2 * arch/ppc/kernel/ppc4xx_dma.c
4 * IBM PPC4xx DMA engine core library
6 * Copyright 2000-2004 MontaVista Software Inc.
8 * Cleaned up and converted to new DCR access
9 * Matt Porter <mporter@kernel.crashing.org>
11 * Original code by Armin Kuster <akuster@mvista.com>
12 * and Pete Popov <ppopov@mvista.com>
14 * This program is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License as published by the
16 * Free Software Foundation; either version 2 of the License, or (at your
17 * option) any later version.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <linux/config.h>
25 #include <linux/kernel.h>
27 #include <linux/miscdevice.h>
28 #include <linux/init.h>
29 #include <linux/module.h>
31 #include <asm/system.h>
33 #include <asm/ppc4xx_dma.h>
35 ppc_dma_ch_t dma_channels[MAX_PPC4xx_DMA_CHANNELS];
38 ppc4xx_get_dma_status(void)
40 return (mfdcr(DCRN_DMASR));
44 ppc4xx_set_src_addr(int dmanr, phys_addr_t src_addr)
46 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
47 printk("set_src_addr: bad channel: %d\n", dmanr);
51 #ifdef PPC4xx_DMA_64BIT
52 mtdcr(DCRN_DMASAH0 + dmanr*2, (u32)(src_addr >> 32));
54 mtdcr(DCRN_DMASA0 + dmanr*2, (u32)src_addr);
59 ppc4xx_set_dst_addr(int dmanr, phys_addr_t dst_addr)
61 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
62 printk("set_dst_addr: bad channel: %d\n", dmanr);
66 #ifdef PPC4xx_DMA_64BIT
67 mtdcr(DCRN_DMADAH0 + dmanr*2, (u32)(dst_addr >> 32));
69 mtdcr(DCRN_DMADA0 + dmanr*2, (u32)dst_addr);
74 ppc4xx_enable_dma(unsigned int dmanr)
77 ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
78 unsigned int status_bits[] = { DMA_CS0 | DMA_TS0 | DMA_CH0_ERR,
79 DMA_CS1 | DMA_TS1 | DMA_CH1_ERR,
80 DMA_CS2 | DMA_TS2 | DMA_CH2_ERR,
81 DMA_CS3 | DMA_TS3 | DMA_CH3_ERR};
83 if (p_dma_ch->in_use) {
84 printk("enable_dma: channel %d in use\n", dmanr);
88 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
89 printk("enable_dma: bad channel: %d\n", dmanr);
93 if (p_dma_ch->mode == DMA_MODE_READ) {
94 /* peripheral to memory */
95 ppc4xx_set_src_addr(dmanr, 0);
96 ppc4xx_set_dst_addr(dmanr, p_dma_ch->addr);
97 } else if (p_dma_ch->mode == DMA_MODE_WRITE) {
98 /* memory to peripheral */
99 ppc4xx_set_src_addr(dmanr, p_dma_ch->addr);
100 ppc4xx_set_dst_addr(dmanr, 0);
103 /* for other xfer modes, the addresses are already set */
104 control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
106 control &= ~(DMA_TM_MASK | DMA_TD); /* clear all mode bits */
107 if (p_dma_ch->mode == DMA_MODE_MM) {
108 /* software initiated memory to memory */
109 control |= DMA_ETD_OUTPUT | DMA_TCE_ENABLE;
112 mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
115 * Clear the CS, TS, RI bits for the channel from DMASR. This
116 * has been observed to happen correctly only after the mode and
117 * ETD/DCE bits in DMACRx are set above. Must do this before
118 * enabling the channel.
121 mtdcr(DCRN_DMASR, status_bits[dmanr]);
124 * For device-paced transfers, Terminal Count Enable apparently
125 * must be on, and this must be turned on after the mode, etc.
126 * bits are cleared above (at least on Redwood-6).
129 if ((p_dma_ch->mode == DMA_MODE_MM_DEVATDST) ||
130 (p_dma_ch->mode == DMA_MODE_MM_DEVATSRC))
131 control |= DMA_TCE_ENABLE;
134 * Now enable the channel.
