[PATCH v4 4/8] soc/tegra: fuse: Add tegra_acpi_init_apbmisc()

From: Kartik
Date: Wed Oct 11 2023 - 07:17:41 EST


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@xxxxxxxxxx>
---
v2 -> v3:
* Fix build warnings seen when CONFIG_ACPI is disabled by moving
tegra_init_apbmisc table inside #ifdef CONFIG_ACPI block.

v1 -> v2:
* Update ACPI ID table 'tegra_init_apbmisc'.
* Add comment to document the reason to call tegra_init_apbmisc
at early init.
* Fix an issue where acpi_dev_free_resource_list() and
* acpi_dev_put() were not called if
acpi_dev_get_memory_resources() returned 1.
* Update logic to fetch memory resources in
tegra_acpi_init_apbmisc().
* Fix build errors seen when CONFIG_ACPI is disabled.
---
drivers/soc/tegra/fuse/fuse.h | 1 +
drivers/soc/tegra/fuse/tegra-apbmisc.c | 72 ++++++++++++++++++++++++++
2 files changed, 73 insertions(+)

diff --git a/drivers/soc/tegra/fuse/fuse.h b/drivers/soc/tegra/fuse/fuse.h
index 90f23be73894..a41e9f85281a 100644
--- 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 06c1b3a2c7ec..e2ca93de6c1f 100644
--- 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, *tmp;
+ 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_safe(rentry, tmp, &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
--
2.34.1