RE: [PATCH v3 2/2] irqchip: Add support for Renesas RZ/N1 GPIO interrupt multiplexer

[Phil Edworthy]

Hi Marc,

> On Tue, 19 Feb 2019 15:27:25 +0000
> Phil Edworthy <phil.edworthy@xxxxxxxxxxx> wrote:
> 
> > Hello,
> >
> > Any comments on this patch?
> 
> Err... I'm afraid it fell through the cracks. It's been three months, and I've
> paged out most of last year.
> 
> Can you please resend it on top of a recent -rc, and I'll try to have a look. No
> promise though.

Thanks, appreciate it you can!
Phil

> 
> Thanks,
> 
> 	M.
> 
> >
> > Thanks
> > Phil
> >
> > > -----Original Message-----
> > > From: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
> > > Sent: 13 November 2018 13:09
> > > To: Marc Zyngier <marc.zyngier@xxxxxxx>; Thomas Gleixner
> > > <tglx@xxxxxxxxxxxxx>; Jason Cooper <jason@xxxxxxxxxxxxxx>
> > > Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>; linux-renesas-
> > > soc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Phil Edworthy
> > > <phil.edworthy@xxxxxxxxxxx>
> > > Subject: [PATCH v3 2/2] irqchip: Add support for Renesas RZ/N1 GPIO
> > > interrupt multiplexer
> > >
> > > On RZ/N1 devices, there are 3 Synopsys DesignWare GPIO blocks each
> > > configured to have 32 interrupt outputs, so we have a total of 96
> > > GPIO interrupts. All of these are passed to the GPIO IRQ Muxer,
> > > which selects
> > > 8 of the GPIO interrupts to pass onto the GIC. The interrupt signals
> > > aren't latched, so there is nothing to do in this driver when an
> > > interrupt is received, other than tell the corresponding GPIO block.
> > >
> > > Signed-off-by: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
> > > ---
> > > v3:
> > >  - Use 'interrupt-map' DT property to map the interrupts, this is very
> similar
> > >    to PCIe MSI. The only difference is that we need to get hold of the
> interrupt
> > >    specifier for the interupts coming into the irqmux.
> > >  - Do not use a chained interrupt controller.
> > > v2:
> > >  - Use interrupt-map to allow the GPIO controller info to be specified
> > >    as part of the irq.
> > >  - Renamed struct and funcs from 'girq' to a more comprehenisble
> 'irqmux'.
> > > ---
> > >  drivers/irqchip/Kconfig        |   9 ++
> > >  drivers/irqchip/Makefile       |   1 +
> > >  drivers/irqchip/rzn1-irq-mux.c | 205
> > > +++++++++++++++++++++++++++++++++
> > >  3 files changed, 215 insertions(+)
> > >  create mode 100644 drivers/irqchip/rzn1-irq-mux.c
> > >
> > > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index
> > > 96451b581452..53c54bba1dd8 100644
> > > --- a/drivers/irqchip/Kconfig
> > > +++ b/drivers/irqchip/Kconfig
> > > @@ -204,6 +204,15 @@ config RENESAS_IRQC
> > >  	select GENERIC_IRQ_CHIP
> > >  	select IRQ_DOMAIN
> > >
> > > +config RENESAS_RZN1_IRQ_MUX
> > > +	bool "Renesas RZ/N1 GPIO IRQ multiplexer support"
> > > +	depends on ARCH_RZN1
> > > +	select IRQ_DOMAIN
> > > +	help
> > > +	  Say yes here to add support for the GPIO IRQ multiplexer
> > > embedded
> > > +	  in Renesas RZ/N1 SoC devices. The GPIO IRQ Muxer selects which of
> > > +	  the interrupts coming from the GPIO controllers are used.
> > > +
> > >  config ST_IRQCHIP
> > >  	bool
> > >  	select REGMAP
> > > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > > index b822199445ff..b090f84dd42e 100644
> > > --- a/drivers/irqchip/Makefile
> > > +++ b/drivers/irqchip/Makefile
> > > @@ -45,6 +45,7 @@ obj-$(CONFIG_SIRF_IRQ)			+=
> irq-
> > > sirfsoc.o
> > >  obj-$(CONFIG_JCORE_AIC)			+= irq-jcore-aic.o
