xref: /openbmc/linux/arch/m68k/include/asm/dma.h (revision a44e4f3a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _M68K_DMA_H
3 #define _M68K_DMA_H 1
4 
5 #ifdef CONFIG_COLDFIRE
6 /*
7  * ColdFire DMA Model:
8  *   ColdFire DMA supports two forms of DMA: Single and Dual address. Single
9  * address mode emits a source address, and expects that the device will either
10  * pick up the data (DMA READ) or source data (DMA WRITE). This implies that
11  * the device will place data on the correct byte(s) of the data bus, as the
12  * memory transactions are always 32 bits. This implies that only 32 bit
13  * devices will find single mode transfers useful. Dual address DMA mode
14  * performs two cycles: source read and destination write. ColdFire will
15  * align the data so that the device will always get the correct bytes, thus
16  * is useful for 8 and 16 bit devices. This is the mode that is supported
17  * below.
18  *
19  * AUG/22/2000 : added support for 32-bit Dual-Address-Mode (K) 2000
20  *               Oliver Kamphenkel (O.Kamphenkel@tu-bs.de)
21  *
22  * AUG/25/2000 : added support for 8, 16 and 32-bit Single-Address-Mode (K)2000
23  *               Oliver Kamphenkel (O.Kamphenkel@tu-bs.de)
24  *
25  * APR/18/2002 : added proper support for MCF5272 DMA controller.
26  *               Arthur Shipkowski (art@videon-central.com)
27  */
28 
29 #include <asm/coldfire.h>
30 #include <asm/mcfsim.h>
31 #include <asm/mcfdma.h>
32 
33 /*
34  * Set number of channels of DMA on ColdFire for different implementations.
35  */
36 #if defined(CONFIG_M5249) || defined(CONFIG_M5307) || defined(CONFIG_M5407) || \
37 	defined(CONFIG_M523x) || defined(CONFIG_M527x) || \
38 	defined(CONFIG_M528x) || defined(CONFIG_M525x)
39 
40 #define MAX_M68K_DMA_CHANNELS 4
41 #elif defined(CONFIG_M5272)
42 #define MAX_M68K_DMA_CHANNELS 1
43 #elif defined(CONFIG_M53xx)
44 #define MAX_M68K_DMA_CHANNELS 0
45 #else
46 #define MAX_M68K_DMA_CHANNELS 2
47 #endif
48 
49 extern unsigned int dma_base_addr[MAX_M68K_DMA_CHANNELS];
50 extern unsigned int dma_device_address[MAX_M68K_DMA_CHANNELS];
51 
52 #if !defined(CONFIG_M5272)
53 #define DMA_MODE_WRITE_BIT  0x01  /* Memory/IO to IO/Memory select */
54 #define DMA_MODE_WORD_BIT   0x02  /* 8 or 16 bit transfers */
55 #define DMA_MODE_LONG_BIT   0x04  /* or 32 bit transfers */
56 #define DMA_MODE_SINGLE_BIT 0x08  /* single-address-mode */
57 
58 /* I/O to memory, 8 bits, mode */
59 #define DMA_MODE_READ	            0
60 /* memory to I/O, 8 bits, mode */
61 #define DMA_MODE_WRITE	            1
62 /* I/O to memory, 16 bits, mode */
63 #define DMA_MODE_READ_WORD          2
64 /* memory to I/O, 16 bits, mode */
65 #define DMA_MODE_WRITE_WORD         3
66 /* I/O to memory, 32 bits, mode */
67 #define DMA_MODE_READ_LONG          4
68 /* memory to I/O, 32 bits, mode */
69 #define DMA_MODE_WRITE_LONG         5
70 /* I/O to memory, 8 bits, single-address-mode */
71 #define DMA_MODE_READ_SINGLE        8
72 /* memory to I/O, 8 bits, single-address-mode */
73 #define DMA_MODE_WRITE_SINGLE       9
74 /* I/O to memory, 16 bits, single-address-mode */
75 #define DMA_MODE_READ_WORD_SINGLE  10
76 /* memory to I/O, 16 bits, single-address-mode */
77 #define DMA_MODE_WRITE_WORD_SINGLE 11
78 /* I/O to memory, 32 bits, single-address-mode */
