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

[Álvaro Fernández Rojas]

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 <nolt...@gmail.com>
Reviewed-by: Philipp Zabel <p.za...@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