[PATCH v2 11/19] irqchip: Add support for LAN966x OIC

Herve Codina
2024-05-27T16:15:19Z

The Microchip LAN966x outband interrupt controller (OIC) maps the
internal interrupt sources of the LAN966x device to an external
interrupt.
When the LAN966x device is used as a PCI device, the external interrupt
is routed to the PCI interrupt.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
drivers/irqchip/Kconfig | 12 ++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-lan966x-oic.c | 308 ++++++++++++++++++++++++++++++
3 files changed, 321 insertions(+)
create mode 100644 drivers/irqchip/irq-lan966x-oic.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 14464716bacb..348f34525d23 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -169,6 +169,18 @@ config IXP4XX_IRQ
select IRQ_DOMAIN
select SPARSE_IRQ

+config LAN966X_OIC
+ tristate "Microchip LAN966x OIC Support"
+ select GENERIC_IRQ_CHIP
+ select IRQ_DOMAIN
+ help
+ Enable support for the LAN966x Outbound Interrupt Controller.
+ This controller is present on the Microchip LAN966x PCI device and
+ maps the internal interrupts sources to PCIe interrupt.
+
+ To compile this driver as a module, choose M here: the module
+ will be called irq-lan966x-oic.
+
config MADERA_IRQ
tristate

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index d9dc3d99aaa8..9f6f88274bec 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -104,6 +104,7 @@ obj-$(CONFIG_IMX_IRQSTEER) += irq-imx-irqsteer.o
obj-$(CONFIG_IMX_INTMUX) += irq-imx-intmux.o
obj-$(CONFIG_IMX_MU_MSI) += irq-imx-mu-msi.o
obj-$(CONFIG_MADERA_IRQ) += irq-madera.o
+obj-$(CONFIG_LAN966X_OIC) += irq-lan966x-oic.o
obj-$(CONFIG_LS1X_IRQ) += irq-ls1x.o
obj-$(CONFIG_TI_SCI_INTR_IRQCHIP) += irq-ti-sci-intr.o
obj-$(CONFIG_TI_SCI_INTA_IRQCHIP) += irq-ti-sci-inta.o
diff --git a/drivers/irqchip/irq-lan966x-oic.c b/drivers/irqchip/irq-lan966x-oic.c
new file mode 100644
index 000000000000..a5f64610e62d
--- /dev/null
+++ b/drivers/irqchip/irq-lan966x-oic.c
@@ -0,0 +1,308 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the Microchip LAN966x outbound interrupt controller
+ *
+ * Copyright (c) 2024 Technology Inc. and its subsidiaries.
+ *
+ * Authors:
+ * Horatiu Vultur <horatiu.vultur@microchip.com>
+ * Clément Léger <clement.leger@bootlin.com>
+ * Herve Codina <herve.codina@bootlin.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/build_bug.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqchip.h>
+#include <linux/irq.h>
+#include <linux/iopoll.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+
+struct lan966x_oic_chip_regs {
+ int reg_off_ena_set;
+ int reg_off_ena_clr;
+ int reg_off_sticky;
+ int reg_off_ident;
+ int reg_off_map;
+};
+
+struct lan966x_oic_data {
+ struct irq_domain *domain;
+ void __iomem *regs;
+ int irq;
+};
+
+#define LAN966X_OIC_NR_IRQ 86
+
+/* Interrupt sticky status */
+#define LAN966X_OIC_INTR_STICKY 0x30
+#define LAN966X_OIC_INTR_STICKY1 0x34
+#define LAN966X_OIC_INTR_STICKY2 0x38
+
+/* Interrupt enable */
+#define LAN966X_OIC_INTR_ENA 0x48
+#define LAN966X_OIC_INTR_ENA1 0x4c
+#define LAN966X_OIC_INTR_ENA2 0x50
+
+/* Atomic clear of interrupt enable */
+#define LAN966X_OIC_INTR_ENA_CLR 0x54
+#define LAN966X_OIC_INTR_ENA_CLR1 0x58
+#define LAN966X_OIC_INTR_ENA_CLR2 0x5c
+
+/* Atomic set of interrupt */
+#define LAN966X_OIC_INTR_ENA_SET 0x60
+#define LAN966X_OIC_INTR_ENA_SET1 0x64
+#define LAN966X_OIC_INTR_ENA_SET2 0x68
+
+/* Mapping of source to destination interrupts (_n = 0..8) */
+#define LAN966X_OIC_DST_INTR_MAP(_n) (0x78 + (_n) * 4)
+#define LAN966X_OIC_DST_INTR_MAP1(_n) (0x9c + (_n) * 4)
+#define LAN966X_OIC_DST_INTR_MAP2(_n) (0xc0 + (_n) * 4)
+