79 #define DMA_MODE_READ_LONG_SINGLE  12
80 /* memory to I/O, 32 bits, single-address-mode */
81 #define DMA_MODE_WRITE_LONG_SINGLE 13
82 
83 #else /* CONFIG_M5272 is defined */
84 
85 /* Source static-address mode */
86 #define DMA_MODE_SRC_SA_BIT 0x01
87 /* Two bits to select between all four modes */
88 #define DMA_MODE_SSIZE_MASK 0x06
89 /* Offset to shift bits in */
90 #define DMA_MODE_SSIZE_OFF  0x01
91 /* Destination static-address mode */
92 #define DMA_MODE_DES_SA_BIT 0x10
93 /* Two bits to select between all four modes */
94 #define DMA_MODE_DSIZE_MASK 0x60
95 /* Offset to shift bits in */
96 #define DMA_MODE_DSIZE_OFF  0x05
97 /* Size modifiers */
98 #define DMA_MODE_SIZE_LONG  0x00
99 #define DMA_MODE_SIZE_BYTE  0x01
100 #define DMA_MODE_SIZE_WORD  0x02
101 #define DMA_MODE_SIZE_LINE  0x03
102 
103 /*
104  * Aliases to help speed quick ports; these may be suboptimal, however. They
105  * do not include the SINGLE mode modifiers since the MCF5272 does not have a
106  * mode where the device is in control of its addressing.
107  */
108 
109 /* I/O to memory, 8 bits, mode */
110 #define DMA_MODE_READ	              ((DMA_MODE_SIZE_BYTE << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_BYTE << DMA_MODE_SSIZE_OFF) | DMA_SRC_SA_BIT)
111 /* memory to I/O, 8 bits, mode */
112 #define DMA_MODE_WRITE	            ((DMA_MODE_SIZE_BYTE << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_BYTE << DMA_MODE_SSIZE_OFF) | DMA_DES_SA_BIT)
113 /* I/O to memory, 16 bits, mode */
114 #define DMA_MODE_READ_WORD	        ((DMA_MODE_SIZE_WORD << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_WORD << DMA_MODE_SSIZE_OFF) | DMA_SRC_SA_BIT)
115 /* memory to I/O, 16 bits, mode */
116 #define DMA_MODE_WRITE_WORD         ((DMA_MODE_SIZE_WORD << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_WORD << DMA_MODE_SSIZE_OFF) | DMA_DES_SA_BIT)
117 /* I/O to memory, 32 bits, mode */
118 #define DMA_MODE_READ_LONG	        ((DMA_MODE_SIZE_LONG << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_LONG << DMA_MODE_SSIZE_OFF) | DMA_SRC_SA_BIT)
119 /* memory to I/O, 32 bits, mode */
120 #define DMA_MODE_WRITE_LONG         ((DMA_MODE_SIZE_LONG << DMA_MODE_DSIZE_OFF) | (DMA_MODE_SIZE_LONG << DMA_MODE_SSIZE_OFF) | DMA_DES_SA_BIT)
121 
122 #endif /* !defined(CONFIG_M5272) */
123 
124 #if !defined(CONFIG_M5272)
125 /* enable/disable a specific DMA channel */
126 static __inline__ void enable_dma(unsigned int dmanr)
127 {
128   volatile unsigned short *dmawp;
129 
130 #ifdef DMA_DEBUG
131   printk("enable_dma(dmanr=%d)\n", dmanr);
132 #endif
133 
134   dmawp = (unsigned short *) dma_base_addr[dmanr];
135   dmawp[MCFDMA_DCR] |= MCFDMA_DCR_EEXT;
136 }
137 
138 static __inline__ void disable_dma(unsigned int dmanr)
139 {
140   volatile unsigned short *dmawp;
141   volatile unsigned char  *dmapb;
142 
143 #ifdef DMA_DEBUG
144   printk("disable_dma(dmanr=%d)\n", dmanr);
145 #endif
146 
147   dmawp = (unsigned short *) dma_base_addr[dmanr];
148   dmapb = (unsigned char *) dma_base_addr[dmanr];
149 
150   /* Turn off external requests, and stop any DMA in progress */
151   dmawp[MCFDMA_DCR] &= ~MCFDMA_DCR_EEXT;
152   dmapb[MCFDMA_DSR] = MCFDMA_DSR_DONE;
153 }
154 
155 /*
156  * Clear the 'DMA Pointer Flip Flop'.
