linux/arch/arm/mach-omap2/prm44xx.c
Tero Kristo 91285b6fa2 ARM: OMAP: PRCM: add suspend prepare / finish support
PRCM chain handler needs to disable forwarding of interrupts during
suspend, because runtime PM is disabled and most of the drivers
are potentially not able to handle interrupts coming at this time.

This patch masks all the PRCM interrupt events if a PRCM interrupt
occurs during suspend, but does not ack them. Once suspend finish
is called, all the masked events will be re-enabled, which causes
immediate PRCM interrupt and handles the postponed event.

The suspend prepare and complete  callbacks will be called from
pm34xx.c / pm44xx.c files in the following patches.

The functions defined in this patch should eventually be moved to
suspend->prepare and suspend->finish driver hooks, once the PRCM
chain handler will be made as its own driver.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
[paul@pwsan.com: add kerneldoc, add omap_prcm_irq_setup.saved_mask, add fn
 ptrs for save_and_clear_irqen() and restore_irqen()]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2011-12-16 14:36:58 -07:00

213 lines
6.1 KiB
C

/*
* OMAP4 PRM module functions
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2010 Nokia Corporation
* BenoƮt 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/delay.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/io.h>
#include <plat/common.h>
#include <plat/cpu.h>
#include <plat/prcm.h>
#include "vp.h"
#include "prm44xx.h"
#include "prm-regbits-44xx.h"
#include "prcm44xx.h"
#include "prminst44xx.h"
/* PRM low-level functions */
/* Read a register in a CM/PRM instance in the PRM module */
u32 omap4_prm_read_inst_reg(s16 inst, u16 reg)
{
return __raw_readl(OMAP44XX_PRM_REGADDR(inst, reg));
}
/* Write into a register in a CM/PRM instance in the PRM module */
void omap4_prm_write_inst_reg(u32 val, s16 inst, u16 reg)
{
__raw_writel(val, OMAP44XX_PRM_REGADDR(inst, reg));
}
/* Read-modify-write a register in a PRM module. Caller must lock */
u32 omap4_prm_rmw_inst_reg_bits(u32 mask, u32 bits, s16 inst, s16 reg)
{
u32 v;
v = omap4_prm_read_inst_reg(inst, reg);
v &= ~mask;
v |= bits;
omap4_prm_write_inst_reg(v, inst, reg);
return v;
}
/* PRM VP */
/*
* struct omap4_vp - OMAP4 VP register access description.
* @irqstatus_mpu: offset to IRQSTATUS_MPU register for VP
* @tranxdone_status: VP_TRANXDONE_ST bitmask in PRM_IRQSTATUS_MPU reg
*/
struct omap4_vp {
u32 irqstatus_mpu;
u32 tranxdone_status;
};
static struct omap4_vp omap4_vp[] = {
[OMAP4_VP_VDD_MPU_ID] = {
.irqstatus_mpu = OMAP4_PRM_IRQSTATUS_MPU_2_OFFSET,
.tranxdone_status = OMAP4430_VP_MPU_TRANXDONE_ST_MASK,
},
[OMAP4_VP_VDD_IVA_ID] = {
.irqstatus_mpu = OMAP4_PRM_IRQSTATUS_MPU_OFFSET,
.tranxdone_status = OMAP4430_VP_IVA_TRANXDONE_ST_MASK,
},
[OMAP4_VP_VDD_CORE_ID] = {
.irqstatus_mpu = OMAP4_PRM_IRQSTATUS_MPU_OFFSET,
.tranxdone_status = OMAP4430_VP_CORE_TRANXDONE_ST_MASK,
},
};
u32 omap4_prm_vp_check_txdone(u8 vp_id)
{
struct omap4_vp *vp = &omap4_vp[vp_id];
u32 irqstatus;
irqstatus = omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
OMAP4430_PRM_OCP_SOCKET_INST,
vp->irqstatus_mpu);
return irqstatus & vp->tranxdone_status;
}
void omap4_prm_vp_clear_txdone(u8 vp_id)
{
struct omap4_vp *vp = &omap4_vp[vp_id];
omap4_prminst_write_inst_reg(vp->tranxdone_status,
OMAP4430_PRM_PARTITION,
OMAP4430_PRM_OCP_SOCKET_INST,
vp->irqstatus_mpu);
};
u32 omap4_prm_vcvp_read(u8 offset)
{
return omap4_prminst_read_inst_reg(OMAP4430_PRM_PARTITION,
