sl82c105: rework PIO support (take 2)

Get rid of the 'pio_speed' member of 'ide_drive_t' that was only used by this
driver by storing the PIO mode timings in the 'drive_data' instead -- this
allows us to greatly  simplify the process of "reloading" of the chip's timing
register and do it right in sl82c150_dma_off_quietly() and to get rid of two
extra arguments to config_for_pio() -- which got renamed to sl82c105_tune_pio()
and now returns a PIO mode selected, with ide_config_drive_speed() call moved
into the tuneproc() method, now called sl82c105_tune_drive() with the code to
set drive's 'io_32bit' and 'unmask' flags in its turn moved to its proper place
in the init_hwif() method.
Also, while at it, rename get_timing_sl82c105() into get_pio_timings() and get
rid of the code in it clamping cycle counts to 32 which was both incorrect and
never executed anyway...

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

1 files changed, 41 insertions, 58 deletions

diff --git a/drivers/ide/pci/sl82c105.c b/drivers/ide/pci/sl82c105.c
index 3a8a76fc78c7..ee6dd45a9ba7 100644
--- a/drivers/ide/pci/sl82c105.c
+++ b/drivers/ide/pci/sl82c105.c
@@ -11,6 +11,8 @@
  * Merge in Russell's HW workarounds, fix various problems
  * with the timing registers setup.
  *  -- Benjamin Herrenschmidt (01/11/03) benh@kernel.crashing.org
+ *
+ * Copyright (C) 2006-2007 MontaVista Software, Inc. <source@mvista.com>
  */
 
 #include <linux/types.h>
@@ -47,25 +49,19 @@
 #define CTRL_P0EN       (1 << 0)
 
 /*
- * Convert a PIO mode and cycle time to the required on/off
- * times for the interface.  This has protection against run-away
- * timings.
+ * Convert a PIO mode and cycle time to the required on/off times
+ * for the interface.  This has protection against runaway timings.
  */
-static unsigned int get_timing_sl82c105(ide_pio_data_t *p)
+static unsigned int get_pio_timings(ide_pio_data_t *p)
 {
-        unsigned int cmd_on;
-        unsigned int cmd_off;
+        unsigned int cmd_on, cmd_off;
 
-        cmd_on = (ide_pio_timings[p->pio_mode].active_time + 29) / 30;
+        cmd_on  = (ide_pio_timings[p->pio_mode].active_time + 29) / 30;
         cmd_off = (p->cycle_time - 30 * cmd_on + 29) / 30;
 
-        if (cmd_on > 32)
-                cmd_on = 32;
         if (cmd_on == 0)
                 cmd_on = 1;
 
-        if (cmd_off > 32)
-                cmd_off = 32;
         if (cmd_off == 0)
                 cmd_off = 1;
 
@@ -73,44 +69,34 @@ static unsigned int get_timing_sl82c105(ide_pio_data_t *p)
 }
 
 /*
- * Configure the drive and chipset for PIO
+ * Configure the chipset for PIO mode.
  */
-static void config_for_pio(ide_drive_t *drive, int pio, int report, int chipset_only)
+static u8 sl82c105_tune_pio(ide_drive_t *drive, u8 pio)
 {
-        ide_hwif_t *hwif = HWIF(drive);
-        struct pci_dev *dev = hwif->pci_dev;
+        struct pci_dev *dev     = HWIF(drive)->pci_dev;
+        int reg                 = 0x44 + drive->dn * 4;
         ide_pio_data_t p;
-        u16 drv_ctrl = 0x909;
-        unsigned int xfer_mode, reg;
+        u16 drv_ctrl;
 
-        DBG(("config_for_pio(drive:%s, pio:%d, report:%d, chipset_only:%d)\n",
-                drive->name, pio, report, chipset_only));
-                
-        reg = (hwif->channel ? 0x4c : 0x44) + (drive->select.b.unit ? 4 : 0);
+        DBG(("sl82c105_tune_pio(drive:%s, pio:%u)\n", drive->name, pio));
 
         pio = ide_get_best_pio_mode(drive, pio, 5, &p);
 
-        xfer_mode = XFER_PIO_0 + pio;
+        drive->drive_data = drv_ctrl = get_pio_timings(&p);
 
