Hi Marc,

Thanks for the quick review!

On Mon, Nov 19, 2018 at 05:36:49PM +0000, Marc Zyngier wrote:

Manivannan,

On 19/11/2018 17:09, Manivannan Sadhasivam wrote:

quoted

Add interrupt driver for RDA Micro RDA8810PL SoC.

Signed-off-by: Andreas F?rber <afaerber@suse.de>
Signed-off-by: Manivannan Sadhasivam <redacted>
---
 arch/arm/mach-rda/Kconfig      |   1 +
 drivers/irqchip/Kconfig        |   4 ++
 drivers/irqchip/Makefile       |   1 +
 drivers/irqchip/irq-rda-intc.c | 116 +++++++++++++++++++++++++++++++++
 4 files changed, 122 insertions(+)
 create mode 100644 drivers/irqchip/irq-rda-intc.c

diff --git a/arch/arm/mach-rda/Kconfig b/arch/arm/mach-rda/Kconfig
index dafab78d7aab..29012bc68ca4 100644
--- a/arch/arm/mach-rda/Kconfig
+++ b/arch/arm/mach-rda/Kconfig

@@ -3,5 +3,6 @@ menuconfig ARCH_RDA
 	depends on ARCH_MULTI_V7
 	select COMMON_CLK
 	select GENERIC_IRQ_CHIP
+	select RDA_INTC
 	help
 	  This enables support for the RDA Micro 8810PL SoC family.

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 51a5ef0e96ed..9d54645870ad 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig

@@ -195,6 +195,10 @@ config JCORE_AIC
 	help
 	  Support for the J-Core integrated AIC.
 
+config RDA_INTC
+	bool
+	select IRQ_DOMAIN
+
 config RENESAS_INTC_IRQPIN
 	bool
 	select IRQ_DOMAIN

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 794c13d3ac3d..417108027e40 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile

@@ -43,6 +43,7 @@ obj-$(CONFIG_IMGPDC_IRQ)		+= irq-imgpdc.o
 obj-$(CONFIG_IRQ_MIPS_CPU)		+= irq-mips-cpu.o
 obj-$(CONFIG_SIRF_IRQ)			+= irq-sirfsoc.o
 obj-$(CONFIG_JCORE_AIC)			+= irq-jcore-aic.o
+obj-$(CONFIG_RDA_INTC)			+= irq-rda-intc.o
 obj-$(CONFIG_RENESAS_INTC_IRQPIN)	+= irq-renesas-intc-irqpin.o
 obj-$(CONFIG_RENESAS_IRQC)		+= irq-renesas-irqc.o
 obj-$(CONFIG_VERSATILE_FPGA_IRQ)	+= irq-versatile-fpga.o

diff --git a/drivers/irqchip/irq-rda-intc.c b/drivers/irqchip/irq-rda-intc.c
new file mode 100644
index 000000000000..89be55a11823
--- /dev/null
+++ b/drivers/irqchip/irq-rda-intc.c

@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RDA8810PL SoC irqchip driver
+ *
+ * Copyright RDA Microelectronics Company Limited
+ * Copyright (c) 2017 Andreas F?rber
+ * Copyright (c) 2018 Manivannan Sadhasivam
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+
+#include <asm/irq.h>
+#include <asm/exception.h>
+
+#define RDA_INTC_FINALSTATUS	0x00
+#define RDA_INTC_STATUS		0x04
+#define RDA_INTC_MASK_SET	0x08
+#define RDA_INTC_MASK_CLR	0x0c
+#define RDA_INTC_WAKEUP_MASK	0x18
+#define RDA_INTC_CPU_SLEEP	0x1c
+
+#define RDA_IRQ_MASK_ALL	0xFFFFFFFF
+
+#define RDA_NR_IRQS 32
+
+void __iomem *base;

Should be static?

Ack.

quoted

+
+static void rda_intc_mask_irq(struct irq_data *d)
+{
+	void __iomem *base = (void __iomem *)irq_data_get_irq_chip_data(d);

Aliases with the above. Please choose whether you want a global or a
per-interrupt base.

