The Aspeed SOCs provide some interrupts through the System Control
Unit registers. Add an interrupt controller that provides these
interrupts to the system. Add the interrupt controller to the AST25XX
and AST26XX devicetrees.
Changes since v1:
- add a spinlock to protect read-modify-write operation for irq masking
- use readl/writel relaxed versions
- add a comment explaining the irq status/enable register
- provide affinity callback that returns -EINVAL
Eddie James (4):
dt-bindings: interrupt-controller: Add Aspeed SCU interrupt controller
irqchip: Add Aspeed SCU interrupt controller
ARM: dts: aspeed: ast2500: Add SCU interrupt controller
ARM: dts: aspeed: ast2600: Add SCU interrupt controllers
.../interrupt-controller/aspeed,ast2xxx-scu-ic.txt | 26 +++
MAINTAINERS | 8 +
arch/arm/boot/dts/aspeed-g5.dtsi | 11 +-
arch/arm/boot/dts/aspeed-g6.dtsi | 18 ++
drivers/irqchip/Makefile | 2 +-
drivers/irqchip/irq-aspeed-scu-ic.c | 233 +++++++++++++++++++++
.../interrupt-controller/aspeed-scu-ic.h | 23 ++
7 files changed, 319 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt
create mode 100644 drivers/irqchip/irq-aspeed-scu-ic.c
create mode 100644 include/dt-bindings/interrupt-controller/aspeed-scu-ic.h
--
1.8.3.1
The Aspeed SOCs provide some interrupts through the System Control
Unit registers. Add an interrupt controller that provides these
interrupts to the system.
Signed-off-by: Eddie James <[email protected]>
---
Changes since v1:
- add a spinlock to protect read-modify-write operation for irq masking
- use readl/writel relaxed versions
- add a comment explaining the irq status/enable register
- provide affinity callback that returns -EINVAL
MAINTAINERS | 1 +
drivers/irqchip/Makefile | 2 +-
drivers/irqchip/irq-aspeed-scu-ic.c | 233 ++++++++++++++++++++++++++++++++++++
3 files changed, 235 insertions(+), 1 deletion(-)
create mode 100644 drivers/irqchip/irq-aspeed-scu-ic.c
diff --git a/MAINTAINERS b/MAINTAINERS
index c7e028c..b6db122 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2656,6 +2656,7 @@ M: Eddie James <[email protected]>
L: [email protected] (moderated for non-subscribers)
S: Maintained
F: Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt
+F: drivers/irqchip/irq-aspeed-scu-ic.c
F: include/dt-bindings/interrupt-controller/aspeed-scu-ic.h
ASPEED VIDEO ENGINE DRIVER
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index cc7c439..fce6b1d 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -86,7 +86,7 @@ obj-$(CONFIG_MVEBU_PIC) += irq-mvebu-pic.o
obj-$(CONFIG_MVEBU_SEI) += irq-mvebu-sei.o
obj-$(CONFIG_LS_SCFG_MSI) += irq-ls-scfg-msi.o
obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o
-obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o irq-aspeed-i2c-ic.o
+obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o irq-aspeed-i2c-ic.o irq-aspeed-scu-ic.o
obj-$(CONFIG_STM32_EXTI) += irq-stm32-exti.o
obj-$(CONFIG_QCOM_IRQ_COMBINER) += qcom-irq-combiner.o
obj-$(CONFIG_IRQ_UNIPHIER_AIDET) += irq-uniphier-aidet.o
diff --git a/drivers/irqchip/irq-aspeed-scu-ic.c b/drivers/irqchip/irq-aspeed-scu-ic.c
new file mode 100644
index 0000000..64c3ac4
