xref: /linux/arch/mips/alchemy/common/dbdma.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 /*
2  *
3  * BRIEF MODULE DESCRIPTION
4  *      The Descriptor Based DMA channel manager that first appeared
5  *	on the Au1550.  I started with dma.c, but I think all that is
6  *	left is this initial comment :-)
7  *
8  * Copyright 2004 Embedded Edge, LLC
9  *	dan@embeddededge.com
10  *
11  *  This program is free software; you can redistribute  it and/or modify it
12  *  under  the terms of  the GNU General  Public License as published by the
13  *  Free Software Foundation;  either version 2 of the  License, or (at your
14  *  option) any later version.
15  *
16  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
17  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
18  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
19  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
20  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
22  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
23  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
24  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  *  You should have received a copy of the  GNU General Public License along
28  *  with this program; if not, write  to the Free Software Foundation, Inc.,
29  *  675 Mass Ave, Cambridge, MA 02139, USA.
30  *
31  */
32 
33 #include <linux/dma-map-ops.h> /* for dma_default_coherent */
34 #include <linux/init.h>
35 #include <linux/kernel.h>
36 #include <linux/slab.h>
37 #include <linux/spinlock.h>
38 #include <linux/interrupt.h>
39 #include <linux/export.h>
40 #include <linux/syscore_ops.h>
41 #include <asm/mach-au1x00/au1000.h>
42 #include <asm/mach-au1x00/au1xxx_dbdma.h>
43 
44 /*
45  * The Descriptor Based DMA supports up to 16 channels.
46  *
47  * There are 32 devices defined. We keep an internal structure
48  * of devices using these channels, along with additional
49  * information.
50  *
51  * We allocate the descriptors and allow access to them through various
52  * functions.  The drivers allocate the data buffers and assign them
53  * to the descriptors.
54  */
55 static DEFINE_SPINLOCK(au1xxx_dbdma_spin_lock);
56 
57 /* I couldn't find a macro that did this... */
58 #define ALIGN_ADDR(x, a)	((((u32)(x)) + (a-1)) & ~(a-1))
59 
60 static dbdma_global_t *dbdma_gptr =
61 			(dbdma_global_t *)KSEG1ADDR(AU1550_DBDMA_CONF_PHYS_ADDR);
62 static int dbdma_initialized;
63 
64 static dbdev_tab_t *dbdev_tab;
65 
66 static dbdev_tab_t au1550_dbdev_tab[] __initdata = {
67 	/* UARTS */
68 	{ AU1550_DSCR_CMD0_UART0_TX, DEV_FLAGS_OUT, 0, 8, 0x11100004, 0, 0 },
69 	{ AU1550_DSCR_CMD0_UART0_RX, DEV_FLAGS_IN,  0, 8, 0x11100000, 0, 0 },
70 	{ AU1550_DSCR_CMD0_UART3_TX, DEV_FLAGS_OUT, 0, 8, 0x11400004, 0, 0 },
71 	{ AU1550_DSCR_CMD0_UART3_RX, DEV_FLAGS_IN,  0, 8, 0x11400000, 0, 0 },
72 
73 	/* EXT DMA */
74 	{ AU1550_DSCR_CMD0_DMA_REQ0, 0, 0, 0, 0x00000000, 0, 0 },
75 	{ AU1550_DSCR_CMD0_DMA_REQ1, 0, 0, 0, 0x00000000, 0, 0 },
76 	{ AU1550_DSCR_CMD0_DMA_REQ2, 0, 0, 0, 0x00000000, 0, 0 },
77 	{ AU1550_DSCR_CMD0_DMA_REQ3, 0, 0, 0, 0x00000000, 0, 0 },
78 
79 	/* USB DEV */
80 	{ AU1550_DSCR_CMD0_USBDEV_RX0, DEV_FLAGS_IN,  4, 8, 0x10200000, 0, 0 },
81 	{ AU1550_DSCR_CMD0_USBDEV_TX0, DEV_FLAGS_OUT, 4, 8, 0x10200004, 0, 0 },
82 	{ AU1550_DSCR_CMD0_USBDEV_TX1, DEV_FLAGS_OUT, 4, 8, 0x10200008, 0, 0 },
83 	{ AU1550_DSCR_CMD0_USBDEV_TX2, DEV_FLAGS_OUT, 4, 8, 0x1020000c, 0, 0 },
84 	{ AU1550_DSCR_CMD0_USBDEV_RX3, DEV_FLAGS_IN,  4, 8, 0x10200010, 0, 0 },
85 	{ AU1550_DSCR_CMD0_USBDEV_RX4, DEV_FLAGS_IN,  4, 8, 0x10200014, 0, 0 },
86 
87 	/* PSCs */
88 	{ AU1550_DSCR_CMD0_PSC0_TX, DEV_FLAGS_OUT, 0, 0, 0x11a0001c, 0, 0 },
89 	{ AU1550_DSCR_CMD0_PSC0_RX, DEV_FLAGS_IN,  0, 0, 0x11a0001c, 0, 0 },
90 	{ AU1550_DSCR_CMD0_PSC1_TX, DEV_FLAGS_OUT, 0, 0, 0x11b0001c, 0, 0 },
91 	{ AU1550_DSCR_CMD0_PSC1_RX, DEV_FLAGS_IN,  0, 0, 0x11b0001c, 0, 0 },
92 	{ AU1550_DSCR_CMD0_PSC2_TX, DEV_FLAGS_OUT, 0, 0, 0x10a0001c, 0, 0 },
93 	{ AU1550_DSCR_CMD0_PSC2_RX, DEV_FLAGS_IN,  0, 0, 0x10a0001c, 0, 0 },
94 	{ AU1550_DSCR_CMD0_PSC3_TX, DEV_FLAGS_OUT, 0, 0, 0x10b0001c, 0, 0 },
95 	{ AU1550_DSCR_CMD0_PSC3_RX, DEV_FLAGS_IN,  0, 0, 0x10b0001c, 0, 0 },
96 
97 	{ AU1550_DSCR_CMD0_PCI_WRITE,  0, 0, 0, 0x00000000, 0, 0 },  /* PCI */