OMAP4430_PRM_DEVICE_INST, offset);
}
void omap4_prm_vcvp_write(u32 val, u8 offset)
{
omap4_prminst_write_inst_reg(val, OMAP4430_PRM_PARTITION,
OMAP4430_PRM_DEVICE_INST, offset);
}
u32 omap4_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset)
{
return omap4_prminst_rmw_inst_reg_bits(mask, bits,
OMAP4430_PRM_PARTITION,
OMAP4430_PRM_DEVICE_INST,
offset);
}
static inline u32 _read_pending_irq_reg(u16 irqen_offs, u16 irqst_offs)
{
u32 mask, st;
/* XXX read mask from RAM? */
mask = omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST, irqen_offs);
st = omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST, irqst_offs);
return mask & st;
}
/**
* omap44xx_prm_read_pending_irqs - read pending PRM MPU IRQs into @events
* @events: ptr to two consecutive u32s, preallocated by caller
*
* Read PRM_IRQSTATUS_MPU* bits, AND'ed with the currently-enabled PRM
* MPU IRQs, and store the result into the two u32s pointed to by @events.
* No return value.
*/
void omap44xx_prm_read_pending_irqs(unsigned long *events)
{
events[0] = _read_pending_irq_reg(OMAP4_PRM_IRQENABLE_MPU_OFFSET,
OMAP4_PRM_IRQSTATUS_MPU_OFFSET);
events[1] = _read_pending_irq_reg(OMAP4_PRM_IRQENABLE_MPU_2_OFFSET,
OMAP4_PRM_IRQSTATUS_MPU_2_OFFSET);
}
/**
* omap44xx_prm_ocp_barrier - force buffered MPU writes to the PRM to complete
*
* Force any buffered writes to the PRM IP block to complete. Needed
* by the PRM IRQ handler, which reads and writes directly to the IP
* block, to avoid race conditions after acknowledging or clearing IRQ
* bits. No return value.
*/
void omap44xx_prm_ocp_barrier(void)
{
omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
OMAP4_REVISION_PRM_OFFSET);
}
/**
* omap44xx_prm_save_and_clear_irqen - save/clear PRM_IRQENABLE_MPU* regs
* @saved_mask: ptr to a u32 array to save IRQENABLE bits
*
* Save the PRM_IRQENABLE_MPU and PRM_IRQENABLE_MPU_2 registers to
* @saved_mask. @saved_mask must be allocated by the caller.
* Intended to be used in the PRM interrupt handler suspend callback.
* The OCP barrier is needed to ensure the write to disable PRM
* interrupts reaches the PRM before returning; otherwise, spurious
* interrupts might occur. No return value.
*/
void omap44xx_prm_save_and_clear_irqen(u32 *saved_mask)
{
saved_mask[0] =
omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
OMAP4_PRM_IRQSTATUS_MPU_OFFSET);
saved_mask[1] =
omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
OMAP4_PRM_IRQSTATUS_MPU_2_OFFSET);
omap4_prm_write_inst_reg(0, OMAP4430_PRM_DEVICE_INST,
OMAP4_PRM_IRQENABLE_MPU_OFFSET);
omap4_prm_write_inst_reg(0, OMAP4430_PRM_DEVICE_INST,
OMAP4_PRM_IRQENABLE_MPU_2_OFFSET);
/* OCP barrier */
omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
OMAP4_REVISION_PRM_OFFSET);
}
/**
* omap44xx_prm_restore_irqen - set PRM_IRQENABLE_MPU* registers from args
* @saved_mask: ptr to a u32 array of IRQENABLE bits saved previously
*
* Restore the PRM_IRQENABLE_MPU and PRM_IRQENABLE_MPU_2 registers from
* @saved_mask. Intended to be used in the PRM interrupt handler resume
* callback to restore values saved by omap44xx_prm_save_and_clear_irqen().
* No OCP barrier should be needed here; any pending PRM interrupts will fire
* once the writes reach the PRM. No return value.
*/
void omap44xx_prm_restore_irqen(u32 *saved_mask)
{
omap4_prm_write_inst_reg(saved_mask[0], OMAP4430_PRM_DEVICE_INST,
OMAP4_PRM_IRQENABLE_MPU_OFFSET);
omap4_prm_write_inst_reg(saved_mask[1], OMAP4430_PRM_DEVICE_INST,
OMAP4_PRM_IRQENABLE_MPU_2_OFFSET);
}