// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2021 MediaTek Inc.

#include <linux/clk.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/spmi.h>

#define SWINF_IDLE	0x00
#define SWINF_WFVLDCLR	0x06

#define GET_SWINF(x)	(((x) >> 1) & 0x7)

#define PMIF_CMD_REG_0		0
#define PMIF_CMD_REG		1
#define PMIF_CMD_EXT_REG	2
#define PMIF_CMD_EXT_REG_LONG	3

#define PMIF_DELAY_US   10
#define PMIF_TIMEOUT_US (10 * 1000)

#define PMIF_CHAN_OFFSET 0x5

#define PMIF_MAX_CLKS	3

#define SPMI_OP_ST_BUSY 1

struct ch_reg {
	u32 ch_sta;
	u32 wdata;
	u32 rdata;
	u32 ch_send;
	u32 ch_rdy;
};

struct pmif_data {
	const u32	*regs;
	const u32	*spmimst_regs;
	u32	soc_chan;
};

struct pmif {
	void __iomem	*base;
	void __iomem	*spmimst_base;
	raw_spinlock_t	lock;
	struct ch_reg	chan;
	struct clk_bulk_data clks[PMIF_MAX_CLKS];
	u32 nclks;
	const struct pmif_data *data;
};

static const char * const pmif_clock_names[] = {
	"pmif_sys_ck", "pmif_tmr_ck", "spmimst_clk_mux",
};

enum pmif_regs {
	PMIF_INIT_DONE,
	PMIF_INF_EN,
	PMIF_ARB_EN,
	PMIF_CMDISSUE_EN,
	PMIF_TIMER_CTRL,
	PMIF_SPI_MODE_CTRL,
	PMIF_IRQ_EVENT_EN_0,
	PMIF_IRQ_FLAG_0,
	PMIF_IRQ_CLR_0,
	PMIF_IRQ_EVENT_EN_1,
	PMIF_IRQ_FLAG_1,
	PMIF_IRQ_CLR_1,
	PMIF_IRQ_EVENT_EN_2,
	PMIF_IRQ_FLAG_2,
	PMIF_IRQ_CLR_2,
	PMIF_IRQ_EVENT_EN_3,
	PMIF_IRQ_FLAG_3,
	PMIF_IRQ_CLR_3,
	PMIF_IRQ_EVENT_EN_4,
	PMIF_IRQ_FLAG_4,
	PMIF_IRQ_CLR_4,
	PMIF_WDT_EVENT_EN_0,
	PMIF_WDT_FLAG_0,
	PMIF_WDT_EVENT_EN_1,
	PMIF_WDT_FLAG_1,
	PMIF_SWINF_0_STA,
	PMIF_SWINF_0_WDATA_31_0,
	PMIF_SWINF_0_RDATA_31_0,
	PMIF_SWINF_0_ACC,
	PMIF_SWINF_0_VLD_CLR,
	PMIF_SWINF_1_STA,
	PMIF_SWINF_1_WDATA_31_0,
	PMIF_SWINF_1_RDATA_31_0,
	PMIF_SWINF_1_ACC,
	PMIF_SWINF_1_VLD_CLR,
	PMIF_SWINF_2_STA,
	PMIF_SWINF_2_WDATA_31_0,
	PMIF_SWINF_2_RDATA_31_0,
	PMIF_SWINF_2_ACC,
	PMIF_SWINF_2_VLD_CLR,
	PMIF_SWINF_3_STA,
	PMIF_SWINF_3_WDATA_31_0,
	PMIF_SWINF_3_RDATA_31_0,
	PMIF_SWINF_3_ACC,
	PMIF_SWINF_3_VLD_CLR,
};