+/* Currently active interrupt sources per destination (_n = 0..8) */
+#define LAN966X_OIC_DST_INTR_IDENT(_n) (0xe4 + (_n) * 4)
+#define LAN966X_OIC_DST_INTR_IDENT1(_n) (0x108 + (_n) * 4)
+#define LAN966X_OIC_DST_INTR_IDENT2(_n) (0x12c + (_n) * 4)
+
+static unsigned int lan966x_oic_irq_startup(struct irq_data *data)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+ struct irq_chip_type *ct = irq_data_get_chip_type(data);
+ struct lan966x_oic_chip_regs *chip_regs = gc->private;
+ u32 map;
+
+ irq_gc_lock(gc);
+
+ /* Map the source interrupt to the destination */
+ map = irq_reg_readl(gc, chip_regs->reg_off_map);
+ map |= data->mask;
+ irq_reg_writel(gc, map, chip_regs->reg_off_map);
+
+ irq_gc_unlock(gc);
+
+ ct->chip.irq_ack(data);
+ ct->chip.irq_unmask(data);
+
+ return 0;
+}
+
+static void lan966x_oic_irq_shutdown(struct irq_data *data)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
+ struct irq_chip_type *ct = irq_data_get_chip_type(data);
+ struct lan966x_oic_chip_regs *chip_regs = gc->private;
+ u32 map;
+
+ ct->chip.irq_mask(data);
+
+ irq_gc_lock(gc);
+
+ /* Unmap the interrupt */
+ map = irq_reg_readl(gc, chip_regs->reg_off_map);
+ map &= ~data->mask;
+ irq_reg_writel(gc, map, chip_regs->reg_off_map);
+
+ irq_gc_unlock(gc);
+}
+
+static int lan966x_oic_irq_set_type(struct irq_data *data,
+ unsigned int flow_type)
+{
+ if (flow_type != IRQ_TYPE_LEVEL_HIGH) {
+ pr_err("lan966x oic doesn't support flow type %d\n", flow_type);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void lan966x_oic_irq_handler_domain(struct irq_domain *d, u32 first_irq)
+{
+ struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, first_irq);
+ struct lan966x_oic_chip_regs *chip_regs = gc->private;
+ unsigned long ident;
+ unsigned int hwirq;
+
+ ident = irq_reg_readl(gc, chip_regs->reg_off_ident);
+ if (!ident)
+ return;
+
+ for_each_set_bit(hwirq, &ident, 32)
+ generic_handle_domain_irq(d, hwirq + first_irq);
+}
+
+static void lan966x_oic_irq_handler(struct irq_desc *desc)
+{
+ struct irq_domain *d = irq_desc_get_handler_data(desc);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+
+ chained_irq_enter(chip, desc);
+ lan966x_oic_irq_handler_domain(d, 0);
+ lan966x_oic_irq_handler_domain(d, 32);
+ lan966x_oic_irq_handler_domain(d, 64);
+ chained_irq_exit(chip, desc);
+}
+
+static struct lan966x_oic_chip_regs lan966x_oic_chip_regs[3] = {
+ {
+ .reg_off_ena_set = LAN966X_OIC_INTR_ENA_SET,
+ .reg_off_ena_clr = LAN966X_OIC_INTR_ENA_CLR,
+ .reg_off_sticky = LAN966X_OIC_INTR_STICKY,
+ .reg_off_ident = LAN966X_OIC_DST_INTR_IDENT(0),
+ .reg_off_map = LAN966X_OIC_DST_INTR_MAP(0),
+ }, {
+ .reg_off_ena_set = LAN966X_OIC_INTR_ENA_SET1,
+ .reg_off_ena_clr = LAN966X_OIC_INTR_ENA_CLR1,
+ .reg_off_sticky = LAN966X_OIC_INTR_STICKY1,
+ .reg_off_ident = LAN966X_OIC_DST_INTR_IDENT1(0),
+ .reg_off_map = LAN966X_OIC_DST_INTR_MAP1(0),
+ }, {
+ .reg_off_ena_set = LAN966X_OIC_INTR_ENA_SET2,
+ .reg_off_ena_clr = LAN966X_OIC_INTR_ENA_CLR2,
+ .reg_off_sticky = LAN966X_OIC_INTR_STICKY2,
+ .reg_off_ident = LAN966X_OIC_DST_INTR_IDENT2(0),
+ .reg_off_map = LAN966X_OIC_DST_INTR_MAP2(0),
+ }
+};
+
+static void lan966x_oic_chip_init(struct lan966x_oic_data *lan966x_oic,
+ struct irq_chip_generic *gc,
+ struct lan966x_oic_chip_regs *chip_regs)
+{
+ gc->reg_base = lan966x_oic->regs;
+ gc->chip_types[0].regs.enable = chip_regs->reg_off_ena_set;
+ gc->chip_types[0].regs.disable = chip_regs->reg_off_ena_clr;
+ gc->chip_types[0].regs.ack = chip_regs->reg_off_sticky;
+ gc->chip_types[0].chip.irq_startup = lan966x_oic_irq_startup;
+ gc->chip_types[0].chip.irq_shutdown = lan966x_oic_irq_shutdown;
+ gc->chip_types[0].chip.irq_set_type = lan966x_oic_irq_set_type;
