[PATCH v2 0/8] irqchip: New driver for ST's SysCfg controlled IRQs

[PATCH v2 0/8] irqchip: New driver for ST's SysCfg controlled IRQs

[Lee Jones]

This driver enables IRQs which are controlled using System Configuration
registers.  Without it Performance Monitoring, Core Sight Tracing and some
L2 Caches will fail to function.

v1 => v2:
 - Fixed up Jason's review comments

Lee Jones (8):
  dt: bindings: Supply shared ST IRQ defines
  irqchip: Supply new driver for STi based devices
  irqchip: irq-st: Add documentation for STi based syscfg IRQs
  ARM: STi: STiH416: Enable Cortex-A9 PMU support
  ARM: STi: STiH416: Enable PMU IRQs
  ARM: STi: STiH407: Enable Cortex-A9 PMU support
  ARM: STi: STiH407: Enable PMU IRQs
  ARM: STI: Ensure requested STi's SysCfg Controlled IRQs are enabled at
    boot

 .../interrupt-controller/st,sti-irq-syscfg.txt     |  35 ++++
 arch/arm/boot/dts/stih407.dtsi                     |  16 ++
 arch/arm/boot/dts/stih416.dtsi                     |  16 ++
 arch/arm/mach-sti/Kconfig                          |   1 +
 drivers/irqchip/Kconfig                            |   7 +
 drivers/irqchip/Makefile                           |   1 +
 drivers/irqchip/irq-st.c                           | 208 +++++++++++++++++++++
 include/dt-bindings/interrupt-controller/irq-st.h  |  30 +++
 8 files changed, 314 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt
 create mode 100644 drivers/irqchip/irq-st.c
 create mode 100644 include/dt-bindings/interrupt-controller/irq-st.h

-- 
1.9.1

[PATCH v2 1/8] dt: bindings: Supply shared ST IRQ defines

[Lee Jones]

These defines are used to allow values used for configuration to be
easily human readable and will lessen the chance of logical mistakes.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 include/dt-bindings/interrupt-controller/irq-st.h | 30 +++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 include/dt-bindings/interrupt-controller/irq-st.h

diff --git a/include/dt-bindings/interrupt-controller/irq-st.h b/include/dt-bindings/interrupt-controller/irq-st.h
new file mode 100644
index 0000000..4c59ace
--- /dev/null
+++ b/include/dt-bindings/interrupt-controller/irq-st.h
@@ -0,0 +1,30 @@
+/*
+ *  include/linux/irqchip/irq-st.h
+ *
+ *  Copyright (C) 2014 STMicroelectronics ? All Rights Reserved
+ *
+ *  Author: Lee Jones <lee.jones@linaro.org>
+ *
+ * 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.
+ */
+
+#ifndef _DT_BINDINGS_INTERRUPT_CONTROLLER_ST_H
+#define _DT_BINDINGS_INTERRUPT_CONTROLLER_ST_H
+
+#define ST_IRQ_SYSCFG_EXT_0		0
+#define ST_IRQ_SYSCFG_EXT_1		1
+#define ST_IRQ_SYSCFG_EXT_2		2
+#define ST_IRQ_SYSCFG_CTI_0		3
+#define ST_IRQ_SYSCFG_CTI_1		4
+#define ST_IRQ_SYSCFG_PMU_0		5
+#define ST_IRQ_SYSCFG_PMU_1		6
+#define ST_IRQ_SYSCFG_pl310_L2		7
+#define ST_IRQ_SYSCFG_DISABLED		0xFFFFFFFF
+
+#define ST_IRQ_SYSCFG_EXT_1_INV		0x1
+#define ST_IRQ_SYSCFG_EXT_2_INV		0x2
+#define ST_IRQ_SYSCFG_EXT_3_INV		0x4
+
+#endif
-- 
1.9.1

[PATCH v2 2/8] irqchip: Supply new driver for STi based devices

[Lee Jones]

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@linaro.org>
---
 drivers/irqchip/Kconfig  |   7 ++
 drivers/irqchip/Makefile |   1 +
 drivers/irqchip/irq-st.c | 208 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 216 insertions(+)
 create mode 100644 drivers/irqchip/irq-st.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index b21f12f..e502f15 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -93,6 +93,13 @@ config RENESAS_IRQC
 	bool
 	select IRQ_DOMAIN
 
