drivers/spi/spi-qcom-qspi.c - linux - Git at Google

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

 #include <linux/clk.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/pm_runtime.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/spi-mem.h>


 #define QSPI_NUM_CS		2
 #define QSPI_BYTES_PER_WORD	4

 #define MSTR_CONFIG		0x0000
 #define FULL_CYCLE_MODE		BIT(3)
 #define FB_CLK_EN		BIT(4)
 #define PIN_HOLDN		BIT(6)
 #define PIN_WPN			BIT(7)
 #define DMA_ENABLE		BIT(8)
 #define BIG_ENDIAN_MODE		BIT(9)
 #define SPI_MODE_MSK		0xc00
 #define SPI_MODE_SHFT		10
 #define CHIP_SELECT_NUM		BIT(12)
 #define SBL_EN			BIT(13)
 #define LPA_BASE_MSK		0x3c000
 #define LPA_BASE_SHFT		14
 #define TX_DATA_DELAY_MSK	0xc0000
 #define TX_DATA_DELAY_SHFT	18
 #define TX_CLK_DELAY_MSK	0x300000
 #define TX_CLK_DELAY_SHFT	20
 #define TX_CS_N_DELAY_MSK	0xc00000
 #define TX_CS_N_DELAY_SHFT	22
 #define TX_DATA_OE_DELAY_MSK	0x3000000
 #define TX_DATA_OE_DELAY_SHFT	24

 #define AHB_MASTER_CFG				0x0004
 #define HMEM_TYPE_START_MID_TRANS_MSK		0x7
 #define HMEM_TYPE_START_MID_TRANS_SHFT		0
 #define HMEM_TYPE_LAST_TRANS_MSK		0x38
 #define HMEM_TYPE_LAST_TRANS_SHFT		3
 #define USE_HMEMTYPE_LAST_ON_DESC_OR_CHAIN_MSK	0xc0
 #define USE_HMEMTYPE_LAST_ON_DESC_OR_CHAIN_SHFT	6
 #define HMEMTYPE_READ_TRANS_MSK			0x700
 #define HMEMTYPE_READ_TRANS_SHFT		8
 #define HSHARED					BIT(11)
 #define HINNERSHARED				BIT(12)

 #define MSTR_INT_EN		0x000C
 #define MSTR_INT_STATUS		0x0010
 #define RESP_FIFO_UNDERRUN	BIT(0)
 #define RESP_FIFO_NOT_EMPTY	BIT(1)
 #define RESP_FIFO_RDY		BIT(2)
 #define HRESP_FROM_NOC_ERR	BIT(3)
 #define WR_FIFO_EMPTY		BIT(9)
 #define WR_FIFO_FULL		BIT(10)
 #define WR_FIFO_OVERRUN		BIT(11)
 #define TRANSACTION_DONE	BIT(16)
 #define QSPI_ERR_IRQS		(RESP_FIFO_UNDERRUN | HRESP_FROM_NOC_ERR | \
 				 WR_FIFO_OVERRUN)
 #define QSPI_ALL_IRQS		(QSPI_ERR_IRQS | RESP_FIFO_RDY | \
 				 WR_FIFO_EMPTY | WR_FIFO_FULL | \
 				 TRANSACTION_DONE)

 #define PIO_XFER_CTRL		0x0014
 #define REQUEST_COUNT_MSK	0xffff

 #define PIO_XFER_CFG		0x0018
 #define TRANSFER_DIRECTION	BIT(0)
 #define MULTI_IO_MODE_MSK	0xe
 #define MULTI_IO_MODE_SHFT	1
 #define TRANSFER_FRAGMENT	BIT(8)
 #define SDR_1BIT		1
 #define SDR_2BIT		2
 #define SDR_4BIT		3
 #define DDR_1BIT		5
 #define DDR_2BIT		6
 #define DDR_4BIT		7
 #define DMA_DESC_SINGLE_SPI	1
 #define DMA_DESC_DUAL_SPI	2
 #define DMA_DESC_QUAD_SPI	3

 #define PIO_XFER_STATUS		0x001c
 #define WR_FIFO_BYTES_MSK	0xffff0000
 #define WR_FIFO_BYTES_SHFT	16

 #define PIO_DATAOUT_1B		0x0020
 #define PIO_DATAOUT_4B		0x0024

 #define RD_FIFO_CFG		0x0028
 #define CONTINUOUS_MODE		BIT(0)

 #define RD_FIFO_STATUS	0x002c
 #define FIFO_EMPTY	BIT(11)
 #define WR_CNTS_MSK	0x7f0
 #define WR_CNTS_SHFT	4
 #define RDY_64BYTE	BIT(3)
 #define RDY_32BYTE	BIT(2)
 #define RDY_16BYTE	BIT(1)
 #define FIFO_RDY	BIT(0)

 #define RD_FIFO_RESET		0x0030
 #define RESET_FIFO		BIT(0)

