acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver (ca9ae5ec) · Commits · 戴 / test

drivers/acpi/arm64/gtdt.c

+103 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		#include <linux/init.h>
		#include <linux/irqdomain.h>
		#include <linux/kernel.h>
		#include <linux/platform_device.h>

		#include <clocksource/arm_arch_timer.h>

		@@ -60,6 +61,17 @@ static inline bool is_timer_block(void *platform_timer)
		return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK;
		}

		static inline bool is_non_secure_watchdog(void *platform_timer)
		{
		struct acpi_gtdt_header *gh = platform_timer;
		struct acpi_gtdt_watchdog *wd = platform_timer;

		if (gh->type != ACPI_GTDT_TYPE_WATCHDOG)
		return false;

		return !(wd->timer_flags & ACPI_GTDT_WATCHDOG_SECURE);
		}

		static int __init map_gt_gsi(u32 interrupt, u32 flags)
		{
		int trigger, polarity;
		@@ -312,3 +324,94 @@ int __init acpi_arch_timer_mem_init(struct arch_timer_mem *timer_mem,

		return 0;
		}

		/*
		* Initialize a SBSA generic Watchdog platform device info from GTDT
		*/
		static int __init gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
		int index)
		{
		struct platform_device *pdev;
		int irq = map_gt_gsi(wd->timer_interrupt, wd->timer_flags);

		/*
		* According to SBSA specification the size of refresh and control
		* frames of SBSA Generic Watchdog is SZ_4K(Offset 0x000 – 0xFFF).
		*/
		struct resource res[] = {
		DEFINE_RES_MEM(wd->control_frame_address, SZ_4K),
		DEFINE_RES_MEM(wd->refresh_frame_address, SZ_4K),
		DEFINE_RES_IRQ(irq),
		};
		int nr_res = ARRAY_SIZE(res);

		pr_debug("found a Watchdog (0x%llx/0x%llx gsi:%u flags:0x%x).\n",
		wd->refresh_frame_address, wd->control_frame_address,
		wd->timer_interrupt, wd->timer_flags);

		if (!(wd->refresh_frame_address && wd->control_frame_address)) {
		pr_err(FW_BUG "failed to get the Watchdog base address.\n");
		acpi_unregister_gsi(wd->timer_interrupt);
		return -EINVAL;
		}

		if (irq <= 0) {
		pr_warn("failed to map the Watchdog interrupt.\n");
		nr_res--;
		}

		/*
		* Add a platform device named "sbsa-gwdt" to match the platform driver.
		* "sbsa-gwdt": SBSA(Server Base System Architecture) Generic Watchdog
		* The platform driver can get device info below by matching this name.
		*/
		pdev = platform_device_register_simple("sbsa-gwdt", index, res, nr_res);
		if (IS_ERR(pdev)) {
		acpi_unregister_gsi(wd->timer_interrupt);
		return PTR_ERR(pdev);
		}

		return 0;
		}

		static int __init gtdt_sbsa_gwdt_init(void)
		{
		void *platform_timer;
		struct acpi_table_header *table;
		int ret, timer_count, gwdt_count = 0;

		if (acpi_disabled)
		return 0;

		if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_GTDT, 0, &table)))
		return -EINVAL;

		/*
		* Note: Even though the global variable acpi_gtdt_desc has been
		* initialized by acpi_gtdt_init() while initializing the arch timers,
		* when we call this function to get SBSA watchdogs info from GTDT, the
		* pointers stashed in it are stale (since they are early temporary
		* mappings carried out before acpi_permanent_mmap is set) and we need
		* to re-initialize them with permanent mapped pointer values to let the
		* GTDT parsing possible.
		*/
		ret = acpi_gtdt_init(table, &timer_count);
		if (ret \|\| !timer_count)
		return ret;

		for_each_platform_timer(platform_timer) {
		if (is_non_secure_watchdog(platform_timer)) {
		ret = gtdt_import_sbsa_gwdt(platform_timer, gwdt_count);
		if (ret)
		break;
		gwdt_count++;
		}
		}

		if (gwdt_count)
		pr_info("found %d SBSA generic Watchdog(s).\n", gwdt_count);

		return ret;
		}

		device_initcall(gtdt_sbsa_gwdt_init);

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