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- /* Blackfin Universal Asynchronous Receiver/Transmitter (UART) model.
- For "old style" UARTs on BF53x/etc... parts.
- Copyright (C) 2010-2022 Free Software Foundation, Inc.
- Contributed by Analog Devices, Inc.
- This file is part of simulators.
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 3 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- /* This must come before any other includes. */
- #include "defs.h"
- #include "sim-main.h"
- #include "dv-sockser.h"
- #include "devices.h"
- #include "dv-bfin_uart.h"
- /* XXX: Should we bother emulating the TX/RX FIFOs ? */
- /* Internal state needs to be the same as bfin_uart2. */
- struct bfin_uart
- {
- /* This top portion matches common dv_bfin struct. */
- bu32 base;
- struct hw *dma_master;
- bool acked;
- struct hw_event *handler;
- char saved_byte;
- int saved_count;
- /* This is aliased to DLH. */
- bu16 ier;
- /* These are aliased to DLL. */
- bu16 thr, rbr;
- /* Order after here is important -- matches hardware MMR layout. */
- bu16 BFIN_MMR_16(dll);
- bu16 BFIN_MMR_16(dlh);
- bu16 BFIN_MMR_16(iir);
- bu16 BFIN_MMR_16(lcr);
- bu16 BFIN_MMR_16(mcr);
- bu16 BFIN_MMR_16(lsr);
- bu16 BFIN_MMR_16(msr);
- bu16 BFIN_MMR_16(scr);
- bu16 _pad0[2];
- bu16 BFIN_MMR_16(gctl);
- };
- #define mmr_base() offsetof(struct bfin_uart, dll)
- #define mmr_offset(mmr) (offsetof(struct bfin_uart, mmr) - mmr_base())
- static const char * const mmr_names[] =
- {
- "UART_RBR/UART_THR", "UART_IER", "UART_IIR", "UART_LCR", "UART_MCR",
- "UART_LSR", "UART_MSR", "UART_SCR", "<INV>", "UART_GCTL",
- };
- static const char *mmr_name (struct bfin_uart *uart, bu32 idx)
- {
- if (uart->lcr & DLAB)
- if (idx < 2)
- return idx == 0 ? "UART_DLL" : "UART_DLH";
- return mmr_names[idx];
- }
- #define mmr_name(off) mmr_name (uart, (off) / 4)
- static void
- bfin_uart_poll (struct hw *me, void *data)
- {
- struct bfin_uart *uart = data;
- bu16 lsr;
- uart->handler = NULL;
- lsr = bfin_uart_get_status (me);
- if (lsr & DR)
- hw_port_event (me, DV_PORT_RX, 1);
- bfin_uart_reschedule (me);
- }
- void
- bfin_uart_reschedule (struct hw *me)
- {
- struct bfin_uart *uart = hw_data (me);
- if (uart->ier & ERBFI)
- {
- if (!uart->handler)
- uart->handler = hw_event_queue_schedule (me, 10000,
- bfin_uart_poll, uart);
- }
- else
- {
- if (uart->handler)
- {
- hw_event_queue_deschedule (me, uart->handler);
- uart->handler = NULL;
- }
- }
- }
- bu16
- bfin_uart_write_byte (struct hw *me, bu16 thr, bu16 mcr)
- {
- struct bfin_uart *uart = hw_data (me);
- unsigned char ch = thr;
- if (mcr & LOOP_ENA)
- {
- /* XXX: This probably doesn't work exactly right with
- external FIFOs ... */
- uart->saved_byte = thr;
- uart->saved_count = 1;
- }
- bfin_uart_write_buffer (me, &ch, 1);
- return thr;
- }
- static unsigned
- bfin_uart_io_write_buffer (struct hw *me, const void *source,
- int space, address_word addr, unsigned nr_bytes)
- {
- struct bfin_uart *uart = hw_data (me);
- bu32 mmr_off;
- bu32 value;
- bu16 *valuep;
- /* Invalid access mode is higher priority than missing register. */
- if (!dv_bfin_mmr_require_16 (me, addr, nr_bytes, true))
- return 0;
- value = dv_load_2 (source);
- mmr_off = addr - uart->base;
- valuep = (void *)((uintptr_t)uart + mmr_base() + mmr_off);
- HW_TRACE_WRITE ();
- /* XXX: All MMRs are "8bit" ... what happens to high 8bits ? */
