[PATCH 5/7] spi: Add direct mapping mode for Macronix SPI controller

[Mason Yang <masonccyang@xxxxxxxxxxx>]

Add direct mapping read mode for Macronix SPI controller driver.

Signed-off-by: Mason Yang <masonccyang@xxxxxxxxxxx>
---
 drivers/spi/spi-mxic.c | 129 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 100 insertions(+), 29 deletions(-)

diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index fbebf89..9f5ff2b 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -19,6 +19,7 @@ struct mxic_spi {
 	struct clk *send_clk;
 	struct clk *send_dly_clk;
 	void __iomem *regs;
+	void __iomem *dirmap;
 	u32 cur_speed_hz;
 };
 
@@ -128,6 +129,42 @@ static void mxic_spi_hw_init(struct mxic_spi *mxic)
 	       mxic->regs + HC_CFG);
 }
 
+static u32 mxic_spi_mem_prep_op_cfg(const struct spi_mem_op *op)
+{
+	u32 cfg = OP_CMD_BYTES(1) | OP_CMD_BUSW(fls(op->cmd.buswidth) - 1);
+
+	if (op->addr.nbytes)
+		cfg |= OP_ADDR_BYTES(op->addr.nbytes) |
+		       OP_ADDR_BUSW(fls(op->addr.buswidth) - 1);
+
+	if (op->dummy.nbytes)
+		cfg |= OP_DUMMY_CYC(op->dummy.nbytes);
+
+	if (op->data.nbytes) {
+		cfg |= OP_DATA_BUSW(fls(op->data.buswidth) - 1);
+		if (op->data.dir == SPI_MEM_DATA_IN)
+			cfg |= OP_READ;
+	}
+
+	return cfg;
+}
+
+static void mxic_spi_set_hc_cfg(struct spi_device *spi, u32 flags)
+{
+	struct mxic_spi *mxic = spi_master_get_devdata(spi->master);
+	int nio = 1;
+
+	if (spi->mode & (SPI_TX_QUAD | SPI_RX_QUAD))
+		nio = 4;
+	else if (spi->mode & (SPI_TX_DUAL | SPI_RX_DUAL))
+		nio = 2;
+
+	writel(flags | HC_CFG_NIO(nio) |
+	       HC_CFG_TYPE(spi->chip_select, HC_CFG_TYPE_SPI_NOR) |
+	       HC_CFG_SLV_ACT(spi->chip_select) | HC_CFG_IDLE_SIO_LVL(1),
+	       mxic->regs + HC_CFG);
+}
+
 static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
 			      void *rxbuf, unsigned int len)
 {
@@ -201,43 +238,18 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 				const struct spi_mem_op *op)
 {
 	struct mxic_spi *mxic = spi_master_get_devdata(mem->spi->master);
-	int nio = 1, i, ret;
-	u32 ss_ctrl;
+	int i, ret;
 	u8 addr[8];
 
 	ret = mxic_spi_set_freq(mxic, mem->spi->max_speed_hz);
 	if (ret)
 		return ret;
 
-	if (mem->spi->mode & (SPI_TX_QUAD | SPI_RX_QUAD))
-		nio = 4;
-	else if (mem->spi->mode & (SPI_TX_DUAL | SPI_RX_DUAL))
-		nio = 2;
+	mxic_spi_set_hc_cfg(mem->spi, HC_CFG_MAN_CS_EN);
 
-	writel(HC_CFG_NIO(nio) |
-	       HC_CFG_TYPE(mem->spi->chip_select, HC_CFG_TYPE_SPI_NOR) |
-	       HC_CFG_SLV_ACT(mem->spi->chip_select) | HC_CFG_IDLE_SIO_LVL(1) |
-	       HC_CFG_MAN_CS_EN,
-	       mxic->regs + HC_CFG);
 	writel(HC_EN_BIT, mxic->regs + HC_EN);
-
-	ss_ctrl = OP_CMD_BYTES(1) | OP_CMD_BUSW(fls(op->cmd.buswidth) - 1);
-
-	if (op->addr.nbytes)
-		ss_ctrl |= OP_ADDR_BYTES(op->addr.nbytes) |
-			   OP_ADDR_BUSW(fls(op->addr.buswidth) - 1);
-
-	if (op->dummy.nbytes)
-		ss_ctrl |= OP_DUMMY_CYC(op->dummy.nbytes);
-
-	if (op->data.nbytes) {
-		ss_ctrl |= OP_DATA_BUSW(fls(op->data.buswidth) - 1);
-		if (op->data.dir == SPI_MEM_DATA_IN)
-			ss_ctrl |= OP_READ;
-	}
-
-	writel(ss_ctrl, mxic->regs + SS_CTRL(mem->spi->chip_select));
-
+	writel(mxic_spi_mem_prep_op_cfg(op),
+	       mxic->regs + SS_CTRL(mem->spi->chip_select));
 	writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_ASSERT,
 	       mxic->regs + HC_CFG);
 
@@ -271,9 +283,64 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 	return ret;
 }
 
+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->dirmap)
+		return -ENOTSUPP;
+
+	 /*
+	  * TODO: overcome this limitation by moving LWR/LRD_ADDR during a
+	  * read/write operation.
+	  */
+	if (desc->info.offset + desc->info.length > U32_MAX)
+		return -ENOTSUPP;
+
+	if (!mxic_spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
+		return -ENOTSUPP;
+
+	if (desc->info.op_tmpl.data.dir == SPI_MEM_DATA_OUT)
+		return -ENOTSUPP;
+
+	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;
+
+	mxic_spi_set_hc_cfg(desc->mem->spi, 0);
+
+	writel(mxic_spi_mem_prep_op_cfg(&desc->info.op_tmpl),
+	       mxic->regs + LRD_CFG);
+	writel(LMODE_CMD0(desc->info.op_tmpl.cmd.opcode >> 8) |
+	       (LMODE_CMD1(desc->info.op_tmpl.cmd.opcode) & 0xff00) |
+	       LMODE_SLV_ACT(desc->mem->spi->chip_select) |
+	       LMODE_EN, mxic->regs + LRD_CTRL);
+
+	memcpy_fromio(buf, mxic->dirmap + offs, 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 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,
 };
 
 static void mxic_spi_set_cs(struct spi_device *spi, bool lvl)
@@ -404,6 +471,10 @@ static int mxic_spi_probe(struct platform_device *pdev)
 	if (IS_ERR(mxic->regs))
 		return PTR_ERR(mxic->regs);
 
+	mxic->dirmap = mxic_mfd->dirmap;
+	if (IS_ERR(mxic->dirmap))
+		mxic->dirmap = NULL;
+
 	pm_runtime_enable(&pdev->dev);
 	master->auto_runtime_pm = true;
 
-- 
1.9.1