Re: [PATCH 2/6] irqchip: Supply new driver for STi based devices

[Jason Cooper]

On Tue, Jul 29, 2014 at 03:05:40PM +0100, Lee Jones wrote:
> This driver is used to enable System Configuration Register controlled
> External, CTI (Core Sight), PMU (Performance Management), and PL310 L2
> Cache IRQs prior to use.
> 
> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
>  drivers/irqchip/Kconfig  |   7 ++
>  drivers/irqchip/Makefile |   1 +
>  drivers/irqchip/irq-st.c | 206 +++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 214 insertions(+)
>  create mode 100644 drivers/irqchip/irq-st.c
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index bbb746e..7252de9 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -91,3 +91,10 @@ config IRQ_CROSSBAR
>  	  The primary irqchip invokes the crossbar's callback which inturn allocates
>  	  a free irq and configures the IP. Thus the peripheral interrupts are
>  	  routed to one of the free irqchip interrupt lines.
> +
> +config ST_IRQCHIP
> +	bool
> +	select REGMAP
> +	select MFD_SYSCON
> +	help
> +	  Enables SysCfg Controlled IRQs on STi based platforms.

Now that I have my head above water (a bit) wrt irqchip, I really don't
like the hot mess that this file has become...

> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 62a13e5..f859c14 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -30,3 +30,4 @@ obj-$(CONFIG_XTENSA)			+= irq-xtensa-pic.o
>  obj-$(CONFIG_XTENSA_MX)			+= irq-xtensa-mx.o
>  obj-$(CONFIG_IRQ_CROSSBAR)		+= irq-crossbar.o
>  obj-$(CONFIG_BRCMSTB_L2_IRQ)		+= irq-brcmstb-l2.o
> +obj-$(CONFIG_ST_IRQCHIP)		+= irq-st.o
> diff --git a/drivers/irqchip/irq-st.c b/drivers/irqchip/irq-st.c
> new file mode 100644
> index 0000000..f31126f
> --- /dev/null
> +++ b/drivers/irqchip/irq-st.c
> @@ -0,0 +1,206 @@
> +/*
> + *  drivers/irqchip/irq-st.c
> + *
> + *  Copyright (C) 2014 STMicroelectronics â All Rights Reserved
> + *
> + *  Author: Lee Jones <lee.jones@xxxxxxxxxx>
> + *
> + *  This is a re-write of Christophe Kerello's PMU driver.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <dt-bindings/interrupt-controller/irq-st.h>
> +#include <linux/err.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +#define STIH415_SYSCFG_642		0x0a8
> +#define STIH416_SYSCFG_7543		0x87c
> +#define STIH407_SYSCFG_5102		0x198
> +#define STID127_SYSCFG_734		0x088
> +
> +#define ST_A9_IRQ_MASK			0x001FFFFF
> +#define ST_A9_IRQ_MAX_CHANS		2
> +
> +#define ST_A9_IRQ_EN_CTI_0		BIT(0)
> +#define ST_A9_IRQ_EN_CTI_1		BIT(1)
> +#define ST_A9_IRQ_EN_PMU_0		BIT(2)
> +#define ST_A9_IRQ_EN_PMU_1		BIT(3)
> +#define ST_A9_IRQ_EN_pl310_L2		BIT(4)

PL310

> +#define ST_A9_IRQ_EN_EXT_0		BIT(5)
> +#define ST_A9_IRQ_EN_EXT_1		BIT(6)
> +#define ST_A9_IRQ_EN_EXT_2		BIT(7)
> +
> +#define ST_A9_FIQ_N_SEL(dev, chan)	(dev << (8  + (chan * 3)))
> +#define ST_A9_IRQ_N_SEL(dev, chan)	(dev << (14 + (chan * 3)))
> +#define ST_A9_EXTIRQ_INV_SEL(dev)	(dev << 20)
> +
> +struct st_irq_syscfg {
> +	struct regmap *regmap;
> +	unsigned int syscfg;
> +	unsigned int result;

result seems odd here.  It sounds like you're storing a return value,
when in fact, it looks like you are using it to determine whether or not
to invert...  Perhaps a different variable name here?

