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>

3 files changed, 477 insertions, 0 deletions

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 3a737bdce2e..cf960bd1c00 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -441,6 +441,15 @@ config PATA_NS87410
 
           If unsure, say N.
 
+config PATA_NS87415
+        tristate "Nat Semi NS87415 PATA support (Experimental)"
+        depends on PCI && EXPERIMENTAL
+        help
+          This option enables support for the National Semiconductor
+          NS87415 PCI-IDE controller.
+
+          If unsure, say N.
+
 config PATA_OPTI
         tristate "OPTI621/6215 PATA support (Very Experimental)"
         depends on PCI && EXPERIMENTAL
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 4eb7fb44be3..56bf13cbd19 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_PATA_IT8213)	+= pata_it8213.o
 obj-$(CONFIG_PATA_JMICRON)      += pata_jmicron.o
 obj-$(CONFIG_PATA_NETCELL)      += pata_netcell.o
 obj-$(CONFIG_PATA_NS87410)      += pata_ns87410.o
+obj-$(CONFIG_PATA_NS87415)      += pata_ns87415.o
 obj-$(CONFIG_PATA_OPTI)         += pata_opti.o
 obj-$(CONFIG_PATA_OPTIDMA)      += pata_optidma.o
 obj-$(CONFIG_PATA_MPC52xx)      += pata_mpc52xx.o
diff --git a/drivers/ata/pata_ns87415.c b/drivers/ata/pata_ns87415.c
new file mode 100644
index 00000000000..bb97ef583f9
--- /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);