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cc2538: sys_ctrl: Make it possible to use the 32-kHz crystal

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Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
This commit is contained in:
Benoît Thébaudeau 2013-11-04 21:34:53 +01:00
parent a6227e1e3e
commit 47d570343e
3 changed files with 46 additions and 5 deletions
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32
cpu/cc2538/dev/sys-ctrl.c
View file

@ -35,20 +35,39 @@
* \file
* Implementation of the cc2538 System Control driver
*/
#include "contiki.h"
#include "reg.h"
#include "cpu.h"
#include "dev/sys-ctrl.h"
#include "dev/gpio.h"
#include "dev/ioc.h"
#include <stdint.h>
#if SYS_CTRL_OSC32K_USE_XTAL
#define SYS_CTRL_OSCS 0
#else
#define SYS_CTRL_OSCS SYS_CTRL_CLOCK_CTRL_OSC32K
#endif
/*---------------------------------------------------------------------------*/
void
sys_ctrl_init()
{
uint32_t val;
#if SYS_CTRL_OSC32K_USE_XTAL
/* Set the XOSC32K_Q pads to analog for crystal */
GPIO_SOFTWARE_CONTROL(GPIO_PORT_TO_BASE(GPIO_D_NUM), GPIO_PIN_MASK(6));
GPIO_SET_INPUT(GPIO_PORT_TO_BASE(GPIO_D_NUM), GPIO_PIN_MASK(6));
ioc_set_over(GPIO_D_NUM, 6, IOC_OVERRIDE_ANA);
GPIO_SOFTWARE_CONTROL(GPIO_PORT_TO_BASE(GPIO_D_NUM), GPIO_PIN_MASK(7));
GPIO_SET_INPUT(GPIO_PORT_TO_BASE(GPIO_D_NUM), GPIO_PIN_MASK(7));
ioc_set_over(GPIO_D_NUM, 7, IOC_OVERRIDE_ANA);
#endif
/*
* Desired Clock Ctrl configuration:
* 32KHz source: RC
* 32KHz source: RC or crystal, according to SYS_CTRL_OSC32K_USE_XTAL
* System Clock: 32 MHz
* Power Down Unused
* I/O Div: 16MHz
@ -56,11 +75,18 @@ sys_ctrl_init()
* Rest: Don't care
*/
val = SYS_CTRL_CLOCK_CTRL_OSC32K | SYS_CTRL_CLOCK_CTRL_OSC_PD
val = SYS_CTRL_OSCS | SYS_CTRL_CLOCK_CTRL_OSC_PD
| SYS_CTRL_CLOCK_CTRL_IO_DIV_16MHZ | SYS_CTRL_CLOCK_CTRL_SYS_DIV_16MHZ;
REG(SYS_CTRL_CLOCK_CTRL) = val;
while((REG(SYS_CTRL_CLOCK_STA) & SYS_CTRL_CLOCK_STA_OSC) != 0);
while((REG(SYS_CTRL_CLOCK_STA) & (SYS_CTRL_CLOCK_STA_OSC32K |
SYS_CTRL_CLOCK_STA_OSC)) != SYS_CTRL_OSCS);
#if SYS_CTRL_OSC32K_USE_XTAL
/* Wait for the 32-kHz crystal oscillator to stabilize */
while(REG(SYS_CTRL_CLOCK_STA) & SYS_CTRL_CLOCK_STA_SYNC_32K);
while(!(REG(SYS_CTRL_CLOCK_STA) & SYS_CTRL_CLOCK_STA_SYNC_32K));
#endif
}
/*---------------------------------------------------------------------------*/
void

17
cpu/cc2538/dev/sys-ctrl.h
View file

@ -228,11 +228,26 @@
#define SYS_CTRL_PMCTL_PM0 0x00000000 /**< PM0 */
/** @} */
/*---------------------------------------------------------------------------*/
/** \name SysCtrl 32-kHz oscillator selection
*
* Prefer the crystal oscillator for time accuracy, and the RC oscillator for
* cost and power consumption
* @{
*/
/* Defaults to RC oscillator unless the configuration tells us otherwise */
#ifdef SYS_CTRL_CONF_OSC32K_USE_XTAL
#define SYS_CTRL_OSC32K_USE_XTAL SYS_CTRL_CONF_OSC32K_USE_XTAL
#else
#define SYS_CTRL_OSC32K_USE_XTAL 0
#endif
/** @} */
/*---------------------------------------------------------------------------*/
/** \name SysCtrl functions
* @{
*/
/** \brief Initialises the System Control Driver. The main purpose of this
* function is to power up and select clocks and oscillators */
* function is to power up and select clocks and oscillators
* \note This function depends on ioc_init() having been called beforehand. */
void sys_ctrl_init();
/** \brief Generates a warm reset through the SYS_CTRL_PWRDBG register */

2
platform/cc2538dk/contiki-main.c
View file

@ -127,12 +127,12 @@ int
main(void)
{
nvic_init();
ioc_init();
sys_ctrl_init();
clock_init();
lpm_init();
rtimer_init();
gpio_init();
ioc_init();
leds_init();
fade(LEDS_YELLOW);