This irq mux driver is derived from the RTD1295 vendor DT and assumes a
linear mapping between intr_en and intr_status registers.
Code for RTD119x indicates this may not always be the case (i2c_3).
Based in part on QNAP's arch/arm/mach-rtk119x/rtk_irq_mux.c code.
Signed-off-by: Andreas Färber <afaer...@suse.de>
---
v1 -> v2:
* Renamed struct fields to avoid ambiguity (Marc)
* Refactored offset lookup to avoid per-compatible init functions
* Inserted white lines to clarify balanced locking (Marc)
* Dropped forwarding of set_affinity to GIC (Marc)
* Added spinlocks for consistency (Marc)
* Limited initialization quirk to iso mux
* Fixed spinlock initialization (Andrew)
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-rtd119x-mux.c | 204 ++++++++++++++++++++++++++++++++++++++
2 files changed, 205 insertions(+)
create mode 100644 drivers/irqchip/irq-rtd119x-mux.c
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index e88d856cc09c..46202a0b7d96 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -78,3 +78,4 @@ obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o
obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o irq-aspeed-i2c-ic.o
obj-$(CONFIG_STM32_EXTI) += irq-stm32-exti.o
obj-$(CONFIG_QCOM_IRQ_COMBINER) += qcom-irq-combiner.o
+obj-$(CONFIG_ARCH_REALTEK) += irq-rtd119x-mux.o
diff --git a/drivers/irqchip/irq-rtd119x-mux.c
b/drivers/irqchip/irq-rtd119x-mux.c
new file mode 100644
index 000000000000..65d22e163bef
--- /dev/null
+++ b/drivers/irqchip/irq-rtd119x-mux.c
@@ -0,0 +1,204 @@
+/*
+ * Realtek RTD129x IRQ mux
+ *
+ * Copyright (c) 2017 Andreas Färber
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <linux/io.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+
+struct rtd119x_irq_mux_info {
+ unsigned intr_status_offset;
+ unsigned intr_en_offset;
+};
+
+struct rtd119x_irq_mux_data {
+ void __iomem *intr_status;
+ void __iomem *intr_en;
+ int irq;
+ struct irq_domain *domain;
+ spinlock_t lock;
+};
+
+static void rtd119x_mux_irq_handle(struct irq_desc *desc)
+{
+ struct rtd119x_irq_mux_data *data = irq_desc_get_handler_data(desc);
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ u32 intr_en, intr_status, status;
+ int ret;
+
+ chained_irq_enter(chip, desc);
+
+ spin_lock(&data->lock);
+ intr_en = readl(data->intr_en);
+ intr_status = readl(data->intr_status);
+ spin_unlock(&data->lock);
+
+ status = intr_status & intr_en;
+ if (status != 0) {
+ unsigned irq = __ffs(status);
+ ret = generic_handle_irq(irq_find_mapping(data->domain, irq));
+ if (ret == 0) {
+ spin_lock(&data->lock);
+
+ intr_status = readl(data->intr_status);
+ intr_status |= BIT(irq - 1);
+ writel(intr_status, data->intr_status);
+
+ spin_unlock(&data->lock);
+ }
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+static void rtd119x_mux_mask_irq(struct irq_data *data)
+{
+ struct rtd119x_irq_mux_data *mux_data =
irq_data_get_irq_chip_data(data);
+ u32 intr_status;
+
+ spin_lock(&mux_data->lock);
+
+ intr_status = readl(mux_data->intr_status);
+ intr_status |= BIT(data->hwirq);
+ writel(intr_status, mux_data->intr_status);
+
+ spin_unlock(&mux_data->lock);
+}
+
