pata_sis: Implement MWDMA for the UDMA 133 capable chips

Bartlomiej pointed out that while this got fixed in the old driver whoever
did it didn't port it across.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 69 insertions, 22 deletions

diff --git a/drivers/ata/pata_sis.c b/drivers/ata/pata_sis.c
index 488e77bcd22b..d70ecece93ee 100644
--- a/drivers/ata/pata_sis.c
+++ b/drivers/ata/pata_sis.c
@@ -252,24 +252,25 @@ static void sis_100_set_piomode (struct ata_port *ap, struct ata_device *adev)
 }
 
 /**
- *      sis_133_set_piomode - Initialize host controller PATA PIO timings
+ *      sis_133_do_piomode - Initialize host controller PATA PIO/DMA timings
  *      @ap: Port whose timings we are configuring
  *      @adev: Device we are configuring for.
  *
  *      Set PIO mode for device, in host controller PCI config space. This
- *      function handles PIO set up for the later ATA133 devices.
+ *      function handles PIO set up for the later ATA133 devices. The same
+ *      timings are used for MWDMA.
  *
  *      LOCKING:
  *      None (inherited from caller).
  */
 
-static void sis_133_set_piomode (struct ata_port *ap, struct ata_device *adev)
+static void sis_133_do_piomode(struct ata_port *ap, struct ata_device *adev,
+                                        int speed)
 {
         struct pci_dev *pdev    = to_pci_dev(ap->host->dev);
         int port = 0x40;
         u32 t1;
         u32 reg54;
-        int speed = adev->pio_mode - XFER_PIO_0;
 
         const u32 timing133[] = {
                 0x28269000,     /* Recovery << 24 | Act << 16 | Ini << 12 */
@@ -305,6 +306,42 @@ static void sis_133_set_piomode (struct ata_port *ap, struct ata_device *adev)
 }
 
 /**
+ *      sis_133_set_piomode - Initialize host controller PATA PIO timings
+ *      @ap: Port whose timings we are configuring
+ *      @adev: Device we are configuring for.
+ *
+ *      Set PIO mode for device, in host controller PCI config space. This
+ *      function handles PIO set up for the later ATA133 devices.
+ *
+ *      LOCKING:
+ *      None (inherited from caller).
+ */
+
+static void sis_133_set_piomode (struct ata_port *ap, struct ata_device *adev)
+{
+
+        sis_133_do_piomode(ap, adev, adev->pio_mode - XFER_PIO_0);
+}
+
+/**
+ *      mwdma_clip_to_pio               -       clip MWDMA mode
+ *      @adev: device
+ *
+ *      As the SiS shared MWDMA and PIO timings we must program the equivalent
+ *      PIO timing for the MWDMA mode but we must not program one higher than
+ *      the permitted PIO timing of the device.
+ */
+
+static int mwdma_clip_to_pio(struct ata_device *adev)
+{
+        const int mwdma_to_pio[3] = {
+                XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
+        };
+        return min(mwdma_to_pio[adev->dma_mode - XFER_MW_DMA_0],
+                                adev->pio_mode - XFER_PIO_0);
+}
+
+/**
  *      sis_old_set_dmamode - Initialize host controller PATA DMA timings
  *      @ap: Port whose timings we are configuring
  *      @adev: Device to program
@@ -332,6 +369,7 @@ static void sis_old_set_dmamode (struct ata_port *ap, struct ata_device *adev)
         if (adev->dma_mode < XFER_UDMA_0) {
                 /* bits 3-0 hold recovery timing bits 8-10 active timing and
                    the higher bits are dependant on the device */
+                speed = mwdma_clip_to_pio(adev);
                 timing &= ~0x870F;
                 timing |= mwdma_bits[speed];
         } else {
@@ -372,6 +410,7 @@ static void sis_66_set_dmamode (struct ata_port *ap, struct ata_device *adev)
         if (adev->dma_mode < XFER_UDMA_0) {
                 /* bits 3-0 hold recovery timing bits 8-10 active timing and
                    the higher bits are dependant on the device, bit 15 udma */
+                speed = mwdma_clip_to_pio(adev);
                 timing &= ~0x870F;
                 timing |= mwdma_bits[speed];
         } else {
@@ -389,7 +428,7 @@ static void sis_66_set_dmamode (struct ata_port *ap, struct ata_device *adev)
  *      @adev: Device to program
  *
  *      Set UDMA/MWDMA mode for device, in host controller PCI config space.
- *      Handles UDMA66 and early UDMA100 devices.
+ *      Handles later UDMA100 devices.
  *
  *      LOCKING:
  *      None (inherited from caller).
@@ -400,21 +439,25 @@ static void sis_100_set_dmamode (struct ata_port *ap, struct ata_device *adev)
         struct pci_dev *pdev    = to_pci_dev(ap->host->dev);
         int speed = adev->dma_mode - XFER_MW_DMA_0;
         int drive_pci = sis_old_port_base(adev);
-        u8 timing;
+        u16 timing;
 
