[PATCH 2/4] irqchip: irq-mvebu-pic: new driver for Marvell Armada 7K/8K PIC

Thomas Petazzoni
2016-08-05T14:55:19Z

The Marvell Armada 7K/8K integrates a secondary interrupt controller
very originally named "PIC". It is connected to the main GIC via a
PPI. Amongst other things, this PIC is used for the ARM PMU.

This commit adds a simple irqchip driver for this interrupt
controller. Since this interrupt controller is not needed early at boot
time, we make the driver a proper platform driver rather than use the
IRQCHIP_DECLARE() mechanism.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
drivers/irqchip/Kconfig | 3 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-mvebu-pic.c | 195 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 199 insertions(+)
create mode 100644 drivers/irqchip/irq-mvebu-pic.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index fa33c50..a6f90c5 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -246,6 +246,9 @@ config MVEBU_ODMI
bool
select GENERIC_MSI_IRQ_DOMAIN

+config MVEBU_PIC
+ bool
+
config LS_SCFG_MSI
def_bool y if SOC_LS1021A || ARCH_LAYERSCAPE
depends on PCI && PCI_MSI
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 38853a1..024a78d 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -67,5 +67,6 @@ obj-$(CONFIG_INGENIC_IRQ) += irq-ingenic.o
obj-$(CONFIG_IMX_GPCV2) += irq-imx-gpcv2.o
obj-$(CONFIG_PIC32_EVIC) += irq-pic32-evic.o
obj-$(CONFIG_MVEBU_ODMI) += irq-mvebu-odmi.o
+obj-$(CONFIG_MVEBU_PIC) += irq-mvebu-pic.o
obj-$(CONFIG_LS_SCFG_MSI) += irq-ls-scfg-msi.o
obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o
diff --git a/drivers/irqchip/irq-mvebu-pic.c b/drivers/irqchip/irq-mvebu-pic.c
new file mode 100644
index 0000000..4a3aa7f
--- /dev/null
+++ b/drivers/irqchip/irq-mvebu-pic.c
@@ -0,0 +1,195 @@
+/*
+ * Copyright (C) 2016 Marvell
+ *
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+#define PIC_CAUSE 0x0
+#define PIC_MASK 0x4
+
+#define PIC_MAX_IRQS 32
+#define PIC_MAX_IRQ_MASK ((1UL << PIC_MAX_IRQS) - 1)
+
+struct mvebu_pic {
+ void __iomem *base;
+ u32 parent_irq;
+ struct irq_domain *domain;
+ struct irq_chip irq_chip;
+};
+
+static void mvebu_pic_reset(struct mvebu_pic *pic)
+{
+ /* ACK and mask all interrupts */
+ writel(0, pic->base + PIC_MASK);
+ writel(PIC_MAX_IRQ_MASK, pic->base + PIC_CAUSE);
+}
+
+static void mvebu_pic_eoi_irq(struct irq_data *d)
+{
+ struct mvebu_pic *pic = irq_data_get_irq_chip_data(d);
+
+ writel(1 << d->hwirq, pic->base + PIC_CAUSE);
+}
+
+static void mvebu_pic_mask_irq(struct irq_data *d)
+{
+ struct mvebu_pic *pic = irq_data_get_irq_chip_data(d);
+ u32 reg;
+
+ reg = readl(pic->base + PIC_MASK);
+ reg |= (1 << d->hwirq);
+ writel(reg, pic->base + PIC_MASK);
+}
+
+static void mvebu_pic_unmask_irq(struct irq_data *d)
+{
+ struct mvebu_pic *pic = irq_data_get_irq_chip_data(d);
+ u32 reg;
+
+ reg = readl(pic->base + PIC_MASK);
+ reg &= ~(1 << d->hwirq);
+ writel(reg, pic->base + PIC_MASK);
+}
+
+static int mvebu_pic_irq_map(struct irq_domain *domain, unsigned int virq,
+ irq_hw_number_t hwirq)
+{
+ struct mvebu_pic *pic = domain->host_data;