137 control |= (p_dma_ch->mode | DMA_CE_ENABLE);
139 mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
141 p_dma_ch->in_use = 1;
145 ppc4xx_disable_dma(unsigned int dmanr)
147 unsigned int control;
148 ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
150 if (!p_dma_ch->in_use) {
151 printk("disable_dma: channel %d not in use\n", dmanr);
155 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
156 printk("disable_dma: bad channel: %d\n", dmanr);
160 control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
161 control &= ~DMA_CE_ENABLE;
162 mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
164 p_dma_ch->in_use = 0;
168 * Sets the dma mode for single DMA transfers only.
169 * For scatter/gather transfers, the mode is passed to the
170 * alloc_dma_handle() function as one of the parameters.
172 * The mode is simply saved and used later. This allows
173 * the driver to call set_dma_mode() and set_dma_addr() in
176 * Valid mode values are:
178 * DMA_MODE_READ peripheral to memory
179 * DMA_MODE_WRITE memory to peripheral
180 * DMA_MODE_MM memory to memory
181 * DMA_MODE_MM_DEVATSRC device-paced memory to memory, device at src
182 * DMA_MODE_MM_DEVATDST device-paced memory to memory, device at dst
185 ppc4xx_set_dma_mode(unsigned int dmanr, unsigned int mode)
187 ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
189 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
190 printk("set_dma_mode: bad channel 0x%x\n", dmanr);
191 return DMA_STATUS_BAD_CHANNEL;
194 p_dma_ch->mode = mode;
196 return DMA_STATUS_GOOD;
200 * Sets the DMA Count register. Note that 'count' is in bytes.
201 * However, the DMA Count register counts the number of "transfers",
202 * where each transfer is equal to the bus width. Thus, count
203 * MUST be a multiple of the bus width.
206 ppc4xx_set_dma_count(unsigned int dmanr, unsigned int count)
208 ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
213 switch (p_dma_ch->pwidth) {
229 printk("set_dma_count: invalid bus width: 0x%x\n",
235 ("Warning: set_dma_count count 0x%x bus width %d\n",
236 count, p_dma_ch->pwidth);
240 count = count >> p_dma_ch->shift;
242 mtdcr(DCRN_DMACT0 + (dmanr * 0x8), count);
246 * Returns the number of bytes left to be transfered.
247 * After a DMA transfer, this should return zero.
248 * Reading this while a DMA transfer is still in progress will return
249 * unpredictable results.
252 ppc4xx_get_dma_residue(unsigned int dmanr)
255 ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
257 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
258 printk("ppc4xx_get_dma_residue: bad channel 0x%x\n", dmanr);
259 return DMA_STATUS_BAD_CHANNEL;
262 count = mfdcr(DCRN_DMACT0 + (dmanr * 0x8));
264 return (count << p_dma_ch->shift);
268 * Sets the DMA address for a memory to peripheral or peripheral
269 * to memory transfer. The address is just saved in the channel
270 * structure for now and used later in enable_dma().
273 ppc4xx_set_dma_addr(unsigned int dmanr, phys_addr_t addr)
275 ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
277 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
278 printk("ppc4xx_set_dma_addr: bad channel: %d\n", dmanr);
285 switch (p_dma_ch->pwidth) {
289 if ((unsigned) addr & 0x1)
293 if ((unsigned) addr & 0x3)
297 if ((unsigned) addr & 0x7)
301 printk("ppc4xx_set_dma_addr: invalid bus width: 0x%x\n",
306 printk("Warning: ppc4xx_set_dma_addr addr 0x%x bus width %d\n",
307 addr, p_dma_ch->pwidth);
311 /* save dma address and program it later after we know the xfer mode */
312 p_dma_ch->addr = addr;
316 * Sets both DMA addresses for a memory to memory transfer.
317 * For memory to peripheral or peripheral to memory transfers
318 * the function set_dma_addr() should be used instead.
