page | Addr MSB | Addr LSB | (DMA registers)
89 *
90 * Again, channels 5-7 transfer _physical_ words (16 bits), so addresses
91 * and counts _must_ be word-aligned (the lowest address bit is _ignored_ at
92 * the hardware level, so odd-byte transfers aren't possible).
93 *
94 * Transfer count (_not # bytes_) is limited to 64K, represented as actual
95 * count - 1 : 64K => 0xFFFF, 1 => 0x0000. Thus, count is always 1 or more,
96 * and up to 128K bytes may be transferred on channels 5-7 in one operation.
97 *
98 */
99
100/* see prep_setup_arch() for detailed informations */
101#if defined(CONFIG_SOUND_CS4232) && defined(CONFIG_PPC_PREP)
102extern long ppc_cs4232_dma, ppc_cs4232_dma2;
103#define SND_DMA1 ppc_cs4232_dma
104#define SND_DMA2 ppc_cs4232_dma2
105#else
106#define SND_DMA1 -1
107#define SND_DMA2 -1
108#endif
109
110/* 8237 DMA controllers */
111#define IO_DMA1_BASE 0x00 /* 8 bit slave DMA, channels 0..3 */
112#define IO_DMA2_BASE 0xC0 /* 16 bit master DMA, ch 4(=slave input)..7 */
113
114/* DMA controller registers */
115#define DMA1_CMD_REG 0x08 /* command register (w) */
116#define DMA1_STAT_REG 0x08 /* status register (r) */
117#define DMA1_REQ_REG 0x09 /* request register (w) */
118#define DMA1_MASK_REG 0x0A /* single-channel mask (w) */
119#define DMA1_MODE_REG 0x0B /* mode register (w) */
120#define DMA1_CLEAR_FF_REG 0x0C /* clear pointer flip-flop (w) */
121#define DMA1_TEMP_REG 0x0D /* Temporary Register (r) */
122#define DMA1_RESET_REG 0x0D /* Master Clear (w) */
123#define DMA1_CLR_MASK_REG 0x0E /* Clear Mask */
124#define DMA1_MASK_ALL_REG 0x0F /* all-channels mask (w) */
125
126#define DMA2_CMD_REG 0xD0 /* command register (w) */
127#define DMA2_STAT_REG 0xD0 /* status register (r) */
128#define DMA2_REQ_REG 0xD2 /* request register (w) */
129#define DMA2_MASK_REG 0xD4 /* single-channel mask (w) */
130#define DMA2_MODE_REG 0xD6 /* mode register (w) */
131#define DMA2_CLEAR_FF_REG 0xD8 /* clear pointer flip-flop (w) */
132#define DMA2_TEMP_REG 0xDA /* Temporary Register (r) */
133#define DMA2_RESET_REG 0xDA /* Master Clear (w) */
134#define DMA2_CLR_MASK_REG 0xDC /* Clear Mask */
135#define DMA2_MASK_ALL_REG 0xDE /* all-channels mask (w) */
136
137#define DMA_ADDR_0 0x00 /* DMA address registers */
138#define DMA_ADDR_1 0x02
139#define DMA_ADDR_2 0x04
140#define DMA_ADDR_3 0x06
141#define DMA_ADDR_4 0xC0
142#define DMA_ADDR_5 0xC4
143#define DMA_ADDR_6 0xC8
144#define DMA_ADDR_7 0xCC
145
146#define DMA_CNT_0 0x01 /* DMA count registers */
147#define DMA_CNT_1 0x03
148#define DMA_CNT_2 0x05
149#define DMA_CNT_3 0x07
150#define DMA_CNT_4 0xC2
151#define DMA_CNT_5 0xC6
152#define DMA_CNT_6 0xCA
153#define DMA_CNT_7 0xCE
154
155#define DMA_LO_PAGE_0 0x87 /* DMA page registers */
156#define DMA_LO_PAGE_1 0x83
157#define DMA_LO_PAGE_2 0x81
158#define DMA_LO_PAGE_3 0x82
159#define DMA_LO_PAGE_5 0x8B
160#define DMA_LO_PAGE_6 0x89
161#define DMA_LO_PAGE_7 0x8A
162
163#define DMA_HI_PAGE_0 0x487 /* DMA page registers */
164#define DMA_HI_PAGE_1 0x483
165#define DMA_HI_PAGE_2 0x481
166#define DMA_HI_PAGE_3 0x482
167#define DMA_HI_PAGE_5 0x48B
168#define DMA_HI_PAGE_6 0x489
169#define DMA_HI_PAGE_7 0x48A
170
171#define DMA1_EXT_REG 0x40B
172#define DMA2_EXT_REG 0x4D6
173
