[PATCH 08/10] irqchip: add LPC32xx interrupt controller driver
Vladimir Zapolskiy
vz at mleia.com
Thu Nov 19 17:28:43 PST 2015
The change adds improved support of NXP LPC32xx MIC, SIC1 and SIC2
interrupt controllers.
This is a list of new features in comparison to the legacy driver:
* irq types are taken from device tree settings, no more need to
hardcode them,
* old driver is based on irq_domain_add_legacy, which causes problems
with handling MIC hardware interrupt 0 produced by SIC1,
* there is one driver for MIC, SIC1 and SIC2, no more need to handle
them separately, e.g. have two separate handlers for SIC1 and SIC2,
* the driver does not have any dependencies on hardcoded register
offsets,
* the driver is much simpler for comprehension and more maintainable,
* SPARSE_IRQS option is supported.
The change disables compilation of a legacy driver found at
arch/arm/mach-lpc32xx/irq.c, the file will be removed in a separate
commit.
Signed-off-by: Vladimir Zapolskiy <vz at mleia.com>
---
arch/arm/Kconfig | 2 +
arch/arm/mach-lpc32xx/Makefile | 2 +-
arch/arm/mach-lpc32xx/phy3250.c | 1 -
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-lpc32xx.c | 227 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 231 insertions(+), 2 deletions(-)
create mode 100644 drivers/irqchip/irq-lpc32xx.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 5cc11f1..1f2c03f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -597,6 +597,8 @@ config ARCH_LPC32XX
select CPU_ARM926T
select GENERIC_CLOCKEVENTS
select HAVE_IDE
+ select MULTI_IRQ_HANDLER
+ select SPARSE_IRQ
select USE_OF
help
Support for the NXP LPC32XX family of processors
diff --git a/arch/arm/mach-lpc32xx/Makefile b/arch/arm/mach-lpc32xx/Makefile
index b1023c0..2a28f645 100644
--- a/arch/arm/mach-lpc32xx/Makefile
+++ b/arch/arm/mach-lpc32xx/Makefile
@@ -2,6 +2,6 @@
# Makefile for the linux kernel.
#
-obj-y := irq.o common.o serial.o
+obj-y := common.o serial.o
obj-y += pm.o suspend.o wakeup.o
obj-y += phy3250.o
diff --git a/arch/arm/mach-lpc32xx/phy3250.c b/arch/arm/mach-lpc32xx/phy3250.c
index 60f3392..92e8574 100644
--- a/arch/arm/mach-lpc32xx/phy3250.c
+++ b/arch/arm/mach-lpc32xx/phy3250.c
@@ -259,7 +259,6 @@ static const char *const lpc32xx_dt_compat[] __initconst = {
DT_MACHINE_START(LPC32XX_DT, "LPC32XX SoC (Flattened Device Tree)")
.atag_offset = 0x100,
.map_io = lpc32xx_map_io,
- .init_irq = lpc32xx_init_irq,
.init_machine = lpc3250_machine_init,
.dt_compat = lpc32xx_dt_compat,
.restart = lpc23xx_restart,
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 177f78f..21008a6 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2835.o
obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2836.o
obj-$(CONFIG_ARCH_EXYNOS) += exynos-combiner.o
obj-$(CONFIG_ARCH_HIP04) += irq-hip04.o
+obj-$(CONFIG_ARCH_LPC32XX) += irq-lpc32xx.o
