linux/arch/arm/mach-omap2/cm4xxx.c
Benoit Cousson 9a23dfe128 OMAP4: hwmod & CM: Implement the omap4_cm_wait_module_ready function
The return of the omap4_cm_wait_module_ready function is checked
in order to avoid accessing the sysconfig register if the module is
not in the correct state.
In that case the _setup will exit without trying to reset
using sysconfig.
For the moment a warning is printed. A proper management of fclk
and module reset will have to be done in order to init correctly
the problematic IPs listed below.

  <4>omap_hwmod: ivahd: cannot be enabled (3)
  <4>omap_hwmod: iss: cannot be enabled (3)
  <4>omap_hwmod: tesla: cannot be enabled (3)
  <4>omap_hwmod: sdma: cannot be enabled (3)
  <4>omap_hwmod: sl2: cannot be enabled (3)
  <4>omap_hwmod: sad2d: cannot be enabled (3)
  <4>omap_hwmod: ducati: cannot be enabled (3)

Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-05-20 12:31:08 -06:00

62 lines
1.7 KiB
C

/*
* 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 <plat/common.h>
#include "cm.h"
#include "cm-regbits-44xx.h"
/**
* omap4_cm_wait_module_ready - wait for a module to be in 'func' state
* @clkctrl_reg: CLKCTRL module address
*
* Wait for the module IDLEST to be functional. If the idle state is in any
* the non functional state (trans, idle or disabled), module and thus the
* sysconfig cannot be accessed and will probably lead to an "imprecise
* external abort"
*
* Module idle state:
* 0x0 func: Module is fully functional, including OCP
* 0x1 trans: Module is performing transition: wakeup, or sleep, or sleep
* abortion
* 0x2 idle: Module is in Idle mode (only OCP part). It is functional if
* using separate functional clock
* 0x3 disabled: Module is disabled and cannot be accessed
*
* TODO: Need to handle module accessible in idle state
*/
int omap4_cm_wait_module_ready(void __iomem *clkctrl_reg)
{
int i = 0;
if (!clkctrl_reg)
return 0;
omap_test_timeout(((__raw_readl(clkctrl_reg) &
OMAP4430_IDLEST_MASK) == 0),
MAX_MODULE_READY_TIME, i);
return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
}