spi: mxic: Add support for direct mapping

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>
Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-13-miquel.raynal@bootlin.com

diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index ba9cda4bf161283c4a4532666948b7c3dea25d03..0d3390964c6fb4cd734c089cff4fd557a178ae97 100644 (file)
--- 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,
@@ -446,6 +540,9 @@ out:
 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,
 };
 
 static const struct spi_controller_mem_caps mxic_spi_mem_caps = {
@@ -579,6 +676,15 @@ 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;