static const u32 mt6873_regs[] = {
	[PMIF_INIT_DONE] =	0x0000,
	[PMIF_INF_EN] =		0x0024,
	[PMIF_ARB_EN] =		0x0150,
	[PMIF_CMDISSUE_EN] =	0x03B4,
	[PMIF_TIMER_CTRL] =	0x03E0,
	[PMIF_SPI_MODE_CTRL] =	0x0400,
	[PMIF_IRQ_EVENT_EN_0] =	0x0418,
	[PMIF_IRQ_FLAG_0] =	0x0420,
	[PMIF_IRQ_CLR_0] =	0x0424,
	[PMIF_IRQ_EVENT_EN_1] =	0x0428,
	[PMIF_IRQ_FLAG_1] =	0x0430,
	[PMIF_IRQ_CLR_1] =	0x0434,
	[PMIF_IRQ_EVENT_EN_2] =	0x0438,
	[PMIF_IRQ_FLAG_2] =	0x0440,
	[PMIF_IRQ_CLR_2] =	0x0444,
	[PMIF_IRQ_EVENT_EN_3] =	0x0448,
	[PMIF_IRQ_FLAG_3] =	0x0450,
	[PMIF_IRQ_CLR_3] =	0x0454,
	[PMIF_IRQ_EVENT_EN_4] =	0x0458,
	[PMIF_IRQ_FLAG_4] =	0x0460,
	[PMIF_IRQ_CLR_4] =	0x0464,
	[PMIF_WDT_EVENT_EN_0] =	0x046C,
	[PMIF_WDT_FLAG_0] =	0x0470,
	[PMIF_WDT_EVENT_EN_1] =	0x0474,
	[PMIF_WDT_FLAG_1] =	0x0478,
	[PMIF_SWINF_0_ACC] =	0x0C00,
	[PMIF_SWINF_0_WDATA_31_0] =	0x0C04,
	[PMIF_SWINF_0_RDATA_31_0] =	0x0C14,
	[PMIF_SWINF_0_VLD_CLR] =	0x0C24,
	[PMIF_SWINF_0_STA] =	0x0C28,
	[PMIF_SWINF_1_ACC] =	0x0C40,
	[PMIF_SWINF_1_WDATA_31_0] =	0x0C44,
	[PMIF_SWINF_1_RDATA_31_0] =	0x0C54,
	[PMIF_SWINF_1_VLD_CLR] =	0x0C64,
	[PMIF_SWINF_1_STA] =	0x0C68,
	[PMIF_SWINF_2_ACC] =	0x0C80,
	[PMIF_SWINF_2_WDATA_31_0] =	0x0C84,
	[PMIF_SWINF_2_RDATA_31_0] =	0x0C94,
	[PMIF_SWINF_2_VLD_CLR] =	0x0CA4,
	[PMIF_SWINF_2_STA] =	0x0CA8,
	[PMIF_SWINF_3_ACC] =	0x0CC0,
	[PMIF_SWINF_3_WDATA_31_0] =	0x0CC4,
	[PMIF_SWINF_3_RDATA_31_0] =	0x0CD4,
	[PMIF_SWINF_3_VLD_CLR] =	0x0CE4,
	[PMIF_SWINF_3_STA] =	0x0CE8,
};

enum spmi_regs {
	SPMI_OP_ST_CTRL,
	SPMI_GRP_ID_EN,
	SPMI_OP_ST_STA,
	SPMI_MST_SAMPL,
	SPMI_MST_REQ_EN,
	SPMI_REC_CTRL,
	SPMI_REC0,
	SPMI_REC1,
	SPMI_REC2,
	SPMI_REC3,
	SPMI_REC4,
	SPMI_MST_DBG,
};

static const u32 mt6873_spmi_regs[] = {
	[SPMI_OP_ST_CTRL] =	0x0000,
	[SPMI_GRP_ID_EN] =	0x0004,
	[SPMI_OP_ST_STA] =	0x0008,
	[SPMI_MST_SAMPL] =	0x000c,
	[SPMI_MST_REQ_EN] =	0x0010,
	[SPMI_REC_CTRL] =	0x0040,
	[SPMI_REC0] =		0x0044,
	[SPMI_REC1] =		0x0048,
	[SPMI_REC2] =		0x004c,
	[SPMI_REC3] =		0x0050,
	[SPMI_REC4] =		0x0054,
	[SPMI_MST_DBG] =	0x00fc,
};

