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 <eajames@xxxxxxxxxxxxx>
---
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 <eajames@xxxxxxxxxxxxx>
L: linux-aspeed@xxxxxxxxxxxxxxxx (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 <eajames@xxxxxxxxxxxxx>
+ */
+
+#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
