nuttx/arch/arm/src/sam34/sam_clockconfig.c
2014-03-18 09:31:02 -06:00

375 lines
12 KiB
C

/****************************************************************************
* arch/arm/src/chip/sam_clockconfig.c
*
* Copyright (C) 2010, 2013-2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <arch/board/board.h>
#include "up_arch.h"
#include "up_internal.h"
#include "sam_clockconfig.h"
#include "chip/sam_pmc.h"
#include "chip/sam_eefc.h"
#include "chip/sam_wdt.h"
#include "chip/sam_supc.h"
#include "chip/sam_matrix.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* PMC register settings based on the board configuration values defined
* in board.h
*/
#define BOARD_CKGR_MOR (PMC_CKGR_MOR_KEY | BOARD_CKGR_MOR_MOSCXTST | \
PMC_CKGR_MOR_MOSCRCEN | PMC_CKGR_MOR_MOSCXTEN)
#if defined(CONFIG_ARCH_CHIP_SAM3U)
# define BOARD_CKGR_PLLAR (PMC_CKGR_PLLAR_ONE | BOARD_CKGR_PLLAR_MUL | \
BOARD_CKGR_PLLAR_STMODE | BOARD_CKGR_PLLAR_COUNT | \
BOARD_CKGR_PLLAR_DIV)
#elif defined(CONFIG_ARCH_CHIP_SAM3A) || defined(CONFIG_ARCH_CHIP_SAM3X)
# define BOARD_CKGR_PLLAR (PMC_CKGR_PLLAR_ONE | BOARD_CKGR_PLLAR_MUL | \
BOARD_CKGR_PLLAR_COUNT | BOARD_CKGR_PLLAR_DIV)
#elif defined(CONFIG_ARCH_CHIP_SAM4S) || defined(CONFIG_ARCH_CHIP_SAM4E)
# define BOARD_CKGR_PLLAR (PMC_CKGR_PLLAR_ONE | BOARD_CKGR_PLLAR_MUL | \
BOARD_CKGR_PLLAR_COUNT | BOARD_CKGR_PLLAR_DIV)
#endif
#define BOARD_PMC_MCKR_FAST (BOARD_PMC_MCKR_PRES | PMC_MCKR_CSS_MAIN)
#define BOARD_PMC_MCKR (BOARD_PMC_MCKR_PRES | BOARD_PMC_MCKR_CSS)
#define BOARD_CKGR_UCKR (BOARD_CKGR_UCKR_UPLLCOUNT | PMC_CKGR_UCKR_UPLLEN)
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: sam_efcsetup
*
* Description:
* Configure 2 waitstates for embedded flash access
*
****************************************************************************/
static inline void sam_efcsetup(void)
{
putreg32((BOARD_FWS << EEFC_FMR_FWS_SHIFT), SAM_EEFC0_FMR);
#if !defined(CONFIG_ARCH_CHIP_SAM4E)
putreg32((BOARD_FWS << EEFC_FMR_FWS_SHIFT), SAM_EEFC1_FMR);
#endif
}
/****************************************************************************
* Name: sam_wdtsetup
*
* Description:
* Disable the watchdog timer
*
****************************************************************************/
static inline void sam_wdtsetup(void)
{
putreg32(WDT_MR_WDDIS, SAM_WDT_MR);
}
/****************************************************************************
* Name: sam_supcsetup
*
* Description:
* Select the external slow clock
*
****************************************************************************/
static inline void sam_supcsetup(void)
{
/* Check if the 32-kHz is already selected */
if ((getreg32(SAM_SUPC_SR) & SUPC_SR_OSCSEL) == 0)
{
uint32_t delay;
putreg32((SUPC_CR_XTALSEL|SUPR_CR_KEY), SAM_SUPC_CR);
for (delay = 0;
(getreg32(SAM_SUPC_SR) & SUPC_SR_OSCSEL) == 0 && delay < UINT32_MAX;
delay++);
}
}
/****************************************************************************
* Name: sam_pmcwait
*
* Description:
* Wait for the specified PMC status bit to become "1"
*
****************************************************************************/
static void sam_pmcwait(uint32_t bit)
{
volatile uint32_t delay;
for (delay = 0;
(getreg32(SAM_PMC_SR) & bit) == 0 && delay < UINT32_MAX;
delay++);
}
/****************************************************************************
* Name: sam_pmcsetup
*
* Description:
* Initialize clocking
*
****************************************************************************/
static inline void sam_pmcsetup(void)
{
uint32_t regval;
/* Enable main oscillator (if it has not already been selected) */
if ((getreg32(SAM_PMC_CKGR_MOR) & PMC_CKGR_MOR_MOSCSEL) == 0)
{
/* "When the MOSCXTEN bit and the MOSCXTCNT are written in CKGR_MOR to
* enable the main oscillator, the MOSCXTS bit in the Power Management
* Controller Status Register (PMC_SR) is cleared and the counter starts
* counting down on the slow clock divided by 8 from the MOSCXTCNT
* value. ... When the counter reaches 0, the MOSCXTS bit is set,
* indicating that the main clock is valid."
