cmd64x: fix multiword and remove single-word DMA support

Fix the multiword DMA and drop the single-word DMA support (which nobody will
miss, I think).  In order to do it, a number of changes was necessary:

- rename program_drive_counts() to program_cycle_times(), pass to it cycle's
  total/active times instead of the clock counts, and convert them into the
  active/recovery clocks there instead of cmd64x_tune_pio() -- this causes
  quantize_timing() to also move;

- contrarywise, move all the code handling the address setup timing into
  cmd64x_tune_pio(), so that setting MWDMA mode wouldn't change address setup;

- remove from the speedproc() method the  bogus code pretending to set the DMA
  timings by twiddling bits in the BMIDE status register, handle setting MWDMA
  by just calling program_cycle_times(); while at it, improve the style of that
  whole switch statement;

- stop fiddling with the DMA capable bits in the speedproc() method -- they do
  not enable DMA, and are properly dealt with by the dma_host_{on,off} methods;

- don't set hwif->swdma_mask in the init_hwif() method anymore.

In addition to those changes, do the following:

- in cmd64x_tune_pio(), when writing to ARTTIM23 register preserve the interrupt
  status bit, eliminate local_irq_{save|restore}() around this code as there's
  *no* actual race with the interrupt handler, and move cmdprintk() to a more
  fitting place -- after ide_get_best_pio_mode() call;

- make {arttim|drwtim}_regs arrays single-dimensional, indexed with drive->dn;

- rename {setup|recovery}_counts[] into more fitting {setup|recovery}_values[];

- in  the speedproc() method, get rid of the duplicate reads/writes from/to the
  UDIDETCRx registers and of the extra variable used to store the transfer mode
  value after filtering,  use another method of determining master/slave drive,
  and cleanup useless parens;

- beautify cmdprintk() output here and there.

While at it, remove meaningless comment about the driver being used only on
UltraSPARC and long non-relevant RCS tag. :-)

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 117 insertions, 131 deletions

diff --git a/drivers/ide/pci/cmd64x.c b/drivers/ide/pci/cmd64x.c
index 561197f7b5bb..336d02f58010 100644
--- a/drivers/ide/pci/cmd64x.c
+++ b/drivers/ide/pci/cmd64x.c
@@ -1,10 +1,7 @@
-/* $Id: cmd64x.c,v 1.21 2000/01/30 23:23:16
- *
- * linux/drivers/ide/pci/cmd64x.c               Version 1.42    Feb 8, 2007
+/*
+ * linux/drivers/ide/pci/cmd64x.c               Version 1.43    Mar 10, 2007
  *
  * cmd64x.c: Enable interrupts at initialization time on Ultra/PCI machines.
- *           Note, this driver is not used at all on other systems because
- *           there the "BIOS" has done all of the following already.
  *           Due to massive hardware bugs, UltraDMA is only supported
  *           on the 646U2 and not on the 646U.
  *
@@ -195,116 +192,103 @@ static u8 quantize_timing(int timing, int quant)
 }
 