+
+ irq_set_percpu_devid(virq);
+ irq_set_chip_data(virq, pic);
+ irq_set_chip_and_handler(virq, &pic->irq_chip,
+ handle_percpu_devid_irq);
+ irq_set_status_flags(virq, IRQ_LEVEL);
+ irq_set_probe(virq);
+
+ return 0;
+}
+
+static const struct irq_domain_ops mvebu_pic_domain_ops = {
+ .map = mvebu_pic_irq_map,
+ .xlate = irq_domain_xlate_onecell,
+};
+
+static void mvebu_pic_handle_cascade_irq(struct irq_desc *desc)
+{
+ struct mvebu_pic *pic = irq_desc_get_handler_data(desc);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ unsigned long irqmap, irqn;
+ unsigned int cascade_irq;
+
+ irqmap = readl_relaxed(pic->base + PIC_CAUSE);
+ chained_irq_enter(chip, desc);
+
+ for_each_set_bit(irqn, &irqmap, BITS_PER_LONG) {
+ cascade_irq = irq_find_mapping(pic->domain, irqn);
+ generic_handle_irq(cascade_irq);
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+static void mvebu_pic_enable_percpu_irq(void *data)
+{
+ struct mvebu_pic *pic = data;
+
+ mvebu_pic_reset(pic);
+ enable_percpu_irq(pic->parent_irq, IRQ_TYPE_NONE);
+}
+
+static void mvebu_pic_disable_percpu_irq(void *data)
+{
+ struct mvebu_pic *pic = data;
+
+ disable_percpu_irq(pic->parent_irq);
+}
+
+static int mvebu_pic_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct mvebu_pic *pic;
+ struct irq_chip *irq_chip;
+ struct resource *res;
+
+ pic = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_pic), GFP_KERNEL);
+ if (!pic)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pic->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(pic->base))
+ return PTR_ERR(pic->base);
+
+ irq_chip = &pic->irq_chip;
+ irq_chip->name = dev_name(&pdev->dev);
+ irq_chip->irq_mask = mvebu_pic_mask_irq;
+ irq_chip->irq_unmask = mvebu_pic_unmask_irq;
+ irq_chip->irq_eoi = mvebu_pic_eoi_irq;
+
+ pic->parent_irq = irq_of_parse_and_map(node, 0);
+ if (pic->parent_irq <= 0) {
+ dev_err(&pdev->dev, "Failed to parse parent interrupt\n");
+ return -EINVAL;
+ }
+
+ pic->domain = irq_domain_add_linear(node, PIC_MAX_IRQS,
+ &mvebu_pic_domain_ops, pic);
+ if (!pic->domain) {
+ dev_err(&pdev->dev, "Failed to allocate irq domain\n");
+ return -ENOMEM;
+ }
+
+ irq_set_chained_handler(pic->parent_irq, mvebu_pic_handle_cascade_irq);
+ irq_set_handler_data(pic->parent_irq, pic);
+
+ on_each_cpu(mvebu_pic_enable_percpu_irq, pic, 1);
+
+ platform_set_drvdata(pdev, pic);
+
+ return 0;
+}
+
+static int mvebu_pic_remove(struct platform_device *pdev)
+{
+ struct mvebu_pic *pic = platform_get_drvdata(pdev);
+
+ on_each_cpu(mvebu_pic_disable_percpu_irq, pic, 1);
+ irq_domain_remove(pic->domain);
+
+ return 0;
+}
+
+static const struct of_device_id mvebu_pic_of_match[] = {
+ { .compatible = "marvell,armada-8k-pic", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, mvebu_pic_of_match);
+
+static struct platform_driver mvebu_pic_driver = {
+ .probe = mvebu_pic_probe,
+ .remove = mvebu_pic_remove,
+ .driver = {
+ .name = "mvebu-pic",
+ .of_match_table = mvebu_pic_of_match,
+ },
+};
+module_platform_driver(mvebu_pic_driver);
+
+MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:mvebu_pic");
+
--
2.7.4