 #define CUR_MEM_ADDR		0x0048
 #define HW_VERSION		0x004c
 #define RD_FIFO			0x0050
 #define SAMPLING_CLK_CFG	0x0090
 #define SAMPLING_CLK_STATUS	0x0094


 enum qspi_dir {
 	QSPI_READ,
 	QSPI_WRITE,
 };

 struct qspi_xfer {
 	union {
 		const void *tx_buf;
 		void *rx_buf;
 	};
 	unsigned int rem_bytes;
 	unsigned int buswidth;
 	enum qspi_dir dir;
 	bool is_last;
 };

 enum qspi_clocks {
 	QSPI_CLK_CORE,
 	QSPI_CLK_IFACE,
 	QSPI_NUM_CLKS
 };

 struct qcom_qspi {
 	void __iomem *base;
 	struct device *dev;
 	struct clk_bulk_data clks[QSPI_NUM_CLKS];
 	struct qspi_xfer xfer;
 	/* Lock to protect xfer and IRQ accessed registers */
 	spinlock_t lock;
 };

 static u32 qspi_buswidth_to_iomode(struct qcom_qspi *ctrl,
 				   unsigned int buswidth)
 {
 	switch (buswidth) {
 	case 1:
 		return SDR_1BIT << MULTI_IO_MODE_SHFT;
 	case 2:
 		return SDR_2BIT << MULTI_IO_MODE_SHFT;
 	case 4:
 		return SDR_4BIT << MULTI_IO_MODE_SHFT;
 	default:
 		dev_warn_once(ctrl->dev,
 				"Unexpected bus width: %u\n", buswidth);
 		return SDR_1BIT << MULTI_IO_MODE_SHFT;
 	}
 }

 static void qcom_qspi_pio_xfer_cfg(struct qcom_qspi *ctrl)
 {
 	u32 pio_xfer_cfg;
 	const struct qspi_xfer *xfer;

 	xfer = &ctrl->xfer;
 	pio_xfer_cfg = readl(ctrl->base + PIO_XFER_CFG);
 	pio_xfer_cfg &= ~TRANSFER_DIRECTION;
 	pio_xfer_cfg |= xfer->dir;
 	if (xfer->is_last)
 		pio_xfer_cfg &= ~TRANSFER_FRAGMENT;
 	else
 		pio_xfer_cfg |= TRANSFER_FRAGMENT;
 	pio_xfer_cfg &= ~MULTI_IO_MODE_MSK;
 	pio_xfer_cfg |= qspi_buswidth_to_iomode(ctrl, xfer->buswidth);

 	writel(pio_xfer_cfg, ctrl->base + PIO_XFER_CFG);
 }

 static void qcom_qspi_pio_xfer_ctrl(struct qcom_qspi *ctrl)
 {
 	u32 pio_xfer_ctrl;

 	pio_xfer_ctrl = readl(ctrl->base + PIO_XFER_CTRL);
 	pio_xfer_ctrl &= ~REQUEST_COUNT_MSK;
 	pio_xfer_ctrl |= ctrl->xfer.rem_bytes;
 	writel(pio_xfer_ctrl, ctrl->base + PIO_XFER_CTRL);
 }

 static void qcom_qspi_pio_xfer(struct qcom_qspi *ctrl)
 {
 	u32 ints;

 	qcom_qspi_pio_xfer_cfg(ctrl);

 	/* Ack any previous interrupts that might be hanging around */
 	writel(QSPI_ALL_IRQS, ctrl->base + MSTR_INT_STATUS);

 	/* Setup new interrupts */
 	if (ctrl->xfer.dir == QSPI_WRITE)
 		ints = QSPI_ERR_IRQS | WR_FIFO_EMPTY;
 	else
 		ints = QSPI_ERR_IRQS | RESP_FIFO_RDY;
 	writel(ints, ctrl->base + MSTR_INT_EN);

 	/* Kick off the transfer */
 	qcom_qspi_pio_xfer_ctrl(ctrl);
 }

 static void qcom_qspi_handle_err(struct spi_master *master,
 				 struct spi_message *msg)
 {
 	struct qcom_qspi *ctrl = spi_master_get_devdata(master);
 	unsigned long flags;

 	spin_lock_irqsave(&ctrl->lock, flags);
 	writel(0, ctrl->base + MSTR_INT_EN);
 	ctrl->xfer.rem_bytes = 0;
 	spin_unlock_irqrestore(&ctrl->lock, flags);
 }

 static int qcom_qspi_transfer_one(struct spi_master *master,
 				  struct spi_device *slv,
 				  struct spi_transfer *xfer)
 {
 	struct qcom_qspi *ctrl = spi_master_get_devdata(master);
 	int ret;
 	unsigned long speed_hz;
 	unsigned long flags;

 	speed_hz = slv->max_speed_hz;
 	if (xfer->speed_hz)
 		speed_hz = xfer->speed_hz;

 	/* In regular operation (SBL_EN=1) core must be 4x transfer clock */
 	ret = clk_set_rate(ctrl->clks[QSPI_CLK_CORE].clk, speed_hz * 4);
 	if (ret) {
 		dev_err(ctrl->dev, "Failed to set core clk %d\n", ret);
 		return ret;
 	}

 	spin_lock_irqsave(&ctrl->lock, flags);

 	/* We are half duplex, so either rx or tx will be set */
 	if (xfer->rx_buf) {
 		ctrl->xfer.dir = QSPI_READ;
 		ctrl->xfer.buswidth = xfer->rx_nbits;
 		ctrl->xfer.rx_buf = xfer->rx_buf;
 	} else {
 		ctrl->xfer.dir = QSPI_WRITE;
 		ctrl->xfer.buswidth = xfer->tx_nbits;
 		ctrl->xfer.tx_buf = xfer->tx_buf;
 	}
 	ctrl->xfer.is_last = list_is_last(&xfer->transfer_list,
 					  &master->cur_msg->transfers);
 	ctrl->xfer.rem_bytes = xfer->len;
 	qcom_qspi_pio_xfer(ctrl);

 	spin_unlock_irqrestore(&ctrl->lock, flags);

