lkml.org 
[lkml]   [2010]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH 33/64] cy82c693: fix PIO timings calculations
From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Subject: [PATCH] cy82c693: fix PIO timings calculations

Just use the standard ide_timing_compute() helper to calculate
PIO timings. This fixes many issues with the open-coded version
like using 16-bit timings when 8-bit ones should be used or not
accounting for the enhanced cycle time specified by the device.

Based on libata pata_cypress host driver.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
---
drivers/ide/cy82c693.c | 106 +++++++++----------------------------------------
1 file changed, 20 insertions(+), 86 deletions(-)
Index: b/drivers/ide/cy82c693.c
===================================================================
--- a/drivers/ide/cy82c693.c
+++ b/drivers/ide/cy82c693.c
@@ -1,6 +1,7 @@
/*
* Copyright (C) 1998-2000 Andreas S. Krebs (akrebs@altavista.net), Maintainer
* Copyright (C) 1998-2002 Andre Hedrick <andre@linux-ide.org>, Integrator
+ * Copyright (C) 2007-2010 Bartlomiej Zolnierkiewicz
*
* CYPRESS CY82C693 chipset IDE controller
*
@@ -81,80 +82,6 @@
#define CY82_INDEX_CHANNEL1 0x31
#define CY82_INDEX_TIMEOUT 0x32

-/* the min and max PCI bus speed in MHz - from datasheet */
-#define CY82C963_MIN_BUS_SPEED 25
-#define CY82C963_MAX_BUS_SPEED 33
-
-/* the struct for the PIO mode timings */
-typedef struct pio_clocks_s {
- u8 address_time; /* Address setup (clocks) */
- u8 time_16r; /* clocks for 16bit IOR (0xF0=Active/data, 0x0F=Recovery) */
- u8 time_16w; /* clocks for 16bit IOW (0xF0=Active/data, 0x0F=Recovery) */
- u8 time_8; /* clocks for 8bit (0xF0=Active/data, 0x0F=Recovery) */
-} pio_clocks_t;
-
-/*
- * calc clocks using bus_speed
- * returns (rounded up) time in bus clocks for time in ns
- */
-static int calc_clk(int time, int bus_speed)
-{
- int clocks;
-
- clocks = (time*bus_speed+999)/1000 - 1;
-
- if (clocks < 0)
- clocks = 0;
-
- if (clocks > 0x0F)
- clocks = 0x0F;
-
- return clocks;
-}
-
-/*
- * compute the values for the clock registers for PIO
- * mode and pci_clk [MHz] speed
- *
- * NOTE: for mode 0,1 and 2 drives 8-bit IDE command control registers are used
- * for mode 3 and 4 drives 8 and 16-bit timings are the same
- *
- */
-static void compute_clocks(u8 pio, pio_clocks_t *p_pclk)
-{
- struct ide_timing *t = ide_timing_find_mode(XFER_PIO_0 + pio);
- int clk1, clk2;
- int bus_speed = ide_pci_clk ? ide_pci_clk : 33;
-
- /* we don't check against CY82C693's min and max speed,
- * so you can play with the idebus=xx parameter
- */
-
- /* let's calc the address setup time clocks */
- p_pclk->address_time = (u8)calc_clk(t->setup, bus_speed);
-
- /* let's calc the active and recovery time clocks */
- clk1 = calc_clk(t->active, bus_speed);
-
- /* calc recovery timing */
- clk2 = t->cycle - t->active - t->setup;
-
- clk2 = calc_clk(clk2, bus_speed);
-
- clk1 = (clk1<<4)|clk2; /* combine active and recovery clocks */
-
- /* note: we use the same values for 16bit IOR and IOW
- * those are all the same, since I don't have other
- * timings than those from ide-lib.c
- */
-
- p_pclk->time_16r = (u8)clk1;
- p_pclk->time_16w = (u8)clk1;
-
- /* what are good values for 8bit ?? */
- p_pclk->time_8 = (u8)clk1;
-}
-
/*
* set DMA mode a specific channel for CY82C693
*/
@@ -190,8 +117,11 @@ static void cy82c693_set_pio_mode(ide_dr
{
ide_hwif_t *hwif = drive->hwif;
struct pci_dev *dev = to_pci_dev(hwif->dev);
- pio_clocks_t pclk;
+ int bus_speed = ide_pci_clk ? ide_pci_clk : 33;
+ const unsigned long T = 1000000 / bus_speed;
unsigned int addrCtrl;
+ struct ide_timing t;
+ u8 time_16, time_8;