- switch (mmr_off)
- {
- case mmr_offset(dll):
- if (uart->lcr & DLAB)
- uart->dll = value;
- else
- {
- uart->thr = bfin_uart_write_byte (me, value, uart->mcr);
- if (uart->ier & ETBEI)
- hw_port_event (me, DV_PORT_TX, 1);
- }
- break;
- case mmr_offset(dlh):
- if (uart->lcr & DLAB)
- uart->dlh = value;
- else
- {
- uart->ier = value;
- bfin_uart_reschedule (me);
- }
- break;
- case mmr_offset(iir):
- case mmr_offset(lsr):
- /* XXX: Writes are ignored ? */
- break;
- case mmr_offset(lcr):
- case mmr_offset(mcr):
- case mmr_offset(scr):
- case mmr_offset(gctl):
- *valuep = value;
- break;
- default:
- dv_bfin_mmr_invalid (me, addr, nr_bytes, true);
- return 0;
- }
- return nr_bytes;
- }
- /* Switch between socket and stdin on the fly. */
- bu16
- bfin_uart_get_next_byte (struct hw *me, bu16 rbr, bu16 mcr, bool *fresh)
- {
- SIM_DESC sd = hw_system (me);
- struct bfin_uart *uart = hw_data (me);
- int status = dv_sockser_status (sd);
- bool _fresh;
- /* NB: The "uart" here may only use interal state. */
- if (!fresh)
- fresh = &_fresh;
- *fresh = false;
- if (uart->saved_count > 0)
- {
- *fresh = true;
- rbr = uart->saved_byte;
- --uart->saved_count;
- }
- else if (mcr & LOOP_ENA)
- {
- /* RX is disconnected, so only return local data. */
- }
- else if (status & DV_SOCKSER_DISCONNECTED)
- {
- char byte;
- int ret = sim_io_poll_read (sd, 0/*STDIN*/, &byte, 1);
- if (ret > 0)
- {
- *fresh = true;
- rbr = byte;
- }
- }
- else
- rbr = dv_sockser_read (sd);
- return rbr;
- }
- bu16
- bfin_uart_get_status (struct hw *me)
- {
- SIM_DESC sd = hw_system (me);
- struct bfin_uart *uart = hw_data (me);
- int status = dv_sockser_status (sd);
- bu16 lsr = 0;
- if (status & DV_SOCKSER_DISCONNECTED)
- {
- if (uart->saved_count <= 0)
- uart->saved_count = sim_io_poll_read (sd, 0/*STDIN*/,
- &uart->saved_byte, 1);
- lsr |= TEMT | THRE | (uart->saved_count > 0 ? DR : 0);
- }
- else
- lsr |= (status & DV_SOCKSER_INPUT_EMPTY ? 0 : DR) |
- (status & DV_SOCKSER_OUTPUT_EMPTY ? TEMT | THRE : 0);
- return lsr;
- }
- static unsigned
- bfin_uart_io_read_buffer (struct hw *me, void *dest,
- int space, address_word addr, unsigned nr_bytes)
- {
- struct bfin_uart *uart = hw_data (me);
- bu32 mmr_off;
- bu16 *valuep;
- /* Invalid access mode is higher priority than missing register. */
- if (!dv_bfin_mmr_require_16 (me, addr, nr_bytes, false))
- return 0;
- mmr_off = addr - uart->base;
- valuep = (void *)((uintptr_t)uart + mmr_base() + mmr_off);
- HW_TRACE_READ ();
- switch (mmr_off)
- {
- case mmr_offset(dll):
- if (uart->lcr & DLAB)
- dv_store_2 (dest, uart->dll);
- else
- {
- uart->rbr = bfin_uart_get_next_byte (me, uart->rbr, uart->mcr, NULL);
- dv_store_2 (dest, uart->rbr);
- }
- break;
- case mmr_offset(dlh):
- if (uart->lcr & DLAB)
- dv_store_2 (dest, uart->dlh);
- else
- dv_store_2 (dest, uart->ier);
- break;
- case mmr_offset(lsr):
- /* XXX: Reads are destructive on most parts, but not all ... */
- uart->lsr |= bfin_uart_get_status (me);
- dv_store_2 (dest, *valuep);
- uart->lsr = 0;
- break;
- case mmr_offset(iir):
- /* XXX: Reads are destructive ... */
- case mmr_offset(lcr):
- case mmr_offset(mcr):
- case mmr_offset(scr):
- case mmr_offset(gctl):
- dv_store_2 (dest, *valuep);
- break;
- default:
- dv_bfin_mmr_invalid (me, addr, nr_bytes, false);
- return 0;
- }
- return nr_bytes;
- }
- unsigned