-        const u8 udma_bits[]  = { 0x8B, 0x87, 0x85, 0x83, 0x82, 0x81};
+        const u16 udma_bits[]  = {
+                0x8B00, 0x8700, 0x8500, 0x8300, 0x8200, 0x8100};
+        const u8 mwdma_bits[] = { 0x08, 0x32, 0x31 };
 
-        pci_read_config_byte(pdev, drive_pci + 1, &timing);
+        pci_read_config_word(pdev, drive_pci, &timing);
 
         if (adev->dma_mode < XFER_UDMA_0) {
-                /* NOT SUPPORTED YET: NEED DATA SHEET. DITTO IN OLD DRIVER */
+                speed = mwdma_clip_to_pio(adev);
+                timing &= ~0x80FF;
+                timing |= mwdma_bits[speed];
         } else {
                 /* Bit 7 is UDMA on/off, bit 0-3 are cycle time */
                 speed = adev->dma_mode - XFER_UDMA_0;
-                timing &= ~0x8F;
+                timing &= ~0x8F00;
                 timing |= udma_bits[speed];
         }
-        pci_write_config_byte(pdev, drive_pci + 1, timing);
+        pci_write_config_word(pdev, drive_pci, timing);
 }
 
 /**
@@ -434,21 +477,26 @@ static void sis_133_early_set_dmamode (struct ata_port *ap, struct ata_device *a
         struct pci_dev *pdev    = to_pci_dev(ap->host->dev);
         int speed = adev->dma_mode - XFER_MW_DMA_0;
         int drive_pci = sis_old_port_base(adev);
-        u8 timing;
-        /* Low 4 bits are timing */
-        static const u8 udma_bits[]  = { 0x8F, 0x8A, 0x87, 0x85, 0x83, 0x82, 0x81};
+        u16 timing;
+        /* Bits 15-12  are timing */
+        static const u16 udma_bits[]  = {
+                0x8F00, 0x8A00, 0x8700, 0x8500, 0x8300, 0x8200, 0x8100
+        };
+        static const u8 mwdma_bits[] = { 0x08, 0x32, 0x31 };
 
-        pci_read_config_byte(pdev, drive_pci + 1, &timing);
+        pci_read_config_word(pdev, drive_pci, &timing);
 
         if (adev->dma_mode < XFER_UDMA_0) {
-                /* NOT SUPPORTED YET: NEED DATA SHEET. DITTO IN OLD DRIVER */
+                speed = mwdma_clip_to_pio(adev);
+                timing &= ~0x80FF;
+                timing = mwdma_bits[speed];
         } else {
                 /* Bit 7 is UDMA on/off, bit 0-3 are cycle time */
                 speed = adev->dma_mode - XFER_UDMA_0;
-                timing &= ~0x8F;
+                timing &= ~0x8F00;
                 timing |= udma_bits[speed];
         }
-        pci_write_config_byte(pdev, drive_pci + 1, timing);
+        pci_write_config_word(pdev, drive_pci, timing);
 }
 
 /**
@@ -479,13 +527,12 @@ static void sis_133_set_dmamode (struct ata_port *ap, struct ata_device *adev)
         if (reg54 & 0x40000000)
                 port = 0x70;
         port += (8 * ap->port_no) +  (4 * adev->devno);
-
         pci_read_config_dword(pdev, port, &t1);
 
         if (adev->dma_mode < XFER_UDMA_0) {
-                t1 &= ~0x00000004;
-                /* FIXME: need data sheet to add MWDMA here. Also lacking on
-                   ide/pci driver */
+                speed = mwdma_clip_to_pio(adev);
+                sis_133_do_piomode(ap, adev, speed);
+                t1 &= ~4;       /* UDMA off */
         } else {
                 speed = adev->dma_mode - XFER_UDMA_0;
                 /* if & 8 no UDMA133 - need info for ... */