[PATCH v4 3/6] irqchip: Add Loongson PCH PIC controller

Jiaxun Yang
2020-05-16T08:29:55Z

This controller appears on Loongson LS7A family of PCH to transform
interrupts from devices into HyperTransport vectorized interrrupts
and send them to procrssor's HT vector controller.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
v2:
- Style clean-ups
- Use IRQ_FASTEOI_HIERARCHY_HANDLERS
- Move lock into bitclr & bitset
- Make loongson,pic-base-vec as required property
v4:
- Fix variable declear ordering
- Remove irqsave for spin-locks
---
drivers/irqchip/Kconfig | 9 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-loongson-pch-pic.c | 243 +++++++++++++++++++++++++
3 files changed, 253 insertions(+)
create mode 100644 drivers/irqchip/irq-loongson-pch-pic.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index de4564e2ea88..5524a621638c 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -540,4 +540,13 @@ config LOONGSON_HTVEC
help
Support for the Loongson3 HyperTransport Interrupt Vector Controller.

+config LOONGSON_PCH_PIC
+ bool "Loongson PCH PIC Controller"
+ depends on MACH_LOONGSON64 || COMPILE_TEST
+ default MACH_LOONGSON64
+ select IRQ_DOMAIN_HIERARCHY
+ select IRQ_FASTEOI_HIERARCHY_HANDLERS
+ help
+ Support for the Loongson PCH PIC Controller.
+
endmenu
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 74561879f5a7..acc72331cec8 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -108,3 +108,4 @@ obj-$(CONFIG_TI_SCI_INTA_IRQCHIP) += irq-ti-sci-inta.o
obj-$(CONFIG_LOONGSON_LIOINTC) += irq-loongson-liointc.o
obj-$(CONFIG_LOONGSON_HTPIC) += irq-loongson-htpic.o
obj-$(CONFIG_LOONGSON_HTVEC) += irq-loongson-htvec.o
+obj-$(CONFIG_LOONGSON_PCH_PIC) += irq-loongson-pch-pic.o
diff --git a/drivers/irqchip/irq-loongson-pch-pic.c b/drivers/irqchip/irq-loongson-pch-pic.c
new file mode 100644
index 000000000000..2a05b9305012
--- /dev/null
+++ b/drivers/irqchip/irq-loongson-pch-pic.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
+ * Loongson PCH PIC support
+ */
+
+#define pr_fmt(fmt) "pch-pic: " fmt
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+
+/* Registers */
+#define PCH_PIC_MASK 0x20
+#define PCH_PIC_HTMSI_EN 0x40
+#define PCH_PIC_EDGE 0x60
+#define PCH_PIC_CLR 0x80
+#define PCH_PIC_AUTO0 0xc0
+#define PCH_PIC_AUTO1 0xe0
+#define PCH_INT_ROUTE(irq) (0x100 + irq)
+#define PCH_INT_HTVEC(irq) (0x200 + irq)
+#define PCH_PIC_POL 0x3e0
+
+#define PIC_COUNT_PER_REG 32
+#define PIC_REG_COUNT 2
+#define PIC_COUNT (PIC_COUNT_PER_REG * PIC_REG_COUNT)
+#define PIC_REG_IDX(irq_id) ((irq_id) / PIC_COUNT_PER_REG)
+#define PIC_REG_BIT(irq_id) ((irq_id) % PIC_COUNT_PER_REG)
+
+struct pch_pic {
+ void __iomem *base;
+ struct irq_domain *pic_domain;
+ u32 ht_vec_base;
+ raw_spinlock_t pic_lock;
+};
+
+static void pch_pic_bitset(struct pch_pic *priv, int offset, int bit)
+{
+ u32 reg;
+ void __iomem *addr = priv->base + offset + PIC_REG_IDX(bit) * 4;
+
+ raw_spin_lock(&priv->pic_lock);
+ reg = readl(addr);
+ reg |= BIT(PIC_REG_BIT(bit));
+ writel(reg, addr);
+ raw_spin_unlock(&priv->pic_lock);
+}
+
+static void pch_pic_bitclr(struct pch_pic *priv, int offset, int bit)
+{
+ u32 reg;
+ void __iomem *addr = priv->base + offset + PIC_REG_IDX(bit) * 4;
+
+ raw_spin_lock(&priv->pic_lock);
+ reg = readl(addr);
+ reg &= ~BIT(PIC_REG_BIT(bit));
+ writel(reg, addr);
+ raw_spin_unlock(&priv->pic_lock);
+}
+
+static void pch_pic_eoi_irq(struct irq_data *d)
+{
+ u32 idx = PIC_REG_IDX(d->hwirq);
+ struct pch_pic *priv = irq_data_get_irq_chip_data(d);
+
+ writel(BIT(PIC_REG_BIT(d->hwirq)),
+ priv->base + PCH_PIC_CLR + idx * 4);
+}
+
+static void pch_pic_mask_irq(struct irq_data *d)
+{
+ struct pch_pic *priv = irq_data_get_irq_chip_data(d);
+
+ pch_pic_bitset(priv, PCH_PIC_MASK, d->hwirq);
+ irq_chip_mask_parent(d);
+}
+
+static void pch_pic_unmask_irq(struct irq_data *d)
+{
+ struct pch_pic *priv = irq_data_get_irq_chip_data(d);