> +	bool ext_inverted;
> +};
> +
> +static const struct of_device_id st_irq_syscfg_match[] = {
> +	{
> +		.compatible = "st,stih415-irq-syscfg",
> +		.data = (void *)STIH415_SYSCFG_642,
> +	},
> +	{
> +		.compatible = "st,stih416-irq-syscfg",
> +		.data = (void *)STIH416_SYSCFG_7543,
> +	},
> +	{
> +		.compatible = "st,stih407-irq-syscfg",
> +		.data = (void *)STIH407_SYSCFG_5102,
> +	},
> +	{
> +		.compatible = "st,stid127-irq-syscfg",
> +		.data = (void *)STID127_SYSCFG_734,
> +	},
> +	{}
> +};
> +
> +static int st_irq_xlate(struct platform_device *pdev,
> +			int device, int channel, bool irq)
> +{
> +	struct st_irq_syscfg *ddata = dev_get_drvdata(&pdev->dev);
> +
> +	/* Set the device enable bit. */
> +	switch (device) {
> +	case ST_IRQ_SYSCFG_EXT_0 :
> +		ddata->result |= ST_A9_IRQ_EN_EXT_0;
> +		break;
> +	case ST_IRQ_SYSCFG_EXT_1 :
> +		ddata->result |= ST_A9_IRQ_EN_EXT_1;
> +		break;
> +	case ST_IRQ_SYSCFG_EXT_2 :
> +		ddata->result |= ST_A9_IRQ_EN_EXT_2;
> +		break;
> +	case ST_IRQ_SYSCFG_CTI_0 :
> +		ddata->result |= ST_A9_IRQ_EN_CTI_0;
> +		break;
> +	case ST_IRQ_SYSCFG_CTI_1 :
> +		ddata->result |= ST_A9_IRQ_EN_CTI_1;
> +		break;
> +	case ST_IRQ_SYSCFG_PMU_0 :
> +		ddata->result |= ST_A9_IRQ_EN_PMU_0;
> +		break;
> +	case ST_IRQ_SYSCFG_PMU_1 :
> +		ddata->result |= ST_A9_IRQ_EN_PMU_1;
> +		break;
> +	case ST_IRQ_SYSCFG_pl310_L2 :
> +		ddata->result |= ST_A9_IRQ_EN_pl310_L2;
> +		break;
> +	case ST_IRQ_SYSCFG_DISABLED :
> +		return 0;
> +	default :
> +		dev_err(&pdev->dev, "Unrecognised device %d\n", device);

dev_dbg

> +		return -EINVAL;
> +	}
> +
> +	/* Select IRQ/FIQ channel for device. */
> +	ddata->result |= irq ?
> +		ST_A9_IRQ_N_SEL(device, channel) :
> +		ST_A9_FIQ_N_SEL(device, channel);
> +
> +	return 0;
> +}
> +
> +static int st_irq_syscfg_enable(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct st_irq_syscfg *ddata = dev_get_drvdata(&pdev->dev);
> +	int channels, ret, i;
> +	u32 device, invert;
> +


> +	channels = of_property_count_u32_elems(np, "st,irq-device");
> +	if (channels != ST_A9_IRQ_MAX_CHANS) {
> +		dev_err(&pdev->dev, "st,enable-irq-device must have 2 elems\n");
> +		return -EINVAL;
> +	}
> +
> +	channels = of_property_count_u32_elems(np, "st,fiq-device");
> +	if (channels != ST_A9_IRQ_MAX_CHANS) {
> +		dev_err(&pdev->dev, "st,enable-fiq-device must have 2 elems\n");
> +		return -EINVAL;
> +	}

I would drop these two blocks,

> +
> +	for (i = 0; i < channels; i++) {

then use ST_A9_IRQ_MAX_CHANS here

> +		of_property_read_u32_index(np,"st,irq-device", i, &device);

and dev_dbg() if of_property_read_u32_index() returns an error

> +
> +		ret = st_irq_xlate(pdev, device, i, true);
> +		if (ret)
> +			return ret;
> +
> +		of_property_read_u32_index(np,"st,fiq-device", i, &device);

for both of these.

> +
> +		ret = st_irq_xlate(pdev, device, i, false);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	/* External IRQs may be inverted. */
> +	of_property_read_u32(np, "st,invert-ext", &invert);
> +	ddata->result |= ST_A9_EXTIRQ_INV_SEL(invert);
> +
> +	return regmap_update_bits(ddata->regmap, ddata->syscfg,
> +				  ST_A9_IRQ_MASK, ddata->result);
> +}
> +
> +int st_irq_syscfg_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	const struct of_device_id *match;
> +	struct st_irq_syscfg *ddata;
> +
> +	match = of_match_device(st_irq_syscfg_match, &pdev->dev);
> +	if (!np)

if (!match) ?

> +		return -ENODEV;
> +
> +	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
> +	if (!ddata)
> +		return -ENOMEM;
> +
> +	ddata->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
> +	if (IS_ERR(ddata->regmap)) {
> +		dev_err(&pdev->dev, "syscfg phandle missing\n");

dev_dbg

> +		return PTR_ERR(ddata->regmap);
> +	}
> +
> +	dev_set_drvdata(&pdev->dev, ddata);
> +
> +	return st_irq_syscfg_enable(pdev);
> +}
> +
> +static int st_irq_syscfg_resume(struct device *dev)
> +{
> +	struct st_irq_syscfg *ddata = dev_get_drvdata(dev);
> +
> +	return regmap_update_bits(ddata->regmap, ddata->syscfg,
> +				  ST_A9_IRQ_MASK, ddata->result);
> +}
> +
> +static SIMPLE_DEV_PM_OPS(st_irq_syscfg_pm_ops, NULL, st_irq_syscfg_resume);
> +
> +static struct platform_driver st_irq_syscfg_driver = {
> +	.driver = {
> +		.name = "st_irq_syscfg",
> +		.pm = &st_irq_syscfg_pm_ops,
> +		.of_match_table = st_irq_syscfg_match,
> +	},
> +	.probe = st_irq_syscfg_probe,
> +};
> +
> +static int __init st_irq_syscfg_init(void)
> +{
> +	return platform_driver_register(&st_irq_syscfg_driver);
> +}
> +core_initcall(st_irq_syscfg_init);

thx,

Jason.
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