[PATCH 03/22 v2] irqchip: add a driver for Cortina Gemini
Linus Walleij
linus.walleij at linaro.org
Sat Jan 28 13:15:25 PST 2017
As a part of transitioning the Gemini platform to device tree we
create this clean, device-tree-only irqchip driver.
Cc: Janos Laube <janos.dev at gmail.com>
Cc: Paulius Zaleckas <paulius.zaleckas at gmail.com>
Cc: Hans Ulli Kroll <ulli.kroll at googlemail.com>
Cc: Florian Fainelli <f.fainelli at gmail.com>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
ChangeLog v1->v2:
- Do not call irq_create_mapping() on all hwirqs at probe: this
will happen automatically when looking up the IRQs from the
device tree and is not needed.
irqchip maintainers: please just apply this when you feel pleased
with it. These portions are functionally orthogonal to the series,
it is just in a series for context.
---
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-gemini.c | 185 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 186 insertions(+)
create mode 100644 drivers/irqchip/irq-gemini.c
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 0e55d94065bf..ab1752f50104 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_ATH79) += irq-ath79-misc.o
obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2835.o
obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2836.o
obj-$(CONFIG_ARCH_EXYNOS) += exynos-combiner.o
+obj-$(CONFIG_ARCH_GEMINI) += irq-gemini.o
obj-$(CONFIG_ARCH_HIP04) += irq-hip04.o
obj-$(CONFIG_ARCH_LPC32XX) += irq-lpc32xx.o
obj-$(CONFIG_ARCH_MMP) += irq-mmp.o
diff --git a/drivers/irqchip/irq-gemini.c b/drivers/irqchip/irq-gemini.c
new file mode 100644
index 000000000000..110c83d5106a
--- /dev/null
+++ b/drivers/irqchip/irq-gemini.c
@@ -0,0 +1,185 @@
+/*
+ * irqchip for the Cortina Systems Gemini
+ * Copyright (C) 2017 Linus Walleij <linus.walleij at linaro.org>
+ *
+ * Based on arch/arm/mach-gemini/irq.c
+ * Copyright (C) 2001-2006 Storlink, Corp.
+ * Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas at teltonika.lt>
+ */
+#include <linux/bitops.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/versatile-fpga.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/cpu.h>
+
+#include <asm/exception.h>
+#include <asm/mach/irq.h>
+
+#define GEMINI_NUM_IRQS 32
+
+#define IRQ_SOURCE(base_addr) (base_addr + 0x00)
+#define IRQ_MASK(base_addr) (base_addr + 0x04)
+#define IRQ_CLEAR(base_addr) (base_addr + 0x08)
+#define IRQ_TMODE(base_addr) (base_addr + 0x0C)
+#define IRQ_TLEVEL(base_addr) (base_addr + 0x10)
+#define IRQ_STATUS(base_addr) (base_addr + 0x14)
+#define FIQ_SOURCE(base_addr) (base_addr + 0x20)
+#define FIQ_MASK(base_addr) (base_addr + 0x24)
+#define FIQ_CLEAR(base_addr) (base_addr + 0x28)
+#define FIQ_TMODE(base_addr) (base_addr + 0x2C)
+#define FIQ_LEVEL(base_addr) (base_addr + 0x30)
+#define FIQ_STATUS(base_addr) (base_addr + 0x34)
+
+/**
+ * struct gemini_irq_data - irq data container for the Gemini IRQ controller
+ * @base: memory offset in virtual memory
+ * @chip: chip container for this instance
+ * @domain: IRQ domain for this instance
+ */
+struct gemini_irq_data {
+ void __iomem *base;
+ struct irq_chip chip;
+ struct irq_domain *domain;
+};
+
+static void gemini_irq_mask(struct irq_data *d)
+{
+ struct gemini_irq_data *g = irq_data_get_irq_chip_data(d);
+ unsigned int mask;
+
+ mask = readl(IRQ_MASK(g->base));
+ mask &= ~BIT(irqd_to_hwirq(d));
+ writel(mask, IRQ_MASK(g->base));
+}
+
+static void gemini_irq_unmask(struct irq_data *d)
+{
+ struct gemini_irq_data *g = irq_data_get_irq_chip_data(d);
+ unsigned int mask;
+
+ mask = readl(IRQ_MASK(g->base));
+ mask |= BIT(irqd_to_hwirq(d));
+ writel(mask, IRQ_MASK(g->base));
+}
+
+static void gemini_irq_ack(struct irq_data *d)
+{
+ struct gemini_irq_data *g = irq_data_get_irq_chip_data(d);
+
+ writel(BIT(irqd_to_hwirq(d)), IRQ_CLEAR(g->base));
+}
+
+static int gemini_irq_set_type(struct irq_data *d, unsigned int trigger)
+{
+ struct gemini_irq_data *g = irq_data_get_irq_chip_data(d);
+ int offset = irqd_to_hwirq(d);
+ u32 mode, level;
+
+ /*
+ * TODO: Probably these registers can handle low level and
+ * falling edges too.