static u32 pmif_readl(struct pmif *arb, enum pmif_regs reg)
{
	return readl(arb->base + arb->data->regs[reg]);
}

static void pmif_writel(struct pmif *arb, u32 val, enum pmif_regs reg)
{
	writel(val, arb->base + arb->data->regs[reg]);
}

static void mtk_spmi_writel(struct pmif *arb, u32 val, enum spmi_regs reg)
{
	writel(val, arb->spmimst_base + arb->data->spmimst_regs[reg]);
}

static bool pmif_is_fsm_vldclr(struct pmif *arb)
{
	u32 reg_rdata;

	reg_rdata = pmif_readl(arb, arb->chan.ch_sta);
	return GET_SWINF(reg_rdata) == SWINF_WFVLDCLR;
}

static int pmif_arb_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid)
{
	struct pmif *arb = spmi_controller_get_drvdata(ctrl);
	u32 rdata, cmd;
	int ret;

	/* Check for argument validation. */
	if (sid & ~0xf) {
		dev_err(&ctrl->dev, "exceed the max slv id\n");
		return -EINVAL;
	}

	/* Check the opcode */
	if (opc < SPMI_CMD_RESET || opc > SPMI_CMD_WAKEUP)
		return -EINVAL;

	cmd = opc - SPMI_CMD_RESET;

	mtk_spmi_writel(arb, (cmd << 0x4) | sid, SPMI_OP_ST_CTRL);
	ret = readl_poll_timeout_atomic(arb->spmimst_base + arb->data->spmimst_regs[SPMI_OP_ST_STA],
					rdata, (rdata & SPMI_OP_ST_BUSY) == SPMI_OP_ST_BUSY,
					PMIF_DELAY_US, PMIF_TIMEOUT_US);
	if (ret < 0)
		dev_err(&ctrl->dev, "timeout, err = %d\n", ret);

	return ret;
}

static int pmif_spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
			      u16 addr, u8 *buf, size_t len)
{
	struct pmif *arb = spmi_controller_get_drvdata(ctrl);
	struct ch_reg *inf_reg;
	int ret;
	u32 data, cmd;
	unsigned long flags;

	/* Check for argument validation. */
	if (sid & ~0xf) {
		dev_err(&ctrl->dev, "exceed the max slv id\n");
		return -EINVAL;
	}

	if (len > 4) {
		dev_err(&ctrl->dev, "pmif supports 1..4 bytes per trans, but:%zu requested", len);
		return -EINVAL;
	}

	if (opc >= 0x60 && opc <= 0x7f)
		opc = PMIF_CMD_REG;
	else if ((opc >= 0x20 && opc <= 0x2f) || (opc >= 0x38 && opc <= 0x3f))
		opc = PMIF_CMD_EXT_REG_LONG;
	else
		return -EINVAL;

	raw_spin_lock_irqsave(&arb->lock, flags);

	/* Wait for Software Interface FSM state to be IDLE. */
	inf_reg = &arb->chan;
	ret = readl_poll_timeout_atomic(arb->base + arb->data->regs[inf_reg->ch_sta],
					data, GET_SWINF(data) == SWINF_IDLE,
					PMIF_DELAY_US, PMIF_TIMEOUT_US);
	if (ret < 0) {
		/* set channel ready if the data has transferred */
		if (pmif_is_fsm_vldclr(arb))
			pmif_writel(arb, 1, inf_reg->ch_rdy);
		dev_err(&ctrl->dev, "failed to wait for SWINF_IDLE\n");
		goto out;
	}

	/* Send the command. */
	cmd = (opc << 30) | (sid << 24) | ((len - 1) << 16) | addr;
	pmif_writel(arb, cmd, inf_reg->ch_send);

