[PATCH 7/8] efi: clocksoure: use event for timer

[Jean-Christophe PLAGNIOL-VILLARD]

with this we can be hw generic

If the EFI implement timestamp protocol we could use instead of event
but even EDK2 Never Ever compile it for any target.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com>
---
 common/efi/efi.c             |   8 ++++
 drivers/clocksource/Kconfig  |   4 ++
 drivers/clocksource/Makefile |   1 +
 drivers/clocksource/efi.c    | 110 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 123 insertions(+)
 create mode 100644 drivers/clocksource/efi.c

diff --git a/common/efi/efi.c b/common/efi/efi.c
index 4b589b600..05c58250f 100644
--- a/common/efi/efi.c
+++ b/common/efi/efi.c
@@ -353,6 +353,14 @@ efi_status_t efi_main(efi_handle_t image, efi_system_table_t *sys_table)
 	return EFI_SUCCESS;
 }
 
+static int efi_core_init(void)
+{
+	struct device_d *dev = device_alloc("efi-cs", DEVICE_ID_SINGLE);
+
+	return platform_device_register(dev);
+}
+core_initcall(efi_core_init);
+
 static int efi_postcore_init(void)
 {
 	char *uuid;
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 9b7f0a9d7..b12a85403 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -34,6 +34,10 @@ config CLOCKSOURCE_DUMMY_RATE
 	  The option CONFIG_CLOCKSOURCE_DUMMY_RATE is used to adjust this clocksource.
 	  The bigger rate valuest makes clocksource "faster".
 
+config CLOCKSOURCE_EFI
+	bool "Generic EFI Driver"
+	depends on EFI_BOOTUP
+
 config CLOCKSOURCE_EFI_X86
 	bool "EFI X86 HW driver"
 	depends on EFI_BOOTUP && X86
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 1fd18296e..f69b33d0b 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -3,6 +3,7 @@ obj-$(CONFIG_ARM_SMP_TWD) += arm_smp_twd.o
 obj-$(CONFIG_CLOCKSOURCE_BCM283X) += bcm2835.o
 obj-$(CONFIG_CLOCKSOURCE_CLPS711X) += clps711x.o
 obj-$(CONFIG_CLOCKSOURCE_DIGIC)   += digic.o
+obj-$(CONFIG_CLOCKSOURCE_EFI) += efi.o
 obj-$(CONFIG_CLOCKSOURCE_EFI_X86) += efi_x86.o
 obj-$(CONFIG_CLOCKSOURCE_MVEBU)   += mvebu.o
 obj-$(CONFIG_CLOCKSOURCE_NOMADIK) += nomadik.o
diff --git a/drivers/clocksource/efi.c b/drivers/clocksource/efi.c
new file mode 100644
index 000000000..df65dd86c
--- /dev/null
+++ b/drivers/clocksource/efi.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnio at jcrosoft.com>
+ *
+ * Under GPL v2
+ */
+#include <common.h>
+#include <init.h>
+#include <driver.h>
+#include <clock.h>
+#include <efi.h>
+#include <efi/efi.h>
+#include <efi/efi-device.h>
+#include <linux/err.h>
+
+static uint64_t ticks = 1;
+static void *efi_cs_evt;
+
+static uint64_t efi_cs_read(void)
+{
+	return ticks;
+}
+
+static void efi_cs_inc(void *event, void *ctx)
+{
+	ticks++;
+}
+
+/* count ticks during a 1dms */
+static uint64_t ticks_freq(void)
+{
+	uint64_t ticks_start, ticks_end;
+
+	ticks_start = ticks;
+	BS->stall(1000);
+	ticks_end = ticks;
+
+	return (ticks_end - ticks_start) * 1000;
+}
+
+/* count ticks during a 20ms delay as on qemu x86_64 the max is 100Hz */
+static uint64_t ticks_freq_x86(void)
+{
+	uint64_t ticks_start, ticks_end;
+
+	ticks_start = ticks;
+	BS->stall(20 * 1000);
+	ticks_end = ticks;
+
+	return (ticks_end - ticks_start) * 50;
+}
+
+static int efi_cs_init(struct clocksource *cs)
+{
+	efi_status_t efiret;
+	uint64_t freq;
+
+	efiret = BS->create_event(EFI_EVT_TIMER | EFI_EVT_NOTIFY_SIGNAL,
+			EFI_TPL_CALLBACK, efi_cs_inc, NULL, &efi_cs_evt);
+
+	if (EFI_ERROR(efiret))
+		return -efi_errno(efiret);
+
+	efiret = BS->set_timer(efi_cs_evt, EFI_TIMER_PERIODIC, 10);
+	if (EFI_ERROR(efiret)) {
+		BS->close_event(efi_cs_evt);
+		return -efi_errno(efiret);
+	}
+
+	freq = 1000 * 1000;
+	if (ticks_freq() < 800 * 1000) {
+		uint64_t nb_100ns;
+
+		freq = ticks_freq_x86();
+		nb_100ns = 10 * 1000 * 1000 / freq;
+		pr_warn("EFI Event timer too slow freq = %llu Hz\n", freq);
+		efiret = BS->set_timer(efi_cs_evt, EFI_TIMER_PERIODIC, nb_100ns);
+		if (EFI_ERROR(efiret)) {
+			BS->close_event(efi_cs_evt);
+			return -efi_errno(efiret);
+		}
+	}
+
+	cs->mult = clocksource_hz2mult(freq, cs->shift);
+
+	return 0;
+}
+
+static struct clocksource efi_cs = {
+	.read   = efi_cs_read,
+	.mask   = CLOCKSOURCE_MASK(64),
+	.shift  = 0,
+	.init   = efi_cs_init,
+};
+
+static int efi_cs_probe(struct device_d *dev)
+{
+	return init_clock(&efi_cs);
+}
+
+static struct driver_d efi_cs_driver = {
+	.name = "efi-cs",
+	.probe = efi_cs_probe,
+};
+
+static int efi_cs_initcall(void)
+{
+	return platform_driver_register(&efi_cs_driver);
+}
+/* for efi the time must be init at core initcall level */
+late_initcall(efi_cs_initcall);
-- 
2.11.0