321 ppc4xx_set_dma_addr2(unsigned int dmanr, phys_addr_t src_dma_addr,
322 phys_addr_t dst_dma_addr)
324 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
325 printk("ppc4xx_set_dma_addr2: bad channel: %d\n", dmanr);
331 ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
333 switch (p_dma_ch->pwidth) {
337 if (((unsigned) src_dma_addr & 0x1) ||
338 ((unsigned) dst_dma_addr & 0x1)
343 if (((unsigned) src_dma_addr & 0x3) ||
344 ((unsigned) dst_dma_addr & 0x3)
349 if (((unsigned) src_dma_addr & 0x7) ||
350 ((unsigned) dst_dma_addr & 0x7)
355 printk("ppc4xx_set_dma_addr2: invalid bus width: 0x%x\n",
361 ("Warning: ppc4xx_set_dma_addr2 src 0x%x dst 0x%x bus width %d\n",
362 src_dma_addr, dst_dma_addr, p_dma_ch->pwidth);
366 ppc4xx_set_src_addr(dmanr, src_dma_addr);
367 ppc4xx_set_dst_addr(dmanr, dst_dma_addr);
371 * Enables the channel interrupt.
373 * If performing a scatter/gatter transfer, this function
374 * MUST be called before calling alloc_dma_handle() and building
375 * the sgl list. Otherwise, interrupts will not be enabled, if
376 * they were previously disabled.
379 ppc4xx_enable_dma_interrupt(unsigned int dmanr)
381 unsigned int control;
382 ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
384 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
385 printk("ppc4xx_enable_dma_interrupt: bad channel: %d\n", dmanr);
386 return DMA_STATUS_BAD_CHANNEL;
389 p_dma_ch->int_enable = 1;
391 control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
392 control |= DMA_CIE_ENABLE; /* Channel Interrupt Enable */
393 mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
395 return DMA_STATUS_GOOD;
399 * Disables the channel interrupt.
401 * If performing a scatter/gatter transfer, this function
402 * MUST be called before calling alloc_dma_handle() and building
403 * the sgl list. Otherwise, interrupts will not be disabled, if
404 * they were previously enabled.
407 ppc4xx_disable_dma_interrupt(unsigned int dmanr)
409 unsigned int control;
410 ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
412 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
413 printk("ppc4xx_disable_dma_interrupt: bad channel: %d\n", dmanr);
414 return DMA_STATUS_BAD_CHANNEL;
417 p_dma_ch->int_enable = 0;
419 control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
420 control &= ~DMA_CIE_ENABLE; /* Channel Interrupt Enable */
421 mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
423 return DMA_STATUS_GOOD;
427 * Configures a DMA channel, including the peripheral bus width, if a
428 * peripheral is attached to the channel, the polarity of the DMAReq and
429 * DMAAck signals, etc. This information should really be setup by the boot
430 * code, since most likely the configuration won't change dynamically.
431 * If the kernel has to call this function, it's recommended that it's
432 * called from platform specific init code. The driver should not need to
433 * call this function.
436 ppc4xx_init_dma_channel(unsigned int dmanr, ppc_dma_ch_t * p_init)
438 unsigned int polarity;
439 uint32_t control = 0;
440 ppc_dma_ch_t *p_dma_ch = &dma_channels[dmanr];
442 DMA_MODE_READ = (unsigned long) DMA_TD; /* Peripheral to Memory */
443 DMA_MODE_WRITE = 0; /* Memory to Peripheral */
446 printk("ppc4xx_init_dma_channel: NULL p_init\n");
447 return DMA_STATUS_NULL_POINTER;
450 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
451 printk("ppc4xx_init_dma_channel: bad channel %d\n", dmanr);
452 return DMA_STATUS_BAD_CHANNEL;
456 polarity = mfdcr(DCRN_POL);
461 /* Setup the control register based on the values passed to
462 * us in p_init. Then, over-write the control register with this
465 control |= SET_DMA_CONTROL;
467 /* clear all polarity signals and then "or" in new signal levels */
468 polarity &= ~GET_DMA_POLARITY(dmanr);
469 polarity |= p_init->polarity;
471 mtdcr(DCRN_POL, polarity);
473 mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
475 /* save these values in our dma channel structure */
476 memcpy(p_dma_ch, p_init, sizeof (ppc_dma_ch_t));
479 * The peripheral width values written in the control register are:
485 * Since the DMA count register takes the number of "transfers",
486 * we need to divide the count sent to us in certain
487 * functions by the appropriate number. It so happens that our
488 * right shift value is equal to the peripheral width value.
