| /* dv-m68hc11spi.c -- Simulation of the 68HC11 SPI |
| Copyright (C) 2000-2015 Free Software Foundation, Inc. |
| Written by Stephane Carrez (stcarrez@nerim.fr) |
| (From a driver model Contributed by Cygnus Solutions.) |
| |
| This file is part of the program GDB, the GNU debugger. |
| |
| 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/>. |
| |
| */ |
| |
| |
| #include "sim-main.h" |
| #include "hw-main.h" |
| #include "dv-sockser.h" |
| #include "sim-assert.h" |
| |
| |
| /* DEVICE |
| |
| m68hc11spi - m68hc11 SPI interface |
| |
| |
| DESCRIPTION |
| |
| Implements the m68hc11 Synchronous Serial Peripheral Interface |
| described in the m68hc11 user guide (Chapter 8 in pink book). |
| The SPI I/O controller is directly connected to the CPU |
| interrupt. The simulator implements: |
| |
| - SPI clock emulation |
| - Data transfer |
| - Write collision detection |
| |
| |
| PROPERTIES |
| |
| None |
| |
| |
| PORTS |
| |
| reset (input) |
| |
| Reset port. This port is only used to simulate a reset of the SPI |
| I/O controller. It should be connected to the RESET output of the cpu. |
| |
| */ |
| |
| |
| |
| /* port ID's */ |
| |
| enum |
| { |
| RESET_PORT |
| }; |
| |
| |
| static const struct hw_port_descriptor m68hc11spi_ports[] = |
| { |
| { "reset", RESET_PORT, 0, input_port, }, |
| { NULL, }, |
| }; |
| |
| |
| /* SPI */ |
| struct m68hc11spi |
| { |
| /* Information about next character to be transmited. */ |
| unsigned char tx_char; |
| int tx_bit; |
| unsigned char mode; |
| |
| unsigned char rx_char; |
| unsigned char rx_clear_scsr; |
| unsigned char clk_pin; |
| |
| /* SPI clock rate (twice the real clock). */ |
| unsigned int clock; |
| |
| /* Periodic SPI event. */ |
| struct hw_event* spi_event; |
| }; |
| |
| |
| |
| /* Finish off the partially created hw device. Attach our local |
| callbacks. Wire up our port names etc */ |
| |
| static hw_io_read_buffer_method m68hc11spi_io_read_buffer; |
| static hw_io_write_buffer_method m68hc11spi_io_write_buffer; |
| static hw_port_event_method m68hc11spi_port_event; |
| static hw_ioctl_method m68hc11spi_ioctl; |
| |
| #define M6811_SPI_FIRST_REG (M6811_SPCR) |
| #define M6811_SPI_LAST_REG (M6811_SPDR) |
| |
| |
| static void |
| attach_m68hc11spi_regs (struct hw *me, |
| struct m68hc11spi *controller) |
| { |
| hw_attach_address (hw_parent (me), M6811_IO_LEVEL, io_map, |
| M6811_SPI_FIRST_REG, |
| M6811_SPI_LAST_REG - M6811_SPI_FIRST_REG + 1, |
| me); |
| } |
| |
| static void |
| m68hc11spi_finish (struct hw *me) |
| { |
| struct m68hc11spi *controller; |
| |
| controller = HW_ZALLOC (me, struct m68hc11spi); |
| set_hw_data (me, controller); |
| set_hw_io_read_buffer (me, m68hc11spi_io_read_buffer); |
| set_hw_io_write_buffer (me, m68hc11spi_io_write_buffer); |
| set_hw_ports (me, m68hc11spi_ports); |
| set_hw_port_event (me, m68hc11spi_port_event); |
| #ifdef set_hw_ioctl |
| set_hw_ioctl (me, m68hc11spi_ioctl); |
| #else |
| me->to_ioctl = m68hc11spi_ioctl; |
| #endif |
| |
| /* Attach ourself to our parent bus. */ |
| attach_m68hc11spi_regs (me, controller); |
| |
| /* Initialize to reset state. */ |
