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linux-next/arch/arm/mach-omap2/prm2xxx_3xxx.c
Paul Walmsley 9249387019 ARM: OMAP2+: clockdomain: convert existing atomic usecounts into spinlock-protected shorts/ints
The atomic usecounts seem to be confusing, and are no longer needed
since the operations that they are attached to really should take
place under lock.  Replace the atomic counters with simple integers,
protected by the enclosing powerdomain spinlock.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
2013-01-29 14:59:58 -07:00

233 lines
6.5 KiB
C

/*
* OMAP2/3 PRM module functions
*
* Copyright (C) 2010-2011 Texas Instruments, Inc.
* Copyright (C) 2010 Nokia Corporation
* Benoît Cousson
* 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/errno.h>
#include <linux/err.h>
#include <linux/io.h>
#include "common.h"
#include "powerdomain.h"
#include "prm2xxx_3xxx.h"
#include "prm-regbits-24xx.h"
#include "clockdomain.h"
/**
* omap2_prm_is_hardreset_asserted - read the HW reset line state of
* submodules contained in the hwmod module
* @prm_mod: PRM submodule base (e.g. CORE_MOD)
* @shift: register bit shift corresponding to the reset line to check
*
* Returns 1 if the (sub)module hardreset line is currently asserted,
* 0 if the (sub)module hardreset line is not currently asserted, or
* -EINVAL if called while running on a non-OMAP2/3 chip.
*/
int omap2_prm_is_hardreset_asserted(s16 prm_mod, u8 shift)
{
return omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL,
(1 << shift));
}
/**
* omap2_prm_assert_hardreset - assert the HW reset line of a submodule
* @prm_mod: PRM submodule base (e.g. CORE_MOD)
* @shift: register bit shift corresponding to the reset line to assert
*
* Some IPs like dsp or iva contain processors that require an HW
* reset line to be asserted / deasserted in order to fully enable the
* IP. These modules may have multiple hard-reset lines that reset
* different 'submodules' inside the IP block. This function will
* place the submodule into reset. Returns 0 upon success or -EINVAL
* upon an argument error.
*/
int omap2_prm_assert_hardreset(s16 prm_mod, u8 shift)
{
u32 mask;
mask = 1 << shift;
omap2_prm_rmw_mod_reg_bits(mask, mask, prm_mod, OMAP2_RM_RSTCTRL);
return 0;
}
/**
* omap2_prm_deassert_hardreset - deassert a submodule hardreset line and wait
* @prm_mod: PRM submodule base (e.g. CORE_MOD)
* @rst_shift: register bit shift corresponding to the reset line to deassert
* @st_shift: register bit shift for the status of the deasserted submodule
*
* Some IPs like dsp or iva contain processors that require an HW
* reset line to be asserted / deasserted in order to fully enable the
* IP. These modules may have multiple hard-reset lines that reset
* different 'submodules' inside the IP block. This function will
* take the submodule out of reset and wait until the PRCM indicates
* that the reset has completed before returning. Returns 0 upon success or
* -EINVAL upon an argument error, -EEXIST if the submodule was already out
* of reset, or -EBUSY if the submodule did not exit reset promptly.
