2 * libata-sff.c - helper library for PCI IDE BMDMA
4 * Maintained by: Jeff Garzik <jgarzik@pobox.com>
5 * Please ALWAYS copy linux-ide@vger.kernel.org
8 * Copyright 2003-2006 Red Hat, Inc. All rights reserved.
9 * Copyright 2003-2006 Jeff Garzik
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2, or (at your option)
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; see the file COPYING. If not, write to
24 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
27 * libata documentation is available via 'make {ps|pdf}docs',
28 * as Documentation/DocBook/libata.*
30 * Hardware documentation available from http://www.t13.org/ and
31 * http://www.sata-io.org/
35 #include <linux/kernel.h>
36 #include <linux/pci.h>
37 #include <linux/libata.h>
42 * ata_irq_on - Enable interrupts on a port.
43 * @ap: Port on which interrupts are enabled.
45 * Enable interrupts on a legacy IDE device using MMIO or PIO,
46 * wait for idle, clear any pending interrupts.
49 * Inherited from caller.
51 u8 ata_irq_on(struct ata_port *ap)
53 struct ata_ioports *ioaddr = &ap->ioaddr;
57 ap->last_ctl = ap->ctl;
59 iowrite8(ap->ctl, ioaddr->ctl_addr);
60 tmp = ata_wait_idle(ap);
62 ap->ops->irq_clear(ap);
68 * ata_tf_load - send taskfile registers to host controller
69 * @ap: Port to which output is sent
70 * @tf: ATA taskfile register set
72 * Outputs ATA taskfile to standard ATA host controller.
75 * Inherited from caller.
78 void ata_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
80 struct ata_ioports *ioaddr = &ap->ioaddr;
81 unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
83 if (tf->ctl != ap->last_ctl) {
84 iowrite8(tf->ctl, ioaddr->ctl_addr);
85 ap->last_ctl = tf->ctl;
89 if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
90 iowrite8(tf->hob_feature, ioaddr->feature_addr);
91 iowrite8(tf->hob_nsect, ioaddr->nsect_addr);
92 iowrite8(tf->hob_lbal, ioaddr->lbal_addr);
93 iowrite8(tf->hob_lbam, ioaddr->lbam_addr);
94 iowrite8(tf->hob_lbah, ioaddr->lbah_addr);
95 VPRINTK("hob: feat 0x%X nsect 0x%X, lba 0x%X 0x%X 0x%X\n",
104 iowrite8(tf->feature, ioaddr->feature_addr);
105 iowrite8(tf->nsect, ioaddr->nsect_addr);
106 iowrite8(tf->lbal, ioaddr->lbal_addr);
107 iowrite8(tf->lbam, ioaddr->lbam_addr);
108 iowrite8(tf->lbah, ioaddr->lbah_addr);
109 VPRINTK("feat 0x%X nsect 0x%X lba 0x%X 0x%X 0x%X\n",
117 if (tf->flags & ATA_TFLAG_DEVICE) {
118 iowrite8(tf->device, ioaddr->device_addr);
119 VPRINTK("device 0x%X\n", tf->device);
126 * ata_exec_command - issue ATA command to host controller
127 * @ap: port to which command is being issued
128 * @tf: ATA taskfile register set
130 * Issues ATA command, with proper synchronization with interrupt
131 * handler / other threads.
134 * spin_lock_irqsave(host lock)
136 void ata_exec_command(struct ata_port *ap, const struct ata_taskfile *tf)
138 DPRINTK("ata%u: cmd 0x%X\n", ap->print_id, tf->command);
140 iowrite8(tf->command, ap->ioaddr.command_addr);
145 * ata_tf_read - input device's ATA taskfile shadow registers
146 * @ap: Port from which input is read
147 * @tf: ATA taskfile register set for storing input
149 * Reads ATA taskfile registers for currently-selected device
150 * into @tf. Assumes the device has a fully SFF compliant task file
151 * layout and behaviour. If you device does not (eg has a different
152 * status method) then you will need to provide a replacement tf_read
155 * Inherited from caller.