| controller->spi_event = NULL; |
| controller->rx_clear_scsr = 0; |
| } |
| |
| |
| |
| /* An event arrives on an interrupt port */ |
| |
| static void |
| m68hc11spi_port_event (struct hw *me, |
| int my_port, |
| struct hw *source, |
| int source_port, |
| int level) |
| { |
| SIM_DESC sd; |
| struct m68hc11spi *controller; |
| sim_cpu* cpu; |
| unsigned8 val; |
| |
| controller = hw_data (me); |
| sd = hw_system (me); |
| cpu = STATE_CPU (sd, 0); |
| switch (my_port) |
| { |
| case RESET_PORT: |
| { |
| HW_TRACE ((me, "SPI reset")); |
| |
| /* Reset the state of SPI registers. */ |
| controller->rx_clear_scsr = 0; |
| if (controller->spi_event) |
| { |
| hw_event_queue_deschedule (me, controller->spi_event); |
| controller->spi_event = 0; |
| } |
| |
| val = 0; |
| m68hc11spi_io_write_buffer (me, &val, io_map, |
| (unsigned_word) M6811_SPCR, 1); |
| break; |
| } |
| |
| default: |
| hw_abort (me, "Event on unknown port %d", my_port); |
| break; |
| } |
| } |
| |
| static void |
| set_bit_port (struct hw *me, sim_cpu *cpu, int port, int mask, int value) |
| { |
| uint8 val; |
| |
| if (value) |
| val = cpu->ios[port] | mask; |
| else |
| val = cpu->ios[port] & ~mask; |
| |
| /* Set the new value and post an event to inform other devices |
| that pin 'port' changed. */ |
| m68hc11cpu_set_port (me, cpu, port, val); |
| } |
| |
| |
| /* When a character is sent/received by the SPI, the PD2..PD5 line |
| are driven by the following signals: |
| |
| B7 B6 |
| -----+---------+--------+---/-+------- |
| MOSI | | | | | | |
| MISO +---------+--------+---/-+ |
| ____ ___ |
| CLK _______/ \____/ \__ CPOL=0, CPHA=0 |
| _______ ____ __ |
| \____/ \___/ CPOL=1, CPHA=0 |
| ____ ____ __ |
| __/ \____/ \___/ CPOL=0, CPHA=1 |
| __ ____ ___ |
| \____/ \____/ \__ CPOL=1, CPHA=1 |
| |
| SS ___ ____ |
| \__________________________//___/ |
| |
| MISO = PD2 |
| MOSI = PD3 |
| SCK = PD4 |
| SS = PD5 |
| |
| */ |
| |
| #define SPI_START_BYTE 0 |
| #define SPI_START_BIT 1 |
| #define SPI_MIDDLE_BIT 2 |
| |
| void |
| m68hc11spi_clock (struct hw *me, void *data) |
| { |
| SIM_DESC sd; |
| struct m68hc11spi* controller; |
| sim_cpu *cpu; |
| int check_interrupt = 0; |
| |
| controller = hw_data (me); |
| sd = hw_system (me); |
| cpu = STATE_CPU (sd, 0); |
| |
| /* Cleanup current event. */ |
| if (controller->spi_event) |
| { |
| hw_event_queue_deschedule (me, controller->spi_event); |
| controller->spi_event = 0; |
| } |
| |
| /* Change a bit of data at each two SPI event. */ |
| if (controller->mode == SPI_START_BIT) |
| { |
| /* Reflect the bit value on bit 2 of port D. */ |
| set_bit_port (me, cpu, M6811_PORTD, (1 << 2), |
| (controller->tx_char & (1 << controller->tx_bit))); |
| controller->tx_bit--; |
| controller->mode = SPI_MIDDLE_BIT; |
| } |
| else if (controller->mode == SPI_MIDDLE_BIT) |
| { |
| controller->mode = SPI_START_BIT; |
| } |
| |
| if (controller->mode == SPI_START_BYTE) |
| { |
| /* Start a new SPI transfer. */ |
| |
| /* TBD: clear SS output. */ |
| controller->mode = SPI_START_BIT; |
| controller->tx_bit = 7; |
| set_bit_port (me, cpu, M6811_PORTD, (1 << 4), ~controller->clk_pin); |
| } |
| else |
| { |