 /*
- * This routine writes the prepared setup/active/recovery counts
- * for a drive into the cmd646 chipset registers to active them.
+ * This routine calculates active/recovery counts and then writes them into
+ * the chipset registers.
  */
-static void program_drive_counts (ide_drive_t *drive, int setup_count, int active_count, int recovery_count)
+static void program_cycle_times (ide_drive_t *drive, int cycle_time, int active_time)
 {
-        unsigned long flags;
-        struct pci_dev *dev = HWIF(drive)->pci_dev;
-        ide_drive_t *drives = HWIF(drive)->drives;
-        u8 temp_b;
-        static const u8 setup_counts[] = {0x40, 0x40, 0x40, 0x80, 0, 0xc0};
-        static const u8 recovery_counts[] =
+        struct pci_dev *dev     = HWIF(drive)->pci_dev;
+        int clock_time          = 1000 / system_bus_clock();
+        u8  cycle_count, active_count, recovery_count, drwtim;
+        static const u8 recovery_values[] =
                 {15, 15, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 0};
-        static const u8 arttim_regs[2][2] = {
-                        { ARTTIM0, ARTTIM1 },
-                        { ARTTIM23, ARTTIM23 }
-                };
-        static const u8 drwtim_regs[2][2] = {
-                        { DRWTIM0, DRWTIM1 },
-                        { DRWTIM2, DRWTIM3 }
-                };
-        int channel = (int) HWIF(drive)->channel;
-        int slave = (drives != drive);  /* Is this really the best way to determine this?? */
-
-        cmdprintk("program_drive_count parameters = s(%d),a(%d),r(%d),p(%d)\n",
-                setup_count, active_count, recovery_count, drive->present);
+        static const u8 drwtim_regs[4] = {DRWTIM0, DRWTIM1, DRWTIM2, DRWTIM3};
+
+        cmdprintk("program_cycle_times parameters: total=%d, active=%d\n",
+                  cycle_time, active_time);
+
+        cycle_count     = quantize_timing( cycle_time, clock_time);
+        active_count    = quantize_timing(active_time, clock_time);
+        recovery_count  = cycle_count - active_count;
+
         /*
-         * Set up address setup count registers.
-         * Primary interface has individual count/timing registers for
-         * each drive.  Secondary interface has one common set of registers,
-         * for address setup so we merge these timings, using the slowest
-         * value.
+         * In case we've got too long recovery phase, try to lengthen
+         * the active phase
          */
-        if (channel) {
-                drive->drive_data = setup_count;
-                setup_count = max(drives[0].drive_data,
-                                        drives[1].drive_data);
-                cmdprintk("Secondary interface, setup_count = %d\n",
-                                        setup_count);
+        if (recovery_count > 16) {
+                active_count += recovery_count - 16;
+                recovery_count = 16;
         }
+        if (active_count > 16)          /* shouldn't actually happen... */
+                active_count = 16;
+
+        cmdprintk("Final counts: total=%d, active=%d, recovery=%d\n",
+                  cycle_count, active_count, recovery_count);
 
         /*
          * Convert values to internal chipset representation
          */
-        setup_count = (setup_count > 5) ? 0xc0 : (int) setup_counts[setup_count];
-        active_count &= 0xf; /* Remember, max value is 16 */
-        recovery_count = (int) recovery_counts[recovery_count];
-
-        cmdprintk("Final values = %d,%d,%d\n",
-                setup_count, active_count, recovery_count);
+        recovery_count = recovery_values[recovery_count];
+        active_count  &= 0x0f;
 
-        /*
-         * Now that everything is ready, program the new timings
-         */
-        local_irq_save(flags);
-        /*
-         * Program the address_setup clocks into ARTTIM reg,
-         * and then the active/recovery counts into the DRWTIM reg
-         */
-        (void) pci_read_config_byte(dev, arttim_regs[channel][slave], &temp_b);
-        (void) pci_write_config_byte(dev, arttim_regs[channel][slave],
-                ((u8) setup_count) | (temp_b & 0x3f));
-        (void) pci_write_config_byte(dev, drwtim_regs[channel][slave],
-                (u8) ((active_count << 4) | recovery_count));
-        cmdprintk ("Write %x to %x\n",
-                ((u8) setup_count) | (temp_b & 0x3f),
-                arttim_regs[channel][slave]);
-        cmdprintk ("Write %x to %x\n",
-                (u8) ((active_count << 4) | recovery_count),
-                drwtim_regs[channel][slave]);
-        local_irq_restore(flags);
+        /* Program the active/recovery counts into the DRWTIM register */
+        drwtim = (active_count << 4) | recovery_count;
+        (void) pci_write_config_byte(dev, drwtim_regs[drive->dn], drwtim);
+        cmdprintk("Write 0x%02x to reg 0x%x\n", drwtim, drwtim_regs[drive->dn]);
 }
 
 /*
- * This routine selects drive's best PIO mode, calculates setup/active/recovery
- * counts, and then writes them into the chipset registers.
+ * This routine selects drive's best PIO mode and writes into the chipset
+ * registers setup/active/recovery timings.
  */
 static u8 cmd64x_tune_pio (ide_drive_t *drive, u8 mode_wanted)
 {
-        int setup_time, active_time, cycle_time;
-        u8  cycle_count, setup_count, active_count, recovery_count;
-        u8  pio_mode;
-        int clock_time = 1000 / system_bus_clock();
+        ide_hwif_t *hwif        = HWIF(drive);
+        struct pci_dev *dev     = hwif->pci_dev;
         ide_pio_data_t pio;
-
+        u8 pio_mode, setup_count, arttim = 0;
+        static const u8 setup_values[] = {0x40, 0x40, 0x40, 0x80, 0, 0xc0};
+        static const u8 arttim_regs[4] = {ARTTIM0, ARTTIM1, ARTTIM23, ARTTIM23};
         pio_mode = ide_get_best_pio_mode(drive, mode_wanted, 5, &pio);
-        cycle_time = pio.cycle_time;
 