157  * Write 0 for LSB/MSB, 1 for MSB/LSB access.
158  * Use this once to initialize the FF to a known state.
159  * After that, keep track of it. :-)
160  * --- In order to do that, the DMA routines below should ---
161  * --- only be used while interrupts are disabled! ---
162  *
163  * This is a NOP for ColdFire. Provide a stub for compatibility.
164  */
165 static __inline__ void clear_dma_ff(unsigned int dmanr)
166 {
167 }
168 
169 /* set mode (above) for a specific DMA channel */
170 static __inline__ void set_dma_mode(unsigned int dmanr, char mode)
171 {
172 
173   volatile unsigned char  *dmabp;
174   volatile unsigned short *dmawp;
175 
176 #ifdef DMA_DEBUG
177   printk("set_dma_mode(dmanr=%d,mode=%d)\n", dmanr, mode);
178 #endif
179 
180   dmabp = (unsigned char *) dma_base_addr[dmanr];
181   dmawp = (unsigned short *) dma_base_addr[dmanr];
182 
183   /* Clear config errors */
184   dmabp[MCFDMA_DSR] = MCFDMA_DSR_DONE;
185 
186   /* Set command register */
187   dmawp[MCFDMA_DCR] =
188     MCFDMA_DCR_INT |         /* Enable completion irq */
189     MCFDMA_DCR_CS |          /* Force one xfer per request */
190     MCFDMA_DCR_AA |          /* Enable auto alignment */
191     /* single-address-mode */
192     ((mode & DMA_MODE_SINGLE_BIT) ? MCFDMA_DCR_SAA : 0) |
193     /* sets s_rw (-> r/w) high if Memory to I/0 */
194     ((mode & DMA_MODE_WRITE_BIT) ? MCFDMA_DCR_S_RW : 0) |
195     /* Memory to I/O or I/O to Memory */
196     ((mode & DMA_MODE_WRITE_BIT) ? MCFDMA_DCR_SINC : MCFDMA_DCR_DINC) |
197     /* 32 bit, 16 bit or 8 bit transfers */
198     ((mode & DMA_MODE_WORD_BIT)  ? MCFDMA_DCR_SSIZE_WORD :
199      ((mode & DMA_MODE_LONG_BIT) ? MCFDMA_DCR_SSIZE_LONG :
200                                    MCFDMA_DCR_SSIZE_BYTE)) |
201     ((mode & DMA_MODE_WORD_BIT)  ? MCFDMA_DCR_DSIZE_WORD :
202      ((mode & DMA_MODE_LONG_BIT) ? MCFDMA_DCR_DSIZE_LONG :
203                                    MCFDMA_DCR_DSIZE_BYTE));
204 
205 #ifdef DEBUG_DMA
206   printk("%s(%d): dmanr=%d DSR[%x]=%x DCR[%x]=%x\n", __FILE__, __LINE__,
207          dmanr, (int) &dmabp[MCFDMA_DSR], dmabp[MCFDMA_DSR],
208 	 (int) &dmawp[MCFDMA_DCR], dmawp[MCFDMA_DCR]);
209 #endif
210 }
211 
212 /* Set transfer address for specific DMA channel */
213 static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a)
214 {
215   volatile unsigned short *dmawp;
216   volatile unsigned int   *dmalp;
217 
218 #ifdef DMA_DEBUG
219   printk("set_dma_addr(dmanr=%d,a=%x)\n", dmanr, a);
220 #endif
221 
222   dmawp = (unsigned short *) dma_base_addr[dmanr];
223   dmalp = (unsigned int *) dma_base_addr[dmanr];
224 
225   /* Determine which address registers are used for memory/device accesses */
226   if (dmawp[MCFDMA_DCR] & MCFDMA_DCR_SINC) {
227     /* Source incrementing, must be memory */
228     dmalp[MCFDMA_SAR] = a;
229     /* Set dest address, must be device */
230     dmalp[MCFDMA_DAR] = dma_device_address[dmanr];
231   } else {
232     /* Destination incrementing, must be memory */
233     dmalp[MCFDMA_DAR] = a;
234     /* Set source address, must be device */
235     dmalp[MCFDMA_SAR] = dma_device_address[dmanr];
236   }
237 
238 #ifdef DEBUG_DMA
239   printk("%s(%d): dmanr=%d DCR[%x]=%x SAR[%x]=%08x DAR[%x]=%08x\n",
240 	__FILE__, __LINE__, dmanr, (int) &dmawp[MCFDMA_DCR], dmawp[MCFDMA_DCR],
241 	(int) &dmalp[MCFDMA_SAR], dmalp[MCFDMA_SAR],
242 	(int) &dmalp[MCFDMA_DAR], dmalp[MCFDMA_DAR]);
243 #endif
244 }
245 
246 /*
247  * Specific for Coldfire - sets device address.
