On Wed, Mar 22, 2017 at 12:31:22AM +0800, fu.wei@linaro.org wrote:
From: Fu Wei fu.wei@linaro.org
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
drivers/acpi/arm64/gtdt.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+)
diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c index f471873..5d167f0 100644 --- a/drivers/acpi/arm64/gtdt.c +++ b/drivers/acpi/arm64/gtdt.c @@ -14,6 +14,7 @@ #include <linux/acpi.h> #include <linux/init.h> #include <linux/kernel.h> +#include <linux/platform_device.h> #include <clocksource/arm_arch_timer.h> @@ -59,6 +60,17 @@ 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; @@ -285,3 +297,85 @@ 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");return -EINVAL;
You should unmap the gsi here.
- }
- 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 (like drivers/watchdog/sbsa_gwdt.c)can get device
Nit: I would not hardcode drivers paths in comments.
* 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) +{
- int ret, i = 0;
- void *platform_timer;
- struct acpi_table_header *table;
- if (acpi_disabled)
return 0;- if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_GTDT, 0, &table)))
return -EINVAL;- ret = acpi_gtdt_init(table, NULL);
- if (ret)
return ret;
Ok, I missed previous versions reviews so I miss the background here and I apologise.
I do not understand why you call acpi_gtdt_init() again (or better, why acpi_gtdt_init() does not return straight away) here if the stashed pointer in acpi_gtdt_desc is already set. I am not a big fan of the for_each_platform_timer macro either, here you can just read the ACPI_SIG_GTDT and parse its entries, I see no point in calling acpi_gtdt_init() again, there is nothing to stash for later probing, is there ?
Or it is just to reuse common parsing code ? Regardless, if the acpi_gtdt_desc struct is already initialized acpi_gtdt_init() should just return or I am missing the point.
I would like clarifications on the acpi_gtdt_init() call above please (plus GSI unmap fix), apart from that:
Reviewed-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com
- for_each_platform_timer(platform_timer) {
if (is_non_secure_watchdog(platform_timer)) {ret = gtdt_import_sbsa_gwdt(platform_timer, i);if (ret)break;i++;}- }
- if (i)
pr_info("found %d SBSA generic Watchdog(s).\n", i);- return ret;
+}
+device_initcall(gtdt_sbsa_gwdt_init);
2.9.3