diff options
Diffstat (limited to 'hw/misc/mps2-scc.c')
| -rw-r--r-- | hw/misc/mps2-scc.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/hw/misc/mps2-scc.c b/hw/misc/mps2-scc.c new file mode 100644 index 0000000..cc58d26 --- /dev/null +++ b/hw/misc/mps2-scc.c @@ -0,0 +1,310 @@ +/* + * ARM MPS2 SCC emulation + * + * Copyright (c) 2017 Linaro Limited + * Written by Peter Maydell + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 or + * (at your option) any later version. + */ + +/* This is a model of the SCC (Serial Communication Controller) + * found in the FPGA images of MPS2 development boards. + * + * Documentation of it can be found in the MPS2 TRM: + * http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.100112_0100_03_en/index.html + * and also in the Application Notes documenting individual FPGA images. + */ + +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "qapi/error.h" +#include "trace.h" +#include "hw/sysbus.h" +#include "hw/registerfields.h" +#include "hw/misc/mps2-scc.h" + +REG32(CFG0, 0) +REG32(CFG1, 4) +REG32(CFG3, 0xc) +REG32(CFG4, 0x10) +REG32(CFGDATA_RTN, 0xa0) +REG32(CFGDATA_OUT, 0xa4) +REG32(CFGCTRL, 0xa8) + FIELD(CFGCTRL, DEVICE, 0, 12) + FIELD(CFGCTRL, RES1, 12, 8) + FIELD(CFGCTRL, FUNCTION, 20, 6) + FIELD(CFGCTRL, RES2, 26, 4) + FIELD(CFGCTRL, WRITE, 30, 1) + FIELD(CFGCTRL, START, 31, 1) +REG32(CFGSTAT, 0xac) + FIELD(CFGSTAT, DONE, 0, 1) + FIELD(CFGSTAT, ERROR, 1, 1) +REG32(DLL, 0x100) +REG32(AID, 0xFF8) +REG32(ID, 0xFFC) + +/* Handle a write via the SYS_CFG channel to the specified function/device. + * Return false on error (reported to guest via SYS_CFGCTRL ERROR bit). + */ +static bool scc_cfg_write(MPS2SCC *s, unsigned function, + unsigned device, uint32_t value) +{ + trace_mps2_scc_cfg_write(function, device, value); + + if (function != 1 || device >= NUM_OSCCLK) { + qemu_log_mask(LOG_GUEST_ERROR, + "MPS2 SCC config write: bad function %d device %d\n", + function, device); + return false; + } + + s->oscclk[device] = value; + return true; +} + +/* Handle a read via the SYS_CFG channel to the specified function/device. + * Return false on error (reported to guest via SYS_CFGCTRL ERROR bit), + * or set *value on success. + */ +static bool scc_cfg_read(MPS2SCC *s, unsigned function, + unsigned device, uint32_t *value) +{ + if (function != 1 || device >= NUM_OSCCLK) { + qemu_log_mask(LOG_GUEST_ERROR, + "MPS2 SCC config read: bad function %d device %d\n", + function, device); + return false; + } + + *value = s->oscclk[device]; + + trace_mps2_scc_cfg_read(function, device, *value); + return true; +} + +static uint64_t mps2_scc_read(void *opaque, hwaddr offset, unsigned size) +{ + MPS2SCC *s = MPS2_SCC(opaque); + uint64_t r; + + switch (offset) { + case A_CFG0: + r = s->cfg0; + break; + case A_CFG1: + r = s->cfg1; + break; + case A_CFG3: + /* These are user-settable DIP switches on the board. We don't + * model that, so just return zeroes. + */ + r = 0; + break; + case A_CFG4: + r = s->cfg4; + break; + case A_CFGDATA_RTN: + r = s->cfgdata_rtn; + break; + case A_CFGDATA_OUT: + r = s->cfgdata_out; + break; + case A_CFGCTRL: + r = s->cfgctrl; + break; + case A_CFGSTAT: + r = s->cfgstat; + break; + case A_DLL: + r = s->dll; + break; + case A_AID: + r = s->aid; + break; + case A_ID: + r = s->id; + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "MPS2 SCC read: bad offset %x\n", (int) offset); + r = 0; + break; + } + + trace_mps2_scc_read(offset, r, size); + return r; +} + +static void mps2_scc_write(void *opaque, hwaddr offset, uint64_t value, + unsigned size) +{ + MPS2SCC *s = MPS2_SCC(opaque); + + trace_mps2_scc_write(offset, value, size); + + switch (offset) { + case A_CFG0: + /* TODO on some boards bit 0 controls RAM remapping */ + s->cfg0 = value; + break; + case A_CFG1: + /* CFG1 bits [7:0] control the board LEDs. We don't currently have + * a mechanism for displaying this graphically, so use a trace event. + */ + trace_mps2_scc_leds(value & 0x80 ? '*' : '.', + value & 0x40 ? '*' : '.', + value & 0x20 ? '*' : '.', + value & 0x10 ? '*' : '.', + value & 0x08 ? '*' : '.', + value & 0x04 ? '*' : '.', + value & 0x02 ? '*' : '.', + value & 0x01 ? '*' : '.'); + s->cfg1 = value; + break; + case A_CFGDATA_OUT: + s->cfgdata_out = value; + break; + case A_CFGCTRL: + /* Writing to CFGCTRL clears SYS_CFGSTAT */ + s->cfgstat = 0; + s->cfgctrl = value & ~(R_CFGCTRL_RES1_MASK | + R_CFGCTRL_RES2_MASK | + R_CFGCTRL_START_MASK); + + if (value & R_CFGCTRL_START_MASK) { + /* Start bit set -- do a read or write (instantaneously) */ + int device = extract32(s->cfgctrl, R_CFGCTRL_DEVICE_SHIFT, + R_CFGCTRL_DEVICE_LENGTH); + int function = extract32(s->cfgctrl, R_CFGCTRL_FUNCTION_SHIFT, + R_CFGCTRL_FUNCTION_LENGTH); + + s->cfgstat = R_CFGSTAT_DONE_MASK; + if (s->cfgctrl & R_CFGCTRL_WRITE_MASK) { + if (!scc_cfg_write(s, function, device, s->cfgdata_out)) { + s->cfgstat |= R_CFGSTAT_ERROR_MASK; + } + } else { + uint32_t result; + if (!scc_cfg_read(s, function, device, &result)) { + s->cfgstat |= R_CFGSTAT_ERROR_MASK; + } else { + s->cfgdata_rtn = result; + } + } + } + break; + case A_DLL: + /* DLL stands for Digital Locked Loop. + * Bits [31:24] (DLL_LOCK_MASK) are writable, and indicate a + * mask of which of the DLL_LOCKED bits [16:23] should be ORed + * together to determine the ALL_UNMASKED_DLLS_LOCKED bit [0]. + * For QEMU, our DLLs are always locked, so we can leave bit 0 + * as 1 always and don't need to recalculate it. + */ + s->dll = deposit32(s->dll, 24, 8, extract32(value, 24, 8)); + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "MPS2 SCC write: bad offset 0x%x\n", (int) offset); + break; + } +} + +static const MemoryRegionOps mps2_scc_ops = { + .read = mps2_scc_read, + .write = mps2_scc_write, + .endianness = DEVICE_LITTLE_ENDIAN, +}; + +static void mps2_scc_reset(DeviceState *dev) +{ + MPS2SCC *s = MPS2_SCC(dev); + int i; + + trace_mps2_scc_reset(); + s->cfg0 = 0; + s->cfg1 = 0; + s->cfgdata_rtn = 0; + s->cfgdata_out = 0; + s->cfgctrl = 0x100000; + s->cfgstat = 0; + s->dll = 0xffff0001; + for (i = 0; i < NUM_OSCCLK; i++) { + s->oscclk[i] = s->oscclk_reset[i]; + } +} + +static void mps2_scc_init(Object *obj) +{ + SysBusDevice *sbd = SYS_BUS_DEVICE(obj); + MPS2SCC *s = MPS2_SCC(obj); + + memory_region_init_io(&s->iomem, obj, &mps2_scc_ops, s, "mps2-scc", 0x1000); + sysbus_init_mmio(sbd, &s->iomem); +} + +static void mps2_scc_realize(DeviceState *dev, Error **errp) +{ +} + +static const VMStateDescription mps2_scc_vmstate = { + .name = "mps2-scc", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32(cfg0, MPS2SCC), + VMSTATE_UINT32(cfg1, MPS2SCC), + VMSTATE_UINT32(cfgdata_rtn, MPS2SCC), + VMSTATE_UINT32(cfgdata_out, MPS2SCC), + VMSTATE_UINT32(cfgctrl, MPS2SCC), + VMSTATE_UINT32(cfgstat, MPS2SCC), + VMSTATE_UINT32(dll, MPS2SCC), + VMSTATE_UINT32_ARRAY(oscclk, MPS2SCC, NUM_OSCCLK), + VMSTATE_END_OF_LIST() + } +}; + +static Property mps2_scc_properties[] = { + /* Values for various read-only ID registers (which are specific + * to the board model or FPGA image) + */ + DEFINE_PROP_UINT32("scc-cfg4", MPS2SCC, aid, 0), + DEFINE_PROP_UINT32("scc-aid", MPS2SCC, aid, 0), + DEFINE_PROP_UINT32("scc-id", MPS2SCC, aid, 0), + /* These are the initial settings for the source clocks on the board. + * In hardware they can be configured via a config file read by the + * motherboard configuration controller to suit the FPGA image. + * These default values are used by most of the standard FPGA images. + */ + DEFINE_PROP_UINT32("oscclk0", MPS2SCC, oscclk_reset[0], 50000000), + DEFINE_PROP_UINT32("oscclk1", MPS2SCC, oscclk_reset[1], 24576000), + DEFINE_PROP_UINT32("oscclk2", MPS2SCC, oscclk_reset[2], 25000000), + DEFINE_PROP_END_OF_LIST(), +}; + +static void mps2_scc_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = mps2_scc_realize; + dc->vmsd = &mps2_scc_vmstate; + dc->reset = mps2_scc_reset; + dc->props = mps2_scc_properties; +} + +static const TypeInfo mps2_scc_info = { + .name = TYPE_MPS2_SCC, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(MPS2SCC), + .instance_init = mps2_scc_init, + .class_init = mps2_scc_class_init, +}; + +static void mps2_scc_register_types(void) +{ + type_register_static(&mps2_scc_info); +} + +type_init(mps2_scc_register_types); |