linux/arch/arm/mach-omap2/prm2xxx_3xxx.c

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/*
* 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 "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;
}