--- /dev/null
+++ b/drivers/irqchip/irq-aspeed-scu-ic.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Aspeed AST24XX, AST25XX, and AST26XX SCU Interrupt Controller
+ * Copyright 2019 IBM Corporation
+ *
+ * Eddie James <[email protected]>
+ */
+
+#include <linux/bitops.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+
+#define ASPEED_SCU_IC_SHIFT 0
+#define ASPEED_SCU_IC_ENABLE GENMASK(6, ASPEED_SCU_IC_SHIFT)
+#define ASPEED_SCU_IC_NUM_IRQS 7
+#define ASPEED_SCU_IC_STATUS_SHIFT 16
+
+#define ASPEED_AST2600_SCU_IC0_SHIFT 0
+#define ASPEED_AST2600_SCU_IC0_ENABLE \
+ GENMASK(5, ASPEED_AST2600_SCU_IC0_SHIFT)
+#define ASPEED_AST2600_SCU_IC0_NUM_IRQS 6
+
+#define ASPEED_AST2600_SCU_IC1_SHIFT 4
+#define ASPEED_AST2600_SCU_IC1_ENABLE \
+ GENMASK(5, ASPEED_AST2600_SCU_IC1_SHIFT)
+#define ASPEED_AST2600_SCU_IC1_NUM_IRQS 2
+
+struct aspeed_scu_ic {
+ unsigned long irq_enable;
+ unsigned long irq_shift;
+ unsigned int num_irqs;
+ void __iomem *reg;
+ struct irq_domain *irq_domain;
+ spinlock_t lock;
+};
+
+static void aspeed_scu_ic_irq_handler(struct irq_desc *desc)
+{
+ unsigned int irq;
+ unsigned long bit;
+ unsigned long enabled;
+ unsigned long max;
+ unsigned long status;
+ struct aspeed_scu_ic *scu_ic = irq_desc_get_handler_data(desc);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+
+ chained_irq_enter(chip, desc);
+
+ /*
+ * The SCU IC has just one register to control its operation and read
+ * status. The interrupt enable bits occupy the lower 16 bits of the
+ * register, while the interrupt status bits occupy the upper 16 bits.
+ * The status bit for a given interrupt is always 16 bits shifted from
+ * the enable bit for the same interrupt.
+ * Therefore, perform the IRQ operations in the enable bit space by
+ * shifting the status down to get the mapping and then back up to
+ * clear the bit.
+ */
+ status = readl_relaxed(scu_ic->reg);
+ enabled = status & scu_ic->irq_enable;
+ status = (status >> ASPEED_SCU_IC_STATUS_SHIFT) & enabled;
+
+ bit = scu_ic->irq_shift;
+ max = scu_ic->num_irqs + bit;
+
+ for_each_set_bit_from(bit, &status, max) {
+ irq = irq_find_mapping(scu_ic->irq_domain,
+ bit - scu_ic->irq_shift);
+ generic_handle_irq(irq);
+
+ writel_relaxed(enabled | BIT(bit + ASPEED_SCU_IC_STATUS_SHIFT),
+ scu_ic->reg);
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+static void aspeed_scu_ic_irq_mask(struct irq_data *data)
+{
+ struct aspeed_scu_ic *scu_ic = irq_data_get_irq_chip_data(data);
+ unsigned long bit = BIT(data->hwirq + scu_ic->irq_shift);
+ unsigned long flags;
+ unsigned long reg;
+
+ spin_lock_irqsave(&scu_ic->lock, flags);
+
+ reg = readl_relaxed(scu_ic->reg);
+ writel_relaxed((reg & ~bit) & scu_ic->irq_enable, scu_ic->reg);
+
+ spin_unlock_irqrestore(&scu_ic->lock, flags);
+}
+
+static void aspeed_scu_ic_irq_unmask(struct irq_data *data)
+{
+ struct aspeed_scu_ic *scu_ic = irq_data_get_irq_chip_data(data);
+ unsigned long bit = BIT(data->hwirq + scu_ic->irq_shift);
+ unsigned long flags;
+ unsigned long reg;
+
+ spin_lock_irqsave(&scu_ic->lock, flags);
+
+ reg = readl_relaxed(scu_ic->reg);
+ writel_relaxed((reg | bit) & scu_ic->irq_enable, scu_ic->reg);
