/* * LPC22XX clock specific using the System Timer * set the Time0 * This is hardware specific part of the clock driver. At the end of this * file, the generic part of the driver is #included. * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at * * http://www.rtems.com/license/LICENSE. * * * $Id$ */ #include #include #include #include #include /* for printk */ /* this is defined in ../../../shared/clockdrv_shell.c */ rtems_isr Clock_isr(rtems_vector_number vector); static void clock_isr_on(const rtems_irq_connect_data *unused); static void clock_isr_off(const rtems_irq_connect_data *unused); static int clock_isr_is_on(const rtems_irq_connect_data *irq); /* Replace the first value with the clock's interrupt name. */ rtems_irq_connect_data clock_isr_data = {LPC22xx_INTERRUPT_TIMER0, (rtems_irq_hdl)Clock_isr, clock_isr_on, clock_isr_off, clock_isr_is_on, 3, /* unused for ARM cpus */ 0 }; /* unused for ARM cpus */ /* If you follow the code, this is never used, so any value * should work */ #define CLOCK_VECTOR 0 /*use the /shared/clockdrv_shell.c code template */ /** * When we get the clock interrupt * - clear the interrupt bit? * - restart the timer? */ #define Clock_driver_support_at_tick() \ do { \ if (!(T0IR & 0x01)) return; \ T0IR = 0x01; \ VICVectAddr = 0x00;\ } while(0) /** * Installs the clock ISR. You shouldn't need to change this. */ #define Clock_driver_support_install_isr( _new, _old ) \ do { \ (_old) = NULL; \ BSP_install_rtems_irq_handler(&clock_isr_data); \ } while(0) /** * Initialize the hardware for the clock * - Set the frequency * - enable it * - clear any pending interrupts * * Since you may want the clock always running, you can * enable interrupts here. If you do so, the clock_isr_on(), * clock_isr_off(), and clock_isr_is_on() functions can be * NOPs. */ /* set timer to generate interrupt every BSP_Configuration.microseconds_per_tick */ /* MR0/(LPC22xx_Fpclk/(PR0+1)) = 10/1000 = 0.01s */ #define Clock_driver_support_initialize_hardware() \ do { \ T0TCR &= 0; /* disable and clear timer 0, set to */ \ T0PC = 0; /* TC is incrementet on every pclk.*/ \ T0MR0 = ((LPC22xx_Fpclk/1000* BSP_Configuration.microseconds_per_tick) / 1000); /* initialize the timer period and prescaler */ \ /*T0PR = (((LPC22xx_Fpclk / 1000) * BSP_Configuration.microseconds_per_tick) / 1000-1); \ */ \ T0MCR |= 0x03; /* generate interrupt when T0MR0 match T0TC and Reset Timer Count*/ \ T0EMR = 0; /*No external match*/ \ T0TCR = 1; /*enable timer0*/ \ } while (0) /** * Do whatever you need to shut the clock down and remove the * interrupt handler. Since this normally only gets called on * RTEMS shutdown, you may not need to do anything other than * remove the ISR. */ #define Clock_driver_support_shutdown_hardware() \ do { \ /* Disable timer */ \ T0TCR&=~0x02; \ BSP_remove_rtems_irq_handler(&clock_isr_data); \ } while (0) /** * Enables clock interrupt. * * If the interrupt is always on, this can be a NOP. */ static void clock_isr_on(const rtems_irq_connect_data *unused) { T0IR&=0x01; //return; } /** * Disables clock interrupts * * If the interrupt is always on, this can be a NOP. */ static void clock_isr_off(const rtems_irq_connect_data *unused) { T0IR=0x00; //return; } /** * Tests to see if clock interrupt is enabled, and returns 1 if so. * If interrupt is not enabled, returns 0. * * If the interrupt is always on, this always returns 1. */ static int clock_isr_is_on(const rtems_irq_connect_data *irq) { return T0IR & 0x01; /*MR0 mask*/ } /* Make sure to include this, and only at the end of the file */ #include "../../../../libbsp/shared/clockdrv_shell.c"