diff options
author | Vas Crabb <vas@vastheman.com> | 2018-07-07 02:40:29 +1000 |
---|---|---|
committer | Vas Crabb <vas@vastheman.com> | 2018-07-07 02:40:29 +1000 |
commit | c3fb11c2c98a5c28ece6a27093a0f9def350ac64 (patch) | |
tree | c68b38f05ed1d32358add721fda7f45e8803479f /src/mame/drivers/dmv.cpp | |
parent | 5d9e33b786d7ef452317439359f3cbd8cc920513 (diff) |
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/mame/drivers/dmv.cpp')
-rw-r--r-- | src/mame/drivers/dmv.cpp | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/src/mame/drivers/dmv.cpp b/src/mame/drivers/dmv.cpp index 01466c1edf4..28317f8ab69 100644 --- a/src/mame/drivers/dmv.cpp +++ b/src/mame/drivers/dmv.cpp @@ -806,20 +806,20 @@ MACHINE_CONFIG_START(dmv_state::dmv) MCFG_UPD7220_DISPLAY_PIXELS_CALLBACK_OWNER(dmv_state, hgdc_display_pixels) MCFG_UPD7220_DRAW_TEXT_CALLBACK_OWNER(dmv_state, hgdc_draw_text) - MCFG_DEVICE_ADD( "dma8237", AM9517A, XTAL(4'000'000) ) - MCFG_I8237_OUT_HREQ_CB(WRITELINE(*this, dmv_state, dma_hrq_changed)) - MCFG_I8237_OUT_EOP_CB(WRITELINE(*this, dmv_state, dmac_eop)) - MCFG_I8237_IN_MEMR_CB(READ8(*this, dmv_state, program_r)) - MCFG_I8237_OUT_MEMW_CB(WRITE8(*this, dmv_state, program_w)) - MCFG_I8237_IN_IOR_0_CB(LOGGER("Read DMA CH1")) - MCFG_I8237_OUT_IOW_0_CB(LOGGER("Write DMA CH1")) - MCFG_I8237_IN_IOR_1_CB(LOGGER("Read DMA CH2")) - MCFG_I8237_OUT_IOW_1_CB(LOGGER("Write DMA CH2")) - MCFG_I8237_IN_IOR_2_CB(READ8("upd7220", upd7220_device, dack_r)) - MCFG_I8237_OUT_IOW_2_CB(WRITE8("upd7220", upd7220_device, dack_w)) - MCFG_I8237_IN_IOR_3_CB(READ8("i8272", i8272a_device, mdma_r)) - MCFG_I8237_OUT_IOW_3_CB(WRITE8("i8272", i8272a_device, mdma_w)) - MCFG_I8237_OUT_DACK_3_CB(WRITELINE(*this, dmv_state, dmac_dack3)) + AM9517A(config, m_dmac, 4_MHz_XTAL); + m_dmac->out_hreq_callback().set(FUNC(dmv_state::dma_hrq_changed)); + m_dmac->out_eop_callback().set(FUNC(dmv_state::dmac_eop)); + m_dmac->in_memr_callback().set(FUNC(dmv_state::program_r)); + m_dmac->out_memw_callback().set(FUNC(dmv_state::program_w)); + m_dmac->in_ior_callback<0>().set_log("Read DMA CH1"); + m_dmac->out_iow_callback<0>().set_log("Write DMA CH1"); + m_dmac->in_ior_callback<1>().set_log("Read DMA CH2"); + m_dmac->out_iow_callback<1>().set_log("Write DMA CH2"); + m_dmac->in_ior_callback<2>().set(m_hgdc, FUNC(upd7220_device::dack_r)); + m_dmac->out_iow_callback<2>().set(m_hgdc, FUNC(upd7220_device::dack_w)); + m_dmac->in_ior_callback<3>().set(m_fdc, FUNC(i8272a_device::mdma_r)); + m_dmac->out_iow_callback<3>().set(m_fdc, FUNC(i8272a_device::mdma_w)); + m_dmac->out_dack_callback<3>().set(FUNC(dmv_state::dmac_dack3)); MCFG_I8272A_ADD( "i8272", true ) MCFG_UPD765_INTRQ_CALLBACK(WRITELINE(*this, dmv_state, fdc_irq)) |