sata_promise: ATAPI support

This patch adds ATAPI support to the sata_promise driver.
This has been tested on both first- and second-generation
chips (20378 and 20575), and with both SATAPI and PATAPI
devices. CD-writing works.

SATAPI DMA works on second-generation chips, but on
first-generation chips SATAPI is limited to PIO due
to what appears to be HW limitations.
PATAPI DMA works on both first- and second-generation
chips, but requires the separate PATA support patch
before it can be used on TX2plus chips.

The functional changes to the driver are:
- remove ATA_FLAG_NO_ATAPI from PDC_COMMON_FLAGS
- add ->check_atapi_dma() operation to enable DMA for bulk data
  transfers but force PIO for other ATAPI commands; this filter
  is from Promise's driver and largely matches pata_pdc207x.c
- use a more restrictive ->check_atapi_dma() on first-generation
  chips to force SATAPI to always use PIO
- add handling of ATAPI protocols to pdc_qc_prep(), pdc_host_intr(),
  and pdc_qc_issue_prot(): ATAPI_DMA is handled by the driver
  while non-DMA protocols are handed over to libata generic code
- add pdc_issue_atapi_pkt_cmd() to handle the initial steps in
  issuing ATAPI DMA commands before sending the actual CDB;
  this procedure was ported from Promise's driver

Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 215 insertions, 7 deletions

diff --git a/drivers/ata/sata_promise.c b/drivers/ata/sata_promise.c
index 6ab057417386..9bd195fbd884 100644
--- a/drivers/ata/sata_promise.c
+++ b/drivers/ata/sata_promise.c
@@ -39,6 +39,7 @@
 #include <linux/interrupt.h>
 #include <linux/sched.h>
 #include <linux/device.h>
+#include <scsi/scsi.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_cmnd.h>
 #include <linux/libata.h>
@@ -50,6 +51,14 @@
 
 
 enum {
+        /* register offsets */
+        PDC_FEATURE             = 0x04, /* Feature/Error reg (per port) */
+        PDC_SECTOR_COUNT        = 0x08, /* Sector count reg (per port) */
+        PDC_SECTOR_NUMBER       = 0x0C, /* Sector number reg (per port) */
+        PDC_CYLINDER_LOW        = 0x10, /* Cylinder low reg (per port) */
+        PDC_CYLINDER_HIGH       = 0x14, /* Cylinder high reg (per port) */
+        PDC_DEVICE              = 0x18, /* Device/Head reg (per port) */
+        PDC_COMMAND             = 0x1C, /* Command/status reg (per port) */
         PDC_PKT_SUBMIT          = 0x40, /* Command packet pointer addr */
         PDC_INT_SEQMASK         = 0x40, /* Mask of asserted SEQ INTs */
         PDC_FLASH_CTL           = 0x44, /* Flash control register */
@@ -71,13 +80,23 @@ enum {
 
         PDC_HAS_PATA            = (1 << 1), /* PDC20375/20575 has PATA */
 
+        /* Sequence counter control registers bit definitions */
+        PDC_SEQCNTRL_INT_MASK   = (1 << 5), /* Sequence Interrupt Mask */
+
+        /* Feature register values */
+        PDC_FEATURE_ATAPI_PIO   = 0x00, /* ATAPI data xfer by PIO */
+        PDC_FEATURE_ATAPI_DMA   = 0x01, /* ATAPI data xfer by DMA */
+
+        /* Device/Head register values */
+        PDC_DEVICE_SATA         = 0xE0, /* Device/Head value for SATA devices */
+
         /* PDC_CTLSTAT bit definitions */
         PDC_DMA_ENABLE          = (1 << 7),
         PDC_IRQ_DISABLE         = (1 << 10),
         PDC_RESET               = (1 << 11), /* HDMA reset */
 
         PDC_COMMON_FLAGS        = ATA_FLAG_NO_LEGACY |
-                                  ATA_FLAG_MMIO | ATA_FLAG_NO_ATAPI |
+                                  ATA_FLAG_MMIO |
                                   ATA_FLAG_PIO_POLLING,
 
