[PATCH v3 1/4] spi: bcm63xx-spi: add reset support

Álvaro Fernández Rojas
2020-06-16T07:02:36Z

bcm63xx arch resets the SPI controller at early boot. However, bmips arch
needs to perform a reset when probing the driver.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
---
v3: use devm_reset_control_get_optional_exclusive
v2: use devm_reset_control_get_exclusive

drivers/spi/spi-bcm63xx.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c
index 0f1b10a4ef0c..92e88901189c 100644
--- a/drivers/spi/spi-bcm63xx.c
+++ b/drivers/spi/spi-bcm63xx.c
@@ -18,6 +18,7 @@
#include <linux/err.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
+#include <linux/reset.h>

/* BCM 6338/6348 SPI core */
#define SPI_6348_RSET_SIZE 64
@@ -493,6 +494,7 @@ static int bcm63xx_spi_probe(struct platform_device *pdev)
struct bcm63xx_spi *bs;
int ret;
u32 num_cs = BCM63XX_SPI_MAX_CS;
+ struct reset_control *reset;

if (dev->of_node) {
const struct of_device_id *match;
@@ -529,6 +531,15 @@ static int bcm63xx_spi_probe(struct platform_device *pdev)
return PTR_ERR(clk);
}

+ reset = devm_reset_control_get_optional_exclusive(dev, NULL);
+ if (IS_ERR(reset)) {
+ ret = PTR_ERR(reset);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev,
+ "failed to get reset controller: %d\n", ret);
+ return ret;
+ }
+
master = spi_alloc_master(dev, sizeof(*bs));
if (!master) {
dev_err(dev, "out of memory\n");
@@ -579,6 +590,12 @@ static int bcm63xx_spi_probe(struct platform_device *pdev)
if (ret)
goto out_err;

+ ret = reset_control_reset(reset);
+ if (ret) {
+ dev_err(dev, "unable to reset device: %d\n", ret);
+ goto out_clk_disable;
+ }
+
bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);

/* register and we are done */
--
2.27.0