opti621: use pre-calculated PIO timings (810253d4) · Commits · 戴 / test

drivers/ide/pci/opti621.c

+15 −77

Original line number	Diff line number	Diff line
		@@ -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 */

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