obj-$(CONFIG_ARCH_MMP) += irq-mmp.o
obj-$(CONFIG_ARCH_MVEBU) += irq-armada-370-xp.o
obj-$(CONFIG_IRQ_MXS) += irq-mxs.o
diff --git a/drivers/irqchip/irq-lpc32xx.c b/drivers/irqchip/irq-lpc32xx.c
new file mode 100644
index 0000000..fcf281b
--- /dev/null
+++ b/drivers/irqchip/irq-lpc32xx.c
@@ -0,0 +1,227 @@
+/*
+ * Copyright 2015 Vladimir Zapolskiy <vz at mleia.com>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+#include <asm/exception.h>
+
+#define LPC32XX_INTC_MASK 0x00
+#define LPC32XX_INTC_RAW 0x04
+#define LPC32XX_INTC_STAT 0x08
+#define LPC32XX_INTC_POL 0x0C
+#define LPC32XX_INTC_TYPE 0x10
+#define LPC32XX_INTC_FIQ 0x14
+
+#define IRQS_PER_CONTROLLER 32
+
+struct lpc32xx_irq_chip {
+ void __iomem *base;
+ struct irq_domain *domain;
+ struct irq_chip chip;
+};
+
+static struct lpc32xx_irq_chip *lpc32xx_mic_data;
+
+static inline u32 lpc32xx_ic_read(struct irq_domain *id, u32 reg)
+{
+ struct lpc32xx_irq_chip *ic = (struct lpc32xx_irq_chip *)id->host_data;
+
+ return readl(ic->base + reg);
+}
+
+static inline void lpc32xx_ic_write(struct irq_domain *id, u32 reg, u32 val)
+{
+ struct lpc32xx_irq_chip *ic = (struct lpc32xx_irq_chip *)id->host_data;
+
+ writel(val, ic->base + reg);
+}
+
+static void lpc32xx_irq_mask(struct irq_data *d)
+{
+ u32 val, mask = BIT(d->hwirq);
+
+ val = lpc32xx_ic_read(d->domain, LPC32XX_INTC_MASK) & ~mask;
+ lpc32xx_ic_write(d->domain, LPC32XX_INTC_MASK, val);
+}
+
+static void lpc32xx_irq_unmask(struct irq_data *d)
+{
+ u32 val, mask = BIT(d->hwirq);
+
+ val = lpc32xx_ic_read(d->domain, LPC32XX_INTC_MASK) | mask;
+ lpc32xx_ic_write(d->domain, LPC32XX_INTC_MASK, val);
+}
+
+static void lpc32xx_irq_ack(struct irq_data *d)
+{
+ u32 mask = BIT(d->hwirq);
+
+ lpc32xx_ic_write(d->domain, LPC32XX_INTC_RAW, mask);
+}
+
+static int lpc32xx_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ struct irq_domain *domain = d->domain;
+ u32 val, mask = BIT(d->hwirq);
+ bool high, edge;
+
+ switch (type) {
+ case IRQ_TYPE_EDGE_RISING:
+ edge = true;
+ high = true;
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ edge = true;
+ high = false;
+ break;
+ case IRQ_TYPE_LEVEL_HIGH:
+ edge = false;
+ high = true;
+ break;
+ case IRQ_TYPE_LEVEL_LOW:
+ edge = false;
+ high = false;
+ break;
+ default:
+ pr_info("unsupported irq type %d\n", type);
+ return -EINVAL;
+ }
+
+ irqd_set_trigger_type(d, type);
+
+ val = lpc32xx_ic_read(domain, LPC32XX_INTC_POL);
+ if (high)
+ val |= mask;
+ else
+ val &= ~mask;
+ lpc32xx_ic_write(domain, LPC32XX_INTC_POL, val);
+
+ val = lpc32xx_ic_read(domain, LPC32XX_INTC_TYPE);
+ if (edge) {
+ val |= mask;
+ irq_set_handler_locked(d, handle_edge_irq);
+ } else {
+ val &= ~mask;
+ irq_set_handler_locked(d, handle_level_irq);
+ }
+ lpc32xx_ic_write(domain, LPC32XX_INTC_TYPE, val);
+
+ return 0;
+}
+