         /* hp->flags bits */
@@ -106,6 +125,8 @@ static void pdc_pata_phy_reset(struct ata_port *ap);
 static void pdc_qc_prep(struct ata_queued_cmd *qc);
 static void pdc_tf_load_mmio(struct ata_port *ap, const struct ata_taskfile *tf);
 static void pdc_exec_command_mmio(struct ata_port *ap, const struct ata_taskfile *tf);
+static int pdc_check_atapi_dma(struct ata_queued_cmd *qc);
+static int pdc_old_check_atapi_dma(struct ata_queued_cmd *qc);
 static void pdc_irq_clear(struct ata_port *ap);
 static unsigned int pdc_qc_issue_prot(struct ata_queued_cmd *qc);
 static void pdc_host_stop(struct ata_host *host);
@@ -140,6 +161,34 @@ static const struct ata_port_operations pdc_sata_ops = {
         .check_status           = ata_check_status,
         .exec_command           = pdc_exec_command_mmio,
         .dev_select             = ata_std_dev_select,
+        .check_atapi_dma        = pdc_check_atapi_dma,
+
+        .qc_prep                = pdc_qc_prep,
+        .qc_issue               = pdc_qc_issue_prot,
+        .freeze                 = pdc_freeze,
+        .thaw                   = pdc_thaw,
+        .error_handler          = pdc_error_handler,
+        .post_internal_cmd      = pdc_post_internal_cmd,
+        .data_xfer              = ata_mmio_data_xfer,
+        .irq_handler            = pdc_interrupt,
+        .irq_clear              = pdc_irq_clear,
+
+        .scr_read               = pdc_sata_scr_read,
+        .scr_write              = pdc_sata_scr_write,
+        .port_start             = pdc_port_start,
+        .port_stop              = pdc_port_stop,
+        .host_stop              = pdc_host_stop,
+};
+
+/* First-generation chips need a more restrictive ->check_atapi_dma op */
+static const struct ata_port_operations pdc_old_sata_ops = {
+        .port_disable           = ata_port_disable,
+        .tf_load                = pdc_tf_load_mmio,
+        .tf_read                = ata_tf_read,
+        .check_status           = ata_check_status,
+        .exec_command           = pdc_exec_command_mmio,
+        .dev_select             = ata_std_dev_select,
+        .check_atapi_dma        = pdc_old_check_atapi_dma,
 
         .qc_prep                = pdc_qc_prep,
         .qc_issue               = pdc_qc_issue_prot,
@@ -165,6 +214,7 @@ static const struct ata_port_operations pdc_pata_ops = {
         .check_status           = ata_check_status,
         .exec_command           = pdc_exec_command_mmio,
         .dev_select             = ata_std_dev_select,
+        .check_atapi_dma        = pdc_check_atapi_dma,
 
         .phy_reset              = pdc_pata_phy_reset,
 
@@ -188,7 +238,7 @@ static const struct ata_port_info pdc_port_info[] = {
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .mwdma_mask     = 0x07, /* mwdma0-2 */
                 .udma_mask      = 0x7f, /* udma0-6 ; FIXME */
-                .port_ops       = &pdc_sata_ops,
+                .port_ops       = &pdc_old_sata_ops,
         },
 
         /* board_20319 */
@@ -198,7 +248,7 @@ static const struct ata_port_info pdc_port_info[] = {
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .mwdma_mask     = 0x07, /* mwdma0-2 */
                 .udma_mask      = 0x7f, /* udma0-6 ; FIXME */
-                .port_ops       = &pdc_sata_ops,
+                .port_ops       = &pdc_old_sata_ops,
         },
 
         /* board_20619 */
@@ -397,6 +447,30 @@ static void pdc_sata_scr_write (struct ata_port *ap, unsigned int sc_reg,
         writel(val, (void __iomem *) ap->ioaddr.scr_addr + (sc_reg * 4));
 }
 
