summaryrefslogtreecommitdiffstats
path: root/src/devices/machine/z80sio.cpp
diff options
context:
space:
mode:
authorGravatarGravatar Vas Crabb <vas@vastheman.com>2018-07-07 02:40:29 +1000
committerGravatarGravatar Vas Crabb <vas@vastheman.com>2018-07-07 02:40:29 +1000
commitc3fb11c2c98a5c28ece6a27093a0f9def350ac64 (patch)
treec68b38f05ed1d32358add721fda7f45e8803479f /src/devices/machine/z80sio.cpp
parent5d9e33b786d7ef452317439359f3cbd8cc920513 (diff)
downloadmame-c3fb11c2c98a5c28ece6a27093a0f9def350ac64.tar.xz
mame-c3fb11c2c98a5c28ece6a27093a0f9def350ac64.zip
devcb3
There are multiple issues with the current device callbacks: * They always dispatch through a pointer-to-member * Chained callbacks are a linked list so the branch unit can't predict the early * There's a runtime decision made on the left/right shift direction * There are runtime NULL checks on various objects * Binding a lambda isn't practical * Arbitrary transformations are not supported * When chaining callbacks it isn't clear what the MCFG_DEVCB_ modifiers apply to * It isn't possible to just append to a callback in derived configuration * The macros need a magic, hidden local called devcb * Moving code that uses the magic locals around is error-prone * Writing the MCFG_ macros to make a device usable is a pain * You can't discover applicable MCFG_ macros with intellisense * Macros are not scoped * Using an inappropriate macro isn't detected at compile time * Lots of other things This changeset overcomes the biggest obstacle to remving MCFG_ macros altogether. Essentially, to allow a devcb to be configured, call .bind() and expose the result (a bind target for the callback). Bind target methods starting with "set" repace the current callbacks; methods starting with "append" append to them. You can't reconfigure a callback after resolving it. There's no need to use a macro matching the handler signatures - use FUNC for everything. Current device is implied if no tag/finder is supplied (no need for explicit this). Lambdas are supported, and the memory space and offset are optional. These kinds of things work: * .read_cb().set([this] () { return something; }); * .read_cb().set([this] (offs_t offset) { return ~offset; }); * .write_cb().set([this] (offs_t offset, u8 data) { m_array[offset] = data; }); * .write_cb().set([this] (int state) { some_var = state; }); Arbitrary transforms are allowed, and they can modify offset/mask for example: * .read_cb().set(FUNC(my_state::handler)).transform([] (u8 data) { return bitswap<4>(data, 1, 3, 0, 2); }); * .read_cb().set(m_dev, FUNC(some_device::member)).transform([] (offs_t &offset, u8 data) { offset ^= 3; return data; }); It's possible to stack arbitrary transforms, at the cost of compile time (the whole transform stack gets inlined at compile time). Shifts count as an arbitrary transform, but mask/exor does not. Order of mask/shift/exor now matters. Modifications are applied in the specified order. These are NOT EQUIVALENT: * .read_cb().set(FUNC(my_state::handler)).mask(0x06).lshift(2); * .read_cb().set(FUNC(my_state::handler)).lshift(2).mask(0x06); The bit helper no longer reverses its behaviour for read callbacks, and I/O ports are no longer aware of the field mask. Binding a read callback to no-op is not supported - specify a constant. The GND and VCC aliases have been removed intentionally - they're TTL-centric, and were already being abused. Other quirks have been preserved, including write logger only logging when the data is non-zero (quite unhelpful in many of the cases where it's used). Legacy syntax is still supported for simple cases, but will be phased out. New devices should not have MCFG_ macros. I don't think I've missed any fundamental issues, but if I've broken something, let me know.
Diffstat (limited to 'src/devices/machine/z80sio.cpp')
-rw-r--r--src/devices/machine/z80sio.cpp27
1 files changed, 17 insertions, 10 deletions
diff --git a/src/devices/machine/z80sio.cpp b/src/devices/machine/z80sio.cpp
index c52a29983b5..c190fb700a6 100644
--- a/src/devices/machine/z80sio.cpp
+++ b/src/devices/machine/z80sio.cpp
@@ -355,6 +355,7 @@ z80sio_device::z80sio_device(const machine_config &mconfig, device_type type, co
device_z80daisy_interface(mconfig, *this),
m_chanA(*this, CHANA_TAG),
m_chanB(*this, CHANB_TAG),
+ m_hostcpu(*this, finder_base::DUMMY_TAG),
m_out_txd_cb{ { *this }, { *this } },
m_out_dtr_cb{ { *this }, { *this } },
m_out_rts_cb{ { *this }, { *this } },
@@ -362,8 +363,7 @@ z80sio_device::z80sio_device(const machine_config &mconfig, device_type type, co
m_out_sync_cb{ { *this }, { *this } },
m_out_int_cb(*this),
m_out_rxdrq_cb{ { *this }, { *this } },
- m_out_txdrq_cb{ { *this }, { *this } },
- m_cputag(nullptr)
+ m_out_txdrq_cb{ { *this }, { *this } }
{
for (auto & elem : m_int_state)
elem = 0;
@@ -390,6 +390,15 @@ upd7201_new_device::upd7201_new_device(const machine_config &mconfig, const char
}
//-------------------------------------------------
+// device_validity_check - device-specific validation
+//-------------------------------------------------
+void z80sio_device::device_validity_check(validity_checker &valid) const
+{
+ if ((m_hostcpu.finder_tag() != finder_base::DUMMY_TAG) && !m_hostcpu)
+ osd_printf_error("Host CPU configured but not found.\n");
+}
+
+//-------------------------------------------------
// device_resolve_objects - device-specific setup
//-------------------------------------------------
void z80sio_device::device_resolve_objects()
@@ -487,12 +496,11 @@ int z80sio_device::z80daisy_irq_ack()
// Did we not find a vector? Get the notion of a default vector from the CPU implementation
logerror(" - failed to find an interrupt to ack!\n");
- if (m_cputag)
+ if (m_hostcpu)
{
// default irq vector is -1 for 68000 but 0 for z80 for example...
- // FIXME: use an optional_device or something
- int const ret = owner()->subdevice<cpu_device>(m_cputag)->default_irq_vector(INPUT_LINE_IRQ0);
- LOGINT(" - failed to find an interrupt to ack [%s], returning default IRQ vector: %02x\n", m_cputag, ret);
+ int const ret = m_hostcpu->default_irq_vector(INPUT_LINE_IRQ0);
+ LOGINT(" - failed to find an interrupt to ack [%s], returning default IRQ vector: %02x\n", m_hostcpu->tag(), ret);
return ret;
}
@@ -556,12 +564,11 @@ int i8274_new_device::z80daisy_irq_ack()
logerror(" - failed to find an interrupt to ack!\n");
}
- if (m_cputag)
+ if (m_hostcpu)
{
// default irq vector is -1 for 68000 but 0 for z80 for example...
- // FIXME: use an optional_device or something
- int const ret = owner()->subdevice<cpu_device>(m_cputag)->default_irq_vector(INPUT_LINE_IRQ0);
- LOGINT(" - failed to find an interrupt to ack [%s], returning default IRQ vector: %02x\n", m_cputag, ret);
+ int const ret = m_hostcpu->default_irq_vector(INPUT_LINE_IRQ0);
+ LOGINT(" - failed to find an interrupt to ack [%s], returning default IRQ vector: %02x\n", m_hostcpu->tag(), ret);
return ret;
}