[V2 3/3] spi: spi-qcom-qspi: Add DMA mode support

From: Vijaya Krishna Nivarthi
Date: Wed Apr 12 2023 - 11:30:39 EST

Current driver supports only PIO mode.

HW supports DMA, so add DMA mode support to the driver
for better performance for larger xfers.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202304050512.MN2oNY9Z-lkp@xxxxxxxxx/
Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@xxxxxxxxxxx>
---
v1 -> v2:
- modified commit message
- addressed kernel test robot error
- correct placement of header file includes
- added more comments
- coding style related changes
- renamed variables
- used u32/u8 instead of uint32_t/8_t
- removed unnecessary casting
- retain same MSTR_CONFIG as PIO for DMA
---
drivers/spi/spi-qcom-qspi.c | 434 ++++++++++++++++++++++++++++++++++++++++----
1 file changed, 403 insertions(+), 31 deletions(-)

diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c
index fab1553..1b53480 100644
--- a/drivers/spi/spi-qcom-qspi.c
+++ b/drivers/spi/spi-qcom-qspi.c
@@ -2,6 +2,8 @@
// 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>
@@ -14,7 +16,6 @@
#include <linux/spi/spi.h>
#include <linux/spi/spi-mem.h>

-
#define QSPI_NUM_CS 2
#define QSPI_BYTES_PER_WORD 4

@@ -62,6 +63,7 @@
#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 | \
@@ -108,6 +110,10 @@
#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
@@ -120,6 +126,27 @@ enum qspi_dir {
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;
+ /*
+ * This marks end of HW cmd descriptor
+ * Fields down below are for SW usage to
+ * copy data from DMA buffer to rx buffer
+ */
+ u8 *bounce_src;
+ u8 *bounce_dst;
+ u32 bounce_length;
+};
+
+#define QSPI_MAX_NUM_DESC 5
+
struct qspi_xfer {
union {
const void *tx_buf;
@@ -137,11 +164,36 @@ enum qspi_clocks {
QSPI_NUM_CLKS
};

+enum qspi_xfer_mode {
+ QSPI_INVALID,
+ QSPI_FIFO,
+ QSPI_DMA
+};
+
+/* number of entries in sgt returned from spi framework that we can support */
+#define QSPI_MAX_SG 5
+
+/* 3 descriptors for head, aligned part and tail */
+#define QSPI_NUM_CMD_DESC 3
+
+/* 2 descriptors for head, tail */
+#define QSPI_NUM_DAT_DESC 2
+
struct qcom_qspi {
void __iomem *base;
struct device *dev;
struct clk_bulk_data *clks;
struct qspi_xfer xfer;
+ struct dma_pool *dma_cmd_pool;
+ struct dma_pool *dma_data_pool;
+ dma_addr_t dma_cmd_desc[QSPI_NUM_CMD_DESC*QSPI_MAX_SG];
+ dma_addr_t dma_data_desc[QSPI_NUM_DAT_DESC*QSPI_MAX_SG];
+ void *virt_cmd_desc[QSPI_NUM_CMD_DESC*QSPI_MAX_SG];
+ void *virt_data_desc[QSPI_NUM_DAT_DESC*QSPI_MAX_SG];
+ unsigned int n_cmd_desc;
+ unsigned int n_data_desc;
+ int xfer_mode;
+ u32 iomode;
struct icc_path *icc_path_cpu_to_qspi;
unsigned long last_speed;
/* Lock to protect data accessed by IRQs */
@@ -151,18 +203,25 @@ struct qcom_qspi {
static u32 qspi_buswidth_to_iomode(struct qcom_qspi *ctrl,
unsigned int buswidth)
{
+ u32 ret;
+
+ /* for DMA we don't write to PIO_XFER_CFG register, so don't shift */
switch (buswidth) {
case 1:
- return SDR_1BIT << MULTI_IO_MODE_SHFT;
+ ret = (ctrl->xfer_mode == QSPI_DMA ? SDR_1BIT : SDR_1BIT << MULTI_IO_MODE_SHFT);
+ break;
case 2:
- return SDR_2BIT << MULTI_IO_MODE_SHFT;
+ ret = (ctrl->xfer_mode == QSPI_DMA ? SDR_2BIT : SDR_2BIT << MULTI_IO_MODE_SHFT);
+ break;
case 4:
- return SDR_4BIT << MULTI_IO_MODE_SHFT;
+ ret = (ctrl->xfer_mode == QSPI_DMA ? SDR_4BIT : SDR_4BIT << MULTI_IO_MODE_SHFT);
+ break;
default:
dev_warn_once(ctrl->dev,
"Unexpected bus width: %u\n", buswidth);
- return SDR_1BIT << MULTI_IO_MODE_SHFT;
+ ret = (ctrl->xfer_mode == QSPI_DMA ? SDR_1BIT : SDR_1BIT << MULTI_IO_MODE_SHFT);
}
+ return ret;
}