174#define DMA_MODE_CASCADE 0xC0 /* pass thru DREQ->HRQ, DACK<-HLDA only */
175#define DMA_AUTOINIT 0x10
176
177extern spinlock_t dma_spin_lock;
178
179static __inline__ unsigned long claim_dma_lock(void)
180{
181 unsigned long flags;
182 spin_lock_irqsave(&dma_spin_lock, flags);
183 return flags;
184}
185
186static __inline__ void release_dma_lock(unsigned long flags)
187{
188 spin_unlock_irqrestore(&dma_spin_lock, flags);
189}
190
191/* enable/disable a specific DMA channel */
192static __inline__ void enable_dma(unsigned int dmanr)
193{
194 unsigned char ucDmaCmd = 0x00;
195
196 if (dmanr != 4) {
197 dma_outb(0, DMA2_MASK_REG); /* This may not be enabled */
198 dma_outb(ucDmaCmd, DMA2_CMD_REG); /* Enable group */
199 }
200 if (dmanr <= 3) {
201 dma_outb(dmanr, DMA1_MASK_REG);
202 dma_outb(ucDmaCmd, DMA1_CMD_REG); /* Enable group */
203 } else
204 dma_outb(dmanr & 3, DMA2_MASK_REG);
205}
206
207static __inline__ void disable_dma(unsigned int dmanr)
208{
209 if (dmanr <= 3)
210 dma_outb(dmanr | 4, DMA1_MASK_REG);
211 else
212 dma_outb((dmanr & 3) | 4, DMA2_MASK_REG);
213}
214
215/* Clear the 'DMA Pointer Flip Flop'.
216 * Write 0 for LSB/MSB, 1 for MSB/LSB access.
217 * Use this once to initialize the FF to a known state.
218 * After that, keep track of it. :-)
219 * --- In order to do that, the DMA routines below should ---
220 * --- only be used while interrupts are disabled! ---
221 */
222static __inline__ void clear_dma_ff(unsigned int dmanr)
223{
224 if (dmanr <= 3)
225 dma_outb(0, DMA1_CLEAR_FF_REG);
226 else
227 dma_outb(0, DMA2_CLEAR_FF_REG);
228}
229
230/* set mode (above) for a specific DMA channel */
231static __inline__ void set_dma_mode(unsigned int dmanr, char mode)
232{
233 if (dmanr <= 3)
234 dma_outb(mode | dmanr, DMA1_MODE_REG);
235 else
236 dma_outb(mode | (dmanr & 3), DMA2_MODE_REG);
237}
238
239/* Set only the page register bits of the transfer address.
240 * This is used for successive transfers when we know the contents of
241 * the lower 16 bits of the DMA current address register, but a 64k boundary
242 * may have been crossed.
243 */
244static __inline__ void set_dma_page(unsigned int dmanr, int pagenr)
245{
246 switch (dmanr) {
247 case 0:
248 dma_outb(pagenr, DMA_LO_PAGE_0);
249 dma_outb(pagenr >> 8, DMA_HI_PAGE_0);
250 break;
251 case 1:
252 dma_outb(pagenr, DMA_LO_PAGE_1);
253 dma_outb(pagenr >> 8, DMA_HI_PAGE_1);
254 break;
255 case 2:
256 dma_outb(pagenr, DMA_LO_PAGE_2);
257 dma_outb(pagenr >> 8, DMA_HI_PAGE_2);
258 break;
259 case 3:
260 dma_outb(pagenr, DMA_LO_PAGE_3);
261 dma_outb(pagenr >> 8, DMA_HI_PAGE_3);
262 break;
263 case 5:
264 if (SND_DMA1 == 5 || SND_DMA2 == 5)
265 dma_outb(pagenr, DMA_LO_PAGE_5);
266 else
267 dma_outb(pagenr & 0xfe, DMA_LO_PAGE_5);
268 dma_outb(pagenr >> 8, DMA_HI_PAGE_5);
269 break;
270 case 6:
271 if (SND_DMA1 == 6 || SND_DMA2 == 6)
272 dma_outb(pagenr, DMA_LO_PAGE_6);
273 else
274 dma_outb(pagenr & 0xfe, DMA_LO_PAGE_6);
275 dma_outb(pagenr >> 8, DMA_HI_PAGE_6);
276 break;
277 case 7:
278 if (SND_DMA1 == 7 || SND_DMA2 == 7)
279 dma_outb(pagenr, DMA_LO_PAGE_7);
280 else
281 dma_outb(pagenr & 0xfe, DMA_LO_PAGE_7);
282 dma_outb(pagenr >> 8, DMA_HI_PAGE_7);
283 break;
284 }
285}
286
287/* Set transfer address & page bits for specific DMA channel.
