/*
 * 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 <linux/irq.h>

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

#include "vp.h"

#include "prm2xxx_3xxx.h"
#include "cm2xxx_3xxx.h"
#include "prm-regbits-24xx.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			= INT_34XX_PRCM_MPU_IRQ,
	.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,
};

u32 omap2_prm_read_mod_reg(s16 module, u16 idx)
{
	return __raw_readl(prm_base + module + idx);
}

void omap2_prm_write_mod_reg(u32 val, s16 module, u16 idx)
{
	__raw_writel(val, prm_base + module + idx);
}

/* Read-modify-write a register in a PRM module. Caller must lock */
u32 omap2_prm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx)
{
	u32 v;

	v = omap2_prm_read_mod_reg(module, idx);
	v &= ~mask;
	v |= bits;
	omap2_prm_write_mod_reg(v, module, idx);

	return v;
}

/* Read a PRM register, AND it, and shift the result down to bit 0 */
u32 omap2_prm_read_mod_bits_shift(s16 domain, s16 idx, u32 mask)
{
	u32 v;

	v = omap2_prm_read_mod_reg(domain, idx);
	v &= mask;
	v >>= __ffs(mask);

	return v;
}

u32 omap2_prm_set_mod_reg_bits(u32 bits, s16 module, s16 idx)
{
	return omap2_prm_rmw_mod_reg_bits(bits, bits, module, idx);
}

u32 omap2_prm_clear_mod_reg_bits(u32 bits, s16 module, s16 idx)
{
	return omap2_prm_rmw_mod_reg_bits(bits, 0x0, module, idx);
}


/**
 * 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)
{
	if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
		return -EINVAL;

	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;

	if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
		return -EINVAL;

	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;

	if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
		return -EINVAL;

	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;
}

/* 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_prcm_init(void)
{
	if (cpu_is_omap34xx()) {
		omap3xxx_prm_enable_io_wakeup();
		return omap_prcm_register_chain_handler(&omap3_prcm_irq_setup);
	}

	return 0;
}
subsys_initcall(omap3xxx_prcm_init);