irqchip: Add LPC32xx interrupt controller driver
authorVladimir Zapolskiy <vz@mleia.com>
Mon, 25 Apr 2016 01:00:38 +0000 (04:00 +0300)
committerMarc Zyngier <marc.zyngier@arm.com>
Wed, 11 May 2016 09:12:11 +0000 (10:12 +0100)
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 maintenance,
* SPARSE_IRQS option is supported.

Legacy LPC32xx interrupt controller driver was broken since commit
76ba59f8366f ("genirq: Add irq_domain-aware core IRQ handler"), which
requires a private interrupt handler, otherwise any SIC1 generated
interrupt (mapped to MIC hwirq 0) breaks the kernel with the message
"unexpected IRQ trap at vector 00".

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.

Fixes: 76ba59f8366f ("genirq: Add irq_domain-aware core IRQ handler")
Tested-by: Sylvain Lemieux <slemieux.tyco@gmail.com>
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
arch/arm/Kconfig
arch/arm/mach-lpc32xx/phy3250.c
drivers/irqchip/Makefile
drivers/irqchip/irq-lpc32xx.c [new file with mode: 0644]

index cdfa6c2b7626f3a761364ac072fc359b5f02592a..6684af91cb73ece6b50758130132adb9f56913a7 100644 (file)
@@ -531,6 +531,8 @@ config ARCH_LPC32XX
        select COMMON_CLK
        select CPU_ARM926T
        select GENERIC_CLOCKEVENTS
+       select MULTI_IRQ_HANDLER
+       select SPARSE_IRQ
        select USE_OF
        help
          Support for the NXP LPC32XX family of processors
index b2f9e226febeee970b0594c8be030a4838735e7c..f9209d091c4bf3f7b9bd187a4fb291bf3ae572d4 100644 (file)
@@ -206,7 +206,6 @@ 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,
 MACHINE_END
index 8cedf90605651418ef65f5381f1fe2dc6119f2fb..f828244b44c25bfadfbf44f3d70103cd4a1690f4 100644 (file)
@@ -7,6 +7,7 @@ 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-$(CONFIG_IRQ_MXS)                  += irq-mxs.o
 obj-$(CONFIG_ARCH_TEGRA)               += irq-tegra.o
diff --git a/drivers/irqchip/irq-lpc32xx.c b/drivers/irqchip/irq-lpc32xx.c
new file mode 100644 (file)
index 0000000..1034aeb
--- /dev/null
@@ -0,0 +1,238 @@
+/*
+ * Copyright 2015-2016 Vladimir Zapolskiy <vz@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/irqchip.h>
+#include <linux/irqchip/chained_irq.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 NR_LPC32XX_IC_IRQS             32
+
+struct lpc32xx_irq_chip {
+       void __iomem *base;
+       struct irq_domain *domain;
+       struct irq_chip chip;
+};
+
+static struct lpc32xx_irq_chip *lpc32xx_mic_irqc;
+
+static inline u32 lpc32xx_ic_read(struct lpc32xx_irq_chip *ic, u32 reg)
+{
+       return readl_relaxed(ic->base + reg);
+}
+
+static inline void lpc32xx_ic_write(struct lpc32xx_irq_chip *ic,
+                                   u32 reg, u32 val)
+{
+       writel_relaxed(val, ic->base + reg);
+}
+
+static void lpc32xx_irq_mask(struct irq_data *d)
+{
+       struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
+       u32 val, mask = BIT(d->hwirq);
+
+       val = lpc32xx_ic_read(ic, LPC32XX_INTC_MASK) & ~mask;
+       lpc32xx_ic_write(ic, LPC32XX_INTC_MASK, val);
+}
+
+static void lpc32xx_irq_unmask(struct irq_data *d)
+{
+       struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
+       u32 val, mask = BIT(d->hwirq);
+
+       val = lpc32xx_ic_read(ic, LPC32XX_INTC_MASK) | mask;
+       lpc32xx_ic_write(ic, LPC32XX_INTC_MASK, val);
+}
+
+static void lpc32xx_irq_ack(struct irq_data *d)
+{
+       struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
