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acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver

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This driver adds support for parsing SBSA Generic Watchdog timer
in GTDT, parse all info in SBSA Generic Watchdog Structure in GTDT,
and creating a platform device with that information.

This allows the operating system to obtain device data from the
resource of platform device. The platform device named "sbsa-gwdt"
can be used by the ARM SBSA Generic Watchdog driver.

Signed-off-by: Fu Wei <fu.wei@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
This commit is contained in:
Fu Wei 2017-04-01 01:51:05 +08:00 committed by Mark Rutland
parent c2743a3676
commit ca9ae5ec4e
1 changed files with 103 additions and 0 deletions
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103
drivers/acpi/arm64/gtdt.c
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@ -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);