*/
putreg32(BOARD_CKGR_MOR, SAM_PMC_CKGR_MOR);
sam_pmcwait(PMC_INT_MOSCXTS);
}
/* "Switch to the main oscillator. The selection is made by writing the
* MOSCSEL bit in the Main Oscillator Register (CKGR_MOR). The switch of
* the Main Clock source is glitch free, so there is no need to run out
* of SLCK, PLLACK or UPLLCK in order to change the selection. The MOSCSELS
* bit of the power Management Controller Status Register (PMC_SR) allows
* knowing when the switch sequence is done."
*
* MOSCSELS: Main Oscillator Selection Status
* 0 = Selection is done
* 1 = Selection is in progress
*/
putreg32((BOARD_CKGR_MOR | PMC_CKGR_MOR_MOSCSEL), SAM_PMC_CKGR_MOR);
sam_pmcwait(PMC_INT_MOSCSELS);
/* "Select the master clock. "The Master Clock selection is made by writing
* the CSS field (Clock Source Selection) in PMC_MCKR (Master Clock Register).
* The prescaler supports the division by a power of 2 of the selected clock
* between 1 and 64, and the division by 3. The PRES field in PMC_MCKR programs
* the prescaler. Each time PMC_MCKR is written to define a new Master Clock,
* the MCKRDY bit is cleared in PMC_SR. It reads 0 until the Master Clock is
* established.
*/
regval = getreg32(SAM_PMC_MCKR);
regval &= ~PMC_MCKR_CSS_MASK;
regval |= PMC_MCKR_CSS_MAIN;
putreg32(regval, SAM_PMC_MCKR);
sam_pmcwait(PMC_INT_MCKRDY);
#if defined(CONFIG_ARCH_CHIP_SAM4E)
/* Setup the maximum value for the PLLAR multiplier. The PMMR register
* "defines the maximum value of multiplication factor that can be sent to
* PLLA. Any value of the MULA bitfield ... above PLLA_MMAX is saturated
* to PLLA_MMAX.
*/
//putreg32(PMC_PMMR_MASK, SAM_PMC_PMMR);
#endif
/* Setup PLLA and wait for LOCKA */
putreg32(BOARD_CKGR_PLLAR, SAM_PMC_CKGR_PLLAR);
sam_pmcwait(PMC_INT_LOCKA);
#ifdef CONFIG_USBDEV
/* Setup UTMI for USB and wait for LOCKU */
#ifdef SAM_PMC_CKGR_UCKR
/* This MCU has a USB PLL. Configure the UPLL and wait for it to lock. */
regval = getreg32(SAM_PMC_CKGR_UCKR);
regval |= BOARD_CKGR_UCKR;
putreg32(regval, SAM_PMC_CKGR_UCKR);
sam_pmcwait(PMC_INT_LOCKU);
#else
/* This board does not have a UPLL. Use the output of PLLA or PLLA
* (depending on USBS) and setup the PLL divisor to generate the 48MHz
* USB clock.