98 	{ AU1550_DSCR_CMD0_NAND_FLASH, 0, 0, 0, 0x00000000, 0, 0 }, /* NAND */
99 
100 	/* MAC 0 */
101 	{ AU1550_DSCR_CMD0_MAC0_RX, DEV_FLAGS_IN,  0, 0, 0x00000000, 0, 0 },
102 	{ AU1550_DSCR_CMD0_MAC0_TX, DEV_FLAGS_OUT, 0, 0, 0x00000000, 0, 0 },
103 
104 	/* MAC 1 */
105 	{ AU1550_DSCR_CMD0_MAC1_RX, DEV_FLAGS_IN,  0, 0, 0x00000000, 0, 0 },
106 	{ AU1550_DSCR_CMD0_MAC1_TX, DEV_FLAGS_OUT, 0, 0, 0x00000000, 0, 0 },
107 
108 	{ DSCR_CMD0_THROTTLE, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
109 	{ DSCR_CMD0_ALWAYS,   DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
110 };
111 
112 static dbdev_tab_t au1200_dbdev_tab[] __initdata = {
113 	{ AU1200_DSCR_CMD0_UART0_TX, DEV_FLAGS_OUT, 0, 8, 0x11100004, 0, 0 },
114 	{ AU1200_DSCR_CMD0_UART0_RX, DEV_FLAGS_IN,  0, 8, 0x11100000, 0, 0 },
115 	{ AU1200_DSCR_CMD0_UART1_TX, DEV_FLAGS_OUT, 0, 8, 0x11200004, 0, 0 },
116 	{ AU1200_DSCR_CMD0_UART1_RX, DEV_FLAGS_IN,  0, 8, 0x11200000, 0, 0 },
117 
118 	{ AU1200_DSCR_CMD0_DMA_REQ0, 0, 0, 0, 0x00000000, 0, 0 },
119 	{ AU1200_DSCR_CMD0_DMA_REQ1, 0, 0, 0, 0x00000000, 0, 0 },
120 
121 	{ AU1200_DSCR_CMD0_MAE_BE, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
122 	{ AU1200_DSCR_CMD0_MAE_FE, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
123 	{ AU1200_DSCR_CMD0_MAE_BOTH, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
124 	{ AU1200_DSCR_CMD0_LCD, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
125 
126 	{ AU1200_DSCR_CMD0_SDMS_TX0, DEV_FLAGS_OUT, 4, 8, 0x10600000, 0, 0 },
127 	{ AU1200_DSCR_CMD0_SDMS_RX0, DEV_FLAGS_IN,  4, 8, 0x10600004, 0, 0 },
128 	{ AU1200_DSCR_CMD0_SDMS_TX1, DEV_FLAGS_OUT, 4, 8, 0x10680000, 0, 0 },
129 	{ AU1200_DSCR_CMD0_SDMS_RX1, DEV_FLAGS_IN,  4, 8, 0x10680004, 0, 0 },
130 
131 	{ AU1200_DSCR_CMD0_AES_RX, DEV_FLAGS_IN , 4, 32, 0x10300008, 0, 0 },
132 	{ AU1200_DSCR_CMD0_AES_TX, DEV_FLAGS_OUT, 4, 32, 0x10300004, 0, 0 },
133 
134 	{ AU1200_DSCR_CMD0_PSC0_TX,   DEV_FLAGS_OUT, 0, 16, 0x11a0001c, 0, 0 },
135 	{ AU1200_DSCR_CMD0_PSC0_RX,   DEV_FLAGS_IN,  0, 16, 0x11a0001c, 0, 0 },
136 	{ AU1200_DSCR_CMD0_PSC0_SYNC, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
137 	{ AU1200_DSCR_CMD0_PSC1_TX,   DEV_FLAGS_OUT, 0, 16, 0x11b0001c, 0, 0 },
138 	{ AU1200_DSCR_CMD0_PSC1_RX,   DEV_FLAGS_IN,  0, 16, 0x11b0001c, 0, 0 },
139 	{ AU1200_DSCR_CMD0_PSC1_SYNC, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
140 
141 	{ AU1200_DSCR_CMD0_CIM_RXA,  DEV_FLAGS_IN, 0, 32, 0x14004020, 0, 0 },
142 	{ AU1200_DSCR_CMD0_CIM_RXB,  DEV_FLAGS_IN, 0, 32, 0x14004040, 0, 0 },
143 	{ AU1200_DSCR_CMD0_CIM_RXC,  DEV_FLAGS_IN, 0, 32, 0x14004060, 0, 0 },
144 	{ AU1200_DSCR_CMD0_CIM_SYNC, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
145 
146 	{ AU1200_DSCR_CMD0_NAND_FLASH, DEV_FLAGS_IN, 0, 0, 0x00000000, 0, 0 },
147 
148 	{ DSCR_CMD0_THROTTLE, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
149 	{ DSCR_CMD0_ALWAYS,   DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
150 };
151 
152 static dbdev_tab_t au1300_dbdev_tab[] __initdata = {
153 	{ AU1300_DSCR_CMD0_UART0_TX, DEV_FLAGS_OUT, 0, 8,  0x10100004, 0, 0 },
154 	{ AU1300_DSCR_CMD0_UART0_RX, DEV_FLAGS_IN,  0, 8,  0x10100000, 0, 0 },
155 	{ AU1300_DSCR_CMD0_UART1_TX, DEV_FLAGS_OUT, 0, 8,  0x10101004, 0, 0 },
156 	{ AU1300_DSCR_CMD0_UART1_RX, DEV_FLAGS_IN,  0, 8,  0x10101000, 0, 0 },
157 	{ AU1300_DSCR_CMD0_UART2_TX, DEV_FLAGS_OUT, 0, 8,  0x10102004, 0, 0 },
158 	{ AU1300_DSCR_CMD0_UART2_RX, DEV_FLAGS_IN,  0, 8,  0x10102000, 0, 0 },
159 	{ AU1300_DSCR_CMD0_UART3_TX, DEV_FLAGS_OUT, 0, 8,  0x10103004, 0, 0 },
160 	{ AU1300_DSCR_CMD0_UART3_RX, DEV_FLAGS_IN,  0, 8,  0x10103000, 0, 0 },
161 
162 	{ AU1300_DSCR_CMD0_SDMS_TX0, DEV_FLAGS_OUT, 4, 8,  0x10600000, 0, 0 },
163 	{ AU1300_DSCR_CMD0_SDMS_RX0, DEV_FLAGS_IN,  4, 8,  0x10600004, 0, 0 },
164 	{ AU1300_DSCR_CMD0_SDMS_TX1, DEV_FLAGS_OUT, 8, 8,  0x10601000, 0, 0 },
165 	{ AU1300_DSCR_CMD0_SDMS_RX1, DEV_FLAGS_IN,  8, 8,  0x10601004, 0, 0 },
166 
167 	{ AU1300_DSCR_CMD0_AES_RX, DEV_FLAGS_IN ,   4, 32, 0x10300008, 0, 0 },
168 	{ AU1300_DSCR_CMD0_AES_TX, DEV_FLAGS_OUT,   4, 32, 0x10300004, 0, 0 },
169 
170 	{ AU1300_DSCR_CMD0_PSC0_TX, DEV_FLAGS_OUT,  0, 16, 0x10a0001c, 0, 0 },
171 	{ AU1300_DSCR_CMD0_PSC0_RX, DEV_FLAGS_IN,   0, 16, 0x10a0001c, 0, 0 },
172 	{ AU1300_DSCR_CMD0_PSC1_TX, DEV_FLAGS_OUT,  0, 16, 0x10a0101c, 0, 0 },
