1 /*
2  * BRIEF MODULE DESCRIPTION
3  *	Defines for using and allocating DMA channels on the Alchemy
4  *      Au1x00 MIPS processors.
5  *
6  * Copyright 2000, 2008 MontaVista Software Inc.
7  * Author: MontaVista Software, Inc. <source@mvista.com>
8  *
9  *  This program is free software; you can redistribute  it and/or modify it
10  *  under  the terms of  the GNU General  Public License as published by the
11  *  Free Software Foundation;  either version 2 of the  License, or (at your
12  *  option) any later version.
13  *
14  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
15  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
16  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
17  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
18  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
20  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
21  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
22  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  *
25  *  You should have received a copy of the  GNU General Public License along
26  *  with this program; if not, write  to the Free Software Foundation, Inc.,
27  *  675 Mass Ave, Cambridge, MA 02139, USA.
28  *
29  */
30 #ifndef __ASM_AU1000_DMA_H
31 #define __ASM_AU1000_DMA_H
32 
33 #include <linux/io.h>		/* need byte IO */
34 #include <linux/spinlock.h>	/* And spinlocks */
35 #include <linux/delay.h>
36 
37 #define NUM_AU1000_DMA_CHANNELS	8
38 
39 /* DMA Channel Register Offsets */
40 #define DMA_MODE_SET		0x00000000
41 #define DMA_MODE_READ		DMA_MODE_SET
42 #define DMA_MODE_CLEAR		0x00000004
43 /* DMA Mode register bits follow */
44 #define DMA_DAH_MASK		(0x0f << 20)
45 #define DMA_DID_BIT		16
46 #define DMA_DID_MASK		(0x0f << DMA_DID_BIT)
47 #define DMA_DS			(1 << 15)
48 #define DMA_BE			(1 << 13)
49 #define DMA_DR			(1 << 12)
50 #define DMA_TS8 		(1 << 11)
51 #define DMA_DW_BIT		9
52 #define DMA_DW_MASK		(0x03 << DMA_DW_BIT)
53 #define DMA_DW8			(0 << DMA_DW_BIT)
54 #define DMA_DW16		(1 << DMA_DW_BIT)
55 #define DMA_DW32		(2 << DMA_DW_BIT)
56 #define DMA_NC			(1 << 8)
57 #define DMA_IE			(1 << 7)
58 #define DMA_HALT		(1 << 6)
59 #define DMA_GO			(1 << 5)
60 #define DMA_AB			(1 << 4)
61 #define DMA_D1			(1 << 3)
62 #define DMA_BE1 		(1 << 2)
63 #define DMA_D0			(1 << 1)
64 #define DMA_BE0 		(1 << 0)
65 
66 #define DMA_PERIPHERAL_ADDR	0x00000008
67 #define DMA_BUFFER0_START	0x0000000C
68 #define DMA_BUFFER1_START	0x00000014
69 #define DMA_BUFFER0_COUNT	0x00000010
70 #define DMA_BUFFER1_COUNT	0x00000018
71 #define DMA_BAH_BIT	16
72 #define DMA_BAH_MASK	(0x0f << DMA_BAH_BIT)
73 #define DMA_COUNT_BIT	0
74 #define DMA_COUNT_MASK	(0xffff << DMA_COUNT_BIT)
75 
76 /* DMA Device IDs follow */
77 enum {
78 	DMA_ID_UART0_TX = 0,
79 	DMA_ID_UART0_RX,
80 	DMA_ID_GP04,
81 	DMA_ID_GP05,
82 	DMA_ID_AC97C_TX,
83 	DMA_ID_AC97C_RX,
84 	DMA_ID_UART3_TX,
85 	DMA_ID_UART3_RX,
86 	DMA_ID_USBDEV_EP0_RX,
87 	DMA_ID_USBDEV_EP0_TX,
88 	DMA_ID_USBDEV_EP2_TX,
89 	DMA_ID_USBDEV_EP3_TX,
90 	DMA_ID_USBDEV_EP4_RX,
91 	DMA_ID_USBDEV_EP5_RX,
92 	DMA_ID_I2S_TX,
93 	DMA_ID_I2S_RX,
94 	DMA_NUM_DEV