static void qcom_qspi_pio_xfer_cfg(struct qcom_qspi *ctrl)
@@ -223,6 +282,21 @@ static void qcom_qspi_handle_err(struct spi_master *master,
spin_lock_irqsave(&ctrl->lock, flags);
writel(0, ctrl->base + MSTR_INT_EN);
ctrl->xfer.rem_bytes = 0;
+
+ if (ctrl->xfer_mode == QSPI_DMA) {
+ int i;
+
+ /* free cmd and data descriptors */
+ for (i = 0; i < ctrl->n_data_desc; i++)
+ dma_pool_free(ctrl->dma_data_pool, ctrl->virt_data_desc[i],
+ ctrl->dma_data_desc[i]);
+ ctrl->n_data_desc = 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;
+ }
spin_unlock_irqrestore(&ctrl->lock, flags);
}

@@ -230,6 +304,7 @@ static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz)
{
int ret;
unsigned int avg_bw_cpu;
+ unsigned int peak_bw_cpu;

if (speed_hz == ctrl->last_speed)
return 0;
@@ -241,12 +316,16 @@ static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz)
return ret;
}

+ avg_bw_cpu = Bps_to_icc(speed_hz);
/*
- * Set BW quota for CPU as driver supports FIFO mode only.
- * We don't have explicit peak requirement so keep it equal to avg_bw.
+ * Set BW quota for CPU for FIFO to avg_bw
+ * as we don't have explicit peak requirement.
+ * TBD TBD TBD - change this as required for DMA.
+ * As of now same peak requirement seems to be working.
*/
- avg_bw_cpu = Bps_to_icc(speed_hz);
- ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, avg_bw_cpu, avg_bw_cpu);
+ peak_bw_cpu = ctrl->xfer_mode == QSPI_FIFO ? avg_bw_cpu : avg_bw_cpu;
+
+ ret = icc_set_bw(ctrl->icc_path_cpu_to_qspi, avg_bw_cpu, peak_bw_cpu);
if (ret) {
dev_err(ctrl->dev, "%s: ICC BW voting failed for cpu: %d\n",
__func__, ret);
@@ -258,6 +337,190 @@ static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz)
return 0;
}

