soc/tegra: fuse: Add tegra_acpi_init_apbmisc()

In preparation to ACPI support in Tegra fuse driver add function
tegra_acpi_init_apbmisc() to initialize tegra-apbmisc driver.
Also, document the reason of calling tegra_init_apbmisc() at early init.

Note that function tegra_acpi_init_apbmisc() is not placed in the __init
section, because it will be called during probe.

Signed-off-by: Kartik <kkartik@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/soc/tegra/fuse/fuse.h b/drivers/soc/tegra/fuse/fuse.h
index 90f23be738947a5b5ebd7e8dc03e01bdd5d6b434..a41e9f85281aa87843f75ba63d54c97fc4d958db 100644 (file)
--- a/drivers/soc/tegra/fuse/fuse.h
+++ b/drivers/soc/tegra/fuse/fuse.h
@@ -69,6 +69,7 @@ struct tegra_fuse {
 
 void tegra_init_revision(void);
 void tegra_init_apbmisc(void);
+void tegra_acpi_init_apbmisc(void);
 
 u32 __init tegra_fuse_read_spare(unsigned int spare);
 u32 __init tegra_fuse_read_early(unsigned int offset);

diff --git a/drivers/soc/tegra/fuse/tegra-apbmisc.c b/drivers/soc/tegra/fuse/tegra-apbmisc.c
index 06c1b3a2c7eccc39992ae1ace4c96f9e50996422..6457f80821bb9582c9b8b6a75add2aede4e16254 100644 (file)
--- a/drivers/soc/tegra/fuse/tegra-apbmisc.c
+++ b/drivers/soc/tegra/fuse/tegra-apbmisc.c
@@ -3,9 +3,11 @@
  * Copyright (c) 2014-2023, NVIDIA CORPORATION.  All rights reserved.
  */
 
+#include <linux/acpi.h>
 #include <linux/export.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 
@@ -180,6 +182,12 @@ static void tegra_init_apbmisc_resources(struct resource *apbmisc,
        }
 }
 
+/**
+ * tegra_init_apbmisc - Initializes Tegra APBMISC and Strapping registers.
+ *
+ * This is called during early init as some of the old 32-bit ARM code needs
+ * information from the APBMISC registers very early during boot.
+ */
 void __init tegra_init_apbmisc(void)
 {
        struct resource apbmisc, straps;
@@ -244,3 +252,67 @@ void __init tegra_init_apbmisc(void)
 put:
        of_node_put(np);
 }
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id apbmisc_acpi_match[] = {
+       { "NVDA2010" },
+       { /* sentinel */ }
+};
+
+void tegra_acpi_init_apbmisc(void)
+{
+       struct resource *resources[2] = { NULL };
+       struct resource_entry *rentry;
+       struct acpi_device *adev = NULL;
+       struct list_head resource_list;
+       int rcount = 0;
+       int ret;
+
+       adev = acpi_dev_get_first_match_dev(apbmisc_acpi_match[0].id, NULL, -1);
+       if (!adev)
+               return;
+
+       INIT_LIST_HEAD(&resource_list);
+
+       ret = acpi_dev_get_memory_resources(adev, &resource_list);
+       if (ret < 0) {
+               pr_err("failed to get APBMISC memory resources");
+               goto out_put_acpi_dev;
+       }
+
+       /*
+        * Get required memory resources.
+        *
+        * resources[0]: apbmisc.
+        * resources[1]: straps.
+        */
+       resource_list_for_each_entry(rentry, &resource_list) {
+               if (rcount >= ARRAY_SIZE(resources))
+                       break;
+
+               resources[rcount++] = rentry->res;
+       }
+
+       if (!resources[0]) {
+               pr_err("failed to get APBMISC registers\n");
+               goto out_free_resource_list;
+       }
+
+       if (!resources[1]) {
+               pr_err("failed to get strapping options registers\n");
+               goto out_free_resource_list;
+       }
+
+       tegra_init_apbmisc_resources(resources[0], resources[1]);
+
+out_free_resource_list:
+       acpi_dev_free_resource_list(&resource_list);
+
+out_put_acpi_dev:
+       acpi_dev_put(adev);
+}
+#else
+void tegra_acpi_init_apbmisc(void)
+{
+}
+#endif