diff options
| -rw-r--r-- | hw/gpio/pl061.c | 62 | ||||
| -rw-r--r-- | hw/gpio/trace-events | 2 |
2 files changed, 57 insertions, 7 deletions
diff --git a/hw/gpio/pl061.c b/hw/gpio/pl061.c index a3c1386221..9360c143ee 100644 --- a/hw/gpio/pl061.c +++ b/hw/gpio/pl061.c @@ -94,18 +94,68 @@ static const VMStateDescription vmstate_pl061 = { } }; +static uint8_t pl061_floating(PL061State *s) +{ + /* + * Return mask of bits which correspond to pins configured as inputs + * and which are floating (neither pulled up to 1 nor down to 0). + */ + uint8_t floating; + + if (s->id == pl061_id_luminary) { + /* + * If both PUR and PDR bits are clear, there is neither a pullup + * nor a pulldown in place, and the output truly floats. + */ + floating = ~(s->pur | s->pdr); + } else { + /* Assume outputs are pulled high. FIXME: this is board dependent. */ + floating = 0; + } + return floating & ~s->dir; +} + +static uint8_t pl061_pullups(PL061State *s) +{ + /* + * Return mask of bits which correspond to pins configured as inputs + * and which are pulled up to 1. + */ + uint8_t pullups; + + if (s->id == pl061_id_luminary) { + /* + * The Luminary variant of the PL061 has an extra registers which + * the guest can use to configure whether lines should be pullup + * or pulldown. + */ + pullups = s->pur; + } else { + /* Assume outputs are pulled high. FIXME: this is board dependent. */ + pullups = 0xff; + } + return pullups & ~s->dir; +} + static void pl061_update(PL061State *s) { uint8_t changed; uint8_t mask; uint8_t out; int i; - - trace_pl061_update(DEVICE(s)->canonical_path, s->dir, s->data); - - /* Outputs float high. */ - /* FIXME: This is board dependent. */ - out = (s->data & s->dir) | ~s->dir; + uint8_t pullups = pl061_pullups(s); + uint8_t floating = pl061_floating(s); + + trace_pl061_update(DEVICE(s)->canonical_path, s->dir, s->data, + pullups, floating); + + /* + * Pins configured as output are driven from the data register; + * otherwise if they're pulled up they're 1, and if they're floating + * then we give them the same value they had previously, so we don't + * report any change to the other end. + */ + out = (s->data & s->dir) | pullups | (s->old_out_data & floating); changed = s->old_out_data ^ out; if (changed) { s->old_out_data = out; diff --git a/hw/gpio/trace-events b/hw/gpio/trace-events index 442be9406f..eb5fb4701c 100644 --- a/hw/gpio/trace-events +++ b/hw/gpio/trace-events @@ -14,7 +14,7 @@ nrf51_gpio_set(int64_t line, int64_t value) "line %" PRIi64 " value %" PRIi64 nrf51_gpio_update_output_irq(int64_t line, int64_t value) "line %" PRIi64 " value %" PRIi64 # pl061.c -pl061_update(const char *id, uint32_t dir, uint32_t data) "%s GPIODIR 0x%x GPIODATA 0x%x" +pl061_update(const char *id, uint32_t dir, uint32_t data, uint32_t pullups, uint32_t floating) "%s GPIODIR 0x%x GPIODATA 0x%x pullups 0x%x floating 0x%x" pl061_set_output(const char *id, int gpio, int level) "%s setting output %d to %d" pl061_input_change(const char *id, int gpio, int level) "%s input %d changed to %d" pl061_update_istate(const char *id, uint32_t istate, uint32_t im, int level) "%s GPIORIS 0x%x GPIOIE 0x%x interrupt level %d" |