spi: stm32-qspi: defer probe for reset controller

Changes stm32 QSPI driver to defer its probe operation when a reset
controller device have not yet probed but is registered in the
system.

Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Link: https://lore.kernel.org/r/20200203135048.1299-2-patrice.chotard@st.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-stm32-qspi.c b/drivers/spi/spi-stm32-qspi.c
index 4ef569b..13bb64b 100644 (file)
--- a/drivers/spi/spi-stm32-qspi.c
+++ b/drivers/spi/spi-stm32-qspi.c
@@ -615,7 +615,11 @@ static int stm32_qspi_probe(struct platform_device *pdev)
        }
 
        rstc = devm_reset_control_get_exclusive(dev, NULL);
-       if (!IS_ERR(rstc)) {
+       if (IS_ERR(rstc)) {
+               ret = PTR_ERR(rstc);
+               if (ret == -EPROBE_DEFER)
+                       goto err;
+       } else {
                reset_control_assert(rstc);
                udelay(2);
                reset_control_deassert(rstc);