// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.

#include <linux/acpi.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/dma/qcom-gpi-dma.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/soc/qcom/geni-se.h>
#include <linux/spinlock.h>

#define SE_I2C_TX_TRANS_LEN		0x26c
#define SE_I2C_RX_TRANS_LEN		0x270
#define SE_I2C_SCL_COUNTERS		0x278

#define SE_I2C_ERR  (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN |\
			M_GP_IRQ_1_EN | M_GP_IRQ_3_EN | M_GP_IRQ_4_EN)
#define SE_I2C_ABORT		BIT(1)

/* M_CMD OP codes for I2C */
#define I2C_WRITE		0x1
#define I2C_READ		0x2
#define I2C_WRITE_READ		0x3
#define I2C_ADDR_ONLY		0x4
#define I2C_BUS_CLEAR		0x6
#define I2C_STOP_ON_BUS		0x7
/* M_CMD params for I2C */
#define PRE_CMD_DELAY		BIT(0)
#define TIMESTAMP_BEFORE	BIT(1)
#define STOP_STRETCH		BIT(2)
#define TIMESTAMP_AFTER		BIT(3)
#define POST_COMMAND_DELAY	BIT(4)
#define IGNORE_ADD_NACK		BIT(6)
#define READ_FINISHED_WITH_ACK	BIT(7)
#define BYPASS_ADDR_PHASE	BIT(8)
#define SLV_ADDR_MSK		GENMASK(15, 9)
#define SLV_ADDR_SHFT		9
/* I2C SCL COUNTER fields */
#define HIGH_COUNTER_MSK	GENMASK(29, 20)
#define HIGH_COUNTER_SHFT	20
#define LOW_COUNTER_MSK		GENMASK(19, 10)
#define LOW_COUNTER_SHFT	10
#define CYCLE_COUNTER_MSK	GENMASK(9, 0)

#define I2C_PACK_TX		BIT(0)
#define I2C_PACK_RX		BIT(1)

enum geni_i2c_err_code {
	GP_IRQ0,
	NACK,
	GP_IRQ2,
	BUS_PROTO,
	ARB_LOST,
	GP_IRQ5,
	GENI_OVERRUN,
	GENI_ILLEGAL_CMD,
	GENI_ABORT_DONE,
	GENI_TIMEOUT,
};

#define DM_I2C_CB_ERR		((BIT(NACK) | BIT(BUS_PROTO) | BIT(ARB_LOST)) \
									<< 5)

#define I2C_AUTO_SUSPEND_DELAY	250
#define KHZ(freq)		(1000 * freq)
#define PACKING_BYTES_PW	4

#define ABORT_TIMEOUT		HZ
#define XFER_TIMEOUT		HZ
#define RST_TIMEOUT		HZ

struct geni_i2c_dev {
	struct geni_se se;
	u32 tx_wm;
	int irq;
	int err;
	struct i2c_adapter adap;
	struct completion done;
	struct i2c_msg *cur;
	int cur_wr;
	int cur_rd;
	spinlock_t lock;
	struct clk *core_clk;
	u32 clk_freq_out;
	const struct geni_i2c_clk_fld *clk_fld;
	int suspended;
	void *dma_buf;
	size_t xfer_len;
	dma_addr_t dma_addr;
	struct dma_chan *tx_c;
	struct dma_chan *rx_c;
	bool gpi_mode;
	bool abort_done;
};

struct geni_i2c_desc {
	bool has_core_clk;
	char *icc_ddr;
	bool no_dma_support;
	unsigned int tx_fifo_depth;
};

struct geni_i2c_err_log {
	int err;
	const char *msg;
};

static const struct geni_i2c_err_log gi2c_log[] = {
	[GP_IRQ0] = {-EIO, "Unknown I2C err GP_IRQ0"},
	[NACK] = {-ENXIO, "NACK: slv unresponsive, check its power/reset-ln"},
	[GP_IRQ2] = {-EIO, "Unknown I2C err GP IRQ2"},
	[BUS_PROTO] = {-EPROTO, "Bus proto err, noisy/unexpected start/stop"},
	[ARB_LOST] = {-EAGAIN, "Bus arbitration lost, clock line undriveable"},
	[GP_IRQ5] = {-EIO, "Unknown I2C err GP IRQ5"},
	[GENI_OVERRUN] = {-EIO, "Cmd overrun, check GENI cmd-state machine"},
	[GENI_ILLEGAL_CMD] = {-EIO, "Illegal cmd, check GENI cmd-state machine"},
	[GENI_ABORT_DONE] = {-ETIMEDOUT, "Abort after timeout successful"},
	[GENI_TIMEOUT] = {-ETIMEDOUT, "I2C TXN timed out"},
};

struct geni_i2c_clk_fld {
	u32	clk_freq_out;
	u8	clk_div;
	u8	t_high_cnt;
	u8	t_low_cnt;
	u8	t_cycle_cnt;
};