173 	{ AU1300_DSCR_CMD0_PSC1_RX, DEV_FLAGS_IN,   0, 16, 0x10a0101c, 0, 0 },
174 	{ AU1300_DSCR_CMD0_PSC2_TX, DEV_FLAGS_OUT,  0, 16, 0x10a0201c, 0, 0 },
175 	{ AU1300_DSCR_CMD0_PSC2_RX, DEV_FLAGS_IN,   0, 16, 0x10a0201c, 0, 0 },
176 	{ AU1300_DSCR_CMD0_PSC3_TX, DEV_FLAGS_OUT,  0, 16, 0x10a0301c, 0, 0 },
177 	{ AU1300_DSCR_CMD0_PSC3_RX, DEV_FLAGS_IN,   0, 16, 0x10a0301c, 0, 0 },
178 
179 	{ AU1300_DSCR_CMD0_LCD, DEV_FLAGS_ANYUSE,   0, 0,  0x00000000, 0, 0 },
180 	{ AU1300_DSCR_CMD0_NAND_FLASH, DEV_FLAGS_IN, 0, 0, 0x00000000, 0, 0 },
181 
182 	{ AU1300_DSCR_CMD0_SDMS_TX2, DEV_FLAGS_OUT, 4, 8,  0x10602000, 0, 0 },
183 	{ AU1300_DSCR_CMD0_SDMS_RX2, DEV_FLAGS_IN,  4, 8,  0x10602004, 0, 0 },
184 
185 	{ AU1300_DSCR_CMD0_CIM_SYNC, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
186 
187 	{ AU1300_DSCR_CMD0_UDMA, DEV_FLAGS_ANYUSE,  0, 32, 0x14001810, 0, 0 },
188 
189 	{ AU1300_DSCR_CMD0_DMA_REQ0, 0, 0, 0, 0x00000000, 0, 0 },
190 	{ AU1300_DSCR_CMD0_DMA_REQ1, 0, 0, 0, 0x00000000, 0, 0 },
191 
192 	{ DSCR_CMD0_THROTTLE, DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
193 	{ DSCR_CMD0_ALWAYS,   DEV_FLAGS_ANYUSE, 0, 0, 0x00000000, 0, 0 },
194 };
195 
196 /* 32 predefined plus 32 custom */
197 #define DBDEV_TAB_SIZE		64
198 
199 static chan_tab_t *chan_tab_ptr[NUM_DBDMA_CHANS];
200 
201 static dbdev_tab_t *find_dbdev_id(u32 id)
202 {
203 	int i;
204 	dbdev_tab_t *p;
205 	for (i = 0; i < DBDEV_TAB_SIZE; ++i) {
206 		p = &dbdev_tab[i];
207 		if (p->dev_id == id)
208 			return p;
209 	}
210 	return NULL;
211 }
212 
213 void *au1xxx_ddma_get_nextptr_virt(au1x_ddma_desc_t *dp)
214 {
215 	return phys_to_virt(DSCR_GET_NXTPTR(dp->dscr_nxtptr));
216 }
217 EXPORT_SYMBOL(au1xxx_ddma_get_nextptr_virt);
218 
219 u32 au1xxx_ddma_add_device(dbdev_tab_t *dev)
220 {
221 	u32 ret = 0;
222 	dbdev_tab_t *p;
223 	static u16 new_id = 0x1000;
224 
225 	p = find_dbdev_id(~0);
226 	if (NULL != p) {
227 		memcpy(p, dev, sizeof(dbdev_tab_t));
228 		p->dev_id = DSCR_DEV2CUSTOM_ID(new_id, dev->dev_id);
229 		ret = p->dev_id;
230 		new_id++;
231 #if 0
232 		printk(KERN_DEBUG "add_device: id:%x flags:%x padd:%x\n",
233 				  p->dev_id, p->dev_flags, p->dev_physaddr);
234 #endif
235 	}
236 
237 	return ret;
238 }
239 EXPORT_SYMBOL(au1xxx_ddma_add_device);
240 
241 void au1xxx_ddma_del_device(u32 devid)
242 {
243 	dbdev_tab_t *p = find_dbdev_id(devid);
244 
245 	if (p != NULL) {
246 		memset(p, 0, sizeof(dbdev_tab_t));
247 		p->dev_id = ~0;
248 	}
249 }
250 EXPORT_SYMBOL(au1xxx_ddma_del_device);
251 
252 /* Allocate a channel and return a non-zero descriptor if successful. */
253 u32 au1xxx_dbdma_chan_alloc(u32 srcid, u32 destid,
254        void (*callback)(int, void *), void *callparam)
255 {
256 	unsigned long	flags;
257 	u32		used, chan;
258 	u32		dcp;
259 	int		i;
260 	dbdev_tab_t	*stp, *dtp;
261 	chan_tab_t	*ctp;
262 	au1x_dma_chan_t *cp;
263 
264 	/*
265 	 * We do the initialization on the first channel allocation.
266 	 * We have to wait because of the interrupt handler initialization
267 	 * which can't be done successfully during board set up.
268 	 */
269 	if (!dbdma_initialized)
270 		return 0;
271 
272 	stp = find_dbdev_id(srcid);
273 	if (stp == NULL)
274 		return 0;
275 	dtp = find_dbdev_id(destid);
276 	if (dtp == NULL)
277 		return 0;
278 
279 	used = 0;
280 
281 	/* Check to see if we can get both channels. */
282 	spin_lock_irqsave(&au1xxx_dbdma_spin_lock, flags);
283 	if (!(stp->dev_flags & DEV_FLAGS_INUSE) ||
284 	     (stp->dev_flags & DEV_FLAGS_ANYUSE)) {
285 		/* Got source */
286 		stp->dev_flags |= DEV_FLAGS_INUSE;
287 		if (!(dtp->dev_flags & DEV_FLAGS_INUSE) ||
288 		     (dtp->dev_flags & DEV_FLAGS_ANYUSE)) {
289 			/* Got destination */
290 			dtp->dev_flags |= DEV_FLAGS_INUSE;
291 		} else {
292 			/* Can't get dest.  Release src. */
293 			stp->dev_flags &= ~DEV_FLAGS_INUSE;
294 			used++;
295 		}
296 	} else
297 		used++;
298 	spin_unlock_irqrestore(&au1xxx_dbdma_spin_lock, flags);
299 
300 	if (used)
301 		return 0;
302 
303 	/* Let's see if we can allocate a channel for it. */
304 	ctp = NULL;
305 	chan = 0;
306 	spin_lock_irqsave(&au1xxx_dbdma_spin_lock, flags);
307 	for (i = 0; i < NUM_DBDMA_CHANS; i++)
308 		if (chan_tab_ptr[i] == NULL) {
309 			/*
310 			 * If kmalloc fails, it is caught below same
311 			 * as a channel not available.
