+++ /dev/null
-/*
- * comedi/drivers/8253.h
- * Header file for 8253
- *
- * COMEDI - Linux Control and Measurement Device Interface
- * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#ifndef _8253_H
-#define _8253_H
-
-#include "../comedi.h"
-
-/*
- * Common oscillator base values in nanoseconds
- */
-#define I8254_OSC_BASE_10MHZ 100
-#define I8254_OSC_BASE_5MHZ 200
-#define I8254_OSC_BASE_4MHZ 250
-#define I8254_OSC_BASE_2MHZ 500
-#define I8254_OSC_BASE_1MHZ 1000
-
-static inline void i8253_cascade_ns_to_timer(int i8253_osc_base,
- unsigned int *d1,
- unsigned int *d2,
- unsigned int *nanosec,
- unsigned int flags)
-{
- unsigned int divider;
- unsigned int div1, div2;
- unsigned int div1_glb, div2_glb, ns_glb;
- unsigned int div1_lub, div2_lub, ns_lub;
- unsigned int ns;
- unsigned int start;
- unsigned int ns_low, ns_high;
- static const unsigned int max_count = 0x10000;
- /*
- * exit early if everything is already correct (this can save time
- * since this function may be called repeatedly during command tests
- * and execution)
- */
- div1 = *d1 ? *d1 : max_count;
- div2 = *d2 ? *d2 : max_count;
- divider = div1 * div2;
- if (div1 * div2 * i8253_osc_base == *nanosec &&
- div1 > 1 && div1 <= max_count && div2 > 1 && div2 <= max_count &&
- /* check for overflow */
- divider > div1 && divider > div2 &&
- divider * i8253_osc_base > divider &&
- divider * i8253_osc_base > i8253_osc_base) {
- return;
- }
-
- divider = *nanosec / i8253_osc_base;
-
- div1_lub = div2_lub = 0;
- div1_glb = div2_glb = 0;
-
- ns_glb = 0;
- ns_lub = 0xffffffff;
-
- div2 = max_count;
- start = divider / div2;
- if (start < 2)
- start = 2;
- for (div1 = start; div1 <= divider / div1 + 1 && div1 <= max_count;
- div1++) {
- for (div2 = divider / div1;
- div1 * div2 <= divider + div1 + 1 && div2 <= max_count;
- div2++) {
- ns = i8253_osc_base * div1 * div2;
- if (ns <= *nanosec && ns > ns_glb) {
- ns_glb = ns;
- div1_glb = div1;
- div2_glb = div2;
- }
- if (ns >= *nanosec && ns < ns_lub) {
- ns_lub = ns;
- div1_lub = div1;
- div2_lub = div2;
- }
- }
- }
-
- switch (flags & CMDF_ROUND_MASK) {
- case CMDF_ROUND_NEAREST:
- default:
- ns_high = div1_lub * div2_lub * i8253_osc_base;
- ns_low = div1_glb * div2_glb * i8253_osc_base;
- if (ns_high - *nanosec < *nanosec - ns_low) {
- div1 = div1_lub;
- div2 = div2_lub;
- } else {
- div1 = div1_glb;
- div2 = div2_glb;
- }
- break;
- case CMDF_ROUND_UP:
- div1 = div1_lub;
- div2 = div2_lub;
- break;
- case CMDF_ROUND_DOWN:
- div1 = div1_glb;
- div2 = div2_glb;
- break;
- }
-
- *nanosec = div1 * div2 * i8253_osc_base;
- /* masking is done since counter maps zero to 0x10000 */
- *d1 = div1 & 0xffff;
- *d2 = div2 & 0xffff;
-}
-
-#ifndef CMDTEST
-/*
- * i8254_load programs 8254 counter chip. It should also work for the 8253.
- * base_address is the lowest io address
- * for the chip (the address of counter 0).
- * counter_number is the counter you want to load (0,1 or 2)
- * count is the number to load into the counter.
- *
- * You probably want to use mode 2.
- *
- * Use i8254_mm_load() if you board uses memory-mapped io, it is
- * the same as i8254_load() except it uses writeb() instead of outb().
- *
- * Neither i8254_load() or i8254_read() do their loading/reading
- * atomically. The 16 bit read/writes are performed with two successive
- * 8 bit read/writes. So if two parts of your driver do a load/read on
- * the same counter, it may be necessary to protect these functions
- * with a spinlock.