 	/* We'll call spi_finalize_current_transfer() when done */
 	return 1;
 }

 static int qcom_qspi_prepare_message(struct spi_master *master,
 				     struct spi_message *message)
 {
 	u32 mstr_cfg;
 	struct qcom_qspi *ctrl;
 	int tx_data_oe_delay = 1;
 	int tx_data_delay = 1;
 	unsigned long flags;

 	ctrl = spi_master_get_devdata(master);
 	spin_lock_irqsave(&ctrl->lock, flags);

 	mstr_cfg = readl(ctrl->base + MSTR_CONFIG);
 	mstr_cfg &= ~CHIP_SELECT_NUM;
 	if (message->spi->chip_select)
 		mstr_cfg |= CHIP_SELECT_NUM;

 	mstr_cfg |= FB_CLK_EN | PIN_WPN | PIN_HOLDN | SBL_EN | FULL_CYCLE_MODE;
 	mstr_cfg &= ~(SPI_MODE_MSK | TX_DATA_OE_DELAY_MSK | TX_DATA_DELAY_MSK);
 	mstr_cfg |= message->spi->mode << SPI_MODE_SHFT;
 	mstr_cfg |= tx_data_oe_delay << TX_DATA_OE_DELAY_SHFT;
 	mstr_cfg |= tx_data_delay << TX_DATA_DELAY_SHFT;
 	mstr_cfg &= ~DMA_ENABLE;

 	writel(mstr_cfg, ctrl->base + MSTR_CONFIG);
 	spin_unlock_irqrestore(&ctrl->lock, flags);

 	return 0;
 }

 static irqreturn_t pio_read(struct qcom_qspi *ctrl)
 {
 	u32 rd_fifo_status;
 	u32 rd_fifo;
 	unsigned int wr_cnts;
 	unsigned int bytes_to_read;
 	unsigned int words_to_read;
 	u32 *word_buf;
 	u8 *byte_buf;
 	int i;

 	rd_fifo_status = readl(ctrl->base + RD_FIFO_STATUS);

 	if (!(rd_fifo_status & FIFO_RDY)) {
 		dev_dbg(ctrl->dev, "Spurious IRQ %#x\n", rd_fifo_status);
 		return IRQ_NONE;
 	}

 	wr_cnts = (rd_fifo_status & WR_CNTS_MSK) >> WR_CNTS_SHFT;
 	wr_cnts = min(wr_cnts, ctrl->xfer.rem_bytes);

 	words_to_read = wr_cnts / QSPI_BYTES_PER_WORD;
 	bytes_to_read = wr_cnts % QSPI_BYTES_PER_WORD;

 	if (words_to_read) {
 		word_buf = ctrl->xfer.rx_buf;
 		ctrl->xfer.rem_bytes -= words_to_read * QSPI_BYTES_PER_WORD;
 		ioread32_rep(ctrl->base + RD_FIFO, word_buf, words_to_read);
 		ctrl->xfer.rx_buf = word_buf + words_to_read;
 	}

 	if (bytes_to_read) {
 		byte_buf = ctrl->xfer.rx_buf;
 		rd_fifo = readl(ctrl->base + RD_FIFO);
 		ctrl->xfer.rem_bytes -= bytes_to_read;
 		for (i = 0; i < bytes_to_read; i++)
 			*byte_buf++ = rd_fifo >> (i * BITS_PER_BYTE);
 		ctrl->xfer.rx_buf = byte_buf;
 	}

 	return IRQ_HANDLED;
 }

 static irqreturn_t pio_write(struct qcom_qspi *ctrl)
 {
 	const void *xfer_buf = ctrl->xfer.tx_buf;
 	const int *word_buf;
 	const char *byte_buf;
 	unsigned int wr_fifo_bytes;
 	unsigned int wr_fifo_words;
 	unsigned int wr_size;
 	unsigned int rem_words;

 	wr_fifo_bytes = readl(ctrl->base + PIO_XFER_STATUS);
 	wr_fifo_bytes >>= WR_FIFO_BYTES_SHFT;

 	if (ctrl->xfer.rem_bytes < QSPI_BYTES_PER_WORD) {
 		/* Process the last 1-3 bytes */
 		wr_size = min(wr_fifo_bytes, ctrl->xfer.rem_bytes);
 		ctrl->xfer.rem_bytes -= wr_size;

 		byte_buf = xfer_buf;
 		while (wr_size--)
 			writel(*byte_buf++,
 			       ctrl->base + PIO_DATAOUT_1B);
 		ctrl->xfer.tx_buf = byte_buf;
 	} else {
 		/*
 		 * Process all the whole words; to keep things simple we'll
 		 * just wait for the next interrupt to handle the last 1-3
 		 * bytes if we don't have an even number of words.
 		 */
 		rem_words = ctrl->xfer.rem_bytes / QSPI_BYTES_PER_WORD;
 		wr_fifo_words = wr_fifo_bytes / QSPI_BYTES_PER_WORD;

 		wr_size = min(rem_words, wr_fifo_words);
 		ctrl->xfer.rem_bytes -= wr_size * QSPI_BYTES_PER_WORD;

 		word_buf = xfer_buf;
 		iowrite32_rep(ctrl->base + PIO_DATAOUT_4B, word_buf, wr_size);
 		ctrl->xfer.tx_buf = word_buf + wr_size;

