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169c82a294
am33xx_cm_wait_module_ready() checks if register offset is NULL.
int am33xx_cm_wait_module_ready(u16 inst, s16 cdoffs, u16 clkctrl_offs)
{
int i = 0;
if (!clkctrl_offs)
return 0;
In case of AM33xx, CLKCTRL register offset for different clock domains
are not uniformly placed. An example of this would be the RTC clock
domain with CLKCTRL offset at 0x00.
In such cases the module ready check is skipped which leads to a data
abort during boot-up when RTC registers is accessed.
Remove this check here to avoid checking module readiness for modules
with clkctrl register offset at 0x00.
Koen Kooi notes that this patch fixes a crash on boot with
CONFIG_RTC_DRV_OMAP=y with v3.8-rc5.
Signed-off-by: Hebbar Gururaja <gururaja.hebbar@ti.com>
Cc: Koen Kooi <koen@dominion.thruhere.net>
[paul@pwsan.com: noted Koen's test in the patch description]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
365 lines
10 KiB
C
365 lines
10 KiB
C
/*
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* AM33XX CM functions
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*
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* Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/
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* Vaibhav Hiremath <hvaibhav@ti.com>
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*
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* Reference taken from from OMAP4 cminst44xx.c
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include "clockdomain.h"
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#include "cm.h"
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#include "cm33xx.h"
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#include "cm-regbits-34xx.h"
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#include "cm-regbits-33xx.h"
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#include "prm33xx.h"
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/*
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* CLKCTRL_IDLEST_*: possible values for the CM_*_CLKCTRL.IDLEST bitfield:
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*
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* 0x0 func: Module is fully functional, including OCP
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* 0x1 trans: Module is performing transition: wakeup, or sleep, or sleep
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* abortion
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* 0x2 idle: Module is in Idle mode (only OCP part). It is functional if
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* using separate functional clock
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* 0x3 disabled: Module is disabled and cannot be accessed
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*
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*/
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#define CLKCTRL_IDLEST_FUNCTIONAL 0x0
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#define CLKCTRL_IDLEST_INTRANSITION 0x1
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#define CLKCTRL_IDLEST_INTERFACE_IDLE 0x2
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#define CLKCTRL_IDLEST_DISABLED 0x3
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/* Private functions */
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/* Read a register in a CM instance */
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static inline u32 am33xx_cm_read_reg(s16 inst, u16 idx)
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{
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return __raw_readl(cm_base + inst + idx);
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}
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/* Write into a register in a CM */
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static inline void am33xx_cm_write_reg(u32 val, s16 inst, u16 idx)
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{
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__raw_writel(val, cm_base + inst + idx);
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}
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/* Read-modify-write a register in CM */
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static inline u32 am33xx_cm_rmw_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx)
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{
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u32 v;
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v = am33xx_cm_read_reg(inst, idx);
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v &= ~mask;
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v |= bits;
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am33xx_cm_write_reg(v, inst, idx);
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return v;
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}
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static inline u32 am33xx_cm_set_reg_bits(u32 bits, s16 inst, s16 idx)
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{
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return am33xx_cm_rmw_reg_bits(bits, bits, inst, idx);
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}
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static inline u32 am33xx_cm_clear_reg_bits(u32 bits, s16 inst, s16 idx)
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{
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return am33xx_cm_rmw_reg_bits(bits, 0x0, inst, idx);
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}
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static inline u32 am33xx_cm_read_reg_bits(u16 inst, s16 idx, u32 mask)
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{
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u32 v;
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v = am33xx_cm_read_reg(inst, idx);
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v &= mask;
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v >>= __ffs(mask);
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return v;
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}
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/**
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* _clkctrl_idlest - read a CM_*_CLKCTRL register; mask & shift IDLEST bitfield
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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* @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
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*
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* Return the IDLEST bitfield of a CM_*_CLKCTRL register, shifted down to
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* bit 0.
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*/
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static u32 _clkctrl_idlest(u16 inst, s16 cdoffs, u16 clkctrl_offs)
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{
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u32 v = am33xx_cm_read_reg(inst, clkctrl_offs);
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v &= AM33XX_IDLEST_MASK;
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v >>= AM33XX_IDLEST_SHIFT;
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return v;
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}
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/**
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* _is_module_ready - can module registers be accessed without causing an abort?