+ */
+ mode = readl(IRQ_TMODE(g->base));
+ level = readl(IRQ_TLEVEL(g->base));
+
+ if (trigger & (IRQ_TYPE_LEVEL_HIGH)) {
+ irq_set_handler_locked(d, handle_level_irq);
+ /* Disable edge detection */
+ mode &= ~BIT(offset);
+ level &= ~BIT(offset);
+ } else if (trigger & IRQ_TYPE_EDGE_RISING) {
+ irq_set_handler_locked(d, handle_edge_irq);
+ mode |= BIT(offset);
+ level |= BIT(offset);
+ } else {
+ irq_set_handler_locked(d, handle_bad_irq);
+ pr_warn("GEMINI IRQ: no supported trigger selected for line %d\n",
+ offset);
+ }
+
+ writel(mode, IRQ_TMODE(g->base));
+ writel(level, IRQ_TLEVEL(g->base));
+
+ return 0;
+}
+
+static struct irq_chip gemini_irq_chip = {
+ .name = "GEMINI",
+ .irq_ack = gemini_irq_ack,
+ .irq_mask = gemini_irq_mask,
+ .irq_unmask = gemini_irq_unmask,
+ .irq_set_type = gemini_irq_set_type,
+};
+
+/* Local static for the IRQ entry call */
+static struct gemini_irq_data girq;
+
+asmlinkage void __exception_irq_entry gemini_irqchip_handle_irq(struct pt_regs *regs)
+{
+ struct gemini_irq_data *g = &girq;
+ int irq;
+ u32 status;
+
+ while ((status = readl(IRQ_STATUS(g->base)))) {
+ irq = ffs(status) - 1;
+ handle_domain_irq(g->domain, irq, regs);
+ }
+}
+
+static int gemini_irqdomain_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ struct gemini_irq_data *g = d->host_data;
+
+ irq_set_chip_data(irq, g);
+ /* All IRQs should set up their type, flags as bad by default */
+ irq_set_chip_and_handler(irq, &gemini_irq_chip, handle_bad_irq);
+ irq_set_probe(irq);
+
+ return 0;
+}
+
+static void gemini_irqdomain_unmap(struct irq_domain *d, unsigned int irq)
+{
+ irq_set_chip_and_handler(irq, NULL, NULL);
+ irq_set_chip_data(irq, NULL);
+}
+
+static const struct irq_domain_ops gemini_irqdomain_ops = {
+ .map = gemini_irqdomain_map,
+ .unmap = gemini_irqdomain_unmap,
+ .xlate = irq_domain_xlate_onetwocell,
+};
+
+int __init gemini_of_init_irq(struct device_node *node,
+ struct device_node *parent)
+{
+ struct gemini_irq_data *g = &girq;
+
+ /*
+ * Disable the idle handler by default since it is buggy
+ * For more info see arch/arm/mach-gemini/idle.c
+ */
+ cpu_idle_poll_ctrl(true);
+
+ g->base = of_iomap(node, 0);
+ WARN(!g->base, "unable to map gemini irq registers\n");
+
+ /* Disable all interrupts */
+ writel(0, IRQ_MASK(g->base));
+ writel(0, FIQ_MASK(g->base));
+
+ g->domain = irq_domain_add_simple(node, GEMINI_NUM_IRQS, 0,
+ &gemini_irqdomain_ops, g);
+ set_handle_irq(gemini_irqchip_handle_irq);
+
+ return 0;
+}
+IRQCHIP_DECLARE(gemini, "cortina,gemini-interrupt-controller",
+ gemini_of_init_irq);
--
2.9.3
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