Support AT91CAP9 revC CPUs

The AT91CAP9 revC CPU has a few differences over the previous,
revB CPU which was distributed in small quantities only (revA was
an internal Atmel product only).

The revC silicon needs a special initialisation sequence to
switch from the internal (imprecise) RC oscillator to the
external 32k clock.

Signed-off-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
This commit is contained in:
Stelian Pop 2008-05-08 14:52:34 +02:00 committed by Jean-Christophe PLAGNIOL-VILLARD
parent 098b7b4b44
commit 19883aede2
3 changed files with 46 additions and 1 deletions

View file

@ -72,6 +72,33 @@ static void at91cap9_serial_hw_init(void)
#endif
}
static void at91cap9_slowclock_hw_init(void)
{
/*
* On AT91CAP9 revC CPUs, the slow clock can be based on an
* internal impreciseRC oscillator or an external 32kHz oscillator.
* Switch to the latter.
*/
#define ARCH_ID_AT91CAP9_REVB 0x399
#define ARCH_ID_AT91CAP9_REVC 0x601
if (at91_sys_read(AT91_PMC_VER) == ARCH_ID_AT91CAP9_REVC) {
unsigned i, tmp = at91_sys_read(AT91_SCKCR);
if ((tmp & AT91CAP9_SCKCR_OSCSEL) == AT91CAP9_SCKCR_OSCSEL_RC) {
extern void timer_init(void);
timer_init();
tmp |= AT91CAP9_SCKCR_OSC32EN;
at91_sys_write(AT91_SCKCR, tmp);
for (i = 0; i < 1200; i++)
udelay(1000);
tmp |= AT91CAP9_SCKCR_OSCSEL_32;
at91_sys_write(AT91_SCKCR, tmp);
udelay(200);
tmp &= ~AT91CAP9_SCKCR_RCEN;
at91_sys_write(AT91_SCKCR, tmp);
}
}
}
static void at91cap9_nor_hw_init(void)
{
unsigned long csa;
@ -305,6 +332,7 @@ int board_init(void)
gd->bd->bi_boot_params = PHYS_SDRAM + 0x100;
at91cap9_serial_hw_init();
at91cap9_slowclock_hw_init();
at91cap9_nor_hw_init();
#ifdef CONFIG_CMD_NAND
at91cap9_nand_hw_init();

View file

@ -96,4 +96,9 @@
#define AT91_PMC_PCK3RDY (1 << 11) /* Programmable Clock 3 */
#define AT91_PMC_IMR (AT91_PMC + 0x6c) /* Interrupt Mask Register */
#define AT91_PMC_PROT (AT91_PMC + 0xe4) /* Protect Register [AT91CAP9 revC only] */
#define AT91_PMC_PROTKEY 0x504d4301 /* Activation Code */
#define AT91_PMC_VER (AT91_PMC + 0xfc) /* PMC Module Version [AT91CAP9 only] */
#endif

View file

@ -101,12 +101,24 @@
#define AT91_RTT (0xfffffd20 - AT91_BASE_SYS)
#define AT91_PIT (0xfffffd30 - AT91_BASE_SYS)
#define AT91_WDT (0xfffffd40 - AT91_BASE_SYS)
#define AT91_GPBR (0xfffffd50 - AT91_BASE_SYS)
#define AT91_SCKCR (0xfffffd50 - AT91_BASE_SYS)
#define AT91_GPBR_REVB (0xfffffd50 - AT91_BASE_SYS)
#define AT91_GPBR_REVC (0xfffffd60 - AT91_BASE_SYS)
#define AT91_USART0 AT91CAP9_BASE_US0
#define AT91_USART1 AT91CAP9_BASE_US1
#define AT91_USART2 AT91CAP9_BASE_US2
/*
* SCKCR flags
*/
#define AT91CAP9_SCKCR_RCEN (1 << 0) /* RC Oscillator Enable */
#define AT91CAP9_SCKCR_OSC32EN (1 << 1) /* 32kHz Oscillator Enable */
#define AT91CAP9_SCKCR_OSC32BYP (1 << 2) /* 32kHz Oscillator Bypass */
#define AT91CAP9_SCKCR_OSCSEL (1 << 3) /* Slow Clock Selector */
#define AT91CAP9_SCKCR_OSCSEL_RC (0 << 3)
#define AT91CAP9_SCKCR_OSCSEL_32 (1 << 3)
/*
* Internal Memory.
*/