/* select primary or secondary channel */
if (hwif->index > 0) { /* drive is on the secondary channel */
@@ -204,8 +134,12 @@ static void cy82c693_set_pio_mode(ide_dr
}
}

- /* let's calc the values for this PIO mode */
- compute_clocks(pio, &pclk);
+ ide_timing_compute(drive, XFER_PIO_0 + pio, &t, T, 1);
+
+ time_16 = clamp_val(t.recover - 1, 0, 15) |
+ (clamp_val(t.active - 1, 0, 15) << 4);
+ time_8 = clamp_val(t.act8b - 1, 0, 15) |
+ (clamp_val(t.rec8b - 1, 0, 15) << 4);

/* now let's write the clocks registers */
if ((drive->dn & 1) == 0) {
@@ -217,13 +151,13 @@ static void cy82c693_set_pio_mode(ide_dr
pci_read_config_dword(dev, CY82_IDE_ADDRSETUP, &addrCtrl);

addrCtrl &= (~0xF);
- addrCtrl |= (unsigned int)pclk.address_time;
+ addrCtrl |= clamp_val(t.setup - 1, 0, 15);
pci_write_config_dword(dev, CY82_IDE_ADDRSETUP, addrCtrl);

/* now let's set the remaining registers */
- pci_write_config_byte(dev, CY82_IDE_MASTER_IOR, pclk.time_16r);
- pci_write_config_byte(dev, CY82_IDE_MASTER_IOW, pclk.time_16w);
- pci_write_config_byte(dev, CY82_IDE_MASTER_8BIT, pclk.time_8);
+ pci_write_config_byte(dev, CY82_IDE_MASTER_IOR, time_16);
+ pci_write_config_byte(dev, CY82_IDE_MASTER_IOW, time_16);
+ pci_write_config_byte(dev, CY82_IDE_MASTER_8BIT, time_8);
} else {
/*
* set slave drive
@@ -233,13 +167,13 @@ static void cy82c693_set_pio_mode(ide_dr
pci_read_config_dword(dev, CY82_IDE_ADDRSETUP, &addrCtrl);

addrCtrl &= (~0xF0);
- addrCtrl |= ((unsigned int)pclk.address_time<<4);
+ addrCtrl |= (clamp_val(t.setup - 1, 0, 15) << 4);
pci_write_config_dword(dev, CY82_IDE_ADDRSETUP, addrCtrl);

/* now let's set the remaining registers */
- pci_write_config_byte(dev, CY82_IDE_SLAVE_IOR, pclk.time_16r);
- pci_write_config_byte(dev, CY82_IDE_SLAVE_IOW, pclk.time_16w);
- pci_write_config_byte(dev, CY82_IDE_SLAVE_8BIT, pclk.time_8);
+ pci_write_config_byte(dev, CY82_IDE_SLAVE_IOR, time_16);
+ pci_write_config_byte(dev, CY82_IDE_SLAVE_IOW, time_16);
+ pci_write_config_byte(dev, CY82_IDE_SLAVE_8BIT, time_8);
}
}

@@ -325,6 +259,6 @@ static void __exit cy82c693_ide_exit(voi
module_init(cy82c693_ide_init);
module_exit(cy82c693_ide_exit);

-MODULE_AUTHOR("Andreas Krebs, Andre Hedrick");
+MODULE_AUTHOR("Andreas Krebs, Andre Hedrick, Bartlomiej Zolnierkiewicz");
MODULE_DESCRIPTION("PCI driver module for the Cypress CY82C693 IDE");
MODULE_LICENSE("GPL");

\
 
 \ /
  Last update: 2010-01-18 18:33    [from the cache]
©2003-2011 Jasper Spaans