157 void ata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
159 struct ata_ioports *ioaddr = &ap->ioaddr;
161 tf->command = ata_check_status(ap);
162 tf->feature = ioread8(ioaddr->error_addr);
163 tf->nsect = ioread8(ioaddr->nsect_addr);
164 tf->lbal = ioread8(ioaddr->lbal_addr);
165 tf->lbam = ioread8(ioaddr->lbam_addr);
166 tf->lbah = ioread8(ioaddr->lbah_addr);
167 tf->device = ioread8(ioaddr->device_addr);
169 if (tf->flags & ATA_TFLAG_LBA48) {
170 iowrite8(tf->ctl | ATA_HOB, ioaddr->ctl_addr);
171 tf->hob_feature = ioread8(ioaddr->error_addr);
172 tf->hob_nsect = ioread8(ioaddr->nsect_addr);
173 tf->hob_lbal = ioread8(ioaddr->lbal_addr);
174 tf->hob_lbam = ioread8(ioaddr->lbam_addr);
175 tf->hob_lbah = ioread8(ioaddr->lbah_addr);
176 iowrite8(tf->ctl, ioaddr->ctl_addr);
177 ap->last_ctl = tf->ctl;
182 * ata_check_status - Read device status reg & clear interrupt
183 * @ap: port where the device is
185 * Reads ATA taskfile status register for currently-selected device
186 * and return its value. This also clears pending interrupts
190 * Inherited from caller.
192 u8 ata_check_status(struct ata_port *ap)
194 return ioread8(ap->ioaddr.status_addr);
198 * ata_altstatus - Read device alternate status reg
199 * @ap: port where the device is
201 * Reads ATA taskfile alternate status register for
202 * currently-selected device and return its value.
204 * Note: may NOT be used as the check_altstatus() entry in
205 * ata_port_operations.
208 * Inherited from caller.
210 u8 ata_altstatus(struct ata_port *ap)
212 if (ap->ops->check_altstatus)
213 return ap->ops->check_altstatus(ap);
215 return ioread8(ap->ioaddr.altstatus_addr);
219 * ata_bmdma_setup - Set up PCI IDE BMDMA transaction
220 * @qc: Info associated with this ATA transaction.
223 * spin_lock_irqsave(host lock)
225 void ata_bmdma_setup(struct ata_queued_cmd *qc)
227 struct ata_port *ap = qc->ap;
228 unsigned int rw = (qc->tf.flags & ATA_TFLAG_WRITE);
231 /* load PRD table addr. */
232 mb(); /* make sure PRD table writes are visible to controller */
233 iowrite32(ap->prd_dma, ap->ioaddr.bmdma_addr + ATA_DMA_TABLE_OFS);
235 /* specify data direction, triple-check start bit is clear */
236 dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
237 dmactl &= ~(ATA_DMA_WR | ATA_DMA_START);
239 dmactl |= ATA_DMA_WR;
240 iowrite8(dmactl, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
242 /* issue r/w command */
243 ap->ops->exec_command(ap, &qc->tf);
247 * ata_bmdma_start - Start a PCI IDE BMDMA transaction
248 * @qc: Info associated with this ATA transaction.
251 * spin_lock_irqsave(host lock)
253 void ata_bmdma_start(struct ata_queued_cmd *qc)
255 struct ata_port *ap = qc->ap;
258 /* start host DMA transaction */
259 dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
260 iowrite8(dmactl | ATA_DMA_START, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
262 /* Strictly, one may wish to issue an ioread8() here, to
263 * flush the mmio write. However, control also passes
264 * to the hardware at this point, and it will interrupt
265 * us when we are to resume control. So, in effect,
266 * we don't care when the mmio write flushes.
267 * Further, a read of the DMA status register _immediately_
268 * following the write may not be what certain flaky hardware
269 * is expected, so I think it is best to not add a readb()
270 * without first all the MMIO ATA cards/mobos.
271 * Or maybe I'm just being paranoid.
273 * FIXME: The posting of this write means I/O starts are
274 * unneccessarily delayed for MMIO
279 * ata_bmdma_irq_clear - Clear PCI IDE BMDMA interrupt.
280 * @ap: Port associated with this ATA transaction.
282 * Clear interrupt and error flags in DMA status register.
284 * May be used as the irq_clear() entry in ata_port_operations.