/*
 * Hardware uses the underlying formula to calculate time periods of
 * SCL clock cycle. Firmware uses some additional cycles excluded from the
 * below formula and it is confirmed that the time periods are within
 * specification limits.
 *
 * time of high period of SCL: t_high = (t_high_cnt * clk_div) / source_clock
 * time of low period of SCL: t_low = (t_low_cnt * clk_div) / source_clock
 * time of full period of SCL: t_cycle = (t_cycle_cnt * clk_div) / source_clock
 * clk_freq_out = t / t_cycle
 * source_clock = 19.2 MHz
 */
static const struct geni_i2c_clk_fld geni_i2c_clk_map[] = {
	{KHZ(100), 7, 10, 11, 26},
	{KHZ(400), 2,  5, 12, 24},
	{KHZ(1000), 1, 3,  9, 18},
};

static int geni_i2c_clk_map_idx(struct geni_i2c_dev *gi2c)
{
	int i;
	const struct geni_i2c_clk_fld *itr = geni_i2c_clk_map;

	for (i = 0; i < ARRAY_SIZE(geni_i2c_clk_map); i++, itr++) {
		if (itr->clk_freq_out == gi2c->clk_freq_out) {
			gi2c->clk_fld = itr;
			return 0;
		}
	}
	return -EINVAL;
}

static void qcom_geni_i2c_conf(struct geni_i2c_dev *gi2c)
{
	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
	u32 val;

	writel_relaxed(0, gi2c->se.base + SE_GENI_CLK_SEL);

	val = (itr->clk_div << CLK_DIV_SHFT) | SER_CLK_EN;
	writel_relaxed(val, gi2c->se.base + GENI_SER_M_CLK_CFG);

	val = itr->t_high_cnt << HIGH_COUNTER_SHFT;
	val |= itr->t_low_cnt << LOW_COUNTER_SHFT;
	val |= itr->t_cycle_cnt;
	writel_relaxed(val, gi2c->se.base + SE_I2C_SCL_COUNTERS);
}

static void geni_i2c_err_misc(struct geni_i2c_dev *gi2c)
{
	u32 m_cmd = readl_relaxed(gi2c->se.base + SE_GENI_M_CMD0);
	u32 m_stat = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
	u32 geni_s = readl_relaxed(gi2c->se.base + SE_GENI_STATUS);
	u32 geni_ios = readl_relaxed(gi2c->se.base + SE_GENI_IOS);
	u32 dma = readl_relaxed(gi2c->se.base + SE_GENI_DMA_MODE_EN);
	u32 rx_st, tx_st;

	if (dma) {
		rx_st = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
		tx_st = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
	} else {
		rx_st = readl_relaxed(gi2c->se.base + SE_GENI_RX_FIFO_STATUS);
		tx_st = readl_relaxed(gi2c->se.base + SE_GENI_TX_FIFO_STATUS);
	}
	dev_dbg(gi2c->se.dev, "DMA:%d tx_stat:0x%x, rx_stat:0x%x, irq-stat:0x%x\n",
		dma, tx_st, rx_st, m_stat);
	dev_dbg(gi2c->se.dev, "m_cmd:0x%x, geni_status:0x%x, geni_ios:0x%x\n",
		m_cmd, geni_s, geni_ios);
}

static void geni_i2c_err(struct geni_i2c_dev *gi2c, int err)
{
	if (!gi2c->err)
		gi2c->err = gi2c_log[err].err;
	if (gi2c->cur)
		dev_dbg(gi2c->se.dev, "len:%d, slv-addr:0x%x, RD/WR:%d\n",
			gi2c->cur->len, gi2c->cur->addr, gi2c->cur->flags);

	switch (err) {
	case GENI_ABORT_DONE:
		gi2c->abort_done = true;
		break;
	case NACK:
	case GENI_TIMEOUT:
		dev_dbg(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
		break;
	default:
		dev_err(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
		geni_i2c_err_misc(gi2c);
		break;
	}
}

static irqreturn_t geni_i2c_irq(int irq, void *dev)
{
	struct geni_i2c_dev *gi2c = dev;
	void __iomem *base = gi2c->se.base;
	int j, p;
	u32 m_stat;
	u32 rx_st;
	u32 dm_tx_st;
	u32 dm_rx_st;
	u32 dma;
	u32 val;
	struct i2c_msg *cur;

