pata_ns87415: Initial cut at 87415/87560 IDE support

Signed-off-by: Alan Cox <alan@redhat.com>
[plus SuperIO fixes by Kyle McMartin]
[plus a cleanup from me]
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 467 insertions, 0 deletions

diff --git a/drivers/ata/pata_ns87415.c b/drivers/ata/pata_ns87415.c
new file mode 100644
index 000000000000..bb97ef583f9b
--- /dev/null
+++ b/drivers/ata/pata_ns87415.c
@@ -0,0 +1,467 @@
+/*
+ *    pata_ns87415.c - NS87415 (non PARISC) PATA
+ *
+ *	(C) 2005 Red Hat <alan@redhat.com>
+ *
+ *    This is a fairly generic MWDMA controller. It has some limitations
+ *    as it requires timing reloads on PIO/DMA transitions but it is otherwise
+ *    fairly well designed.
+ *
+ *    This driver assumes the firmware has left the chip in a valid ST506
+ *    compliant state, either legacy IRQ 14/15 or native INTA shared. You
+ *    may need to add platform code if your system fails to do this.
+ *
+ *    The same cell appears in the 87560 controller used by some PARISC
+ *    systems. This has its own special mountain of errata.
+ *
+ *    TODO:
+ *	Test PARISC SuperIO
+ *	Get someone to test on SPARC
+ *	Implement lazy pio/dma switching for better performance	
+ *	8bit shared timing.
+ *	See if we need to kill the FIFO for ATAPI
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <scsi/scsi_host.h>
+#include <linux/libata.h>
+#include <linux/ata.h>
+
+#define DRV_NAME	"pata_ns87415"
+#define DRV_VERSION	"0.0.1"
+
+/**
+ *	ns87415_set_mode - Initialize host controller mode timings
+ *	@ap: Port whose timings we are configuring
+ *	@adev: Device whose timings we are configuring
+ *	@mode: Mode to set
+ *
+ *	Program the mode registers for this controller, channel and
+ *	device. Because the chip is quite an old design we have to do this
+ *	for PIO/DMA switches.
+ *
+ *	LOCKING:
+ *	None (inherited from caller).
+ */
+
+static void ns87415_set_mode(struct ata_port *ap, struct ata_device *adev, u8 mode)
+{
+	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
+	int unit		= 2 * ap->port_no + adev->devno;
+	int timing		= 0x44 + 2 * unit;
+	unsigned long T		= 1000000000 / 33333;	/* PCI clocks */
+	struct ata_timing t;
+	u16 clocking;
+	u8 iordy;
+	u8 status;
+	
+	/* Timing register format is 17 - low nybble read timing with
+	   the high nybble being 16 - x for recovery time in PCI clocks */
+   
+	ata_timing_compute(adev, adev->pio_mode, &t, T, 0);
+
+	clocking = 17 - FIT(t.active, 2, 17);
+	clocking |= (16 - FIT(t.recover, 1, 16)) << 4;
+ 	/* Use the same timing for read and write bytes */
+	clocking |= (clocking << 8);
+	pci_write_config_word(dev, timing, clocking);
+	
+	/* Set the IORDY enable versus DMA enable on or off properly */
+	pci_read_config_byte(dev, 0x42, &iordy);
+	iordy &= ~(1 << (4 + unit));
+	if (mode >= XFER_MW_DMA_0 || !ata_pio_need_iordy(adev))
+		iordy |= (1 << (4 + unit));
+
+	/* Paranoia: We shouldn't ever get here with busy write buffers
+	   but if so wait */
+
+	pci_read_config_byte(dev, 0x43, &status);
+	while (status & 0x03) {
+		udelay(1);
+		pci_read_config_byte(dev, 0x43, &status);
+	}
+	/* Flip the IORDY/DMA bits now we are sure the write buffers are
+	   clear */
+	pci_write_config_byte(dev, 0x42, iordy);
+
+	/* TODO: Set byte 54 command timing to the best 8bit
+	   mode shared by all four devices */
+}
+
+/**
+ *	ns87415_set_piomode - Initialize host controller PATA PIO timings
+ *	@ap: Port whose timings we are configuring
+ *	@adev: Device to program
+ *
+ *	Set PIO mode for device, in host controller PCI config space.
+ *
+ *	LOCKING:
+ *	None (inherited from caller).