287 * spin_lock_irqsave(host lock)
289 void ata_bmdma_irq_clear(struct ata_port *ap)
291 void __iomem *mmio = ap->ioaddr.bmdma_addr;
296 iowrite8(ioread8(mmio + ATA_DMA_STATUS), mmio + ATA_DMA_STATUS);
300 * ata_bmdma_status - Read PCI IDE BMDMA status
301 * @ap: Port associated with this ATA transaction.
303 * Read and return BMDMA status register.
305 * May be used as the bmdma_status() entry in ata_port_operations.
308 * spin_lock_irqsave(host lock)
310 u8 ata_bmdma_status(struct ata_port *ap)
312 return ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
316 * ata_bmdma_stop - Stop PCI IDE BMDMA transfer
317 * @qc: Command we are ending DMA for
319 * Clears the ATA_DMA_START flag in the dma control register
321 * May be used as the bmdma_stop() entry in ata_port_operations.
324 * spin_lock_irqsave(host lock)
326 void ata_bmdma_stop(struct ata_queued_cmd *qc)
328 struct ata_port *ap = qc->ap;
329 void __iomem *mmio = ap->ioaddr.bmdma_addr;
331 /* clear start/stop bit */
332 iowrite8(ioread8(mmio + ATA_DMA_CMD) & ~ATA_DMA_START,
335 /* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
336 ata_altstatus(ap); /* dummy read */
340 * ata_bmdma_freeze - Freeze BMDMA controller port
341 * @ap: port to freeze
343 * Freeze BMDMA controller port.
346 * Inherited from caller.
348 void ata_bmdma_freeze(struct ata_port *ap)
350 struct ata_ioports *ioaddr = &ap->ioaddr;
353 ap->last_ctl = ap->ctl;
355 iowrite8(ap->ctl, ioaddr->ctl_addr);
357 /* Under certain circumstances, some controllers raise IRQ on
358 * ATA_NIEN manipulation. Also, many controllers fail to mask
359 * previously pending IRQ on ATA_NIEN assertion. Clear it.
363 ap->ops->irq_clear(ap);
367 * ata_bmdma_thaw - Thaw BMDMA controller port
370 * Thaw BMDMA controller port.
373 * Inherited from caller.
375 void ata_bmdma_thaw(struct ata_port *ap)
377 /* clear & re-enable interrupts */
379 ap->ops->irq_clear(ap);
384 * ata_bmdma_drive_eh - Perform EH with given methods for BMDMA controller
385 * @ap: port to handle error for
386 * @prereset: prereset method (can be NULL)
387 * @softreset: softreset method (can be NULL)
388 * @hardreset: hardreset method (can be NULL)
389 * @postreset: postreset method (can be NULL)
391 * Handle error for ATA BMDMA controller. It can handle both
392 * PATA and SATA controllers. Many controllers should be able to
393 * use this EH as-is or with some added handling before and
396 * This function is intended to be used for constructing
397 * ->error_handler callback by low level drivers.
400 * Kernel thread context (may sleep)
402 void ata_bmdma_drive_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
403 ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
404 ata_postreset_fn_t postreset)
406 struct ata_queued_cmd *qc;
410 qc = __ata_qc_from_tag(ap, ap->link.active_tag);
411 if (qc && !(qc->flags & ATA_QCFLAG_FAILED))
414 /* reset PIO HSM and stop DMA engine */
415 spin_lock_irqsave(ap->lock, flags);
417 ap->hsm_task_state = HSM_ST_IDLE;
419 if (qc && (qc->tf.protocol == ATA_PROT_DMA ||
420 qc->tf.protocol == ATAPI_PROT_DMA)) {
423 host_stat = ap->ops->bmdma_status(ap);
425 /* BMDMA controllers indicate host bus error by
426 * setting DMA_ERR bit and timing out. As it wasn't
427 * really a timeout event, adjust error mask and
428 * cancel frozen state.