-        setup_time  = ide_pio_timings[pio_mode].setup_time;
-        active_time = ide_pio_timings[pio_mode].active_time;
+        cmdprintk("%s: PIO mode wanted %d, selected %d (%d ns)%s\n",
+                  drive->name, mode_wanted, pio_mode, pio.cycle_time,
+                  pio.overridden ? " (overriding vendor mode)" : "");
 
-        setup_count  = quantize_timing( setup_time, clock_time);
-        cycle_count  = quantize_timing( cycle_time, clock_time);
-        active_count = quantize_timing(active_time, clock_time);
+        program_cycle_times(drive, pio.cycle_time,
+                            ide_pio_timings[pio_mode].active_time);
 
-        recovery_count = cycle_count - active_count;
-        /* program_drive_counts() takes care of zero recovery cycles */
-        if (recovery_count > 16) {
-                active_count += recovery_count - 16;
-                recovery_count = 16;
+        setup_count = quantize_timing(ide_pio_timings[pio_mode].setup_time,
+                                      1000 / system_bus_clock());
+
+        /*
+         * The primary channel has individual address setup timing registers
+         * for each drive and the hardware selects the slowest timing itself.
+         * The secondary channel has one common register and we have to select
+         * the slowest address setup timing ourselves.
+         */
+        if (hwif->channel) {
+                ide_drive_t *drives = hwif->drives;
+
+                drive->drive_data = setup_count;
+                setup_count = max(drives[0].drive_data, drives[1].drive_data);
         }
-        if (active_count > 16)
-                active_count = 16; /* maximum allowed by cmd64x */
 
-        program_drive_counts (drive, setup_count, active_count, recovery_count);
+        if (setup_count > 5)            /* shouldn't actually happen... */
+                setup_count = 5;
+        cmdprintk("Final address setup count: %d\n", setup_count);
 
-        cmdprintk("%s: PIO mode wanted %d, selected %d (%dns)%s, "
-                "clocks=%d/%d/%d\n",
-                drive->name, mode_wanted, pio_mode, cycle_time,
-                pio.overridden ? " (overriding vendor mode)" : "",
-                setup_count, active_count, recovery_count);
+        /*
+         * Program the address setup clocks into the ARTTIM registers.
+         * Avoid clearing the secondary channel's interrupt bit.
+         */
+        (void) pci_read_config_byte (dev, arttim_regs[drive->dn], &arttim);
+        if (hwif->channel)
+                arttim &= ~ARTTIM23_INTR_CH1;
+        arttim &= ~0xc0;
+        arttim |= setup_values[setup_count];
+        (void) pci_write_config_byte(dev, arttim_regs[drive->dn], arttim);
+        cmdprintk("Write 0x%02x to reg 0x%x\n", arttim, arttim_regs[drive->dn]);
 
         return pio_mode;
 }
@@ -376,61 +360,64 @@ static u8 cmd64x_ratemask (ide_drive_t *drive)
         return mode;
 }
 
-static int cmd64x_tune_chipset (ide_drive_t *drive, u8 xferspeed)
+static int cmd64x_tune_chipset (ide_drive_t *drive, u8 speed)
 {
         ide_hwif_t *hwif        = HWIF(drive);
         struct pci_dev *dev     = hwif->pci_dev;
+        u8 unit                 = drive->dn & 0x01;
+        u8 regU = 0, pciU       = hwif->channel ? UDIDETCR1 : UDIDETCR0;
 