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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* @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
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*
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* Returns true if the module's CM_*_CLKCTRL.IDLEST bitfield is either
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* *FUNCTIONAL or *INTERFACE_IDLE; false otherwise.
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*/
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static bool _is_module_ready(u16 inst, s16 cdoffs, u16 clkctrl_offs)
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{
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u32 v;
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v = _clkctrl_idlest(inst, cdoffs, clkctrl_offs);
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return (v == CLKCTRL_IDLEST_FUNCTIONAL ||
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v == CLKCTRL_IDLEST_INTERFACE_IDLE) ? true : false;
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}
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/**
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* _clktrctrl_write - write @c to a CM_CLKSTCTRL.CLKTRCTRL register bitfield
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* @c: CLKTRCTRL register bitfield (LSB = bit 0, i.e., unshifted)
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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*
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* @c must be the unshifted value for CLKTRCTRL - i.e., this function
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* will handle the shift itself.
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*/
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static void _clktrctrl_write(u8 c, s16 inst, u16 cdoffs)
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{
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u32 v;
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v = am33xx_cm_read_reg(inst, cdoffs);
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v &= ~AM33XX_CLKTRCTRL_MASK;
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v |= c << AM33XX_CLKTRCTRL_SHIFT;
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am33xx_cm_write_reg(v, inst, cdoffs);
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}
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/* Public functions */
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/**
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* am33xx_cm_is_clkdm_in_hwsup - is a clockdomain in hwsup idle mode?
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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*
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* Returns true if the clockdomain referred to by (@inst, @cdoffs)
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* is in hardware-supervised idle mode, or 0 otherwise.
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*/
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bool am33xx_cm_is_clkdm_in_hwsup(s16 inst, u16 cdoffs)
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{
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u32 v;
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v = am33xx_cm_read_reg(inst, cdoffs);
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v &= AM33XX_CLKTRCTRL_MASK;
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v >>= AM33XX_CLKTRCTRL_SHIFT;
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return (v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ? true : false;
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}
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/**
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* am33xx_cm_clkdm_enable_hwsup - put a clockdomain in hwsup-idle mode
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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*
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* Put a clockdomain referred to by (@inst, @cdoffs) into
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* hardware-supervised idle mode. No return value.
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*/
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void am33xx_cm_clkdm_enable_hwsup(s16 inst, u16 cdoffs)
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{
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_clktrctrl_write(OMAP34XX_CLKSTCTRL_ENABLE_AUTO, inst, cdoffs);
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}
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/**
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* am33xx_cm_clkdm_disable_hwsup - put a clockdomain in swsup-idle mode
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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*
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* Put a clockdomain referred to by (@inst, @cdoffs) into
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* software-supervised idle mode, i.e., controlled manually by the
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* Linux OMAP clockdomain code. No return value.
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*/
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void am33xx_cm_clkdm_disable_hwsup(s16 inst, u16 cdoffs)
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{
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_clktrctrl_write(OMAP34XX_CLKSTCTRL_DISABLE_AUTO, inst, cdoffs);
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}
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/**
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* am33xx_cm_clkdm_force_sleep - try to put a clockdomain into idle
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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*
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* Put a clockdomain referred to by (@inst, @cdoffs) into idle
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* No return value.
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*/
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void am33xx_cm_clkdm_force_sleep(s16 inst, u16 cdoffs)
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{
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_clktrctrl_write(OMAP34XX_CLKSTCTRL_FORCE_SLEEP, inst, cdoffs);
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}
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/**
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* am33xx_cm_clkdm_force_wakeup - try to take a clockdomain out of idle
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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*
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* Take a clockdomain referred to by (@inst, @cdoffs) out of idle,
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* waking it up. No return value.
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*/
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void am33xx_cm_clkdm_force_wakeup(s16 inst, u16 cdoffs)
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{
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_clktrctrl_write(OMAP34XX_CLKSTCTRL_FORCE_WAKEUP, inst, cdoffs);
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}
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/*
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*
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*/
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/**
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* am33xx_cm_wait_module_ready - wait for a module to be in 'func' state
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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* @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
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*
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* Wait for the module IDLEST to be functional. If the idle state is in any
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* the non functional state (trans, idle or disabled), module and thus the
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* sysconfig cannot be accessed and will probably lead to an "imprecise
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* external abort"
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*/
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int am33xx_cm_wait_module_ready(u16 inst, s16 cdoffs, u16 clkctrl_offs)
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{
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int i = 0;
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omap_test_timeout(_is_module_ready(inst, cdoffs, clkctrl_offs),
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MAX_MODULE_READY_TIME, i);
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return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
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}
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/**
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* am33xx_cm_wait_module_idle - wait for a module to be in 'disabled'
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* state
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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* @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
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*
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* Wait for the module IDLEST to be disabled. Some PRCM transition,
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* like reset assertion or parent clock de-activation must wait the
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* module to be fully disabled.
