libata: Add Intel SCH PATA driver

This patch adds Intel SCH chipsets (AF82US15W, AF82US15L, AF82UL11L)
PATA controller support.

Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/Kconfig

@@ -697,6 +697,15 @@ config PATA_SCC
 
 	  If unsure, say N.
 
+config PATA_SCH
+	tristate "Intel SCH PATA support"
+	depends on PCI
+	help
+	  This option enables support for Intel SCH PATA on the Intel
+	  SCH (US15W, US15L, UL11L) series host controllers.
+
+	  If unsure, say N.
+
 config PATA_BF54X
 	tristate "Blackfin 54x ATAPI support"
 	depends on BF542 || BF548 || BF549

drivers/ata/Makefile

@@ -67,6 +67,7 @@ obj-$(CONFIG_PATA_SIS)		+= pata_sis.o
 obj-$(CONFIG_PATA_TRIFLEX)	+= pata_triflex.o
 obj-$(CONFIG_PATA_IXP4XX_CF)	+= pata_ixp4xx_cf.o
 obj-$(CONFIG_PATA_SCC)		+= pata_scc.o
+obj-$(CONFIG_PATA_SCH)		+= pata_sch.o
 obj-$(CONFIG_PATA_BF54X)	+= pata_bf54x.o
 obj-$(CONFIG_PATA_PLATFORM)	+= pata_platform.o
 obj-$(CONFIG_PATA_OF_PLATFORM)	+= pata_of_platform.o