+config ST_IRQCHIP
+	bool
+	select REGMAP
+	select MFD_SYSCON
+	help
+	  Enables SysCfg Controlled IRQs on STi based platforms.
+
 config TB10X_IRQC
 	bool
 	select IRQ_DOMAIN
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 173bb5f..293b68d 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_RENESAS_IRQC)		+= irq-renesas-irqc.o
 obj-$(CONFIG_VERSATILE_FPGA_IRQ)	+= irq-versatile-fpga.o
 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-$(CONFIG_XTENSA)			+= irq-xtensa-pic.o
 obj-$(CONFIG_XTENSA_MX)			+= irq-xtensa-mx.o
diff --git a/drivers/irqchip/irq-st.c b/drivers/irqchip/irq-st.c
new file mode 100644
index 0000000..181dad1
--- /dev/null
+++ b/drivers/irqchip/irq-st.c
@@ -0,0 +1,208 @@
+/*
+ *  drivers/irqchip/irq-st.c
+ *
+ *  Copyright (C) 2014 STMicroelectronics ? All Rights Reserved
+ *
+ *  Author: Lee Jones <lee.jones@linaro.org>
+ *
+ *  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)
+#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 config;
+	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->config |= ST_A9_IRQ_EN_EXT_0;
+		break;
+	case ST_IRQ_SYSCFG_EXT_1 :
+		ddata->config |= ST_A9_IRQ_EN_EXT_1;
+		break;
+	case ST_IRQ_SYSCFG_EXT_2 :
+		ddata->config |= ST_A9_IRQ_EN_EXT_2;
+		break;
+	case ST_IRQ_SYSCFG_CTI_0 :
+		ddata->config |= ST_A9_IRQ_EN_CTI_0;
+		break;
+	case ST_IRQ_SYSCFG_CTI_1 :
+		ddata->config |= ST_A9_IRQ_EN_CTI_1;
+		break;
+	case ST_IRQ_SYSCFG_PMU_0 :
+		ddata->config |= ST_A9_IRQ_EN_PMU_0;
+		break;
+	case ST_IRQ_SYSCFG_PMU_1 :
+		ddata->config |= ST_A9_IRQ_EN_PMU_1;
+		break;
+	case ST_IRQ_SYSCFG_pl310_L2 :
+		ddata->config |= ST_A9_IRQ_EN_PL310_L2;
+		break;
+	case ST_IRQ_SYSCFG_DISABLED :
+		return 0;
+	default :
+		dev_err(&pdev->dev, "Unrecognised device %d\n", device);
+		return -EINVAL;
+	}
+
+	/* Select IRQ/FIQ channel for device. */
+	ddata->config |= 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;
+	}
+
+	for (i = 0; i < ST_A9_IRQ_MAX_CHANS; i++) {
+		of_property_read_u32_index(np, "st,irq-device", i, &device);
+
+		ret = st_irq_xlate(pdev, device, i, true);
+		if (ret)
+			return ret;
+
+		of_property_read_u32_index(np, "st,fiq-device", i, &device);
+
+		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->config |= ST_A9_EXTIRQ_INV_SEL(invert);
+
+	return regmap_update_bits(ddata->regmap, ddata->syscfg,
+				  ST_A9_IRQ_MASK, ddata->config);
+}
+
+static 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;
+
+	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
+	if (!ddata)
+		return -ENOMEM;
+
+	match = of_match_device(st_irq_syscfg_match, &pdev->dev);
+	if (!match)
+		return -ENODEV;
+
+	ddata->syscfg = (unsigned int)match->data;
+
+	ddata->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
+	if (IS_ERR(ddata->regmap)) {
+		dev_err(&pdev->dev, "syscfg phandle missing\n");
+		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->config);
+}
+
+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);
-- 
1.9.1

[PATCH v2 2/8] irqchip: Supply new driver for STi based devices

[Arnd Bergmann]

On Tuesday 25 November 2014 16:24:59 Lee Jones wrote:

> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index b21f12f..e502f15 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -93,6 +93,13 @@ config RENESAS_IRQC
>  	bool
>  	select IRQ_DOMAIN
>  
> +config ST_IRQCHIP
> +	bool
> +	select REGMAP
> +	select MFD_SYSCON
> +	help
> +	  Enables SysCfg Controlled IRQs on STi based platforms.
> +

I'm confused by the purpose of this code. It's apparently a driver
in drivers/irqchip, the Kconfig symbol contains the string IRQCHIP,
yet it doesn't actually register an irq_chip.