248  * Should be called after the mode set call, and before set DMA address.
249  */
250 static __inline__ void set_dma_device_addr(unsigned int dmanr, unsigned int a)
251 {
252 #ifdef DMA_DEBUG
253   printk("set_dma_device_addr(dmanr=%d,a=%x)\n", dmanr, a);
254 #endif
255 
256   dma_device_address[dmanr] = a;
257 }
258 
259 /*
260  * NOTE 2: "count" represents _bytes_.
261  */
262 static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count)
263 {
264   volatile unsigned short *dmawp;
265 
266 #ifdef DMA_DEBUG
267   printk("set_dma_count(dmanr=%d,count=%d)\n", dmanr, count);
268 #endif
269 
270   dmawp = (unsigned short *) dma_base_addr[dmanr];
271   dmawp[MCFDMA_BCR] = (unsigned short)count;
272 }
273 
274 /*
275  * Get DMA residue count. After a DMA transfer, this
276  * should return zero. Reading this while a DMA transfer is
277  * still in progress will return unpredictable results.
278  * Otherwise, it returns the number of _bytes_ left to transfer.
279  */
280 static __inline__ int get_dma_residue(unsigned int dmanr)
281 {
282   volatile unsigned short *dmawp;
283   unsigned short count;
284 
285 #ifdef DMA_DEBUG
286   printk("get_dma_residue(dmanr=%d)\n", dmanr);
287 #endif
288 
289   dmawp = (unsigned short *) dma_base_addr[dmanr];
290   count = dmawp[MCFDMA_BCR];
291   return((int) count);
292 }
293 #else /* CONFIG_M5272 is defined */
294 
295 /*
296  * The MCF5272 DMA controller is very different than the controller defined above
297  * in terms of register mapping.  For instance, with the exception of the 16-bit
298  * interrupt register (IRQ#85, for reference), all of the registers are 32-bit.
299  *
300  * The big difference, however, is the lack of device-requested DMA.  All modes
301  * are dual address transfer, and there is no 'device' setup or direction bit.
302  * You can DMA between a device and memory, between memory and memory, or even between
303  * two devices directly, with any combination of incrementing and non-incrementing
304  * addresses you choose.  This puts a crimp in distinguishing between the 'device
305  * address' set up by set_dma_device_addr.
306  *
307  * Therefore, there are two options.  One is to use set_dma_addr and set_dma_device_addr,
308  * which will act exactly as above in -- it will look to see if the source is set to
309  * autoincrement, and if so it will make the source use the set_dma_addr value and the
310  * destination the set_dma_device_addr value.  Otherwise the source will be set to the
311  * set_dma_device_addr value and the destination will get the set_dma_addr value.
312  *
313  * The other is to use the provided set_dma_src_addr and set_dma_dest_addr functions
314  * and make it explicit.  Depending on what you're doing, one of these two should work
315  * for you, but don't mix them in the same transfer setup.