+/* aligned to 32 bytes, not to cross 1KB boundary */
+#define QSPI_ALIGN_REQ 32
+#define QSPI_BOUNDARY_REQ 1024
+
+static int qcom_qspi_alloc_desc(struct qcom_qspi *ctrl, uint8_t *virt_ptr,
+ dma_addr_t dma_ptr, uint32_t n_bytes)
+{
+ struct qspi_cmd_desc *virt_cmd_desc, *prev;
+ uint8_t *virt_data_desc;
+ dma_addr_t dma_cmd_desc, dma_data_desc;
+
+ if (virt_ptr && n_bytes >= QSPI_ALIGN_REQ) {
+ dev_err(ctrl->dev,
+ "Exiting to avert memory overwrite, n_bytes-%d\n", n_bytes);
+ return -ENOMEM;
+ }
+
+ /* allocate for dma cmd descriptor */
+ virt_cmd_desc = (struct qspi_cmd_desc *)dma_pool_alloc(ctrl->dma_cmd_pool,
+ GFP_KERNEL, &dma_cmd_desc);
+ if (!virt_cmd_desc) {
+ dev_err(ctrl->dev,
+ "Could not allocate for cmd_desc\n");
+ return -ENOMEM;
+ }
+ 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++;
+
+ /* allocate for dma data descriptor if unaligned else use pre-aligned */
+ if (virt_ptr) {
+ virt_data_desc = (uint8_t *)dma_pool_zalloc(ctrl->dma_data_pool,
+ GFP_KERNEL, &dma_data_desc);
+ if (!virt_data_desc) {
+ dev_err(ctrl->dev,
+ "Could not allocate for data_desc\n");
+ return -ENOMEM;
+ }
+ ctrl->virt_data_desc[ctrl->n_data_desc] = virt_data_desc;
+ ctrl->dma_data_desc[ctrl->n_data_desc] = dma_data_desc;
+ ctrl->n_data_desc++;
+
+ /*
+ * for tx copy xfer data into allocated buffer
+ * for rx setup bounce info to copy after xfer
+ */
+ if (ctrl->xfer.dir == QSPI_WRITE) {
+ memcpy(virt_data_desc, virt_ptr, n_bytes);
+ } else {
+ virt_cmd_desc->bounce_src = virt_data_desc;
+ virt_cmd_desc->bounce_dst = virt_ptr;
+ virt_cmd_desc->bounce_length = n_bytes;
+ }
+ } else {
+ dma_data_desc = dma_ptr;
+ }
+
+ /* setup cmd descriptor */
+ virt_cmd_desc->data_address = dma_data_desc;
+ virt_cmd_desc->next_descriptor = 0;
+ virt_cmd_desc->direction = ctrl->xfer.dir;
+ virt_cmd_desc->multi_io_mode = ctrl->iomode;
+ virt_cmd_desc->reserved1 = 0;
+ virt_cmd_desc->fragment = 0;
+ virt_cmd_desc->reserved2 = 0;
+ 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;
+ unsigned int sg_total_len = 0;
+ dma_addr_t dma_ptr_sg;
+ unsigned int dma_len_sg;
+ uint32_t prolog_bytes, aligned_bytes, epilog_bytes;
+ dma_addr_t aligned_addr;
+ int i;
+ uint8_t *byte_ptr;
+
+ if (ctrl->n_cmd_desc || ctrl->n_data_desc) {
+ dev_err(ctrl->dev, "Remnant dma buffers cmd-%d, data-%d\n",
+ ctrl->n_cmd_desc, ctrl->n_data_desc);
+ return -EIO;
+ }
+
+ sgt = (ctrl->xfer.dir == QSPI_READ) ? &xfer->rx_sg : &xfer->tx_sg;
+ if (!sgt->nents || sgt->nents > QSPI_MAX_SG) {
+ dev_err(ctrl->dev, "Cannot handle %d entries in scatter list\n", sgt->nents);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < sgt->nents; i++)
+ sg_total_len += sg_dma_len(sgt->sgl + i);
+ if (sg_total_len != xfer->len) {
+ dev_err(ctrl->dev, "Data lengths mismatch\n");
+ return -EINVAL;
+ }
+
+ if (ctrl->xfer.dir == QSPI_READ)
+ byte_ptr = xfer->rx_buf;
+ else
+ byte_ptr = (uint8_t *)xfer->tx_buf;
+
+ 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);
+
+ aligned_addr = PTR_ALIGN(dma_ptr_sg, QSPI_ALIGN_REQ);
+
+ prolog_bytes = min(dma_len_sg, (unsigned int)(aligned_addr - dma_ptr_sg));
+ if (prolog_bytes) {
+ ret = qcom_qspi_alloc_desc(ctrl, byte_ptr, 0, prolog_bytes);
+ if (ret)
+ goto cleanup;
+ byte_ptr += prolog_bytes;
+ }
+
+ aligned_bytes = PTR_ALIGN_DOWN(dma_len_sg - prolog_bytes, QSPI_ALIGN_REQ);
+ if (aligned_bytes) {
+ ret = qcom_qspi_alloc_desc(ctrl, 0, aligned_addr, aligned_bytes);
+ if (ret)
+ goto cleanup;
+ byte_ptr += aligned_bytes;
+ }
+
+ epilog_bytes = dma_len_sg - prolog_bytes - aligned_bytes;
+ if (epilog_bytes) {
+ ret = qcom_qspi_alloc_desc(ctrl, byte_ptr, 0, epilog_bytes);
+ if (ret)
+ goto cleanup;
+ byte_ptr += epilog_bytes;
+ }
+ }
+ return 0;
+
+cleanup:
+ dev_err(ctrl->dev, "ERROR cleanup in setup_dma_desc\n");
+ for (i = 0; i < ctrl->n_data_desc; i++)
+ dma_pool_free(ctrl->dma_data_pool, ctrl->virt_data_desc[i],
+ ctrl->dma_data_desc[i]);
+ ctrl->n_data_desc = 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;
+ return ret;
+}
+
+static void qcom_qspi_dma_xfer(struct qcom_qspi *ctrl)
+{
+ /* Ack any previous interrupts that might be hanging around */
+ writel(DMA_CHAIN_DONE, ctrl->base + MSTR_INT_STATUS);
+
+ /* Setup new interrupts */
+ writel(DMA_CHAIN_DONE, ctrl->base + MSTR_INT_EN);
+
+ /* flush all writes */
+ wmb();
+
+ /* kick off transfer */
+ writel((uint32_t)(uintptr_t)(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 ? true : false;
+}
+
static int qcom_qspi_transfer_one(struct spi_master *master,
struct spi_device *slv,
struct spi_transfer *xfer)
@@ -266,6 +529,7 @@ static int qcom_qspi_transfer_one(struct spi_master *master,
int ret;
unsigned long speed_hz;
unsigned long flags;
+ u32 mstr_cfg;

