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/*
* AM33XX PRM functions
*
* Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/io.h>
#include "common.h"
#include "prm33xx.h"
#include "prm-regbits-33xx.h"
/* Read a register in a PRM instance */
u32 am33xx_prm_read_reg(s16 inst, u16 idx)
{
return __raw_readl(prm_base + inst + idx);
}
/* Write into a register in a PRM instance */
void am33xx_prm_write_reg(u32 val, s16 inst, u16 idx)
{
__raw_writel(val, prm_base + inst + idx);
}
/* Read-modify-write a register in PRM. Caller must lock */
u32 am33xx_prm_rmw_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx)
{
u32 v;
v = am33xx_prm_read_reg(inst, idx);
v &= ~mask;
v |= bits;
am33xx_prm_write_reg(v, inst, idx);
return v;
}
/**
* am33xx_prm_is_hardreset_asserted - read the HW reset line state of
* submodules contained in the hwmod module
* @shift: register bit shift corresponding to the reset line to check
* @inst: CM instance register offset (*_INST macro)
* @rstctrl_offs: RM_RSTCTRL register address offset for this module
*
* Returns 1 if the (sub)module hardreset line is currently asserted,
* 0 if the (sub)module hardreset line is not currently asserted, or
* -EINVAL upon parameter error.
*/
int am33xx_prm_is_hardreset_asserted(u8 shift, s16 inst, u16 rstctrl_offs)
{
u32 v;
v = am33xx_prm_read_reg(inst, rstctrl_offs);
v &= 1 << shift;
v >>= shift;
return v;
}
/**
* am33xx_prm_assert_hardreset - assert the HW reset line of a submodule
* @shift: register bit shift corresponding to the reset line to assert
* @inst: CM instance register offset (*_INST macro)
* @rstctrl_reg: RM_RSTCTRL register address for this module
*
* Some IPs like dsp, ipu 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 am33xx_prm_assert_hardreset(u8 shift, s16 inst, u16 rstctrl_offs)
{
u32 mask = 1 << shift;
am33xx_prm_rmw_reg_bits(mask, mask, inst, rstctrl_offs);
return 0;
}
/**
* am33xx_prm_deassert_hardreset - deassert a submodule hardreset line and
* wait
* @shift: register bit shift corresponding to the reset line to deassert
* @inst: CM instance register offset (*_INST macro)
* @rstctrl_reg: RM_RSTCTRL register address for this module
* @rstst_reg: RM_RSTST register address for this module
*
* Some IPs like dsp, ipu 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 am33xx_prm_deassert_hardreset(u8 shift, s16 inst,
u16 rstctrl_offs, u16 rstst_offs)
{
int c;
u32 mask = 1 << shift;
/* Check the current status to avoid de-asserting the line twice */
if (am33xx_prm_is_hardreset_asserted(shift, inst, rstctrl_offs) == 0)
return -EEXIST;
/* Clear the reset status by writing 1 to the status bit */
am33xx_prm_rmw_reg_bits(0xffffffff, mask, inst, rstst_offs);
/* de-assert the reset control line */
am33xx_prm_rmw_reg_bits(mask, 0, inst, rstctrl_offs);
/* wait the status to be set */
omap_test_timeout(am33xx_prm_is_hardreset_asserted(shift, inst,
rstst_offs),
MAX_MODULE_HARDRESET_WAIT, c);
return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
}
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