My bad. I wanted to have a global interrupt base for rda_handle_irq.
Will remove the per interrupt base.

quoted

+
+	writel(BIT(d->hwirq), base + RDA_INTC_MASK_CLR);

writel_relaxed()

Ack.

quoted

+}
+
+static void rda_intc_unmask_irq(struct irq_data *d)
+{
+	void __iomem *base = (void __iomem *)irq_data_get_irq_chip_data(d);
+
+	writel(BIT(d->hwirq), base + RDA_INTC_MASK_SET);

Same here.

Ack.

quoted

+}
+
+static int rda_intc_set_type(struct irq_data *data, unsigned int flow_type)
+{
+	if (flow_type & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING))
+		irq_set_handler(data->irq, handle_edge_irq);
+	if (flow_type & (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW))
+		irq_set_handler(data->irq, handle_level_irq);

So you don't need to set anything in your interrupt controller for this
to switch between level and edge? That'd be a first...

Interrupt controller can only handle level triggered interrupts. Should
I just remove irq_set_type callback itself?

quoted

+
+	return 0;
+}
+
+struct irq_domain *rda_irq_domain;

static?

Ack.

quoted

+
+static void __exception_irq_entry rda_handle_irq(struct pt_regs *regs)
+{
+	u32 stat = readl(base + RDA_INTC_FINALSTATUS);
+	u32 hwirq;
+
+	while (stat) {
+		hwirq = __fls(stat);
+		handle_domain_irq(rda_irq_domain, hwirq, regs);
+		stat &= ~(1 << hwirq);
+	}
+}
+
+static struct irq_chip rda_irq_chip = {
+	.name		= "rda-intc",
+	.irq_ack	= rda_intc_mask_irq,

You're joking, right? What does it mean to implement both ack as mask
when you already have mask?

Right, but I just followed what other drivers were doing (irq-sa11x0). Will
remove it.

quoted

+	.irq_mask	= rda_intc_mask_irq,
+	.irq_unmask	= rda_intc_unmask_irq,
+	.irq_set_type	= rda_intc_set_type,
+	.irq_disable	= rda_intc_mask_irq,

What is this disable for? Implementing enable/disable only makes sense
if their different implementation differs from mask/unmask (and that
they add some real value, such as allocating resource).

Okay. Will remove this callback also.

quoted

+};
+
+static int rda_irq_map(struct irq_domain *d,
+		       unsigned int virq, irq_hw_number_t hw)
+{
+	irq_set_status_flags(virq, IRQ_LEVEL);
+	irq_set_chip_and_handler(virq, &rda_irq_chip, handle_level_irq);

The set_type callback is specially puzzling when you set everything to
be level...

As said above, set_type callback will be removed since the hardware
can't handle any other interrupt types.

quoted

+	irq_set_chip_data(virq, d->host_data);
+	irq_set_probe(virq);
+
+	return 0;
+}
+
+static const struct irq_domain_ops rda_irq_domain_ops = {
+	.map = rda_irq_map,
+	.xlate = irq_domain_xlate_onecell,

... and don't have any way to express an edge interrupt in DT.

Above comment applies here.

quoted

+};
+
+static int __init rda8810_intc_init(struct device_node *node,
+				    struct device_node *parent)
+{
+	base = of_io_request_and_map(node, 0, "rda-intc");
+	if (!base)
+		return -ENXIO;
+	/*
+	 * Mask, and invalid all interrupt sources
+	 */
+	writel(RDA_IRQ_MASK_ALL, base + RDA_INTC_MASK_CLR);
+
+	rda_irq_domain = irq_domain_create_linear(&node->fwnode, RDA_NR_IRQS,
+						  &rda_irq_domain_ops, base);
+	WARN_ON(!rda_irq_domain);

Just WARN_ON(), and carry on? Please implement some error handling.

Sure. Which one would you recommend? Panic or returning -ENXIO?

Thanks,
Mani

quoted

+
+	set_handle_irq(rda_handle_irq);
+
+	return 0;
+}
+
+IRQCHIP_DECLARE(rda_intc, "rda,8810pl-intc", rda8810_intc_init);

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...