pata_atp867x: clarifications in timings calculations and cable detection

Signed-off-by: John(Jung-Ik) Lee <jilee@google.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 38 insertions, 14 deletions

diff --git a/drivers/ata/pata_atp867x.c b/drivers/ata/pata_atp867x.c
index ebfc8ff86519..27d3148b3d8e 100644
--- a/drivers/ata/pata_atp867x.c
+++ b/drivers/ata/pata_atp867x.c
@@ -149,8 +149,10 @@ static void atp867x_set_dmamode(struct ata_port *ap, struct ata_device *adev)
         iowrite8(b, dp->dma_mode);
 }
 
-static int atp867x_get_active_clocks_shifted(unsigned int clk)
+static int atp867x_get_active_clocks_shifted(struct ata_port *ap,
+        unsigned int clk)
 {
+        struct atp867x_priv *dp = ap->private_data;
         unsigned char clocks = clk;
 
         switch (clocks) {
@@ -159,15 +161,25 @@ static int atp867x_get_active_clocks_shifted(unsigned int clk)
                 break;
         case 1 ... 7:
                 break;
-        case 8 ... 12:
+        case 9 ... 12:
                 clocks = 7;
                 break;
         default:
                 printk(KERN_WARNING "ATP867X: active %dclk is invalid. "
                         "Using default 8clk.\n", clk);
-                clocks = 0;     /* 8 clk */
-                break;
+        case 8: /* default 8 clk */
+                clocks = 0;
+                goto active_clock_shift_done;
         }
+
+        /*
+         * Doc 6.6.9: increase the clock value by 1 for safer PIO speed
+         * on 66MHz bus
+         */
+        if (dp->pci66mhz && clocks < 7)
+                clocks++;
+
+active_clock_shift_done:
         return clocks << ATP867X_IO_PIOSPD_ACTIVE_SHIFT;
 }
 
@@ -181,20 +193,19 @@ static int atp867x_get_recover_clocks_shifted(unsigned int clk)
                 break;
         case 1 ... 11:
                 break;
-        case 12:
-                clocks = 0;
-                break;
         case 13: case 14:
-                --clocks;
+                --clocks;       /* by the spec */
                 break;
         case 15:
                 break;
         default:
                 printk(KERN_WARNING "ATP867X: recover %dclk is invalid. "
-                        "Using default 15clk.\n", clk);
-                clocks = 0;     /* 12 clk */
+                        "Using default 12clk.\n", clk);
+        case 12:        /* default 12 clk */
+                clocks = 0;
                 break;
         }
+
         return clocks << ATP867X_IO_PIOSPD_RECOVER_SHIFT;
 }
 
@@ -223,10 +234,8 @@ static void atp867x_set_piomode(struct ata_port *ap, struct ata_device *adev)
                 b = (b & ~ATP867X_IO_DMAMODE_MSTR_MASK);
         iowrite8(b, dp->dma_mode);
 
-        b = atp867x_get_active_clocks_shifted(t.active) |
+        b = atp867x_get_active_clocks_shifted(ap, t.active) |
                 atp867x_get_recover_clocks_shifted(t.recover);
-        if (dp->pci66mhz)
-                b += 0x10;
 
         if (adev->devno & 1)
                 iowrite8(b, dp->slave_piospd);
@@ -239,9 +248,24 @@ static void atp867x_set_piomode(struct ata_port *ap, struct ata_device *adev)
         iowrite8(b, dp->eightb_piospd);
 }
 
+static int atp867x_cable_override(struct pci_dev *pdev)
+{
+        if (pdev->subsystem_vendor == PCI_VENDOR_ID_ARTOP &&
+                (pdev->subsystem_device == PCI_DEVICE_ID_ARTOP_ATP867A ||
+                 pdev->subsystem_device == PCI_DEVICE_ID_ARTOP_ATP867B)) {
+                return 1;
+        }
+        return 0;
+}
+
 static int atp867x_cable_detect(struct ata_port *ap)
 {
-        return ATA_CBL_PATA40_SHORT;
+        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
+
+        if (atp867x_cable_override(pdev))
+                return ATA_CBL_PATA40_SHORT;
+
+        return ATA_CBL_PATA_UNK;
 }
 
 static struct scsi_host_template atp867x_sht = {