[PATCH V7 6/8] irqchip: add C-SKY APB bus interrupt controller

From: Guo Ren
Date: Sun Sep 30 2018 - 12:20:04 EST

- irq-csky-apb-intc is a simple SOC interrupt controller which is
used in a lot of C-SKY CPU SOC products.

Changelog:
- use "bool ret" instead of "int ret"
- add support-pulse-signal in irq-csky-apb-intc.c
- change name with upstream feed-back
- add INTC_IFR to clear irq-pending
- remove CSKY_VECIRQ_LEGENCY
- change to generic irq chip framework
- add License and Copyright
- use irq_domain_add_linear instead of leagcy

Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
---
drivers/irqchip/Kconfig | 8 ++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-csky-apb-intc.c | 260 ++++++++++++++++++++++++++++++++++++
3 files changed, 269 insertions(+)
create mode 100644 drivers/irqchip/irq-csky-apb-intc.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 92e1c20..bf12549 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -379,6 +379,14 @@ config CSKY_MPINTC
for C-SKY SMP system. In fact it's not mmio map and it use ld/st
to visit the controller's register inside CPU.

+config CSKY_APB_INTC
+ bool "C-SKY APB Interrupt Controller"
+ depends on CSKY
+ help
+ Say yes here to enable C-SKY APB interrupt controller driver used
+ by C-SKY single core SOC system. It use mmio map apb-bus to visit
+ the controller's register.
+
endmenu

