/*
 * OMAP3xxx PRM module functions
 *
 * Copyright (C) 2010-2012 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 <linux/irq.h>

#include "common.h"
#include <plat/cpu.h>
#include <plat/prcm.h>

#include "vp.h"

#include "prm3xxx.h"
#include "cm2xxx_3xxx.h"
#include "prm-regbits-34xx.h"

static const struct omap_prcm_irq omap3_prcm_irqs[] = {
	OMAP_PRCM_IRQ("wkup",	0,	0),
	OMAP_PRCM_IRQ("io",	9,	1),
};

static struct omap_prcm_irq_setup omap3_prcm_irq_setup = {
	.ack			= OMAP3_PRM_IRQSTATUS_MPU_OFFSET,
	.mask			= OMAP3_PRM_IRQENABLE_MPU_OFFSET,
	.nr_regs		= 1,
	.irqs			= omap3_prcm_irqs,
	.nr_irqs		= ARRAY_SIZE(omap3_prcm_irqs),
	.irq			= 11 + OMAP_INTC_START,
	.read_pending_irqs	= &omap3xxx_prm_read_pending_irqs,
	.ocp_barrier		= &omap3xxx_prm_ocp_barrier,
	.save_and_clear_irqen	= &omap3xxx_prm_save_and_clear_irqen,
	.restore_irqen		= &omap3xxx_prm_restore_irqen,
};

/* PRM VP */

/*
 * struct omap3_vp - OMAP3 VP register access description.
 * @tranxdone_status: VP_TRANXDONE_ST bitmask in PRM_IRQSTATUS_MPU reg
 */
struct omap3_vp {
	u32 tranxdone_status;
};

static struct omap3_vp omap3_vp[] = {
	[OMAP3_VP_VDD_MPU_ID] = {
		.tranxdone_status = OMAP3430_VP1_TRANXDONE_ST_MASK,
	},
	[OMAP3_VP_VDD_CORE_ID] = {
		.tranxdone_status = OMAP3430_VP2_TRANXDONE_ST_MASK,
	},
};

#define MAX_VP_ID ARRAY_SIZE(omap3_vp);

u32 omap3_prm_vp_check_txdone(u8 vp_id)
{
	struct omap3_vp *vp = &omap3_vp[vp_id];
	u32 irqstatus;

	irqstatus = omap2_prm_read_mod_reg(OCP_MOD,
					   OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
	return irqstatus & vp->tranxdone_status;
}

void omap3_prm_vp_clear_txdone(u8 vp_id)
{
	struct omap3_vp *vp = &omap3_vp[vp_id];

	omap2_prm_write_mod_reg(vp->tranxdone_status,
				OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET);
}

u32 omap3_prm_vcvp_read(u8 offset)
{
	return omap2_prm_read_mod_reg(OMAP3430_GR_MOD, offset);
}

void omap3_prm_vcvp_write(u32 val, u8 offset)
{
	omap2_prm_write_mod_reg(val, OMAP3430_GR_MOD, offset);
}

u32 omap3_prm_vcvp_rmw(u32 mask, u32 bits, u8 offset)
{
	return omap2_prm_rmw_mod_reg_bits(mask, bits, OMAP3430_GR_MOD, offset);
}

/**
 * omap3xxx_prm_read_pending_irqs - read pending PRM MPU IRQs into @events
 * @events: ptr to a u32, preallocated by caller
 *
 * Read PRM_IRQSTATUS_MPU bits, AND'ed with the currently-enabled PRM
 * MPU IRQs, and store the result into the u32 pointed to by @events.
 * No return value.
 */
void omap3xxx_prm_read_pending_irqs(unsigned long *events)
{
	u32 mask, st;

	/* XXX Can the mask read be avoided (e.g., can it come from RAM?) */
	mask = omap2_prm_read_mod_reg(OCP_MOD, OMAP3_PRM_IRQENABLE_MPU_OFFSET);
	st = omap2_prm_read_mod_reg(OCP_MOD, OMAP3_PRM_IRQSTATUS_MPU_OFFSET);

	events[0] = mask & st;
}

/**
 * omap3xxx_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 omap3xxx_prm_ocp_barrier(void)
{
	omap2_prm_read_mod_reg(OCP_MOD, OMAP3_PRM_REVISION_OFFSET);
}