430 if (qc->err_mask == AC_ERR_TIMEOUT && (host_stat & ATA_DMA_ERR)) {
431 qc->err_mask = AC_ERR_HOST_BUS;
435 ap->ops->bmdma_stop(qc);
440 ap->ops->irq_clear(ap);
442 spin_unlock_irqrestore(ap->lock, flags);
445 ata_eh_thaw_port(ap);
447 /* PIO and DMA engines have been stopped, perform recovery */
448 ata_do_eh(ap, prereset, softreset, hardreset, postreset);
452 * ata_bmdma_error_handler - Stock error handler for BMDMA controller
453 * @ap: port to handle error for
455 * Stock error handler for BMDMA controller.
458 * Kernel thread context (may sleep)
460 void ata_bmdma_error_handler(struct ata_port *ap)
462 ata_reset_fn_t hardreset;
465 if (sata_scr_valid(&ap->link))
466 hardreset = sata_std_hardreset;
468 ata_bmdma_drive_eh(ap, ata_std_prereset, ata_std_softreset, hardreset,
473 * ata_bmdma_post_internal_cmd - Stock post_internal_cmd for
475 * @qc: internal command to clean up
478 * Kernel thread context (may sleep)
480 void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc)
482 if (qc->ap->ioaddr.bmdma_addr)
487 * ata_sff_port_start - Set port up for dma.
488 * @ap: Port to initialize
490 * Called just after data structures for each port are
491 * initialized. Allocates space for PRD table if the device
492 * is DMA capable SFF.
494 * May be used as the port_start() entry in ata_port_operations.
497 * Inherited from caller.
500 int ata_sff_port_start(struct ata_port *ap)
502 if (ap->ioaddr.bmdma_addr)
503 return ata_port_start(ap);
509 static int ata_resources_present(struct pci_dev *pdev, int port)
513 /* Check the PCI resources for this channel are enabled */
515 for (i = 0; i < 2; i ++) {
516 if (pci_resource_start(pdev, port + i) == 0 ||
517 pci_resource_len(pdev, port + i) == 0)
524 * ata_pci_init_bmdma - acquire PCI BMDMA resources and init ATA host
525 * @host: target ATA host
527 * Acquire PCI BMDMA resources and initialize @host accordingly.
530 * Inherited from calling layer (may sleep).
533 * 0 on success, -errno otherwise.
535 int ata_pci_init_bmdma(struct ata_host *host)
537 struct device *gdev = host->dev;
538 struct pci_dev *pdev = to_pci_dev(gdev);
541 /* No BAR4 allocation: No DMA */
542 if (pci_resource_start(pdev, 4) == 0)
545 /* TODO: If we get no DMA mask we should fall back to PIO */
546 rc = pci_set_dma_mask(pdev, ATA_DMA_MASK);
549 rc = pci_set_consistent_dma_mask(pdev, ATA_DMA_MASK);
553 /* request and iomap DMA region */
554 rc = pcim_iomap_regions(pdev, 1 << 4, dev_driver_string(gdev));
556 dev_printk(KERN_ERR, gdev, "failed to request/iomap BAR4\n");
559 host->iomap = pcim_iomap_table(pdev);
561 for (i = 0; i < 2; i++) {
562 struct ata_port *ap = host->ports[i];
563 void __iomem *bmdma = host->iomap[4] + 8 * i;
565 if (ata_port_is_dummy(ap))
568 ap->ioaddr.bmdma_addr = bmdma;
569 if ((!(ap->flags & ATA_FLAG_IGN_SIMPLEX)) &&
570 (ioread8(bmdma + 2) & 0x80))
571 host->flags |= ATA_HOST_SIMPLEX;
573 ata_port_desc(ap, "bmdma 0x%llx",
574 (unsigned long long)pci_resource_start(pdev, 4) + 8 * i);
581 * ata_pci_init_sff_host - acquire native PCI ATA resources and init host
582 * @host: target ATA host
584 * Acquire native PCI ATA resources for @host and initialize the
585 * first two ports of @host accordingly. Ports marked dummy are
586 * skipped and allocation failure makes the port dummy.
588 * Note that native PCI resources are valid even for legacy hosts
589 * as we fix up pdev resources array early in boot, so this
590 * function can be used for both native and legacy SFF hosts.
593 * Inherited from calling layer (may sleep).