 	}

 	return IRQ_HANDLED;
 }

 static irqreturn_t qcom_qspi_irq(int irq, void *dev_id)
 {
 	u32 int_status;
 	struct qcom_qspi *ctrl = dev_id;
 	irqreturn_t ret = IRQ_NONE;
 	unsigned long flags;

 	spin_lock_irqsave(&ctrl->lock, flags);

 	int_status = readl(ctrl->base + MSTR_INT_STATUS);
 	writel(int_status, ctrl->base + MSTR_INT_STATUS);

 	if (ctrl->xfer.dir == QSPI_WRITE) {
 		if (int_status & WR_FIFO_EMPTY)
 			ret = pio_write(ctrl);
 	} else {
 		if (int_status & RESP_FIFO_RDY)
 			ret = pio_read(ctrl);
 	}

 	if (int_status & QSPI_ERR_IRQS) {
 		if (int_status & RESP_FIFO_UNDERRUN)
 			dev_err(ctrl->dev, "IRQ error: FIFO underrun\n");
 		if (int_status & WR_FIFO_OVERRUN)
 			dev_err(ctrl->dev, "IRQ error: FIFO overrun\n");
 		if (int_status & HRESP_FROM_NOC_ERR)
 			dev_err(ctrl->dev, "IRQ error: NOC response error\n");
 		ret = IRQ_HANDLED;
 	}

 	if (!ctrl->xfer.rem_bytes) {
 		writel(0, ctrl->base + MSTR_INT_EN);
 		spi_finalize_current_transfer(dev_get_drvdata(ctrl->dev));
 	}

 	spin_unlock_irqrestore(&ctrl->lock, flags);
 	return ret;
 }

 static int qcom_qspi_probe(struct platform_device *pdev)
 {
 	int ret;
 	struct device *dev;
 	struct resource *res;
 	struct spi_master *master;
 	struct qcom_qspi *ctrl;

 	dev = &pdev->dev;

 	master = spi_alloc_master(dev, sizeof(*ctrl));
 	if (!master)
 		return -ENOMEM;

 	platform_set_drvdata(pdev, master);

 	ctrl = spi_master_get_devdata(master);

 	spin_lock_init(&ctrl->lock);
 	ctrl->dev = dev;
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	ctrl->base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(ctrl->base)) {
 		ret = PTR_ERR(ctrl->base);
 		goto exit_probe_master_put;
 	}

 	ctrl->clks[QSPI_CLK_CORE].id = "core";
 	ctrl->clks[QSPI_CLK_IFACE].id = "iface";
 	ret = devm_clk_bulk_get(dev, QSPI_NUM_CLKS, ctrl->clks);
 	if (ret)
 		goto exit_probe_master_put;

 	ret = platform_get_irq(pdev, 0);
 	if (ret < 0) {
 		dev_err(dev, "Failed to get irq %d\n", ret);
 		goto exit_probe_master_put;
 	}
 	ret = devm_request_irq(dev, ret, qcom_qspi_irq,
 			IRQF_TRIGGER_HIGH, dev_name(dev), ctrl);
 	if (ret) {
 		dev_err(dev, "Failed to request irq %d\n", ret);
 		goto exit_probe_master_put;
 	}

 	master->max_speed_hz = 300000000;
 	master->num_chipselect = QSPI_NUM_CS;
 	master->bus_num = -1;
 	master->dev.of_node = pdev->dev.of_node;
 	master->mode_bits = SPI_MODE_0 |
 			    SPI_TX_DUAL | SPI_RX_DUAL |
 			    SPI_TX_QUAD | SPI_RX_QUAD;
 	master->flags = SPI_MASTER_HALF_DUPLEX;
 	master->prepare_message = qcom_qspi_prepare_message;
 	master->transfer_one = qcom_qspi_transfer_one;
 	master->handle_err = qcom_qspi_handle_err;
 	master->auto_runtime_pm = true;

 	pm_runtime_enable(dev);

 	ret = spi_register_master(master);
 	if (!ret)
 		return 0;

 	pm_runtime_disable(dev);

 exit_probe_master_put:
 	spi_master_put(master);

 	return ret;
 }

 static int qcom_qspi_remove(struct platform_device *pdev)
 {
 	struct spi_master *master = platform_get_drvdata(pdev);

 	/* Unregister _before_ disabling pm_runtime() so we stop transfers */
 	spi_unregister_master(master);

 	pm_runtime_disable(&pdev->dev);

 	return 0;
 }

 static int __maybe_unused qcom_qspi_runtime_suspend(struct device *dev)
 {
 	struct spi_master *master = dev_get_drvdata(dev);
 	struct qcom_qspi *ctrl = spi_master_get_devdata(master);

 	clk_bulk_disable_unprepare(QSPI_NUM_CLKS, ctrl->clks);

 	return 0;
 }

 static int __maybe_unused qcom_qspi_runtime_resume(struct device *dev)
 {
 	struct spi_master *master = dev_get_drvdata(dev);
 	struct qcom_qspi *ctrl = spi_master_get_devdata(master);

 	return clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks);
 }

 static int __maybe_unused qcom_qspi_suspend(struct device *dev)
 {
 	struct spi_master *master = dev_get_drvdata(dev);
 	int ret;

 	ret = spi_master_suspend(master);
 	if (ret)
 		return ret;

 	ret = pm_runtime_force_suspend(dev);
 	if (ret)
 		spi_master_resume(master);

 	return ret;
 }

 static int __maybe_unused qcom_qspi_resume(struct device *dev)
 {
 	struct spi_master *master = dev_get_drvdata(dev);
 	int ret;

 	ret = pm_runtime_force_resume(dev);
 	if (ret)
 		return ret;

 	ret = spi_master_resume(master);
 	if (ret)
 		pm_runtime_force_suspend(dev);

 	return ret;
 }

 static const struct dev_pm_ops qcom_qspi_dev_pm_ops = {
 	SET_RUNTIME_PM_OPS(qcom_qspi_runtime_suspend,
 			   qcom_qspi_runtime_resume, NULL)
 	SET_SYSTEM_SLEEP_PM_OPS(qcom_qspi_suspend, qcom_qspi_resume)
 };

 static const struct of_device_id qcom_qspi_dt_match[] = {
 	{ .compatible = "qcom,qspi-v1", },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, qcom_qspi_dt_match);

 static struct platform_driver qcom_qspi_driver = {
 	.driver = {
 		.name		= "qcom_qspi",
 		.pm		= &qcom_qspi_dev_pm_ops,
 		.of_match_table = qcom_qspi_dt_match,
 	},
 	.probe = qcom_qspi_probe,
 	.remove = qcom_qspi_remove,
 };
 module_platform_driver(qcom_qspi_driver);

 MODULE_DESCRIPTION("SPI driver for QSPI cores");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.