+
+ spin_unlock_irqrestore(&scu_ic->lock, flags);
+}
+
+static int aspeed_scu_ic_irq_set_affinity(struct irq_data *data,
+ const struct cpumask *dest,
+ bool force)
+{
+ return -EINVAL;
+}
+
+struct irq_chip aspeed_scu_ic_chip = {
+ .name = "aspeed-scu-ic",
+ .irq_mask = aspeed_scu_ic_irq_mask,
+ .irq_unmask = aspeed_scu_ic_irq_unmask,
+ .irq_set_affinity = aspeed_scu_ic_irq_set_affinity,
+};
+
+static int aspeed_scu_ic_map(struct irq_domain *domain, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ irq_set_chip_and_handler(irq, &aspeed_scu_ic_chip, handle_simple_irq);
+ irq_set_chip_data(irq, domain->host_data);
+
+ return 0;
+}
+
+static const struct irq_domain_ops aspeed_scu_ic_domain_ops = {
+ .map = aspeed_scu_ic_map,
+};
+
+static int aspeed_scu_ic_of_init_common(struct aspeed_scu_ic *scu_ic,
+ struct device_node *node)
+{
+ int irq;
+ int rc = 0;
+
+ scu_ic->reg = of_iomap(node, 0);
+ if (!scu_ic->reg) {
+ rc = -ENOMEM;
+ goto err_free;
+ }
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq < 0) {
+ rc = irq;
+ goto err_iounmap;
+ }
+
+ spin_lock_init(&scu_ic->lock);
+
+ scu_ic->irq_domain = irq_domain_add_linear(node, scu_ic->num_irqs,
+ &aspeed_scu_ic_domain_ops,
+ scu_ic);
+ if (!scu_ic->irq_domain) {
+ rc = -ENOMEM;
+ goto err_iounmap;
+ }
+
+ irq_set_chained_handler_and_data(irq, aspeed_scu_ic_irq_handler,
+ scu_ic);
+
+ return 0;
+
+err_iounmap:
+ iounmap(scu_ic->reg);
+
+err_free:
+ kfree(scu_ic);
+
+ return rc;
+}
+
+static int __init aspeed_scu_ic_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct aspeed_scu_ic *scu_ic = kzalloc(sizeof(*scu_ic), GFP_KERNEL);
+
+ if (!scu_ic)
+ return -ENOMEM;
+
+ scu_ic->irq_enable = ASPEED_SCU_IC_ENABLE;
+ scu_ic->irq_shift = ASPEED_SCU_IC_SHIFT;
+ scu_ic->num_irqs = ASPEED_SCU_IC_NUM_IRQS;
+
+ return aspeed_scu_ic_of_init_common(scu_ic, node);
+}
+
+static int __init aspeed_ast2600_scu_ic0_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct aspeed_scu_ic *scu_ic = kzalloc(sizeof(*scu_ic), GFP_KERNEL);
+
+ if (!scu_ic)
+ return -ENOMEM;
+
+ scu_ic->irq_enable = ASPEED_AST2600_SCU_IC0_ENABLE;
+ scu_ic->irq_shift = ASPEED_AST2600_SCU_IC0_SHIFT;
+ scu_ic->num_irqs = ASPEED_AST2600_SCU_IC0_NUM_IRQS;
+
+ return aspeed_scu_ic_of_init_common(scu_ic, node);
+}
+
+static int __init aspeed_ast2600_scu_ic1_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct aspeed_scu_ic *scu_ic = kzalloc(sizeof(*scu_ic), GFP_KERNEL);
+
+ if (!scu_ic)
+ return -ENOMEM;
+
+ scu_ic->irq_enable = ASPEED_AST2600_SCU_IC1_ENABLE;
+ scu_ic->irq_shift = ASPEED_AST2600_SCU_IC1_SHIFT;
+ scu_ic->num_irqs = ASPEED_AST2600_SCU_IC1_NUM_IRQS;
+
+ return aspeed_scu_ic_of_init_common(scu_ic, node);
+}
+
+IRQCHIP_DECLARE(ast2400_scu_ic, "aspeed,ast2400-scu-ic", aspeed_scu_ic_of_init);
+IRQCHIP_DECLARE(ast2500_scu_ic, "aspeed,ast2500-scu-ic", aspeed_scu_ic_of_init);
+IRQCHIP_DECLARE(ast2600_scu_ic0, "aspeed,ast2600-scu-ic0",
+ aspeed_ast2600_scu_ic0_of_init);
+IRQCHIP_DECLARE(ast2600_scu_ic1, "aspeed,ast2600-scu-ic1",
+ aspeed_ast2600_scu_ic1_of_init);
--
1.8.3.1
Add nodes for the interrupt controllers provided by the SCU.