312 			 */
313 			ctp = kmalloc(sizeof(chan_tab_t), GFP_ATOMIC);
314 			chan_tab_ptr[i] = ctp;
315 			break;
316 		}
317 	spin_unlock_irqrestore(&au1xxx_dbdma_spin_lock, flags);
318 
319 	if (ctp != NULL) {
320 		memset(ctp, 0, sizeof(chan_tab_t));
321 		ctp->chan_index = chan = i;
322 		dcp = KSEG1ADDR(AU1550_DBDMA_PHYS_ADDR);
323 		dcp += (0x0100 * chan);
324 		ctp->chan_ptr = (au1x_dma_chan_t *)dcp;
325 		cp = (au1x_dma_chan_t *)dcp;
326 		ctp->chan_src = stp;
327 		ctp->chan_dest = dtp;
328 		ctp->chan_callback = callback;
329 		ctp->chan_callparam = callparam;
330 
331 		/* Initialize channel configuration. */
332 		i = 0;
333 		if (stp->dev_intlevel)
334 			i |= DDMA_CFG_SED;
335 		if (stp->dev_intpolarity)
336 			i |= DDMA_CFG_SP;
337 		if (dtp->dev_intlevel)
338 			i |= DDMA_CFG_DED;
339 		if (dtp->dev_intpolarity)
340 			i |= DDMA_CFG_DP;
341 		if ((stp->dev_flags & DEV_FLAGS_SYNC) ||
342 			(dtp->dev_flags & DEV_FLAGS_SYNC))
343 				i |= DDMA_CFG_SYNC;
344 		cp->ddma_cfg = i;
345 		wmb(); /* drain writebuffer */
346 
347 		/*
348 		 * Return a non-zero value that can be used to find the channel
349 		 * information in subsequent operations.
350 		 */
351 		return (u32)(&chan_tab_ptr[chan]);
352 	}
353 
354 	/* Release devices */
355 	stp->dev_flags &= ~DEV_FLAGS_INUSE;
356 	dtp->dev_flags &= ~DEV_FLAGS_INUSE;
357 
358 	return 0;
359 }
360 EXPORT_SYMBOL(au1xxx_dbdma_chan_alloc);
361 
362 /*
363  * Set the device width if source or destination is a FIFO.
364  * Should be 8, 16, or 32 bits.
365  */
366 u32 au1xxx_dbdma_set_devwidth(u32 chanid, int bits)
367 {
368 	u32		rv;
369 	chan_tab_t	*ctp;
370 	dbdev_tab_t	*stp, *dtp;
371 
372 	ctp = *((chan_tab_t **)chanid);
373 	stp = ctp->chan_src;
374 	dtp = ctp->chan_dest;
375 	rv = 0;
376 
377 	if (stp->dev_flags & DEV_FLAGS_IN) {	/* Source in fifo */
378 		rv = stp->dev_devwidth;
379 		stp->dev_devwidth = bits;
380 	}
381 	if (dtp->dev_flags & DEV_FLAGS_OUT) {	/* Destination out fifo */
382 		rv = dtp->dev_devwidth;
383 		dtp->dev_devwidth = bits;
384 	}
385 
386 	return rv;
387 }
388 EXPORT_SYMBOL(au1xxx_dbdma_set_devwidth);
389 
390 /* Allocate a descriptor ring, initializing as much as possible. */
391 u32 au1xxx_dbdma_ring_alloc(u32 chanid, int entries)
392 {
393 	int			i;
394 	u32			desc_base, srcid, destid;
395 	u32			cmd0, cmd1, src1, dest1;
396 	u32			src0, dest0;
397 	chan_tab_t		*ctp;
398 	dbdev_tab_t		*stp, *dtp;
399 	au1x_ddma_desc_t	*dp;
400 
401 	/*
402 	 * I guess we could check this to be within the
403 	 * range of the table......
404 	 */
405 	ctp = *((chan_tab_t **)chanid);
406 	stp = ctp->chan_src;
407 	dtp = ctp->chan_dest;
408 
409 	/*
410 	 * The descriptors must be 32-byte aligned.  There is a
411 	 * possibility the allocation will give us such an address,
412 	 * and if we try that first we are likely to not waste larger
413 	 * slabs of memory.
414 	 */
415 	desc_base = (u32)kmalloc_array(entries, sizeof(au1x_ddma_desc_t),
416 				       GFP_KERNEL|GFP_DMA);
417 	if (desc_base == 0)
418 		return 0;
419 
420 	if (desc_base & 0x1f) {
421 		/*
422 		 * Lost....do it again, allocate extra, and round
423 		 * the address base.
424 		 */
425 		kfree((const void *)desc_base);
426 		i = entries * sizeof(au1x_ddma_desc_t);
427 		i += (sizeof(au1x_ddma_desc_t) - 1);
428 		desc_base = (u32)kmalloc(i, GFP_KERNEL|GFP_DMA);
429 		if (desc_base == 0)
430 			return 0;
431 
432 		ctp->cdb_membase = desc_base;
433 		desc_base = ALIGN_ADDR(desc_base, sizeof(au1x_ddma_desc_t));
434 	} else
435 		ctp->cdb_membase = desc_base;
436 
437 	dp = (au1x_ddma_desc_t *)desc_base;
438 
439 	/* Keep track of the base descriptor. */
440 	ctp->chan_desc_base = dp;
441 
442 	/* Initialize the rings with as much information as we know. */
443 	srcid = stp->dev_id;
444 	destid = dtp->dev_id;
445 
446 	cmd0 = cmd1 = src1 = dest1 = 0;
447 	src0 = dest0 = 0;
448 
449 	cmd0 |= DSCR_CMD0_SID(srcid);
450 	cmd0 |= DSCR_CMD0_DID(destid);
451 	cmd0 |= DSCR_CMD0_IE | DSCR_CMD0_CV;
452 	cmd0 |= DSCR_CMD0_ST(DSCR_CMD0_ST_NOCHANGE);
453 
454 	/* Is it mem to mem transfer? */
455 	if (((DSCR_CUSTOM2DEV_ID(srcid) == DSCR_CMD0_THROTTLE) ||
456 	     (DSCR_CUSTOM2DEV_ID(srcid) == DSCR_CMD0_ALWAYS)) &&
457 	    ((DSCR_CUSTOM2DEV_ID(destid) == DSCR_CMD0_THROTTLE) ||
458 	     (DSCR_CUSTOM2DEV_ID(destid) == DSCR_CMD0_ALWAYS)))
459 		cmd0 |= DSCR_CMD0_MEM;
460 
461 	switch (stp->dev_devwidth) {
462 	case 8:
463 		cmd0 |= DSCR_CMD0_SW(DSCR_CMD0_BYTE);
464 		break;
465 	case 16:
466 		cmd0 |= DSCR_CMD0_SW(DSCR_CMD0_HALFWORD);
467 		break;
468 	case 32:
469 	default:
470 		cmd0 |= DSCR_CMD0_SW(DSCR_CMD0_WORD);
471 		break;
472 	}
473 
474 	switch (dtp->dev_devwidth) {
475 	case 8:
476 		cmd0 |= DSCR_CMD0_DW(DSCR_CMD0_BYTE);
477 		break;
478 	case 16:
479 		cmd0 |= DSCR_CMD0_DW(DSCR_CMD0_HALFWORD);
480 		break;
481 	case 32:
482 	default:
483 		cmd0 |= DSCR_CMD0_DW(DSCR_CMD0_WORD);
484 		break;
485 	}
486 
487 	/*
488 	 * If the device is marked as an in/out FIFO, ensure it is
489 	 * set non-coherent.