/**
 * omap3xxx_prm_save_and_clear_irqen - save/clear PRM_IRQENABLE_MPU reg
 * @saved_mask: ptr to a u32 array to save IRQENABLE bits
 *
 * Save the PRM_IRQENABLE_MPU register 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 omap3xxx_prm_save_and_clear_irqen(u32 *saved_mask)
{
	saved_mask[0] = omap2_prm_read_mod_reg(OCP_MOD,
					       OMAP3_PRM_IRQENABLE_MPU_OFFSET);
	omap2_prm_write_mod_reg(0, OCP_MOD, OMAP3_PRM_IRQENABLE_MPU_OFFSET);

	/* OCP barrier */
	omap2_prm_read_mod_reg(OCP_MOD, OMAP3_PRM_REVISION_OFFSET);
}

/**
 * omap3xxx_prm_restore_irqen - set PRM_IRQENABLE_MPU register from args
 * @saved_mask: ptr to a u32 array of IRQENABLE bits saved previously
 *
 * Restore the PRM_IRQENABLE_MPU register from @saved_mask.  Intended
 * to be used in the PRM interrupt handler resume callback to restore
 * values saved by omap3xxx_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 omap3xxx_prm_restore_irqen(u32 *saved_mask)
{
	omap2_prm_write_mod_reg(saved_mask[0], OCP_MOD,
				OMAP3_PRM_IRQENABLE_MPU_OFFSET);
}

/**
 * omap3xxx_prm_reconfigure_io_chain - clear latches and reconfigure I/O chain
 *
 * Clear any previously-latched I/O wakeup events and ensure that the
 * I/O wakeup gates are aligned with the current mux settings.  Works
 * by asserting WUCLKIN, waiting for WUCLKOUT to be asserted, and then
 * deasserting WUCLKIN and clearing the ST_IO_CHAIN WKST bit.  No
 * return value.
 */
void omap3xxx_prm_reconfigure_io_chain(void)
{
	int i = 0;

	omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
				   PM_WKEN);

	omap_test_timeout(omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST) &
			  OMAP3430_ST_IO_CHAIN_MASK,
			  MAX_IOPAD_LATCH_TIME, i);
	if (i == MAX_IOPAD_LATCH_TIME)
		pr_warn("PRM: I/O chain clock line assertion timed out\n");

	omap2_prm_clear_mod_reg_bits(OMAP3430_EN_IO_CHAIN_MASK, WKUP_MOD,
				     PM_WKEN);

	omap2_prm_set_mod_reg_bits(OMAP3430_ST_IO_CHAIN_MASK, WKUP_MOD,
				   PM_WKST);

	omap2_prm_read_mod_reg(WKUP_MOD, PM_WKST);
}

/**
 * omap3xxx_prm_enable_io_wakeup - enable wakeup events from I/O wakeup latches
 *
 * Activates the I/O wakeup event latches and allows events logged by
 * those latches to signal a wakeup event to the PRCM.  For I/O
 * wakeups to occur, WAKEUPENABLE bits must be set in the pad mux
 * registers, and omap3xxx_prm_reconfigure_io_chain() must be called.
 * No return value.
 */
static void __init omap3xxx_prm_enable_io_wakeup(void)
{
	if (omap3_has_io_wakeup())
		omap2_prm_set_mod_reg_bits(OMAP3430_EN_IO_MASK, WKUP_MOD,
					   PM_WKEN);
}

static int __init omap3xxx_prm_init(void)
{
	int ret;

	if (!cpu_is_omap34xx())
		return 0;

	omap3xxx_prm_enable_io_wakeup();
	ret = omap_prcm_register_chain_handler(&omap3_prcm_irq_setup);
	if (!ret)
		irq_set_status_flags(omap_prcm_event_to_irq("io"),
				     IRQ_NOAUTOEN);

	return ret;
}
subsys_initcall(omap3xxx_prm_init);