--- /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.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef _8253_H
+#define _8253_H
+
+#ifndef CMDTEST
+#include "../comedi.h"
+#else
+#include "../comedi.h"
+#endif
+
+#define i8253_cascade_ns_to_timer i8253_cascade_ns_to_timer_2div
+
+static inline void i8253_cascade_ns_to_timer_2div_old(int i8253_osc_base,
+ unsigned int *d1, unsigned int *d2, unsigned int *nanosec,
+ int round_mode)
+{
+ int divider;
+ int div1, div2;
+ int div1_glb, div2_glb, ns_glb;
+ int div1_lub, div2_lub, ns_lub;
+ int ns;
+
+ divider = (*nanosec + i8253_osc_base / 2) / i8253_osc_base;
+
+ /* find 2 integers 1<={x,y}<=65536 such that x*y is
+ close to divider */
+
+ div1_lub = div2_lub = 0;
+ div1_glb = div2_glb = 0;
+
+ ns_glb = 0;
+ ns_lub = 0xffffffff;
+
+ div2 = 0x10000;
+ for (div1 = divider / 65536 + 1; div1 < div2; div1++) {
+ div2 = divider / div1;
+
+ ns = i8253_osc_base * div1 * div2;
+ if (ns <= *nanosec && ns > ns_glb) {
+ ns_glb = ns;
+ div1_glb = div1;
+ div2_glb = div2;
+ }
+
+ div2++;
+ if (div2 <= 65536) {
+ ns = i8253_osc_base * div1 * div2;
+ if (ns > *nanosec && ns < ns_lub) {
+ ns_lub = ns;
+ div1_lub = div1;
+ div2_lub = div2;
+ }
+ }
+ }
+
+ *nanosec = div1_lub * div2_lub * i8253_osc_base;
+ *d1 = div1_lub & 0xffff;
+ *d2 = div2_lub & 0xffff;
+ return;
+}
+
+static inline void i8253_cascade_ns_to_timer_power(int i8253_osc_base,
+ unsigned int *d1, unsigned int *d2, unsigned int *nanosec,
+ int round_mode)
+{
+ int div1, div2;
+ int base;
+
+ for (div1 = 2; div1 <= (1 << 16); div1 <<= 1) {
+ base = i8253_osc_base * div1;
+ round_mode &= TRIG_ROUND_MASK;
+ switch (round_mode) {
+ case TRIG_ROUND_NEAREST:
+ default:
+ div2 = (*nanosec + base / 2) / base;
+ break;
+ case TRIG_ROUND_DOWN:
+ div2 = (*nanosec) / base;
+ break;
+ case TRIG_ROUND_UP:
+ div2 = (*nanosec + base - 1) / base;
+ break;
+ }
+ if (div2 < 2)
+ div2 = 2;
+ if (div2 <= 65536) {
+ *nanosec = div2 * base;
+ *d1 = div1 & 0xffff;
+ *d2 = div2 & 0xffff;
+ return;
+ }
+ }
+
+ /* shouldn't get here */
+ div1 = 0x10000;
+ div2 = 0x10000;
+ *nanosec = div1 * div2 * i8253_osc_base;
+ *d1 = div1 & 0xffff;
+ *d2 = div2 & 0xffff;
+}
+
+static inline void i8253_cascade_ns_to_timer_2div(int i8253_osc_base,
+ unsigned int *d1, unsigned int *d2, unsigned int *nanosec,
+ int round_mode)
+{
+ 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;
+ }
+ }
+ }
+
+ round_mode &= TRIG_ROUND_MASK;
+ switch (round_mode) {
+ case TRIG_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 TRIG_ROUND_UP:
+ div1 = div1_lub;
+ div2 = div2_lub;
+ break;
+ case TRIG_ROUND_DOWN:
+ div1 = div1_glb;
+ div2 = div2_glb;
+ break;
+ }
+
+ *nanosec = div1 * div2 * i8253_osc_base;
+ *d1 = div1 & 0xffff; // masking is done since counter maps zero to 0x10000
+ *d2 = div2 & 0xffff;
+ return;
+}
+
+#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 *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 *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 *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_BINARY))
+ 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 *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_BINARY))
+ 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 *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 / linux-2.6-omap-h63xx.git / blobdiff