490 	 */
491 	if (stp->dev_flags & DEV_FLAGS_IN)
492 		cmd0 |= DSCR_CMD0_SN;		/* Source in FIFO */
493 	if (dtp->dev_flags & DEV_FLAGS_OUT)
494 		cmd0 |= DSCR_CMD0_DN;		/* Destination out FIFO */
495 
496 	/*
497 	 * Set up source1.  For now, assume no stride and increment.
498 	 * A channel attribute update can change this later.
499 	 */
500 	switch (stp->dev_tsize) {
501 	case 1:
502 		src1 |= DSCR_SRC1_STS(DSCR_xTS_SIZE1);
503 		break;
504 	case 2:
505 		src1 |= DSCR_SRC1_STS(DSCR_xTS_SIZE2);
506 		break;
507 	case 4:
508 		src1 |= DSCR_SRC1_STS(DSCR_xTS_SIZE4);
509 		break;
510 	case 8:
511 	default:
512 		src1 |= DSCR_SRC1_STS(DSCR_xTS_SIZE8);
513 		break;
514 	}
515 
516 	/* If source input is FIFO, set static address. */
517 	if (stp->dev_flags & DEV_FLAGS_IN) {
518 		if (stp->dev_flags & DEV_FLAGS_BURSTABLE)
519 			src1 |= DSCR_SRC1_SAM(DSCR_xAM_BURST);
520 		else
521 			src1 |= DSCR_SRC1_SAM(DSCR_xAM_STATIC);
522 	}
523 
524 	if (stp->dev_physaddr)
525 		src0 = stp->dev_physaddr;
526 
527 	/*
528 	 * Set up dest1.  For now, assume no stride and increment.
529 	 * A channel attribute update can change this later.
530 	 */
531 	switch (dtp->dev_tsize) {
532 	case 1:
533 		dest1 |= DSCR_DEST1_DTS(DSCR_xTS_SIZE1);
534 		break;
535 	case 2:
536 		dest1 |= DSCR_DEST1_DTS(DSCR_xTS_SIZE2);
537 		break;
538 	case 4:
539 		dest1 |= DSCR_DEST1_DTS(DSCR_xTS_SIZE4);
540 		break;
541 	case 8:
542 	default:
543 		dest1 |= DSCR_DEST1_DTS(DSCR_xTS_SIZE8);
544 		break;
545 	}
546 
547 	/* If destination output is FIFO, set static address. */
548 	if (dtp->dev_flags & DEV_FLAGS_OUT) {
549 		if (dtp->dev_flags & DEV_FLAGS_BURSTABLE)
550 			dest1 |= DSCR_DEST1_DAM(DSCR_xAM_BURST);
551 		else
552 			dest1 |= DSCR_DEST1_DAM(DSCR_xAM_STATIC);
553 	}
554 
555 	if (dtp->dev_physaddr)
556 		dest0 = dtp->dev_physaddr;
557 
558 #if 0
559 		printk(KERN_DEBUG "did:%x sid:%x cmd0:%x cmd1:%x source0:%x "
560 				  "source1:%x dest0:%x dest1:%x\n",
561 				  dtp->dev_id, stp->dev_id, cmd0, cmd1, src0,
562 				  src1, dest0, dest1);
563 #endif
564 	for (i = 0; i < entries; i++) {
565 		dp->dscr_cmd0 = cmd0;
566 		dp->dscr_cmd1 = cmd1;
567 		dp->dscr_source0 = src0;
568 		dp->dscr_source1 = src1;
569 		dp->dscr_dest0 = dest0;
570 		dp->dscr_dest1 = dest1;
571 		dp->dscr_stat = 0;
572 		dp->sw_context = 0;
573 		dp->sw_status = 0;
574 		dp->dscr_nxtptr = DSCR_NXTPTR(virt_to_phys(dp + 1));
575 		dp++;
576 	}
577 
578 	/* Make last descriptor point to the first. */
579 	dp--;
580 	dp->dscr_nxtptr = DSCR_NXTPTR(virt_to_phys(ctp->chan_desc_base));
581 	ctp->get_ptr = ctp->put_ptr = ctp->cur_ptr = ctp->chan_desc_base;
582 
583 	return (u32)ctp->chan_desc_base;
584 }
585 EXPORT_SYMBOL(au1xxx_dbdma_ring_alloc);
586 
587 /*
588  * Put a source buffer into the DMA ring.
589  * This updates the source pointer and byte count.  Normally used
590  * for memory to fifo transfers.
591  */
592 u32 au1xxx_dbdma_put_source(u32 chanid, dma_addr_t buf, int nbytes, u32 flags)
593 {
594 	chan_tab_t		*ctp;
595 	au1x_ddma_desc_t	*dp;
596 
597 	/*
598 	 * I guess we could check this to be within the
599 	 * range of the table......
600 	 */
601 	ctp = *(chan_tab_t **)chanid;
602 
603 	/*
604 	 * We should have multiple callers for a particular channel,
605 	 * an interrupt doesn't affect this pointer nor the descriptor,
606 	 * so no locking should be needed.
607 	 */
608 	dp = ctp->put_ptr;
609 
610 	/*
611 	 * If the descriptor is valid, we are way ahead of the DMA
612 	 * engine, so just return an error condition.
613 	 */
614 	if (dp->dscr_cmd0 & DSCR_CMD0_V)
615 		return 0;
616 
617 	/* Load up buffer address and byte count. */
618 	dp->dscr_source0 = buf & ~0UL;
619 	dp->dscr_cmd1 = nbytes;
620 	/* Check flags */
621 	if (flags & DDMA_FLAGS_IE)
622 		dp->dscr_cmd0 |= DSCR_CMD0_IE;
623 	if (flags & DDMA_FLAGS_NOIE)
624 		dp->dscr_cmd0 &= ~DSCR_CMD0_IE;
625 
626 	/*
627 	 * There is an erratum on certain Au1200/Au1550 revisions that could
628 	 * result in "stale" data being DMA'ed. It has to do with the snoop
629 	 * logic on the cache eviction buffer.  dma_default_coherent is set
630 	 * to false on these parts.
631 	 */
632 	if (!dma_default_coherent)
633 		dma_cache_wback_inv(KSEG0ADDR(buf), nbytes);
634 	dp->dscr_cmd0 |= DSCR_CMD0_V;	/* Let it rip */
635 	wmb(); /* drain writebuffer */
636 	dma_cache_wback_inv((unsigned long)dp, sizeof(*dp));
637 	ctp->chan_ptr->ddma_dbell = 0;
638 	wmb(); /* force doorbell write out to dma engine */
639 
640 	/* Get next descriptor pointer. */
641 	ctp->put_ptr = phys_to_virt(DSCR_GET_NXTPTR(dp->dscr_nxtptr));
642 
643 	/* Return something non-zero. */
644 	return nbytes;
645 }
646 EXPORT_SYMBOL(au1xxx_dbdma_put_source);
647 
648 /* Put a destination buffer into the DMA ring.
