2022-10-11 06:23:21

by Mahapatra, Amit Kumar

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Subject: [PATCH v4 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 <[email protected]>
---
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 973008a30a09..1b56dd29057f 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -266,7 +266,9 @@ 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)
@@ -305,10 +307,17 @@ 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 */
@@ -470,14 +479,6 @@ 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);
@@ -1170,6 +1171,9 @@ 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);

@@ -1207,8 +1211,6 @@ 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;

--
2.17.1