316  */
317 
318 /* enable/disable a specific DMA channel */
319 static __inline__ void enable_dma(unsigned int dmanr)
320 {
321   volatile unsigned int  *dmalp;
322 
323 #ifdef DMA_DEBUG
324   printk("enable_dma(dmanr=%d)\n", dmanr);
325 #endif
326 
327   dmalp = (unsigned int *) dma_base_addr[dmanr];
328   dmalp[MCFDMA_DMR] |= MCFDMA_DMR_EN;
329 }
330 
331 static __inline__ void disable_dma(unsigned int dmanr)
332 {
333   volatile unsigned int   *dmalp;
334 
335 #ifdef DMA_DEBUG
336   printk("disable_dma(dmanr=%d)\n", dmanr);
337 #endif
338 
339   dmalp = (unsigned int *) dma_base_addr[dmanr];
340 
341   /* Turn off external requests, and stop any DMA in progress */
342   dmalp[MCFDMA_DMR] &= ~MCFDMA_DMR_EN;
343   dmalp[MCFDMA_DMR] |= MCFDMA_DMR_RESET;
344 }
345 
346 /*
347  * Clear the 'DMA Pointer Flip Flop'.
348  * Write 0 for LSB/MSB, 1 for MSB/LSB access.
349  * Use this once to initialize the FF to a known state.
350  * After that, keep track of it. :-)
351  * --- In order to do that, the DMA routines below should ---
352  * --- only be used while interrupts are disabled! ---
353  *
354  * This is a NOP for ColdFire. Provide a stub for compatibility.
355  */
356 static __inline__ void clear_dma_ff(unsigned int dmanr)
357 {
358 }
359 
360 /* set mode (above) for a specific DMA channel */
361 static __inline__ void set_dma_mode(unsigned int dmanr, char mode)
362 {
363 
364   volatile unsigned int   *dmalp;
365   volatile unsigned short *dmawp;
366 
367 #ifdef DMA_DEBUG
368   printk("set_dma_mode(dmanr=%d,mode=%d)\n", dmanr, mode);
369 #endif
370   dmalp = (unsigned int *) dma_base_addr[dmanr];
371   dmawp = (unsigned short *) dma_base_addr[dmanr];
372 
373   /* Clear config errors */
374   dmalp[MCFDMA_DMR] |= MCFDMA_DMR_RESET;
375 
376   /* Set command register */
377   dmalp[MCFDMA_DMR] =
378     MCFDMA_DMR_RQM_DUAL |         /* Mandatory Request Mode setting */
379     MCFDMA_DMR_DSTT_SD  |         /* Set up addressing types; set to supervisor-data. */
380     MCFDMA_DMR_SRCT_SD  |         /* Set up addressing types; set to supervisor-data. */
381     /* source static-address-mode */
382     ((mode & DMA_MODE_SRC_SA_BIT) ? MCFDMA_DMR_SRCM_SA : MCFDMA_DMR_SRCM_IA) |
383     /* dest static-address-mode */
384     ((mode & DMA_MODE_DES_SA_BIT) ? MCFDMA_DMR_DSTM_SA : MCFDMA_DMR_DSTM_IA) |
385     /* burst, 32 bit, 16 bit or 8 bit transfers are separately configurable on the MCF5272 */
386     (((mode & DMA_MODE_SSIZE_MASK) >> DMA_MODE_SSIZE_OFF) << MCFDMA_DMR_DSTS_OFF) |
387     (((mode & DMA_MODE_SSIZE_MASK) >> DMA_MODE_SSIZE_OFF) << MCFDMA_DMR_SRCS_OFF);
388 
389   dmawp[MCFDMA_DIR] |= MCFDMA_DIR_ASCEN;   /* Enable completion interrupts */
390 
391 #ifdef DEBUG_DMA
392   printk("%s(%d): dmanr=%d DMR[%x]=%x DIR[%x]=%x\n", __FILE__, __LINE__,
393 	 dmanr, (int) &dmalp[MCFDMA_DMR], dmalp[MCFDMA_DMR],
394 	 (int) &dmawp[MCFDMA_DIR], dmawp[MCFDMA_DIR]);
395 #endif
396 }
397 
398 /* Set transfer address for specific DMA channel */
399 static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a)
400 {
401   volatile unsigned int   *dmalp;