Signed-off-by: Eddie James <[email protected]>
---
arch/arm/boot/dts/aspeed-g6.dtsi | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/arch/arm/boot/dts/aspeed-g6.dtsi b/arch/arm/boot/dts/aspeed-g6.dtsi
index 3a1422f..d89f1e6 100644
--- a/arch/arm/boot/dts/aspeed-g6.dtsi
+++ b/arch/arm/boot/dts/aspeed-g6.dtsi
@@ -159,6 +159,24 @@
compatible = "aspeed,ast2600-smpmem";
reg = <0x180 0x40>;
};
+
+ scu_ic0: interrupt-controller@0 {
+ #interrupt-cells = <1>;
+ compatible = "aspeed,ast2600-scu-ic0";
+ reg = <0x560 0x4>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-controller;
+ };
+
+ scu_ic1: interrupt-controller@1 {
+ #interrupt-cells = <1>;
+ compatible = "aspeed,ast2600-scu-ic1";
+ reg = <0x570 0x4>;
+ interrupt-parent = <&gic>;
+ interrupts = <GIC_SPI 41 IRQ_TYPE_LEVEL_HIGH>;
+ interrupt-controller;
+ };
};
rng: hwrng@1e6e2524 {
--
1.8.3.1
Document the Aspeed SCU interrupt controller and add an include file
for the interrupts it provides.
Signed-off-by: Eddie James <[email protected]>
---
.../interrupt-controller/aspeed,ast2xxx-scu-ic.txt | 26 ++++++++++++++++++++++
MAINTAINERS | 7 ++++++
.../interrupt-controller/aspeed-scu-ic.h | 23 +++++++++++++++++++
3 files changed, 56 insertions(+)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt
create mode 100644 include/dt-bindings/interrupt-controller/aspeed-scu-ic.h
diff --git a/Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt b/Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt
new file mode 100644
index 0000000..baa3780
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt
@@ -0,0 +1,26 @@
+Aspeed AST25XX and AST26XX SCU Interrupt Controller
+
+Required Properties:
+ - #interrupt-cells : must be 1
+ - compatible : must be "aspeed,ast2500-scu-ic",
+ "aspeed,ast2600-scu-ic0" or
+ "aspeed,ast2600-scu-ic1"
+ - reg : address and size of the SCU register
+ associated with the controller
+ - interrupts : interrupt from the parent controller
+ - interrupt-controller : indicates that the controlle receives and
+ fires new interrupts for child busses
+
+Example:
+
+ syscon@1e6e2000 {
+ ranges = <0 0x1e6e2000 0x1a8>;
+
+ scu_ic: interrupt-controller@18 {
+ #interrupt-cells = <1>;
+ compatible = "aspeed,ast2500-scu-ic";
+ reg = <0x18 0x04>;
+ interrupts = <21>;
+ interrupt-controller;
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 7ce3c95..c7e028c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2651,6 +2651,13 @@ S: Maintained
F: drivers/pinctrl/aspeed/
F: Documentation/devicetree/bindings/pinctrl/aspeed,*
+ASPEED SCU INTERRUPT CONTROLLER DRIVER
+M: Eddie James <[email protected]>
+L: [email protected] (moderated for non-subscribers)
+S: Maintained
+F: Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt
+F: include/dt-bindings/interrupt-controller/aspeed-scu-ic.h
+
ASPEED VIDEO ENGINE DRIVER
M: Eddie James <[email protected]>
L: [email protected]
diff --git a/include/dt-bindings/interrupt-controller/aspeed-scu-ic.h b/include/dt-bindings/interrupt-controller/aspeed-scu-ic.h
new file mode 100644
index 0000000..f315d5a
--- /dev/null
+++ b/include/dt-bindings/interrupt-controller/aspeed-scu-ic.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef _DT_BINDINGS_INTERRUPT_CONTROLLER_ASPEED_SCU_IC_H_
+#define _DT_BINDINGS_INTERRUPT_CONTROLLER_ASPEED_SCU_IC_H_
+
+#define ASPEED_SCU_IC_VGA_CURSOR_CHANGE 0
