| Message ID | 1351416634-3352-2-git-send-email-thomas.petazzoni@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 10/28/2012 04:30 AM, Thomas Petazzoni wrote: > With the recent creation of the drivers/irqchip/ directory, it is > desirable to move irq controller drivers here. At the moment, the only > driver here is irq-bcm2835, the driver for the irq controller found in > the ARM BCM2835 SoC, present in Rasberry Pi systems. This irq > controller driver was exporting its initialization function and its > irq handling function through a header file in > <linux/irqchip/bcm2835.h>. > > When proposing to also move another irq controller driver in > drivers/irqchip, Rob Herring raised the very valid point that moving > things to drivers/irqchip was good in order to remove more stuff from > arch/arm, but if it means adding gazillions of headers files in > include/linux/irqchip/, it would not be very nice. > > So, upon the suggestion of Rob Herring and Arnd Bergmann, this commit > introduces a small infrastructure that defines a central > irqchip_init() function in drivers/irqchip/irqchip.c, which is meant > to be called as the ->init_irq() callback of ARM platforms. This > function calls of_irq_init() with an array that will progressively > contain the compatible strings of each irq controller driver, and also > a reference to the initialization functions of such drivers. The > drivers/irqchip/irqchip.h header file, currently empty, is added to > allow irq controller drivers to expose their initialization function > to the main irqchip.c file. Note that the irq controller driver > initialization function is responsible for setting the global > handle_arch_irq() variable, so that ARM platforms no longer have to > define the ->handle_irq field in their DT_MACHINE structure. > > A global header, <linux/irqchip.h> is also added to expose the single > irqchip_init() function to the reset of the kernel. > > A further commit moves the BCM2835 irq controller driver to this new > small infrastructure, therefore removing the include/linux/irqchip/ > directory. > > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> > Reviewed-by: Stephen Warren <swarren@wwwdotorg.org> > --- > drivers/irqchip/Kconfig | 3 ++- > drivers/irqchip/Makefile | 1 + > drivers/irqchip/irqchip.c | 23 +++++++++++++++++++++++ > drivers/irqchip/irqchip.h | 14 ++++++++++++++ > include/linux/irqchip.h | 16 ++++++++++++++++ > 5 files changed, 56 insertions(+), 1 deletion(-) > create mode 100644 drivers/irqchip/irqchip.c > create mode 100644 drivers/irqchip/irqchip.h > create mode 100644 include/linux/irqchip.h > > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig > index 1bb8bf6..e0ff166 100644 > --- a/drivers/irqchip/Kconfig > +++ b/drivers/irqchip/Kconfig > @@ -1 +1,2 @@ > -# empty > +config USE_IRQCHIP > + bool This should depend on OF_IRQ. Rob
Rob, On Sun, 28 Oct 2012 08:18:42 -0500, Rob Herring wrote: > > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig > > index 1bb8bf6..e0ff166 100644 > > --- a/drivers/irqchip/Kconfig > > +++ b/drivers/irqchip/Kconfig > > @@ -1 +1,2 @@ > > -# empty > > +config USE_IRQCHIP > > + bool > > This should depend on OF_IRQ. It is correct that the mechanism only works for irqchip drivers that are probed through the Device Tree. However, having a "depends on" inside a configuration that gets "select"ed by other configuration options (in our case ARCH_BCM2835 and ARCH_MVEBU select USE_IRQCHIP) is useless: kconfig doesn't care of the "depends on" dependencies when you're "select"ing an option. So, I can add it for documentation purposes, but it is practically useless. Best regards, Thomas
On 10/28/2012 08:24 AM, Thomas Petazzoni wrote: > Rob, > > On Sun, 28 Oct 2012 08:18:42 -0500, Rob Herring wrote: > >>> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig >>> index 1bb8bf6..e0ff166 100644 >>> --- a/drivers/irqchip/Kconfig >>> +++ b/drivers/irqchip/Kconfig >>> @@ -1 +1,2 @@ >>> -# empty >>> +config USE_IRQCHIP >>> + bool >> >> This should depend on OF_IRQ. > > It is correct that the mechanism only works for irqchip drivers that > are probed through the Device Tree. However, having a "depends on" > inside a configuration that gets "select"ed by other configuration > options (in our case ARCH_BCM2835 and ARCH_MVEBU select USE_IRQCHIP) is > useless: kconfig doesn't care of the "depends on" dependencies when > you're "select"ing an option. > > So, I can add it for documentation purposes, but it is practically > useless. It will give a kconfig error rather than build error on of_irq_init which would result in patches for empty of_irq_init. How about default y and depends on OF_IRQ. Then you don't need a select. I think we want all DT enabled platforms to use this and it's only a small amount of init space. Rob > > Best regards, > > Thomas >
Rob, On Sun, 28 Oct 2012 08:30:01 -0500, Rob Herring wrote: > It will give a kconfig error rather than build error on of_irq_init > which would result in patches for empty of_irq_init. Right. > How about default y and depends on OF_IRQ. Then you don't need a select. > I think we want all DT enabled platforms to use this and it's only a > small amount of init space. Sounds good. Will do and post a v3. Thomas
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index 1bb8bf6..e0ff166 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -1 +1,2 @@ -# empty +config USE_IRQCHIP + bool diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile index 054321d..77adcb1 100644 --- a/drivers/irqchip/Makefile +++ b/drivers/irqchip/Makefile @@ -1 +1,2 @@ +obj-$(CONFIG_USE_IRQCHIP) += irqchip.o obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2835.o diff --git a/drivers/irqchip/irqchip.c b/drivers/irqchip/irqchip.c new file mode 100644 index 0000000..410f99f --- /dev/null +++ b/drivers/irqchip/irqchip.c @@ -0,0 +1,23 @@ +/* + * Copyright (C) 2012 Thomas Petazzoni + * + * Thomas Petazzoni <thomas.petazzoni@free-electrons.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/init.h> +#include <linux/of_irq.h> + +#include "irqchip.h" + +static const struct of_device_id irqchip_of_match[] __initconst = { + {}, +}; + +void __init irqchip_init(void) +{ + of_irq_init(irqchip_of_match); +} diff --git a/drivers/irqchip/irqchip.h b/drivers/irqchip/irqchip.h new file mode 100644 index 0000000..1e7a5c2 --- /dev/null +++ b/drivers/irqchip/irqchip.h @@ -0,0 +1,14 @@ +/* + * Copyright (C) 2012 Thomas Petazzoni + * + * Thomas Petazzoni <thomas.petazzoni@free-electrons.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#ifndef _IRQCHIP_H +#define _IRQCHIP_H + +#endif diff --git a/include/linux/irqchip.h b/include/linux/irqchip.h new file mode 100644 index 0000000..e0006f1 --- /dev/null +++ b/include/linux/irqchip.h @@ -0,0 +1,16 @@ +/* + * Copyright (C) 2012 Thomas Petazzoni + * + * Thomas Petazzoni <thomas.petazzoni@free-electrons.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#ifndef _LINUX_IRQCHIP_H +#define _LINUX_IRQCHIP_H + +void irqchip_init(void); + +#endif