402 
403 #ifdef DMA_DEBUG
404   printk("set_dma_addr(dmanr=%d,a=%x)\n", dmanr, a);
405 #endif
406 
407   dmalp = (unsigned int *) dma_base_addr[dmanr];
408 
409   /* Determine which address registers are used for memory/device accesses */
410   if (dmalp[MCFDMA_DMR] & MCFDMA_DMR_SRCM) {
411     /* Source incrementing, must be memory */
412     dmalp[MCFDMA_DSAR] = a;
413     /* Set dest address, must be device */
414     dmalp[MCFDMA_DDAR] = dma_device_address[dmanr];
415   } else {
416     /* Destination incrementing, must be memory */
417     dmalp[MCFDMA_DDAR] = a;
418     /* Set source address, must be device */
419     dmalp[MCFDMA_DSAR] = dma_device_address[dmanr];
420   }
421 
422 #ifdef DEBUG_DMA
423   printk("%s(%d): dmanr=%d DMR[%x]=%x SAR[%x]=%08x DAR[%x]=%08x\n",
424 	__FILE__, __LINE__, dmanr, (int) &dmalp[MCFDMA_DMR], dmalp[MCFDMA_DMR],
425 	(int) &dmalp[MCFDMA_DSAR], dmalp[MCFDMA_DSAR],
426 	(int) &dmalp[MCFDMA_DDAR], dmalp[MCFDMA_DDAR]);
427 #endif
428 }
429 
430 /*
431  * Specific for Coldfire - sets device address.
432  * Should be called after the mode set call, and before set DMA address.
433  */
434 static __inline__ void set_dma_device_addr(unsigned int dmanr, unsigned int a)
435 {
436 #ifdef DMA_DEBUG
437   printk("set_dma_device_addr(dmanr=%d,a=%x)\n", dmanr, a);
438 #endif
439 
440   dma_device_address[dmanr] = a;
441 }
442 
443 /*
444  * NOTE 2: "count" represents _bytes_.
445  *
446  * NOTE 3: While a 32-bit register, "count" is only a maximum 24-bit value.
447  */
448 static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count)
449 {
450   volatile unsigned int *dmalp;
451 
452 #ifdef DMA_DEBUG
453   printk("set_dma_count(dmanr=%d,count=%d)\n", dmanr, count);
454 #endif
455 
456   dmalp = (unsigned int *) dma_base_addr[dmanr];
457   dmalp[MCFDMA_DBCR] = count;
458 }
459 
460 /*
461  * Get DMA residue count. After a DMA transfer, this
462  * should return zero. Reading this while a DMA transfer is
463  * still in progress will return unpredictable results.
464  * Otherwise, it returns the number of _bytes_ left to transfer.
465  */
466 static __inline__ int get_dma_residue(unsigned int dmanr)
467 {
468   volatile unsigned int *dmalp;
469   unsigned int count;
470 
471 #ifdef DMA_DEBUG
472   printk("get_dma_residue(dmanr=%d)\n", dmanr);
473 #endif
474 
475   dmalp = (unsigned int *) dma_base_addr[dmanr];
476   count = dmalp[MCFDMA_DBCR];
477   return(count);
478 }
479 
480 #endif /* !defined(CONFIG_M5272) */
481 #endif /* CONFIG_COLDFIRE */
482 
483 /* it's useless on the m68k, but unfortunately needed by the new
484    bootmem allocator (but this should do it for this) */
485 #define MAX_DMA_ADDRESS PAGE_OFFSET
486 
487 #define MAX_DMA_CHANNELS 8
488 
489 extern int request_dma(unsigned int dmanr, const char * device_id);	/* reserve a DMA channel */
490 extern void free_dma(unsigned int dmanr);	/* release it again */
491 
492 #ifdef CONFIG_PCI
493 extern int isa_dma_bridge_buggy;
494 #else
495 #define isa_dma_bridge_buggy    (0)
496 #endif
497 
498 #endif /* _M68K_DMA_H */
499