[PATCH v7 13/14] spi: mxic: Add support for direct mapping

Miquel Raynal
2021-12-17T17:27:47Z

Implement the ->dirmap_create() and ->dirmap_read/write() hooks to
provide a fast path for read and write accesses.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Tested-by: Zhengxun Li <zhengxunli@mxic.com.tw>
Reviewed-by: Zhengxun Li <zhengxunli@mxic.com.tw>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
drivers/spi/spi-mxic.c | 112 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 109 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index 52fe1060d940..97de058d2f80 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -172,6 +172,11 @@ struct mxic_spi {
struct clk *send_dly_clk;
void __iomem *regs;
u32 cur_speed_hz;
+ struct {
+ void __iomem *map;
+ dma_addr_t dma;
+ size_t size;
+ } linear;
};

static int mxic_spi_clk_enable(struct mxic_spi *mxic)
@@ -296,7 +301,8 @@ static u32 mxic_spi_prep_hc_cfg(struct spi_device *spi, u32 flags)
HC_CFG_SLV_ACT(spi->chip_select) | HC_CFG_IDLE_SIO_LVL(1);
}

-static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op)
+static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op,
+ unsigned int data_len)
{
u32 cfg = OP_CMD_BYTES(op->cmd.nbytes) |
OP_CMD_BUSW(fls(op->cmd.buswidth) - 1) |
@@ -310,7 +316,8 @@ static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op)
if (op->dummy.nbytes)
cfg |= OP_DUMMY_CYC(op->dummy.nbytes);

- if (op->data.nbytes) {
+ /* Direct mapping data.nbytes field is not populated */
+ if (data_len) {
cfg |= OP_DATA_BUSW(fls(op->data.buswidth) - 1) |
(op->data.dtr ? OP_DATA_DDR : 0);
if (op->data.dir == SPI_MEM_DATA_IN) {
@@ -371,6 +378,77 @@ static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
return 0;
}

+static ssize_t mxic_spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
+ u64 offs, size_t len, void *buf)
+{
+ struct mxic_spi *mxic = spi_master_get_devdata(desc->mem->spi->master);
+ int ret;
+ u32 sts;
+
+ if (WARN_ON(offs + desc->info.offset + len > U32_MAX))
+ return -EINVAL;
+
+ writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0), mxic->regs + HC_CFG);
+
+ writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl, len),
+ mxic->regs + LRD_CFG);
+ writel(desc->info.offset + offs, mxic->regs + LRD_ADDR);
+ len = min_t(size_t, len, mxic->linear.size);
+ writel(len, mxic->regs + LRD_RANGE);
+ writel(LMODE_CMD0(desc->info.op_tmpl.cmd.opcode) |
+ LMODE_SLV_ACT(desc->mem->spi->chip_select) |
+ LMODE_EN,
+ mxic->regs + LRD_CTRL);
+
+ memcpy_fromio(buf, mxic->linear.map, len);
+
+ writel(INT_LRD_DIS, mxic->regs + INT_STS);
+ writel(0, mxic->regs + LRD_CTRL);
+
+ ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
+ sts & INT_LRD_DIS, 0, USEC_PER_SEC);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static ssize_t mxic_spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
+ u64 offs, size_t len,
+ const void *buf)
+{
+ struct mxic_spi *mxic = spi_master_get_devdata(desc->mem->spi->master);
+ u32 sts;
+ int ret;
+
+ if (WARN_ON(offs + desc->info.offset + len > U32_MAX))
+ return -EINVAL;
+
+ writel(mxic_spi_prep_hc_cfg(desc->mem->spi, 0), mxic->regs + HC_CFG);
+
+ writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl, len),
+ mxic->regs + LWR_CFG);
+ writel(desc->info.offset + offs, mxic->regs + LWR_ADDR);
+ len = min_t(size_t, len, mxic->linear.size);
+ writel(len, mxic->regs + LWR_RANGE);
+ writel(LMODE_CMD0(desc->info.op_tmpl.cmd.opcode) |
+ LMODE_SLV_ACT(desc->mem->spi->chip_select) |
+ LMODE_EN,
+ mxic->regs + LWR_CTRL);
+
+ memcpy_toio(mxic->linear.map, buf, len);
+
+ writel(INT_LWR_DIS, mxic->regs + INT_STS);
+ writel(0, mxic->regs + LWR_CTRL);
+
+ ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
+ sts & INT_LWR_DIS, 0, USEC_PER_SEC);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
static bool mxic_spi_mem_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
@@ -388,6 +466,22 @@ static bool mxic_spi_mem_supports_op(struct spi_mem *mem,
return spi_mem_default_supports_op(mem, op);
}

+static int mxic_spi_mem_dirmap_create(struct spi_mem_dirmap_desc *desc)
+{
+ struct mxic_spi *mxic = spi_master_get_devdata(desc->mem->spi->master);
+
+ if (!mxic->linear.map)
+ return -EINVAL;
+
+ if (desc->info.offset + desc->info.length > U32_MAX)
+ return -EINVAL;
+
+ if (!mxic_spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
static int mxic_spi_mem_exec_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
@@ -404,7 +498,7 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,

writel(HC_EN_BIT, mxic->regs + HC_EN);

- writel(mxic_spi_mem_prep_op_cfg(op),
+ writel(mxic_spi_mem_prep_op_cfg(op, op->data.nbytes),
mxic->regs + SS_CTRL(mem->spi->chip_select));

writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_ASSERT,
@@ -450,6 +544,9 @@ static const struct spi_controller_mem_caps mxic_spi_mem_caps = {
static const struct spi_controller_mem_ops mxic_spi_mem_ops = {
.supports_op = mxic_spi_mem_supports_op,
.exec_op = mxic_spi_mem_exec_op,
+ .dirmap_create = mxic_spi_mem_dirmap_create,
+ .dirmap_read = mxic_spi_mem_dirmap_read,
+ .dirmap_write = mxic_spi_mem_dirmap_write,
.caps = &mxic_spi_mem_caps,
};

@@ -580,6 +677,15 @@ static int mxic_spi_probe(struct platform_device *pdev)
if (IS_ERR(mxic->regs))
return PTR_ERR(mxic->regs);

+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dirmap");
+ mxic->linear.map = devm_ioremap_resource(&pdev->dev, res);
+ if (!IS_ERR(mxic->linear.map)) {
+ mxic->linear.dma = res->start;
+ mxic->linear.size = resource_size(res);
+ } else {
+ mxic->linear.map = NULL;
+ }
+
pm_runtime_enable(&pdev->dev);
master->auto_runtime_pm = true;

--
2.27.0