This commit adds support for the TS-4800 interrupt controller. This
controller is instantiated in a companion FPGA, and multiplex interrupts
for other FPGA IPs.
As this component is external to the SoC, the SoC might need to reserve
pins, so this controller is implemented as a platform driver and doesn't
use the IRQCHIP_DECLARE construct.
Signed-off-by: Damien Riegel <damien.riegel@xxxxxxxxxxxxxxxxxxxx>
---
drivers/irqchip/Kconfig | 6 ++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-ts4800.c | 156 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 163 insertions(+)
create mode 100644 drivers/irqchip/irq-ts4800.c
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 27b52c8..e734772 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -137,6 +137,12 @@ config TB10X_IRQC
select IRQ_DOMAIN
select GENERIC_IRQ_CHIP
+config TS4800_IRQ
+ tristate "TS-4800 IRQ controller"
+ select IRQ_DOMAIN
+ help
+ Support for the TS-4800 FPGA IRQ controller
+
config VERSATILE_FPGA_IRQ
bool
select IRQ_DOMAIN
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index bb3048f..ca9de01 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_ARCH_NSPIRE) += irq-zevio.o
obj-$(CONFIG_ARCH_VT8500) += irq-vt8500.o
obj-$(CONFIG_ST_IRQCHIP) += irq-st.o
obj-$(CONFIG_TB10X_IRQC) += irq-tb10x.o
+obj-$(CONFIG_TS4800_IRQ) += irq-ts4800.o
obj-$(CONFIG_XTENSA) += irq-xtensa-pic.o
obj-$(CONFIG_XTENSA_MX) += irq-xtensa-mx.o
obj-$(CONFIG_IRQ_CROSSBAR) += irq-crossbar.o
diff --git a/drivers/irqchip/irq-ts4800.c b/drivers/irqchip/irq-ts4800.c
new file mode 100644
index 0000000..f5a4d5b
--- /dev/null
+++ b/drivers/irqchip/irq-ts4800.c
@@ -0,0 +1,156 @@
+/*
+ * Multiplexed-IRQs driver for TS-4800's FPGA
+ *
+ * Copyright (c) 2015 - Savoir-faire Linux
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip.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/platform_device.h>
+
+#define IRQ_MASK 0x4
+#define IRQ_STATUS 0x8
+
+struct ts4800_irq_data {
+ void __iomem *base;
+ struct irq_domain *domain;
+ struct irq_chip irq_chip;
+};
+
+static void ts4800_irq_mask(struct irq_data *d)
+{
+ struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d);
+ u16 mask = 1 << d->hwirq;
+ u16 reg = readw(data->base + IRQ_MASK);
+
+ writew(reg | mask, data->base + IRQ_MASK);
+}
+
+static void ts4800_irq_unmask(struct irq_data *d)
+{
+ struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d);
+ u16 mask = 1 << d->hwirq;
+ u16 reg = readw(data->base + IRQ_MASK);
+
+ writew(reg & ~mask, data->base + IRQ_MASK);
+}
+
+static int ts4800_irqdomain_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ struct ts4800_irq_data *data = d->host_data;
+
+ irq_set_chip_and_handler(irq, &data->irq_chip, handle_simple_irq);
+ irq_set_chip_data(irq, data);
+ irq_set_noprobe(irq);
+
+ return 0;
+}
+
+struct irq_domain_ops ts4800_ic_ops = {
+ .map = ts4800_irqdomain_map,
+ .xlate = irq_domain_xlate_onecell,
+};
+
+static void ts4800_ic_chained_handle_irq(struct irq_desc *desc)
+{
+ struct ts4800_irq_data *data = irq_desc_get_handler_data(desc);
+ u16 status = readw(data->base + IRQ_STATUS);
+
+ if (unlikely(status == 0)) {
+ handle_bad_irq(desc);
+ return;
+ }
+
+ do {
+ unsigned int bit = __ffs(status);
+ int irq = irq_find_mapping(data->domain, bit);
+
+ status &= ~(1 << bit);
+ generic_handle_irq(irq);
+ } while (status);
+}
+
+static int ts4800_ic_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct ts4800_irq_data *data;
+ struct irq_chip *irq_chip;
+ struct resource *res;
+ int parent_irq;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ data->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(data->base))
+ return PTR_ERR(data->base);
+
+ writew(0xFFFF, data->base + IRQ_MASK);
+
+ parent_irq = irq_of_parse_and_map(node, 0);
+ if (!parent_irq) {
+ dev_err(&pdev->dev, "failed to get parent IRQ\n");
+ return -EINVAL;
+ }
+
+ irq_chip = &data->irq_chip;
+ irq_chip->name = dev_name(&pdev->dev);
+ irq_chip->irq_mask = ts4800_irq_mask;
+ irq_chip->irq_unmask = ts4800_irq_unmask;
+
+ data->domain = irq_domain_add_linear(node, 8, &ts4800_ic_ops, data);
+ if (!data->domain) {
+ dev_err(&pdev->dev, "cannot add IRQ domain\n");
+ return -ENOMEM;
+ }
+
+ irq_set_chained_handler_and_data(parent_irq,
+ ts4800_ic_chained_handle_irq, data);
+
+ platform_set_drvdata(pdev, data);
+
+ return 0;
+}
+
+static int ts4800_ic_remove(struct platform_device *pdev)
+{
+ struct ts4800_irq_data *data = platform_get_drvdata(pdev);
+
+ irq_domain_remove(data->domain);
+
+ return 0;
+}
+
+static const struct of_device_id ts4800_ic_of_match[] = {
+ { .compatible = "technologic,ts4800-irqc", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ts4800_ic_of_match);
+
+static struct platform_driver ts4800_ic_driver = {
+ .probe = ts4800_ic_probe,
+ .remove = ts4800_ic_remove,
+ .driver = {
+ .name = "ts4800-irqc",
+ .of_match_table = ts4800_ic_of_match,
+ },
+};
+module_platform_driver(ts4800_ic_driver);
+
+MODULE_AUTHOR("Damien Riegel <damien.riegel@xxxxxxxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:ts4800_irqc");
--
2.5.0
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