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*/
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int am33xx_cm_wait_module_idle(u16 inst, s16 cdoffs, u16 clkctrl_offs)
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{
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int i = 0;
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if (!clkctrl_offs)
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return 0;
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omap_test_timeout((_clkctrl_idlest(inst, cdoffs, clkctrl_offs) ==
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CLKCTRL_IDLEST_DISABLED),
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MAX_MODULE_READY_TIME, i);
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return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
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}
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/**
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* am33xx_cm_module_enable - Enable the modulemode inside CLKCTRL
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* @mode: Module mode (SW or HW)
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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* @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
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*
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* No return value.
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*/
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void am33xx_cm_module_enable(u8 mode, u16 inst, s16 cdoffs, u16 clkctrl_offs)
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{
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u32 v;
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v = am33xx_cm_read_reg(inst, clkctrl_offs);
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v &= ~AM33XX_MODULEMODE_MASK;
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v |= mode << AM33XX_MODULEMODE_SHIFT;
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am33xx_cm_write_reg(v, inst, clkctrl_offs);
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}
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/**
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* am33xx_cm_module_disable - Disable the module inside CLKCTRL
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* @inst: CM instance register offset (*_INST macro)
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* @cdoffs: Clockdomain register offset (*_CDOFFS macro)
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* @clkctrl_offs: Module clock control register offset (*_CLKCTRL macro)
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*
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* No return value.
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*/
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void am33xx_cm_module_disable(u16 inst, s16 cdoffs, u16 clkctrl_offs)
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{
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u32 v;
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v = am33xx_cm_read_reg(inst, clkctrl_offs);
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v &= ~AM33XX_MODULEMODE_MASK;
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am33xx_cm_write_reg(v, inst, clkctrl_offs);
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}
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/*
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* Clockdomain low-level functions
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*/
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static int am33xx_clkdm_sleep(struct clockdomain *clkdm)
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{
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am33xx_cm_clkdm_force_sleep(clkdm->cm_inst, clkdm->clkdm_offs);
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return 0;
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}
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static int am33xx_clkdm_wakeup(struct clockdomain *clkdm)
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{
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am33xx_cm_clkdm_force_wakeup(clkdm->cm_inst, clkdm->clkdm_offs);
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return 0;
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}
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static void am33xx_clkdm_allow_idle(struct clockdomain *clkdm)
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{
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am33xx_cm_clkdm_enable_hwsup(clkdm->cm_inst, clkdm->clkdm_offs);
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}
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static void am33xx_clkdm_deny_idle(struct clockdomain *clkdm)
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{
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am33xx_cm_clkdm_disable_hwsup(clkdm->cm_inst, clkdm->clkdm_offs);
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}
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static int am33xx_clkdm_clk_enable(struct clockdomain *clkdm)
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{
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if (clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)
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return am33xx_clkdm_wakeup(clkdm);
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return 0;
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}
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static int am33xx_clkdm_clk_disable(struct clockdomain *clkdm)
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{
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bool hwsup = false;
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hwsup = am33xx_cm_is_clkdm_in_hwsup(clkdm->cm_inst, clkdm->clkdm_offs);
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if (!hwsup && (clkdm->flags & CLKDM_CAN_FORCE_SLEEP))
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am33xx_clkdm_sleep(clkdm);
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return 0;
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}
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struct clkdm_ops am33xx_clkdm_operations = {
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.clkdm_sleep = am33xx_clkdm_sleep,
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.clkdm_wakeup = am33xx_clkdm_wakeup,
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.clkdm_allow_idle = am33xx_clkdm_allow_idle,
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.clkdm_deny_idle = am33xx_clkdm_deny_idle,
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.clkdm_clk_enable = am33xx_clkdm_clk_enable,
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.clkdm_clk_disable = am33xx_clkdm_clk_disable,
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};
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