649  * This updates the destination pointer and byte count.  Normally used
650  * to place an empty buffer into the ring for fifo to memory transfers.
651  */
652 u32 au1xxx_dbdma_put_dest(u32 chanid, dma_addr_t buf, int nbytes, u32 flags)
653 {
654 	chan_tab_t		*ctp;
655 	au1x_ddma_desc_t	*dp;
656 
657 	/* I guess we could check this to be within the
658 	 * range of the table......
659 	 */
660 	ctp = *((chan_tab_t **)chanid);
661 
662 	/* We should have multiple callers for a particular channel,
663 	 * an interrupt doesn't affect this pointer nor the descriptor,
664 	 * so no locking should be needed.
665 	 */
666 	dp = ctp->put_ptr;
667 
668 	/* If the descriptor is valid, we are way ahead of the DMA
669 	 * engine, so just return an error condition.
670 	 */
671 	if (dp->dscr_cmd0 & DSCR_CMD0_V)
672 		return 0;
673 
674 	/* Load up buffer address and byte count */
675 
676 	/* Check flags  */
677 	if (flags & DDMA_FLAGS_IE)
678 		dp->dscr_cmd0 |= DSCR_CMD0_IE;
679 	if (flags & DDMA_FLAGS_NOIE)
680 		dp->dscr_cmd0 &= ~DSCR_CMD0_IE;
681 
682 	dp->dscr_dest0 = buf & ~0UL;
683 	dp->dscr_cmd1 = nbytes;
684 #if 0
685 	printk(KERN_DEBUG "cmd0:%x cmd1:%x source0:%x source1:%x dest0:%x dest1:%x\n",
686 			  dp->dscr_cmd0, dp->dscr_cmd1, dp->dscr_source0,
687 			  dp->dscr_source1, dp->dscr_dest0, dp->dscr_dest1);
688 #endif
689 	/*
690 	 * There is an erratum on certain Au1200/Au1550 revisions that could
691 	 * result in "stale" data being DMA'ed. It has to do with the snoop
692 	 * logic on the cache eviction buffer.  dma_default_coherent is set
693 	 * to false on these parts.
694 	 */
695 	if (!dma_default_coherent)
696 		dma_cache_inv(KSEG0ADDR(buf), nbytes);
697 	dp->dscr_cmd0 |= DSCR_CMD0_V;	/* Let it rip */
698 	wmb(); /* drain writebuffer */
699 	dma_cache_wback_inv((unsigned long)dp, sizeof(*dp));
700 	ctp->chan_ptr->ddma_dbell = 0;
701 	wmb(); /* force doorbell write out to dma engine */
702 
703 	/* Get next descriptor pointer. */
704 	ctp->put_ptr = phys_to_virt(DSCR_GET_NXTPTR(dp->dscr_nxtptr));
705 
706 	/* Return something non-zero. */
707 	return nbytes;
708 }
709 EXPORT_SYMBOL(au1xxx_dbdma_put_dest);
710 
711 /*
712  * Get a destination buffer into the DMA ring.
713  * Normally used to get a full buffer from the ring during fifo
714  * to memory transfers.  This does not set the valid bit, you will
715  * have to put another destination buffer to keep the DMA going.
716  */
717 u32 au1xxx_dbdma_get_dest(u32 chanid, void **buf, int *nbytes)
718 {
719 	chan_tab_t		*ctp;
720 	au1x_ddma_desc_t	*dp;
721 	u32			rv;
722 
723 	/*
724 	 * I guess we could check this to be within the
725 	 * range of the table......
726 	 */
727 	ctp = *((chan_tab_t **)chanid);
728 
729 	/*
730 	 * We should have multiple callers for a particular channel,
731 	 * an interrupt doesn't affect this pointer nor the descriptor,
732 	 * so no locking should be needed.
733 	 */
734 	dp = ctp->get_ptr;
735 
736 	/*
737 	 * If the descriptor is valid, we are way ahead of the DMA
738 	 * engine, so just return an error condition.
739 	 */
740 	if (dp->dscr_cmd0 & DSCR_CMD0_V)
741 		return 0;
742 
743 	/* Return buffer address and byte count. */
744 	*buf = (void *)(phys_to_virt(dp->dscr_dest0));
745 	*nbytes = dp->dscr_cmd1;
746 	rv = dp->dscr_stat;
747 
748 	/* Get next descriptor pointer. */
749 	ctp->get_ptr = phys_to_virt(DSCR_GET_NXTPTR(dp->dscr_nxtptr));
750 
751 	/* Return something non-zero. */
752 	return rv;
753 }
754 EXPORT_SYMBOL_GPL(au1xxx_dbdma_get_dest);
755 
756 void au1xxx_dbdma_stop(u32 chanid)
757 {
758 	chan_tab_t	*ctp;
759 	au1x_dma_chan_t *cp;
760 	int halt_timeout = 0;
761 
762 	ctp = *((chan_tab_t **)chanid);
763 
764 	cp = ctp->chan_ptr;
765 	cp->ddma_cfg &= ~DDMA_CFG_EN;	/* Disable channel */
766 	wmb(); /* drain writebuffer */
767 	while (!(cp->ddma_stat & DDMA_STAT_H)) {
768 		udelay(1);
769 		halt_timeout++;
770 		if (halt_timeout > 100) {
771 			printk(KERN_WARNING "warning: DMA channel won't halt\n");
772 			break;
773 		}
774 	}
775 	/* clear current desc valid and doorbell */
776 	cp->ddma_stat |= (DDMA_STAT_DB | DDMA_STAT_V);
777 	wmb(); /* drain writebuffer */
778 }
779 EXPORT_SYMBOL(au1xxx_dbdma_stop);
780 
781 /*
782  * Start using the current descriptor pointer.  If the DBDMA encounters
783  * a non-valid descriptor, it will stop.  In this case, we can just
784  * continue by adding a buffer to the list and starting again.
785  */
786 void au1xxx_dbdma_start(u32 chanid)
787 {
788 	chan_tab_t	*ctp;
789 	au1x_dma_chan_t *cp;
790 
791 	ctp = *((chan_tab_t **)chanid);
792 	cp = ctp->chan_ptr;
793 	cp->ddma_desptr = virt_to_phys(ctp->cur_ptr);
794 	cp->ddma_cfg |= DDMA_CFG_EN;	/* Enable channel */
795 	wmb(); /* drain writebuffer */
796 	cp->ddma_dbell = 0;
797 	wmb(); /* drain writebuffer */
798 }
799 EXPORT_SYMBOL(au1xxx_dbdma_start);
800 
801 void au1xxx_dbdma_reset(u32 chanid)
802 {
803 	chan_tab_t		*ctp;
804 	au1x_ddma_desc_t	*dp;
805 
806 	au1xxx_dbdma_stop(chanid);
807 
808 	ctp = *((chan_tab_t **)chanid);
809 	ctp->get_ptr = ctp->put_ptr = ctp->cur_ptr = ctp->chan_desc_base;
810 
811 	/* Run through the descriptors and reset the valid indicator. */
812 	dp = ctp->chan_desc_base;
813 
814 	do {
815 		dp->dscr_cmd0 &= ~DSCR_CMD0_V;
816 		/*
817 		 * Reset our software status -- this is used to determine
818 		 * if a descriptor is in use by upper level software. Since
819 		 * posting can reset 'V' bit.
