LXR linux/drivers/staging/comedi/drivers/comedi

   1/*
   2 * comedi_8254.h
   3 * Generic 8254 timer/counter support
   4 * Copyright (C) 2014 H Hartley Sweeten <hsweeten@visionengravers.com>
   5 *
   6 * COMEDI - Linux Control and Measurement Device Interface
   7 * Copyright (C) 2000 David A. Schleef <ds@schleef.org>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2 of the License, or
  12 * (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 */
  19
  20#ifndef _COMEDI_8254_H
  21#define _COMEDI_8254_H
  22
  23#include <linux/types.h>
  24
  25struct comedi_device;
  26struct comedi_insn;
  27struct comedi_subdevice;
  28
  29/*
  30 * Common oscillator base values in nanoseconds
  31 */
  32#define I8254_OSC_BASE_10MHZ    100
  33#define I8254_OSC_BASE_5MHZ     200
  34#define I8254_OSC_BASE_4MHZ     250
  35#define I8254_OSC_BASE_2MHZ     500
  36#define I8254_OSC_BASE_1MHZ     1000
  37#define I8254_OSC_BASE_100KHZ   10000
  38#define I8254_OSC_BASE_10KHZ    100000
  39#define I8254_OSC_BASE_1KHZ     1000000
  40
  41/*
  42 * I/O access size used to read/write registers
  43 */
  44#define I8254_IO8               1
  45#define I8254_IO16              2
  46#define I8254_IO32              4
  47
  48/*
  49 * Register map for generic 8254 timer (I8254_IO8 with 0 regshift)
  50 */
  51#define I8254_COUNTER0_REG              0x00
  52#define I8254_COUNTER1_REG              0x01
  53#define I8254_COUNTER2_REG              0x02
  54#define I8254_CTRL_REG                  0x03
  55#define I8254_CTRL_SEL_CTR(x)           ((x) << 6)
  56#define I8254_CTRL_READBACK(x)          (I8254_CTRL_SEL_CTR(3) | BIT(x))
  57#define I8254_CTRL_READBACK_COUNT       I8254_CTRL_READBACK(4)
  58#define I8254_CTRL_READBACK_STATUS      I8254_CTRL_READBACK(5)
  59#define I8254_CTRL_READBACK_SEL_CTR(x)  (2 << (x))
  60#define I8254_CTRL_RW(x)                (((x) & 0x3) << 4)
  61#define I8254_CTRL_LATCH                I8254_CTRL_RW(0)
  62#define I8254_CTRL_LSB_ONLY             I8254_CTRL_RW(1)
  63#define I8254_CTRL_MSB_ONLY             I8254_CTRL_RW(2)
  64#define I8254_CTRL_LSB_MSB              I8254_CTRL_RW(3)
  65
  66/* counter maps zero to 0x10000 */
  67#define I8254_MAX_COUNT                 0x10000
  68
  69/**
  70 * struct comedi_8254 - private data used by this module
  71 * @iobase:             PIO base address of the registers (in/out)
  72 * @mmio:               MMIO base address of the registers (read/write)
  73 * @iosize:             I/O size used to access the registers (b/w/l)
  74 * @regshift:           register gap shift
  75 * @osc_base:           cascaded oscillator speed in ns
  76 * @divisor:            divisor for single counter
  77 * @divisor1:           divisor loaded into first cascaded counter
  78 * @divisor2:           divisor loaded into second cascaded counter
  79 * #next_div:           next divisor for single counter
  80 * @next_div1:          next divisor to use for first cascaded counter
  81 * @next_div2:          next divisor to use for second cascaded counter
  82 * @clock_src;          current clock source for each counter (driver specific)
  83 * @gate_src;           current gate source  for each counter (driver specific)
  84 * @busy:               flags used to indicate that a counter is "busy"
  85 * @insn_config:        driver specific (*insn_config) callback
  86 */
  87struct comedi_8254 {
  88        unsigned long iobase;
  89        void __iomem *mmio;
  90        unsigned int iosize;
  91        unsigned int regshift;
  92        unsigned int osc_base;
  93        unsigned int divisor;
  94        unsigned int divisor1;
  95        unsigned int divisor2;
  96        unsigned int next_div;
  97        unsigned int next_div1;
  98        unsigned int next_div2;
  99        unsigned int clock_src[3];
 100        unsigned int gate_src[3];
 101        bool busy[3];
 102
 103        int (*insn_config)(struct comedi_device *dev,
 104                           struct comedi_subdevice *s,
 105                           struct comedi_insn *insn, unsigned int *data);
 106};
 107
 108unsigned int comedi_8254_status(struct comedi_8254 *i8254,
 109                                unsigned int counter);
 110unsigned int comedi_8254_read(struct comedi_8254 *i8254, unsigned int counter);
 111void comedi_8254_write(struct comedi_8254 *i8254,
 112                       unsigned int counter, unsigned int val);
 113
 114int comedi_8254_set_mode(struct comedi_8254 *i8254,
 115                         unsigned int counter, unsigned int mode);
 116int comedi_8254_load(struct comedi_8254 *i8254,
 117                     unsigned int counter, unsigned int val, unsigned int mode);
 118
 119void comedi_8254_pacer_enable(struct comedi_8254 *i8254,
 120                              unsigned int counter1, unsigned int counter2,
 121                              bool enable);
 122void comedi_8254_update_divisors(struct comedi_8254 *i8254);
 123void comedi_8254_cascade_ns_to_timer(struct comedi_8254 *i8254,
 124                                     unsigned int *nanosec, unsigned int flags);
 125void comedi_8254_ns_to_timer(struct comedi_8254 *i8254,
 126                             unsigned int *nanosec, unsigned int flags);
 127
 128void comedi_8254_set_busy(struct comedi_8254 *i8254,
 129                          unsigned int counter, bool busy);
 130
 131void comedi_8254_subdevice_init(struct comedi_subdevice *s,
 132                                struct comedi_8254 *i8254);
 133
 134struct comedi_8254 *comedi_8254_init(unsigned long iobase,
 135                                     unsigned int osc_base,
 136                                     unsigned int iosize,
 137                                     unsigned int regshift);
 138struct comedi_8254 *comedi_8254_mm_init(void __iomem *mmio,
 139                                        unsigned int osc_base,
 140                                        unsigned int iosize,
 141                                        unsigned int regshift);
 142
 143#endif  /* _COMEDI_8254_H */
 144