spi: bcm63xx-hsspi: add reset support

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>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20200616173235.3473149-3-noltari@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-bcm63xx-hsspi.c b/drivers/spi/spi-bcm63xx-hsspi.c
index 6c23530..9909b18 100644 (file)
--- 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 +350,20 @@ 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))
+               return PTR_ERR(reset);
+
        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");