	#include <linux/clk.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_platform.h>
	#include <linux/pm_runtime.h>
	#include <linux/spi/spi.h>
	#include <linux/spi/spi-mem.h>


	#define QSPI_NUM_CS 2
	#define QSPI_BYTES_PER_WORD 4

	#define MSTR_CONFIG 0x0000
	#define FULL_CYCLE_MODE BIT(3)
	#define FB_CLK_EN BIT(4)
	#define PIN_HOLDN BIT(6)
	#define PIN_WPN BIT(7)
	#define DMA_ENABLE BIT(8)
	#define BIG_ENDIAN_MODE BIT(9)
	#define SPI_MODE_MSK 0xc00
	#define SPI_MODE_SHFT 10
	#define CHIP_SELECT_NUM BIT(12)
	#define SBL_EN BIT(13)
	#define LPA_BASE_MSK 0x3c000
	#define LPA_BASE_SHFT 14
	#define TX_DATA_DELAY_MSK 0xc0000
	#define TX_DATA_DELAY_SHFT 18
	#define TX_CLK_DELAY_MSK 0x300000
	#define TX_CLK_DELAY_SHFT 20
	#define TX_CS_N_DELAY_MSK 0xc00000
	#define TX_CS_N_DELAY_SHFT 22
	#define TX_DATA_OE_DELAY_MSK 0x3000000
	#define TX_DATA_OE_DELAY_SHFT 24

	#define AHB_MASTER_CFG 0x0004
	#define HMEM_TYPE_START_MID_TRANS_MSK 0x7
	#define HMEM_TYPE_START_MID_TRANS_SHFT 0
	#define HMEM_TYPE_LAST_TRANS_MSK 0x38
	#define HMEM_TYPE_LAST_TRANS_SHFT 3
	#define USE_HMEMTYPE_LAST_ON_DESC_OR_CHAIN_MSK 0xc0
	#define USE_HMEMTYPE_LAST_ON_DESC_OR_CHAIN_SHFT 6
	#define HMEMTYPE_READ_TRANS_MSK 0x700
	#define HMEMTYPE_READ_TRANS_SHFT 8
	#define HSHARED BIT(11)
	#define HINNERSHARED BIT(12)

	#define MSTR_INT_EN 0x000C
	#define MSTR_INT_STATUS 0x0010
	#define RESP_FIFO_UNDERRUN BIT(0)
	#define RESP_FIFO_NOT_EMPTY BIT(1)
	#define RESP_FIFO_RDY BIT(2)
	#define HRESP_FROM_NOC_ERR BIT(3)
	#define WR_FIFO_EMPTY BIT(9)
	#define WR_FIFO_FULL BIT(10)
	#define WR_FIFO_OVERRUN BIT(11)
	#define TRANSACTION_DONE BIT(16)
	#define QSPI_ERR_IRQS (RESP_FIFO_UNDERRUN \| HRESP_FROM_NOC_ERR \| \
	WR_FIFO_OVERRUN)
	#define QSPI_ALL_IRQS (QSPI_ERR_IRQS \| RESP_FIFO_RDY \| \
	WR_FIFO_EMPTY \| WR_FIFO_FULL \| \
	TRANSACTION_DONE)

	#define PIO_XFER_CTRL 0x0014
	#define REQUEST_COUNT_MSK 0xffff

	#define PIO_XFER_CFG 0x0018
	#define TRANSFER_DIRECTION BIT(0)
	#define MULTI_IO_MODE_MSK 0xe
	#define MULTI_IO_MODE_SHFT 1
	#define TRANSFER_FRAGMENT BIT(8)
	#define SDR_1BIT 1
	#define SDR_2BIT 2
	#define SDR_4BIT 3
	#define DDR_1BIT 5
	#define DDR_2BIT 6
	#define DDR_4BIT 7
	#define DMA_DESC_SINGLE_SPI 1
	#define DMA_DESC_DUAL_SPI 2
	#define DMA_DESC_QUAD_SPI 3

	#define PIO_XFER_STATUS 0x001c
	#define WR_FIFO_BYTES_MSK 0xffff0000
	#define WR_FIFO_BYTES_SHFT 16

	#define PIO_DATAOUT_1B 0x0020
	#define PIO_DATAOUT_4B 0x0024

	#define RD_FIFO_CFG 0x0028
	#define CONTINUOUS_MODE BIT(0)

	#define RD_FIFO_STATUS 0x002c
	#define FIFO_EMPTY BIT(11)
	#define WR_CNTS_MSK 0x7f0
	#define WR_CNTS_SHFT 4
	#define RDY_64BYTE BIT(3)
	#define RDY_32BYTE BIT(2)
	#define RDY_16BYTE BIT(1)
	#define FIFO_RDY BIT(0)

	#define RD_FIFO_RESET 0x0030
	#define RESET_FIFO BIT(0)