Also, the name is a bit too generic, ST has lots of different irqchips,
and this apparently isn't even one of them ;-)

	Arnd

[PATCH v2 2/8] irqchip: Supply new driver for STi based devices

[Lee Jones]

On Tue, 25 Nov 2014, Arnd Bergmann wrote:

> On Tuesday 25 November 2014 16:24:59 Lee Jones wrote:
> 
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index b21f12f..e502f15 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -93,6 +93,13 @@ config RENESAS_IRQC
> >  	bool
> >  	select IRQ_DOMAIN
> >  
> > +config ST_IRQCHIP
> > +	bool
> > +	select REGMAP
> > +	select MFD_SYSCON
> > +	help
> > +	  Enables SysCfg Controlled IRQs on STi based platforms.
> > +
> 
> I'm confused by the purpose of this code. It's apparently a driver
> in drivers/irqchip, the Kconfig symbol contains the string IRQCHIP,
> yet it doesn't actually register an irq_chip.
> 
> Also, the name is a bit too generic, ST has lots of different irqchips,
> and this apparently isn't even one of them ;-)

Hmm... now you're going to ask me to remember who I had the
conversation with that alluded to this as the best location for this
driver.  Unfortunately, I cannot.  Can you think of a better place to
put it then?

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

[PATCH v2 2/8] irqchip: Supply new driver for STi based devices

[Arnd Bergmann]

On Thursday 27 November 2014 09:02:55 Lee Jones wrote:
> On Tue, 25 Nov 2014, Arnd Bergmann wrote:
> 
> > On Tuesday 25 November 2014 16:24:59 Lee Jones wrote:
> > 
> > > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > > index b21f12f..e502f15 100644
> > > --- a/drivers/irqchip/Kconfig
> > > +++ b/drivers/irqchip/Kconfig
> > > @@ -93,6 +93,13 @@ config RENESAS_IRQC
> > >     bool
> > >     select IRQ_DOMAIN
> > >  
> > > +config ST_IRQCHIP
> > > +   bool
> > > +   select REGMAP
> > > +   select MFD_SYSCON
> > > +   help
> > > +     Enables SysCfg Controlled IRQs on STi based platforms.
> > > +
> > 
> > I'm confused by the purpose of this code. It's apparently a driver
> > in drivers/irqchip, the Kconfig symbol contains the string IRQCHIP,
> > yet it doesn't actually register an irq_chip.
> > 
> > Also, the name is a bit too generic, ST has lots of different irqchips,
> > and this apparently isn't even one of them 
> 
> Hmm... now you're going to ask me to remember who I had the
> conversation with that alluded to this as the best location for this
> driver.  Unfortunately, I cannot.  Can you think of a better place to
> put it then?

I suspect it's in the right place but should actually be an irqchip
driver. I'm having trouble understanding what this code actually does,
can you you explain the functionality in more detail so we can figure
out what to do with it?

	Arnd

[PATCH v2 2/8] irqchip: Supply new driver for STi based devices

[Lee Jones]

On Thu, 27 Nov 2014, Arnd Bergmann wrote:

> On Thursday 27 November 2014 09:02:55 Lee Jones wrote:
> > On Tue, 25 Nov 2014, Arnd Bergmann wrote:
> > 
> > > On Tuesday 25 November 2014 16:24:59 Lee Jones wrote:
> > > 
> > > > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > > > index b21f12f..e502f15 100644
> > > > --- a/drivers/irqchip/Kconfig
> > > > +++ b/drivers/irqchip/Kconfig
> > > > @@ -93,6 +93,13 @@ config RENESAS_IRQC
> > > >     bool
> > > >     select IRQ_DOMAIN
> > > >  
> > > > +config ST_IRQCHIP
> > > > +   bool
> > > > +   select REGMAP
> > > > +   select MFD_SYSCON
> > > > +   help
> > > > +     Enables SysCfg Controlled IRQs on STi based platforms.
> > > > +
> > > 
> > > I'm confused by the purpose of this code. It's apparently a driver
> > > in drivers/irqchip, the Kconfig symbol contains the string IRQCHIP,
> > > yet it doesn't actually register an irq_chip.
> > > 
> > > Also, the name is a bit too generic, ST has lots of different irqchips,
> > > and this apparently isn't even one of them 
> > 
> > Hmm... now you're going to ask me to remember who I had the
> > conversation with that alluded to this as the best location for this
> > driver.  Unfortunately, I cannot.  Can you think of a better place to
> > put it then?
> 
> I suspect it's in the right place but should actually be an irqchip
> driver. I'm having trouble understanding what this code actually does,
> can you you explain the functionality in more detail so we can figure
> out what to do with it?

In the simplest terms it's an IRQ unmasker.  A9 Core IRQs are disabled
on boot; PMU, CTI (CoreSight), PL310_L2 and EXT.  In order for you to
make use of them they need to be unmasked in SYSCFG.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

[PATCH v2 2/8] irqchip: Supply new driver for STi based devices

[Arnd Bergmann]

On Thursday 27 November 2014 09:29:01 Lee Jones wrote:
> On Thu, 27 Nov 2014, Arnd Bergmann wrote:
> > On Thursday 27 November 2014 09:02:55 Lee Jones wrote:
> > > On Tue, 25 Nov 2014, Arnd Bergmann wrote:
> > > 
> > > > On Tuesday 25 November 2014 16:24:59 Lee Jones wrote:
> > > > 
> > > > > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > > > > index b21f12f..e502f15 100644
> > > > > --- a/drivers/irqchip/Kconfig
> > > > > +++ b/drivers/irqchip/Kconfig
> > > > > @@ -93,6 +93,13 @@ config RENESAS_IRQC
> > > > >     bool
> > > > >     select IRQ_DOMAIN
> > > > >  
> > > > > +config ST_IRQCHIP
> > > > > +   bool
> > > > > +   select REGMAP
> > > > > +   select MFD_SYSCON
> > > > > +   help
> > > > > +     Enables SysCfg Controlled IRQs on STi based platforms.
> > > > > +
> > > > 
> > > > I'm confused by the purpose of this code. It's apparently a driver
> > > > in drivers/irqchip, the Kconfig symbol contains the string IRQCHIP,
> > > > yet it doesn't actually register an irq_chip.
> > > > 
> > > > Also, the name is a bit too generic, ST has lots of different irqchips,
> > > > and this apparently isn't even one of them 
> > > 
> > > Hmm... now you're going to ask me to remember who I had the
> > > conversation with that alluded to this as the best location for this
> > > driver.  Unfortunately, I cannot.  Can you think of a better place to
> > > put it then?
> > 
> > I suspect it's in the right place but should actually be an irqchip
> > driver. I'm having trouble understanding what this code actually does,
> > can you you explain the functionality in more detail so we can figure
> > out what to do with it?
> 
> In the simplest terms it's an IRQ unmasker.  A9 Core IRQs are disabled
> on boot; PMU, CTI (CoreSight), PL310_L2 and EXT.  In order for you to
> make use of them they need to be unmasked in SYSCFG.

So you just apply static configuration once, or are there reasons why you
would mask the interrupts again later?

If it's all static, why doesn't the boot loader unmask all interrupts before
starting the kernel?