speed_hz = slv->max_speed_hz;
if (xfer->speed_hz)
@@ -276,6 +540,7 @@ static int qcom_qspi_transfer_one(struct spi_master *master,
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) {
@@ -290,7 +555,25 @@ static int qcom_qspi_transfer_one(struct spi_master *master,
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);
+
+ if (qcom_qspi_can_dma(master, slv, xfer)) {
+ ctrl->xfer_mode = QSPI_DMA;
+ ctrl->iomode = qspi_buswidth_to_iomode(ctrl, ctrl->xfer.buswidth);
+ mstr_cfg |= DMA_ENABLE;
+ writel(mstr_cfg, ctrl->base + MSTR_CONFIG);
+
+ ret = qcom_qspi_setup_dma_desc(ctrl, xfer);
+ if (ret) {
+ spin_unlock_irqrestore(&ctrl->lock, flags);
+ return ret;
+ }
+ qcom_qspi_dma_xfer(ctrl);
+ } else {
+ ctrl->xfer_mode = QSPI_FIFO;
+ mstr_cfg &= ~DMA_ENABLE;
+ writel(mstr_cfg, ctrl->base + MSTR_CONFIG);
+ qcom_qspi_pio_xfer(ctrl);
+ }

spin_unlock_irqrestore(&ctrl->lock, flags);

@@ -328,6 +611,40 @@ static int qcom_qspi_prepare_message(struct spi_master *master,
return 0;
}

