[PATCH v3 3/3] mtd: spi-nor: cadence-quadspi: disable the auto-poll for Intel LGM

["Ramuthevar,Vadivel MuruganX" <vadivel.muruganx.ramuthevar@linux.intel.com>]

From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>

On Intel's Lightning Mountain(LGM) SoC QSPI controller do not auto-poll.
This patch introduces to properly disable the auto-polling feature to
improve the performance of cadence-quadspi.

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
---
 drivers/mtd/spi-nor/cadence-quadspi.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 73b9fbd1508a..60998eaad1cc 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -135,6 +135,8 @@ struct cqspi_driver_platdata {
 #define CQSPI_REG_RD_INSTR_TYPE_DATA_MASK	0x3
 #define CQSPI_REG_RD_INSTR_DUMMY_MASK		0x1F
 
+#define CQSPI_REG_WR_COMPLETION_CTRL		0x38
+#define CQSPI_REG_WR_COMPLETION_DISABLE_AUTO_POLL	BIT(14)
 #define CQSPI_REG_WR_INSTR			0x08
 #define CQSPI_REG_WR_INSTR_OPCODE_LSB		0
 #define CQSPI_REG_WR_INSTR_TYPE_ADDR_LSB	12
@@ -471,6 +473,18 @@ static int cqspi_command_write_addr(struct spi_nor *nor,
 	return cqspi_exec_flash_cmd(cqspi, reg);
 }
 
+static int cqspi_disable_auto_poll(struct cqspi_st *cqspi)
+{
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int reg;
+
+	reg = readl(reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
+	reg |= CQSPI_REG_WR_COMPLETION_DISABLE_AUTO_POLL;
+	writel(reg, reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
+
+	return 0;
+}
+
 static int cqspi_read_setup(struct spi_nor *nor)
 {
 	struct cqspi_flash_pdata *f_pdata = nor->priv;
@@ -508,6 +522,11 @@ static int cqspi_read_setup(struct spi_nor *nor)
 	reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
 	reg |= (nor->addr_width - 1);
 	writel(reg, reg_base + CQSPI_REG_SIZE);
+
+	/* Disable auto-polling */
+	if (!f_pdata->use_direct_mode)
+		cqspi_disable_auto_poll(cqspi);
+
 	return 0;
 }
 
@@ -627,6 +646,11 @@ static int cqspi_write_setup(struct spi_nor *nor)
 	reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
 	reg |= (nor->addr_width - 1);
 	writel(reg, reg_base + CQSPI_REG_SIZE);
+
+	/* Disable auto-polling */
+	if (!f_pdata->use_direct_mode)
+		cqspi_disable_auto_poll(cqspi);
+
 	return 0;
 }
 
-- 
2.11.0