	spin_lock(&gi2c->lock);
	m_stat = readl_relaxed(base + SE_GENI_M_IRQ_STATUS);
	rx_st = readl_relaxed(base + SE_GENI_RX_FIFO_STATUS);
	dm_tx_st = readl_relaxed(base + SE_DMA_TX_IRQ_STAT);
	dm_rx_st = readl_relaxed(base + SE_DMA_RX_IRQ_STAT);
	dma = readl_relaxed(base + SE_GENI_DMA_MODE_EN);
	cur = gi2c->cur;

	if (!cur ||
	    m_stat & (M_CMD_FAILURE_EN | M_CMD_ABORT_EN) ||
	    dm_rx_st & (DM_I2C_CB_ERR)) {
		if (m_stat & M_GP_IRQ_1_EN)
			geni_i2c_err(gi2c, NACK);
		if (m_stat & M_GP_IRQ_3_EN)
			geni_i2c_err(gi2c, BUS_PROTO);
		if (m_stat & M_GP_IRQ_4_EN)
			geni_i2c_err(gi2c, ARB_LOST);
		if (m_stat & M_CMD_OVERRUN_EN)
			geni_i2c_err(gi2c, GENI_OVERRUN);
		if (m_stat & M_ILLEGAL_CMD_EN)
			geni_i2c_err(gi2c, GENI_ILLEGAL_CMD);
		if (m_stat & M_CMD_ABORT_EN)
			geni_i2c_err(gi2c, GENI_ABORT_DONE);
		if (m_stat & M_GP_IRQ_0_EN)
			geni_i2c_err(gi2c, GP_IRQ0);

		/* Disable the TX Watermark interrupt to stop TX */
		if (!dma)
			writel_relaxed(0, base + SE_GENI_TX_WATERMARK_REG);
	} else if (dma) {
		dev_dbg(gi2c->se.dev, "i2c dma tx:0x%x, dma rx:0x%x\n",
			dm_tx_st, dm_rx_st);
	} else if (cur->flags & I2C_M_RD &&
		   m_stat & (M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN)) {
		u32 rxcnt = rx_st & RX_FIFO_WC_MSK;

		for (j = 0; j < rxcnt; j++) {
			p = 0;
			val = readl_relaxed(base + SE_GENI_RX_FIFOn);
			while (gi2c->cur_rd < cur->len && p < sizeof(val)) {
				cur->buf[gi2c->cur_rd++] = val & 0xff;
				val >>= 8;
				p++;
			}
			if (gi2c->cur_rd == cur->len)
				break;
		}
	} else if (!(cur->flags & I2C_M_RD) &&
		   m_stat & M_TX_FIFO_WATERMARK_EN) {
		for (j = 0; j < gi2c->tx_wm; j++) {
			u32 temp;

			val = 0;
			p = 0;
			while (gi2c->cur_wr < cur->len && p < sizeof(val)) {
				temp = cur->buf[gi2c->cur_wr++];
				val |= temp << (p * 8);
				p++;
			}
			writel_relaxed(val, base + SE_GENI_TX_FIFOn);
			/* TX Complete, Disable the TX Watermark interrupt */
			if (gi2c->cur_wr == cur->len) {
				writel_relaxed(0, base + SE_GENI_TX_WATERMARK_REG);
				break;
			}
		}
	}

	if (m_stat)
		writel_relaxed(m_stat, base + SE_GENI_M_IRQ_CLEAR);

	if (dma && dm_tx_st)
		writel_relaxed(dm_tx_st, base + SE_DMA_TX_IRQ_CLR);
	if (dma && dm_rx_st)
		writel_relaxed(dm_rx_st, base + SE_DMA_RX_IRQ_CLR);

	/* if this is err with done-bit not set, handle that through timeout. */
	if (m_stat & M_CMD_DONE_EN || m_stat & M_CMD_ABORT_EN ||
	    dm_tx_st & TX_DMA_DONE || dm_tx_st & TX_RESET_DONE ||
	    dm_rx_st & RX_DMA_DONE || dm_rx_st & RX_RESET_DONE)
		complete(&gi2c->done);

	spin_unlock(&gi2c->lock);

	return IRQ_HANDLED;
}

static void geni_i2c_abort_xfer(struct geni_i2c_dev *gi2c)
{
	unsigned long time_left = ABORT_TIMEOUT;
	unsigned long flags;

	spin_lock_irqsave(&gi2c->lock, flags);
	geni_i2c_err(gi2c, GENI_TIMEOUT);
	gi2c->cur = NULL;
	gi2c->abort_done = false;
	geni_se_abort_m_cmd(&gi2c->se);
	spin_unlock_irqrestore(&gi2c->lock, flags);

	do {
		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
	} while (!gi2c->abort_done && time_left);

