diff options
Diffstat (limited to 'arch/arm/mach-omap2/cm4xxx.c')
-rw-r--r-- | arch/arm/mach-omap2/cm4xxx.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/cm4xxx.c b/arch/arm/mach-omap2/cm4xxx.c new file mode 100644 index 000000000000..e4ebd6d53135 --- /dev/null +++ b/arch/arm/mach-omap2/cm4xxx.c @@ -0,0 +1,68 @@ +/* + * OMAP4 CM module functions + * + * Copyright (C) 2009 Nokia Corporation + * Paul Walmsley + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/delay.h> +#include <linux/spinlock.h> +#include <linux/list.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/io.h> + +#include <asm/atomic.h> + +#include "cm.h" +#include "cm-regbits-4xxx.h" + +/* XXX move this to cm.h */ +/* MAX_MODULE_READY_TIME: max milliseconds for module to leave idle */ +#define MAX_MODULE_READY_TIME 20000 + +/* + * OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK: isolates the IDLEST field in the + * CM_CLKCTRL register. + */ +#define OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK (0x2 << 16) + +/* + * OMAP4 prcm_mod u32 fields contain packed data: the CM ID in bit 16 and + * the PRCM module offset address (from the CM module base) in bits 15-0. + */ +#define OMAP4_PRCM_MOD_CM_ID_SHIFT 16 +#define OMAP4_PRCM_MOD_OFFS_MASK 0xffff + +/** + * omap4_cm_wait_idlest_ready - wait for a module to leave idle or standby + * @prcm_mod: PRCM module offset (XXX example) + * @prcm_dev_offs: PRCM device offset (e.g. MCASP XXX example) + * + * XXX document + */ +int omap4_cm_wait_idlest_ready(u32 prcm_mod, u8 prcm_dev_offs) +{ + int i = 0; + u8 cm_id; + u16 prcm_mod_offs; + u32 mask = OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK; + + cm_id = prcm_mod >> OMAP4_PRCM_MOD_CM_ID_SHIFT; + prcm_mod_offs = prcm_mod & OMAP4_PRCM_MOD_OFFS_MASK; + + while (((omap4_cm_read_mod_reg(cm_id, prcm_mod_offs, prcm_dev_offs, + OMAP4_CM_CLKCTRL_DREG) & mask) != 0) && + (i++ < MAX_MODULE_READY_TIME)) + udelay(1); + + return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY; +} + |