*/
int omap2_prm_deassert_hardreset(s16 prm_mod, u8 rst_shift, u8 st_shift)
{
u32 rst, st;
int c;
rst = 1 << rst_shift;
st = 1 << st_shift;
/* Check the current status to avoid de-asserting the line twice */
if (omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL, rst) == 0)
return -EEXIST;
/* Clear the reset status by writing 1 to the status bit */
omap2_prm_rmw_mod_reg_bits(0xffffffff, st, prm_mod, OMAP2_RM_RSTST);
/* de-assert the reset control line */
omap2_prm_rmw_mod_reg_bits(rst, 0, prm_mod, OMAP2_RM_RSTCTRL);
/* wait the status to be set */
omap_test_timeout(omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTST,
st),
MAX_MODULE_HARDRESET_WAIT, c);
return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
}
/* Powerdomain low-level functions */
/* Common functions across OMAP2 and OMAP3 */
int omap2_pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank,
u8 pwrst)
{
u32 m;
m = omap2_pwrdm_get_mem_bank_onstate_mask(bank);
omap2_prm_rmw_mod_reg_bits(m, (pwrst << __ffs(m)), pwrdm->prcm_offs,
OMAP2_PM_PWSTCTRL);
return 0;
}
int omap2_pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank,
u8 pwrst)
{
u32 m;
m = omap2_pwrdm_get_mem_bank_retst_mask(bank);
omap2_prm_rmw_mod_reg_bits(m, (pwrst << __ffs(m)), pwrdm->prcm_offs,
OMAP2_PM_PWSTCTRL);
return 0;
}
int omap2_pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
{
u32 m;
m = omap2_pwrdm_get_mem_bank_stst_mask(bank);
return omap2_prm_read_mod_bits_shift(pwrdm->prcm_offs, OMAP2_PM_PWSTST,
m);
}
int omap2_pwrdm_read_mem_retst(struct powerdomain *pwrdm, u8 bank)
{
u32 m;
m = omap2_pwrdm_get_mem_bank_retst_mask(bank);
return omap2_prm_read_mod_bits_shift(pwrdm->prcm_offs,
OMAP2_PM_PWSTCTRL, m);
}
int omap2_pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
{
u32 v;
v = pwrst << __ffs(OMAP_LOGICRETSTATE_MASK);
omap2_prm_rmw_mod_reg_bits(OMAP_LOGICRETSTATE_MASK, v, pwrdm->prcm_offs,
OMAP2_PM_PWSTCTRL);
return 0;
}
int omap2_pwrdm_wait_transition(struct powerdomain *pwrdm)
{
u32 c = 0;
/*
* REVISIT: pwrdm_wait_transition() may be better implemented
* via a callback and a periodic timer check -- how long do we expect
* powerdomain transitions to take?
*/
/* XXX Is this udelay() value meaningful? */
while ((omap2_prm_read_mod_reg(pwrdm->prcm_offs, OMAP2_PM_PWSTST) &
OMAP_INTRANSITION_MASK) &&
(c++ < PWRDM_TRANSITION_BAILOUT))
udelay(1);
if (c > PWRDM_TRANSITION_BAILOUT) {
pr_err("powerdomain: %s: waited too long to complete transition\n",
pwrdm->name);
return -EAGAIN;
}
pr_debug("powerdomain: completed transition in %d loops\n", c);
return 0;
}
int omap2_clkdm_add_wkdep(struct clockdomain *clkdm1,
struct clockdomain *clkdm2)
{
omap2_prm_set_mod_reg_bits((1 << clkdm2->dep_bit),
clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
return 0;
}
int omap2_clkdm_del_wkdep(struct clockdomain *clkdm1,
struct clockdomain *clkdm2)
{
omap2_prm_clear_mod_reg_bits((1 << clkdm2->dep_bit),
clkdm1->pwrdm.ptr->prcm_offs, PM_WKDEP);
return 0;
}
int omap2_clkdm_read_wkdep(struct clockdomain *clkdm1,
struct clockdomain *clkdm2)
{
return omap2_prm_read_mod_bits_shift(clkdm1->pwrdm.ptr->prcm_offs,
PM_WKDEP, (1 << clkdm2->dep_bit));
}
/* XXX Caller must hold the clkdm's powerdomain lock */
int omap2_clkdm_clear_all_wkdeps(struct clockdomain *clkdm)
{
struct clkdm_dep *cd;
u32 mask = 0;
for (cd = clkdm->wkdep_srcs; cd && cd->clkdm_name; cd++) {
if (!cd->clkdm)
continue; /* only happens if data is erroneous */
/* PRM accesses are slow, so minimize them */
mask |= 1 << cd->clkdm->dep_bit;
cd->wkdep_usecount = 0;
}
omap2_prm_clear_mod_reg_bits(mask, clkdm->pwrdm.ptr->prcm_offs,
PM_WKDEP);
return 0;
}