+ gc->chip_types[0].chip.irq_mask = irq_gc_mask_disable_reg;
+ gc->chip_types[0].chip.irq_unmask = irq_gc_unmask_enable_reg;
+ gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
+ gc->private = chip_regs;
+
+ /* Disable all interrupts handled by this chip */
+ irq_reg_writel(gc, ~0, chip_regs->reg_off_ena_clr);
+}
+
+static void lan966x_oic_chip_exit(struct irq_chip_generic *gc)
+{
+ /* Disable and ack all interrupts handled by this chip */
+ irq_reg_writel(gc, ~0, gc->chip_types[0].regs.disable);
+ irq_reg_writel(gc, ~0, gc->chip_types[0].regs.ack);
+}
+
+static int lan966x_oic_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct lan966x_oic_data *lan966x_oic;
+ struct device *dev = &pdev->dev;
+ struct irq_chip_generic *gc;
+ int ret;
+ int i;
+
+ lan966x_oic = devm_kmalloc(dev, sizeof(*lan966x_oic), GFP_KERNEL);
+ if (!lan966x_oic)
+ return -ENOMEM;
+
+ lan966x_oic->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(lan966x_oic->regs))
+ return dev_err_probe(dev, PTR_ERR(lan966x_oic->regs),
+ "failed to map resource\n");
+
+ lan966x_oic->domain = irq_domain_alloc_linear(of_node_to_fwnode(node),
+ LAN966X_OIC_NR_IRQ,
+ &irq_generic_chip_ops,
+ NULL);
+ if (!lan966x_oic->domain) {
+ dev_err(dev, "failed to create an IRQ domain\n");
+ return -EINVAL;
+ }
+
+ lan966x_oic->irq = platform_get_irq(pdev, 0);
+ if (lan966x_oic->irq < 0) {
+ ret = dev_err_probe(dev, lan966x_oic->irq,
+ "failed to get the IRQ\n");
+ goto err_domain_free;
+ }
+
+ ret = irq_alloc_domain_generic_chips(lan966x_oic->domain, 32, 1,
+ "lan966x-oic", handle_level_irq, 0,
+ 0, 0);
+ if (ret) {
+ dev_err_probe(dev, ret, "failed to alloc irq domain gc\n");
+ goto err_domain_free;
+ }
+
+ /* Init chips */
+ BUILD_BUG_ON(DIV_ROUND_UP(LAN966X_OIC_NR_IRQ, 32) !=
+ ARRAY_SIZE(lan966x_oic_chip_regs));
+ for (i = 0; i < ARRAY_SIZE(lan966x_oic_chip_regs); i++) {
+ gc = irq_get_domain_generic_chip(lan966x_oic->domain, i * 32);
+ lan966x_oic_chip_init(lan966x_oic, gc,
+ &lan966x_oic_chip_regs[i]);
+ }
+
+ irq_set_chained_handler_and_data(lan966x_oic->irq,
+ lan966x_oic_irq_handler,
+ lan966x_oic->domain);
+
+ irq_domain_publish(lan966x_oic->domain);
+ platform_set_drvdata(pdev, lan966x_oic);
+ return 0;
+
+err_domain_free:
+ irq_domain_free(lan966x_oic->domain);
+ return ret;
+}
+
+static void lan966x_oic_remove(struct platform_device *pdev)
+{
+ struct lan966x_oic_data *lan966x_oic = platform_get_drvdata(pdev);
+ struct irq_chip_generic *gc;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(lan966x_oic_chip_regs); i++) {
+ gc = irq_get_domain_generic_chip(lan966x_oic->domain, i * 32);
+ lan966x_oic_chip_exit(gc);
+ }
+
+ irq_set_chained_handler_and_data(lan966x_oic->irq, NULL, NULL);
+
+ for (i = 0; i < LAN966X_OIC_NR_IRQ; i++)
+ irq_dispose_mapping(irq_find_mapping(lan966x_oic->domain, i));
+
+ irq_domain_unpublish(lan966x_oic->domain);
+
+ for (i = 0; i < ARRAY_SIZE(lan966x_oic_chip_regs); i++) {
+ gc = irq_get_domain_generic_chip(lan966x_oic->domain, i * 32);
+ irq_remove_generic_chip(gc, ~0, 0, 0);
+ }
+
+ kfree(lan966x_oic->domain->gc);
+ irq_domain_free(lan966x_oic->domain);
+}
+
+static const struct of_device_id lan966x_oic_of_match[] = {
+ { .compatible = "microchip,lan966x-oic" },
+ {} /* sentinel */
+};
+MODULE_DEVICE_TABLE(of, lan966x_oic_of_match);
+
+static struct platform_driver lan966x_oic_driver = {
+ .probe = lan966x_oic_probe,
+ .remove_new = lan966x_oic_remove,
+ .driver = {
+ .name = "lan966x-oic",
+ .of_match_table = lan966x_oic_of_match,
+ },
+};
+module_platform_driver(lan966x_oic_driver);
+
+MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
+MODULE_DESCRIPTION("Microchip LAN966x OIC driver");
+MODULE_LICENSE("GPL");
--
2.45.0