| /* Change the SPI clock at each event on bit 4 of port D. */ |
| controller->clk_pin = ~controller->clk_pin; |
| set_bit_port (me, cpu, M6811_PORTD, (1 << 4), controller->clk_pin); |
| } |
| |
| /* Transmit is now complete for this byte. */ |
| if (controller->mode == SPI_START_BIT && controller->tx_bit < 0) |
| { |
| controller->rx_clear_scsr = 0; |
| cpu->ios[M6811_SPSR] |= M6811_SPIF; |
| if (cpu->ios[M6811_SPCR] & M6811_SPIE) |
| check_interrupt = 1; |
| } |
| else |
| { |
| controller->spi_event = hw_event_queue_schedule (me, controller->clock, |
| m68hc11spi_clock, |
| NULL); |
| } |
| |
| if (check_interrupt) |
| interrupts_update_pending (&cpu->cpu_interrupts); |
| } |
| |
| /* Flags of the SPCR register. */ |
| io_reg_desc spcr_desc[] = { |
| { M6811_SPIE, "SPIE ", "Serial Peripheral Interrupt Enable" }, |
| { M6811_SPE, "SPE ", "Serial Peripheral System Enable" }, |
| { M6811_DWOM, "DWOM ", "Port D Wire-OR mode option" }, |
| { M6811_MSTR, "MSTR ", "Master Mode Select" }, |
| { M6811_CPOL, "CPOL ", "Clock Polarity" }, |
| { M6811_CPHA, "CPHA ", "Clock Phase" }, |
| { M6811_SPR1, "SPR1 ", "SPI Clock Rate Select" }, |
| { M6811_SPR0, "SPR0 ", "SPI Clock Rate Select" }, |
| { 0, 0, 0 } |
| }; |
| |
| |
| /* Flags of the SPSR register. */ |
| io_reg_desc spsr_desc[] = { |
| { M6811_SPIF, "SPIF ", "SPI Transfer Complete flag" }, |
| { M6811_WCOL, "WCOL ", "Write Collision" }, |
| { M6811_MODF, "MODF ", "Mode Fault" }, |
| { 0, 0, 0 } |
| }; |
| |
| static void |
| m68hc11spi_info (struct hw *me) |
| { |
| SIM_DESC sd; |
| uint16 base = 0; |
| sim_cpu *cpu; |
| struct m68hc11spi *controller; |
| uint8 val; |
| |
| sd = hw_system (me); |
| cpu = STATE_CPU (sd, 0); |
| controller = hw_data (me); |
| |
| sim_io_printf (sd, "M68HC11 SPI:\n"); |
| |
| base = cpu_get_io_base (cpu); |
| |
| val = cpu->ios[M6811_SPCR]; |
| print_io_byte (sd, "SPCR", spcr_desc, val, base + M6811_SPCR); |
| sim_io_printf (sd, "\n"); |
| |
| val = cpu->ios[M6811_SPSR]; |
| print_io_byte (sd, "SPSR", spsr_desc, val, base + M6811_SPSR); |
| sim_io_printf (sd, "\n"); |
| |
| if (controller->spi_event) |
| { |
| signed64 t; |
| |
| sim_io_printf (sd, " SPI has %d bits to send\n", |
| controller->tx_bit + 1); |
| t = hw_event_remain_time (me, controller->spi_event); |
| sim_io_printf (sd, " SPI current bit-cycle finished in %s\n", |
| cycle_to_string (cpu, t, PRINT_TIME | PRINT_CYCLE)); |
| |
| t += (controller->tx_bit + 1) * 2 * controller->clock; |
| sim_io_printf (sd, " SPI operation finished in %s\n", |
| cycle_to_string (cpu, t, PRINT_TIME | PRINT_CYCLE)); |
| } |
| } |
| |
| static int |
| m68hc11spi_ioctl (struct hw *me, |
| hw_ioctl_request request, |
| va_list ap) |
| { |
| m68hc11spi_info (me); |
| return 0; |
| } |
| |
| /* generic read/write */ |
| |
| static unsigned |
| m68hc11spi_io_read_buffer (struct hw *me, |
| void *dest, |
| int space, |
| unsigned_word base, |
| unsigned nr_bytes) |
| { |
| SIM_DESC sd; |
| struct m68hc11spi *controller; |
| sim_cpu *cpu; |
| unsigned8 val; |
| |
| HW_TRACE ((me, "read 0x%08lx %d", (long) base, (int) nr_bytes)); |
| |
| sd = hw_system (me); |
| cpu = STATE_CPU (sd, 0); |