+ */
+
+static void ns87415_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+	ns87415_set_mode(ap, adev, adev->pio_mode);
+}
+
+/**
+ *	ns87415_bmdma_setup		-	Set up DMA
+ *	@qc: Command block
+ *
+ *	Set up for bus masterng DMA. We have to do this ourselves
+ *	rather than use the helper due to a chip erratum
+ */
+
+static void ns87415_bmdma_setup(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+	unsigned int rw = (qc->tf.flags & ATA_TFLAG_WRITE);
+	u8 dmactl;
+
+	/* load PRD table addr. */
+	mb();	/* make sure PRD table writes are visible to controller */
+	iowrite32(ap->prd_dma, ap->ioaddr.bmdma_addr + ATA_DMA_TABLE_OFS);
+
+	/* specify data direction, triple-check start bit is clear */
+	dmactl = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
+	dmactl &= ~(ATA_DMA_WR | ATA_DMA_START);
+	/* Due to an erratum we need to write these bits to the wrong
+	   place - which does save us an I/O bizarrely */
+	dmactl |= ATA_DMA_INTR | ATA_DMA_ERR;
+	if (!rw)
+		dmactl |= ATA_DMA_WR;
+	iowrite8(dmactl, ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
+	/* issue r/w command */
+	ap->ops->exec_command(ap, &qc->tf);
+}
+
+/**
+ *	ns87415_bmdma_start		-	Begin DMA transfer
+ *	@qc: Command block
+ *
+ *	Switch the timings for the chip and set up for a DMA transfer
+ *	before the DMA burst begins.
+ *
+ *	FIXME: We should do lazy switching on bmdma_start versus
+ *	ata_pio_data_xfer for better performance.
+ */
+
+static void ns87415_bmdma_start(struct ata_queued_cmd *qc)
+{
+	ns87415_set_mode(qc->ap, qc->dev, qc->dev->dma_mode);
+	ata_bmdma_start(qc);
+}
+
+/**
+ *	ns87415_bmdma_stop		-	End DMA transfer
+ *	@qc: Command block
+ *
+ *	End DMA mode and switch the controller back into PIO mode
+ */
+
+static void ns87415_bmdma_stop(struct ata_queued_cmd *qc)
+{
+	ata_bmdma_stop(qc);
+	ns87415_set_mode(qc->ap, qc->dev, qc->dev->pio_mode);
+}
+
+/**
+ *	ns87415_bmdma_irq_clear		-	Clear interrupt
+ *	@ap: Channel to clear
+ *
+ *	Erratum: Due to a chip bug regisers 02 and 0A bit 1 and 2 (the
+ *	error bits) are reset by writing to register 00 or 08.
+ */
+
+static void ns87415_bmdma_irq_clear(struct ata_port *ap)
+{
+	void __iomem *mmio = ap->ioaddr.bmdma_addr;
+
+	if (!mmio)
+		return;
+	iowrite8((ioread8(mmio + ATA_DMA_CMD) | ATA_DMA_INTR | ATA_DMA_ERR), 
+			mmio + ATA_DMA_CMD);
+}
+
+/**
+ *	ns87415_check_atapi_dma		-	ATAPI DMA filter
+ *	@qc: Command block
+ *
+ *	Disable ATAPI DMA (for now). We may be able to do DMA if we
+ *	kill the prefetching. This isn't clear.
+ */
+
+static int ns87415_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+	return -EOPNOTSUPP;
+}
+
+#if defined(CONFIG_SUPERIO)
+
+/* SUPERIO 87560 is a PoS chip that NatSem denies exists.
+ * Unfortunately, it's built-in on all Astro-based PA-RISC workstations
+ * which use the integrated NS87514 cell for CD-ROM support.
+ * i.e we have to support for CD-ROM installs.
+ * See drivers/parisc/superio.c for more gory details.
+ *
+ * Workarounds taken from drivers/ide/pci/ns87415.c
+ */
+
+#include <asm/superio.h>
+
+/**
+ *	ns87560_read_buggy	-	workaround buggy Super I/O chip
+ *	@port: Port to read
+ *
+ *	Work around chipset problems in the 87560 SuperIO chip
+ */
+
+static u8 ns87560_read_buggy(void __iomem *port)
+{
+	u8 tmp;
+	int retries = SUPERIO_IDE_MAX_RETRIES;
+	do {
+		tmp = ioread8(port);
+		if (tmp != 0)
+			return tmp;
+		udelay(50);
+	} while(retries-- > 0);
+	return tmp;
+}
+
+/**
+ *	ns87560_check_status
+ *	@ap: channel to check
+ *
+ *	Return the status of the channel working around the
+ *	87560 flaws.