490 p_dma_ch->shift = p_init->pwidth;
493 * Save the control word for easy access.
495 p_dma_ch->control = control;
497 mtdcr(DCRN_DMASR, 0xffffffff); /* clear status register */
498 return DMA_STATUS_GOOD;
502 * This function returns the channel configuration.
505 ppc4xx_get_channel_config(unsigned int dmanr, ppc_dma_ch_t * p_dma_ch)
507 unsigned int polarity;
508 unsigned int control;
510 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
511 printk("ppc4xx_get_channel_config: bad channel %d\n", dmanr);
512 return DMA_STATUS_BAD_CHANNEL;
515 memcpy(p_dma_ch, &dma_channels[dmanr], sizeof (ppc_dma_ch_t));
518 polarity = mfdcr(DCRN_POL);
523 p_dma_ch->polarity = polarity & GET_DMA_POLARITY(dmanr);
524 control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
526 p_dma_ch->cp = GET_DMA_PRIORITY(control);
527 p_dma_ch->pwidth = GET_DMA_PW(control);
528 p_dma_ch->psc = GET_DMA_PSC(control);
529 p_dma_ch->pwc = GET_DMA_PWC(control);
530 p_dma_ch->phc = GET_DMA_PHC(control);
531 p_dma_ch->ce = GET_DMA_CE_ENABLE(control);
532 p_dma_ch->int_enable = GET_DMA_CIE_ENABLE(control);
533 p_dma_ch->shift = GET_DMA_PW(control);
535 #ifdef CONFIG_PPC4xx_EDMA
536 p_dma_ch->pf = GET_DMA_PREFETCH(control);
538 p_dma_ch->ch_enable = GET_DMA_CH(control);
539 p_dma_ch->ece_enable = GET_DMA_ECE(control);
540 p_dma_ch->tcd_disable = GET_DMA_TCD(control);
542 return DMA_STATUS_GOOD;
546 * Sets the priority for the DMA channel dmanr.
547 * Since this is setup by the hardware init function, this function
548 * can be used to dynamically change the priority of a channel.
550 * Acceptable priorities:
559 ppc4xx_set_channel_priority(unsigned int dmanr, unsigned int priority)
561 unsigned int control;
563 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
564 printk("ppc4xx_set_channel_priority: bad channel %d\n", dmanr);
565 return DMA_STATUS_BAD_CHANNEL;
568 if ((priority != PRIORITY_LOW) &&
569 (priority != PRIORITY_MID_LOW) &&
570 (priority != PRIORITY_MID_HIGH) && (priority != PRIORITY_HIGH)) {
571 printk("ppc4xx_set_channel_priority: bad priority: 0x%x\n", priority);
574 control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
575 control |= SET_DMA_PRIORITY(priority);
576 mtdcr(DCRN_DMACR0 + (dmanr * 0x8), control);
578 return DMA_STATUS_GOOD;
582 * Returns the width of the peripheral attached to this channel. This assumes
583 * that someone who knows the hardware configuration, boot code or some other
584 * init code, already set the width.
586 * The return value is one of:
592 * The function returns 0 on error.
595 ppc4xx_get_peripheral_width(unsigned int dmanr)
597 unsigned int control;
599 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
600 printk("ppc4xx_get_peripheral_width: bad channel %d\n", dmanr);
601 return DMA_STATUS_BAD_CHANNEL;
604 control = mfdcr(DCRN_DMACR0 + (dmanr * 0x8));
606 return (GET_DMA_PW(control));
610 * Clears the channel status bits
613 ppc4xx_clr_dma_status(unsigned int dmanr)
615 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
616 printk(KERN_ERR "ppc4xx_clr_dma_status: bad channel: %d\n", dmanr);
617 return DMA_STATUS_BAD_CHANNEL;
619 mtdcr(DCRN_DMASR, ((u32)DMA_CH0_ERR | (u32)DMA_CS0 | (u32)DMA_TS0) >> dmanr);
620 return DMA_STATUS_GOOD;
623 #ifdef CONFIG_PPC4xx_EDMA
625 * Enables the burst on the channel (BTEN bit in the control/count register)
627 * For scatter/gather dma, this function MUST be called before the
628 * ppc4xx_alloc_dma_handle() func as the chan count register is copied into the
629 * sgl list and used as each sgl element is added.
