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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
commitc3fb11c2c98a5c28ece6a27093a0f9def350ac64 (patch)
treec68b38f05ed1d32358add721fda7f45e8803479f /src/mame/drivers/dmv.cpp
parent5d9e33b786d7ef452317439359f3cbd8cc920513 (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.cpp28
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))