[PATCH 2/3] irqchip/gic: support RealView variant setup
From: Linus Walleij
Date: Fri Oct 23 2015 - 18:16:21 EST
The ARM RealView PB11MPCore reference design has some special
bits in a system controller register to set up the GIC in one
of three modes: legacy, new with DCC, new without DCC. The
register is also used to enable FIQ.
Since the platform will not boot unless this register is set
up to "new with DCC" mode, we need a special quirk to be
compiled-in for the RealView platforms.
If we find the right compatible string on the GIC TestChip,
we enable this quirk by looking up the system controller and
enabling the special bits.
We depend on the CONFIG_REALVIEW_DT Kconfig symbol as the old
boardfile code has the same fix hardcoded, and this is only
needed for the attempts to modernize the RealView code using
device tree.
After fixing this, the PB11MPCore boots with device tree
only.
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
ChangeLog v1->v2:
- Put the IRQCHIP_DECLARE() in the add-on irq-gic-realview.c file
and have it call down to gic_of_init() after its special
initialization
- Created irq-gic.h to export functions inside irq-gic.c. Part of
me wanted to use irq-gic-common.h so as not to proliferate the
header files, but I felt it was encapsulating the functions in
irq-gic-common.c so it seemed dirty, better to give irq-gic.c
its own header file.
- Broke out this irqchip stuff from the rest of the series so as
not to stress the irqchip maintainers. It has no dependencies
on the other patches anyways, and can be merged stand-alone.
---
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-gic-realview.c | 43 ++++++++++++++++++++++++++++++++++++++
drivers/irqchip/irq-gic.c | 3 ++-
drivers/irqchip/irq-gic.h | 7 +++++++
4 files changed, 53 insertions(+), 1 deletion(-)
create mode 100644 drivers/irqchip/irq-gic-realview.c
create mode 100644 drivers/irqchip/irq-gic.h
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index bb3048f00e64..7a7d4182777d 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_ARCH_SUNXI) += irq-sun4i.o
obj-$(CONFIG_ARCH_SUNXI) += irq-sunxi-nmi.o
obj-$(CONFIG_ARCH_SPEAR3XX) += spear-shirq.o
obj-$(CONFIG_ARM_GIC) += irq-gic.o irq-gic-common.o
+obj-$(CONFIG_REALVIEW_DT) += irq-gic-realview.o
obj-$(CONFIG_ARM_GIC_V2M) += irq-gic-v2m.o
obj-$(CONFIG_ARM_GIC_V3) += irq-gic-v3.o irq-gic-common.o
obj-$(CONFIG_ARM_GIC_V3_ITS) += irq-gic-v3-its.o irq-gic-v3-its-pci-msi.o irq-gic-v3-its-platform-msi.o
diff --git a/drivers/irqchip/irq-gic-realview.c b/drivers/irqchip/irq-gic-realview.c
new file mode 100644
index 000000000000..bb5583c07667
--- /dev/null
+++ b/drivers/irqchip/irq-gic-realview.c
@@ -0,0 +1,43 @@
+/*
+ * Special GIC quirks for the ARM RealView
+ * Copyright (C) 2015 Linus Walleij
+ */
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/bitops.h>
+#include <linux/irqchip.h>
+
+#include "irq-gic.h"
+
+#define REALVIEW_SYS_LOCK_OFFSET 0x20
+#define REALVIEW_PB11MP_SYS_PLD_CTRL1 0x74
+#define VERSATILE_LOCK_VAL 0xA05F
+#define PLD_INTMODE_MASK BIT(22)|BIT(23)|BIT(24)
+#define PLD_INTMODE_LEGACY 0x0
+#define PLD_INTMODE_NEW_DCC BIT(22)
+#define PLD_INTMODE_NEW_NO_DCC BIT(23)
+#define PLD_INTMODE_FIQ_ENABLE BIT(24)
+
+static int __init
+realview_gic_of_init(struct device_node *node, struct device_node *parent)
+{
+ static struct regmap *map;
+
+ /* The PB11MPCore GIC needs to be configured in the syscon */
+ map = syscon_regmap_lookup_by_compatible("arm,realview-pb11mp-syscon");
+ if (!IS_ERR(map)) {
+ /* new irq mode with no DCC */
+ regmap_write(map, REALVIEW_SYS_LOCK_OFFSET,
+ VERSATILE_LOCK_VAL);
+ regmap_update_bits(map, REALVIEW_PB11MP_SYS_PLD_CTRL1,
+ PLD_INTMODE_NEW_NO_DCC,
+ PLD_INTMODE_MASK);
+ regmap_write(map, REALVIEW_SYS_LOCK_OFFSET, 0x0000);
+ pr_info("TC11MP GIC: set up interrupt controller to NEW mode, no DCC\n");
+ } else {
+ pr_err("TC11MP GIC setup: could not find syscon\n");
+ }
+ return gic_of_init(node, parent);
+}
+IRQCHIP_DECLARE(armtc11mp_gic, "arm,tc11mp-gic", realview_gic_of_init);
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 982c09c2d791..9ec8cf5137d9 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -50,6 +50,7 @@
#include <asm/virt.h>
#include "irq-gic-common.h"
+#include "irq-gic.h"
union gic_base {
void __iomem *common_base;
@@ -1141,7 +1142,7 @@ static bool gic_check_eoimode(struct device_node *node, void __iomem **base)
return true;
}
-static int __init
+int __init
gic_of_init(struct device_node *node, struct device_node *parent)
{
void __iomem *cpu_base;
diff --git a/drivers/irqchip/irq-gic.h b/drivers/irqchip/irq-gic.h
new file mode 100644
index 000000000000..3c45a540c235
--- /dev/null
+++ b/drivers/irqchip/irq-gic.h
@@ -0,0 +1,7 @@
+#include <linux/of.h>
+
+/*
+ * Subdrivers that need some preparatory work can initialize their
+ * chips and call this to register their GICs.
+ */
+int gic_of_init(struct device_node *node, struct device_node *parent);
--
2.4.3
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/