820 		 */
821 		dp->sw_status = 0;
822 		dp = phys_to_virt(DSCR_GET_NXTPTR(dp->dscr_nxtptr));
823 	} while (dp != ctp->chan_desc_base);
824 }
825 EXPORT_SYMBOL(au1xxx_dbdma_reset);
826 
827 u32 au1xxx_get_dma_residue(u32 chanid)
828 {
829 	chan_tab_t	*ctp;
830 	au1x_dma_chan_t *cp;
831 	u32		rv;
832 
833 	ctp = *((chan_tab_t **)chanid);
834 	cp = ctp->chan_ptr;
835 
836 	/* This is only valid if the channel is stopped. */
837 	rv = cp->ddma_bytecnt;
838 	wmb(); /* drain writebuffer */
839 
840 	return rv;
841 }
842 EXPORT_SYMBOL_GPL(au1xxx_get_dma_residue);
843 
844 void au1xxx_dbdma_chan_free(u32 chanid)
845 {
846 	chan_tab_t	*ctp;
847 	dbdev_tab_t	*stp, *dtp;
848 
849 	ctp = *((chan_tab_t **)chanid);
850 	stp = ctp->chan_src;
851 	dtp = ctp->chan_dest;
852 
853 	au1xxx_dbdma_stop(chanid);
854 
855 	kfree((void *)ctp->cdb_membase);
856 
857 	stp->dev_flags &= ~DEV_FLAGS_INUSE;
858 	dtp->dev_flags &= ~DEV_FLAGS_INUSE;
859 	chan_tab_ptr[ctp->chan_index] = NULL;
860 
861 	kfree(ctp);
862 }
863 EXPORT_SYMBOL(au1xxx_dbdma_chan_free);
864 
865 static irqreturn_t dbdma_interrupt(int irq, void *dev_id)
866 {
867 	u32 intstat;
868 	u32 chan_index;
869 	chan_tab_t		*ctp;
870 	au1x_ddma_desc_t	*dp;
871 	au1x_dma_chan_t *cp;
872 
873 	intstat = dbdma_gptr->ddma_intstat;
874 	wmb(); /* drain writebuffer */
875 	chan_index = __ffs(intstat);
876 
877 	ctp = chan_tab_ptr[chan_index];
878 	cp = ctp->chan_ptr;
879 	dp = ctp->cur_ptr;
880 
881 	/* Reset interrupt. */
882 	cp->ddma_irq = 0;
883 	wmb(); /* drain writebuffer */
884 
885 	if (ctp->chan_callback)
886 		ctp->chan_callback(irq, ctp->chan_callparam);
887 
888 	ctp->cur_ptr = phys_to_virt(DSCR_GET_NXTPTR(dp->dscr_nxtptr));
889 	return IRQ_RETVAL(1);
890 }
891 
892 void au1xxx_dbdma_dump(u32 chanid)
893 {
894 	chan_tab_t	 *ctp;
895 	au1x_ddma_desc_t *dp;
896 	dbdev_tab_t	 *stp, *dtp;
897 	au1x_dma_chan_t	 *cp;
898 	u32 i		 = 0;
899 
900 	ctp = *((chan_tab_t **)chanid);
901 	stp = ctp->chan_src;
902 	dtp = ctp->chan_dest;
903 	cp = ctp->chan_ptr;
904 
905 	printk(KERN_DEBUG "Chan %x, stp %x (dev %d)  dtp %x (dev %d)\n",
906 			  (u32)ctp, (u32)stp, stp - dbdev_tab, (u32)dtp,
907 			  dtp - dbdev_tab);
908 	printk(KERN_DEBUG "desc base %x, get %x, put %x, cur %x\n",
909 			  (u32)(ctp->chan_desc_base), (u32)(ctp->get_ptr),
910 			  (u32)(ctp->put_ptr), (u32)(ctp->cur_ptr));
911 
912 	printk(KERN_DEBUG "dbdma chan %x\n", (u32)cp);
913 	printk(KERN_DEBUG "cfg %08x, desptr %08x, statptr %08x\n",
914 			  cp->ddma_cfg, cp->ddma_desptr, cp->ddma_statptr);
915 	printk(KERN_DEBUG "dbell %08x, irq %08x, stat %08x, bytecnt %08x\n",
916 			  cp->ddma_dbell, cp->ddma_irq, cp->ddma_stat,
917 			  cp->ddma_bytecnt);
918 
919 	/* Run through the descriptors */
920 	dp = ctp->chan_desc_base;
921 
922 	do {
923 		printk(KERN_DEBUG "Dp[%d]= %08x, cmd0 %08x, cmd1 %08x\n",
924 				  i++, (u32)dp, dp->dscr_cmd0, dp->dscr_cmd1);
925 		printk(KERN_DEBUG "src0 %08x, src1 %08x, dest0 %08x, dest1 %08x\n",
926 				  dp->dscr_source0, dp->dscr_source1,
927 				  dp->dscr_dest0, dp->dscr_dest1);
928 		printk(KERN_DEBUG "stat %08x, nxtptr %08x\n",
929 				  dp->dscr_stat, dp->dscr_nxtptr);
930 		dp = phys_to_virt(DSCR_GET_NXTPTR(dp->dscr_nxtptr));
931 	} while (dp != ctp->chan_desc_base);
932 }
933 
934 /* Put a descriptor into the DMA ring.
935  * This updates the source/destination pointers and byte count.
936  */
937 u32 au1xxx_dbdma_put_dscr(u32 chanid, au1x_ddma_desc_t *dscr)
938 {
939 	chan_tab_t *ctp;
940 	au1x_ddma_desc_t *dp;
941 	u32 nbytes = 0;
942 
943 	/*
944 	 * I guess we could check this to be within the
945 	 * range of the table......
946 	 */
947 	ctp = *((chan_tab_t **)chanid);
948 
949 	/*
950 	 * We should have multiple callers for a particular channel,
951 	 * an interrupt doesn't affect this pointer nor the descriptor,
952 	 * so no locking should be needed.
953 	 */
954 	dp = ctp->put_ptr;
955 
956 	/*
957 	 * If the descriptor is valid, we are way ahead of the DMA
958 	 * engine, so just return an error condition.