	Arnd

[PATCH v2 2/8] irqchip: Supply new driver for STi based devices

[Lee Jones]

On Thu, 27 Nov 2014, Arnd Bergmann wrote:

> On Thursday 27 November 2014 09:29:01 Lee Jones wrote:
> > On Thu, 27 Nov 2014, Arnd Bergmann wrote:
> > > On Thursday 27 November 2014 09:02:55 Lee Jones wrote:
> > > > On Tue, 25 Nov 2014, Arnd Bergmann wrote:
> > > > 
> > > > > On Tuesday 25 November 2014 16:24:59 Lee Jones wrote:
> > > > > 
> > > > > > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > > > > > index b21f12f..e502f15 100644
> > > > > > --- a/drivers/irqchip/Kconfig
> > > > > > +++ b/drivers/irqchip/Kconfig
> > > > > > @@ -93,6 +93,13 @@ config RENESAS_IRQC
> > > > > >     bool
> > > > > >     select IRQ_DOMAIN
> > > > > >  
> > > > > > +config ST_IRQCHIP
> > > > > > +   bool
> > > > > > +   select REGMAP
> > > > > > +   select MFD_SYSCON
> > > > > > +   help
> > > > > > +     Enables SysCfg Controlled IRQs on STi based platforms.
> > > > > > +
> > > > > 
> > > > > I'm confused by the purpose of this code. It's apparently a driver
> > > > > in drivers/irqchip, the Kconfig symbol contains the string IRQCHIP,
> > > > > yet it doesn't actually register an irq_chip.
> > > > > 
> > > > > Also, the name is a bit too generic, ST has lots of different irqchips,
> > > > > and this apparently isn't even one of them 
> > > > 
> > > > Hmm... now you're going to ask me to remember who I had the
> > > > conversation with that alluded to this as the best location for this
> > > > driver.  Unfortunately, I cannot.  Can you think of a better place to
> > > > put it then?
> > > 
> > > I suspect it's in the right place but should actually be an irqchip
> > > driver. I'm having trouble understanding what this code actually does,
> > > can you you explain the functionality in more detail so we can figure
> > > out what to do with it?
> > 
> > In the simplest terms it's an IRQ unmasker.  A9 Core IRQs are disabled
> > on boot; PMU, CTI (CoreSight), PL310_L2 and EXT.  In order for you to
> > make use of them they need to be unmasked in SYSCFG.
> 
> So you just apply static configuration once, or are there reasons why you
> would mask the interrupts again later?
> 
> If it's all static, why doesn't the boot loader unmask all interrupts before
> starting the kernel?

We'd like to configure them at boot-time, via DT.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
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[PATCH v2 3/8] irqchip: irq-st: Add documentation for STi based syscfg IRQs

[Lee Jones]

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 .../interrupt-controller/st,sti-irq-syscfg.txt     | 35 ++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt

diff --git a/Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt b/Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt
new file mode 100644
index 0000000..ced6014
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt
@@ -0,0 +1,35 @@
+STMicroelectronics STi System Configuration Controlled IRQs
+-----------------------------------------------------------
+
+On STi based systems; External, CTI (Core Sight), PMU (Performance Management),
+and PL310 L2 Cache IRQs are controlled using System Configuration registers.
+This driver is used to unmask them prior to use.
+
+Required properties:
+- compatible	: Should be set to one of:
+			"st,stih415-irq-syscfg"
+			"st,stih416-irq-syscfg"
+			"st,stih407-irq-syscfg"
+			"st,stid127-irq-syscfg"
+- st,syscfg	: Phandle to Cortex-A9 IRQ system config registers
+- st,irq-device	: Array of IRQs to enable - should be 2 in length
+- st,fiq-device	: Array of FIQs to enable - should be 2 in length
+
+Optional properties:
+- st,invert-ext	: External IRQs can be inverted at will.  This property inverts
+		  these IRQs using bitwise logic.  A number of defines have been
+		  provided for convenience:
+			ST_IRQ_SYSCFG_EXT_1_INV
+			ST_IRQ_SYSCFG_EXT_2_INV
+			ST_IRQ_SYSCFG_EXT_3_INV
+Example:
+
+irq-syscfg {
+	compatible    = "st,stih416-irq-syscfg";
+	st,syscfg     = <&syscfg_cpu>;
+	st,irq-device = <ST_IRQ_SYSCFG_PMU_0>,
+			<ST_IRQ_SYSCFG_PMU_1>;
+	st,fiq-device = <ST_IRQ_SYSCFG_DISABLED>,
+			<ST_IRQ_SYSCFG_DISABLED>;
+	st,invert-ext = <(ST_IRQ_SYSCFG_EXT_1_INV | ST_IRQ_SYSCFG_EXT_3_INV)>;
+};
-- 
1.9.1