| controller = hw_data (me); |
| |
| switch (base) |
| { |
| case M6811_SPSR: |
| controller->rx_clear_scsr = cpu->ios[M6811_SCSR] |
| & (M6811_SPIF | M6811_WCOL | M6811_MODF); |
| |
| case M6811_SPCR: |
| val = cpu->ios[base]; |
| break; |
| |
| case M6811_SPDR: |
| if (controller->rx_clear_scsr) |
| { |
| cpu->ios[M6811_SPSR] &= ~controller->rx_clear_scsr; |
| controller->rx_clear_scsr = 0; |
| interrupts_update_pending (&cpu->cpu_interrupts); |
| } |
| val = controller->rx_char; |
| break; |
| |
| default: |
| return 0; |
| } |
| *((unsigned8*) dest) = val; |
| return 1; |
| } |
| |
| static unsigned |
| m68hc11spi_io_write_buffer (struct hw *me, |
| const void *source, |
| int space, |
| unsigned_word base, |
| unsigned nr_bytes) |
| { |
| SIM_DESC sd; |
| struct m68hc11spi *controller; |
| sim_cpu *cpu; |
| unsigned8 val; |
| |
| HW_TRACE ((me, "write 0x%08lx %d", (long) base, (int) nr_bytes)); |
| |
| sd = hw_system (me); |
| cpu = STATE_CPU (sd, 0); |
| controller = hw_data (me); |
| |
| val = *((const unsigned8*) source); |
| switch (base) |
| { |
| case M6811_SPCR: |
| cpu->ios[M6811_SPCR] = val; |
| |
| /* The SPI clock rate is 2, 4, 16, 32 of the internal CPU clock. |
| We have to drive the clock pin and need a 2x faster clock. */ |
| switch (val & (M6811_SPR1 | M6811_SPR0)) |
| { |
| case 0: |
| controller->clock = 1; |
| break; |
| |
| case 1: |
| controller->clock = 2; |
| break; |
| |
| case 2: |
| controller->clock = 8; |
| break; |
| |
| default: |
| controller->clock = 16; |
| break; |
| } |
| |
| /* Set the clock pin. */ |
| if ((val & M6811_CPOL) |
| && (controller->spi_event == 0 |
| || ((val & M6811_CPHA) && controller->mode == 1))) |
| controller->clk_pin = 1; |
| else |
| controller->clk_pin = 0; |
| |
| set_bit_port (me, cpu, M6811_PORTD, (1 << 4), controller->clk_pin); |
| break; |
| |
| /* Can't write to SPSR. */ |
| case M6811_SPSR: |
| break; |
| |
| case M6811_SPDR: |
| if (!(cpu->ios[M6811_SPCR] & M6811_SPE)) |
| { |
| return 0; |
| } |
| |
| if (controller->rx_clear_scsr) |
| { |
| cpu->ios[M6811_SPSR] &= ~controller->rx_clear_scsr; |
| controller->rx_clear_scsr = 0; |
| interrupts_update_pending (&cpu->cpu_interrupts); |
| } |
| |
| /* If transfer is taking place, a write to SPDR |
| generates a collision. */ |
| if (controller->spi_event) |
| { |
| cpu->ios[M6811_SPSR] |= M6811_WCOL; |
| break; |
| } |
| |
| /* Refuse the write if there was no read of SPSR. */ |
| /* ???? TBD. */ |
| |
| /* Prepare to send a byte. */ |
| controller->tx_char = val; |
| controller->mode = SPI_START_BYTE; |
| |
| /* Toggle clock pin internal value when CPHA is 0 so that |
| it will really change in the middle of a bit. */ |
| if (!(cpu->ios[M6811_SPCR] & M6811_CPHA)) |
| controller->clk_pin = ~controller->clk_pin; |
| |
| cpu->ios[M6811_SPDR] = val; |
| |
| /* Activate transmission. */ |
| m68hc11spi_clock (me, NULL); |
| break; |
| |
| default: |
| return 0; |
| } |
| return nr_bytes; |
| } |
| |
| |
| const struct hw_descriptor dv_m68hc11spi_descriptor[] = { |
| { "m68hc11spi", m68hc11spi_finish }, |
| { "m68hc12spi", m68hc11spi_finish }, |
| { NULL }, |
| }; |
| |
