[PATCH 2/5] spi: zynqmp-gqspi: Reset device in probe

Sean Anderson
2025-01-16T22:55:40Z

Ensure we get a clean slate (without any bootloader settings) by
resetting the device before we initialize it.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
---

drivers/spi/spi-zynqmp-gqspi.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index 549a6e0c9654..7d138f45b692 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -17,6 +17,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include <linux/spi/spi.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
@@ -171,6 +172,7 @@ struct qspi_platform_data {
* @regs: Virtual address of the QSPI controller registers
* @refclk: Pointer to the peripheral clock
* @pclk: Pointer to the APB clock
+ * @reset: Pointer to reset controller
* @irq: IRQ number
* @dev: Pointer to struct device
* @txbuf: Pointer to the TX buffer
@@ -193,6 +195,7 @@ struct zynqmp_qspi {
void __iomem *regs;
struct clk *refclk;
struct clk *pclk;
+ struct reset_control *reset;
int irq;
struct device *dev;
const void *txbuf;
@@ -351,10 +354,17 @@ static void zynqmp_qspi_set_tapdelay(struct zynqmp_qspi *xqspi, u32 baudrateval)
* - Set clock polarity and
* - Enable the QSPI controller
*/
-static void zynqmp_qspi_init_hw(struct zynqmp_qspi *xqspi)
+static int zynqmp_qspi_init_hw(struct zynqmp_qspi *xqspi)
{
u32 config_reg, baud_rate_val = 0;
ulong clk_rate;
+ int ret;
+
+ ret = reset_control_reset(xqspi->reset);
+ if (ret) {
+ dev_err(xqspi->dev, "Unable to reset: %pe\n", &ret);
+ return ret;
+ }

/* Select the GQSPI mode */
zynqmp_gqspi_write(xqspi, GQSPI_SEL_OFST, GQSPI_SEL_MASK);
@@ -436,6 +446,8 @@ static void zynqmp_qspi_init_hw(struct zynqmp_qspi *xqspi)

/* Enable the GQSPI */
zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);
+
+ return 0;
}

/**
@@ -1259,6 +1271,12 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
if (IS_ERR(xqspi->regs))
return PTR_ERR(xqspi->regs);

+ xqspi->reset =
+ devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
+ if (IS_ERR(xqspi->reset))
+ return dev_err_probe(dev, PTR_ERR(xqspi->reset),
+ "could not get reset\n");
+
xqspi->pclk = devm_clk_get(&pdev->dev, "pclk");
if (IS_ERR(xqspi->pclk))
return dev_err_probe(dev, PTR_ERR(xqspi->pclk),
@@ -1300,7 +1318,9 @@ static int zynqmp_qspi_probe(struct platform_device *pdev)
xqspi->speed_hz = ctlr->max_speed_hz;

/* QSPI controller initializations */
- zynqmp_qspi_init_hw(xqspi);
+ ret = zynqmp_qspi_init_hw(xqspi);
+ if (ret)
+ goto clk_dis_all;

xqspi->irq = platform_get_irq(pdev, 0);
if (xqspi->irq < 0) {
--
2.35.1.1320.gc452695387.dirty