	/*
	 * Wait for Software Interface FSM state to be WFVLDCLR,
	 * read the data and clear the valid flag.
	 */
	ret = readl_poll_timeout_atomic(arb->base + arb->data->regs[inf_reg->ch_sta],
					data, GET_SWINF(data) == SWINF_WFVLDCLR,
					PMIF_DELAY_US, PMIF_TIMEOUT_US);
	if (ret < 0) {
		dev_err(&ctrl->dev, "failed to wait for SWINF_WFVLDCLR\n");
		goto out;
	}

	data = pmif_readl(arb, inf_reg->rdata);
	memcpy(buf, &data, len);
	pmif_writel(arb, 1, inf_reg->ch_rdy);

out:
	raw_spin_unlock_irqrestore(&arb->lock, flags);
	if (ret < 0)
		return ret;

	return 0;
}

static int pmif_spmi_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
			       u16 addr, const u8 *buf, size_t len)
{
	struct pmif *arb = spmi_controller_get_drvdata(ctrl);
	struct ch_reg *inf_reg;
	int ret;
	u32 data, cmd;
	unsigned long flags;

	/* Check for argument validation. */
	if (sid & ~0xf) {
		dev_err(&ctrl->dev, "exceed the max slv id\n");
		return -EINVAL;
	}

	if (len > 4) {
		dev_err(&ctrl->dev, "pmif supports 1..4 bytes per trans, but:%zu requested", len);
		return -EINVAL;
	}

	/* Check the opcode */
	if (opc >= 0x40 && opc <= 0x5F)
		opc = PMIF_CMD_REG;
	else if ((opc <= 0xF) || (opc >= 0x30 && opc <= 0x37))
		opc = PMIF_CMD_EXT_REG_LONG;
	else if (opc >= 0x80)
		opc = PMIF_CMD_REG_0;
	else
		return -EINVAL;

	raw_spin_lock_irqsave(&arb->lock, flags);

	/* Wait for Software Interface FSM state to be IDLE. */
	inf_reg = &arb->chan;
	ret = readl_poll_timeout_atomic(arb->base + arb->data->regs[inf_reg->ch_sta],
					data, GET_SWINF(data) == SWINF_IDLE,
					PMIF_DELAY_US, PMIF_TIMEOUT_US);
	if (ret < 0) {
		/* set channel ready if the data has transferred */
		if (pmif_is_fsm_vldclr(arb))
			pmif_writel(arb, 1, inf_reg->ch_rdy);
		dev_err(&ctrl->dev, "failed to wait for SWINF_IDLE\n");
		goto out;
	}

	/* Set the write data. */
	memcpy(&data, buf, len);
	pmif_writel(arb, data, inf_reg->wdata);

	/* Send the command. */
	cmd = (opc << 30) | BIT(29) | (sid << 24) | ((len - 1) << 16) | addr;
	pmif_writel(arb, cmd, inf_reg->ch_send);

out:
	raw_spin_unlock_irqrestore(&arb->lock, flags);
	if (ret < 0)
		return ret;

	return 0;
}

static const struct pmif_data mt6873_pmif_arb = {
	.regs = mt6873_regs,
	.spmimst_regs = mt6873_spmi_regs,
	.soc_chan = 2,
};

static int mtk_spmi_probe(struct platform_device *pdev)
{
	struct pmif *arb;
	struct spmi_controller *ctrl;
	int err, i;
	u32 chan_offset;

	ctrl = spmi_controller_alloc(&pdev->dev, sizeof(*arb));
	if (!ctrl)
		return -ENOMEM;

	arb = spmi_controller_get_drvdata(ctrl);
	arb->data = of_device_get_match_data(&pdev->dev);
	if (!arb->data) {
		err = -EINVAL;
		dev_err(&pdev->dev, "Cannot get drv_data\n");
		goto err_put_ctrl;
	}