288 * Assumes dma flipflop is clear.
289 */
290static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int phys)
291{
292 if (dmanr <= 3) {
293 dma_outb(phys & 0xff, ((dmanr & 3) << 1) + IO_DMA1_BASE);
294 dma_outb((phys >> 8) & 0xff, ((dmanr & 3) << 1) + IO_DMA1_BASE);
295 } else if (dmanr == SND_DMA1 || dmanr == SND_DMA2) {
296 dma_outb(phys & 0xff, ((dmanr & 3) << 2) + IO_DMA2_BASE);
297 dma_outb((phys >> 8) & 0xff, ((dmanr & 3) << 2) + IO_DMA2_BASE);
298 dma_outb((dmanr & 3), DMA2_EXT_REG);
299 } else {
300 dma_outb((phys >> 1) & 0xff, ((dmanr & 3) << 2) + IO_DMA2_BASE);
301 dma_outb((phys >> 9) & 0xff, ((dmanr & 3) << 2) + IO_DMA2_BASE);
302 }
303 set_dma_page(dmanr, phys >> 16);
304}
305
306/* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for
307 * a specific DMA channel.
308 * You must ensure the parameters are valid.
309 * NOTE: from a manual: "the number of transfers is one more
310 * than the initial word count"! This is taken into account.
311 * Assumes dma flip-flop is clear.
312 * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7.
313 */
314static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count)
315{
316 count--;
317 if (dmanr <= 3) {
318 dma_outb(count & 0xff, ((dmanr & 3) << 1) + 1 + IO_DMA1_BASE);
319 dma_outb((count >> 8) & 0xff, ((dmanr & 3) << 1) + 1 +
320 IO_DMA1_BASE);
321 } else if (dmanr == SND_DMA1 || dmanr == SND_DMA2) {
322 dma_outb(count & 0xff, ((dmanr & 3) << 2) + 2 + IO_DMA2_BASE);
323 dma_outb((count >> 8) & 0xff, ((dmanr & 3) << 2) + 2 +
324 IO_DMA2_BASE);
325 } else {
326 dma_outb((count >> 1) & 0xff, ((dmanr & 3) << 2) + 2 +
327 IO_DMA2_BASE);
328 dma_outb((count >> 9) & 0xff, ((dmanr & 3) << 2) + 2 +
329 IO_DMA2_BASE);
330 }
331}
332
333/* Get DMA residue count. After a DMA transfer, this
334 * should return zero. Reading this while a DMA transfer is
335 * still in progress will return unpredictable results.
336 * If called before the channel has been used, it may return 1.
337 * Otherwise, it returns the number of _bytes_ left to transfer.
338 *
339 * Assumes DMA flip-flop is clear.
340 */
341static __inline__ int get_dma_residue(unsigned int dmanr)
342{
343 unsigned int io_port = (dmanr <= 3) ?
344 ((dmanr & 3) << 1) + 1 + IO_DMA1_BASE
345 : ((dmanr & 3) << 2) + 2 + IO_DMA2_BASE;
346
347 /* using short to get 16-bit wrap around */
348 unsigned short count;
349
350 count = 1 + dma_inb(io_port);
351 count += dma_inb(io_port) << 8;
352
353 return (dmanr <= 3 || dmanr == SND_DMA1 || dmanr == SND_DMA2)
354 ? count : (count << 1);
355
356}
357
358/* These are in kernel/dma.c: */
359
360/* reserve a DMA channel */
361extern int request_dma(unsigned int dmanr, const char *device_id);
362/* release it again */
363extern void free_dma(unsigned int dmanr);
364
365#ifdef CONFIG_PCI
366extern int isa_dma_bridge_buggy;
367#else
368#define isa_dma_bridge_buggy (0)
369#endif
370#endif /* _ASM_DMA_H */
371#endif /* __KERNEL__ */