> > >  obj-$(CONFIG_RENESAS_INTC_IRQPIN)	+= irq-renesas-intc-irqpin.o
> > >  obj-$(CONFIG_RENESAS_IRQC)		+= irq-renesas-irqc.o
> > > +obj-$(CONFIG_RENESAS_RZN1_IRQ_MUX)	+= rzn1-irq-mux.o
> > >  obj-$(CONFIG_VERSATILE_FPGA_IRQ)	+= irq-versatile-fpga.o
> > >  obj-$(CONFIG_ARCH_NSPIRE)		+= irq-zevio.o
> > >  obj-$(CONFIG_ARCH_VT8500)		+= irq-vt8500.o
> > > diff --git a/drivers/irqchip/rzn1-irq-mux.c
> > > b/drivers/irqchip/rzn1-irq-mux.c new file mode 100644 index
> > > 000000000000..ee7810b9b3f3
> > > --- /dev/null
> > > +++ b/drivers/irqchip/rzn1-irq-mux.c
> > > @@ -0,0 +1,205 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * RZ/N1 GPIO Interrupt Multiplexer
> > > + *
> > > + * Copyright (C) 2018 Renesas Electronics Europe Limited
> > > + *
> > > + * On RZ/N1 devices, there are 3 Synopsys DesignWare GPIO blocks
> > > +each configured
> > > + * to have 32 interrupt outputs, so we have a total of 96 GPIO interrupts.
> > > + * All of these are passed to the GPIO IRQ Muxer, which selects 8
> > > +of the GPIO
> > > + * interrupts to pass onto the GIC.
> > > + */
> > > +
> > > +#include <linux/interrupt.h>
> > > +#include <linux/irq.h>
> > > +#include <linux/irqdomain.h>
> > > +#include <linux/kernel.h>
> > > +#include <linux/module.h>
> > > +#include <linux/of_irq.h>
> > > +#include <linux/of_platform.h>
> > > +
> > > +#define MAX_NR_INPUT_IRQS	96
> > > +#define MAX_NR_OUTPUT_IRQS	8
> > > +
> > > +/*
> > > + * "interrupt-map" consists of 1 interrupt cell, 0 address cells,
> > > +phandle to
> > > + * interrupt parent, and parent interrupt specifier (3 cells for
> > > +GIC), giving
> > > + * a total of 5 cells.
> > > + */
> > > +#define IMAP_LENGTH		5
> > > +
> > > +struct irqmux_priv;
> > > +struct irqmux_one {
> > > +	unsigned int irq;
> > > +	unsigned int src_hwirq;
> > > +	struct irqmux_priv *priv;
> > > +};
> > > +
> > > +struct irqmux_priv {
> > > +	struct device *dev;
> > > +	struct irq_domain *irq_domain;
> > > +	unsigned int nr_irqs;
> > > +	struct irqmux_one mux[MAX_NR_OUTPUT_IRQS]; };
> > > +
> > > +static irqreturn_t irqmux_handler(int irq, void *data) {
> > > +	struct irqmux_one *mux = data;
> > > +	struct irqmux_priv *priv = mux->priv;
> > > +	unsigned int virq;
> > > +
> > > +	virq = irq_find_mapping(priv->irq_domain, mux->src_hwirq);
> > > +
> > > +	generic_handle_irq(virq);
> > > +
> > > +	return IRQ_HANDLED;
> > > +}
> > > +
> > > +static int irqmux_domain_map(struct irq_domain *h, unsigned int irq,
> > > +			     irq_hw_number_t hwirq)
> > > +{
> > > +	irq_set_chip_data(irq, h->host_data);
> > > +	irq_set_chip_and_handler(irq, &dummy_irq_chip,
> > > handle_simple_irq);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static const struct irq_domain_ops irqmux_domain_ops = {
> > > +	.map = irqmux_domain_map,
> > > +};
> > > +
> > > +static int irqmux_probe(struct platform_device *pdev) {
> > > +	struct device *dev = &pdev->dev;
> > > +	struct device_node *np = dev->of_node;
> > > +	struct resource *res;
> > > +	u32 __iomem *regs;
> > > +	struct irqmux_priv *priv;
> > > +	unsigned int i;
> > > +	int nr_irqs;
> > > +	int ret;
> > > +	const __be32 *imap;
> > > +	int imaplen;
> > > +
> > > +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > > +	if (!priv)
> > > +		return -ENOMEM;
> > > +
> > > +	priv->dev = dev;
> > > +	platform_set_drvdata(pdev, priv);
> > > +
> > > +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > > +	regs = devm_ioremap_resource(dev, res);
