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opti621: use pre-calculated PIO timings 

* Use pre-calculated PIO timings in ->set_pio_mode.

* Remove no longer needed compute_clocks(), cmpt_clk(), struct pio_clocks_s,
  PIO_* defines and OPTI621_DEBUG define.

There should be no functional changes caused by this patch.

Based on a bugreport from Juergen Kosel & inspired by pata_opti.c code.

Tested-by: Juergen Kosel <juergen.kosel@gmx.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
This commit is contained in:
Bartlomiej Zolnierkiewicz 2008-06-15 21:00:22 +02:00
parent 6c987183fc
commit 810253d44b
1 changed files with 15 additions and 77 deletions
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92
drivers/ide/pci/opti621.c
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@ -81,8 +81,6 @@
* 0.5 doesn't work.
*/
#define OPTI621_DEBUG /* define for debug messages */
#include <linux/types.h>
#include <linux/module.h>
#include <linux/kernel.h>
@ -110,23 +108,8 @@
static int reg_base;
#define PIO_NOT_EXIST 254
#define PIO_DONT_KNOW 255
static DEFINE_SPINLOCK(opti621_lock);
static int cmpt_clk(int time, int bus_speed)
/* Returns (rounded up) time in clocks for time in ns,
* with bus_speed in MHz.
* Example: bus_speed = 40 MHz, time = 80 ns
* 1000/40 = 25 ns (clk value),
* 80/25 = 3.2, rounded up to 4 (I hope ;-)).
* Use idebus=xx to select right frequency.
*/
{
return ((time*bus_speed+999)/1000);
}
/* Write value to register reg, base of register
* is at reg_base (0x1f0 primary, 0x170 secondary,
* if not changed by PCI configuration).
@ -159,51 +142,22 @@ static u8 read_reg(int reg)
return ret;
}
typedef struct pio_clocks_s {
int address_time; /* Address setup (clocks) */
int data_time; /* Active/data pulse (clocks) */
int recovery_time; /* Recovery time (clocks) */
} pio_clocks_t;
static void compute_clocks(int pio, pio_clocks_t *clks, int bus_speed)
{
if (pio != PIO_NOT_EXIST) {
int adr_setup, data_pls;
adr_setup = ide_pio_timings[pio].setup_time;
data_pls = ide_pio_timings[pio].active_time;
clks->address_time = cmpt_clk(adr_setup, bus_speed);
clks->data_time = cmpt_clk(data_pls, bus_speed);
clks->recovery_time = cmpt_clk(ide_pio_timings[pio].cycle_time
- adr_setup-data_pls, bus_speed);
if (clks->address_time < 1)
clks->address_time = 1;
if (clks->address_time > 4)
clks->address_time = 4;
if (clks->data_time < 1)
clks->data_time = 1;
if (clks->data_time > 16)
clks->data_time = 16;
if (clks->recovery_time < 2)
clks->recovery_time = 2;
if (clks->recovery_time > 17)
clks->recovery_time = 17;
} else {
clks->address_time = 1;
clks->data_time = 1;
clks->recovery_time = 2;
/* minimal values */
}
}
static void opti621_set_pio_mode(ide_drive_t *drive, const u8 pio)
{
ide_hwif_t *hwif = drive->hwif;
ide_drive_t *pair = ide_get_paired_drive(drive);
unsigned long flags;
pio_clocks_t first, second;
int ax, drdy;
u8 cycle1, misc, clk, addr_pio = pio;
u8 tim, misc, addr_pio = pio, clk;
/* DRDY is default 2 (by OPTi Databook) */
static const u8 addr_timings[2][4] = {
{ 0x20, 0x10, 0x00, 0x00 }, /* 33 MHz */
{ 0x10, 0x10, 0x00, 0x00 }, /* 25 MHz */
};
static const u8 data_rec_timings[2][4] = {
{ 0x5b, 0x45, 0x32, 0x21 }, /* 33 MHz */
{ 0x48, 0x34, 0x21, 0x10 } /* 25 MHz */
};
drive->drive_data = XFER_PIO_0 + pio;
@ -230,31 +184,15 @@ static void opti621_set_pio_mode(ide_drive_t *drive, const u8 pio)
printk(KERN_INFO "%s: CLK = %d MHz\n", hwif->name, clk ? 25 : 33);
compute_clocks(pio, &first, clk ? 25 : 33);
compute_clocks(addr_pio, &second, clk ? 25 : 33);
/* ax = max(a1,a2) */
ax = (first.address_time < second.address_time) ? second.address_time : first.address_time;
drdy = 2; /* DRDY is default 2 (by OPTi Databook) */
cycle1 = ((first.data_time-1)<<4) | (first.recovery_time-2);
misc = ((ax - 1) << 4) | ((drdy - 2) << 1);
#ifdef OPTI621_DEBUG
printk("%s: address: %d, data: %d, "
"recovery: %d, drdy: %d [clk]\n",
drive->name, ax, first.data_time,
first.recovery_time, drdy);
#endif
tim = data_rec_timings[clk][pio];
misc = addr_timings[clk][addr_pio];
/* select Index-0/1 for Register-A/B */
write_reg(drive->select.b.unit, MISC_REG);
/* set read cycle timings */
write_reg(cycle1, READ_REG);
write_reg(tim, READ_REG);
/* set write cycle timings */
write_reg(cycle1, WRITE_REG);
write_reg(tim, WRITE_REG);
/* use Register-A for drive 0 */
/* use Register-B for drive 1 */