632 ppc4xx_enable_burst(unsigned int dmanr)
635 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
636 printk(KERN_ERR "ppc4xx_enable_burst: bad channel: %d\n", dmanr);
637 return DMA_STATUS_BAD_CHANNEL;
639 ctc = mfdcr(DCRN_DMACT0 + (dmanr * 0x8)) | DMA_CTC_BTEN;
640 mtdcr(DCRN_DMACT0 + (dmanr * 0x8), ctc);
641 return DMA_STATUS_GOOD;
644 * Disables the burst on the channel (BTEN bit in the control/count register)
646 * For scatter/gather dma, this function MUST be called before the
647 * ppc4xx_alloc_dma_handle() func as the chan count register is copied into the
648 * sgl list and used as each sgl element is added.
651 ppc4xx_disable_burst(unsigned int dmanr)
654 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
655 printk(KERN_ERR "ppc4xx_disable_burst: bad channel: %d\n", dmanr);
656 return DMA_STATUS_BAD_CHANNEL;
658 ctc = mfdcr(DCRN_DMACT0 + (dmanr * 0x8)) &~ DMA_CTC_BTEN;
659 mtdcr(DCRN_DMACT0 + (dmanr * 0x8), ctc);
660 return DMA_STATUS_GOOD;
663 * Sets the burst size (number of peripheral widths) for the channel
664 * (BSIZ bits in the control/count register))
671 * For scatter/gather dma, this function MUST be called before the
672 * ppc4xx_alloc_dma_handle() func as the chan count register is copied into the
673 * sgl list and used as each sgl element is added.
676 ppc4xx_set_burst_size(unsigned int dmanr, unsigned int bsize)
679 if (dmanr >= MAX_PPC4xx_DMA_CHANNELS) {
680 printk(KERN_ERR "ppc4xx_set_burst_size: bad channel: %d\n", dmanr);
681 return DMA_STATUS_BAD_CHANNEL;
683 ctc = mfdcr(DCRN_DMACT0 + (dmanr * 0x8)) &~ DMA_CTC_BSIZ_MSK;
684 ctc |= (bsize & DMA_CTC_BSIZ_MSK);
685 mtdcr(DCRN_DMACT0 + (dmanr * 0x8), ctc);
686 return DMA_STATUS_GOOD;
689 EXPORT_SYMBOL(ppc4xx_enable_burst);
690 EXPORT_SYMBOL(ppc4xx_disable_burst);
691 EXPORT_SYMBOL(ppc4xx_set_burst_size);
692 #endif /* CONFIG_PPC4xx_EDMA */
694 EXPORT_SYMBOL(ppc4xx_init_dma_channel);
695 EXPORT_SYMBOL(ppc4xx_get_channel_config);
696 EXPORT_SYMBOL(ppc4xx_set_channel_priority);
697 EXPORT_SYMBOL(ppc4xx_get_peripheral_width);
698 EXPORT_SYMBOL(dma_channels);
699 EXPORT_SYMBOL(ppc4xx_set_src_addr);
700 EXPORT_SYMBOL(ppc4xx_set_dst_addr);
701 EXPORT_SYMBOL(ppc4xx_set_dma_addr);
702 EXPORT_SYMBOL(ppc4xx_set_dma_addr2);
703 EXPORT_SYMBOL(ppc4xx_enable_dma);
704 EXPORT_SYMBOL(ppc4xx_disable_dma);
705 EXPORT_SYMBOL(ppc4xx_set_dma_mode);
706 EXPORT_SYMBOL(ppc4xx_set_dma_count);
707 EXPORT_SYMBOL(ppc4xx_get_dma_residue);
708 EXPORT_SYMBOL(ppc4xx_enable_dma_interrupt);
709 EXPORT_SYMBOL(ppc4xx_disable_dma_interrupt);
710 EXPORT_SYMBOL(ppc4xx_get_dma_status);
711 EXPORT_SYMBOL(ppc4xx_clr_dma_status);