596 * 0 if at least one port is initialized, -ENODEV if no port is
599 int ata_pci_init_sff_host(struct ata_host *host)
601 struct device *gdev = host->dev;
602 struct pci_dev *pdev = to_pci_dev(gdev);
603 unsigned int mask = 0;
606 /* request, iomap BARs and init port addresses accordingly */
607 for (i = 0; i < 2; i++) {
608 struct ata_port *ap = host->ports[i];
610 void __iomem * const *iomap;
612 if (ata_port_is_dummy(ap))
615 /* Discard disabled ports. Some controllers show
616 * their unused channels this way. Disabled ports are
619 if (!ata_resources_present(pdev, i)) {
620 ap->ops = &ata_dummy_port_ops;
624 rc = pcim_iomap_regions(pdev, 0x3 << base,
625 dev_driver_string(gdev));
627 dev_printk(KERN_WARNING, gdev,
628 "failed to request/iomap BARs for port %d "
629 "(errno=%d)\n", i, rc);
631 pcim_pin_device(pdev);
632 ap->ops = &ata_dummy_port_ops;
635 host->iomap = iomap = pcim_iomap_table(pdev);
637 ap->ioaddr.cmd_addr = iomap[base];
638 ap->ioaddr.altstatus_addr =
639 ap->ioaddr.ctl_addr = (void __iomem *)
640 ((unsigned long)iomap[base + 1] | ATA_PCI_CTL_OFS);
641 ata_std_ports(&ap->ioaddr);
643 ata_port_desc(ap, "cmd 0x%llx ctl 0x%llx",
644 (unsigned long long)pci_resource_start(pdev, base),
645 (unsigned long long)pci_resource_start(pdev, base + 1));
651 dev_printk(KERN_ERR, gdev, "no available native port\n");
659 * ata_pci_prepare_sff_host - helper to prepare native PCI ATA host
660 * @pdev: target PCI device
661 * @ppi: array of port_info, must be enough for two ports
662 * @r_host: out argument for the initialized ATA host
664 * Helper to allocate ATA host for @pdev, acquire all native PCI
665 * resources and initialize it accordingly in one go.
668 * Inherited from calling layer (may sleep).
671 * 0 on success, -errno otherwise.
673 int ata_pci_prepare_sff_host(struct pci_dev *pdev,
674 const struct ata_port_info * const * ppi,
675 struct ata_host **r_host)
677 struct ata_host *host;
680 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL))
683 host = ata_host_alloc_pinfo(&pdev->dev, ppi, 2);
685 dev_printk(KERN_ERR, &pdev->dev,
686 "failed to allocate ATA host\n");
691 rc = ata_pci_init_sff_host(host);
695 /* init DMA related stuff */
696 rc = ata_pci_init_bmdma(host);
700 devres_remove_group(&pdev->dev, NULL);
705 /* This is necessary because PCI and iomap resources are
706 * merged and releasing the top group won't release the
707 * acquired resources if some of those have been acquired
708 * before entering this function.
710 pcim_iounmap_regions(pdev, 0xf);
712 devres_release_group(&pdev->dev, NULL);
717 * ata_pci_activate_sff_host - start SFF host, request IRQ and register it
718 * @host: target SFF ATA host
719 * @irq_handler: irq_handler used when requesting IRQ(s)
720 * @sht: scsi_host_template to use when registering the host
722 * This is the counterpart of ata_host_activate() for SFF ATA
723 * hosts. This separate helper is necessary because SFF hosts
724 * use two separate interrupts in legacy mode.
727 * Inherited from calling layer (may sleep).
730 * 0 on success, -errno otherwise.
