soc/tegra: pmc: Fix early initialisation of PMC

During early initialisation, the available power partitions for a given
device is configured as well as the polarity of the PMC interrupt. Both
of which should only be configured if there is a valid device node for
the PMC device. This is because the soc data used for configuring the
power partitions is only available if a device node for the PMC is found
and the code to configure the interrupt polarity uses the device node
pointer directly.

Some early device-tree images may not have this device node and so fix
this by ensuring the device node pointer is valid when configuring these
items.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index 52a9e97..2e031c4 100644 (file)
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -1550,27 +1550,29 @@ static int __init tegra_pmc_early_init(void)
                return -ENXIO;
        }
 
-       /* Create a bit-map of the available and valid partitions */
-       for (i = 0; i < pmc->soc->num_powergates; i++)
-               if (pmc->soc->powergates[i])
-                       set_bit(i, pmc->powergates_available);
-
        mutex_init(&pmc->powergates_lock);
 
-       /*
-        * Invert the interrupt polarity if a PMC device tree node exists and
-        * contains the nvidia,invert-interrupt property.
-        */
-       invert = of_property_read_bool(np, "nvidia,invert-interrupt");
+       if (np) {
+               /* Create a bit-map of the available and valid partitions */
+               for (i = 0; i < pmc->soc->num_powergates; i++)
+                       if (pmc->soc->powergates[i])
+                               set_bit(i, pmc->powergates_available);
 
-       value = tegra_pmc_readl(PMC_CNTRL);
+               /*
+                * Invert the interrupt polarity if a PMC device tree node
+                * exists and contains the nvidia,invert-interrupt property.
+                */
+               invert = of_property_read_bool(np, "nvidia,invert-interrupt");
 
-       if (invert)
-               value |= PMC_CNTRL_INTR_POLARITY;
-       else
-               value &= ~PMC_CNTRL_INTR_POLARITY;
+               value = tegra_pmc_readl(PMC_CNTRL);
 
-       tegra_pmc_writel(value, PMC_CNTRL);
+               if (invert)
+                       value |= PMC_CNTRL_INTR_POLARITY;
+               else
+                       value &= ~PMC_CNTRL_INTR_POLARITY;
+
+               tegra_pmc_writel(value, PMC_CNTRL);
+       }
 
        return 0;
 }