+ */
+
+static u8 ns87560_check_status(struct ata_port *ap)
+{
+	return ns87560_read_buggy(ap->ioaddr.status_addr);
+}
+
+/**
+ *	ns87560_tf_read - input device's ATA taskfile shadow registers
+ *	@ap: Port from which input is read
+ *	@tf: ATA taskfile register set for storing input
+ *
+ *	Reads ATA taskfile registers for currently-selected device
+ *	into @tf. Work around the 87560 bugs.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+void ns87560_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
+{
+	struct ata_ioports *ioaddr = &ap->ioaddr;
+
+	tf->command = ns87560_check_status(ap);
+	tf->feature = ioread8(ioaddr->error_addr);
+	tf->nsect = ioread8(ioaddr->nsect_addr);
+	tf->lbal = ioread8(ioaddr->lbal_addr);
+	tf->lbam = ioread8(ioaddr->lbam_addr);
+	tf->lbah = ioread8(ioaddr->lbah_addr);
+	tf->device = ns87560_read_buggy(ioaddr->device_addr);
+
+	if (tf->flags & ATA_TFLAG_LBA48) {
+		iowrite8(tf->ctl | ATA_HOB, ioaddr->ctl_addr);
+		tf->hob_feature = ioread8(ioaddr->error_addr);
+		tf->hob_nsect = ioread8(ioaddr->nsect_addr);
+		tf->hob_lbal = ioread8(ioaddr->lbal_addr);
+		tf->hob_lbam = ioread8(ioaddr->lbam_addr);
+		tf->hob_lbah = ioread8(ioaddr->lbah_addr);
+		iowrite8(tf->ctl, ioaddr->ctl_addr);
+		ap->last_ctl = tf->ctl;
+	}
+}
+
+/**
+ *	ns87560_bmdma_status
+ *	@ap: channel to check
+ *
+ *	Return the DMA status of the channel working around the
+ *	87560 flaws.
+ */
+
+static u8 ns87560_bmdma_status(struct ata_port *ap)
+{
+	return ns87560_read_buggy(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
+}
+
+static const struct ata_port_operations ns87560_pata_ops = {
+	.set_piomode		= ns87415_set_piomode,
+	.mode_filter		= ata_pci_default_filter,
+
+	.tf_load		= ata_tf_load,
+	.tf_read		= ns87560_tf_read,
+	.check_status		= ns87560_check_status,
+	.check_atapi_dma	= ns87415_check_atapi_dma,
+	.exec_command		= ata_exec_command,
+	.dev_select		= ata_std_dev_select,
+
+	.freeze			= ata_bmdma_freeze,
+	.thaw			= ata_bmdma_thaw,
+	.error_handler		= ata_bmdma_error_handler,
+	.post_internal_cmd 	= ata_bmdma_post_internal_cmd,
+	.cable_detect		= ata_cable_40wire,
+
+	.bmdma_setup		= ns87415_bmdma_setup,
+	.bmdma_start		= ns87415_bmdma_start,
+	.bmdma_stop		= ns87415_bmdma_stop,
+	.bmdma_status		= ns87560_bmdma_status,
+	.qc_prep		= ata_qc_prep,
+	.qc_issue		= ata_qc_issue_prot,
+	.data_xfer		= ata_data_xfer,
+
+	.irq_handler		= ata_interrupt,
+	.irq_clear		= ns87415_bmdma_irq_clear,
+	.irq_on			= ata_irq_on,
+
+	.port_start		= ata_sff_port_start,
+};
+
+#endif		/* 87560 SuperIO Support */
+
+
+static const struct ata_port_operations ns87415_pata_ops = {
+	.set_piomode		= ns87415_set_piomode,
+	.mode_filter		= ata_pci_default_filter,
+
+	.tf_load		= ata_tf_load,
+	.tf_read		= ata_tf_read,
+	.check_status		= ata_check_status,
+	.check_atapi_dma	= ns87415_check_atapi_dma,
+	.exec_command		= ata_exec_command,
+	.dev_select		= ata_std_dev_select,
+
+	.freeze			= ata_bmdma_freeze,
+	.thaw			= ata_bmdma_thaw,
+	.error_handler		= ata_bmdma_error_handler,
+	.post_internal_cmd 	= ata_bmdma_post_internal_cmd,
+	.cable_detect		= ata_cable_40wire,
+
+	.bmdma_setup		= ns87415_bmdma_setup,
+	.bmdma_start		= ns87415_bmdma_start,