732 int ata_pci_activate_sff_host(struct ata_host *host,
733 irq_handler_t irq_handler,
734 struct scsi_host_template *sht)
736 struct device *dev = host->dev;
737 struct pci_dev *pdev = to_pci_dev(dev);
738 const char *drv_name = dev_driver_string(host->dev);
739 int legacy_mode = 0, rc;
741 rc = ata_host_start(host);
745 if ((pdev->class >> 8) == PCI_CLASS_STORAGE_IDE) {
748 /* TODO: What if one channel is in native mode ... */
749 pci_read_config_byte(pdev, PCI_CLASS_PROG, &tmp8);
750 mask = (1 << 2) | (1 << 0);
751 if ((tmp8 & mask) != mask)
753 #if defined(CONFIG_NO_ATA_LEGACY)
754 /* Some platforms with PCI limits cannot address compat
755 port space. In that case we punt if their firmware has
756 left a device in compatibility mode */
758 printk(KERN_ERR "ata: Compatibility mode ATA is not supported on this platform, skipping.\n");
764 if (!devres_open_group(dev, NULL, GFP_KERNEL))
767 if (!legacy_mode && pdev->irq) {
768 rc = devm_request_irq(dev, pdev->irq, irq_handler,
769 IRQF_SHARED, drv_name, host);
773 ata_port_desc(host->ports[0], "irq %d", pdev->irq);
774 ata_port_desc(host->ports[1], "irq %d", pdev->irq);
775 } else if (legacy_mode) {
776 if (!ata_port_is_dummy(host->ports[0])) {
777 rc = devm_request_irq(dev, ATA_PRIMARY_IRQ(pdev),
778 irq_handler, IRQF_SHARED,
783 ata_port_desc(host->ports[0], "irq %d",
784 ATA_PRIMARY_IRQ(pdev));
787 if (!ata_port_is_dummy(host->ports[1])) {
788 rc = devm_request_irq(dev, ATA_SECONDARY_IRQ(pdev),
789 irq_handler, IRQF_SHARED,
794 ata_port_desc(host->ports[1], "irq %d",
795 ATA_SECONDARY_IRQ(pdev));
799 rc = ata_host_register(host, sht);
802 devres_remove_group(dev, NULL);
804 devres_release_group(dev, NULL);
810 * ata_pci_init_one - Initialize/register PCI IDE host controller
811 * @pdev: Controller to be initialized
812 * @ppi: array of port_info, must be enough for two ports
814 * This is a helper function which can be called from a driver's
815 * xxx_init_one() probe function if the hardware uses traditional
816 * IDE taskfile registers.
818 * This function calls pci_enable_device(), reserves its register
819 * regions, sets the dma mask, enables bus master mode, and calls
823 * Nobody makes a single channel controller that appears solely as
824 * the secondary legacy port on PCI.
827 * Inherited from PCI layer (may sleep).
830 * Zero on success, negative on errno-based value on error.
832 int ata_pci_init_one(struct pci_dev *pdev,
833 const struct ata_port_info * const * ppi)
835 struct device *dev = &pdev->dev;
836 const struct ata_port_info *pi = NULL;
837 struct ata_host *host = NULL;
842 /* look up the first valid port_info */
843 for (i = 0; i < 2 && ppi[i]; i++) {
844 if (ppi[i]->port_ops != &ata_dummy_port_ops) {
851 dev_printk(KERN_ERR, &pdev->dev,
852 "no valid port_info specified\n");
856 if (!devres_open_group(dev, NULL, GFP_KERNEL))
859 rc = pcim_enable_device(pdev);
863 /* prepare and activate SFF host */
864 rc = ata_pci_prepare_sff_host(pdev, ppi, &host);
868 pci_set_master(pdev);
869 rc = ata_pci_activate_sff_host(host, pi->port_ops->irq_handler,
873 devres_remove_group(&pdev->dev, NULL);
875 devres_release_group(&pdev->dev, NULL);
881 * ata_pci_clear_simplex - attempt to kick device out of simplex
884 * Some PCI ATA devices report simplex mode but in fact can be told to
885 * enter non simplex mode. This implements the necessary logic to
886 * perform the task on such devices. Calling it on other devices will
887 * have -undefined- behaviour.
890 int ata_pci_clear_simplex(struct pci_dev *pdev)
892 unsigned long bmdma = pci_resource_start(pdev, 4);
898 simplex = inb(bmdma + 0x02);
899 outb(simplex & 0x60, bmdma + 0x02);
900 simplex = inb(bmdma + 0x02);
906 unsigned long ata_pci_default_filter(struct ata_device *adev, unsigned long xfer_mask)
908 /* Filter out DMA modes if the device has been configured by
909 the BIOS as PIO only */
911 if (adev->link->ap->ioaddr.bmdma_addr == NULL)
912 xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
916 #endif /* CONFIG_PCI */