*/
regval = (BOARD_PMC_USBS | BOARD_PMC_USBDIV);
putreg32(regval, SAM_PMC_USB);
#if 0 /* Done in the UDP driver */
/* Set the UDP bit in the SCER register to enable the USB clock output */
regval = getreg32(SAM_PMC_SCER);
regval |= PMC_UDP;
putreg32(regval, SAM_PMC_SCER);
#endif /* 0 */
#endif /* SAM_PMC_CKGR_UCKR */
#endif /* CONFIG_USBDEV */
/* Switch to the fast clock and wait for MCKRDY */
putreg32(BOARD_PMC_MCKR_FAST, SAM_PMC_MCKR);
sam_pmcwait(PMC_INT_MCKRDY);
putreg32(BOARD_PMC_MCKR, SAM_PMC_MCKR);
sam_pmcwait(PMC_INT_MCKRDY);
}
/****************************************************************************
* Name: sam_enabledefaultmaster and sam_disabledefaultmaster
*
* Description:
* Enable/disable default master access
*
****************************************************************************/
static inline void sam_enabledefaultmaster(void)
{
uint32_t regval;
/* Set default master: SRAM0 -> Cortex-M3 System */
regval = getreg32(SAM_MATRIX_SCFG0);
regval |= (MATRIX_SCFG0_FIXEDDEFMSTR_ARMS|MATRIX_SCFG_DEFMSTRTYPE_FIXED);
putreg32(regval, SAM_MATRIX_SCFG0);
/* Set default master: SRAM1 -> Cortex-M3 System */
regval = getreg32(SAM_MATRIX_SCFG1);
regval |= (MATRIX_SCFG1_FIXEDDEFMSTR_ARMS|MATRIX_SCFG_DEFMSTRTYPE_FIXED);
putreg32(regval, SAM_MATRIX_SCFG1);
/* Set default master: Internal flash0 -> Cortex-M3 Instruction/Data */
regval = getreg32(SAM_MATRIX_SCFG3);
regval |= (MATRIX_SCFG3_FIXEDDEFMSTR_ARMC|MATRIX_SCFG_DEFMSTRTYPE_FIXED);
putreg32(regval, SAM_MATRIX_SCFG3);
}
#if 0 /* Not used */
static inline void sam_disabledefaultmaster(void)
{
uint32_t regval;
/* Clear default master: SRAM0 -> Cortex-M3 System */
regval = getreg32(SAM_MATRIX_SCFG0);
regval &= ~MATRIX_SCFG_DEFMSTRTYPE_MASK;
putreg32(regval, SAM_MATRIX_SCFG0);
/* Clear default master: SRAM1 -> Cortex-M3 System */
regval = getreg32(SAM_MATRIX_SCFG1);
regval &= ~MATRIX_SCFG_DEFMSTRTYPE_MASK;
putreg32(regval, SAM_MATRIX_SCFG1);
/* Clear default master: Internal flash0 -> Cortex-M3 Instruction/Data */
regval = getreg32(SAM_MATRIX_SCFG3);
regval &= ~MATRIX_SCFG_DEFMSTRTYPE_MASK;
putreg32(regval, SAM_MATRIX_SCFG3);
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/************************************************************************************
* Name: sam_clockconfig
*
* Description:
* Called to initialize the SAM3/4. This does whatever setup is needed to put the
* SoC in a usable state. This includes the initialization of clocking using the
* settings in board.h. (After power-on reset, the SAM3/4 is initially running on
* a 4MHz internal RC clock). This function also performs other low-level chip
* initialization of the chip including EFC, master clock, IRQ & watchdog
* configuration.
*
************************************************************************************/
void sam_clockconfig(void)
{
/* Configure embedded flash access */
sam_efcsetup();
/* Configure the watchdog timer */
sam_wdtsetup();
/* Setup the supply controller to use the external slow clock */
sam_supcsetup();
/* Initialize clocking */
sam_pmcsetup();
/* Optimize CPU setting for speed */
sam_enabledefaultmaster();
}