diff options
Diffstat (limited to 'c/src/lib/libbsp/m68k/gen68340/timer/timer.c')
| -rw-r--r-- | c/src/lib/libbsp/m68k/gen68340/timer/timer.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/m68k/gen68340/timer/timer.c b/c/src/lib/libbsp/m68k/gen68340/timer/timer.c new file mode 100644 index 0000000000..a2bc2186fb --- /dev/null +++ b/c/src/lib/libbsp/m68k/gen68340/timer/timer.c @@ -0,0 +1,287 @@ +/* + * Timer_init() + * + * ATTENTION: AS MC68349 has no built-in Timer, the following code doesn't work + * in a MC68349. You can't use FIFO full mode for the moment, but + * it should be easy to fix this by using an external timer + * + * Use TIMER 1 for TIMEOUT when using FIFO FULL mode in UART driver + * Use TIMER 2 for timing test suites + * + * Geoffroy Montel + * France Telecom - CNET/DSM/TAM/CAT + * 4, rue du Clos Courtel + * 35512 CESSON-SEVIGNE + * FRANCE + * + * e-mail: g_montel@yahoo.com + * + * $Id$ + */ + +/* + * + * Input parameters: NONE + * + * Output parameters: NONE + * + * NOTE: It is important that the timer start/stop overhead be + * determined when porting or modifying this code. + * + * COPYRIGHT (c) 1989-1998. + * On-Line Applications Research Corporation (OAR). + * Copyright assigned to U.S. Government, 1994. + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.OARcorp.com/rtems/license.html. + */ + +#include <rtems.h> +#include <bsp.h> +#include <m340uart.h> +#include <m340timer.h> +#include <m68340.h> + +#define TIMER1_VECTOR 122 +#define TIMER1_IRQ_LEVEL 5 +#define TIMER1_INTERRUPT_ARBITRATION 5 + +#define TIMER2_VECTOR 123 +#define TIMER2_IRQ_LEVEL 4 +#define TIMER2_INTERRUPT_ARBITRATION 4 + +#define CLOCK_SPEED 25 /* in Mhz */ + +#define max(a,b) (((a)>(b)) ? (a) : (b)) + +void (*Restart_Fifo_Full_A_Timer)(); +void (*Restart_Check_A_Timer)(); +void (*Restart_Fifo_Full_B_Timer)(); +void (*Restart_Check_B_Timer)(); + +int preload = 0; + +/****************************************************** + Name: __Restart_Fifo_Full_Timer + Input parameters: - + Output parameters: - + Description: when a character is received, sets + the TIMER to raise an interrupt at + TIMEOUT. + It's necessary to prevent from not + getting n-1 characters (with n the + Uart Fifo size) + *****************************************************/ +void __Restart_Fifo_Full_Timer (void) +{ + TSR1 |= m340_TO; + TCR1 &= ~m340_CPE; + WPREL11 = preload; + TCR1 |= m340_CPE; +} + +/****************************************************** + Name: __Restart_Fifo_Full_Timer + Input parameters: - + Output parameters: - + Description: when no character has been received + recently, check now and then if whether + a there's a character in the FIFO + *****************************************************/ +void __Restart_Check_Timer (void) +{ + TSR1 |= m340_TO; + TCR1 &= ~m340_CPE; + WPREL11 = 0xFFFF; + TCR1 |= m340_CPE; +} + +/****************************************************** + Name: __do_nothing + Input parameters: - + Output parameters: - + Description: we always restart the fifo full timer + with a call to Restart_*_Timer + if we do not use FIFO full, Restart_*_Timer + are set to do __do_nothing + *****************************************************/ +void __do_nothing (void) +{ +} + +#define Fifo_Full_on_A (m340_uart_config[UART_CHANNEL_A].rx_mode==UART_FIFO_FULL && m340_uart_config[UART_CHANNEL_A].enable && m340_uart_config[UART_CHANNEL_A].mode==UART_INTERRUPTS) +#define Fifo_Full_on_B (m340_uart_config[UART_CHANNEL_B].rx_mode==UART_FIFO_FULL && m340_uart_config[UART_CHANNEL_B].enable && m340_uart_config[UART_CHANNEL_B].mode==UART_INTERRUPTS) + +/****************************************************** + Name: Fifo_Full_Timer_initialize + Input parameters: - + Output parameters: - + Description: initialize Timer 1 for FIFO full mode + *****************************************************/ +void Fifo_Full_Timer_initialize (void) +{ + float max_baud_rate; + int prescaler_output_tap = -1; + int nb_of_clock_ticks = 0; + + /* + * USE TIMER 1 for UART FIFO FULL mode + */ + + if ( Fifo_Full_on_A || Fifo_Full_on_B ) + { + /* Disable the timer */ + TCR1 &= ~m340_SWR; + + /* Reset the interrupts */ + TSR1 &= ~(m340_TO | m340_TG | m340_TC); + + /* Init the stop bit for normal operation, ignore FREEZE, user privileges, + set interrupt arbitration */ + TMCR1 = TIMER1_INTERRUPT_ARBITRATION; + + /* interrupt priority level and interrupt vector */ + TIR1 = TIMER1_VECTOR | (TIMER1_IRQ_LEVEL << 8); + + /* compute prescaler */ + if ( Fifo_Full_on_A && Fifo_Full_on_B) + max_baud_rate = max(m340_uart_config[UART_CHANNEL_A].rx_baudrate, m340_uart_config[UART_CHANNEL_B].rx_baudrate); + else if ( Fifo_Full_on_A ) + max_baud_rate = m340_uart_config[UART_CHANNEL_A].rx_baudrate; + else max_baud_rate = m340_uart_config[UART_CHANNEL_B].rx_baudrate; + + /* find out config */ + nb_of_clock_ticks = (10/max_baud_rate)*(CLOCK_SPEED*1000000)*1.2; + if (nb_of_clock_ticks < 0xFFFF) { + preload = nb_of_clock_ticks; + prescaler_output_tap = -1; + } else if (nb_of_clock_ticks/2 < 0xFFFF) { + preload = nb_of_clock_ticks/2; + prescaler_output_tap = m340_Divide_by_2; + } else if (nb_of_clock_ticks/4 < 0xFFFF) { + preload = nb_of_clock_ticks/4; + prescaler_output_tap = m340_Divide_by_4; + } else if (nb_of_clock_ticks/8 < 0xFFFF) { + preload = nb_of_clock_ticks/8; + prescaler_output_tap = m340_Divide_by_16; + } else if (nb_of_clock_ticks/16 < 0xFFFF) { + preload = nb_of_clock_ticks/16; + prescaler_output_tap = m340_Divide_by_16; + } else if (nb_of_clock_ticks/32 < 0xFFFF) { + preload = nb_of_clock_ticks/32; + prescaler_output_tap = m340_Divide_by_32; + } else if (nb_of_clock_ticks/64 < 0xFFFF) { + preload = nb_of_clock_ticks/64; + prescaler_output_tap = m340_Divide_by_64; + } else if (nb_of_clock_ticks/128 < 0xFFFF) { + preload = nb_of_clock_ticks/128; + prescaler_output_tap = m340_Divide_by_128; + } else if (nb_of_clock_ticks/256 < 0xFFFF) { + preload = nb_of_clock_ticks/256; + prescaler_output_tap = m340_Divide_by_256; + } + + /* Input Capture/Output Compare (ICOC) */ + TCR1 = m340_SWR | m340_TO_Enabled | m340_ICOC; + if (prescaler_output_tap!=-1) TCR1 |= prescaler_output_tap | m340_PSE; + + /* install interrupt vector */ + { + rtems_isr_entry old_handler; + rtems_status_code sc; + + proc_ptr ignored; + extern void _Debug_ISR_Handler_Console(void); + + sc = rtems_interrupt_catch (InterruptHandler, + TIMER1_VECTOR, + &old_handler); + + /* uncomment this if you want to pass control to your own ISR handler + it may be usefull to do so to check for performances with an oscilloscope */ + /* + _CPU_ISR_install_raw_handler( TIMER1_VECTOR, _Debug_ISR_Handler_Console, &ignored ); + */ + } + } /* fifo full mode on a uart */ + + /* install routines */ + Restart_Check_A_Timer = Fifo_Full_on_A ? __Restart_Check_Timer : __do_nothing; + Restart_Fifo_Full_A_Timer = Fifo_Full_on_A ? __Restart_Fifo_Full_Timer : __do_nothing; + Restart_Check_B_Timer = Fifo_Full_on_B ? __Restart_Check_Timer : __do_nothing; + Restart_Fifo_Full_B_Timer = Fifo_Full_on_B ? __Restart_Fifo_Full_Timer : __do_nothing; + /* start checking timer */ + Restart_Check_A_Timer(); + Restart_Check_B_Timer(); +} + +/****************************************************** + Name: Timer_initialize + Input parameters: - + Output parameters: - + Description: init Timer for timing test suites + *****************************************************/ +void Timer_initialize (void) +{ + /* Disable the timer */ + TCR2 &= ~m340_SWR; + + /* Reset the interrupts */ + TSR2 &= ~(m340_TO | m340_TG | m340_TC); + + /* Init the stop bit for normal operation, ignore FREEZE, user privileges, + set interrupt arbitration */ + TMCR1 = TIMER2_INTERRUPT_ARBITRATION; + + /* interrupt priority level and interrupt vector */ + TIR1 = TIMER2_VECTOR | (TIMER2_IRQ_LEVEL << 8); + + /* Init the stop bit for normal operation, ignore FREEZE, user privileges, + set interrupt arbitration */ + TMCR2 = TIMER2_INTERRUPT_ARBITRATION; + + /* Preload register 1 */ + WPREL21 = 0xFFFF; + + /* Input Capture/Output Compare (ICOC) */ + TCR2 = m340_SWR | m340_ICOC | m340_PSE | m340_Divide_by_16 | m340_CPE; +} + +/****************************************************** + Name: Read_timer + Input parameters: - + Output parameters: - + Description: Return timer value in microsecond units + *****************************************************/ +int +Read_timer (void) +{ + /* there's CLOCK_SPEED / 16 micro seconds between two timer register decrement */ + return (((0xFFFF - TCNTR2) * CLOCK_SPEED) / 16); +} + +/****************************************************** + Name: Empty_function + Input parameters: - + Output parameters: - + Description: Empty function call used in loops to + measure basic cost of looping + in Timing Test Suite. + *****************************************************/ +rtems_status_code +Empty_function (void) +{ + return RTEMS_SUCCESSFUL; +} + +/****************************************************** + Name: Set_find_average_overhead + Input parameters: - + Output parameters: - + Description: - + *****************************************************/ +void +Set_find_average_overhead(rtems_boolean find_flag) +{ +} |