-        u8 unit                 = (drive->select.b.unit & 0x01);
-        u8 regU = 0, pciU       = (hwif->channel) ? UDIDETCR1 : UDIDETCR0;
-        u8 regD = 0, pciD       = (hwif->channel) ? BMIDESR1 : BMIDESR0;
-
-        u8 speed        = ide_rate_filter(cmd64x_ratemask(drive), xferspeed);
+        speed = ide_rate_filter(cmd64x_ratemask(drive), speed);
 
         if (speed >= XFER_SW_DMA_0) {
-                (void) pci_read_config_byte(dev, pciD, &regD);
                 (void) pci_read_config_byte(dev, pciU, &regU);
-                regD &= ~(unit ? 0x40 : 0x20);
                 regU &= ~(unit ? 0xCA : 0x35);
-                (void) pci_write_config_byte(dev, pciD, regD);
-                (void) pci_write_config_byte(dev, pciU, regU);
-                (void) pci_read_config_byte(dev, pciD, &regD);
-                (void) pci_read_config_byte(dev, pciU, &regU);
         }
 
         switch(speed) {
-                case XFER_UDMA_5:       regU |= (unit ? 0x0A : 0x05); break;
-                case XFER_UDMA_4:       regU |= (unit ? 0x4A : 0x15); break;
-                case XFER_UDMA_3:       regU |= (unit ? 0x8A : 0x25); break;
-                case XFER_UDMA_2:       regU |= (unit ? 0x42 : 0x11); break;
-                case XFER_UDMA_1:       regU |= (unit ? 0x82 : 0x21); break;
-                case XFER_UDMA_0:       regU |= (unit ? 0xC2 : 0x31); break;
-                case XFER_MW_DMA_2:     regD |= (unit ? 0x40 : 0x10); break;
-                case XFER_MW_DMA_1:     regD |= (unit ? 0x80 : 0x20); break;
-                case XFER_MW_DMA_0:     regD |= (unit ? 0xC0 : 0x30); break;
-                case XFER_SW_DMA_2:     regD |= (unit ? 0x40 : 0x10); break;
-                case XFER_SW_DMA_1:     regD |= (unit ? 0x80 : 0x20); break;
-                case XFER_SW_DMA_0:     regD |= (unit ? 0xC0 : 0x30); break;
-                case XFER_PIO_5:
-                case XFER_PIO_4:
-                case XFER_PIO_3:
-                case XFER_PIO_2:
-                case XFER_PIO_1:
-                case XFER_PIO_0:
-                        (void) cmd64x_tune_pio(drive, speed - XFER_PIO_0);
-                        break;
-
-                default:
-                        return 1;
+        case XFER_UDMA_5:
+                regU |= unit ? 0x0A : 0x05;
+                break;
+        case XFER_UDMA_4:
+                regU |= unit ? 0x4A : 0x15;
+                break;
+        case XFER_UDMA_3:
+                regU |= unit ? 0x8A : 0x25;
+                break;
+        case XFER_UDMA_2:
+                regU |= unit ? 0x42 : 0x11;
+                break;
+        case XFER_UDMA_1:
+                regU |= unit ? 0x82 : 0x21;
+                break;
+        case XFER_UDMA_0:
+                regU |= unit ? 0xC2 : 0x31;
+                break;
+        case XFER_MW_DMA_2:
+                program_cycle_times(drive, 120, 70);
+                break;
+        case XFER_MW_DMA_1:
+                program_cycle_times(drive, 150, 80);
+                break;
+        case XFER_MW_DMA_0:
+                program_cycle_times(drive, 480, 215);
+                break;
+        case XFER_PIO_5:
+        case XFER_PIO_4:
+        case XFER_PIO_3:
+        case XFER_PIO_2:
+        case XFER_PIO_1:
+        case XFER_PIO_0:
+                (void) cmd64x_tune_pio(drive, speed - XFER_PIO_0);
+                break;
+        default:
+                return 1;
         }
 
-        if (speed >= XFER_SW_DMA_0) {
+        if (speed >= XFER_SW_DMA_0)
                 (void) pci_write_config_byte(dev, pciU, regU);
-                regD |= (unit ? 0x40 : 0x20);
-                (void) pci_write_config_byte(dev, pciD, regD);
-        }
 
-        return (ide_config_drive_speed(drive, speed));
+        return ide_config_drive_speed(drive, speed);
 }
 
 static int config_chipset_for_dma (ide_drive_t *drive)
@@ -665,7 +652,6 @@ static void __devinit init_hwif_cmd64x(ide_hwif_t *hwif)
 
         hwif->ultra_mask = 0x3f;
         hwif->mwdma_mask = 0x07;
-        hwif->swdma_mask = 0x07;
 
         if (dev->device == PCI_DEVICE_ID_CMD_643)
                 hwif->ultra_mask = 0x80;