config SIFIVE_PLIC
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 6b739ea..72eaf53 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -88,4 +88,5 @@ obj-$(CONFIG_GOLDFISH_PIC) += irq-goldfish-pic.o
obj-$(CONFIG_NDS32) += irq-ativic32.o
obj-$(CONFIG_QCOM_PDC) += qcom-pdc.o
obj-$(CONFIG_CSKY_MPINTC) += irq-csky-mpintc.o
+obj-$(CONFIG_CSKY_APB_INTC) += irq-csky-apb-intc.o
obj-$(CONFIG_SIFIVE_PLIC) += irq-sifive-plic.o
diff --git a/drivers/irqchip/irq-csky-apb-intc.c b/drivers/irqchip/irq-csky-apb-intc.c
new file mode 100644
index 0000000..cfe32a7
--- /dev/null
+++ b/drivers/irqchip/irq-csky-apb-intc.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/module.h>
+#include <linux/irqdomain.h>
+#include <linux/irqchip.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <asm/irq.h>
+#include <asm/io.h>
+
+#define INTC_IRQS 64
+
+#define CK_INTC_ICR 0x00
+#define CK_INTC_PEN31_00 0x14
+#define CK_INTC_PEN63_32 0x2c
+#define CK_INTC_NEN31_00 0x10
+#define CK_INTC_NEN63_32 0x28
+#define CK_INTC_SOURCE 0x40
+#define CK_INTC_DUAL_BASE 0x100
+
+#define GX_INTC_PEN31_00 0x00
+#define GX_INTC_PEN63_32 0x04
+#define GX_INTC_NEN31_00 0x40
+#define GX_INTC_NEN63_32 0x44
+#define GX_INTC_NMASK31_00 0x50
+#define GX_INTC_NMASK63_32 0x54
+#define GX_INTC_SOURCE 0x60
+
+static void __iomem *reg_base;
+static struct irq_domain *root_domain;
+
+static int nr_irq = INTC_IRQS;
+
+/*
+ * When controller support pulse signal, the PEN_reg will hold on signal
+ * without software trigger.
+ *
+ * So, to support pulse signal we need to clear IFR_reg and the address of
+ * IFR_offset is NEN_offset - 8.
+ */
+static void irq_ck_mask_set_bit(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ struct irq_chip_type *ct = irq_data_get_chip_type(d);
+ unsigned long ifr = ct->regs.mask - 8;
+ u32 mask = d->mask;
+
+ irq_gc_lock(gc);
+ *ct->mask_cache |= mask;
+ irq_reg_writel(gc, *ct->mask_cache, ct->regs.mask);
+ irq_reg_writel(gc, irq_reg_readl(gc, ifr) & ~mask, ifr);
+ irq_gc_unlock(gc);
+}
+
+static void __init ck_set_gc(struct device_node *node, void __iomem *reg_base,
+ u32 mask_reg, u32 irq_base)
+{
+ struct irq_chip_generic *gc;
+
+ gc = irq_get_domain_generic_chip(root_domain, irq_base);
+ gc->reg_base = reg_base;
+ gc->chip_types[0].regs.mask = mask_reg;
+ gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
+ gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
+
+ if (of_find_property(node, "csky,support-pulse-signal", NULL))
+ gc->chip_types[0].chip.irq_unmask = irq_ck_mask_set_bit;
+}
+
+static inline u32 build_channel_val(u32 idx, u32 magic)
+{
+ u32 res;
+
+ /*
+ * Set the same index for each channel
+ */
+ res = idx | (idx << 8) | (idx << 16) | (idx << 24);
+
+ /*
+ * Set the channel magic number in descending order.
+ * The magic is 0x00010203 for ck-intc
+ * The magic is 0x03020100 for gx6605s-intc
+ */
+ return res | magic;
+}
+
+static inline void setup_irq_channel(u32 magic, void __iomem *reg_addr)
+{
+ u32 i;
+
+ /* Setup 64 channel slots */
+ for (i = 0; i < INTC_IRQS; i += 4) {
+ writel_relaxed(build_channel_val(i, magic), reg_addr + i);
+ }
+}
+
+static int __init
+ck_intc_init_comm(struct device_node *node, struct device_node *parent)
+{
+ int ret;
+
+ if (parent) {
+ pr_err("C-SKY Intc not a root irq controller\n");
+ return -EINVAL;
+ }
+
+ reg_base = of_iomap(node, 0);
+ if (!reg_base) {
+ pr_err("C-SKY Intc unable to map: %p.\n", node);
+ return -EINVAL;
+ }
+
+ root_domain = irq_domain_add_linear(node, nr_irq, &irq_generic_chip_ops, NULL);
+ if (!root_domain) {
+ pr_err("C-SKY Intc irq_domain_add failed.\n");
+ return -ENOMEM;
+ }
+
+ ret = irq_alloc_domain_generic_chips(root_domain, 32, 1,
+ "csky_intc", handle_level_irq,
+ IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN,
+ 0, 0);
+ if (ret) {
+ pr_err("C-SKY Intc irq_alloc_gc failed.\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static inline bool handle_irq_perbit(struct pt_regs *regs, u32 hwirq, u32 irq_base)
+{
+ u32 irq;
+
+ if (hwirq == 0) return 0;
+
+ while (hwirq) {
+ irq = __ffs(hwirq);
+ hwirq &= ~BIT(irq);
+ handle_domain_irq(root_domain, irq_base + irq, regs);
+ }
+
+ return 1;
+}
+
+/* gx6605s 64 irqs interrupt controller */
+static void gx_irq_handler(struct pt_regs *regs)
+{
+ bool ret;
+
+ do {
+ ret = handle_irq_perbit(regs ,readl_relaxed(reg_base + GX_INTC_PEN31_00), 0);
+ ret |= handle_irq_perbit(regs ,readl_relaxed(reg_base + GX_INTC_PEN63_32), 32);
+ } while(ret);
+}
+
+static int __init
+gx_intc_init(struct device_node *node, struct device_node *parent)
+{
+ int ret;
+
+ ret = ck_intc_init_comm(node, parent);
+ if (ret)
+ return ret;
+
+ /* Initial enable reg to disable all interrupts */
+ writel_relaxed(0x0, reg_base + GX_INTC_NEN31_00);
+ writel_relaxed(0x0, reg_base + GX_INTC_NEN63_32);
+
+ /* Initial mask reg with all unmasked, becasue we only use enalbe reg */
+ writel_relaxed(0x0, reg_base + GX_INTC_NMASK31_00);
+ writel_relaxed(0x0, reg_base + GX_INTC_NMASK63_32);
+
+ setup_irq_channel(0x03020100, reg_base + GX_INTC_SOURCE);
+
+ ck_set_gc(node, reg_base, GX_INTC_NEN31_00, 0);
+ ck_set_gc(node, reg_base, GX_INTC_NEN63_32, 32);
+
+ set_handle_irq(gx_irq_handler);
+
+ return 0;
+}
+IRQCHIP_DECLARE(csky_gx6605s_intc, "csky,gx6605s-intc", gx_intc_init);
+
+/* C-SKY simple 64 irqs interrupt controller, dual-together could support 128 irqs */
+static void ck_irq_handler(struct pt_regs *regs)
+{
+ bool ret;
+
+ do {
+ /* handle 0 - 31 irqs */
+ ret = handle_irq_perbit(regs, readl_relaxed(reg_base + CK_INTC_PEN31_00), 0);
+ ret |= handle_irq_perbit(regs, readl_relaxed(reg_base + CK_INTC_PEN63_32), 32);
+
+ if (nr_irq == INTC_IRQS) continue;
+
+ /* handle 64 - 127 irqs */
+ ret |= handle_irq_perbit(regs,
+ readl_relaxed(reg_base + CK_INTC_PEN31_00 + CK_INTC_DUAL_BASE), 64);
+ ret |= handle_irq_perbit(regs,
+ readl_relaxed(reg_base + CK_INTC_PEN63_32 + CK_INTC_DUAL_BASE), 96);
+ } while(ret);
+}
+
+static int __init
+ck_intc_init(struct device_node *node, struct device_node *parent)
+{
+ int ret;
+
+ ret = ck_intc_init_comm(node, parent);
+ if (ret)
+ return ret;
+
+ /* Initial enable reg to disable all interrupts */
+ writel_relaxed(0, reg_base + CK_INTC_NEN31_00);
+ writel_relaxed(0, reg_base + CK_INTC_NEN63_32);
+
+ /* Enable irq intc */
+ writel_relaxed(BIT(31), reg_base + CK_INTC_ICR);
+
+ ck_set_gc(node, reg_base, CK_INTC_NEN31_00, 0);
+ ck_set_gc(node, reg_base, CK_INTC_NEN63_32, 32);
+
+ setup_irq_channel(0x00010203, reg_base + CK_INTC_SOURCE);
+
+ set_handle_irq(ck_irq_handler);
+
+ return 0;
+}
+IRQCHIP_DECLARE(ck_intc, "csky,apb-intc", ck_intc_init);
+
+static int __init
+ck_dual_intc_init(struct device_node *node, struct device_node *parent)
+{
+ int ret;
+
+ /* dual-apb-intc up to 128 irq sources*/
+ nr_irq = INTC_IRQS * 2;
+
+ ret = ck_intc_init(node, parent);
+ if (ret)
+ return ret;
+
+ /* Initial enable reg to disable all interrupts */
+ writel_relaxed(0, reg_base + CK_INTC_NEN31_00 + CK_INTC_DUAL_BASE);
+ writel_relaxed(0, reg_base + CK_INTC_NEN63_32 + CK_INTC_DUAL_BASE);
+
+ ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN31_00, 64);
+ ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN63_32, 96);
+
+ setup_irq_channel(0x00010203, reg_base + CK_INTC_SOURCE + CK_INTC_DUAL_BASE);
+
+ return 0;
+}
+IRQCHIP_DECLARE(ck_dual_intc, "csky,dual-apb-intc", ck_dual_intc_init);
--
2.7.4