959 	 */
960 	if (dp->dscr_cmd0 & DSCR_CMD0_V)
961 		return 0;
962 
963 	/* Load up buffer addresses and byte count. */
964 	dp->dscr_dest0 = dscr->dscr_dest0;
965 	dp->dscr_source0 = dscr->dscr_source0;
966 	dp->dscr_dest1 = dscr->dscr_dest1;
967 	dp->dscr_source1 = dscr->dscr_source1;
968 	dp->dscr_cmd1 = dscr->dscr_cmd1;
969 	nbytes = dscr->dscr_cmd1;
970 	/* Allow the caller to specify if an interrupt is generated */
971 	dp->dscr_cmd0 &= ~DSCR_CMD0_IE;
972 	dp->dscr_cmd0 |= dscr->dscr_cmd0 | DSCR_CMD0_V;
973 	ctp->chan_ptr->ddma_dbell = 0;
974 
975 	/* Get next descriptor pointer. */
976 	ctp->put_ptr = phys_to_virt(DSCR_GET_NXTPTR(dp->dscr_nxtptr));
977 
978 	/* Return something non-zero. */
979 	return nbytes;
980 }
981 
982 
983 static unsigned long alchemy_dbdma_pm_data[NUM_DBDMA_CHANS + 1][6];
984 
985 static int alchemy_dbdma_suspend(void)
986 {
987 	int i;
988 	void __iomem *addr;
989 
990 	addr = (void __iomem *)KSEG1ADDR(AU1550_DBDMA_CONF_PHYS_ADDR);
991 	alchemy_dbdma_pm_data[0][0] = __raw_readl(addr + 0x00);
992 	alchemy_dbdma_pm_data[0][1] = __raw_readl(addr + 0x04);
993 	alchemy_dbdma_pm_data[0][2] = __raw_readl(addr + 0x08);
994 	alchemy_dbdma_pm_data[0][3] = __raw_readl(addr + 0x0c);
995 
996 	/* save channel configurations */
997 	addr = (void __iomem *)KSEG1ADDR(AU1550_DBDMA_PHYS_ADDR);
998 	for (i = 1; i <= NUM_DBDMA_CHANS; i++) {
999 		alchemy_dbdma_pm_data[i][0] = __raw_readl(addr + 0x00);
1000 		alchemy_dbdma_pm_data[i][1] = __raw_readl(addr + 0x04);
1001 		alchemy_dbdma_pm_data[i][2] = __raw_readl(addr + 0x08);
1002 		alchemy_dbdma_pm_data[i][3] = __raw_readl(addr + 0x0c);
1003 		alchemy_dbdma_pm_data[i][4] = __raw_readl(addr + 0x10);
1004 		alchemy_dbdma_pm_data[i][5] = __raw_readl(addr + 0x14);
1005 
1006 		/* halt channel */
1007 		__raw_writel(alchemy_dbdma_pm_data[i][0] & ~1, addr + 0x00);
1008 		wmb();
1009 		while (!(__raw_readl(addr + 0x14) & 1))
1010 			wmb();
1011 
1012 		addr += 0x100;	/* next channel base */
1013 	}
1014 	/* disable channel interrupts */
1015 	addr = (void __iomem *)KSEG1ADDR(AU1550_DBDMA_CONF_PHYS_ADDR);
1016 	__raw_writel(0, addr + 0x0c);
1017 	wmb();
1018 
1019 	return 0;
1020 }
1021 
1022 static void alchemy_dbdma_resume(void)
1023 {
1024 	int i;
1025 	void __iomem *addr;
1026 
1027 	addr = (void __iomem *)KSEG1ADDR(AU1550_DBDMA_CONF_PHYS_ADDR);
1028 	__raw_writel(alchemy_dbdma_pm_data[0][0], addr + 0x00);
1029 	__raw_writel(alchemy_dbdma_pm_data[0][1], addr + 0x04);
1030 	__raw_writel(alchemy_dbdma_pm_data[0][2], addr + 0x08);
1031 	__raw_writel(alchemy_dbdma_pm_data[0][3], addr + 0x0c);
1032 
1033 	/* restore channel configurations */
1034 	addr = (void __iomem *)KSEG1ADDR(AU1550_DBDMA_PHYS_ADDR);
1035 	for (i = 1; i <= NUM_DBDMA_CHANS; i++) {
1036 		__raw_writel(alchemy_dbdma_pm_data[i][0], addr + 0x00);
1037 		__raw_writel(alchemy_dbdma_pm_data[i][1], addr + 0x04);
1038 		__raw_writel(alchemy_dbdma_pm_data[i][2], addr + 0x08);
1039 		__raw_writel(alchemy_dbdma_pm_data[i][3], addr + 0x0c);
1040 		__raw_writel(alchemy_dbdma_pm_data[i][4], addr + 0x10);
1041 		__raw_writel(alchemy_dbdma_pm_data[i][5], addr + 0x14);
1042 		wmb();
1043 		addr += 0x100;	/* next channel base */
1044 	}
1045 }
1046 
1047 static struct syscore_ops alchemy_dbdma_syscore_ops = {
1048 	.suspend	= alchemy_dbdma_suspend,
1049 	.resume		= alchemy_dbdma_resume,
1050 };
1051 
1052 static int __init dbdma_setup(unsigned int irq, dbdev_tab_t *idtable)
1053 {
1054 	int ret;
1055 
1056 	dbdev_tab = kcalloc(DBDEV_TAB_SIZE, sizeof(dbdev_tab_t), GFP_KERNEL);
1057 	if (!dbdev_tab)
1058 		return -ENOMEM;
1059 
1060 	memcpy(dbdev_tab, idtable, 32 * sizeof(dbdev_tab_t));
1061 	for (ret = 32; ret < DBDEV_TAB_SIZE; ret++)
1062 		dbdev_tab[ret].dev_id = ~0;
1063 
1064 	dbdma_gptr->ddma_config = 0;
1065 	dbdma_gptr->ddma_throttle = 0;
1066 	dbdma_gptr->ddma_inten = 0xffff;
1067 	wmb(); /* drain writebuffer */
1068 
1069 	ret = request_irq(irq, dbdma_interrupt, 0, "dbdma", (void *)dbdma_gptr);
1070 	if (ret)
1071 		printk(KERN_ERR "Cannot grab DBDMA interrupt!\n");
1072 	else {
1073 		dbdma_initialized = 1;
1074 		register_syscore_ops(&alchemy_dbdma_syscore_ops);
1075 	}
1076 
1077 	return ret;
1078 }
1079 
1080 static int __init alchemy_dbdma_init(void)
1081 {
1082 	switch (alchemy_get_cputype()) {
1083 	case ALCHEMY_CPU_AU1550:
1084 		return dbdma_setup(AU1550_DDMA_INT, au1550_dbdev_tab);
1085 	case ALCHEMY_CPU_AU1200:
1086 		return dbdma_setup(AU1200_DDMA_INT, au1200_dbdev_tab);
1087 	case ALCHEMY_CPU_AU1300:
1088 		return dbdma_setup(AU1300_DDMA_INT, au1300_dbdev_tab);
1089 	}
1090 	return 0;
1091 }
1092 subsys_initcall(alchemy_dbdma_init);
1093