kernel-ark/arch/arm/mach-omap2/prcm.c
Paul Walmsley 72350b29a4 OMAP2/3 clock: split, rename omap2_wait_clock_ready()
Some OMAP2/3 hardware modules have CM_IDLEST attributes that are not
handled by the current omap2_wait_clock_ready() code.  In preparation
for patches that fix the unusual devices, rename the function
omap2_wait_clock_ready() to omap2_wait_module_ready() and split it
into three parts:

1. A clkops-specific companion clock return function (by default,
   omap2_clk_dflt_find_companion())

2. A clkops-specific CM_IDLEST register address and bit shift return
   function (by default, omap2_clk_dflt_find_idlest())

3. Code to wait for the CM to indicate that the module is ready
   (omap2_cm_wait_idlest())

Clocks can now specify their own custom find_companion() and find_idlest()
functions; used in subsequent patches.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
2009-07-24 20:10:35 -06:00

171 lines
4.1 KiB
C

/*
* linux/arch/arm/mach-omap2/prcm.c
*
* OMAP 24xx Power Reset and Clock Management (PRCM) functions
*
* Copyright (C) 2005 Nokia Corporation
*
* Written by Tony Lindgren <tony.lindgren@nokia.com>
*
* Some pieces of code Copyright (C) 2005 Texas Instruments, Inc.
*
* 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/module.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <mach/common.h>
#include <mach/prcm.h>
#include "clock.h"
#include "prm.h"
#include "prm-regbits-24xx.h"
static void __iomem *prm_base;
static void __iomem *cm_base;
#define MAX_MODULE_ENABLE_WAIT 100000
u32 omap_prcm_get_reset_sources(void)
{
/* XXX This presumably needs modification for 34XX */
return prm_read_mod_reg(WKUP_MOD, RM_RSTST) & 0x7f;
}
EXPORT_SYMBOL(omap_prcm_get_reset_sources);
/* Resets clock rates and reboots the system. Only called from system.h */
void omap_prcm_arch_reset(char mode)
{
s16 prcm_offs;
omap2_clk_prepare_for_reboot();
if (cpu_is_omap24xx())
prcm_offs = WKUP_MOD;
else if (cpu_is_omap34xx())
prcm_offs = OMAP3430_GR_MOD;
else
WARN_ON(1);
prm_set_mod_reg_bits(OMAP_RST_DPLL3, prcm_offs, RM_RSTCTRL);
}
static inline u32 __omap_prcm_read(void __iomem *base, s16 module, u16 reg)
{
BUG_ON(!base);
return __raw_readl(base + module + reg);
}
static inline void __omap_prcm_write(u32 value, void __iomem *base,
s16 module, u16 reg)
{
BUG_ON(!base);
__raw_writel(value, base + module + reg);
}
/* Read a register in a PRM module */
u32 prm_read_mod_reg(s16 module, u16 idx)
{
return __omap_prcm_read(prm_base, module, idx);
}
EXPORT_SYMBOL(prm_read_mod_reg);
/* Write into a register in a PRM module */
void prm_write_mod_reg(u32 val, s16 module, u16 idx)
{
__omap_prcm_write(val, prm_base, module, idx);
}
EXPORT_SYMBOL(prm_write_mod_reg);
/* Read-modify-write a register in a PRM module. Caller must lock */
u32 prm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx)
{
u32 v;
v = prm_read_mod_reg(module, idx);
v &= ~mask;
v |= bits;
prm_write_mod_reg(v, module, idx);
return v;
}
EXPORT_SYMBOL(prm_rmw_mod_reg_bits);
/* Read a register in a CM module */
u32 cm_read_mod_reg(s16 module, u16 idx)
{
return __omap_prcm_read(cm_base, module, idx);
}
EXPORT_SYMBOL(cm_read_mod_reg);
/* Write into a register in a CM module */
void cm_write_mod_reg(u32 val, s16 module, u16 idx)
{
__omap_prcm_write(val, cm_base, module, idx);
}
EXPORT_SYMBOL(cm_write_mod_reg);
/* Read-modify-write a register in a CM module. Caller must lock */
u32 cm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx)
{
u32 v;
v = cm_read_mod_reg(module, idx);
v &= ~mask;
v |= bits;
cm_write_mod_reg(v, module, idx);
return v;
}
EXPORT_SYMBOL(cm_rmw_mod_reg_bits);
/**
* omap2_cm_wait_idlest - wait for IDLEST bit to indicate module readiness
* @reg: physical address of module IDLEST register
* @mask: value to mask against to determine if the module is active
* @name: name of the clock (for printk)
*
* Returns 1 if the module indicated readiness in time, or 0 if it
* failed to enable in roughly MAX_MODULE_ENABLE_WAIT microseconds.
*/
int omap2_cm_wait_idlest(void __iomem *reg, u32 mask, const char *name)
{
int i = 0;
int ena = 0;
/*
* 24xx uses 0 to indicate not ready, and 1 to indicate ready.
* 34xx reverses this, just to keep us on our toes
*/
if (cpu_is_omap24xx())
ena = mask;
else if (cpu_is_omap34xx())
ena = 0;
else
BUG();
/* Wait for lock */
while (((__raw_readl(reg) & mask) != ena) &&
(i++ < MAX_MODULE_ENABLE_WAIT))
udelay(1);
if (i < MAX_MODULE_ENABLE_WAIT)
pr_debug("cm: Module associated with clock %s ready after %d "
"loops\n", name, i);
else
pr_err("cm: Module associated with clock %s didn't enable in "
"%d tries\n", name, MAX_MODULE_ENABLE_WAIT);
return (i < MAX_MODULE_ENABLE_WAIT) ? 1 : 0;
};
void __init omap2_set_globals_prcm(struct omap_globals *omap2_globals)
{
prm_base = omap2_globals->prm;
cm_base = omap2_globals->cm;
}