-        if (chipset_only || ide_config_drive_speed(drive, xfer_mode) == 0) {
-                drv_ctrl = get_timing_sl82c105(&p);
-                drive->pio_speed = xfer_mode;
-        } else
-                drive->pio_speed = XFER_PIO_0;
-
-        if (drive->using_dma == 0) {
+        if (!drive->using_dma) {
                 /*
                  * If we are actually using MW DMA, then we can not
                  * reprogram the interface drive control register.
                  */
-                pci_write_config_word(dev, reg, drv_ctrl);
-                pci_read_config_word(dev, reg, &drv_ctrl);
-
-                if (report) {
-                        printk("%s: selected %s (%dns) (%04X)\n", drive->name,
-                               ide_xfer_verbose(xfer_mode), p.cycle_time, drv_ctrl);
-                }
+                pci_write_config_word(dev, reg,  drv_ctrl);
+                pci_read_config_word (dev, reg, &drv_ctrl);
         }
+
+        printk(KERN_DEBUG "%s: selected %s (%dns) (%04X)\n", drive->name,
+               ide_xfer_verbose(pio + XFER_PIO_0), p.cycle_time, drv_ctrl);
+
+        return pio;
 }
 
 /*
@@ -267,14 +253,14 @@ static int sl82c105_ide_dma_on (ide_drive_t *drive)
 
 static void sl82c105_dma_off_quietly(ide_drive_t *drive)
 {
-        u8 speed = XFER_PIO_0;
+        struct pci_dev *dev     = HWIF(drive)->pci_dev;
+        int reg                 = 0x44 + drive->dn * 4;
 
         DBG(("sl82c105_dma_off_quietly(drive:%s)\n", drive->name));
 
+        pci_write_config_word(dev, reg, drive->drive_data);
+
         ide_dma_off_quietly(drive);
-        if (drive->pio_speed)
-                speed = drive->pio_speed - XFER_PIO_0;
-        config_for_pio(drive, speed, 0, 1);
 }
 
 /*
@@ -323,18 +309,12 @@ static void sl82c105_resetproc(ide_drive_t *drive)
  * We only deal with PIO mode here - DMA mode 'using_dma' is not
  * initialised at the point that this function is called.
  */
-static void tune_sl82c105(ide_drive_t *drive, u8 pio)
+static void sl82c105_tune_drive(ide_drive_t *drive, u8 pio)
 {
-        DBG(("tune_sl82c105(drive:%s)\n", drive->name));
+        DBG(("sl82c105_tune_drive(drive:%s, pio:%u)\n", drive->name, pio));
 
-        config_for_pio(drive, pio, 1, 0);
-
-        /*
-         * We support 32-bit I/O on this interface, and it
-         * doesn't have problems with interrupts.
-         */
-        drive->io_32bit = 1;
-        drive->unmask = 1;
+        pio = sl82c105_tune_pio(drive, pio);
+        (void) ide_config_drive_speed(drive, XFER_PIO_0 + pio);
 }
 
 /*
@@ -401,19 +381,22 @@ static void __devinit init_hwif_sl82c105(ide_hwif_t *hwif)
 
         DBG(("init_hwif_sl82c105(hwif: ide%d)\n", hwif->index));
 
-        hwif->tuneproc = tune_sl82c105;
-        hwif->selectproc = sl82c105_selectproc;
-        hwif->resetproc = sl82c105_resetproc;
+        hwif->tuneproc          = &sl82c105_tune_drive;
+        hwif->selectproc        = &sl82c105_selectproc;
+        hwif->resetproc         = &sl82c105_resetproc;
+
+        /*
+         * We support 32-bit I/O on this interface, and
+         * it doesn't have problems with interrupts.
+         */
+        hwif->drives[0].io_32bit = hwif->drives[1].io_32bit = 1;
+        hwif->drives[0].unmask   = hwif->drives[1].unmask   = 1;
 
         /*
-         * Default to PIO 0 for fallback unless tuned otherwise.
          * We always autotune PIO,  this is done before DMA is checked,
          * so there's no risk of accidentally disabling DMA
          */
-        hwif->drives[0].pio_speed = XFER_PIO_0;
-        hwif->drives[0].autotune = 1;
-        hwif->drives[1].pio_speed = XFER_PIO_0;
-        hwif->drives[1].autotune = 1;
+        hwif->drives[0].autotune = hwif->drives[1].autotune = 1;
 
         hwif->atapi_dma = 0;
         hwif->mwdma_mask = 0;