[PATCH v2 4/8] ARM: STi: STiH416: Enable Cortex-A9 PMU support

[Lee Jones]

This is ARM's generic Performance Monitoring Unit.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/boot/dts/stih416.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/stih416.dtsi b/arch/arm/boot/dts/stih416.dtsi
index 84758d7..badefd6 100644
--- a/arch/arm/boot/dts/stih416.dtsi
+++ b/arch/arm/boot/dts/stih416.dtsi
@@ -21,6 +21,12 @@
 		cache-level = <2>;
 	};
 
+	arm-pmu {
+		compatible = "arm,cortex-a9-pmu";
+		interrupt-parent = <&intc>;
+		interrupts = <GIC_PPI 15 IRQ_TYPE_LEVEL_HIGH>;
+	};
+
 	soc {
 		#address-cells = <1>;
 		#size-cells = <1>;
-- 
1.9.1

[PATCH v2 5/8] ARM: STi: STiH416: Enable PMU IRQs

[Lee Jones]

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.

Here we are enabling PMU IRQs on both channels.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/boot/dts/stih416.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/stih416.dtsi b/arch/arm/boot/dts/stih416.dtsi
index badefd6..d98ce91 100644
--- a/arch/arm/boot/dts/stih416.dtsi
+++ b/arch/arm/boot/dts/stih416.dtsi
@@ -11,6 +11,7 @@
 #include "stih416-pinctrl.dtsi"
 #include <dt-bindings/interrupt-controller/arm-gic.h>
 #include <dt-bindings/reset-controller/stih416-resets.h>
+#include <dt-bindings/interrupt-controller/irq-st.h>
 / {
 	L2: cache-controller {
 		compatible = "arm,pl310-cache";
@@ -90,6 +91,15 @@
 			reg		= <0xfe4b5100 0x8>;
 		};
 
+		irq-syscfg {
+			compatible    = "st,stih416-irq-syscfg";
+			st,syscfg     = <&syscfg_cpu>;
+			st,irq-device = <ST_IRQ_SYSCFG_PMU_0>,
+					<ST_IRQ_SYSCFG_PMU_1>;
+			st,fiq-device = <ST_IRQ_SYSCFG_DISABLED>,
+					<ST_IRQ_SYSCFG_DISABLED>;
+		};
+
 		serial2: serial at fed32000{
 			compatible	= "st,asc";
 			status 		= "disabled";
-- 
1.9.1

[PATCH v2 6/8] ARM: STi: STiH407: Enable Cortex-A9 PMU support

[Lee Jones]

This is ARM's generic Performance Monitoring Unit.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/boot/dts/stih407.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/stih407.dtsi b/arch/arm/boot/dts/stih407.dtsi
index 4f9024f..53bfcd9 100644
--- a/arch/arm/boot/dts/stih407.dtsi
+++ b/arch/arm/boot/dts/stih407.dtsi
@@ -56,6 +56,12 @@
 		cache-level = <2>;
 	};
 
+	arm-pmu {
+		interrupt-parent = <&intc>;
+		compatible = "arm,cortex-a9-pmu";
+		interrupts = <GIC_PPI 15 IRQ_TYPE_LEVEL_HIGH>;
+	};
+
 	soc {
 		#address-cells = <1>;
 		#size-cells = <1>;
-- 
1.9.1

[PATCH v2 7/8] ARM: STi: STiH407: Enable PMU IRQs

[Lee Jones]

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.