+static int qcom_qspi_alloc_dma(struct qcom_qspi *ctrl)
+{
+ /* allocate for cmd descriptors pool */
+ ctrl->dma_cmd_pool = dma_pool_create("qspi cmd desc pool",
+ ctrl->dev, sizeof(struct qspi_cmd_desc), 0, 0);
+ if (!ctrl->dma_cmd_pool) {
+ dev_err(ctrl->dev, "Could not create dma pool for cmd_desc\n");
+ return -ENOMEM;
+ }
+
+ /*
+ * allocate for data descriptors pool as per alignment
+ * and boundary requirements
+ */
+ ctrl->dma_data_pool = dma_pool_create("qspi data desc pool",
+ ctrl->dev, QSPI_ALIGN_REQ, QSPI_ALIGN_REQ, QSPI_BOUNDARY_REQ);
+ if (!ctrl->dma_data_pool) {
+ dev_err(ctrl->dev, "Could not create dma pool for data desc\n");
+ dma_pool_destroy(ctrl->dma_cmd_pool);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static void qcom_qspi_free_dma(struct qcom_qspi *ctrl)
+{
+ /* free pool buffers */
+ dma_pool_destroy(ctrl->dma_data_pool);
+
+ /* free pool */
+ dma_pool_destroy(ctrl->dma_cmd_pool);
+}
+
static irqreturn_t pio_read(struct qcom_qspi *ctrl)
{
u32 rd_fifo_status;
@@ -426,27 +743,63 @@ static irqreturn_t qcom_qspi_irq(int irq, void *dev_id)
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));
+ switch (ctrl->xfer_mode) {
+ case QSPI_FIFO:
+ 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));
+ }
+ break;
+ case QSPI_DMA:
+ if (int_status & DMA_CHAIN_DONE) {
+ int i;
+
+ writel(0, ctrl->base + MSTR_INT_EN);
+
+ if (ctrl->xfer.dir == QSPI_READ) {
+ struct qspi_cmd_desc *cmd_desc;
+
+ for (i = 0; i < ctrl->n_cmd_desc; i++) {
+ cmd_desc = (struct qspi_cmd_desc *)ctrl->virt_cmd_desc[i];
+ memcpy(cmd_desc->bounce_dst,
+ cmd_desc->bounce_src, cmd_desc->bounce_length);
+ }
+ }
+
+ for (i = 0; i < ctrl->n_data_desc; i++)
+ dma_pool_free(ctrl->dma_data_pool, ctrl->virt_data_desc[i],
+ ctrl->dma_data_desc[i]);
+ ctrl->n_data_desc = 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));
+ }
+ break;
+ default:
+ dev_err(ctrl->dev, "Unknown xfer mode:%d", ctrl->xfer_mode);
}

spin_unlock(&ctrl->lock);
@@ -487,6 +840,9 @@ static int qcom_qspi_probe(struct platform_device *pdev)
if (ret)
return ret;

+ /* set default mode to FIFO */
+ ctrl->xfer_mode = QSPI_FIFO;
+
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),
@@ -517,7 +873,12 @@ static int qcom_qspi_probe(struct platform_device *pdev)
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");
+
master->max_speed_hz = 300000000;
+ master->max_dma_len = 65536; /* as per HPG */
master->num_chipselect = QSPI_NUM_CS;
master->bus_num = -1;
master->dev.of_node = pdev->dev.of_node;
@@ -528,6 +889,7 @@ static int qcom_qspi_probe(struct platform_device *pdev)
master->prepare_message = qcom_qspi_prepare_message;
master->transfer_one = qcom_qspi_transfer_one;
master->handle_err = qcom_qspi_handle_err;
+ master->can_dma = qcom_qspi_can_dma;
master->auto_runtime_pm = true;

ret = devm_pm_opp_set_clkname(&pdev->dev, "core");
@@ -540,6 +902,11 @@ static int qcom_qspi_probe(struct platform_device *pdev)
return ret;
}

+ /* allocate for DMA descriptor pools */
+ 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);
@@ -556,10 +923,15 @@ static int qcom_qspi_probe(struct platform_device *pdev)
static void qcom_qspi_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
+ struct qcom_qspi *ctrl;
+
+ ctrl = spi_master_get_devdata(master);

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

+ qcom_qspi_free_dma(ctrl);
+
pm_runtime_disable(&pdev->dev);
}

--
Qualcomm INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by the Linux Foundation.