+static void rtd119x_mux_unmask_irq(struct irq_data *data)
+{
+ struct rtd119x_irq_mux_data *mux_data =
irq_data_get_irq_chip_data(data);
+ u32 intr_en;
+
+ spin_lock(&mux_data->lock);
+
+ intr_en = readl(mux_data->intr_en);
+ intr_en |= BIT(data->hwirq);
+ writel(intr_en, mux_data->intr_en);
+
+ spin_unlock(&mux_data->lock);
+}
+
+static int rtd119x_mux_set_affinity(struct irq_data *d,
+ const struct cpumask *mask_val, bool force)
+{
+ /* Forwarding the affinity to the parent would affect all 32
interrupts. */
+ return -EINVAL;
+}
+
+static struct irq_chip rtd119x_mux_irq_chip = {
+ .name = "rtd119x-mux",
+ .irq_mask = rtd119x_mux_mask_irq,
+ .irq_unmask = rtd119x_mux_unmask_irq,
+ .irq_set_affinity = rtd119x_mux_set_affinity,
+};
+
+static int rtd119x_mux_irq_domain_map(struct irq_domain *d,
+ unsigned int irq, irq_hw_number_t hw)
+{
+ struct rtd119x_irq_mux_data *data = d->host_data;
+
+ irq_set_chip_and_handler(irq, &rtd119x_mux_irq_chip, handle_level_irq);
+ irq_set_chip_data(irq, data);
+ irq_set_probe(irq);
+
+ return 0;
+}
+
+static struct irq_domain_ops rtd119x_mux_irq_domain_ops = {
+ .xlate = irq_domain_xlate_onecell,
+ .map = rtd119x_mux_irq_domain_map,
+};
+
+static const struct rtd119x_irq_mux_info rtd1295_iso_irq_mux_info = {
+ .intr_status_offset = 0x0,
+ .intr_en_offset = 0x40,
+};
+
+static const struct rtd119x_irq_mux_info rtd1295_irq_mux_info = {
+ .intr_status_offset = 0xc,
+ .intr_en_offset = 0x80,
+};
+
+static const struct of_device_id rtd1295_irq_mux_dt_matches[] = {
+ {
+ .compatible = "realtek,rtd1295-iso-irq-mux",
+ .data = &rtd1295_iso_irq_mux_info,
+ }, {
+ .compatible = "realtek,rtd1295-irq-mux",
+ .data = &rtd1295_irq_mux_info,
+ }, {
+ }
+};
+
+static int __init rtd119x_irq_mux_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct rtd119x_irq_mux_data *data;
+ const struct of_device_id *match;
+ const struct rtd119x_irq_mux_info *info;
+ void __iomem *base;
+ u32 val;
+
+ match = of_match_node(rtd1295_irq_mux_dt_matches, node);
+ if (!match)
+ return -EINVAL;
+
+ info = match->data;
+ if (!info)
+ return -EINVAL;
+
+ base = of_iomap(node, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->intr_status = base + info->intr_status_offset;
+ data->intr_en = base + info->intr_en_offset;
+
+ data->irq = irq_of_parse_and_map(node, 0);
+ if (data->irq <= 0) {
+ kfree(data);
+ return -EINVAL;
+ }
+
+ spin_lock_init(&data->lock);
+
+ data->domain = irq_domain_add_linear(node, 32,
+ &rtd119x_mux_irq_domain_ops, data);
+ if (!data->domain) {
+ kfree(data);
+ return -ENOMEM;
+ }
+
+ if (of_device_is_compatible(node, "realtek,rtd1295-iso-irq-mux")) {
+ const int uart0_irq = 2;
+
+ spin_lock(&data->lock);
+
+ val = readl(data->intr_en);
+ val &= ~BIT(uart0_irq);
+ writel(val, data->intr_en);
+
+ writel(BIT(uart0_irq), data->intr_status);
+
+ spin_unlock(&data->lock);
+ }
+
+ irq_set_chained_handler_and_data(data->irq, rtd119x_mux_irq_handle,
data);
+
+ return 0;
+}
+IRQCHIP_DECLARE(rtd1295_iso_mux, "realtek,rtd1295-iso-irq-mux",
rtd119x_irq_mux_init);
+IRQCHIP_DECLARE(rtd1295_mux, "realtek,rtd1295-irq-mux", rtd119x_irq_mux_init);
--
2.12.3