+       u32 mask = BIT(d->hwirq);
+
+       lpc32xx_ic_write(ic, LPC32XX_INTC_RAW, mask);
+}
+
+static int lpc32xx_irq_set_type(struct irq_data *d, unsigned int type)
+{
+       struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
+       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(ic, LPC32XX_INTC_POL);
+       if (high)
+               val |= mask;
+       else
+               val &= ~mask;
+       lpc32xx_ic_write(ic, LPC32XX_INTC_POL, val);
+
+       val = lpc32xx_ic_read(ic, 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(ic, LPC32XX_INTC_TYPE, val);
+
+       return 0;
+}
+
+static void __exception_irq_entry lpc32xx_handle_irq(struct pt_regs *regs)
+{
+       struct lpc32xx_irq_chip *ic = lpc32xx_mic_irqc;
+       u32 hwirq = lpc32xx_ic_read(ic, LPC32XX_INTC_STAT), irq;
+
+       while (hwirq) {
+               irq = __ffs(hwirq);
+               hwirq &= ~BIT(irq);
+               handle_domain_irq(lpc32xx_mic_irqc->domain, irq, regs);
+       }
+}
+
+static void lpc32xx_sic_handler(struct irq_desc *desc)
+{
+       struct lpc32xx_irq_chip *ic = irq_desc_get_handler_data(desc);
+       struct irq_chip *chip = irq_desc_get_chip(desc);
+       u32 hwirq = lpc32xx_ic_read(ic, LPC32XX_INTC_STAT), irq;
+
+       chained_irq_enter(chip, desc);
+
+       while (hwirq) {
+               irq = __ffs(hwirq);
+               hwirq &= ~BIT(irq);
+               generic_handle_irq(irq_find_mapping(ic->domain, irq));
+       }
+
+       chained_irq_exit(chip, desc);
+}
+
+static int lpc32xx_irq_domain_map(struct irq_domain *id, unsigned int virq,
+                                 irq_hw_number_t hw)
+{
+       struct lpc32xx_irq_chip *ic = id->host_data;
+
+       irq_set_chip_data(virq, ic);
+       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)
+{
+       struct lpc32xx_irq_chip *irqc;
+       bool is_mic = of_device_is_compatible(node, "nxp,lpc3220-mic");
+       const __be32 *reg = of_get_property(node, "reg", NULL);
+       u32 parent_irq, i, addr = reg ? be32_to_cpu(*reg) : 0;
+
+       irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
+       if (!irqc)
+               return -ENOMEM;
+
+       irqc->base = of_iomap(node, 0);
+       if (!irqc->base) {
+               pr_err("%s: unable to map registers\n", node->full_name);
+               kfree(irqc);
+               return -EINVAL;
+       }
+
+       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;
+       if (is_mic)
+               irqc->chip.name = kasprintf(GFP_KERNEL, "%08x.mic", addr);
+       else
+               irqc->chip.name = kasprintf(GFP_KERNEL, "%08x.sic", addr);
+
+       irqc->domain = irq_domain_add_linear(node, NR_LPC32XX_IC_IRQS,
+                                            &lpc32xx_irq_domain_ops, irqc);
+       if (!irqc->domain) {
+               pr_err("unable to add irq domain\n");
+               iounmap(irqc->base);
+               kfree(irqc->chip.name);
+               kfree(irqc);
+               return -ENODEV;
+       }
+
+       if (is_mic) {
+               lpc32xx_mic_irqc = irqc;
+               set_handle_irq(lpc32xx_handle_irq);
+       } else {
+               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);
+               }
+       }
+
+       lpc32xx_ic_write(irqc, LPC32XX_INTC_MASK, 0x00);
+       lpc32xx_ic_write(irqc, LPC32XX_INTC_POL,  0x00);
+       lpc32xx_ic_write(irqc, 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);