/*
 * Renesas RCar Gen3 CPG MSSR driver
 *
 * Copyright (C) 2018 Marek Vasut <marek.vasut@gmail.com>
 *
 * Based on the following driver from Linux kernel:
 * r8a7796 Clock Pulse Generator / Module Standby and Software Reset
 *
 * Copyright (C) 2016 Glider bvba
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */
#include <common.h>
#include <clk-uclass.h>
#include <dm.h>
#include <errno.h>
#include <wait_bit.h>
#include <asm/io.h>

#include <dt-bindings/clock/renesas-cpg-mssr.h>

#include "renesas-cpg-mssr.h"

/*
 * Module Standby and Software Reset register offets.
 *
 * If the registers exist, these are valid for SH-Mobile, R-Mobile,
 * R-Car Gen2, R-Car Gen3, and RZ/G1.
 * These are NOT valid for R-Car Gen1 and RZ/A1!
 */

/*
 * Module Stop Status Register offsets
 */

static const u16 mstpsr[] = {
	0x030, 0x038, 0x040, 0x048, 0x04C, 0x03C, 0x1C0, 0x1C4,
	0x9A0, 0x9A4, 0x9A8, 0x9AC,
};

#define	MSTPSR(i)	mstpsr[i]


/*
 * System Module Stop Control Register offsets
 */

static const u16 smstpcr[] = {
	0x130, 0x134, 0x138, 0x13C, 0x140, 0x144, 0x148, 0x14C,
	0x990, 0x994, 0x998, 0x99C,
};

#define	SMSTPCR(i)	smstpcr[i]


/* Realtime Module Stop Control Register offsets */
#define RMSTPCR(i)	(smstpcr[i] - 0x20)

/* Modem Module Stop Control Register offsets (r8a73a4) */
#define MMSTPCR(i)	(smstpcr[i] + 0x20)

/* Software Reset Clearing Register offsets */
#define	SRSTCLR(i)	(0x940 + (i) * 4)

bool renesas_clk_is_mod(struct clk *clk)
{
	return (clk->id >> 16) == CPG_MOD;
}

int renesas_clk_get_mod(struct clk *clk, struct cpg_mssr_info *info,
			const struct mssr_mod_clk **mssr)
{
	const unsigned long clkid = clk->id & 0xffff;
	int i;

	for (i = 0; i < info->mod_clk_size; i++) {
		if (info->mod_clk[i].id !=
		    (info->mod_clk_base + MOD_CLK_PACK(clkid)))
			continue;

		*mssr = &info->mod_clk[i];
		return 0;
	}

	return -ENODEV;
}

int renesas_clk_get_core(struct clk *clk, struct cpg_mssr_info *info,
			 const struct cpg_core_clk **core)
{
	const unsigned long clkid = clk->id & 0xffff;
	int i;

	for (i = 0; i < info->core_clk_size; i++) {
		if (info->core_clk[i].id != clkid)
			continue;

		*core = &info->core_clk[i];
		return 0;
	}

	return -ENODEV;
}

int renesas_clk_get_parent(struct clk *clk, struct cpg_mssr_info *info,
			   struct clk *parent)
{
	const struct cpg_core_clk *core;
	const struct mssr_mod_clk *mssr;
	int ret;

	if (renesas_clk_is_mod(clk)) {
		ret = renesas_clk_get_mod(clk, info, &mssr);
		if (ret)
			return ret;

		parent->id = mssr->parent;
	} else {
		ret = renesas_clk_get_core(clk, info, &core);
		if (ret)
			return ret;

		if (core->type == CLK_TYPE_IN)
			parent->id = ~0;	/* Top-level clock */
		else
			parent->id = core->parent;
	}

	parent->dev = clk->dev;

	return 0;
}

int renesas_clk_endisable(struct clk *clk, void __iomem *base, bool enable)
{
	const unsigned long clkid = clk->id & 0xffff;
	const unsigned int reg = clkid / 100;
	const unsigned int bit = clkid % 100;
	const u32 bitmask = BIT(bit);

	if (!renesas_clk_is_mod(clk))
		return -EINVAL;

	debug("%s[%i] MSTP %lu=%02u/%02u %s\n", __func__, __LINE__,
	      clkid, reg, bit, enable ? "ON" : "OFF");

	if (enable) {
		clrbits_le32(base + SMSTPCR(reg), bitmask);
		return wait_for_bit_le32(base + MSTPSR(reg),
				    bitmask, 0, 100, 0);
	} else {
		setbits_le32(base + SMSTPCR(reg), bitmask);
		return 0;
	}
}

int renesas_clk_remove(void __iomem *base, struct cpg_mssr_info *info)
{
	unsigned int i;

	/* Stop TMU0 */
	clrbits_le32(TMU_BASE + TSTR0, TSTR0_STR0);

	/* Stop module clock */
	for (i = 0; i < info->mstp_table_size; i++) {
		clrsetbits_le32(base + SMSTPCR(i),
				info->mstp_table[i].sdis,
				info->mstp_table[i].sen);
		clrsetbits_le32(base + RMSTPCR(i),
				info->mstp_table[i].rdis,
				info->mstp_table[i].ren);
	}

	return 0;
}