- bfin_uart_read_buffer (struct hw *me, unsigned char *buffer, unsigned nr_bytes)
- {
- SIM_DESC sd = hw_system (me);
- struct bfin_uart *uart = hw_data (me);
- int status = dv_sockser_status (sd);
- unsigned i = 0;
- if (status & DV_SOCKSER_DISCONNECTED)
- {
- int ret;
- while (uart->saved_count > 0 && i < nr_bytes)
- {
- buffer[i++] = uart->saved_byte;
- --uart->saved_count;
- }
- ret = sim_io_poll_read (sd, 0/*STDIN*/, (char *) buffer, nr_bytes - i);
- if (ret > 0)
- i += ret;
- }
- else
- buffer[i++] = dv_sockser_read (sd);
- return i;
- }
- static unsigned
- bfin_uart_dma_read_buffer (struct hw *me, void *dest, int space,
- unsigned_word addr, unsigned nr_bytes)
- {
- HW_TRACE_DMA_READ ();
- return bfin_uart_read_buffer (me, dest, nr_bytes);
- }
- unsigned
- bfin_uart_write_buffer (struct hw *me, const unsigned char *buffer,
- unsigned nr_bytes)
- {
- SIM_DESC sd = hw_system (me);
- int status = dv_sockser_status (sd);
- if (status & DV_SOCKSER_DISCONNECTED)
- {
- sim_io_write_stdout (sd, (const char *) buffer, nr_bytes);
- sim_io_flush_stdout (sd);
- }
- else
- {
- /* Normalize errors to a value of 0. */
- int ret = dv_sockser_write_buffer (sd, buffer, nr_bytes);
- nr_bytes = CLAMP (ret, 0, nr_bytes);
- }
- return nr_bytes;
- }
- static unsigned
- bfin_uart_dma_write_buffer (struct hw *me, const void *source,
- int space, unsigned_word addr,
- unsigned nr_bytes,
- int violate_read_only_section)
- {
- struct bfin_uart *uart = hw_data (me);
- unsigned ret;
- HW_TRACE_DMA_WRITE ();
- ret = bfin_uart_write_buffer (me, source, nr_bytes);
- if (ret == nr_bytes && (uart->ier & ETBEI))
- hw_port_event (me, DV_PORT_TX, 1);
- return ret;
- }
- static const struct hw_port_descriptor bfin_uart_ports[] =
- {
- { "tx", DV_PORT_TX, 0, output_port, },
- { "rx", DV_PORT_RX, 0, output_port, },
- { "stat", DV_PORT_STAT, 0, output_port, },
- { NULL, 0, 0, 0, },
- };
- static void
- attach_bfin_uart_regs (struct hw *me, struct bfin_uart *uart)
- {
- address_word attach_address;
- int attach_space;
- unsigned attach_size;
- reg_property_spec reg;
- if (hw_find_property (me, "reg") == NULL)
- hw_abort (me, "Missing \"reg\" property");
- if (!hw_find_reg_array_property (me, "reg", 0, ®))
- hw_abort (me, "\"reg\" property must contain three addr/size entries");
- hw_unit_address_to_attach_address (hw_parent (me),
- ®.address,
- &attach_space, &attach_address, me);
- hw_unit_size_to_attach_size (hw_parent (me), ®.size, &attach_size, me);
- if (attach_size != BFIN_MMR_UART_SIZE)
- hw_abort (me, "\"reg\" size must be %#x", BFIN_MMR_UART_SIZE);
- hw_attach_address (hw_parent (me),
- 0, attach_space, attach_address, attach_size, me);
- uart->base = attach_address;
- }
- static void
- bfin_uart_finish (struct hw *me)
- {
- struct bfin_uart *uart;
- uart = HW_ZALLOC (me, struct bfin_uart);
- set_hw_data (me, uart);
- set_hw_io_read_buffer (me, bfin_uart_io_read_buffer);
- set_hw_io_write_buffer (me, bfin_uart_io_write_buffer);
- set_hw_dma_read_buffer (me, bfin_uart_dma_read_buffer);
- set_hw_dma_write_buffer (me, bfin_uart_dma_write_buffer);
- set_hw_ports (me, bfin_uart_ports);
- attach_bfin_uart_regs (me, uart);
- /* Initialize the UART. */
- uart->dll = 0x0001;
- uart->iir = 0x0001;
- uart->lsr = 0x0060;
- }
- const struct hw_descriptor dv_bfin_uart_descriptor[] =
- {
- {"bfin_uart", bfin_uart_finish,},
- {NULL, NULL},
- };
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