+static void pdc_atapi_dma_pkt(struct ata_taskfile *tf,
+                              dma_addr_t sg_table,
+                              unsigned int cdb_len, u8 *cdb,
+                              u8 *buf)
+{
+        u32 *buf32 = (u32 *) buf;
+
+        /* set control bits (byte 0), zero delay seq id (byte 3),
+         * and seq id (byte 2)
+         */
+        if (!(tf->flags & ATA_TFLAG_WRITE))
+                buf32[0] = cpu_to_le32(PDC_PKT_READ);
+        else
+                buf32[0] = 0;
+        buf32[1] = cpu_to_le32(sg_table);       /* S/G table addr */
+        buf32[2] = 0;                           /* no next-packet */
+
+        /* we can represent cdb lengths 2/4/6/8/10/12/14/16 */
+        BUG_ON(cdb_len & ~0x1E);
+
+        buf[12] = (((cdb_len >> 1) & 7) << 5) | ATA_REG_DATA | PDC_LAST_REG;
+        memcpy(buf+13, cdb, cdb_len);
+}
+
 static void pdc_qc_prep(struct ata_queued_cmd *qc)
 {
         struct pdc_port_priv *pp = qc->ap->private_data;
@@ -421,6 +495,16 @@ static void pdc_qc_prep(struct ata_queued_cmd *qc)
                 pdc_pkt_footer(&qc->tf, pp->pkt, i);
                 break;
 
+        case ATA_PROT_ATAPI:
+        case ATA_PROT_ATAPI_NODATA:
+                ata_qc_prep(qc);
+                break;
+
+        case ATA_PROT_ATAPI_DMA:
+                ata_qc_prep(qc);
+                pdc_atapi_dma_pkt(&qc->tf, qc->ap->prd_dma, qc->dev->cdb_len, qc->cdb, pp->pkt);
+                break;
+
         default:
                 break;
         }
@@ -534,6 +618,7 @@ static inline unsigned int pdc_host_intr( struct ata_port *ap,
         switch (qc->tf.protocol) {
         case ATA_PROT_DMA:
         case ATA_PROT_NODATA:
+        case ATA_PROT_ATAPI_DMA:
                 qc->err_mask |= ac_err_mask(ata_wait_idle(ap));
                 ata_qc_complete(qc);
                 handled = 1;
@@ -630,18 +715,105 @@ static inline void pdc_packet_start(struct ata_queued_cmd *qc)
         readl((void __iomem *) ap->ioaddr.cmd_addr + PDC_PKT_SUBMIT); /* flush */
 }
 
