diff options
Diffstat (limited to 'bsps/arm/rtl22xx/clock/clockdrv.c')
| -rw-r--r-- | bsps/arm/rtl22xx/clock/clockdrv.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/bsps/arm/rtl22xx/clock/clockdrv.c b/bsps/arm/rtl22xx/clock/clockdrv.c new file mode 100644 index 0000000000..84ab9c063b --- /dev/null +++ b/bsps/arm/rtl22xx/clock/clockdrv.c @@ -0,0 +1,177 @@ +/* + * LPC22XX/LPC21xx clock specific using the System Timer + * + * Set the Time0 to generate click for RTEMS + */ + +/* + * Copyright (c) 2006 by Ray <rayx.cn@gmail.com> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#include <rtems.h> +#include <bsp.h> +#include <bsp/irq.h> +#include <lpc22xx.h> +#include <rtems/bspIo.h> /* for printk */ +#include <rtems/timecounter.h> + +void Clock_isr(rtems_irq_hdl_param arg); +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); + +static rtems_timecounter_simple lpc22xx_tc; + +static uint32_t lpc22xx_tc_get(rtems_timecounter_simple *tc) +{ + return T0TC; +} + +static bool lpc22xx_tc_is_pending(rtems_timecounter_simple *tc) +{ + return (T0IR & 0x1) != 0; +} + +static uint32_t lpc22xx_tc_get_timecount(struct timecounter *tc) +{ + return rtems_timecounter_simple_upcounter_get( + tc, + lpc22xx_tc_get, + lpc22xx_tc_is_pending + ); +} + +/** + * When we get the clock interrupt + * - clear the interrupt bit? + * - restart the timer? + */ +static void lpc22xx_tc_at_tick(rtems_timecounter_simple *tc) +{ + if (!(T0IR & 0x01)) + return; + T0IR = 0x01; + VICVectAddr = 0x00; +} + +static void lpc22xx_tc_tick(void) +{ + rtems_timecounter_simple_upcounter_tick( + &lpc22xx_tc, + lpc22xx_tc_get, + lpc22xx_tc_at_tick + ); +} + +/* Replace the first value with the clock's interrupt name. */ +rtems_irq_connect_data clock_isr_data = { + .name = LPC22xx_INTERRUPT_TIMER0, + .hdl = Clock_isr, + .handle = NULL, + .on = clock_isr_on, + .off = clock_isr_off, + .isOn = clock_isr_is_on, +}; + +/* use the /shared/dev/clock/clockimpl.h code template */ + +/** + * Installs the clock ISR. You shouldn't need to change this. + */ +#define Clock_driver_support_install_isr( _new ) \ + BSP_install_rtems_irq_handler(&clock_isr_data) + +/** + * 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 + * rtems_configuration_get_microseconds_per_tick() + * MR0/(LPC22xx_Fpclk/(PR0+1)) = 10/1000 = 0.01s + */ +#define Clock_driver_support_initialize_hardware() \ + do { \ + /* disable and clear timer 0, set to */ \ + T0TCR &= 0; \ + /* TC is incremented on every pclk.*/ \ + T0PC = 0; \ + /* initialize the timer period and prescaler */ \ + T0MR0 = ((LPC22xx_Fpclk/1000 * \ + rtems_configuration_get_microseconds_per_tick()) / 1000); \ + /* generate interrupt when T0MR0 match T0TC and Reset Timer Count*/ \ + T0MCR |= 0x03; \ + /* No external match */ \ + T0EMR = 0; \ + /* enable timer0 */ \ + T0TCR = 1; \ + /* enable interrupt, skyeye will check this*/ \ + T0IR |= 0x01; \ + /* install timecounter */ \ + rtems_timecounter_simple_install( \ + &lpc22xx_tc, \ + LPC22xx_Fpclk, \ + T0MR0, \ + lpc22xx_tc_get_timecount \ + ); \ + } 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; +} + +/** + * 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; +} + +/** + * 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 */ +} + +#define Clock_driver_timecounter_tick() lpc22xx_tc_tick() + +/* Make sure to include this, and only at the end of the file */ +#include "../../../shared/dev/clock/clockimpl.h" + |