+#define ASPEED_SCU_IC_VGA_SCRATCH_REG_CHANGE 1
+
+#define ASPEED_AST2500_SCU_IC_PCIE_RESET_LO_TO_HI 2
+#define ASPEED_AST2500_SCU_IC_PCIE_RESET_HI_TO_LO 3
+#define ASPEED_AST2500_SCU_IC_LPC_RESET_LO_TO_HI 4
+#define ASPEED_AST2500_SCU_IC_LPC_RESET_HI_TO_LO 5
+#define ASPEED_AST2500_SCU_IC_ISSUE_MSI 6
+
+#define ASPEED_AST2600_SCU_IC0_PCIE_PERST_LO_TO_HI 2
+#define ASPEED_AST2600_SCU_IC0_PCIE_PERST_HI_TO_LO 3
+#define ASPEED_AST2600_SCU_IC0_PCIE_RCRST_LO_TO_HI 4
+#define ASPEED_AST2600_SCU_IC0_PCIE_RCRST_HI_TO_LO 5
+
+#define ASPEED_AST2600_SCU_IC1_LPC_RESET_LO_TO_HI 0
+#define ASPEED_AST2600_SCU_IC1_LPC_RESET_HI_TO_LO 1
+
+#endif /* _DT_BINDINGS_INTERRUPT_CONTROLLER_ASPEED_SCU_IC_H_ */
--
1.8.3.1
On Fri, 27 Sep 2019 15:58:46 -0500, Eddie James wrote:
> Document the Aspeed SCU interrupt controller and add an include file
> for the interrupts it provides.
>
> Signed-off-by: Eddie James <[email protected]>
> ---
> .../interrupt-controller/aspeed,ast2xxx-scu-ic.txt | 26 ++++++++++++++++++++++
> MAINTAINERS | 7 ++++++
> .../interrupt-controller/aspeed-scu-ic.h | 23 +++++++++++++++++++
> 3 files changed, 56 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt
> create mode 100644 include/dt-bindings/interrupt-controller/aspeed-scu-ic.h
>
Reviewed-by: Rob Herring <[email protected]>
On Sat, 28 Sep 2019, at 06:28, Eddie James wrote:
> The Aspeed SOCs provide some interrupts through the System Control
> Unit registers. Add an interrupt controller that provides these
> interrupts to the system.
>
> Signed-off-by: Eddie James <[email protected]>
> ---
> Changes since v1:
> - add a spinlock to protect read-modify-write operation for irq masking
> - use readl/writel relaxed versions
What's your motivation? I might have missed some comments on v1. The
descriptions make me slightly nervous (not guaranteed to be ordered wrt
spinlocks).
> - add a comment explaining the irq status/enable register
> - provide affinity callback that returns -EINVAL
>
> MAINTAINERS | 1 +
> drivers/irqchip/Makefile | 2 +-
> drivers/irqchip/irq-aspeed-scu-ic.c | 233 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 235 insertions(+), 1 deletion(-)
> create mode 100644 drivers/irqchip/irq-aspeed-scu-ic.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index c7e028c..b6db122 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2656,6 +2656,7 @@ M: Eddie James <[email protected]>
> L: [email protected] (moderated for non-subscribers)
> S: Maintained
>
> F: Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt
> +F: drivers/irqchip/irq-aspeed-scu-ic.c
> F: include/dt-bindings/interrupt-controller/aspeed-scu-ic.h
>
> ASPEED VIDEO ENGINE DRIVER
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index cc7c439..fce6b1d 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -86,7 +86,7 @@ obj-$(CONFIG_MVEBU_PIC) += irq-mvebu-pic.o
> obj-$(CONFIG_MVEBU_SEI) += irq-mvebu-sei.o
> obj-$(CONFIG_LS_SCFG_MSI) += irq-ls-scfg-msi.o
> obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o
> -obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o irq-aspeed-i2c-ic.o
> +obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o irq-aspeed-i2c-ic.o
> irq-aspeed-scu-ic.o
> obj-$(CONFIG_STM32_EXTI) += irq-stm32-exti.o
> obj-$(CONFIG_QCOM_IRQ_COMBINER) += qcom-irq-combiner.o
> obj-$(CONFIG_IRQ_UNIPHIER_AIDET) += irq-uniphier-aidet.o
> diff --git a/drivers/irqchip/irq-aspeed-scu-ic.c