+static void __exception_irq_entry lpc32xx_handle_irq(struct pt_regs *regs)
+{
+ u32 hwirq;
+
+ do {
+ hwirq = lpc32xx_ic_read(lpc32xx_mic_data->domain,
+ LPC32XX_INTC_STAT);
+ if (hwirq)
+ handle_domain_irq(lpc32xx_mic_data->domain,
+ ffs(hwirq) - 1, regs);
+ } while (hwirq);
+}
+
+static void lpc32xx_sic_handler(struct irq_desc *desc)
+{
+ struct lpc32xx_irq_chip *ic = irq_desc_get_handler_data(desc);
+ struct irq_domain *domain = ic->domain;
+ u32 hwirq;
+
+ do {
+ hwirq = lpc32xx_ic_read(domain, LPC32XX_INTC_STAT);
+ if (hwirq)
+ generic_handle_irq(irq_find_mapping(domain,
+ ffs(hwirq) - 1));
+ } while (hwirq);
+}
+
+static int lpc32xx_irq_domain_map(struct irq_domain *id, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ struct lpc32xx_irq_chip *ic = (struct lpc32xx_irq_chip *)id->host_data;
+
+ irq_set_chip_and_handler(virq, &ic->chip, handle_level_irq);
+ irq_set_status_flags(virq, IRQ_LEVEL);
+ irq_set_noprobe(virq);
+
+ return 0;
+}
+
+static void lpc32xx_irq_domain_unmap(struct irq_domain *id, unsigned int virq)
+{
+ irq_set_chip_and_handler(virq, NULL, NULL);
+}
+
+static const struct irq_domain_ops lpc32xx_irq_domain_ops = {
+ .map = lpc32xx_irq_domain_map,
+ .unmap = lpc32xx_irq_domain_unmap,
+ .xlate = irq_domain_xlate_twocell,
+};
+
+static int __init lpc32xx_of_ic_init(struct device_node *node,
+ struct device_node *parent)
+{
+ int parent_irq, i;
+ struct lpc32xx_irq_chip *irqc;
+
+ irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
+ if (!irqc)
+ return -ENOMEM;
+
+ irqc->chip.irq_ack = lpc32xx_irq_ack;
+ irqc->chip.irq_mask = lpc32xx_irq_mask;
+ irqc->chip.irq_unmask = lpc32xx_irq_unmask;
+ irqc->chip.irq_set_type = lpc32xx_irq_set_type;
+ irqc->chip.name = of_get_property(node, "interrupt-controller-name",
+ NULL);
+
+ irqc->base = of_iomap(node, 0);
+ if (!irqc->base) {
+ pr_err("%s: unable to map registers\n", node->full_name);
+ return -EINVAL;
+ }
+
+ irqc->domain = irq_domain_add_linear(node, IRQS_PER_CONTROLLER,
+ &lpc32xx_irq_domain_ops, irqc);
+ if (!irqc->domain) {
+ pr_err("unable to add irq domain\n");
+ iounmap(irqc->base);
+ return -ENODEV;
+ }
+
+ for (i = 0; i < of_irq_count(node); i++) {
+ parent_irq = irq_of_parse_and_map(node, i);
+ if (parent_irq)
+ irq_set_chained_handler_and_data(parent_irq,
+ lpc32xx_sic_handler, irqc);
+ }
+
+ if (of_device_is_compatible(node, "nxp,lpc3220-mic")) {
+ lpc32xx_mic_data = irqc;
+ set_handle_irq(lpc32xx_handle_irq);
+ }
+
+ lpc32xx_ic_write(irqc->domain, LPC32XX_INTC_MASK, 0x00);
+ lpc32xx_ic_write(irqc->domain, LPC32XX_INTC_POL, 0x00);
+ lpc32xx_ic_write(irqc->domain, LPC32XX_INTC_TYPE, 0x00);
+
+ return 0;
+}
+IRQCHIP_DECLARE(nxp_lpc32xx_mic, "nxp,lpc3220-mic", lpc32xx_of_ic_init);
+IRQCHIP_DECLARE(nxp_lpc32xx_sic, "nxp,lpc3220-sic", lpc32xx_of_ic_init);
--
2.1.4
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