	#define CUR_MEM_ADDR 0x0048
	#define HW_VERSION 0x004c
	#define RD_FIFO 0x0050
	#define SAMPLING_CLK_CFG 0x0090
	#define SAMPLING_CLK_STATUS 0x0094


	enum qspi_dir {
	QSPI_READ,
	QSPI_WRITE,
	};

	struct qspi_xfer {
	union {
	const void *tx_buf;
	void *rx_buf;
	};
	unsigned int rem_bytes;
	unsigned int buswidth;
	enum qspi_dir dir;
	bool is_last;
	};

	enum qspi_clocks {
	QSPI_CLK_CORE,
	QSPI_CLK_IFACE,
	QSPI_NUM_CLKS
	};

	struct qcom_qspi {
	void __iomem *base;
	struct device *dev;
	struct clk_bulk_data clks[QSPI_NUM_CLKS];
	struct qspi_xfer xfer;
	/* Lock to protect xfer and IRQ accessed registers */
	spinlock_t lock;
	};

	static u32 qspi_buswidth_to_iomode(struct qcom_qspi *ctrl,
	unsigned int buswidth)
	{
	switch (buswidth) {
	case 1:
	return SDR_1BIT << MULTI_IO_MODE_SHFT;
	case 2:
	return SDR_2BIT << MULTI_IO_MODE_SHFT;
	case 4:
	return SDR_4BIT << MULTI_IO_MODE_SHFT;
	default:
	dev_warn_once(ctrl->dev,
	"Unexpected bus width: %u\n", buswidth);
	return SDR_1BIT << MULTI_IO_MODE_SHFT;
	}
	}

	static void qcom_qspi_pio_xfer_cfg(struct qcom_qspi *ctrl)
	{
	u32 pio_xfer_cfg;
	const struct qspi_xfer *xfer;

	xfer = &ctrl->xfer;
	pio_xfer_cfg = readl(ctrl->base + PIO_XFER_CFG);
	pio_xfer_cfg &= ~TRANSFER_DIRECTION;
	pio_xfer_cfg \|= xfer->dir;
	if (xfer->is_last)
	pio_xfer_cfg &= ~TRANSFER_FRAGMENT;
	else
	pio_xfer_cfg \|= TRANSFER_FRAGMENT;
	pio_xfer_cfg &= ~MULTI_IO_MODE_MSK;
	pio_xfer_cfg \|= qspi_buswidth_to_iomode(ctrl, xfer->buswidth);

	writel(pio_xfer_cfg, ctrl->base + PIO_XFER_CFG);
	}

	static void qcom_qspi_pio_xfer_ctrl(struct qcom_qspi *ctrl)
	{
	u32 pio_xfer_ctrl;

	pio_xfer_ctrl = readl(ctrl->base + PIO_XFER_CTRL);
	pio_xfer_ctrl &= ~REQUEST_COUNT_MSK;
	pio_xfer_ctrl \|= ctrl->xfer.rem_bytes;
	writel(pio_xfer_ctrl, ctrl->base + PIO_XFER_CTRL);
	}

	static void qcom_qspi_pio_xfer(struct qcom_qspi *ctrl)
	{
	u32 ints;

	qcom_qspi_pio_xfer_cfg(ctrl);

	/* Ack any previous interrupts that might be hanging around */
	writel(QSPI_ALL_IRQS, ctrl->base + MSTR_INT_STATUS);

	/* Setup new interrupts */
	if (ctrl->xfer.dir == QSPI_WRITE)
	ints = QSPI_ERR_IRQS \| WR_FIFO_EMPTY;
	else
	ints = QSPI_ERR_IRQS \| RESP_FIFO_RDY;
	writel(ints, ctrl->base + MSTR_INT_EN);

	/* Kick off the transfer */
	qcom_qspi_pio_xfer_ctrl(ctrl);
	}

	static void qcom_qspi_handle_err(struct spi_master *master,
	struct spi_message *msg)
	{
	struct qcom_qspi *ctrl = spi_master_get_devdata(master);
	unsigned long flags;

	spin_lock_irqsave(&ctrl->lock, flags);
	writel(0, ctrl->base + MSTR_INT_EN);
	ctrl->xfer.rem_bytes = 0;
	spin_unlock_irqrestore(&ctrl->lock, flags);
	}

	static int qcom_qspi_transfer_one(struct spi_master *master,
	struct spi_device *slv,
	struct spi_transfer *xfer)
	{
	struct qcom_qspi *ctrl = spi_master_get_devdata(master);
	int ret;
	unsigned long speed_hz;
	unsigned long flags;

	speed_hz = slv->max_speed_hz;
	if (xfer->speed_hz)
	speed_hz = xfer->speed_hz;

	/* In regular operation (SBL_EN=1) core must be 4x transfer clock */
	ret = clk_set_rate(ctrl->clks[QSPI_CLK_CORE].clk, speed_hz * 4);
	if (ret) {
	dev_err(ctrl->dev, "Failed to set core clk %d\n", ret);
	return ret;
	}

	spin_lock_irqsave(&ctrl->lock, flags);

	/* We are half duplex, so either rx or tx will be set */
	if (xfer->rx_buf) {
	ctrl->xfer.dir = QSPI_READ;
	ctrl->xfer.buswidth = xfer->rx_nbits;
	ctrl->xfer.rx_buf = xfer->rx_buf;
	} else {
	ctrl->xfer.dir = QSPI_WRITE;
	ctrl->xfer.buswidth = xfer->tx_nbits;
	ctrl->xfer.tx_buf = xfer->tx_buf;
	}
	ctrl->xfer.is_last = list_is_last(&xfer->transfer_list,
	&master->cur_msg->transfers);
	ctrl->xfer.rem_bytes = xfer->len;
	qcom_qspi_pio_xfer(ctrl);

	spin_unlock_irqrestore(&ctrl->lock, flags);

	/* We'll call spi_finalize_current_transfer() when done */
	return 1;
	}

	static int qcom_qspi_prepare_message(struct spi_master *master,
	struct spi_message *message)
	{
	u32 mstr_cfg;
	struct qcom_qspi *ctrl;
	int tx_data_oe_delay = 1;
	int tx_data_delay = 1;
	unsigned long flags;

	ctrl = spi_master_get_devdata(master);
	spin_lock_irqsave(&ctrl->lock, flags);

	mstr_cfg = readl(ctrl->base + MSTR_CONFIG);
	mstr_cfg &= ~CHIP_SELECT_NUM;
	if (message->spi->chip_select)
	mstr_cfg \|= CHIP_SELECT_NUM;

	mstr_cfg \|= FB_CLK_EN \| PIN_WPN \| PIN_HOLDN \| SBL_EN \| FULL_CYCLE_MODE;
	mstr_cfg &= ~(SPI_MODE_MSK \| TX_DATA_OE_DELAY_MSK \| TX_DATA_DELAY_MSK);
	mstr_cfg \|= message->spi->mode << SPI_MODE_SHFT;
	mstr_cfg \|= tx_data_oe_delay << TX_DATA_OE_DELAY_SHFT;
	mstr_cfg \|= tx_data_delay << TX_DATA_DELAY_SHFT;
	mstr_cfg &= ~DMA_ENABLE;

	writel(mstr_cfg, ctrl->base + MSTR_CONFIG);
	spin_unlock_irqrestore(&ctrl->lock, flags);

	return 0;
	}

	static irqreturn_t pio_read(struct qcom_qspi *ctrl)
	{
	u32 rd_fifo_status;
	u32 rd_fifo;
	unsigned int wr_cnts;
	unsigned int bytes_to_read;
	unsigned int words_to_read;
	u32 *word_buf;
	u8 *byte_buf;
	int i;

	rd_fifo_status = readl(ctrl->base + RD_FIFO_STATUS);

	if (!(rd_fifo_status & FIFO_RDY)) {
	dev_dbg(ctrl->dev, "Spurious IRQ %#x\n", rd_fifo_status);
	return IRQ_NONE;
	}

	wr_cnts = (rd_fifo_status & WR_CNTS_MSK) >> WR_CNTS_SHFT;
	wr_cnts = min(wr_cnts, ctrl->xfer.rem_bytes);

	words_to_read = wr_cnts / QSPI_BYTES_PER_WORD;
	bytes_to_read = wr_cnts % QSPI_BYTES_PER_WORD;

	if (words_to_read) {
	word_buf = ctrl->xfer.rx_buf;
	ctrl->xfer.rem_bytes -= words_to_read * QSPI_BYTES_PER_WORD;
	ioread32_rep(ctrl->base + RD_FIFO, word_buf, words_to_read);
	ctrl->xfer.rx_buf = word_buf + words_to_read;
	}

	if (bytes_to_read) {
	byte_buf = ctrl->xfer.rx_buf;
	rd_fifo = readl(ctrl->base + RD_FIFO);
	ctrl->xfer.rem_bytes -= bytes_to_read;
	for (i = 0; i < bytes_to_read; i++)
	byte_buf++ = rd_fifo >> (i BITS_PER_BYTE);
	ctrl->xfer.rx_buf = byte_buf;
	}

	return IRQ_HANDLED;
	}

	static irqreturn_t pio_write(struct qcom_qspi *ctrl)
	{
	const void *xfer_buf = ctrl->xfer.tx_buf;
	const int *word_buf;
	const char *byte_buf;
	unsigned int wr_fifo_bytes;
	unsigned int wr_fifo_words;
	unsigned int wr_size;
	unsigned int rem_words;

	wr_fifo_bytes = readl(ctrl->base + PIO_XFER_STATUS);
	wr_fifo_bytes >>= WR_FIFO_BYTES_SHFT;

	if (ctrl->xfer.rem_bytes < QSPI_BYTES_PER_WORD) {
	/* Process the last 1-3 bytes */
	wr_size = min(wr_fifo_bytes, ctrl->xfer.rem_bytes);
	ctrl->xfer.rem_bytes -= wr_size;

	byte_buf = xfer_buf;
	while (wr_size--)
	writel(*byte_buf++,
	ctrl->base + PIO_DATAOUT_1B);
	ctrl->xfer.tx_buf = byte_buf;
	} else {
	/*
	* Process all the whole words; to keep things simple we'll
	* just wait for the next interrupt to handle the last 1-3
	* bytes if we don't have an even number of words.
	*/
	rem_words = ctrl->xfer.rem_bytes / QSPI_BYTES_PER_WORD;
	wr_fifo_words = wr_fifo_bytes / QSPI_BYTES_PER_WORD;

	wr_size = min(rem_words, wr_fifo_words);
	ctrl->xfer.rem_bytes -= wr_size * QSPI_BYTES_PER_WORD;

	word_buf = xfer_buf;
	iowrite32_rep(ctrl->base + PIO_DATAOUT_4B, word_buf, wr_size);
	ctrl->xfer.tx_buf = word_buf + wr_size;

	}

	return IRQ_HANDLED;
	}

	static irqreturn_t qcom_qspi_irq(int irq, void *dev_id)
	{
	u32 int_status;
	struct qcom_qspi *ctrl = dev_id;
	irqreturn_t ret = IRQ_NONE;
	unsigned long flags;

	spin_lock_irqsave(&ctrl->lock, flags);

	int_status = readl(ctrl->base + MSTR_INT_STATUS);
	writel(int_status, ctrl->base + MSTR_INT_STATUS);

	if (ctrl->xfer.dir == QSPI_WRITE) {
	if (int_status & WR_FIFO_EMPTY)
	ret = pio_write(ctrl);
	} else {
	if (int_status & RESP_FIFO_RDY)
	ret = pio_read(ctrl);
	}

