diff mbox series

[2/2] spi: atmel-quadspi: Add cs_hold and cs_inactive setting support

Message ID 20240918082744.379610-3-ada@thorsis.com (mailing list archive)
State Accepted
Commit 625de1881b5aee6a42a3130004e47dbd632429f8
Headers show
Series spi: atmel-quadspi: Fix and add full CS delay support | expand

Commit Message

Alexander Dahl Sept. 18, 2024, 8:27 a.m. UTC
spi-cs-inactive-delay-ns in dts is cs_inactive in spi core, and it maps
to DLYCS (Minimum Inactive QCS Delay) in QSPI Mode Register (QSPI_MR).

spi-cs-hold-delay-ns in dts is cs_hold in spi core, and it maps to
DLYBCT (Delay Between Consecutive Transfers) in QSPI_MR.  That one can
be set to other values than 0 only if the chip is not in Serial Memory
Mode (SMM), it must be written to '0' however when in SMM.

Tested on SAM9X60 based board with FPGA implementing custom SPI Memory
protocol.

Signed-off-by: Alexander Dahl <ada@thorsis.com>
---
 drivers/spi/atmel-quadspi.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
index fcd57cf1f2cf..d46e2ca76330 100644
--- a/drivers/spi/atmel-quadspi.c
+++ b/drivers/spi/atmel-quadspi.c
@@ -516,21 +516,45 @@  static int atmel_qspi_set_cs_timing(struct spi_device *spi)
 	struct spi_controller *ctrl = spi->controller;
 	struct atmel_qspi *aq = spi_controller_get_devdata(ctrl);
 	unsigned long clk_rate;
+	u32 cs_inactive;
 	u32 cs_setup;
+	u32 cs_hold;
 	int delay;
 	int ret;
 
-	delay = spi_delay_to_ns(&spi->cs_setup, NULL);
-	if (delay <= 0)
-		return delay;
-
 	clk_rate = clk_get_rate(aq->pclk);
 	if (!clk_rate)
 		return -EINVAL;
 
+	/* hold */
+	delay = spi_delay_to_ns(&spi->cs_hold, NULL);
+	if (aq->mr & QSPI_MR_SMM) {
+		if (delay > 0)
+			dev_warn(&aq->pdev->dev,
+				 "Ignoring cs_hold, must be 0 in Serial Memory Mode.\n");
+		cs_hold = 0;
+	} else {
+		delay = spi_delay_to_ns(&spi->cs_hold, NULL);
+		if (delay < 0)
+			return delay;
+
+		cs_hold = DIV_ROUND_UP((delay * DIV_ROUND_UP(clk_rate, 1000000)), 32000);
+	}
+
+	/* setup */
+	delay = spi_delay_to_ns(&spi->cs_setup, NULL);
+	if (delay < 0)
+		return delay;
+
 	cs_setup = DIV_ROUND_UP((delay * DIV_ROUND_UP(clk_rate, 1000000)),
 				1000);
 
+	/* inactive */
+	delay = spi_delay_to_ns(&spi->cs_inactive, NULL);
+	if (delay < 0)
+		return delay;
+	cs_inactive = DIV_ROUND_UP((delay * DIV_ROUND_UP(clk_rate, 1000000)), 1000);
+
 	ret = pm_runtime_resume_and_get(ctrl->dev.parent);
 	if (ret < 0)
 		return ret;
@@ -539,6 +563,10 @@  static int atmel_qspi_set_cs_timing(struct spi_device *spi)
 	aq->scr |= QSPI_SCR_DLYBS(cs_setup);
 	atmel_qspi_write(aq->scr, aq, QSPI_SCR);
 
+	aq->mr &= ~(QSPI_MR_DLYBCT_MASK | QSPI_MR_DLYCS_MASK);
+	aq->mr |= QSPI_MR_DLYBCT(cs_hold) | QSPI_MR_DLYCS(cs_inactive);
+	atmel_qspi_write(aq->mr, aq, QSPI_MR);
+
 	pm_runtime_mark_last_busy(ctrl->dev.parent);
 	pm_runtime_put_autosuspend(ctrl->dev.parent);