	if (!time_left)
		dev_err(gi2c->se.dev, "Timeout abort_m_cmd\n");
}

static void geni_i2c_rx_fsm_rst(struct geni_i2c_dev *gi2c)
{
	u32 val;
	unsigned long time_left = RST_TIMEOUT;

	writel_relaxed(1, gi2c->se.base + SE_DMA_RX_FSM_RST);
	do {
		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
		val = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
	} while (!(val & RX_RESET_DONE) && time_left);

	if (!(val & RX_RESET_DONE))
		dev_err(gi2c->se.dev, "Timeout resetting RX_FSM\n");
}

static void geni_i2c_tx_fsm_rst(struct geni_i2c_dev *gi2c)
{
	u32 val;
	unsigned long time_left = RST_TIMEOUT;

	writel_relaxed(1, gi2c->se.base + SE_DMA_TX_FSM_RST);
	do {
		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
		val = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
	} while (!(val & TX_RESET_DONE) && time_left);

	if (!(val & TX_RESET_DONE))
		dev_err(gi2c->se.dev, "Timeout resetting TX_FSM\n");
}

static void geni_i2c_rx_msg_cleanup(struct geni_i2c_dev *gi2c,
				     struct i2c_msg *cur)
{
	gi2c->cur_rd = 0;
	if (gi2c->dma_buf) {
		if (gi2c->err)
			geni_i2c_rx_fsm_rst(gi2c);
		geni_se_rx_dma_unprep(&gi2c->se, gi2c->dma_addr, gi2c->xfer_len);
		i2c_put_dma_safe_msg_buf(gi2c->dma_buf, cur, !gi2c->err);
	}
}

static void geni_i2c_tx_msg_cleanup(struct geni_i2c_dev *gi2c,
				     struct i2c_msg *cur)
{
	gi2c->cur_wr = 0;
	if (gi2c->dma_buf) {
		if (gi2c->err)
			geni_i2c_tx_fsm_rst(gi2c);
		geni_se_tx_dma_unprep(&gi2c->se, gi2c->dma_addr, gi2c->xfer_len);
		i2c_put_dma_safe_msg_buf(gi2c->dma_buf, cur, !gi2c->err);
	}
}

static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
				u32 m_param)
{
	dma_addr_t rx_dma = 0;
	unsigned long time_left;
	void *dma_buf;
	struct geni_se *se = &gi2c->se;
	size_t len = msg->len;
	struct i2c_msg *cur;

	dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
	if (dma_buf)
		geni_se_select_mode(se, GENI_SE_DMA);
	else
		geni_se_select_mode(se, GENI_SE_FIFO);

	writel_relaxed(len, se->base + SE_I2C_RX_TRANS_LEN);
	geni_se_setup_m_cmd(se, I2C_READ, m_param);

	if (dma_buf && geni_se_rx_dma_prep(se, dma_buf, len, &rx_dma)) {
		geni_se_select_mode(se, GENI_SE_FIFO);
		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
		dma_buf = NULL;
	} else {
		gi2c->xfer_len = len;
		gi2c->dma_addr = rx_dma;
		gi2c->dma_buf = dma_buf;
	}

	cur = gi2c->cur;
	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
	if (!time_left)
		geni_i2c_abort_xfer(gi2c);

	geni_i2c_rx_msg_cleanup(gi2c, cur);

	return gi2c->err;
}

static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
				u32 m_param)
{
	dma_addr_t tx_dma = 0;
	unsigned long time_left;
	void *dma_buf;
	struct geni_se *se = &gi2c->se;
	size_t len = msg->len;
	struct i2c_msg *cur;

	dma_buf = i2c_get_dma_safe_msg_buf(msg, 32);
	if (dma_buf)
		geni_se_select_mode(se, GENI_SE_DMA);
	else
		geni_se_select_mode(se, GENI_SE_FIFO);

	writel_relaxed(len, se->base + SE_I2C_TX_TRANS_LEN);
	geni_se_setup_m_cmd(se, I2C_WRITE, m_param);

	if (dma_buf && geni_se_tx_dma_prep(se, dma_buf, len, &tx_dma)) {
		geni_se_select_mode(se, GENI_SE_FIFO);
		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
		dma_buf = NULL;
	} else {
		gi2c->xfer_len = len;
		gi2c->dma_addr = tx_dma;
		gi2c->dma_buf = dma_buf;
	}

	if (!dma_buf) /* Get FIFO IRQ */
		writel_relaxed(1, se->base + SE_GENI_TX_WATERMARK_REG);

	cur = gi2c->cur;
	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
	if (!time_left)
		geni_i2c_abort_xfer(gi2c);

	geni_i2c_tx_msg_cleanup(gi2c, cur);