Here we are enabling PMU IRQs on both channels.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 arch/arm/boot/dts/stih407.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/stih407.dtsi b/arch/arm/boot/dts/stih407.dtsi
index 53bfcd9..e3b235f 100644
--- a/arch/arm/boot/dts/stih407.dtsi
+++ b/arch/arm/boot/dts/stih407.dtsi
@@ -8,6 +8,7 @@
  */
 #include "stih407-clock.dtsi"
 #include "stih407-pinctrl.dtsi"
+#include <dt-bindings/interrupt-controller/irq-st.h>
 / {
 	#address-cells = <1>;
 	#size-cells = <1>;
@@ -104,6 +105,15 @@
 			reg = <0x94b5100 0x1000>;
 		};
 
+		irq-syscfg {
+			compatible    = "st,stih407-irq-syscfg";
+			st,syscfg     = <&syscfg_core>;
+			st,irq-device = <ST_IRQ_SYSCFG_PMU_0>,
+					<ST_IRQ_SYSCFG_PMU_1>;
+			st,fiq-device = <ST_IRQ_SYSCFG_DISABLED>,
+					<ST_IRQ_SYSCFG_DISABLED>;
+		};
+
 		serial at 9830000 {
 			compatible = "st,asc";
 			reg = <0x9830000 0x2c>;
-- 
1.9.1

[PATCH v2 8/8] ARM: STI: Ensure requested STi's SysCfg Controlled IRQs are enabled at boot

[Lee Jones]

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@linaro.org>
---
 arch/arm/mach-sti/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/mach-sti/Kconfig b/arch/arm/mach-sti/Kconfig
index 878e9ec..eae0971 100644
--- a/arch/arm/mach-sti/Kconfig
+++ b/arch/arm/mach-sti/Kconfig
@@ -1,6 +1,7 @@
 menuconfig ARCH_STI
 	bool "STMicroelectronics Consumer Electronics SOCs" if ARCH_MULTI_V7
 	select ARM_GIC
+	select ST_IRQCHIP
 	select ARM_GLOBAL_TIMER
 	select PINCTRL
 	select PINCTRL_ST
-- 
1.9.1

[PATCH v2 0/8] irqchip: New driver for ST's SysCfg controlled IRQs

[Lee Jones]

Jason, would you like me to send this set again?

> This driver enables IRQs which are controlled using System Configuration
> registers.  Without it Performance Monitoring, Core Sight Tracing and some
> L2 Caches will fail to function.
> 
> v1 => v2:
>  - Fixed up Jason's review comments
> 
> Lee Jones (8):
>   dt: bindings: Supply shared ST IRQ defines
>   irqchip: Supply new driver for STi based devices
>   irqchip: irq-st: Add documentation for STi based syscfg IRQs
>   ARM: STi: STiH416: Enable Cortex-A9 PMU support
>   ARM: STi: STiH416: Enable PMU IRQs
>   ARM: STi: STiH407: Enable Cortex-A9 PMU support
>   ARM: STi: STiH407: Enable PMU IRQs
>   ARM: STI: Ensure requested STi's SysCfg Controlled IRQs are enabled at
>     boot
> 
>  .../interrupt-controller/st,sti-irq-syscfg.txt     |  35 ++++
>  arch/arm/boot/dts/stih407.dtsi                     |  16 ++
>  arch/arm/boot/dts/stih416.dtsi                     |  16 ++
>  arch/arm/mach-sti/Kconfig                          |   1 +
>  drivers/irqchip/Kconfig                            |   7 +
>  drivers/irqchip/Makefile                           |   1 +
>  drivers/irqchip/irq-st.c                           | 208 +++++++++++++++++++++
>  include/dt-bindings/interrupt-controller/irq-st.h  |  30 +++
>  8 files changed, 314 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt
>  create mode 100644 drivers/irqchip/irq-st.c
>  create mode 100644 include/dt-bindings/interrupt-controller/irq-st.h
> 

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

[PATCH v2 0/8] irqchip: New driver for ST's SysCfg controlled IRQs

[Jason Cooper]

On Mon, Dec 15, 2014 at 12:28:26PM +0000, Lee Jones wrote:
> Jason, would you like me to send this set again?

Please wait for -rc1 to land, then rebase on that.

thx,

Jason.

[PATCH v2 0/8] irqchip: New driver for ST's SysCfg controlled IRQs

[Lee Jones]

On Mon, 15 Dec 2014, Jason Cooper wrote:

> On Mon, Dec 15, 2014 at 12:28:26PM +0000, Lee Jones wrote:
> > Jason, would you like me to send this set again?
> 
> Please wait for -rc1 to land, then rebase on that.

Can do.  Thanks Jason.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog