Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 916 insertions, 0 deletions

diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
new file mode 100644
index 0000000000..49b7751344
--- /dev/null
+++ b/drivers/spi/spi-qcom-qspi.c
@@ -0,0 +1,916 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
+
+#include <linux/clk.h>
+#include <linux/dmapool.h>
+#include <linux/dma-mapping.h>
+#include <linux/interconnect.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pm_runtime.h>
+#include <linux/pm_opp.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 DMA_CHAIN_DONE		BIT(31)
+#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 | DMA_CHAIN_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 NEXT_DMA_DESC_ADDR	0x0040
+#define CURRENT_DMA_DESC_ADDR	0x0044
+#define CURRENT_MEM_ADDR	0x0048
+
+#define CUR_MEM_ADDR		0x0048
+#define HW_VERSION		0x004c
+#define RD_FIFO			0x0050
+#define SAMPLING_CLK_CFG	0x0090
+#define SAMPLING_CLK_STATUS	0x0094
+
+#define QSPI_ALIGN_REQ	32
+
+enum qspi_dir {
+	QSPI_READ,
+	QSPI_WRITE,
+};
+
+struct qspi_cmd_desc {
+	u32 data_address;
+	u32 next_descriptor;
+	u32 direction:1;
+	u32 multi_io_mode:3;
+	u32 reserved1:4;
+	u32 fragment:1;
+	u32 reserved2:7;
+	u32 length:16;
+};
+
+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
+};
+
+/*
+ * Number of entries in sgt returned from spi framework that-
+ * will be supported. Can be modified as required.
+ * In practice, given max_dma_len is 64KB, the number of
+ * entries is not expected to exceed 1.
+ */
+#define QSPI_MAX_SG 5
+
+struct qcom_qspi {
+	void __iomem *base;
+	struct device *dev;
+	struct clk_bulk_data *clks;
+	struct qspi_xfer xfer;
+	struct dma_pool *dma_cmd_pool;
+	dma_addr_t dma_cmd_desc[QSPI_MAX_SG];
+	void *virt_cmd_desc[QSPI_MAX_SG];
+	unsigned int n_cmd_desc;
+	struct icc_path *icc_path_cpu_to_qspi;
+	unsigned long last_speed;
+	/* Lock to protect data accessed by IRQs */
+	spinlock_t lock;
+};
+
+static u32 qspi_buswidth_to_iomode(struct qcom_qspi *ctrl,
+				   unsigned int buswidth)
+{
+	switch (buswidth) {
+	case 1:
+		return SDR_1BIT;
+	case 2:
+		return SDR_2BIT;
+	case 4:
+		return SDR_4BIT;
+	default:
+		dev_warn_once(ctrl->dev,
+				"Unexpected bus width: %u\n", buswidth);
+		return SDR_1BIT;
+	}
+}
+
+static void qcom_qspi_pio_xfer_cfg(struct qcom_qspi *ctrl)
+{
+	u32 pio_xfer_cfg;
+	u32 iomode;
+	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;
+	iomode = qspi_buswidth_to_iomode(ctrl, xfer->buswidth);
+	pio_xfer_cfg |= iomode << MULTI_IO_MODE_SHFT;
+
+	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_controller *host,
+				 struct spi_message *msg)
+{
+	u32 int_status;
+	struct qcom_qspi *ctrl = spi_controller_get_devdata(host);
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&ctrl->lock, flags);
+	writel(0, ctrl->base + MSTR_INT_EN);
+	int_status = readl(ctrl->base + MSTR_INT_STATUS);
+	writel(int_status, ctrl->base + MSTR_INT_STATUS);
+	ctrl->xfer.rem_bytes = 0;
+
+	/* free cmd descriptors if they are around (DMA mode) */
+	for (i = 0; i < ctrl->n_cmd_desc; i++)
+		dma_pool_free(ctrl->dma_cmd_pool, ctrl->virt_cmd_desc[i],
+				  ctrl->dma_cmd_desc[i]);
+	ctrl->n_cmd_desc = 0;
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+}
+
+static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz)
+{
+	int ret;
+	unsigned int avg_bw_cpu;
+
+	if (speed_hz == ctrl->last_speed)
+		return 0;
+
+	/* In regular operation (SBL_EN=1) core must be 4x transfer clock */
+	ret = dev_pm_opp_set_rate(ctrl->dev, speed_hz * 4);
+	if (ret) {
+		dev_err(ctrl->dev, "Failed to set core clk %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Set BW quota for CPU.
+	 * We don't have explicit peak requirement so keep it equal to avg_bw.
+	 */
+	avg_bw_cpu = Bps_to_icc(speed_hz);
+	ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, avg_bw_cpu, avg_bw_cpu);
+	if (ret) {
+		dev_err(ctrl->dev, "%s: ICC BW voting failed for cpu: %d\n",
+			__func__, ret);
+		return ret;
+	}
+
+	ctrl->last_speed = speed_hz;
+
+	return 0;
+}
+
+static int qcom_qspi_alloc_desc(struct qcom_qspi *ctrl, dma_addr_t dma_ptr,
+			uint32_t n_bytes)
+{
+	struct qspi_cmd_desc *virt_cmd_desc, *prev;
+	dma_addr_t dma_cmd_desc;
+
+	/* allocate for dma cmd descriptor */
+	virt_cmd_desc = dma_pool_alloc(ctrl->dma_cmd_pool, GFP_ATOMIC | __GFP_ZERO, &dma_cmd_desc);
+	if (!virt_cmd_desc) {
+		dev_warn_once(ctrl->dev, "Couldn't find memory for descriptor\n");
+		return -EAGAIN;
+	}
+
+	ctrl->virt_cmd_desc[ctrl->n_cmd_desc] = virt_cmd_desc;
+	ctrl->dma_cmd_desc[ctrl->n_cmd_desc] = dma_cmd_desc;
+	ctrl->n_cmd_desc++;
+
+	/* setup cmd descriptor */
+	virt_cmd_desc->data_address = dma_ptr;
+	virt_cmd_desc->direction = ctrl->xfer.dir;
+	virt_cmd_desc->multi_io_mode = qspi_buswidth_to_iomode(ctrl, ctrl->xfer.buswidth);
+	virt_cmd_desc->fragment = !ctrl->xfer.is_last;
+	virt_cmd_desc->length = n_bytes;
+
+	/* update previous descriptor */
+	if (ctrl->n_cmd_desc >= 2) {
+		prev = (ctrl->virt_cmd_desc)[ctrl->n_cmd_desc - 2];
+		prev->next_descriptor = dma_cmd_desc;
+		prev->fragment = 1;
+	}
+
+	return 0;
+}
+
+static int qcom_qspi_setup_dma_desc(struct qcom_qspi *ctrl,
+				struct spi_transfer *xfer)
+{
+	int ret;
+	struct sg_table *sgt;
+	dma_addr_t dma_ptr_sg;
+	unsigned int dma_len_sg;
+	int i;
+
+	if (ctrl->n_cmd_desc) {
+		dev_err(ctrl->dev, "Remnant dma buffers n_cmd_desc-%d\n", ctrl->n_cmd_desc);
+		return -EIO;
+	}
+
+	sgt = (ctrl->xfer.dir == QSPI_READ) ? &xfer->rx_sg : &xfer->tx_sg;
+	if (!sgt->nents || sgt->nents > QSPI_MAX_SG) {
+		dev_warn_once(ctrl->dev, "Cannot handle %d entries in scatter list\n", sgt->nents);
+		return -EAGAIN;
+	}
+
+	for (i = 0; i < sgt->nents; i++) {
+		dma_ptr_sg = sg_dma_address(sgt->sgl + i);
+		dma_len_sg = sg_dma_len(sgt->sgl + i);
+		if (!IS_ALIGNED(dma_ptr_sg, QSPI_ALIGN_REQ)) {
+			dev_warn_once(ctrl->dev, "dma_address not aligned to %d\n", QSPI_ALIGN_REQ);
+			return -EAGAIN;
+		}
+		/*
+		 * When reading with DMA the controller writes to memory 1 word
+		 * at a time. If the length isn't a multiple of 4 bytes then
+		 * the controller can clobber the things later in memory.
+		 * Fallback to PIO to be safe.
+		 */
+		if (ctrl->xfer.dir == QSPI_READ && (dma_len_sg & 0x03)) {
+			dev_warn_once(ctrl->dev, "fallback to PIO for read of size %#010x\n",
+				      dma_len_sg);
+			return -EAGAIN;
+		}
+	}
+
+	for (i = 0; i < sgt->nents; i++) {
+		dma_ptr_sg = sg_dma_address(sgt->sgl + i);
+		dma_len_sg = sg_dma_len(sgt->sgl + i);
+
+		ret = qcom_qspi_alloc_desc(ctrl, dma_ptr_sg, dma_len_sg);
+		if (ret)
+			goto cleanup;
+	}
+	return 0;
+
+cleanup:
+	for (i = 0; i < ctrl->n_cmd_desc; i++)
+		dma_pool_free(ctrl->dma_cmd_pool, ctrl->virt_cmd_desc[i],
+				  ctrl->dma_cmd_desc[i]);
+	ctrl->n_cmd_desc = 0;
+	return ret;
+}
+
+static void qcom_qspi_dma_xfer(struct qcom_qspi *ctrl)
+{
+	/* Setup new interrupts */
+	writel(DMA_CHAIN_DONE, ctrl->base + MSTR_INT_EN);
+
+	/* kick off transfer */
+	writel((u32)((ctrl->dma_cmd_desc)[0]), ctrl->base + NEXT_DMA_DESC_ADDR);
+}
+
+/* Switch to DMA if transfer length exceeds this */
+#define QSPI_MAX_BYTES_FIFO 64
+
+static bool qcom_qspi_can_dma(struct spi_controller *ctlr,
+			 struct spi_device *slv, struct spi_transfer *xfer)
+{
+	return xfer->len > QSPI_MAX_BYTES_FIFO;
+}
+
+static int qcom_qspi_transfer_one(struct spi_controller *host,
+				  struct spi_device *slv,
+				  struct spi_transfer *xfer)
+{
+	struct qcom_qspi *ctrl = spi_controller_get_devdata(host);
+	int ret;
+	unsigned long speed_hz;
+	unsigned long flags;
+	u32 mstr_cfg;
+
+	speed_hz = slv->max_speed_hz;
+	if (xfer->speed_hz)
+		speed_hz = xfer->speed_hz;
+
+	ret = qcom_qspi_set_speed(ctrl, speed_hz);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&ctrl->lock, flags);
+	mstr_cfg = readl(ctrl->base + MSTR_CONFIG);
+
+	/* 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,
+					  &host->cur_msg->transfers);
+	ctrl->xfer.rem_bytes = xfer->len;
+
+	if (xfer->rx_sg.nents || xfer->tx_sg.nents) {
+		/* do DMA transfer */
+		if (!(mstr_cfg & DMA_ENABLE)) {
+			mstr_cfg |= DMA_ENABLE;
+			writel(mstr_cfg, ctrl->base + MSTR_CONFIG);
+		}
+
+		ret = qcom_qspi_setup_dma_desc(ctrl, xfer);
+		if (ret != -EAGAIN) {
+			if (!ret) {
+				dma_wmb();
+				qcom_qspi_dma_xfer(ctrl);
+			}
+			goto exit;
+		}
+		dev_warn_once(ctrl->dev, "DMA failure, falling back to PIO\n");
+		ret = 0; /* We'll retry w/ PIO */
+	}
+
+	if (mstr_cfg & DMA_ENABLE) {
+		mstr_cfg &= ~DMA_ENABLE;
+		writel(mstr_cfg, ctrl->base + MSTR_CONFIG);
+	}
+	qcom_qspi_pio_xfer(ctrl);
+
+exit:
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+
+	if (ret)
+		return ret;
+
+	/* We'll call spi_finalize_current_transfer() when done */
+	return 1;
+}
+
+static int qcom_qspi_prepare_message(struct spi_controller *host,
+				     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_controller_get_devdata(host);
+	spin_lock_irqsave(&ctrl->lock, flags);
+
+	mstr_cfg = readl(ctrl->base + MSTR_CONFIG);
+	mstr_cfg &= ~CHIP_SELECT_NUM;
+	if (spi_get_chipselect(message->spi, 0))
+		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 int qcom_qspi_alloc_dma(struct qcom_qspi *ctrl)
+{
+	ctrl->dma_cmd_pool = dmam_pool_create("qspi cmd desc pool",
+		ctrl->dev, sizeof(struct qspi_cmd_desc), 0, 0);
+	if (!ctrl->dma_cmd_pool)
+		return -ENOMEM;
+
+	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;
+
+	spin_lock(&ctrl->lock);
+
+	int_status = readl(ctrl->base + MSTR_INT_STATUS);
+	writel(int_status, ctrl->base + MSTR_INT_STATUS);
+
+	/* Ignore disabled interrupts */
+	int_status &= readl(ctrl->base + MSTR_INT_EN);
+
+	/* PIO mode handling */
+	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));
+	}
+
+	/* DMA mode handling */
+	if (int_status & DMA_CHAIN_DONE) {
+		int i;
+
+		writel(0, ctrl->base + MSTR_INT_EN);
+		ctrl->xfer.rem_bytes = 0;
+
+		for (i = 0; i < ctrl->n_cmd_desc; i++)
+			dma_pool_free(ctrl->dma_cmd_pool, ctrl->virt_cmd_desc[i],
+					  ctrl->dma_cmd_desc[i]);
+		ctrl->n_cmd_desc = 0;
+
+		ret = IRQ_HANDLED;
+		spi_finalize_current_transfer(dev_get_drvdata(ctrl->dev));
+	}
+
+	spin_unlock(&ctrl->lock);
+	return ret;
+}
+
+static int qcom_qspi_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
+{
+	/*
+	 * If qcom_qspi_can_dma() is going to return false we don't need to
+	 * adjust anything.
+	 */
+	if (op->data.nbytes <= QSPI_MAX_BYTES_FIFO)
+		return 0;
+
+	/*
+	 * When reading, the transfer needs to be a multiple of 4 bytes so
+	 * shrink the transfer if that's not true. The caller will then do a
+	 * second transfer to finish things up.
+	 */
+	if (op->data.dir == SPI_MEM_DATA_IN && (op->data.nbytes & 0x3))
+		op->data.nbytes &= ~0x3;
+
+	return 0;
+}
+
+static const struct spi_controller_mem_ops qcom_qspi_mem_ops = {
+	.adjust_op_size = qcom_qspi_adjust_op_size,
+};
+
+static int qcom_qspi_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct device *dev;
+	struct spi_controller *host;
+	struct qcom_qspi *ctrl;
+
+	dev = &pdev->dev;
+
+	host = devm_spi_alloc_host(dev, sizeof(*ctrl));
+	if (!host)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, host);
+
+	ctrl = spi_controller_get_devdata(host);
+
+	spin_lock_init(&ctrl->lock);
+	ctrl->dev = dev;
+	ctrl->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ctrl->base))
+		return PTR_ERR(ctrl->base);
+
+	ctrl->clks = devm_kcalloc(dev, QSPI_NUM_CLKS,
+				  sizeof(*ctrl->clks), GFP_KERNEL);
+	if (!ctrl->clks)
+		return -ENOMEM;
+
+	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)
+		return ret;
+
+	ctrl->icc_path_cpu_to_qspi = devm_of_icc_get(dev, "qspi-config");
+	if (IS_ERR(ctrl->icc_path_cpu_to_qspi))
+		return dev_err_probe(dev, PTR_ERR(ctrl->icc_path_cpu_to_qspi),
+				     "Failed to get cpu path\n");
+
+	/* Set BW vote for register access */
+	ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, Bps_to_icc(1000),
+				Bps_to_icc(1000));
+	if (ret) {
+		dev_err(ctrl->dev, "%s: ICC BW voting failed for cpu: %d\n",
+				__func__, ret);
+		return ret;
+	}
+
+	ret = icc_disable(ctrl->icc_path_cpu_to_qspi);
+	if (ret) {
+		dev_err(ctrl->dev, "%s: ICC disable failed for cpu: %d\n",
+				__func__, ret);
+		return ret;
+	}
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+	ret = devm_request_irq(dev, ret, qcom_qspi_irq, 0, dev_name(dev), ctrl);
+	if (ret) {
+		dev_err(dev, "Failed to request irq %d\n", ret);
+		return ret;
+	}
+
+	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+	if (ret)
+		return dev_err_probe(dev, ret, "could not set DMA mask\n");
+
+	host->max_speed_hz = 300000000;
+	host->max_dma_len = 65536; /* as per HPG */
+	host->dma_alignment = QSPI_ALIGN_REQ;
+	host->num_chipselect = QSPI_NUM_CS;