+	.bmdma_stop		= ns87415_bmdma_stop,
+	.bmdma_status		= ata_bmdma_status,
+	.qc_prep		= ata_qc_prep,
+	.qc_issue		= ata_qc_issue_prot,
+	.data_xfer		= ata_data_xfer,
+
+	.irq_handler		= ata_interrupt,
+	.irq_clear		= ns87415_bmdma_irq_clear,
+	.irq_on			= ata_irq_on,
+
+	.port_start		= ata_sff_port_start,
+};
+
+static struct scsi_host_template ns87415_sht = {
+	.module			= THIS_MODULE,
+	.name			= DRV_NAME,
+	.ioctl			= ata_scsi_ioctl,
+	.queuecommand		= ata_scsi_queuecmd,
+	.can_queue		= ATA_DEF_QUEUE,
+	.this_id		= ATA_SHT_THIS_ID,
+	.sg_tablesize		= LIBATA_MAX_PRD,
+	.cmd_per_lun		= ATA_SHT_CMD_PER_LUN,
+	.emulated		= ATA_SHT_EMULATED,
+	.use_clustering		= ATA_SHT_USE_CLUSTERING,
+	.proc_name		= DRV_NAME,
+	.dma_boundary		= ATA_DMA_BOUNDARY,
+	.slave_configure	= ata_scsi_slave_config,
+	.slave_destroy		= ata_scsi_slave_destroy,
+	.bios_param		= ata_std_bios_param,
+};
+
+
+/**
+ *	ns87415_init_one - Register 87415 ATA PCI device with kernel services
+ *	@pdev: PCI device to register
+ *	@ent: Entry in ns87415_pci_tbl matching with @pdev
+ *
+ *	Called from kernel PCI layer.  We probe for combined mode (sigh),
+ *	and then hand over control to libata, for it to do the rest.
+ *
+ *	LOCKING:
+ *	Inherited from PCI layer (may sleep).
+ *
+ *	RETURNS:
+ *	Zero on success, or -ERRNO value.
+ */
+
+static int ns87415_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	static int printed_version;
+	static const struct ata_port_info info = {
+		.sht		= &ns87415_sht,
+		.flags		= ATA_FLAG_SLAVE_POSS,
+		.pio_mask	= 0x1f,	/* pio0-4 */
+		.mwdma_mask	= 0x07, /* mwdma0-2 */
+		.port_ops	= &ns87415_pata_ops,
+	};
+	const struct ata_port_info *ppi[] = { &info, NULL };
+#if defined(CONFIG_SUPERIO)
+	static const struct ata_port_info info87560 = {
+		.sht		= &ns87415_sht,
+		.flags		= ATA_FLAG_SLAVE_POSS,
+		.pio_mask	= 0x1f,	/* pio0-4 */
+		.mwdma_mask	= 0x07, /* mwdma0-2 */
+		.port_ops	= &ns87560_pata_ops,
+	};
+
+	if (PCI_SLOT(pdev->devfn) == 0x0E)
+		ppi[0] = &info87560;
+#endif
+	if (!printed_version++)
+		dev_printk(KERN_DEBUG, &pdev->dev,
+			   "version " DRV_VERSION "\n");
+	/* Select 512 byte sectors */
+	pci_write_config_byte(pdev, 0x55, 0xEE);
+	/* Select PIO0 8bit clocking */
+	pci_write_config_byte(pdev, 0x54, 0xB7);
+	return ata_pci_init_one(pdev, ppi);
+}
+
+static const struct pci_device_id ns87415_pci_tbl[] = {
+	{ PCI_VDEVICE(NS, PCI_DEVICE_ID_NS_87415), },
+
+	{ }	/* terminate list */
+};
+
+static struct pci_driver ns87415_pci_driver = {
+	.name			= DRV_NAME,
+	.id_table		= ns87415_pci_tbl,
+	.probe			= ns87415_init_one,
+	.remove			= ata_pci_remove_one,
+#ifdef CONFIG_PM
+	.suspend		= ata_pci_device_suspend,
+	.resume			= ata_pci_device_resume,
+#endif
+};
+
+static int __init ns87415_init(void)
+{
+	return pci_register_driver(&ns87415_pci_driver);
+}
+
+static void __exit ns87415_exit(void)
+{
+	pci_unregister_driver(&ns87415_pci_driver);
+}
+
+module_init(ns87415_init);
+module_exit(ns87415_exit);
+
+MODULE_AUTHOR("Alan Cox");
+MODULE_DESCRIPTION("ATA low-level driver for NS87415 controllers");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(pci, ns87415_pci_tbl);
+MODULE_VERSION(DRV_VERSION);