Re: [PATCH 06/18] irqchip: add sl28cpld interrupt controller support

[Guenter Roeck <linux@roeck-us.net>]

On 3/17/20 1:50 PM, Michael Walle wrote:
> This patch adds support for the interrupt controller inside the sl28
> CPLD management controller.
> 
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
>  drivers/irqchip/Kconfig        |  3 ++
>  drivers/irqchip/Makefile       |  1 +
>  drivers/irqchip/irq-sl28cpld.c | 92 ++++++++++++++++++++++++++++++++++
>  drivers/mfd/Kconfig            |  4 +-
>  4 files changed, 98 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/irqchip/irq-sl28cpld.c
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 24fe08702ef7..3fd7415c8b55 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -246,6 +246,9 @@ config RENESAS_RZA1_IRQC
>  	  Enable support for the Renesas RZ/A1 Interrupt Controller, to use up
>  	  to 8 external interrupts with configurable sense select.
>  
> +config SL28CPLD_INTC
> +	bool
> +
>  config ST_IRQCHIP
>  	bool
>  	select REGMAP
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index eae0d78cbf22..0f4a37782609 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -105,3 +105,4 @@ obj-$(CONFIG_MADERA_IRQ)		+= irq-madera.o
>  obj-$(CONFIG_LS1X_IRQ)			+= irq-ls1x.o
>  obj-$(CONFIG_TI_SCI_INTR_IRQCHIP)	+= irq-ti-sci-intr.o
>  obj-$(CONFIG_TI_SCI_INTA_IRQCHIP)	+= irq-ti-sci-inta.o
> +obj-$(CONFIG_SL28CPLD_INTC)		+= irq-sl28cpld.o
> diff --git a/drivers/irqchip/irq-sl28cpld.c b/drivers/irqchip/irq-sl28cpld.c
> new file mode 100644
> index 000000000000..fa52ed79137b
> --- /dev/null
> +++ b/drivers/irqchip/irq-sl28cpld.c
> @@ -0,0 +1,92 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * SMARC-sAL28 Interrupt core driver.
> + *
> + * Copyright 2019 Kontron Europe GmbH
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_platform.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/interrupt.h>
> +#include <linux/mfd/core.h>
> +
> +#define INTC_IE 0
> +#define INTC_IP 1
> +
> +static const struct regmap_irq sl28cpld_irqs[] = {
> +	REGMAP_IRQ_REG_LINE(0, 8),
> +	REGMAP_IRQ_REG_LINE(1, 8),
> +	REGMAP_IRQ_REG_LINE(2, 8),
> +	REGMAP_IRQ_REG_LINE(3, 8),
> +	REGMAP_IRQ_REG_LINE(4, 8),
> +	REGMAP_IRQ_REG_LINE(5, 8),
> +	REGMAP_IRQ_REG_LINE(6, 8),
> +	REGMAP_IRQ_REG_LINE(7, 8),
> +};
> +
> +struct sl28cpld_intc {
> +	struct regmap *regmap;
> +	struct regmap_irq_chip chip;
> +	struct regmap_irq_chip_data *irq_data;
> +};
> +
> +static int sl28cpld_intc_probe(struct platform_device *pdev)
> +{
> +	struct sl28cpld_intc *irqchip;
> +	struct resource *res;
> +	unsigned int irq;
> +	int ret;
> +
> +	irqchip = devm_kzalloc(&pdev->dev, sizeof(*irqchip), GFP_KERNEL);
> +	if (!irqchip)
> +		return -ENOMEM;
> +
> +	if (!pdev->dev.parent)
> +		return -ENODEV;
> +
> +	irqchip->regmap = dev_get_regmap(pdev->dev.parent, NULL);
> +	if (!irqchip->regmap)
> +		return -ENODEV;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
> +	if (!res)
> +		return -EINVAL;
> +
> +	irqchip->chip.name = "sl28cpld-intc";
> +	irqchip->chip.irqs = sl28cpld_irqs;
> +	irqchip->chip.num_irqs = ARRAY_SIZE(sl28cpld_irqs);
> +	irqchip->chip.num_regs = 1;
> +	irqchip->chip.status_base = res->start + INTC_IP;
> +	irqchip->chip.mask_base = res->start + INTC_IE;
> +	irqchip->chip.mask_invert = true,
> +	irqchip->chip.ack_base = res->start + INTC_IP;
> +
> +	ret = devm_regmap_add_irq_chip(&pdev->dev, irqchip->regmap, irq,
> +				       IRQF_SHARED | IRQF_ONESHOT, 0,
> +				       &irqchip->chip, &irqchip->irq_data);
> +	if (ret)
> +		return ret;
> +	dev_info(&pdev->dev, "registered IRQ %d\n", irq);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver sl28cpld_intc_driver = {
> +	.probe	= sl28cpld_intc_probe,
> +	.driver = {
> +		.name = "sl28cpld-intc",
> +	}
> +};
> +module_platform_driver(sl28cpld_intc_driver);
> +
> +MODULE_DESCRIPTION("sl28cpld Interrupt Controller Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 01588c366476..4f741d640705 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -2060,12 +2060,12 @@ config SGI_MFD_IOC3
>  	  then say Y. Otherwise say N.
>  
>  config MFD_SL28CPLD
> -	tristate "Kontron sl28 core driver"
> +	bool "Kontron sl28 core driver"

This is .... unusual. Why declare it tristate only to re-declare it bool in the next patch ?
It does explain the I2C=y, but I really think it should be bool from the start if it ends up
there.

>  	depends on I2C=y
>  	depends on OF
>  	select REGMAP_I2C
>  	select REGMAP_IRQ
> -	select SL28CPLD_IRQ
> +	select SL28CPLD_INTC

What is the point of introducing SL28CPLD_IRQ in the first place ?

>  	select MFD_CORE
>  	help
>  	  This option enables support for the board management controller
>