include/i8254.hpp

   1 #ifndef I8254_HPP
   2 #define I8254_HPP
   3
   4 #include "device.hpp"
   5 #include "io.hpp"
   6 #include "marshal.hpp"
   7 #include "timer.hpp"
   8
   9 #define PIT_FREQ 1193182
  10
  11 class PITChannel : public Device
  12 {
  13 public:
  14     PITChannel(void);
  15
  16     void write_back_command(uint8_t val);
  17     void write_access(uint8_t val);
  18     void write_state_val(uint8_t val);
  19     uint8_t read(void);
  20
  21     void marshal(Marshaller *m, const char *name);
  22     void reset(int gate);
  23
  24     OutputPin irq;
  25
  26 private:
  27     int64_t get_next_transition_time(uint64_t current_time);
  28     void irq_timer_update(uint64_t current_time);
  29     void on_irq_timer(void);
  30     int get_out1(int64_t current_time);
  31     void load_count(int val);
  32     void latch_count(void);
  33     uint16_t get_count(void);
  34     void update_irq(uint64_t current_time);
  35
  36     uint32_t count; /* can be 65536 */
  37     uint16_t latched_count;
  38     uint8_t count_latched;
  39     uint8_t status_latched;
  40     uint8_t status;
  41     uint8_t read_state;
  42     uint8_t write_state;
  43     uint8_t write_latch;
  44     uint8_t rw_mode;
  45     uint8_t mode;
  46     uint8_t bcd; /* not supported */
  47     uint8_t gate; /* timer start */
  48     int64_t count_load_time;
  49     /* irq handling */
  50     int64_t next_transition_time;
  51     Timer irq_timer;
  52 };
  53
  54 class PIT : public Device
  55 {
  56 public:
  57     void marshal(Marshaller *m, const char *name);
  58
  59     void write(uint8_t addr, uint8_t val);
  60     uint8_t read(uint8_t addr);
  61
  62     OutputPin &get_irq(void);
  63
  64     void reset(void);
  65
  66 private:
  67     PITChannel channels[3];
  68 };
  69
  70 #endif