soc/tegra: pmc: Restrict legacy code to 32-bit ARM

For backwards-compatibility with old device trees, if no PMC node exists
this driver hard-codes the I/O memory region. All 64-bit ARM device tree
files are recent enough that they can be required to have this node, and
therefore the legacy code path is not required on 64-bit ARM.

Based on work done by Paul Walmsley <pwalmsley@nvidia.com>.

Cc: Paul Walmsley <pwalmsley@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 fa7036c4daf9c929cbd4d47f63590334c115457e..84da174bedece258375b24076ffff2216d9088bc 100644 (file)
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -17,6 +17,8 @@
  *
  */
 
+#define pr_fmt(fmt) "tegra-pmc: " fmt
+
 #include <linux/kernel.h>
 #include <linux/clk.h>
 #include <linux/clk/tegra.h>
@@ -1003,6 +1005,7 @@ static const struct tegra_pmc_soc tegra124_pmc_soc = {
 };
 
 static const struct of_device_id tegra_pmc_match[] = {
+       { .compatible = "nvidia,tegra132-pmc", .data = &tegra124_pmc_soc },
        { .compatible = "nvidia,tegra124-pmc", .data = &tegra124_pmc_soc },
        { .compatible = "nvidia,tegra114-pmc", .data = &tegra114_pmc_soc },
        { .compatible = "nvidia,tegra30-pmc", .data = &tegra30_pmc_soc },
@@ -1035,25 +1038,44 @@ static int __init tegra_pmc_early_init(void)
        bool invert;
        u32 value;
 
-       if (!soc_is_tegra())
-               return 0;
-
        np = of_find_matching_node_and_match(NULL, tegra_pmc_match, &match);
        if (!np) {
-               pr_warn("PMC device node not found, disabling powergating\n");
-
-               regs.start = 0x7000e400;
-               regs.end = 0x7000e7ff;
-               regs.flags = IORESOURCE_MEM;
-
-               pr_warn("Using memory region %pR\n", &regs);
+               /*
+                * Fall back to legacy initialization for 32-bit ARM only. All
+                * 64-bit ARM device tree files for Tegra are required to have
+                * a PMC node.
+                *
+                * This is for backwards-compatibility with old device trees
+                * that didn't contain a PMC node. Note that in this case the
+                * SoC data can't be matched and therefore powergating is
+                * disabled.
+                */
+               if (IS_ENABLED(CONFIG_ARM) && soc_is_tegra()) {
+                       pr_warn("DT node not found, powergating disabled\n");
+
+                       regs.start = 0x7000e400;
+                       regs.end = 0x7000e7ff;
+                       regs.flags = IORESOURCE_MEM;
+
+                       pr_warn("Using memory region %pR\n", &regs);
+               } else {
+                       /*
+                        * At this point we're not running on Tegra, so play
+                        * nice with multi-platform kernels.
+                        */
+                       return 0;
+               }
        } else {
-               pmc->soc = match->data;
-       }
+               /*
+                * Extract information from the device tree if we've found a
+                * matching node.
+                */
+               if (of_address_to_resource(np, 0, &regs) < 0) {
+                       pr_err("failed to get PMC registers\n");
+                       return -ENXIO;
+               }
 
-       if (of_address_to_resource(np, 0, &regs) < 0) {
-               pr_err("failed to get PMC registers\n");
-               return -ENXIO;
+               pmc->soc = match->data;
        }
 
        pmc->base = ioremap_nocache(regs.start, resource_size(&regs));
@@ -1064,6 +1086,10 @@ static int __init tegra_pmc_early_init(void)
 
        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");
 
        value = tegra_pmc_readl(PMC_CNTRL);