[PATCH v3 3/4] spi: bcm63xx-hsspi: add reset support

Álvaro Fernández Rojas
2020-06-16T07:02:38Z

bcm63xx arch resets the HSSPI 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-hsspi.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/spi/spi-bcm63xx-hsspi.c b/drivers/spi/spi-bcm63xx-hsspi.c
index 6c235306c0e4..45e2b0942e64 100644
--- a/drivers/spi/spi-bcm63xx-hsspi.c
+++ b/drivers/spi/spi-bcm63xx-hsspi.c
@@ -20,6 +20,7 @@
#include <linux/spi/spi.h>
#include <linux/mutex.h>
#include <linux/of.h>
+#include <linux/reset.h>

#define HSSPI_GLOBAL_CTRL_REG 0x0
#define GLOBAL_CTRL_CS_POLARITY_SHIFT 0
@@ -334,6 +335,7 @@ static int bcm63xx_hsspi_probe(struct platform_device *pdev)
struct clk *clk, *pll_clk = NULL;
int irq, ret;
u32 reg, rate, num_cs = HSSPI_SPI_MAX_CS;
+ struct reset_control *reset;

irq = platform_get_irq(pdev, 0);
if (irq < 0)
@@ -348,10 +350,25 @@ static int bcm63xx_hsspi_probe(struct platform_device *pdev)
if (IS_ERR(clk))
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;
+ }
+
ret = clk_prepare_enable(clk);
if (ret)
return ret;

+ ret = reset_control_reset(reset);
+ if (ret) {
+ dev_err(dev, "unable to reset device: %d\n", ret);
+ goto out_disable_clk;
+ }
+
rate = clk_get_rate(clk);
if (!rate) {
pll_clk = devm_clk_get(dev, "pll");
--
2.27.0