Commit 4aa5d285 authored by Jan Kiszka's avatar Jan Kiszka Committed by Anthony Liguori
Browse files

i8254: Factor out pit_get_channel_info 



Instead of providing 4 individual query functions for mode, gate, output
and initial counter state, introduce a service that queries all
information at once. This comes with tiny additional costs for
pcspk_callback but with a much cleaner interface. Also, it will simplify
the implementation of the KVM in-kernel PIT model.

Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent 302fe51b

hw/i8254.c

+10 −25
Original line number Diff line number Diff line
@@ -90,7 +90,7 @@ static int pit_get_count(PITChannelState *s) 
}



/* get pit output bit */

static int pit_get_out1(PITChannelState *s, int64_t current_time)

static int pit_get_out(PITChannelState *s, int64_t current_time)

{

    uint64_t d;

    int out;
@@ -122,13 +122,6 @@ static int pit_get_out1(PITChannelState *s, int64_t current_time) 
    return out;

}



int pit_get_out(ISADevice *dev, int channel, int64_t current_time)

{

    PITState *pit = DO_UPCAST(PITState, dev, dev);

    PITChannelState *s = &pit->channels[channel];

    return pit_get_out1(s, current_time);

}



/* return -1 if no transition will occur.  */

static int64_t pit_get_next_transition_time(PITChannelState *s,

                                            int64_t current_time)
@@ -215,25 +208,15 @@ void pit_set_gate(ISADevice *dev, int channel, int val) 
    s->gate = val;

}



int pit_get_gate(ISADevice *dev, int channel)

{

    PITState *pit = DO_UPCAST(PITState, dev, dev);

    PITChannelState *s = &pit->channels[channel];

    return s->gate;

}



int pit_get_initial_count(ISADevice *dev, int channel)

void pit_get_channel_info(ISADevice *dev, int channel, PITChannelInfo *info)

{

    PITState *pit = DO_UPCAST(PITState, dev, dev);

    PITChannelState *s = &pit->channels[channel];

    return s->count;

}



int pit_get_mode(ISADevice *dev, int channel)

{

    PITState *pit = DO_UPCAST(PITState, dev, dev);

    PITChannelState *s = &pit->channels[channel];

    return s->mode;

    info->gate = s->gate;

    info->mode = s->mode;

    info->initial_count = s->count;

    info->out = pit_get_out(s, qemu_get_clock_ns(vm_clock));

}



static inline void pit_load_count(PITChannelState *s, int val)
@@ -274,7 +257,9 @@ static void pit_ioport_write(void *opaque, uint32_t addr, uint32_t val) 
                    if (!(val & 0x10) && !s->status_latched) {

                        /* status latch */

                        /* XXX: add BCD and null count */

                        s->status =  (pit_get_out1(s, qemu_get_clock_ns(vm_clock)) << 7) |

                        s->status =

                            (pit_get_out(s,

                                         qemu_get_clock_ns(vm_clock)) << 7) |

                            (s->rw_mode << 4) |

                            (s->mode << 1) |

                            s->bcd;
@@ -381,7 +366,7 @@ static void pit_irq_timer_update(PITChannelState *s, int64_t current_time) 
        return;

    }

    expire_time = pit_get_next_transition_time(s, current_time);

    irq_level = pit_get_out1(s, current_time);

    irq_level = pit_get_out(s, current_time);

    qemu_set_irq(s->irq, irq_level);

#ifdef DEBUG_PIT

    printf("irq_level=%d next_delay=%f\n",

hw/i8254.h

+8 −4
Original line number Diff line number Diff line
@@ -30,6 +30,13 @@ 


#define PIT_FREQ 1193182



typedef struct PITChannelInfo {

    int gate;

    int mode;

    int initial_count;

    int out;

} PITChannelInfo;



static inline ISADevice *pit_init(ISABus *bus, int base, int isa_irq,

                                  qemu_irq alt_irq)

{
@@ -45,9 +52,6 @@ static inline ISADevice *pit_init(ISABus *bus, int base, int isa_irq, 
}



void pit_set_gate(ISADevice *dev, int channel, int val);

int pit_get_gate(ISADevice *dev, int channel);

int pit_get_initial_count(ISADevice *dev, int channel);

int pit_get_mode(ISADevice *dev, int channel);

int pit_get_out(ISADevice *dev, int channel, int64_t current_time);

void pit_get_channel_info(ISADevice *dev, int channel, PITChannelInfo *info);



#endif /* !HW_I8254_H */

hw/pcspk.c

+11 −5
Original line number Diff line number Diff line
@@ -75,12 +75,16 @@ static inline void generate_samples(PCSpkState *s) 
static void pcspk_callback(void *opaque, int free)

{

    PCSpkState *s = opaque;

    PITChannelInfo ch;

    unsigned int n;



    if (pit_get_mode(s->pit, 2) != 3)

    pit_get_channel_info(s->pit, 2, &ch);



    if (ch.mode != 3) {

        return;

    }



    n = pit_get_initial_count(s->pit, 2);

    n = ch.initial_count;

    /* avoid frequencies that are not reproducible with sample rate */

    if (n < PCSPK_MIN_COUNT)

        n = 0;
@@ -121,12 +125,14 @@ static uint64_t pcspk_io_read(void *opaque, target_phys_addr_t addr, 
                              unsigned size)

{

    PCSpkState *s = opaque;

    int out;

    PITChannelInfo ch;



    pit_get_channel_info(s->pit, 2, &ch);



    s->dummy_refresh_clock ^= (1 << 4);

    out = pit_get_out(s->pit, 2, qemu_get_clock_ns(vm_clock)) << 5;



    return pit_get_gate(s->pit, 2) | (s->data_on << 1) | s->dummy_refresh_clock | out;

    return ch.gate | (s->data_on << 1) | s->dummy_refresh_clock |

       (ch.out << 5);

}



static void pcspk_io_write(void *opaque, target_phys_addr_t addr, uint64_t val,