+static unsigned int pdc_wait_for_drq(struct ata_port *ap)
+{ 
+        void __iomem *port_mmio = (void __iomem *) ap->ioaddr.cmd_addr;
+        unsigned int i;
+        unsigned int status;
+
+        /* Following pdc-ultra's WaitForDrq() we loop here until BSY
+         * is clear and DRQ is set in altstatus. We could possibly call
+         * ata_busy_wait() and loop until DRQ is set, but since we don't
+         * know how much time a call to ata_busy_wait() took, we don't
+         * know when to time out the outer loop.
+         */
+        for(i = 0; i < 1000; ++i) {
+                status = readb(port_mmio + 0x38); /* altstatus */
+                if (status == 0xFF)
+                        break;
+                if (status & ATA_BUSY)
+                        ;
+                else if (status & (ATA_DRQ | ATA_ERR))
+                        break;
+                mdelay(1);
+        }
+        if (i >= 1000)
+                ata_port_printk(ap, KERN_WARNING, "%s timed out", __FUNCTION__);
+        return status;
+}
+
+static void pdc_issue_atapi_pkt_cmd(struct ata_queued_cmd *qc)
+{
+        struct ata_port *ap = qc->ap;
+        void __iomem *port_mmio = (void __iomem *) ap->ioaddr.cmd_addr;
+        void __iomem *host_mmio = ap->host->mmio_base;
+        unsigned int nbytes;
+        unsigned int tmp;
+
+        writeb(0x00, port_mmio + PDC_CTLSTAT); /* route drive INT to SEQ 0 */
+        writeb(PDC_SEQCNTRL_INT_MASK, host_mmio + 0); /* but mask SEQ 0 INT */
+
+        /* select drive */
+        if (sata_scr_valid(ap)) {
+                tmp = PDC_DEVICE_SATA;
+        } else {
+                tmp = ATA_DEVICE_OBS;
+                if (qc->dev->devno != 0)
+                        tmp |= ATA_DEV1;
+        }
+        writeb(tmp, port_mmio + PDC_DEVICE);
+        ata_busy_wait(ap, ATA_BUSY, 1000);
+
+        writeb(0x00, port_mmio + PDC_SECTOR_COUNT);
+        writeb(0x00, port_mmio + PDC_SECTOR_NUMBER);
+
+        /* set feature and byte counter registers */
+        if (qc->tf.protocol != ATA_PROT_ATAPI_DMA) {
+                tmp = PDC_FEATURE_ATAPI_PIO;
+                /* set byte counter register to real transfer byte count */
+                nbytes = qc->nbytes;
+                if (!nbytes)
+                        nbytes = qc->nsect << 9;
+                if (nbytes > 0xffff)
+                        nbytes = 0xffff;
+        } else {
+                tmp = PDC_FEATURE_ATAPI_DMA;
+                /* set byte counter register to 0 */
+                nbytes = 0;
+        }
+        writeb(tmp, port_mmio + PDC_FEATURE);
+        writeb(nbytes & 0xFF, port_mmio + PDC_CYLINDER_LOW);
+        writeb((nbytes >> 8) & 0xFF, port_mmio + PDC_CYLINDER_HIGH);
+
+        /* send ATAPI packet command 0xA0 */
+        writeb(ATA_CMD_PACKET, port_mmio + PDC_COMMAND);
+
+        /*
+         * At this point in the issuing of a packet command, the Promise
+         * driver busy-waits for INT (CTLSTAT bit 27) if it detected
+         * (at port init time) that the device interrupts with assertion
+         * of DRQ after receiving a packet command.
+         *
+         * XXX: Do we need to handle this case as well? Does libata detect
+         * this case for us, or do we have to do our own per-port init?
+         */
+
+        pdc_wait_for_drq(ap);
+
+        /* now the device only waits for the CDB */
+}
+
 static unsigned int pdc_qc_issue_prot(struct ata_queued_cmd *qc)
 {
         switch (qc->tf.protocol) {
+        case ATA_PROT_ATAPI_DMA:
+                pdc_issue_atapi_pkt_cmd(qc);
+                /*FALLTHROUGH*/
         case ATA_PROT_DMA:
         case ATA_PROT_NODATA:
                 pdc_packet_start(qc);
                 return 0;
 
-        case ATA_PROT_ATAPI_DMA:
-                BUG();
-                break;
-
         default:
                 break;
         }
@@ -664,6 +836,42 @@ static void pdc_exec_command_mmio(struct ata_port *ap, const struct ata_taskfile
         ata_exec_command(ap, tf);
 }
 
+static int pdc_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+        u8 *scsicmd = qc->scsicmd->cmnd;
+        int pio = 1; /* atapi dma off by default */
+
+        /* Whitelist commands that may use DMA. */
+        switch (scsicmd[0]) {
+        case WRITE_12:
+        case WRITE_10:
+        case WRITE_6:
+        case READ_12:
+        case READ_10:
+        case READ_6:
+        case 0xad: /* READ_DVD_STRUCTURE */
+        case 0xbe: /* READ_CD */
+                pio = 0;
+        }
+        /* -45150 (FFFF4FA2) to -1 (FFFFFFFF) shall use PIO mode */
+        if (scsicmd[0] == WRITE_10) {
+                unsigned int lba;
+                lba = (scsicmd[2] << 24) | (scsicmd[3] << 16) | (scsicmd[4] << 8) | scsicmd[5];
+                if (lba >= 0xFFFF4FA2)
+                        pio = 1;
+        }
+        return pio;
+}
+
+static int pdc_old_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+        struct ata_port *ap = qc->ap;
+
+        /* First generation chips cannot use ATAPI DMA on SATA ports */
+        if (sata_scr_valid(ap))
+                return 1;
+        return pdc_check_atapi_dma(qc);
+}
 
 static void pdc_ata_setup_port(struct ata_ioports *port, unsigned long base)
 {