	return gi2c->err;
}

static void i2c_gpi_cb_result(void *cb, const struct dmaengine_result *result)
{
	struct geni_i2c_dev *gi2c = cb;

	if (result->result != DMA_TRANS_NOERROR) {
		dev_err(gi2c->se.dev, "DMA txn failed:%d\n", result->result);
		gi2c->err = -EIO;
	} else if (result->residue) {
		dev_dbg(gi2c->se.dev, "DMA xfer has pending: %d\n", result->residue);
	}

	complete(&gi2c->done);
}

static void geni_i2c_gpi_unmap(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
			       void *tx_buf, dma_addr_t tx_addr,
			       void *rx_buf, dma_addr_t rx_addr)
{
	if (tx_buf) {
		dma_unmap_single(gi2c->se.dev->parent, tx_addr, msg->len, DMA_TO_DEVICE);
		i2c_put_dma_safe_msg_buf(tx_buf, msg, !gi2c->err);
	}

	if (rx_buf) {
		dma_unmap_single(gi2c->se.dev->parent, rx_addr, msg->len, DMA_FROM_DEVICE);
		i2c_put_dma_safe_msg_buf(rx_buf, msg, !gi2c->err);
	}
}

static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
			struct dma_slave_config *config, dma_addr_t *dma_addr_p,
			void **buf, unsigned int op, struct dma_chan *dma_chan)
{
	struct gpi_i2c_config *peripheral;
	unsigned int flags;
	void *dma_buf;
	dma_addr_t addr;
	enum dma_data_direction map_dirn;
	enum dma_transfer_direction dma_dirn;
	struct dma_async_tx_descriptor *desc;
	int ret;

	peripheral = config->peripheral_config;

	dma_buf = i2c_get_dma_safe_msg_buf(msg, 1);
	if (!dma_buf)
		return -ENOMEM;

	if (op == I2C_WRITE)
		map_dirn = DMA_TO_DEVICE;
	else
		map_dirn = DMA_FROM_DEVICE;

	addr = dma_map_single(gi2c->se.dev->parent, dma_buf, msg->len, map_dirn);
	if (dma_mapping_error(gi2c->se.dev->parent, addr)) {
		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
		return -ENOMEM;
	}

	/* set the length as message for rx txn */
	peripheral->rx_len = msg->len;
	peripheral->op = op;

	ret = dmaengine_slave_config(dma_chan, config);
	if (ret) {
		dev_err(gi2c->se.dev, "dma config error: %d for op:%d\n", ret, op);
		goto err_config;
	}

	peripheral->set_config = 0;
	peripheral->multi_msg = true;
	flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;

	if (op == I2C_WRITE)
		dma_dirn = DMA_MEM_TO_DEV;
	else
		dma_dirn = DMA_DEV_TO_MEM;

	desc = dmaengine_prep_slave_single(dma_chan, addr, msg->len, dma_dirn, flags);
	if (!desc) {
		dev_err(gi2c->se.dev, "prep_slave_sg failed\n");
		ret = -EIO;
		goto err_config;
	}

	desc->callback_result = i2c_gpi_cb_result;
	desc->callback_param = gi2c;

	dmaengine_submit(desc);
	*buf = dma_buf;
	*dma_addr_p = addr;

	return 0;

err_config:
	dma_unmap_single(gi2c->se.dev->parent, addr, msg->len, map_dirn);
	i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
	return ret;
}

static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], int num)
{
	struct dma_slave_config config = {};
	struct gpi_i2c_config peripheral = {};
	int i, ret = 0, timeout;
	dma_addr_t tx_addr, rx_addr;
	void *tx_buf = NULL, *rx_buf = NULL;
	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;

	config.peripheral_config = &peripheral;
	config.peripheral_size = sizeof(peripheral);

	peripheral.pack_enable = I2C_PACK_TX | I2C_PACK_RX;
	peripheral.cycle_count = itr->t_cycle_cnt;
	peripheral.high_count = itr->t_high_cnt;
	peripheral.low_count = itr->t_low_cnt;
	peripheral.clk_div = itr->clk_div;
	peripheral.set_config = 1;
	peripheral.multi_msg = false;

	for (i = 0; i < num; i++) {
		gi2c->cur = &msgs[i];
		gi2c->err = 0;
		dev_dbg(gi2c->se.dev, "msg[%d].len:%d\n", i, gi2c->cur->len);

		peripheral.stretch = 0;
		if (i < num - 1)
			peripheral.stretch = 1;

		peripheral.addr = msgs[i].addr;

		ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
				    &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c);
		if (ret)
			goto err;

		if (msgs[i].flags & I2C_M_RD) {
			ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
					    &rx_addr, &rx_buf, I2C_READ, gi2c->rx_c);
			if (ret)
				goto err;

			dma_async_issue_pending(gi2c->rx_c);
		}

		dma_async_issue_pending(gi2c->tx_c);

		timeout = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
		if (!timeout) {
			dev_err(gi2c->se.dev, "I2C timeout gpi flags:%d addr:0x%x\n",
				gi2c->cur->flags, gi2c->cur->addr);
			gi2c->err = -ETIMEDOUT;
		}

		if (gi2c->err) {
			ret = gi2c->err;
			goto err;
		}

		geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
	}

	return num;

err:
	dev_err(gi2c->se.dev, "GPI transfer failed: %d\n", ret);
	dmaengine_terminate_sync(gi2c->rx_c);
	dmaengine_terminate_sync(gi2c->tx_c);
	geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
	return ret;
}

static int geni_i2c_fifo_xfer(struct geni_i2c_dev *gi2c,
			      struct i2c_msg msgs[], int num)
{
	int i, ret = 0;

	for (i = 0; i < num; i++) {
		u32 m_param = i < (num - 1) ? STOP_STRETCH : 0;

		m_param |= ((msgs[i].addr << SLV_ADDR_SHFT) & SLV_ADDR_MSK);

		gi2c->cur = &msgs[i];
		if (msgs[i].flags & I2C_M_RD)
			ret = geni_i2c_rx_one_msg(gi2c, &msgs[i], m_param);
		else
			ret = geni_i2c_tx_one_msg(gi2c, &msgs[i], m_param);

		if (ret)
			return ret;
	}

	return num;
}

static int geni_i2c_xfer(struct i2c_adapter *adap,
			 struct i2c_msg msgs[],
			 int num)
{
	struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
	int ret;

	gi2c->err = 0;
	reinit_completion(&gi2c->done);
	ret = pm_runtime_get_sync(gi2c->se.dev);
	if (ret < 0) {
		dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
		pm_runtime_put_noidle(gi2c->se.dev);
		/* Set device in suspended since resume failed */
		pm_runtime_set_suspended(gi2c->se.dev);
		return ret;
	}

	qcom_geni_i2c_conf(gi2c);

	if (gi2c->gpi_mode)
		ret = geni_i2c_gpi_xfer(gi2c, msgs, num);
	else
		ret = geni_i2c_fifo_xfer(gi2c, msgs, num);

	pm_runtime_mark_last_busy(gi2c->se.dev);
	pm_runtime_put_autosuspend(gi2c->se.dev);
	gi2c->cur = NULL;
	gi2c->err = 0;
	return ret;
}

static u32 geni_i2c_func(struct i2c_adapter *adap)
{
	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
}

static const struct i2c_algorithm geni_i2c_algo = {
	.master_xfer	= geni_i2c_xfer,
	.functionality	= geni_i2c_func,
};

#ifdef CONFIG_ACPI
static const struct acpi_device_id geni_i2c_acpi_match[] = {
	{ "QCOM0220"},
	{ },
};
MODULE_DEVICE_TABLE(acpi, geni_i2c_acpi_match);
#endif

static void release_gpi_dma(struct geni_i2c_dev *gi2c)
{
	if (gi2c->rx_c)
		dma_release_channel(gi2c->rx_c);

	if (gi2c->tx_c)
		dma_release_channel(gi2c->tx_c);
}

static int setup_gpi_dma(struct geni_i2c_dev *gi2c)
{
	int ret;

	geni_se_select_mode(&gi2c->se, GENI_GPI_DMA);
	gi2c->tx_c = dma_request_chan(gi2c->se.dev, "tx");
	if (IS_ERR(gi2c->tx_c)) {
		ret = dev_err_probe(gi2c->se.dev, PTR_ERR(gi2c->tx_c),
				    "Failed to get tx DMA ch\n");
		goto err_tx;
	}

	gi2c->rx_c = dma_request_chan(gi2c->se.dev, "rx");
	if (IS_ERR(gi2c->rx_c)) {
		ret = dev_err_probe(gi2c->se.dev, PTR_ERR(gi2c->rx_c),
				    "Failed to get rx DMA ch\n");
		goto err_rx;
	}

	dev_dbg(gi2c->se.dev, "Grabbed GPI dma channels\n");
	return 0;

err_rx:
	dma_release_channel(gi2c->tx_c);
err_tx:
	return ret;
}

static int geni_i2c_probe(struct platform_device *pdev)
{
	struct geni_i2c_dev *gi2c;
	u32 proto, tx_depth, fifo_disable;
	int ret;
	struct device *dev = &pdev->dev;
	const struct geni_i2c_desc *desc = NULL;

	gi2c = devm_kzalloc(dev, sizeof(*gi2c), GFP_KERNEL);
	if (!gi2c)
		return -ENOMEM;

	gi2c->se.dev = dev;
	gi2c->se.wrapper = dev_get_drvdata(dev->parent);
	gi2c->se.base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(gi2c->se.base))
		return PTR_ERR(gi2c->se.base);

	desc = device_get_match_data(&pdev->dev);

	if (desc && desc->has_core_clk) {
		gi2c->core_clk = devm_clk_get(dev, "core");
		if (IS_ERR(gi2c->core_clk))
			return PTR_ERR(gi2c->core_clk);
	}

	gi2c->se.clk = devm_clk_get(dev, "se");
	if (IS_ERR(gi2c->se.clk) && !has_acpi_companion(dev))
		return PTR_ERR(gi2c->se.clk);

	ret = device_property_read_u32(dev, "clock-frequency",
				       &gi2c->clk_freq_out);
	if (ret) {
		dev_info(dev, "Bus frequency not specified, default to 100kHz.\n");
		gi2c->clk_freq_out = KHZ(100);
	}

	if (has_acpi_companion(dev))
		ACPI_COMPANION_SET(&gi2c->adap.dev, ACPI_COMPANION(dev));

	gi2c->irq = platform_get_irq(pdev, 0);
	if (gi2c->irq < 0)
		return gi2c->irq;

	ret = geni_i2c_clk_map_idx(gi2c);
	if (ret) {
		dev_err(dev, "Invalid clk frequency %d Hz: %d\n",
			gi2c->clk_freq_out, ret);
		return ret;
	}

	gi2c->adap.algo = &geni_i2c_algo;
	init_completion(&gi2c->done);
	spin_lock_init(&gi2c->lock);
	platform_set_drvdata(pdev, gi2c);
	ret = devm_request_irq(dev, gi2c->irq, geni_i2c_irq, 0,
			       dev_name(dev), gi2c);
	if (ret) {
		dev_err(dev, "Request_irq failed:%d: err:%d\n",
			gi2c->irq, ret);
		return ret;
	}
	/* Disable the interrupt so that the system can enter low-power mode */
	disable_irq(gi2c->irq);
	i2c_set_adapdata(&gi2c->adap, gi2c);
	gi2c->adap.dev.parent = dev;
	gi2c->adap.dev.of_node = dev->of_node;
	strscpy(gi2c->adap.name, "Geni-I2C", sizeof(gi2c->adap.name));

	ret = geni_icc_get(&gi2c->se, desc ? desc->icc_ddr : "qup-memory");
	if (ret)
		return ret;
	/*
	 * Set the bus quota for core and cpu to a reasonable value for
	 * register access.
	 * Set quota for DDR based on bus speed.
	 */
	gi2c->se.icc_paths[GENI_TO_CORE].avg_bw = GENI_DEFAULT_BW;
	gi2c->se.icc_paths[CPU_TO_GENI].avg_bw = GENI_DEFAULT_BW;
	if (!desc || desc->icc_ddr)
		gi2c->se.icc_paths[GENI_TO_DDR].avg_bw = Bps_to_icc(gi2c->clk_freq_out);

	ret = geni_icc_set_bw(&gi2c->se);
	if (ret)
		return ret;

	ret = clk_prepare_enable(gi2c->core_clk);
	if (ret)
		return ret;

	ret = geni_se_resources_on(&gi2c->se);
	if (ret) {
		dev_err(dev, "Error turning on resources %d\n", ret);
		clk_disable_unprepare(gi2c->core_clk);
		return ret;
	}
	proto = geni_se_read_proto(&gi2c->se);
	if (proto != GENI_SE_I2C) {
		dev_err(dev, "Invalid proto %d\n", proto);
		geni_se_resources_off(&gi2c->se);
		clk_disable_unprepare(gi2c->core_clk);
		return -ENXIO;
	}

	if (desc && desc->no_dma_support)
		fifo_disable = false;
	else
		fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE;

	if (fifo_disable) {
		/* FIFO is disabled, so we can only use GPI DMA */
		gi2c->gpi_mode = true;
		ret = setup_gpi_dma(gi2c);
		if (ret) {
			geni_se_resources_off(&gi2c->se);
			clk_disable_unprepare(gi2c->core_clk);
			return dev_err_probe(dev, ret, "Failed to setup GPI DMA mode\n");
		}

		dev_dbg(dev, "Using GPI DMA mode for I2C\n");
	} else {
		gi2c->gpi_mode = false;
		tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);