+
+ irq_chip_unmask_parent(d);
+ pch_pic_bitclr(priv, PCH_PIC_MASK, d->hwirq);
+}
+
+static int pch_pic_set_type(struct irq_data *d, unsigned int type)
+{
+ struct pch_pic *priv = irq_data_get_irq_chip_data(d);
+ int ret = 0;
+
+ switch (type) {
+ case IRQ_TYPE_EDGE_RISING:
+ pch_pic_bitset(priv, PCH_PIC_EDGE, d->hwirq);
+ pch_pic_bitclr(priv, PCH_PIC_POL, d->hwirq);
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ pch_pic_bitset(priv, PCH_PIC_EDGE, d->hwirq);
+ pch_pic_bitset(priv, PCH_PIC_POL, d->hwirq);
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ pch_pic_bitclr(priv, PCH_PIC_EDGE, d->hwirq);
+ pch_pic_bitclr(priv, PCH_PIC_POL, d->hwirq);
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ pch_pic_bitclr(priv, PCH_PIC_EDGE, d->hwirq);
+ pch_pic_bitset(priv, PCH_PIC_POL, d->hwirq);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
+static struct irq_chip pch_pic_irq_chip = {
+ .name = "PCH PIC",
+ .irq_mask = pch_pic_mask_irq,
+ .irq_unmask = pch_pic_unmask_irq,
+ .irq_ack = irq_chip_ack_parent,
+ .irq_eoi = pch_pic_eoi_irq,
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+ .irq_set_type = pch_pic_set_type,
+};
+
+static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ int err;
+ unsigned int type;
+ unsigned long hwirq;
+ struct irq_fwspec fwspec;
+ struct pch_pic *priv = domain->host_data;
+
+ irq_domain_translate_twocell(domain, arg, &hwirq, &type);
+
+ fwspec.fwnode = domain->parent->fwnode;
+ fwspec.param_count = 1;
+ fwspec.param[0] = hwirq + priv->ht_vec_base;
+
+ err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
+ if (err)
+ return err;
+
+ irq_domain_set_info(domain, virq, hwirq,
+ &pch_pic_irq_chip, priv,
+ handle_fasteoi_ack_irq, NULL, NULL);
+ irq_set_probe(virq);
+
+ return 0;
+}
+
+static const struct irq_domain_ops pch_pic_domain_ops = {
+ .translate = irq_domain_translate_twocell,
+ .alloc = pch_pic_alloc,
+ .free = irq_domain_free_irqs_parent,
+};
+
+static void pch_pic_reset(struct pch_pic *priv)
+{
+ int i;
+
+ for (i = 0; i < PIC_COUNT; i++) {
+ /* Write vectore ID */
+ writeb(priv->ht_vec_base + i, priv->base + PCH_INT_HTVEC(i));
+ /* Hardcode route to HT0 Lo */
+ writeb(1, priv->base + PCH_INT_ROUTE(i));
+ }
+
+ for (i = 0; i < PIC_REG_COUNT; i++) {
+ /* Clear IRQ cause registers, mask all interrupts */
+ writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_MASK + 4 * i);
+ writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_CLR + 4 * i);
+ /* Clear auto bounce, we don't need that */
+ writel_relaxed(0, priv->base + PCH_PIC_AUTO0 + 4 * i);
+ writel_relaxed(0, priv->base + PCH_PIC_AUTO1 + 4 * i);
+ /* Enable HTMSI transformer */
+ writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_HTMSI_EN + 4 * i);
+ }
+}
+
+static int pch_pic_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct pch_pic *priv;
+ struct irq_domain *parent_domain;
+ int err;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ raw_spin_lock_init(&priv->pic_lock);
+ priv->base = of_iomap(node, 0);
+ if (!priv->base) {
+ err = -ENOMEM;
+ goto free_priv;
+ }
+
+ parent_domain = irq_find_host(parent);
+ if (!parent_domain) {
+ pr_err("Failed to find the parent domain\n");
+ err = -ENXIO;
+ goto iounmap_base;
+ }
+
+ if (of_property_read_u32(node, "loongson,pic-base-vec",
+ &priv->ht_vec_base)) {
+ pr_err("Failed to determine pic-base-vec\n");
+ err = -EINVAL;
+ goto iounmap_base;
+ }
+
+ priv->pic_domain = irq_domain_create_hierarchy(parent_domain, 0,
+ PIC_COUNT,
+ of_node_to_fwnode(node),
+ &pch_pic_domain_ops,
+ priv);
+ if (!priv->pic_domain) {
+ pr_err("Failed to create IRQ domain\n");
+ err = -ENOMEM;
+ goto iounmap_base;
+ }
+
+ pch_pic_reset(priv);
+
+ return 0;
+
+iounmap_base:
+ iounmap(priv->base);
+free_priv:
+ kfree(priv);
+
+ return err;
+}
+
+IRQCHIP_DECLARE(pch_pic, "loongson,pch-pic-1.0", pch_pic_of_init);
--
2.26.2