- *
- * FMH
- */
-
-#define i8254_control_reg 3
-
-static inline int i8254_load(unsigned long base_address, unsigned int regshift,
- unsigned int counter_number, unsigned int count,
- unsigned int mode)
-{
- unsigned int byte;
-
- if (counter_number > 2)
- return -1;
- if (count > 0xffff)
- return -1;
- if (mode > 5)
- return -1;
- if ((mode == 2 || mode == 3) && count == 1)
- return -1;
-
- byte = counter_number << 6;
- byte |= 0x30; /* load low then high byte */
- byte |= (mode << 1); /* set counter mode */
- outb(byte, base_address + (i8254_control_reg << regshift));
- byte = count & 0xff; /* lsb of counter value */
- outb(byte, base_address + (counter_number << regshift));
- byte = (count >> 8) & 0xff; /* msb of counter value */
- outb(byte, base_address + (counter_number << regshift));
-
- return 0;
-}
-
-static inline int i8254_mm_load(void __iomem *base_address,
- unsigned int regshift,
- unsigned int counter_number,
- unsigned int count,
- unsigned int mode)
-{
- unsigned int byte;
-
- if (counter_number > 2)
- return -1;
- if (count > 0xffff)
- return -1;
- if (mode > 5)
- return -1;
- if ((mode == 2 || mode == 3) && count == 1)
- return -1;
-
- byte = counter_number << 6;
- byte |= 0x30; /* load low then high byte */
- byte |= (mode << 1); /* set counter mode */
- writeb(byte, base_address + (i8254_control_reg << regshift));
- byte = count & 0xff; /* lsb of counter value */
- writeb(byte, base_address + (counter_number << regshift));
- byte = (count >> 8) & 0xff; /* msb of counter value */
- writeb(byte, base_address + (counter_number << regshift));
-
- return 0;
-}
-
-/* Returns 16 bit counter value, should work for 8253 also. */
-static inline int i8254_read(unsigned long base_address, unsigned int regshift,
- unsigned int counter_number)
-{
- unsigned int byte;
- int ret;
-
- if (counter_number > 2)
- return -1;
-
- /* latch counter */
- byte = counter_number << 6;
- outb(byte, base_address + (i8254_control_reg << regshift));
-
- /* read lsb */
- ret = inb(base_address + (counter_number << regshift));
- /* read msb */
- ret += inb(base_address + (counter_number << regshift)) << 8;
-
- return ret;
-}
-
-static inline int i8254_mm_read(void __iomem *base_address,
- unsigned int regshift,
- unsigned int counter_number)
-{
- unsigned int byte;
- int ret;
-
- if (counter_number > 2)
- return -1;
-
- /* latch counter */
- byte = counter_number << 6;
- writeb(byte, base_address + (i8254_control_reg << regshift));
-
- /* read lsb */
- ret = readb(base_address + (counter_number << regshift));
- /* read msb */
- ret += readb(base_address + (counter_number << regshift)) << 8;
-
- return ret;
-}
-
-/* Loads 16 bit initial counter value, should work for 8253 also. */
-static inline void i8254_write(unsigned long base_address,
- unsigned int regshift,
- unsigned int counter_number, unsigned int count)
-{
- unsigned int byte;
-
- if (counter_number > 2)
- return;
-
- byte = count & 0xff; /* lsb of counter value */
- outb(byte, base_address + (counter_number << regshift));
- byte = (count >> 8) & 0xff; /* msb of counter value */
- outb(byte, base_address + (counter_number << regshift));
-}
-
-static inline void i8254_mm_write(void __iomem *base_address,
- unsigned int regshift,
- unsigned int counter_number,
- unsigned int count)
-{
- unsigned int byte;
-
- if (counter_number > 2)
- return;
-
- byte = count & 0xff; /* lsb of counter value */
- writeb(byte, base_address + (counter_number << regshift));
- byte = (count >> 8) & 0xff; /* msb of counter value */
- writeb(byte, base_address + (counter_number << regshift));
-}
-
-/*
- * Set counter mode, should work for 8253 also.
- * Note: the 'mode' value is different to that for i8254_load() and comes
- * from the INSN_CONFIG_8254_SET_MODE command:
- * I8254_MODE0, I8254_MODE1, ..., I8254_MODE5
- * OR'ed with:
- * I8254_BCD, I8254_BINARY
- */
-static inline int i8254_set_mode(unsigned long base_address,
- unsigned int regshift,
- unsigned int counter_number, unsigned int mode)
-{
- unsigned int byte;
-
- if (counter_number > 2)
- return -1;
- if (mode > (I8254_MODE5 | I8254_BCD))
- return -1;
-
- byte = counter_number << 6;
- byte |= 0x30; /* load low then high byte */
- byte |= mode; /* set counter mode and BCD|binary */
- outb(byte, base_address + (i8254_control_reg << regshift));
-
- return 0;
-}
-
-static inline int i8254_mm_set_mode(void __iomem *base_address,
- unsigned int regshift,
- unsigned int counter_number,
- unsigned int mode)
-{
- unsigned int byte;
-
- if (counter_number > 2)
- return -1;
- if (mode > (I8254_MODE5 | I8254_BCD))
- return -1;
-
- byte = counter_number << 6;
- byte |= 0x30; /* load low then high byte */
- byte |= mode; /* set counter mode and BCD|binary */
- writeb(byte, base_address + (i8254_control_reg << regshift));
-
- return 0;
-}
-
-static inline int i8254_status(unsigned long base_address,
- unsigned int regshift,
- unsigned int counter_number)
-{
- outb(0xE0 | (2 << counter_number),
- base_address + (i8254_control_reg << regshift));
- return inb(base_address + (counter_number << regshift));
-}
-
-static inline int i8254_mm_status(void __iomem *base_address,
- unsigned int regshift,
- unsigned int counter_number)
-{
- writeb(0xE0 | (2 << counter_number),
- base_address + (i8254_control_reg << regshift));
- return readb(base_address + (counter_number << regshift));
-}
-
-#endif
-
-#endif
projects / openwrt / staging / blogic.git / commitdiff