		/* I2C Master Hub Serial Elements doesn't have the HW_PARAM_0 register */
		if (!tx_depth && desc)
			tx_depth = desc->tx_fifo_depth;

		if (!tx_depth) {
			dev_err(dev, "Invalid TX FIFO depth\n");
			geni_se_resources_off(&gi2c->se);
			clk_disable_unprepare(gi2c->core_clk);
			return -EINVAL;
		}

		gi2c->tx_wm = tx_depth - 1;
		geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
		geni_se_config_packing(&gi2c->se, BITS_PER_BYTE,
				       PACKING_BYTES_PW, true, true, true);

		dev_dbg(dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
	}

	clk_disable_unprepare(gi2c->core_clk);
	ret = geni_se_resources_off(&gi2c->se);
	if (ret) {
		dev_err(dev, "Error turning off resources %d\n", ret);
		goto err_dma;
	}

	ret = geni_icc_disable(&gi2c->se);
	if (ret)
		goto err_dma;

	gi2c->suspended = 1;
	pm_runtime_set_suspended(gi2c->se.dev);
	pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
	pm_runtime_use_autosuspend(gi2c->se.dev);
	pm_runtime_enable(gi2c->se.dev);

	ret = i2c_add_adapter(&gi2c->adap);
	if (ret) {
		dev_err(dev, "Error adding i2c adapter %d\n", ret);
		pm_runtime_disable(gi2c->se.dev);
		goto err_dma;
	}

	dev_dbg(dev, "Geni-I2C adaptor successfully added\n");

	return 0;

err_dma:
	release_gpi_dma(gi2c);
	return ret;
}

static void geni_i2c_remove(struct platform_device *pdev)
{
	struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);

	i2c_del_adapter(&gi2c->adap);
	release_gpi_dma(gi2c);
	pm_runtime_disable(gi2c->se.dev);
}

static void geni_i2c_shutdown(struct platform_device *pdev)
{
	struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);

	/* Make client i2c transfers start failing */
	i2c_mark_adapter_suspended(&gi2c->adap);
}

static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
{
	int ret;
	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);

	disable_irq(gi2c->irq);
	ret = geni_se_resources_off(&gi2c->se);
	if (ret) {
		enable_irq(gi2c->irq);
		return ret;

	} else {
		gi2c->suspended = 1;
	}

	clk_disable_unprepare(gi2c->core_clk);

	return geni_icc_disable(&gi2c->se);
}

static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
{
	int ret;
	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);

	ret = geni_icc_enable(&gi2c->se);
	if (ret)
		return ret;

	ret = clk_prepare_enable(gi2c->core_clk);
	if (ret)
		return ret;

	ret = geni_se_resources_on(&gi2c->se);
	if (ret) {
		clk_disable_unprepare(gi2c->core_clk);
		geni_icc_disable(&gi2c->se);
		return ret;
	}

	enable_irq(gi2c->irq);
	gi2c->suspended = 0;
	return 0;
}

static int __maybe_unused geni_i2c_suspend_noirq(struct device *dev)
{
	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);

	i2c_mark_adapter_suspended(&gi2c->adap);

	if (!gi2c->suspended) {
		geni_i2c_runtime_suspend(dev);
		pm_runtime_disable(dev);
		pm_runtime_set_suspended(dev);
		pm_runtime_enable(dev);
	}
	return 0;
}

static int __maybe_unused geni_i2c_resume_noirq(struct device *dev)
{
	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);

	i2c_mark_adapter_resumed(&gi2c->adap);
	return 0;
}

static const struct dev_pm_ops geni_i2c_pm_ops = {
	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(geni_i2c_suspend_noirq, geni_i2c_resume_noirq)
	SET_RUNTIME_PM_OPS(geni_i2c_runtime_suspend, geni_i2c_runtime_resume,
									NULL)
};

static const struct geni_i2c_desc i2c_master_hub = {
	.has_core_clk = true,
	.icc_ddr = NULL,
	.no_dma_support = true,
	.tx_fifo_depth = 16,
};

static const struct of_device_id geni_i2c_dt_match[] = {
	{ .compatible = "qcom,geni-i2c" },
	{ .compatible = "qcom,geni-i2c-master-hub", .data = &i2c_master_hub },
	{}
};
MODULE_DEVICE_TABLE(of, geni_i2c_dt_match);

static struct platform_driver geni_i2c_driver = {
	.probe  = geni_i2c_probe,
	.remove_new = geni_i2c_remove,
	.shutdown = geni_i2c_shutdown,
	.driver = {
		.name = "geni_i2c",
		.pm = &geni_i2c_pm_ops,
		.of_match_table = geni_i2c_dt_match,
		.acpi_match_table = ACPI_PTR(geni_i2c_acpi_match),
	},
};

module_platform_driver(geni_i2c_driver);

MODULE_DESCRIPTION("I2C Controller Driver for GENI based QUP cores");
MODULE_LICENSE("GPL v2");