	if (int_status & QSPI_ERR_IRQS) {
	if (int_status & RESP_FIFO_UNDERRUN)
	dev_err(ctrl->dev, "IRQ error: FIFO underrun\n");
	if (int_status & WR_FIFO_OVERRUN)
	dev_err(ctrl->dev, "IRQ error: FIFO overrun\n");
	if (int_status & HRESP_FROM_NOC_ERR)
	dev_err(ctrl->dev, "IRQ error: NOC response error\n");
	ret = IRQ_HANDLED;
	}

	if (!ctrl->xfer.rem_bytes) {
	writel(0, ctrl->base + MSTR_INT_EN);
	spi_finalize_current_transfer(dev_get_drvdata(ctrl->dev));
	}

	spin_unlock_irqrestore(&ctrl->lock, flags);
	return ret;
	}

	static int qcom_qspi_probe(struct platform_device *pdev)
	{
	int ret;
	struct device *dev;
	struct resource *res;
	struct spi_master *master;
	struct qcom_qspi *ctrl;

	dev = &pdev->dev;

	master = spi_alloc_master(dev, sizeof(*ctrl));
	if (!master)
	return -ENOMEM;

	platform_set_drvdata(pdev, master);

	ctrl = spi_master_get_devdata(master);

	spin_lock_init(&ctrl->lock);
	ctrl->dev = dev;
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ctrl->base = devm_ioremap_resource(dev, res);
	if (IS_ERR(ctrl->base)) {
	ret = PTR_ERR(ctrl->base);
	goto exit_probe_master_put;
	}

	ctrl->clks[QSPI_CLK_CORE].id = "core";
	ctrl->clks[QSPI_CLK_IFACE].id = "iface";
	ret = devm_clk_bulk_get(dev, QSPI_NUM_CLKS, ctrl->clks);
	if (ret)
	goto exit_probe_master_put;

	ret = platform_get_irq(pdev, 0);
	if (ret < 0) {
	dev_err(dev, "Failed to get irq %d\n", ret);
	goto exit_probe_master_put;
	}
	ret = devm_request_irq(dev, ret, qcom_qspi_irq,
	IRQF_TRIGGER_HIGH, dev_name(dev), ctrl);
	if (ret) {
	dev_err(dev, "Failed to request irq %d\n", ret);
	goto exit_probe_master_put;
	}

	master->max_speed_hz = 300000000;
	master->num_chipselect = QSPI_NUM_CS;
	master->bus_num = -1;
	master->dev.of_node = pdev->dev.of_node;
	master->mode_bits = SPI_MODE_0 \|
	SPI_TX_DUAL \| SPI_RX_DUAL \|
	SPI_TX_QUAD \| SPI_RX_QUAD;
	master->flags = SPI_MASTER_HALF_DUPLEX;
	master->prepare_message = qcom_qspi_prepare_message;
	master->transfer_one = qcom_qspi_transfer_one;
	master->handle_err = qcom_qspi_handle_err;
	master->auto_runtime_pm = true;

	pm_runtime_enable(dev);

	ret = spi_register_master(master);
	if (!ret)
	return 0;

	pm_runtime_disable(dev);

	exit_probe_master_put:
	spi_master_put(master);

	return ret;
	}

	static int qcom_qspi_remove(struct platform_device *pdev)
	{
	struct spi_master *master = platform_get_drvdata(pdev);

	/* Unregister _before_ disabling pm_runtime() so we stop transfers */
	spi_unregister_master(master);

	pm_runtime_disable(&pdev->dev);

	return 0;
	}

	static int __maybe_unused qcom_qspi_runtime_suspend(struct device *dev)
	{
	struct spi_master *master = dev_get_drvdata(dev);
	struct qcom_qspi *ctrl = spi_master_get_devdata(master);

	clk_bulk_disable_unprepare(QSPI_NUM_CLKS, ctrl->clks);

	return 0;
	}

	static int __maybe_unused qcom_qspi_runtime_resume(struct device *dev)
	{
	struct spi_master *master = dev_get_drvdata(dev);
	struct qcom_qspi *ctrl = spi_master_get_devdata(master);

	return clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks);
	}

	static int __maybe_unused qcom_qspi_suspend(struct device *dev)
	{
	struct spi_master *master = dev_get_drvdata(dev);
	int ret;

	ret = spi_master_suspend(master);
	if (ret)
	return ret;

	ret = pm_runtime_force_suspend(dev);
	if (ret)
	spi_master_resume(master);

	return ret;
	}

	static int __maybe_unused qcom_qspi_resume(struct device *dev)
	{
	struct spi_master *master = dev_get_drvdata(dev);
	int ret;

	ret = pm_runtime_force_resume(dev);
	if (ret)
	return ret;

	ret = spi_master_resume(master);
	if (ret)
	pm_runtime_force_suspend(dev);

	return ret;
	}

	static const struct dev_pm_ops qcom_qspi_dev_pm_ops = {
	SET_RUNTIME_PM_OPS(qcom_qspi_runtime_suspend,
	qcom_qspi_runtime_resume, NULL)
	SET_SYSTEM_SLEEP_PM_OPS(qcom_qspi_suspend, qcom_qspi_resume)
	};

	static const struct of_device_id qcom_qspi_dt_match[] = {
	{ .compatible = "qcom,qspi-v1", },
	{ }
	};
	MODULE_DEVICE_TABLE(of, qcom_qspi_dt_match);

	static struct platform_driver qcom_qspi_driver = {
	.driver = {
	.name = "qcom_qspi",
	.pm = &qcom_qspi_dev_pm_ops,
	.of_match_table = qcom_qspi_dt_match,
	},
	.probe = qcom_qspi_probe,
	.remove = qcom_qspi_remove,
	};
	module_platform_driver(qcom_qspi_driver);

	MODULE_DESCRIPTION("SPI driver for QSPI cores");
	MODULE_LICENSE("GPL v2");