	arb->base = devm_platform_ioremap_resource_byname(pdev, "pmif");
	if (IS_ERR(arb->base)) {
		err = PTR_ERR(arb->base);
		dev_err(&pdev->dev, "pmif failed to get the remappped memory\n");
		goto err_put_ctrl;
	}

	arb->spmimst_base = devm_platform_ioremap_resource_byname(pdev, "spmimst");
	if (IS_ERR(arb->spmimst_base)) {
		err = PTR_ERR(arb->spmimst_base);
		dev_err(&pdev->dev, "spmimst failed to get the remappped memory\n");
		goto err_put_ctrl;
	}

	arb->nclks = ARRAY_SIZE(pmif_clock_names);
	if (arb->nclks > PMIF_MAX_CLKS) {
		err = -EINVAL;
		dev_err(&pdev->dev, "exceed the max clock numbers\n");
		goto err_put_ctrl;
	}

	for (i = 0; i < arb->nclks; i++)
		arb->clks[i].id = pmif_clock_names[i];

	err = devm_clk_bulk_get(&pdev->dev, arb->nclks, arb->clks);
	if (err) {
		dev_err(&pdev->dev, "Failed to get clocks: %d\n", err);
		goto err_put_ctrl;
	}

	err = clk_bulk_prepare_enable(arb->nclks, arb->clks);
	if (err) {
		dev_err(&pdev->dev, "Failed to enable clocks: %d\n", err);
		goto err_put_ctrl;
	}

	ctrl->cmd = pmif_arb_cmd;
	ctrl->read_cmd = pmif_spmi_read_cmd;
	ctrl->write_cmd = pmif_spmi_write_cmd;

	chan_offset = PMIF_CHAN_OFFSET * arb->data->soc_chan;
	arb->chan.ch_sta = PMIF_SWINF_0_STA + chan_offset;
	arb->chan.wdata = PMIF_SWINF_0_WDATA_31_0 + chan_offset;
	arb->chan.rdata = PMIF_SWINF_0_RDATA_31_0 + chan_offset;
	arb->chan.ch_send = PMIF_SWINF_0_ACC + chan_offset;
	arb->chan.ch_rdy = PMIF_SWINF_0_VLD_CLR + chan_offset;

	raw_spin_lock_init(&arb->lock);

	platform_set_drvdata(pdev, ctrl);

	err = spmi_controller_add(ctrl);
	if (err)
		goto err_domain_remove;

	return 0;

err_domain_remove:
	clk_bulk_disable_unprepare(arb->nclks, arb->clks);
err_put_ctrl:
	spmi_controller_put(ctrl);
	return err;
}

static int mtk_spmi_remove(struct platform_device *pdev)
{
	struct spmi_controller *ctrl = platform_get_drvdata(pdev);
	struct pmif *arb = spmi_controller_get_drvdata(ctrl);

	clk_bulk_disable_unprepare(arb->nclks, arb->clks);
	spmi_controller_remove(ctrl);
	spmi_controller_put(ctrl);
	return 0;
}

static const struct of_device_id mtk_spmi_match_table[] = {
	{
		.compatible = "mediatek,mt6873-spmi",
		.data = &mt6873_pmif_arb,
	}, {
		/* sentinel */
	},
};
MODULE_DEVICE_TABLE(of, mtk_spmi_match_table);

static struct platform_driver mtk_spmi_driver = {
	.driver		= {
		.name	= "spmi-mtk",
		.of_match_table = of_match_ptr(mtk_spmi_match_table),
	},
	.probe		= mtk_spmi_probe,
	.remove		= mtk_spmi_remove,
};
module_platform_driver(mtk_spmi_driver);

MODULE_AUTHOR("Hsin-Hsiung Wang <hsin-hsiung.wang@mediatek.com>");
MODULE_DESCRIPTION("MediaTek SPMI Driver");
MODULE_LICENSE("GPL");