+	host->bus_num = -1;
+	host->dev.of_node = pdev->dev.of_node;
+	host->mode_bits = SPI_MODE_0 |
+			  SPI_TX_DUAL | SPI_RX_DUAL |
+			  SPI_TX_QUAD | SPI_RX_QUAD;
+	host->flags = SPI_CONTROLLER_HALF_DUPLEX;
+	host->prepare_message = qcom_qspi_prepare_message;
+	host->transfer_one = qcom_qspi_transfer_one;
+	host->handle_err = qcom_qspi_handle_err;
+	if (of_property_read_bool(pdev->dev.of_node, "iommus"))
+		host->can_dma = qcom_qspi_can_dma;
+	host->auto_runtime_pm = true;
+	host->mem_ops = &qcom_qspi_mem_ops;
+
+	ret = devm_pm_opp_set_clkname(&pdev->dev, "core");
+	if (ret)
+		return ret;
+	/* OPP table is optional */
+	ret = devm_pm_opp_of_add_table(&pdev->dev);
+	if (ret && ret != -ENODEV) {
+		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
+		return ret;
+	}
+
+	ret = qcom_qspi_alloc_dma(ctrl);
+	if (ret)
+		return ret;
+
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_autosuspend_delay(dev, 250);
+	pm_runtime_enable(dev);
+
+	ret = spi_register_controller(host);
+	if (!ret)
+		return 0;
+
+	pm_runtime_disable(dev);
+
+	return ret;
+}
+
+static void qcom_qspi_remove(struct platform_device *pdev)
+{
+	struct spi_controller *host = platform_get_drvdata(pdev);
+
+	/* Unregister _before_ disabling pm_runtime() so we stop transfers */
+	spi_unregister_controller(host);
+
+	pm_runtime_disable(&pdev->dev);
+}
+
+static int __maybe_unused qcom_qspi_runtime_suspend(struct device *dev)
+{
+	struct spi_controller *host = dev_get_drvdata(dev);
+	struct qcom_qspi *ctrl = spi_controller_get_devdata(host);
+	int ret;
+
+	/* Drop the performance state vote */
+	dev_pm_opp_set_rate(dev, 0);
+	clk_bulk_disable_unprepare(QSPI_NUM_CLKS, ctrl->clks);
+
+	ret = icc_disable(ctrl->icc_path_cpu_to_qspi);
+	if (ret) {
+		dev_err_ratelimited(ctrl->dev, "%s: ICC disable failed for cpu: %d\n",
+			__func__, ret);
+		return ret;
+	}
+
+	pinctrl_pm_select_sleep_state(dev);
+
+	return 0;
+}
+
+static int __maybe_unused qcom_qspi_runtime_resume(struct device *dev)
+{
+	struct spi_controller *host = dev_get_drvdata(dev);
+	struct qcom_qspi *ctrl = spi_controller_get_devdata(host);
+	int ret;
+
+	pinctrl_pm_select_default_state(dev);
+
+	ret = icc_enable(ctrl->icc_path_cpu_to_qspi);
+	if (ret) {
+		dev_err_ratelimited(ctrl->dev, "%s: ICC enable failed for cpu: %d\n",
+			__func__, ret);
+		return ret;
+	}
+
+	ret = clk_bulk_prepare_enable(QSPI_NUM_CLKS, ctrl->clks);
+	if (ret)
+		return ret;
+
+	return dev_pm_opp_set_rate(dev, ctrl->last_speed * 4);
+}
+
+static int __maybe_unused qcom_qspi_suspend(struct device *dev)
+{
+	struct spi_controller *host = dev_get_drvdata(dev);
+	int ret;
+
+	ret = spi_controller_suspend(host);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_force_suspend(dev);
+	if (ret)
+		spi_controller_resume(host);
+
+	return ret;
+}
+
+static int __maybe_unused qcom_qspi_resume(struct device *dev)
+{
+	struct spi_controller *host = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pm_runtime_force_resume(dev);
+	if (ret)
+		return ret;
+
+	ret = spi_controller_resume(host);
+	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_new = qcom_qspi_remove,
+};
+module_platform_driver(qcom_qspi_driver);
+
+MODULE_DESCRIPTION("SPI driver for QSPI cores");
+MODULE_LICENSE("GPL v2");