> > > +	if (IS_ERR(regs))
> > > +		return PTR_ERR(regs);
> > > +
> > > +	nr_irqs = of_irq_count(np);
> > > +	if (nr_irqs < 0)
> > > +		return nr_irqs;
> > > +
> > > +	if (nr_irqs > MAX_NR_OUTPUT_IRQS) {
> > > +		dev_err(dev, "too many output interrupts\n");
> > > +		return -ENOENT;
> > > +	}
> > > +
> > > +	priv->nr_irqs = nr_irqs;
> > > +
> > > +	/* Look for the interrupt-map */
> > > +	imap = of_get_property(np, "interrupt-map", &imaplen);
> > > +	if (!imap)
> > > +		return -ENOENT;
> > > +	imaplen /= IMAP_LENGTH * sizeof(__be32);
> > > +
> > > +	/* Sometimes not all muxs are used */
> > > +	if (imaplen < priv->nr_irqs)
> > > +		priv->nr_irqs = imaplen;
> > > +
> > > +	/* Create IRQ domain for the interrupts coming from the GPIO
> > > +blocks
> > > */
> > > +	priv->irq_domain = irq_domain_add_linear(np,
> > > MAX_NR_INPUT_IRQS,
> > > +						 &irqmux_domain_ops, priv);
> > > +	if (!priv->irq_domain)
> > > +		return -ENOMEM;
> > > +
> > > +	for (i = 0; i < MAX_NR_INPUT_IRQS; i++)
> > > +		irq_create_mapping(priv->irq_domain, i);
> > > +
> > > +	for (i = 0; i < priv->nr_irqs; i++) {
> > > +		struct irqmux_one *mux = &priv->mux[i];
> > > +
> > > +		ret = irq_of_parse_and_map(np, i);
> > > +		if (ret < 0) {
> > > +			ret = -ENOENT;
> > > +			goto err;
> > > +		}
> > > +
> > > +		mux->irq = ret;
> > > +		mux->priv = priv;
> > > +
> > > +		/*
> > > +		 * We need the first cell of the interrupt-map to configure
> > > +		 * the hardware.
> > > +		 */
> > > +		mux->src_hwirq = be32_to_cpu(*imap);
> > > +		imap += IMAP_LENGTH;
> > > +
> > > +		dev_info(dev, "%u: %u mapped irq %u\n", i,  mux-
> > > >src_hwirq,
> > > +			 mux->irq);
> > > +
> > > +		ret = devm_request_irq(dev, mux->irq, irqmux_handler,
> > > +				       IRQF_SHARED | IRQF_NO_THREAD,
> > > +				       "irqmux", mux);
> > > +		if (ret < 0) {
> > > +			dev_err(dev, "failed to request IRQ: %d\n", ret);
> > > +			goto err;
> > > +		}
> > > +
> > > +		/* Set up the hardware to pass the interrupt through */
> > > +		writel(mux->src_hwirq, &regs[i]);
> > > +	}
> > > +
> > > +	dev_info(dev, "probed, %d gpio interrupts\n", priv->nr_irqs);
> > > +
> > > +	return 0;
> > > +
> > > +err:
> > > +	while (i--)
> > > +		irq_dispose_mapping(priv->mux[i].irq);
> > > +	irq_domain_remove(priv->irq_domain);
> > > +
> > > +	return ret;
> > > +}
> > > +
> > > +static int irqmux_remove(struct platform_device *pdev) {
> > > +	struct irqmux_priv *priv = platform_get_drvdata(pdev);
> > > +	unsigned int i;
> > > +
> > > +	for (i = 0; i < priv->nr_irqs; i++)
> > > +		irq_dispose_mapping(priv->mux[i].irq);
> > > +	irq_domain_remove(priv->irq_domain);
> > > +
> > > +	return 0;
> > > +}
> > > +
> > > +static const struct of_device_id irqmux_match[] = {
> > > +	{ .compatible = "renesas,rzn1-gpioirqmux", },
> > > +	{ /* sentinel */ },
> > > +};
> > > +
> > > +MODULE_DEVICE_TABLE(of, irqmux_match);
> > > +
> > > +static struct platform_driver irqmux_driver = {
> > > +	.driver = {
> > > +		.name = "gpio_irq_mux",
> > > +		.owner = THIS_MODULE,
> > > +		.of_match_table = irqmux_match,
> > > +	},
> > > +	.probe = irqmux_probe,
> > > +	.remove = irqmux_remove,
> > > +};
> > > +
> > > +module_platform_driver(irqmux_driver);
> > > +
> > > +MODULE_DESCRIPTION("Renesas RZ/N1 GPIO IRQ Multiplexer Driver");
> > > +MODULE_AUTHOR("Phil Edworthy <phil.edworthy@xxxxxxxxxxx>");
> > > +MODULE_LICENSE("GPL v2");
> > > --
> > > 2.17.1
> >
> 
> 
> 
> --
> Without deviation from the norm, progress is not possible.