From 19883aede2ac0a522493bfb2b35a7dbb200071b1 Mon Sep 17 00:00:00 2001 From: Stelian Pop Date: Thu, 8 May 2008 14:52:34 +0200 Subject: 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 Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD --- board/atmel/at91cap9adk/at91cap9adk.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'board/atmel/at91cap9adk') diff --git a/board/atmel/at91cap9adk/at91cap9adk.c b/board/atmel/at91cap9adk/at91cap9adk.c index e353cea..a3eaf19 100644 --- a/board/atmel/at91cap9adk/at91cap9adk.c +++ b/board/atmel/at91cap9adk/at91cap9adk.c @@ -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(); -- cgit v1.1