[PATCH v23 11/11] acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver

[fu . wei]

From: Fu Wei 

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 
Signed-off-by: Hanjun Guo 
Tested-by: Xiongfeng Wang 
Reviewed-by: Lorenzo Pieralisi 
---
 drivers/acpi/arm64/gtdt.c | 103 ++
 1 file changed, 103 insertions(+)

diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c
index 3dd33f3..d73bb16 100644
--- a/drivers/acpi/arm64/gtdt.c
+++ b/drivers/acpi/arm64/gtdt.c
@@ -15,6 +15,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include 
 
@@ -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;
@@ -301,3 +313,94 @@ 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, )))
+   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, _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);
-- 
2.9.3

[PATCH v23 11/11] acpi/arm64: Add SBSA Generic Watchdog support in GTDT driver

[fu . wei]

From: Fu Wei 

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 
Signed-off-by: Hanjun Guo 
Tested-by: Xiongfeng Wang 
Reviewed-by: Lorenzo Pieralisi 
---
 drivers/acpi/arm64/gtdt.c | 103 ++
 1 file changed, 103 insertions(+)

diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c
index 3dd33f3..d73bb16 100644
--- a/drivers/acpi/arm64/gtdt.c
+++ b/drivers/acpi/arm64/gtdt.c
@@ -15,6 +15,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include 
 
@@ -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;
@@ -301,3 +313,94 @@ 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, )))
+   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, _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);
-- 
2.9.3