drivers/ata/pata_sch.c

@@ -0,0 +1,206 @@
+/*
+ *  pata_sch.c - Intel SCH PATA controllers
+ *
+ *  Copyright (c) 2008 Alek Du <alek.du@intel.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; see the file COPYING.  If not, write to
+ *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+/*
+ *  Supports:
+ *    Intel SCH (AF82US15W, AF82US15L, AF82UL11L) chipsets -- see spec at:
+ *    http://download.intel.com/design/chipsets/embedded/datashts/319537.pdf
+ */
+
+#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/dmi.h>
+
+#define DRV_NAME	"pata_sch"
+#define DRV_VERSION	"0.2"
+
+/* see SCH datasheet page 351 */
+enum {
+	D0TIM	= 0x80,		/* Device 0 Timing Register */
+	D1TIM	= 0x84,		/* Device 1 Timing Register */
+	PM	= 0x07,		/* PIO Mode Bit Mask */
+	MDM	= (0x03 << 8),	/* Multi-word DMA Mode Bit Mask */
+	UDM	= (0x07 << 16), /* Ultra DMA Mode Bit Mask */
+	PPE	= (1 << 30),	/* Prefetch/Post Enable */
+	USD	= (1 << 31),	/* Use Synchronous DMA */
+};
+
+static int sch_init_one(struct pci_dev *pdev,
+			 const struct pci_device_id *ent);
+static void sch_set_piomode(struct ata_port *ap, struct ata_device *adev);
+static void sch_set_dmamode(struct ata_port *ap, struct ata_device *adev);
+
+static const struct pci_device_id sch_pci_tbl[] = {
+	/* Intel SCH PATA Controller */
+	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_SCH_IDE), 0 },
+	{ }	/* terminate list */
+};
+
+static struct pci_driver sch_pci_driver = {
+	.name			= DRV_NAME,
+	.id_table		= sch_pci_tbl,
+	.probe			= sch_init_one,
+	.remove			= ata_pci_remove_one,
+#ifdef CONFIG_PM
+	.suspend		= ata_pci_device_suspend,
+	.resume			= ata_pci_device_resume,
+#endif
+};
+
+static struct scsi_host_template sch_sht = {
+	ATA_BMDMA_SHT(DRV_NAME),
+};
+
+static struct ata_port_operations sch_pata_ops = {
+	.inherits		= &ata_bmdma_port_ops,
+	.cable_detect		= ata_cable_unknown,
+	.set_piomode		= sch_set_piomode,
+	.set_dmamode		= sch_set_dmamode,
+};
+
+static struct ata_port_info sch_port_info = {
+	.flags		= 0,
+	.pio_mask	= ATA_PIO4,   /* pio0-4 */
+	.mwdma_mask	= ATA_MWDMA2, /* mwdma0-2 */
+	.udma_mask	= ATA_UDMA5,  /* udma0-5 */
+	.port_ops	= &sch_pata_ops,
+};
+
+MODULE_AUTHOR("Alek Du <alek.du@intel.com>");
+MODULE_DESCRIPTION("SCSI low-level driver for Intel SCH PATA controllers");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(pci, sch_pci_tbl);
+MODULE_VERSION(DRV_VERSION);
+
+/**
+ *	sch_set_piomode - Initialize host controller PATA PIO timings
+ *	@ap: Port whose timings we are configuring
+ *	@adev: ATA device
+ *
+ *	Set PIO mode for device, in host controller PCI config space.
+ *
+ *	LOCKING:
+ *	None (inherited from caller).
+ */
+
+static void sch_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+	unsigned int pio	= adev->pio_mode - XFER_PIO_0;
+	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
+	unsigned int port	= adev->devno ? D1TIM : D0TIM;
+	unsigned int data;
+
+	pci_read_config_dword(dev, port, &data);
+	/* see SCH datasheet page 351 */
+	/* set PIO mode */
+	data &= ~(PM | PPE);
+	data |= pio;
+	/* enable PPE for block device */
+	if (adev->class == ATA_DEV_ATA)
+		data |= PPE;
+	pci_write_config_dword(dev, port, data);
+}
+
+/**
+ *	sch_set_dmamode - Initialize host controller PATA DMA timings
+ *	@ap: Port whose timings we are configuring
+ *	@adev: ATA device
+ *
+ *	Set MW/UDMA mode for device, in host controller PCI config space.
+ *
+ *	LOCKING:
+ *	None (inherited from caller).
+ */
+
+static void sch_set_dmamode(struct ata_port *ap, struct ata_device *adev)
+{
+	unsigned int dma_mode	= adev->dma_mode;
+	struct pci_dev *dev	= to_pci_dev(ap->host->dev);
+	unsigned int port	= adev->devno ? D1TIM : D0TIM;
+	unsigned int data;
+
+	pci_read_config_dword(dev, port, &data);
+	/* see SCH datasheet page 351 */
+	if (dma_mode >= XFER_UDMA_0) {
+		/* enable Synchronous DMA mode */
+		data |= USD;
+		data &= ~UDM;
+		data |= (dma_mode - XFER_UDMA_0) << 16;
+	} else { /* must be MWDMA mode, since we masked SWDMA already */
+		data &= ~(USD | MDM);
+		data |= (dma_mode - XFER_MW_DMA_0) << 8;
+	}
+	pci_write_config_dword(dev, port, data);
+}
+
+/**
+ *	sch_init_one - Register SCH ATA PCI device with kernel services
+ *	@pdev: PCI device to register
+ *	@ent: Entry in sch_pci_tbl matching with @pdev
+ *
+ *	LOCKING:
+ *	Inherited from PCI layer (may sleep).
+ *
+ *	RETURNS:
+ *	Zero on success, or -ERRNO value.
+ */
+
+static int __devinit sch_init_one(struct pci_dev *pdev,
+				   const struct pci_device_id *ent)
+{
+	static int printed_version;
+	const struct ata_port_info *ppi[] = { &sch_port_info, NULL };
+	struct ata_host *host;
+	int rc;
+
+	if (!printed_version++)
+		dev_printk(KERN_DEBUG, &pdev->dev,
+			   "version " DRV_VERSION "\n");
+
+	/* enable device and prepare host */
+	rc = pcim_enable_device(pdev);
+	if (rc)
+		return rc;
+	rc = ata_pci_sff_prepare_host(pdev, ppi, &host);
+	if (rc)
+		return rc;
+	pci_set_master(pdev);
+	return ata_pci_sff_activate_host(host, ata_sff_interrupt, &sch_sht);
+}
+
+static int __init sch_init(void)
+{
+	return pci_register_driver(&sch_pci_driver);
+}
+
+static void __exit sch_exit(void)
+{
+	pci_unregister_driver(&sch_pci_driver);
+}
+
+module_init(sch_init);
+module_exit(sch_exit);