95 };
96 
97 /* DMA Device ID's for 2nd bank (AU1100) follow */
98 enum {
99 	DMA_ID_SD0_TX = 0,
100 	DMA_ID_SD0_RX,
101 	DMA_ID_SD1_TX,
102 	DMA_ID_SD1_RX,
103 	DMA_NUM_DEV_BANK2
104 };
105 
106 struct dma_chan {
107 	int dev_id;		/* this channel is allocated if >= 0, */
108 				/* free otherwise */
109 	unsigned int io;
110 	const char *dev_str;
111 	int irq;
112 	void *irq_dev;
113 	unsigned int fifo_addr;
114 	unsigned int mode;
115 };
116 
117 /* These are in arch/mips/au1000/common/dma.c */
118 extern struct dma_chan au1000_dma_table[];
119 extern int request_au1000_dma(int dev_id,
120 			      const char *dev_str,
121 			      irq_handler_t irqhandler,
122 			      unsigned long irqflags,
123 			      void *irq_dev_id);
124 extern void free_au1000_dma(unsigned int dmanr);
125 extern int au1000_dma_read_proc(char *buf, char **start, off_t fpos,
126 				int length, int *eof, void *data);
127 extern void dump_au1000_dma_channel(unsigned int dmanr);
128 extern spinlock_t au1000_dma_spin_lock;
129 
130 static inline struct dma_chan *get_dma_chan(unsigned int dmanr)
131 {
132 	if (dmanr >= NUM_AU1000_DMA_CHANNELS ||
133 	    au1000_dma_table[dmanr].dev_id < 0)
134 		return NULL;
135 	return &au1000_dma_table[dmanr];
136 }
137 
138 static inline unsigned long claim_dma_lock(void)
139 {
140 	unsigned long flags;
141 
142 	spin_lock_irqsave(&au1000_dma_spin_lock, flags);
143 	return flags;
144 }
145 
146 static inline void release_dma_lock(unsigned long flags)
147 {
148 	spin_unlock_irqrestore(&au1000_dma_spin_lock, flags);
149 }
150 
151 /*
152  * Set the DMA buffer enable bits in the mode register.
153  */
154 static inline void enable_dma_buffer0(unsigned int dmanr)
155 {
156 	struct dma_chan *chan = get_dma_chan(dmanr);
157 
158 	if (!chan)
159 		return;
160 	au_writel(DMA_BE0, chan->io + DMA_MODE_SET);
161 }
162 
163 static inline void enable_dma_buffer1(unsigned int dmanr)
164 {
165 	struct dma_chan *chan = get_dma_chan(dmanr);
166 
167 	if (!chan)
168 		return;
169 	au_writel(DMA_BE1, chan->io + DMA_MODE_SET);
170 }
171 static inline void enable_dma_buffers(unsigned int dmanr)
172 {
173 	struct dma_chan *chan = get_dma_chan(dmanr);
174 
175 	if (!chan)
176 		return;
177 	au_writel(DMA_BE0 | DMA_BE1, chan->io + DMA_MODE_SET);
178 }
179 
180 static inline void start_dma(unsigned int dmanr)
181 {
182 	struct dma_chan *chan = get_dma_chan(dmanr);
183 
184 	if (!chan)
185 		return;
186 	au_writel(DMA_GO, chan->io + DMA_MODE_SET);
187 }
188 
189 #define DMA_HALT_POLL 0x5000
190 
191 static inline void halt_dma(unsigned int dmanr)
192 {
193 	struct dma_chan *chan = get_dma_chan(dmanr);
194 	int i;
195 
196 	if (!chan)
197 		return;
198 	au_writel(DMA_GO, chan->io + DMA_MODE_CLEAR);
199 
200 	/* Poll the halt bit */
201 	for (i = 0; i < DMA_HALT_POLL; i++)
202 		if (au_readl(chan->io + DMA_MODE_READ) & DMA_HALT)
203 			break;
204 	if (i == DMA_HALT_POLL)
205 		printk(KERN_INFO "halt_dma: HALT poll expired!\n");
206 }
207 
208 static inline void disable_dma(unsigned int dmanr)
209 {
210 	struct dma_chan *chan = get_dma_chan(dmanr);
211 
212 	if (!chan)
213 		return;
214 
215 	halt_dma(dmanr);
216 
217 	/* Now we can disable the buffers */
218 	au_writel(~DMA_GO, chan->io + DMA_MODE_CLEAR);
219 }
220 
221 static inline int dma_halted(unsigned int dmanr)
222 {
223 	struct dma_chan *chan = get_dma_chan(dmanr);
224 
225 	if (!chan)
226 		return 1;
227 	return (au_readl(chan->io + DMA_MODE_READ) & DMA_HALT) ? 1 : 0;
228 }
229 
230 /* Initialize a DMA channel. */
231 static inline void init_dma(unsigned int dmanr)
232 {
233 	struct dma_chan *chan = get_dma_chan(dmanr);
234 	u32 mode;
235 
236 	if (!chan)
237 		return;
238 
239 	disable_dma(dmanr);
240 
241 	/* Set device FIFO address */
242 	au_writel(CPHYSADDR(chan->fifo_addr), chan->io + DMA_PERIPHERAL_ADDR);
243 
244 	mode = chan->mode | (chan->dev_id << DMA_DID_BIT);
245 	if (chan->irq)
246 		mode |= DMA_IE;
247 
248 	au_writel(~mode, chan->io + DMA_MODE_CLEAR);
249 	au_writel(mode,  chan->io + DMA_MODE_SET);
250 }
251 
252 /*
253  * Set mode for a specific DMA channel
254  */
255 static inline void set_dma_mode(unsigned int dmanr, unsigned int mode)
256 {
257 	struct dma_chan *chan = get_dma_chan(dmanr);
258 
259 	if (!chan)
260 		return;
261 	/*
262 	 * set_dma_mode is only allowed to change endianess, direction,
263 	 * transfer size, device FIFO width, and coherency settings.
264 	 * Make sure anything else is masked off.
265 	 */
266 	mode &= (DMA_BE | DMA_DR | DMA_TS8 | DMA_DW_MASK | DMA_NC);
267 	chan->mode &= ~(DMA_BE | DMA_DR | DMA_TS8 | DMA_DW_MASK | DMA_NC);
268 	chan->mode |= mode;
269 }
270 
271 static inline unsigned int get_dma_mode(unsigned int dmanr)
272 {
273 	struct dma_chan *chan = get_dma_chan(dmanr);
274 
275 	if (!chan)
276 		return 0;
277 	return chan->mode;
278 }
279 
280 static inline int get_dma_active_buffer(unsigned int dmanr)
281 {
282 	struct dma_chan *chan = get_dma_chan(dmanr);
283 
284 	if (!chan)
285 		return -1;
286 	return (au_readl(chan->io + DMA_MODE_READ) & DMA_AB) ? 1 : 0;
287 }
288 
289 /*
290  * Set the device FIFO address for a specific DMA channel - only
291  * applicable to GPO4 and GPO5. All the other devices have fixed
292  * FIFO addresses.
293  */
294 static inline void set_dma_fifo_addr(unsigned int dmanr, unsigned int a)
295 {
296 	struct dma_chan *chan = get_dma_chan(dmanr);
297 
298 	if (!chan)
299 		return;
300 
301 	if (chan->mode & DMA_DS)	/* second bank of device IDs */
302 		return;
303 
304 	if (chan->dev_id != DMA_ID_GP04 && chan->dev_id != DMA_ID_GP05)
305 		return;
306 
307 	au_writel(CPHYSADDR(a), chan->io + DMA_PERIPHERAL_ADDR);
308 }
309 
310 /*
311  * Clear the DMA buffer done bits in the mode register.
312  */
313 static inline void clear_dma_done0(unsigned int dmanr)
314 {
315 	struct dma_chan *chan = get_dma_chan(dmanr);
316 
317 	if (!chan)
318 		return;
319 	au_writel(DMA_D0, chan->io + DMA_MODE_CLEAR);
320 }
321 
322 static inline void clear_dma_done1(unsigned int dmanr)
323 {
324 	struct dma_chan *chan = get_dma_chan(dmanr);
325 
326 	if (!chan)
327 		return;
328 	au_writel(DMA_D1, chan->io + DMA_MODE_CLEAR);
329 }
330 
331 /*
332  * This does nothing - not applicable to Au1000 DMA.
333  */
334 static inline void set_dma_page(unsigned int dmanr, char pagenr)
335 {
336 }
337 
338 /*
339  * Set Buffer 0 transfer address for specific DMA channel.
340  */
341 static inline void set_dma_addr0(unsigned int dmanr, unsigned int a)
342 {
343 	struct dma_chan *chan = get_dma_chan(dmanr);
344 
345 	if (!chan)
346 		return;
347 	au_writel(a, chan->io + DMA_BUFFER0_START);
348 }
349 
350 /*
351  * Set Buffer 1 transfer address for specific DMA channel.
352  */
353 static inline void set_dma_addr1(unsigned int dmanr, unsigned int a)
354 {
355 	struct dma_chan *chan = get_dma_chan(dmanr);
356 
357 	if (!chan)
358 		return;
359 	au_writel(a, chan->io + DMA_BUFFER1_START);
360 }
361 
362 
363 /*
364  * Set Buffer 0 transfer size (max 64k) for a specific DMA channel.
365  */
366 static inline void set_dma_count0(unsigned int dmanr, unsigned int count)
367 {
368 	struct dma_chan *chan = get_dma_chan(dmanr);
369 
370 	if (!chan)
371 		return;
372 	count &= DMA_COUNT_MASK;
373 	au_writel(count, chan->io + DMA_BUFFER0_COUNT);
374 }
375 
376 /*
377  * Set Buffer 1 transfer size (max 64k) for a specific DMA channel.
378  */
379 static inline void set_dma_count1(unsigned int dmanr, unsigned int count)
380 {
381 	struct dma_chan *chan = get_dma_chan(dmanr);
382 
383 	if (!chan)
384 		return;
385 	count &= DMA_COUNT_MASK;
386 	au_writel(count, chan->io + DMA_BUFFER1_COUNT);
387 }
388 
389 /*
390  * Set both buffer transfer sizes (max 64k) for a specific DMA channel.
391  */
392 static inline void set_dma_count(unsigned int dmanr, unsigned int count)
393 {
394 	struct dma_chan *chan = get_dma_chan(dmanr);
395 
396 	if (!chan)
397 		return;
398 	count &= DMA_COUNT_MASK;
399 	au_writel(count, chan->io + DMA_BUFFER0_COUNT);
400 	au_writel(count, chan->io + DMA_BUFFER1_COUNT);
401 }
402 
403 /*
404  * Returns which buffer has its done bit set in the mode register.
405  * Returns -1 if neither or both done bits set.
406  */
407 static inline unsigned int get_dma_buffer_done(unsigned int dmanr)
408 {
409 	struct dma_chan *chan = get_dma_chan(dmanr);
410 
411 	if (!chan)
412 		return 0;
413 	return au_readl(chan->io + DMA_MODE_READ) & (DMA_D0 | DMA_D1);
414 }
415 
416 
417 /*
418  * Returns the DMA channel's Buffer Done IRQ number.
419  */
420 static inline int get_dma_done_irq(unsigned int dmanr)
421 {
422 	struct dma_chan *chan = get_dma_chan(dmanr);
423 
424 	if (!chan)
425 		return -1;
426 	return chan->irq;
427 }
428 
429 /*
430  * Get DMA residue count. Returns the number of _bytes_ left to transfer.
431  */
432 static inline int get_dma_residue(unsigned int dmanr)
433 {
434 	int curBufCntReg, count;
435 	struct dma_chan *chan = get_dma_chan(dmanr);
436 
437 	if (!chan)
438 		return 0;
439 
440 	curBufCntReg = (au_readl(chan->io + DMA_MODE_READ) & DMA_AB) ?
441 	    DMA_BUFFER1_COUNT : DMA_BUFFER0_COUNT;
442 
443 	count = au_readl(chan->io + curBufCntReg) & DMA_COUNT_MASK;
444 
445 	if ((chan->mode & DMA_DW_MASK) == DMA_DW16)
446 		count <<= 1;
447 	else if ((chan->mode & DMA_DW_MASK) == DMA_DW32)
448 		count <<= 2;
449 
450 	return count;
451 }
452 
453 #endif /* __ASM_AU1000_DMA_H */
454