aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-omap2/cm4xxx.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-omap2/cm4xxx.c')
-rw-r--r--arch/arm/mach-omap2/cm4xxx.c68
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 @@
1/*
2 * OMAP4 CM module functions
3 *
4 * Copyright (C) 2009 Nokia Corporation
5 * Paul Walmsley
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/types.h>
15#include <linux/delay.h>
16#include <linux/spinlock.h>
17#include <linux/list.h>
18#include <linux/errno.h>
19#include <linux/err.h>
20#include <linux/io.h>
21
22#include <asm/atomic.h>
23
24#include "cm.h"
25#include "cm-regbits-4xxx.h"
26
27/* XXX move this to cm.h */
28/* MAX_MODULE_READY_TIME: max milliseconds for module to leave idle */
29#define MAX_MODULE_READY_TIME 20000
30
31/*
32 * OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK: isolates the IDLEST field in the
33 * CM_CLKCTRL register.
34 */
35#define OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK (0x2 << 16)
36
37/*
38 * OMAP4 prcm_mod u32 fields contain packed data: the CM ID in bit 16 and
39 * the PRCM module offset address (from the CM module base) in bits 15-0.
40 */
41#define OMAP4_PRCM_MOD_CM_ID_SHIFT 16
42#define OMAP4_PRCM_MOD_OFFS_MASK 0xffff
43
44/**
45 * omap4_cm_wait_idlest_ready - wait for a module to leave idle or standby
46 * @prcm_mod: PRCM module offset (XXX example)
47 * @prcm_dev_offs: PRCM device offset (e.g. MCASP XXX example)
48 *
49 * XXX document
50 */
51int omap4_cm_wait_idlest_ready(u32 prcm_mod, u8 prcm_dev_offs)
52{
53 int i = 0;
54 u8 cm_id;
55 u16 prcm_mod_offs;
56 u32 mask = OMAP4_PRCM_CM_CLKCTRL_IDLEST_MASK;
57
58 cm_id = prcm_mod >> OMAP4_PRCM_MOD_CM_ID_SHIFT;
59 prcm_mod_offs = prcm_mod & OMAP4_PRCM_MOD_OFFS_MASK;
60
61 while (((omap4_cm_read_mod_reg(cm_id, prcm_mod_offs, prcm_dev_offs,
62 OMAP4_CM_CLKCTRL_DREG) & mask) != 0) &&
63 (i++ < MAX_MODULE_READY_TIME))
64 udelay(1);
65
66 return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
67}
68