linux-kernel - [PATCH v2 2/7] spi: spi-zynqmp-gqspi: Set CPOL and CPHA during hardware init

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Message-ID: <20220915120750.1424984-3-amit.kumar-mahapatra@xilinx.com>
Date:   Thu, 15 Sep 2022 17:37:45 +0530
From:   Amit Kumar Mahapatra <amit.kumar-mahapatra@...inx.com>
To:     <broonie@...nel.org>, <robh+dt@...nel.org>,
        <krzysztof.kozlowski+dt@...aro.org>
CC:     <git@....com>, <michal.simek@....com>, <linux-spi@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <akumarma@....com>,
        Amit Kumar Mahapatra <amit.kumar-mahapatra@...inx.com>
Subject: [PATCH v2 2/7] spi: spi-zynqmp-gqspi: Set CPOL and CPHA during hardware init

During every transfer GQSPI driver writes the CPOL & CPHA values to the
configuration register. But the CPOL & CPHA values do not change in between
multiple transfers, so moved the CPOL & CPHA initialization to hardware
init so that the values are written only once.

Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@...inx.com>
---
 drivers/spi/spi-zynqmp-gqspi.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index b07bb97cf874..6771496c1f86 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -264,7 +264,9 @@ static void zynqmp_gqspi_selectslave(struct zynqmp_qspi *instanceptr,
  *	- Enable manual slave select
  *	- Enable manual start
  *	- Deselect all the chip select lines
- *	- Set the little endian mode of TX FIFO and
+ *	- Set the little endian mode of TX FIFO
+ *	- Set clock phase
+ *	- Set clock polarity and
  *	- Enable the QSPI controller
  */
 static void zynqmp_qspi_init_hw(struct zynqmp_qspi *xqspi)
@@ -303,10 +305,17 @@ static void zynqmp_qspi_init_hw(struct zynqmp_qspi *xqspi)
 	config_reg |= GQSPI_CFG_WP_HOLD_MASK;
 	/* Clear pre-scalar by default */
 	config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK;
-	/* CPHA 0 */
-	config_reg &= ~GQSPI_CFG_CLK_PHA_MASK;
-	/* CPOL 0 */
-	config_reg &= ~GQSPI_CFG_CLK_POL_MASK;
+	/* Set CPHA */
+	if (xqspi->ctlr->mode_bits & SPI_CPHA)
+		config_reg |= GQSPI_CFG_CLK_PHA_MASK;
+	else
+		config_reg &= ~GQSPI_CFG_CLK_PHA_MASK;
+	/* Set CPOL */
+	if (xqspi->ctlr->mode_bits & SPI_CPOL)
+		config_reg |= GQSPI_CFG_CLK_POL_MASK;
+	else
+		config_reg &= ~GQSPI_CFG_CLK_POL_MASK;
+
 	zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
 
 	/* Clear the TX and RX FIFO */
@@ -463,14 +472,6 @@ static int zynqmp_qspi_config_op(struct zynqmp_qspi *xqspi,
 
 	config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
 
-	/* Set the QSPI clock phase and clock polarity */
-	config_reg &= (~GQSPI_CFG_CLK_PHA_MASK) & (~GQSPI_CFG_CLK_POL_MASK);
-
-	if (qspi->mode & SPI_CPHA)
-		config_reg |= GQSPI_CFG_CLK_PHA_MASK;
-	if (qspi->mode & SPI_CPOL)
-		config_reg |= GQSPI_CFG_CLK_POL_MASK;
-
 	config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK;
 	config_reg |= (baud_rate_val << GQSPI_CFG_BAUD_RATE_DIV_SHIFT);
 	zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
@@ -1162,6 +1163,9 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
 		goto clk_dis_all;
 	}
 
+	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD |
+		SPI_TX_DUAL | SPI_TX_QUAD;
+
 	/* QSPI controller initializations */
 	zynqmp_qspi_init_hw(xqspi);
 
@@ -1188,8 +1192,6 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
 	ctlr->setup = zynqmp_qspi_setup_op;
 	ctlr->max_speed_hz = clk_get_rate(xqspi->refclk) / 2;
 	ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
-	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD |
-			    SPI_TX_DUAL | SPI_TX_QUAD;
 	ctlr->dev.of_node = np;
 	ctlr->auto_runtime_pm = true;
 
-- 
2.25.1