> b/drivers/irqchip/irq-aspeed-scu-ic.c
> new file mode 100644
> index 0000000..64c3ac4
> --- /dev/null
> +++ b/drivers/irqchip/irq-aspeed-scu-ic.c
> @@ -0,0 +1,233 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Aspeed AST24XX, AST25XX, and AST26XX SCU Interrupt Controller
> + * Copyright 2019 IBM Corporation
> + *
> + * Eddie James <[email protected]>
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <linux/io.h>
> +#include <linux/spinlock.h>
> +
> +#define ASPEED_SCU_IC_SHIFT 0
> +#define ASPEED_SCU_IC_ENABLE GENMASK(6, ASPEED_SCU_IC_SHIFT)
> +#define ASPEED_SCU_IC_NUM_IRQS 7
> +#define ASPEED_SCU_IC_STATUS_SHIFT 16
> +
> +#define ASPEED_AST2600_SCU_IC0_SHIFT 0
> +#define ASPEED_AST2600_SCU_IC0_ENABLE \
> + GENMASK(5, ASPEED_AST2600_SCU_IC0_SHIFT)
> +#define ASPEED_AST2600_SCU_IC0_NUM_IRQS 6
> +
> +#define ASPEED_AST2600_SCU_IC1_SHIFT 4
> +#define ASPEED_AST2600_SCU_IC1_ENABLE \
> + GENMASK(5, ASPEED_AST2600_SCU_IC1_SHIFT)
> +#define ASPEED_AST2600_SCU_IC1_NUM_IRQS 2
> +
> +struct aspeed_scu_ic {
> + unsigned long irq_enable;
> + unsigned long irq_shift;
> + unsigned int num_irqs;
> + void __iomem *reg;
> + struct irq_domain *irq_domain;
> + spinlock_t lock;
> +};
> +
> +static void aspeed_scu_ic_irq_handler(struct irq_desc *desc)
> +{
> + unsigned int irq;
> + unsigned long bit;
> + unsigned long enabled;
> + unsigned long max;
> + unsigned long status;
> + struct aspeed_scu_ic *scu_ic = irq_desc_get_handler_data(desc);
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> +
> + chained_irq_enter(chip, desc);
> +
> + /*
> + * The SCU IC has just one register to control its operation and read
> + * status. The interrupt enable bits occupy the lower 16 bits of the
> + * register, while the interrupt status bits occupy the upper 16 bits.
> + * The status bit for a given interrupt is always 16 bits shifted from
> + * the enable bit for the same interrupt.
> + * Therefore, perform the IRQ operations in the enable bit space by
> + * shifting the status down to get the mapping and then back up to
> + * clear the bit.
> + */
> + status = readl_relaxed(scu_ic->reg);
> + enabled = status & scu_ic->irq_enable;
> + status = (status >> ASPEED_SCU_IC_STATUS_SHIFT) & enabled;
> +
> + bit = scu_ic->irq_shift;
> + max = scu_ic->num_irqs + bit;
> +
> + for_each_set_bit_from(bit, &status, max) {
> + irq = irq_find_mapping(scu_ic->irq_domain,
> + bit - scu_ic->irq_shift);
> + generic_handle_irq(irq);
> +
> + writel_relaxed(enabled | BIT(bit + ASPEED_SCU_IC_STATUS_SHIFT),
> + scu_ic->reg);
> + }
> +
> + chained_irq_exit(chip, desc);
> +}
> +
> +static void aspeed_scu_ic_irq_mask(struct irq_data *data)
> +{
> + struct aspeed_scu_ic *scu_ic = irq_data_get_irq_chip_data(data);
> + unsigned long bit = BIT(data->hwirq + scu_ic->irq_shift);
> + unsigned long flags;
> + unsigned long reg;
> +
> + spin_lock_irqsave(&scu_ic->lock, flags);
The SCU is represented by a syscon in the devicetree, which has a regmap,
which does it's own locking internally. You could use regmap_update_bits()
to do an atomic read/modify/write and this will provide consistency for
other SCU drivers that might be accessing shared registers. Nothing else
should _currently_ be touching the SCU IRQ status/enable register, but
using the regmap would give us a consistent approach across all SCU
drivers.
Andrew